Patent Application
20230212469
Waste materials, especially non-biodegradable waste materials, can negatively impact the environment when disposed of in landfills after a single use. Thus, from an environmental standpoint, it is desirable to recycle as much waste material as possible. However, there still exist streams of low value waste that are nearly impossible or economically unfeasible to recycle with conventional recycling technologies. In addition, some conventional recycling processes produce waste streams that are themselves not economically feasible to recover or recycle, resulting in additional waste streams that must be disposed of or otherwise handled.
Partial oxidation gasification is a process that can be used to produce a synthesis gas from a carbon-containing feedstock. Traditional feedstocks include carbon-containing fossil fuels, such as natural gas and coal. Although plastic materials and other wastes have been used in gasification feedstocks, these processes generally comprise relatively low plastic content and/or contain various impurities that may produce undesirable gasification products. Thus, there is a need for improved processes and facilities for partial oxidation gasification of plastic from waste streams.
In one aspect, the present technology concerns a method of producing synthesis gas from a plastic material. The method comprises: (a) providing a separated waste plastic from a waste plastic separation process; (b) performing one or both of: (i) size-reducing the separated waste plastic and producing a size-reduced wet waste plastic stream, and combining the size-reduced wet waste plastic with a quantity of coal to produce a wet plastic-coal mixture; and/or (ii) combining a quantity of coal with at least a portion of the separated waste plastic to produce a plastic-coal mixture, wherein the separated waste plastic is a wet waste plastic prior to combining with coal; and (c) feeding at least a portion of the wet plastic-coal mixture to a partial oxidation (POX) gasifier.
In one aspect, the present technology concerns a method of producing synthesis gas from a plastic material. The method comprises (a) feeding a feedstock comprising wet waste plastic and molecular oxygen into a partial oxidation gasifier; and (b) performing a partial oxidation reaction within the gasifier by reacting at least a portion of the plastic material and at least a portion of the molecular oxygen to form the synthesis gas. The wet waste plastic comprises the plastic material and a liquid medium. The feedstock comprises greater than 25 weight percent plastic based on the weight of all solids present in the feedstock.
In one aspect, the present technology concerns a method of producing synthesis gas from a plastic material. The method comprises: (a) combining a wet waste plastic and a quantity of coal to form a wet plastic-coal mixture; (b) feeding the wet plastic-coal mixture and molecular oxygen into a partial oxidation gasifier; and (c) performing a partial oxidation reaction within the gasifier by reacting the plastic material and at least a portion of the molecular oxygen to form the synthesis gas. The wet waste plastic comprises the plastic material and a liquid medium.
In one aspect, the present technology concerns a method of producing synthesis gas from a plastic material. The method comprises: (a) mixing at least a portion of the plastic material and a liquid medium to form a plastic-containing slurry; (b) either: (i) directly feeding the plastic-containing slurry and molecular oxygen into a partial oxidation gasifier; or (ii) combining the plastic-containing slurry with a coal-containing slurry to form a plastic and coal slurry, and feeding the plastic and coal slurry into the partial oxidation gasifier; and (c) performing a partial oxidation reaction within the gasifier by reacting at least a portion of the plastic material and at least a portion of the molecular oxygen to form the synthesis gas.
In one aspect, the present technology concerns a synthesis gas formed by any of the methods above.
We have discovered new methods and systems for partial oxidation gasification of plastic waste feedstocks. The plastic waste feedstocks may comprise plastic waste from a plastic separation process and/or may be in the form of a wet waste plastic, such as a plastic-containing slurry. Additionally, or in the alternative, the plastic waste feedstock may be in the form of a liquified plastic stream. The plastic-containing feedstocks may be fed directly to the partial oxidation gasifier, or they may be combined with a quantity of coal or a coal-containing slurry for form a plastic-coal mixture or plastic and coal slurry before being fed to the partial oxidation gasifier.
When a numerical sequence is indicated, it is to be understood that each number is modified the same as the first number or last number in the numerical sequence or in the sentence, e.g. each number is “at least,” or “up to” or “not more than” as the case may be; and each number is in an “or” relationship. For example, “at least 10, 20, 30, 40, 50, 75 wt. % . . . ” means the same as “at least 10 wt. %, or at least 20 wt. %, or at least 30 wt. %, or at least 40 wt. %, or at least 50 wt. %, or at least 75 wt. %,” etc.; and “not more than 90 wt. %, 85, 70, 60 . . . ” means the same as “not more than 90 wt. %, or not more than 85 wt. %, or not more than 70 wt. % . . . ” etc.; and “at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% by weight . . . ” means the same as “at least 1 wt. %, or at least 2 wt. %, or at least 3 wt. % . . . ” etc.; and “at least 5, 10, 15, 20 and/or not more than 99, 95, 90 weight percent” means the same as “at least 5 wt. %, or at least 10 wt. %, or at least 15 wt. % or at least 20 wt. % and/or not more than 99 wt. %, or not more than 95 wt. %, or not more than 90 weight percent . . . ” etc.
All concentrations or amounts are by weight unless otherwise stated.
Turning now to
As shown in
As used herein, the term “chemical recycling” refers to a waste plastic recycling process that includes a step of chemically converting waste plastic polymers into lower molecular weight polymers, oligomers, monomers, and/or non-polymeric molecules (e.g., hydrogen and carbon monoxide) that are useful by themselves and/or are useful as feedstocks to another chemical production process or processes. A “chemical recycling facility,” is a facility for producing a recycle content product via chemical recycling of waste plastic. As used herein, the terms “recycle content” and “r-content” mean being or comprising a composition that is directly and/or indirectly derived from waste plastic.
As used herein, the term “directly derived” ‘means having at least one physical component originating from waste plastic, while “indirectly derived” means having an assigned recycle content that i) is attributable to waste plastic, but ii) that is not based on having a physical component originating from waste plastic.
Chemical recycling facilities are not mechanical recycling facilities. As used herein, the terms “mechanical recycling” and “physical recycling” refer to a recycling process that includes a step of melting waste plastic and forming the molten plastic into a new intermediate product (e.g., pellets or sheets) and/or a new end product (e.g., bottles). Generally, mechanical recycling does not substantially change the chemical structure of the plastic being recycled. In one embodiment or in combination with any of the mentioned embodiments, the chemical recycling facilities described herein may be configured to receive and process waste streams from and/or that are not typically processable by a mechanical recycling facility.
Although described herein as being part of a single chemical recycling facility, it should be understood that one or more of the preprocessing facility 20, the solvolysis facility 30, the pyrolysis facility 60, the cracking facility 70, the partial oxidation (POX) gasification facility 50, and the energy recovery facility 80, or any of the other facility 90 such as solidification or separation, may be located in a different geographical location and/or be operated by a different commercial entity. Each of the preprocessing facility 20, the solvolysis facility 30, the pyrolysis facility 60, the cracking facility 70, the partial oxidation (POX) gasification facility 50, the energy recovery facility 80, or any other facility 90s may be operated by the same entity, while, in other cases, one or more of the preprocessing facility 20, the solvolysis facility 30, the pyrolysis facility 60, the cracking facility 70, the partial oxidation (POX) gasification facility 50, a solidification facility, the energy recovery facility 80, and one or more other facility 90 such as separation or solidification, may be operated by a different commercial entity.
In an embodiment or in combination with any embodiment mentioned herein, the chemical recycling facility 10 may be a commercial-scale facility capable of processing significant volumes of mixed plastic waste. As used herein, the term “commercial scale facility” refers to a facility having an average annual feed rate of at least 500 pounds per hour, averaged over one year. The average feed rate to the chemical recycling facility (or to any one of the preprocessing facility 20, the solvolysis facility 30, the pyrolysis facility 60, the cracking facility 70, the POX gasification facility 50, the energy recovery facility 80, and any other facility 90) can be at least 750, at least 1,000, at least 1,500, at least 2,000, at least 2,500, at least 3,000, at least 3,500, at least 4,000, at least 4,500, at least 5,000, at least 5,500, at least 6,000, at least 6,500, at least 7,500, at least 10,000, at least 12,500, at least 15,000, at least 17,500, at least 20,000, at least 22,500, at least 25,000, at least 27,500, at least 30,000 or at least 32,500 pounds per hour and/or not more than 1,000,000, not more than 750,000, not more than 500,000, not more than 450,000, not more than 400,000, not more than 350,000, not more than 300,000, not more than 250,000, not more than 200,000, not more than 150,000, not more than 100,000, not more than 75,000, not more than 50,000, or not more than 40,000 pounds per hour. When a facility includes two or more feed streams, the average annual feed rate is determined based on the combined weight of the feed streams.
Additionally, it should be understood that each of the preprocessing facility 20, the solvolysis facility 30, the pyrolysis facility 60, the cracking facility 70, the POX gasification facility 50, the energy recovery facility 80, and any other facility 90 may include multiple units operating in series or parallel. For example, the pyrolysis facility 60 may include multiple pyrolysis reactors/units operating in parallel and each receiving a feed comprising waste plastic. When a facility is made up of multiple individual units, the average annual feed rate to the facility is calculated as the sum of the average annual feed rates to all of the common types of units within that facility.
Additionally, in an embodiment or in combination with any embodiment mentioned herein, the chemical recycling facility 10 (or any one of the preprocessing facility 20, the solvolysis facility 30, the pyrolysis facility 60, the cracking facility 70, the POX gasification facility 50, the energy recovery facility 80, and any other facility 90) may be operated in a continuous manner. Additionally, or in the alternative, at least a portion of the chemical recycling facility 10 (or any of the preprocessing facility 20, the solvolysis facility 30, the pyrolysis facility 60, the cracking facility 70, the POX gasification facility 50, the energy recovery facility 80, and any other facility 90) may be operated in a batch or semi-batch manner. In some cases, the facility may include a plurality of tanks between portions of a single facility or between two or more different facilities to manage inventory and ensure consistent flow rates into each facility or portion thereof.
In addition, two or more of the facilities shown in
Regarding (i), examples of suitable utility services include, but are not limited to, steam systems (co-generation and distribution systems), cooling water systems, heat transfer fluid systems, plant or instrument air systems, nitrogen systems, hydrogen systems, non-residential electrical generation and distribution, including distribution above 8000V, non-residential wastewater/sewer systems, storage facilities, transport lines, flare systems, and combinations thereof.
Regarding (ii), examples of service groups and facilities include, but are not limited to, emergency services personnel (fire and/or medical), a third-party vendor, a state or local government oversight group, and combinations thereof. Government oversight groups can include, for example, regulatory or environmental agencies, as well as municipal and taxation agencies at the city, county, and state level.
Regarding (iii), the boundary may be, for example, a fence line, a property line, a gate, or common boundaries with at least one boundary of a third-party owned land or facility.
Regarding (iv), the conduit may be a fluid conduit that carries a gas, a liquid, a solid/liquid mixture (e.g., slurry), a solid/gas mixture (e.g., pneumatic conveyance), a solid/liquid/gas mixture, or a solid (e.g., belt conveyance). In some cases, two units may share one or more conduits selected from the above list. Fluid conduits may be used to transport process streams or utilities between the two units. For example, an outlet of one facility (e.g., the solvolysis facility 30) may be fluidly connected via a conduit with an inlet of another facility (e.g., the POX gasification facility 50). In some cases, an interim storage system for the materials being transported within the conduit between the outlet of one facility and the inlet of another facility may be provided. The interim storage system may comprise, for example, one or more tanks, vessels (open or closed), buildings, or containers that are configured to store the material carried by the conduit. In some cases, the interim storage between the outlet of one facility and the inlet of another can be not more than 90, not more than 75, not more than 60, not more than 40, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2 days or not more than 1 day.
Turning again to
As used herein, the terms “mixed plastic waste” and “MPW” refer to a mixture of at least two types of waste plastics including, but not limited to the following plastic types: polyethylene terephthalate (PET), one or more polyolefins (PO), and polyvinylchloride (PVC). In an embodiment or in combination with any embodiment mentioned herein, MPW includes at least two distinct types of plastic, with each type of plastic being present in an amount of at least 1, at least 2, at least 5, at least 10, at least 15, or at least 20 weight percent, based on the total weight of plastic in the MPW.
In an embodiment or in combination with any embodiment mentioned herein, MPW comprises at least 1, at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent PET and/or at least 1, at least 2, at least 5, at least 10, at least 15, or at least 20 weight percent PO, based on the total weight of plastic in the MPW. In one embodiment or more embodiments, MPW may also include minor amounts of one or more types of plastic components other than PET and PO (and optionally PVC) that total less than 50, less than 45, less than 40, less than 35, less than 30, less than 25, less than 20, less than 15, less than 10, less than 5, less than 2, or less than 1 weight percent, based on the total weight of plastic in the MPW.
In an embodiment or in combination with any embodiment mentioned herein, the MPW comprises at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent PET, based on the total weight of the stream. Alternatively, or in addition, the MPW comprises not more than 99.9, not more than 99, not more than 97, not more than 92, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, or not more than 5 weight percent PET, based on the total weight of the stream.
The MPW stream can include non-PET components in an amount of at least 0.1, at least 0.5, at least 1, at least 2, at least 5, at least 7, at least 10, at least 15, at least 20, at least 25, at least 30, or at least 35 and/or not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, or not more than 7 weight percent, based on the total weight of the stream. Non-PET components can be present in an amount between 0.1 and 50 weight percent, 1 and 20 weight percent, or 2 and 10 weight percent, based on the total weight of the stream. Examples of such non-PET components can include, but are not limited to, ferrous and non-ferrous metals, inerts (such as rocks, glass, sand, etc.), plastic inerts (such as titanium dioxide, silicon dioxide, etc.), olefins, adhesives, compatibilizers, biosludge, cellulosic materials (such as cardboard, paper, etc.), and combinations thereof.
In an embodiment or in combination with any embodiment mentioned herein, all or a portion of the MPW can originate from a municipal source or comprise municipal waste. The municipal waste portion of the MPW can include, for example, PET in an amount of from 45 to 95 weight percent, 50 to 90 weight percent, or 55 to 85 weight percent, based on the total weight of the municipal waste stream (or portion of the stream).
In an embodiment or in combination with any embodiment mentioned herein, all or a portion of the MPW can originate from a municipal recycling facility (MRF) and may include, for example, PET in an amount of from 65 to 99.9 weight percent, 70 to 99 weight percent, or 80 to 97 weight percent, based on the total weight of the stream. The non-PET components in such streams may include, for example, other plastics in an amount of at least 1, at least 2, at least 5, at least 7, or at least 10 weight percent and/or not more than 25, not more than 22, not more than 20, not more than 15, not more than 12, or not more than 10 weight percent, based on the total weight of the stream, or such may be present in an amount in the range of from 1 to 22 weight percent, 2 to 15 weight percent, or 5 to 12 weight percent, based on the total weight of the stream. In an embodiment or in combination with any embodiment mentioned herein, the non-PET components can include other plastics in an amount in the range of from 2 to 35 weight percent, 5 to 30 weight percent, or 10 to 25 weight percent, based on the total weight of the stream, particularly when, for example, the MPW includes colored sorted plastics.
In an embodiment or in combination with any embodiment mentioned herein, all or a portion of the MPW can originate from a reclaimer facility and may include, for example, PET in an amount of from 85 to 99.9 weight percent, 90 to 99.9 weight percent, or 95 to 99 weight percent, based on the total weight of the stream. The non-PET components in such streams may include, for example, other plastics in an amount of at least 1, at least 2, at least 5, at least 7, or at least 10 weight percent and/or not more than 25, not more than 22, not more than 20, not more than 15, not more than 12, or not more than 10 weight percent, based on the total weight of the stream, or such may be present in an amount in the range of from 1 to 22 weight percent, 2 to 15 weight percent, or 5 to 12 weight percent, based on the total weight of the stream.
As used herein, the term “plastic” may include any organic synthetic polymers that are solid at 25° C. and 1 atmosphere of pressure. In an embodiment or in combination with any embodiment mentioned herein, the polymers may have a number average molecular weight (Mn) of at least 75, or at least 100, or at least 125, or at least 150, or at least 300, or at least 500, or at least 1000, or at least 5,000, or at least 10,000, or at least 20,000, or at least 30,000, or at least 50,000 or at least 70,000 or at least 90,000 or at least 100,000 or at least 130,000 Daltons. The weight average molecular weight (Mw) of the polymers can be at least 300, or at least 500, or at least 1000, or at least 5,000, or at least 10,000, or at least 20,000, or at least 30,000 or at least 50,000, or at least 70,000, or at least 90,000, or at least 100,000, or at least 130,000, or at least 150,000, or at least 300,000 Daltons.
Examples of suitable plastics can include, but are not limited to, aromatic and aliphatic polyesters, polyolefins, polyvinyl chloride (PVC), polystyrene, polytetrafluoroethylene, acrylobutadienestyrene (ABS), cellulosics, epoxides, polyamides, phenolic resins, polyacetal, polycarbonates, polyphenylene-based alloys, poly(methyl methacrylate), styrene-containing polymers, polyurethane, vinyl-based polymers, styrene acrylonitrile, thermoplastic elastomers other than tires, and urea containing polymers and melamines.
Examples of polyesters can include those having repeating aromatic or cyclic units such as those containing a repeating terephthalate, isophthalate, or naphthalate units such as PET, modified PET, and PEN, or those containing repeating furanate repeating units. Polyethylene terephthalate (PET) is also an example of a suitable polyester. As used herein, “PET” or “polyethylene terephthalate” refers to a homopolymer of polyethylene terephthalate, or to a polyethylene terephthalate modified with one or more acid and/or glycol modifiers and/or containing residues or moieties of other than ethylene glycol and terephthalic acid, such as isophthalic acid, 1,4-cyclohexanedicarboxylic acid, diethylene glycol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCD), cyclohexanedimethanol (CHDM), propylene glycol, isosorbide, 1,4-butanediol, 1,3-propane diol, and/or neopentyl glycol (NPG).
Also included within the definition of the terms “PET” and “polyethylene terephthalate” are polyesters having repeating terephthalate units (whether or not they contain repeating ethylene glycol-based units) and one or more residues or moieties of a glycol including, for example, TMCD, CHDM, propylene glycol, or NPG, isosorbide, 1,4-butanediol, 1,3-propane diol, and/or diethylene glycol, or combinations thereof. Examples of polymers with repeat terephthalate units can include, but are not limited to, polypropylene terephthalate, polybutylene terephthalate, and copolyesters thereof. Examples of aliphatic polyesters can include, but are not limited to, polylactic acid (PLA), polyglycolic acid, polycaprolactones, and polyethylene adipates. The polymer may comprise mixed aliphatic-aromatic copolyesters including, for example, mixed terephthalates/adipates.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic may comprise at least one type of plastic that has repeat terephthalate units with such a plastic being present in an amount of at least 1, at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, or at least 30 and/or not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, or not more than 2 weight percent, based on the total weight of the stream, or it can be present in the range of from 1 to 45 weight percent, 2 to 40 weight percent, or 5 to 40 weight percent, based on the total weight of the stream. Similar amounts of copolyesters having multiple cyclohexane dimethanol moieties, 2,2,4,4-tetramethyl-1,3-cyclobutanediol moieties, or combinations thereof may also be present.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic may comprise at least one type of plastic that has repeat terephthalate units with such a plastic being present in an amount of at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, or at least 90 and/or not more than 99.9, not more than 99, not more than 97, not more than 95, not more than 90, or not more than 85 weigh percent, based on the total weight of the stream, or it can be present in the range of from 30 to 99.9 weight percent, 50 to 99.9 weight percent, or 75 to 99 weight percent, based on the total weight of the stream.
In an embodiment of in combination with any embodiment mentioned herein, the waste plastic may comprise terephthalate repeat units in an amount of at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, or at least 45 and/or not more than 75, not more than 72, not more than 70, not more than 60, or not more than 65 weight percent, based on the total weight of the plastic in the waste plastic stream, or it may include terephthalate repeat units in an amount in the range of from 1 to 75 weight percent, 5 to 70 weight percent, or 25 to 75 weight percent, based on the total weight of the stream.
Examples of specific polyolefins may include low density polyethylene (LDPE), high density polyethylene (HDPE), atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, crosslinked polyethylene, amorphous polyolefins, and the copolymers of any one of the aforementioned polyolefins. The waste plastic may include polymers including linear low-density polyethylene (LLDPE), polymethylpentene, polybutene-1, and copolymers thereof. The waste plastic may comprise flashspun high density polyethylene.
The waste plastic may include thermoplastic polymers, thermosetting polymers, or combinations thereof. In an embodiment or in combination with any embodiment mentioned herein, the waste plastic can include at least 0.1, at least 1, at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, or at least 30 and/or not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, or not more than 2 weight percent of one or more thermosetting polymers, based on the total weight of the stream, or it can be present in an amount of 0.1 to 45 weight percent, 1 to 40 weight percent, 2 to 35 weight percent, or 2 to 20 weight percent, based on the total weight of the stream.
Alternatively, or in addition, the waste plastic may include at least 0.1, at least 1, at least 2, at least 5, at least 10, at least 15, at least 20, at least 25, or at least 30 and/or not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, or not more than 2 weight percent of cellulose materials, based on the total weight of the stream, or it can be present in an amount in the range of from 0.1 to 45 weight percent, 1 to 40 weight percent, or 2 to 15 weight percent, based on the total weight of the stream. Examples of cellulose materials may include cellulose acetate, cellulose diacetate, cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate, as well as regenerated cellulose such as viscose. Additionally, the cellulose materials can include cellulose derivatives having an acyl degree of substitution of less than 3, not more than 2.9, not more than 2.8, not more than 2.7, or not more than 2.6 and/or at least 1.7, at least 1.8, or at least 1.9, or from 1.8 to 2.8, or 1.7 to 2.9, or 1.9 to 2.9.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic may comprise STYROFOAM or expanded polystyrene.
The waste plastic may originate from one or more of several sources. In an embodiment or in combination with any embodiment mentioned herein, the waste plastic may originate from plastic bottles, diapers, eyeglass frames, films, packaging materials, carpet (residential, commercial, and/or automotive), textiles (clothing and other fabrics) and combinations thereof.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic (e.g., MPW) fed to the chemical recycling facility may include one or more plastics having or obtained from plastics having a resin ID code numbered 1-7 with the chasing arrow triangle established by the SPI. The waste plastic may include one or more plastics that are not generally mechanically recycled. Such plastics can include, but are not limited to, plastics with the resin ID code 3 (polyvinyl chloride), resin ID code 5 (polypropylene), resin ID code 6 (polystyrene), and/or resin ID code 7 (other). In an embodiment or in combination with any embodiment mentioned herein, plastics having at least 1, at least 2, at least 3, at least 4, or at least 5 of the resin ID codes 3-7 or 3, 5, 6, 7, or a combination thereof may be present in the waste plastic in an amount of at least 0.1, at least 0.5, at least 1, at least 2, at least 3, at least 5, at least 7, at least 10, at least 12, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 and/or not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, or not more than 35 weight percent, based on the total weight of all plastics, or it could be in an amount of 0.1 to 90 weight percent, 1 to 75 weight percent, or 2 to 50 weight percent, based on the total weight of plastics.
In an embodiment or in combination with any embodiment mentioned herein, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, or at least 35 and/or not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, or not more than 5 weight percent of the total plastic components in the waste plastic fed to the chemical recycling facility may comprise plastics not having a resin ID code 3, 5, 6, and/or 7 (e.g., where a plastic is not classified). At least 0.1, at least 0.5, at least 1, at least 2, at least 3, at least 4, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, or at least 35 and/or not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, or not more than 5 weight percent of the total plastic components in the waste plastic fed to the chemical recycling facility 10 may comprise plastics not having a resin ID code 4-7, or it can be in the range of 0.1 to 60 weight percent, 1 to 55 weight percent, or 2 to 45 weight percent, based on the total weight of plastic components.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic (e.g., MPW) fed to the chemical recycling facility may comprise plastic that is not classified as resin ID codes 3-7 or ID codes 3, 5, 6, or 7. The total amount of plastic not classified as resin ID code 3-7 or ID codes 3, 5, 6, or 7 plastics in the waste plastic can be at least 0.1, at least 0.5, at least 1, at least 2, at least 3, at least 4, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, or at least 75 and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, or not more than 35 weight percent, based on the total weight of plastic in the waste plastic stream, or it can be in the range of from 0.1 to 95 weight percent, 0.5 to 90 weight percent, or 1 to 80 weight percent, based on the total weight of plastic in the waste plastic stream.
In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises plastics having or obtained from plastics having at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent of at least one, at least two, at least three, or at least four different kinds of resin ID codes.
In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises multi-component polymers. As used herein, the term “multi-component polymers” refers to articles and/or particulates comprising at least one synthetic or natural polymer combined with, attached to, or otherwise physically and/or chemically associated with at least one other polymer and/or non-polymer solid. The polymer can be a synthetic polymer or plastic, such as PET, olefins, and/or nylons. The non-polymer solid can be a metal, such as aluminum, or other non-plastic solids as described herein. The multi-component polymers can include metalized plastics.
In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises multi-component plastics in the form of multi-layer polymers. As used herein, the term “multi-layer polymers” refers to multi-component polymers comprising PET and at least one other polymer and/or non-polymer solid physically and/or chemically associated together in two or more physically distinct layers. A polymer or plastic is considered a multi-layered polymer even though a transition zone may exist between two layers, such as may be present in adhesively adhered layers or co-extruded layers. An adhesive between two layers is not deemed to be a layer. The multi-layer polymers may comprise a layer comprising PET and a one or more additional layers at least one of which is a synthetic or natural polymer that is different from PET, or a polymer which has no ethylene terephthalate repeating units, or a polymer which has no alkylene terephthalate repeating units (a “non-PET polymer layer”), or other non-polymer solid.
Examples of non-PET polymer layers include nylons, polylactic acid, polyolefins, polycarbonates, ethylene vinyl alcohol, polyvinyl alcohol, and/or other plastics or plastic films associated with PET-containing articles and/or particulates, and natural polymers such as whey proteins. The multi-layer polymers may include metal layers, such as aluminum, provided that at least one additional polymer layer is present other than the PET layer. The layers may be adhered with adhesive bonding or other means, physically adjacent (i.e., articles pressed against the film), tackified (i.e., the plastics heated and stuck together), co-extruded plastic films, or otherwise attached to the PET-containing articles. The multi-layer polymers may comprise PET films associated with articles containing other plastics in the same or similar manner. The MPW may comprise multi-component polymers in the form of PET and at least one other plastic, such as polyolefins (e.g., polypropylene) and/or other synthetic or natural polymers, combined in a single physical phase. For example, the MPW comprises a heterogenous mixture comprising a compatibilizer, PET, and at least one other synthetic or natural polymer plastic (e.g., non-PET plastic) combined in a single physical phase. As used herein, the term “compatibilizer” refers to an agent capable of combining at least two otherwise immiscible polymers together in a physical mixture (i.e., blend).
In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises not more than 20, not more than 10, not more than 5, not more than 2, not more than 1, or not more than 0.1 weight percent nylons, on a dry plastic basis. In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises from 0.01 to 20, from 0.05 to 10, from 0.1 to 5, or from 1 to 2 weight percent nylons, on a dry plastic basis.
In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises not more than 40, not more than 20, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent multi-component plastics, on a dry plastic basis. In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises from 0.1 to 40, from 1 to 20, or from 2 to 10 weight percent multi-component plastics, on a dry plastic basis. In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises not more than 40, not more than 20, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent multi-layer plastics, on a dry plastic basis. In one embodiment or in combination with any of the mentioned embodiments, the MPW comprises from 0.1 to 40, from 1 to 20, or from 2 to 10 weight percent multi-layer plastics, on a dry plastic basis.
In one embodiment or in combination with any of the mentioned embodiments, the MPW feedstock to the chemical recycling facility 10 in stream 100 comprises not more than 20, not more than 15, not more than 12, not more than 10, not more than 8, not more than 6, not more than 5, not more than 4, not more than 3, not more than 2, or not more than 1 weight percent of biowaste materials, with the total weight of the MPW feedstock taken as 100 weight percent on a dry basis. The MPW feedstock comprises from 0.01 to 20, from 0.1 to 10, from 0.2 to 5, or from 0.5 to 1 weight percent of biowaste materials, with the total weight of the MPW feedstock taken as 100 weight percent on a dry basis. As used herein, the term “biowaste” refers to material derived from living organisms or of organic origin. Exemplary biowaste materials include, but are not limited to, cotton, wood, saw dust, food scraps, animals and animal parts, plants and plant parts, and manure.
In one embodiment or in combination with any of the mentioned embodiments, the MPW feedstock comprises not more than 20, not more than 15, not more than 12, not more than 10, not more than 8, not more than 6, not more than 5, not more than 4, not more than 3, not more than 2, or not more than 1 weight percent of manufactured cellulose products, with the total weight of the MPW feedstock taken as 100 weight percent on a dry basis. The MPW feedstock comprises from 0.01 to 20, from 0.1 to 10, from 0.2 to 5, or from 0.5 to 1 weight percent of manufactured cellulose products, with the total weight of the MPW feedstock taken as 100 weight percent on a dry basis. As used herein, the term “manufactured cellulose products” refers to nonnatural (i.e., manmade or machine-made) articles, and scraps thereof, comprising cellulosic fibers. Exemplary manufactured cellulose products include, but are not limited to, paper and cardboard.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic (e.g., MPW) fed to the chemical recycling facility can include at least 0.001, at least 0.01, at least 0.05, at least 0.1, or at least 0.25 weight percent and/or not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1, not more than 0.75, or not more than 0.5 weight percent of polyvinyl chloride (PVC) based on the total weight of plastics in the waste plastic feed.
Additionally, or in the alternative, the waste plastic (e.g., MPW) fed to the chemical recycling facility can include at least 0.1, at least 1, at least 2, at least 4, or at least 6 weight percent and/or not more than 25, not more than 15, not more than 10, not more than 5, or not more than 2.5 weight percent of non-plastic solids. Non-plastic solids may include inert filler materials (e.g., calcium carbonate, hydrous aluminum silicate, alumina trihydrate, calcium sulfate), rocks, glass, and/or additives (e.g., thixotropes, pigments and colorants, fire retardants, suppressants, UV inhibitors & stabilizers, conductive metal or carbon, release agents such as zinc stearate, waxes, and silicones).
In one embodiment or in combination with any of the mentioned embodiments, the MPW may comprise at least 0.01, at least 0.1, at least 0.5, or at least 1 and/or not more than 25, not more than 20, not more than 25, not more than 10, not more than 5, or not more than 2.5 weight percent of liquids, based on the total weight of the MPW stream or composition. The amount of liquids in the MPW can be in the range of from 0.01 to 25 weight percent, from 0.5 to 10 weight percent, or 1 to 5 weight percent, based on the total weight of the MPW stream 100.
In one embodiment or in combination with any of the mentioned embodiments, the MPW may comprise at least 35, at least 40, at least 45, at least 50, or at least 55 and/or not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, or not more than 35 weight percent of liquids, based on the total weight of the waste plastic. The liquids in the waste plastic can be in the range of from 35 to 65 weight percent, 40 to 60 weight percent, or 45 to 55 weight percent, based on the total weight of the waste plastic.
In one embodiment or in combination with any of the mentioned embodiments, the amount of textiles (including textile fibers) in the MPW stream in line 100 can be at least 0.1 weight percent, or at least 0.5 weight percent, or at least 1 weight percent, or at least 2 weight percent, or at least 5 weight percent, or at least 8 weight percent, or at least 10 weight percent, or at least 15 weight percent, or at least 20 weight percent material obtained from textiles or textile fibers, based on the weight of the MPW. The amount of textiles (including textile fibers) in the MPW in stream 100 is not more than 50, not more than 40, not more than 30, not more than 20, not more than 15, not more than 10, not more than 8, not more than 5, not more than 2, not more than 1, not more than 0.5, not more than 0.1, not more than 0.05, not more than 0.01, or not more than 0.001 weight percent, based on the weight of the MPW stream 100. The amount of textiles in the MPW stream 100 can be in the range of from 0.1 to 50 weight percent, 5 to 40 weight percent, or 10 to 30 weight percent, based on the total weight of the MPW stream 100.
The MPW introduced into the chemical recycling facility 10 may contain recycle textiles. Textiles may contain natural and/or synthetic fibers, rovings, yarns, nonwoven webs, cloth, fabrics and products made from or containing any of the aforementioned items. Textiles can be woven, knitted, knotted, stitched, tufted, may include pressed fibers such as in felting, embroidered, laced, crocheted, braided, or may include nonwoven webs and materials. Textiles can include fabrics, and fibers separated from a textile or other product containing fibers, scrap or off-spec fibers or yarns or fabrics, or any other source of loose fibers and yarns. A textile can also include staple fibers, continuous fibers, threads, tow bands, twisted and/or spun yarns, gray fabrics made from yarns, finished fabrics produced by wet processing gray fabrics, and garments made from the finished fabrics or any other fabrics. Textiles include apparels, interior furnishings, and industrial types of textiles. Textiles can include post-industrial textiles (pre-consumer) or post-consumer textiles or both.
In one embodiment or in combination with any of the mentioned embodiments, textiles can include apparel, which can generally be defined as things humans wear or made for the body. Such textiles can include sports coats, suits, trousers and casual or work pants, shirts, socks, sportswear, dresses, intimate apparel, outerwear such as rain jackets, cold temperature jackets and coats, sweaters, protective clothing, uniforms, and accessories such as scarves, hats, and gloves. Examples of textiles in the interior furnishing category include furniture upholstery and slipcovers, carpets and rugs, curtains, bedding such as sheets, pillow covers, duvets, comforters, mattress covers; linens, tablecloths, towels, washcloths, and blankets. Examples of industrial textiles include transportation (auto, airplane, train, bus) seats, floor mats, trunk liners, and headliners; outdoor furniture and cushions, tents, backpacks, luggage, ropes, conveyor belts, calendar roll felts, polishing cloths, rags, soil erosion fabrics and geotextiles, agricultural mats and screens, personal protective equipment, bullet proof vests, medical bandages, sutures, tapes, and the like.
The nonwoven webs that are classified as textiles do not include the category of wet laid nonwoven webs and articles made therefrom. While a variety of articles having the same function can be made from a dry or wet laid process, an article made from a dry laid nonwoven web is classified as a textile. Examples of suitable articles that may be formed from dry laid nonwoven webs as described herein can include those for personal, consumer, industrial, food service, medical, and other end uses. Specific examples can include, but are not limited to, baby wipes, flushable wipes, disposable diapers, training pants, feminine hygiene products such as sanitary napkins and tampons, adult incontinence pads, underwear, or briefs, and pet training pads. Other examples include a variety of different dry or wet wipes, including those for consumer (such as personal care or household) and industrial (such as food service, health care, or specialty) use. Nonwoven webs can also be used as padding for pillows, mattresses, and upholstery, and batting for quilts and comforters. In the medical and industrial fields, nonwoven webs of the present invention may be used for consumer, medical, and industrial face masks, protective clothing, caps, and shoe covers, disposable sheets, surgical gowns, drapes, bandages, and medical dressings.
Additionally, nonwoven webs as described herein may be used for environmental fabrics such as geotextiles and tarps, oil and chemical absorbent pads, as well as building materials such as acoustic or thermal insulation, tents, lumber and soil covers and sheeting. Nonwoven webs may also be used for other consumer end use applications, such as for, carpet backing, packaging for consumer, industrial, and agricultural goods, thermal or acoustic insulation, and in various types of apparel.
The dry laid nonwoven webs as described herein may also be used for a variety of filtration applications, including transportation (e.g., automotive or aeronautical), commercial, residential, industrial, or other specialty applications. Examples can include filter elements for consumer or industrial air or liquid filters (e.g., gasoline, oil, water), including nanofiber webs used for microfiltration, as well as end uses like tea bags, coffee filters, and dryer sheets. Further, nonwoven webs as described herein may be used to form a variety of components for use in automobiles, including, but not limited to, brake pads, trunk liners, carpet tufting, and under padding.
The textiles can include single type or multiple type of natural fibers and/or single type or multiple type of synthetic fibers. Examples of textile fiber combinations include all natural, all synthetic, two or more type of natural fibers, two or more types of synthetic fibers, one type of natural fiber and one type of synthetic fiber, one type of natural fibers and two or more types of synthetic fibers, two or more types of natural fibers and one type of synthetic fibers, and two or more types of natural fibers and two or more types of synthetic fibers.
Natural fibers include those that are plant derived or animal derived. Natural fibers can be cellulosics, hemicellulosics, and lignins. Examples of plant derived natural fibers include hardwood pulp, softwood pulp, and wood flour; and other plant fibers including those in wheat straw, rice straw, abaca, coir, cotton, flax, hemp, jute, bagasse, kapok, papyrus, ramie, rattan, vine, kenaf, abaca, henequen, sisal, soy, cereal straw, bamboo, reeds, esparto grass, bagasse, Sabai grass, milkweed floss fibers, pineapple leaf fibers, switch grass, lignin-containing plants, and the like. Examples of animal derived fibers include wool, silk, mohair, cashmere, goat hair, horsehair, avian fibers, camel hair, angora wool, and alpaca wool.
Synthetic fibers are those fibers that are, at least in part, synthesized or derivatized through chemical reactions, or regenerated, and include, but are not limited to, rayon, viscose, mercerized fibers or other types of regenerated cellulose (conversion of natural cellulose to a soluble cellulosic derivative and subsequent regeneration) such as lyocell (also known as TENCEL™), Cupro, Modal, acetates such as polyvinyl acetate, polyamides including nylon, polyesters such as PET, olefinic polymers such as polypropylene and polyethylene, polycarbonates, poly sulfates, poly sulfones, polyethers such as polyether-urea known as Spandex or elastane, polyacrylates, acrylonitrile copolymers, polyvinylchloride (PVC), polylactic acid, polyglycolic acid, sulfopolyester fibers, and combinations thereof.
Prior to entering the chemical recycling facility, the textiles can be size reduced via chopping, shredding, harrowing, confrication, pulverizing, or cutting to make size reduced textiles. The textiles can also be densified (e.g., pelletized) prior to entering the chemical recycling facility. Examples of processes that densify include extrusion (e.g., into pellets), molding (e.g., into briquettes), and agglomerating (e.g., through externally applied heat, heat generated by frictional forces, or by adding one or more adherents, which can be non-virgin polymers themselves). Alternatively, or in addition, the textiles can be in any of the forms mentioned herein and may be exposed to one or more of the previously mentioned steps in the pre-processing facility 20 prior to being processed in the remaining facilities of the chemical recycling facility 10 shown in
In an embodiment or in combination with any embodiment mentioned herein, polyethylene terephthalate (PET) and one or more polyolefins (PO) in combination make up at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent of the waste plastic (e.g., MPW) fed to the chemical recycling facility in stream 100 of
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic can comprise at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent of PET, based on the total weight of the plastic in the waste plastic introduced into the chemical recycling facility 10.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic can comprise at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40 and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, or not more than 35 weight percent PO, based on the total weight of the plastic in the waste plastic, or PO can be present in an amount in the range of from 5 to 75 weight percent, 10 to 60 weight percent, or 20 to 35 weight percent, based on the total weight of plastic in the waste plastic introduced into the chemical recycling facility 10.
The waste plastic (e.g., MPW) introduced into the chemical recycling facility may be provided from a variety of sources, including, but not limited to, municipal recycling facilities (MRFs) or reclaimer facilities or other mechanical or chemical sorting or separation facilities, manufacturers or mills or commercial production facilities or retailers or dealers or wholesalers in possession of post-industrial and pre-consumer recyclables, directly from households/businesses (i.e., unprocessed recyclables), landfills, collection centers, convenience centers, or on docks or ships or warehouses thereon. In an embodiment or in combination with any embodiment mentioned herein, the source of waste plastic (e.g. MPW) does not include deposit state return facilities, whereby consumers can deposit specific recyclable articles (e.g., plastic containers, bottles, etc.) to receive a monetary refund from the state. In an embodiment or in combination with any embodiment mentioned herein, the source of waste plastic (e.g. MPW) does include deposit state return facilities, whereby consumers can deposit specific recyclable articles (e.g., plastic containers, bottles, etc.) to receive a monetary refund from the state. Such return facilities are commonly found, for example, in grocery stores.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic may be provided as a waste stream from another processing facility, for example a municipal recycling facility (MRF) or reclaimer facility, or as a plastic-containing mixture comprising waste plastic sorted by a consumer and left for collection at a curbside, or at a central convenience station. In one or more of such embodiments, the waste plastic comprises one or more MRF products or co-products, reclaimer co-products, sorted plastic-containing mixtures, and/or PET-containing waste plastic from a plastic article manufacturing facility comprising at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 weight percent PET and/or not more than 99.9, not more than 99, not more than 98, not more than 97, not more than 96, or not more than 95 weight percent PET, on a dry plastics basis, or it can be in the range of from 10 to 99.9 weight percent, 20 to 99 weight percent, 30 to 95 weight percent, or 40 to 90 weight percent PET, on a dry plastics basis.
In one or more of such embodiments, the waste plastic comprises a quantity of a PET-containing reclaimer coproduct or plastic-containing mixture comprising at least 1, at least 10, at least 30, at least 50, at least 60, at least 70, at least 80, or at least 90 weight percent and/or not more than 99.9, not more than 99, or not more than 90 weight percent PET, on a dry plastic basis, or it can be in the range of from 1 to 99.9 weight percent, 1 to 99 weight percent, or 10 to 90 weight percent PET, on a dry plastic basis. Reclaimer facilities may also include processes that produce high purity PET (at least 99 or at least 99.9 weight percent) reclaimer co-products but in a form that is undesirable to mechanical recycling facilities. As used herein, the term “reclaimer co-product” refers to any material separated or recovered by the reclaimer facility that is not recovered as a clear rPET product, including colored rPET. The reclaimer co-products described above and below are generally considered to be waste products and may sent to landfills.
In one or more of such embodiments, the waste plastic comprises a quantity of reclaimer wet fines comprising at least 20, at least 40, at least 60, at least 80, at least 90, at least 95, or at least 99 weight percent and/or not more than 99.9 weight percent PET, on a dry plastic basis. In one or more of such embodiments, the waste plastic comprises a quantity of colored plastic-containing mixture comprising at least 1, at least 10, at least 20, at least 40, at least 60, at least 80, or at least 90 and/or not more than 99.9 or not more than 99 weight percent PET, on a dry plastic basis. In one or more of such embodiments, the waste plastic comprises a quantity of eddy current waste stream comprising metal and at least 0.1, at least 1, at least 10, at least 20, at least 40, at least 60, or at least 80 weight percent and/or not more than 99.9, not more than 99, or not more than 98 weight percent PET, on a dry plastic basis. In one or more of such embodiments, the waste plastic comprises a quantity of reclaimer flake reject comprising at least 0.1, at least 1, at least 10, at least 20, at least 40, at least 60, or at least 80 weight percent and/or not more than 99.9, not more than 99, or not more than 98 weight percent PET, on a dry plastic basis, or it could be in the range of from 0.1 to 99.9 weight percent, 1 to 99 weight percent, or 10 to 98 weight percent PET, on a dry plastic basis. In one or more of such embodiments, the waste plastic comprises a quantity of dry fines comprising at least 50, at least 60, at least 70, at least 80, at least 90, at least 95, at least 99, at least 99.9 weight percent PET, on a dry plastic basis.
The chemical recycling facility 10 may also include infrastructure for receiving waste plastic (e.g., MPW) as described herein to facilitate delivery of the waste plastic by any suitable type of vehicle including, for example, trains, trucks, and/or ships. Such infrastructure may include facilities to assist with offloading the waste plastic from the vehicle, as well as storage facilities and one or more conveyance systems for transporting the waste plastic from the offloading zone to the downstream processing zones. Such conveyance systems may include, for example, pneumatic conveyors, belt conveyors, bucket conveyors, vibrating conveyors, screw conveyors, cart-on-track conveyors, tow conveyors, trolley conveyors, front-end loaders, trucks, and chain conveyors.
The waste (e.g., MPW) introduced into the chemical recycling facility 10 may be in several forms including, but not limited to, whole articles, particulates (e.g., comminuted, pelletized, fiber plastic particulates), bound bales (e.g., whole articles compressed and strapped), unbound articles (i.e., not in bales or packaged), containers (e.g., box, sack, trailer, railroad car, loader bucket), piles (e.g., on a concrete slab in a building), solid/liquid slurries (e.g., pumped slurry of plastics in water), and/or loose materials conveyed physically (e.g., particulates on a conveyor belt) or pneumatically (e.g., particulates mixed with air and/or inert gas in a convey pipe).
As used herein, the term “waste plastic particulates” refers to waste plastic having a D90 of less than 1 inch. In an embodiment or in combination with any embodiment mentioned herein, the waste plastic particulates can be MPW particulates. A waste plastic or MPW particulate can include, for example, comminuted plastic particles that have been shredded or chopped, or plastic pellets. When whole or nearly whole articles are introduced into the chemical recycling facility 10 (or preprocessing facility 20), one or more comminuting or pelletizing steps may be used therein to form waste plastic particulates (e.g., MPW particulates). Alternatively, or in addition, at least a portion of the waste plastic introduced into the chemical recycling facility 10 (or preprocessing facility 20) may already be in the form of particulates.
The general configuration and operation of each of the facilities that may be present in the chemical recycling facility shown in
As shown in
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic (e.g., MPW) may be provided in bales of unsorted or presorted plastic, or in other large, aggregated forms. The bales or aggregated plastics undergo an initial process in which they are broken apart. Plastic bales can be sent to a debaler machine that comprises, for example, one or more rotating shafts equipped with teeth or blades configured to break the bales apart, and in some instances shred, the plastics from which the bales are comprised. In one or more other embodiments, the bales or aggregated plastics can be sent to a guillotine machine where they are chopped into smaller sized pieces of plastic. The debaled and/or guillotined plastic solids can then be subjected to a sorting process in which various non-plastic, heavy materials, such as glass, metal, and rocks, are removed. This sorting process can be performed manually or by a machine. Sorting machines may rely upon optical sensors, magnets, eddy currents, pneumatic lifts or conveyors that separate based on drag coefficient, or sieves to identify and remove the heavy materials.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic feedstock comprises plastic solids having a D90 that is greater than one inch, greater than 0.75 inch, or greater than 0.5 inch, such as used containers. Alternatively, or in addition, the waste plastic feedstock may also comprise a plurality of plastic solids that, at one time, had at least one dimension of greater than one inch, but the solids may have been compacted, pressed, or otherwise aggregated into a larger unit, such as a bale. In such embodiments wherein at least a portion, or all, of the plastic solids have at least one dimension greater than one inch, greater than 0.75 inch, or 0.5 inch, the feedstock may be subjected to a mechanical size reduction operation, such as grinding/granulating, shredding, guillotining, chopping, or other comminuting process to provide MPW particles having a reduced size. Such mechanical size reduction operations can include a size reduction step other than crushing, compacting, or forming plastic into bales.
In one or more other embodiments, the waste plastic may already have undergone some initial separation and/or size-reduction process. In particular, the waste plastic may be in the form of particles or flakes and provided in some kind of container, such as a sack or box. Depending upon the composition of these plastic solids and what kind of preprocessing they may have been subjected to, the plastic feedstock may bypass the debaler, guillotine, and/or heavies removal station and proceed directly to the granulating equipment for further size reduction.
In an embodiment or in combination with any embodiment mentioned herein, the debaled or broken apart plastic solids may be sent to comminution or granulating equipment in which the plastic solids are ground, shredded, or otherwise reduced in size. The plastic materials can be made into particles having a D90 particle size of less than 1 inch, less than ¾ inch, or less than ½ inch. In one or more other embodiments, the D90 particle size of the plastic materials exiting the granulating equipment is from 1/16 inch to 1 inch, ⅛ inch to ¾ inch, ¼ inch to ⅝ inch, or ⅜ inch to ½ inch.
In an embodiment or in combination with any embodiment mentioned herein, the unprocessed or partially processed waste plastic provided to the chemical recycling facility may comprise various organic contaminants or residues that may be associated with the previous use of the waste plastic. For example, the waste plastic may comprise food or beverage soils, especially if the plastic material was used in food or beverage packaging. Accordingly, the waste plastic may also contain microorganism contaminants and/or compounds produced by the microorganisms. Exemplary microorganisms that may be present on the surfaces of the plastic solids making up the waste plastic include E. coli, salmonella, C. dificile, S. aureus, L. monocytogenes, S. epidermidis, P. aeruginosa, and P. fluorescens.
Various microorganisms can produce compounds that cause malodors. Exemplary odor-causing compounds include hydrogen sulfide, dimethyl sulfide, methanethiol, putrescine, cadaverine, trimethylamine, ammonia, acetaldehyde, acetic acid, propanoic acid, and/or butyric acid. Thus, it can be appreciated that the waste plastic could present odor nuisance concerns. Therefore, the waste plastic may be stored within an enclosed space, such as a shipping container, enclosed railcar, or enclosed trailer until it can be processed further. In certain embodiments, the unprocessed or partially processed waste plastic, once it reaches the site where processing (e.g., comminuting, washing, and sorting) of the waste plastic is to occur, can be stored with the enclosed spaces for no more than one week, no more than 5 days, no more than 3 days, no more than 2 days, or no more than 1 day.
In an embodiment or in combination with any embodiment mentioned herein, the preprocessing facility 20 may also include equipment for or the step of treating the waste plastic with a chemical composition that possesses antimicrobial characteristics, thereby forming treated particulate plastic solids. In some embodiments, this may include treating the waste plastic with sodium hydroxide, high pH salt solutions (e.g., potassium carbonate), or other antimicrobial composition.
Additionally, in an embodiment or in combination with any embodiment mentioned herein, the waste plastic (e.g., MPW) may optionally be washed to remove inorganic, non-plastic solids such as dirt, glass, fillers and other non-plastic solid materials, and/or to remove biological components such as bacteria and/or food. The resulting washed waste plastic may also be dried to a moisture content of not more than 5, not more than 3, not more than 2, not more than 1, not more than 0.5, or not more than 0.25 weight percent water (or liquid), based on the total weight of the waste plastic. The drying can be done in any suitable manner, including by the addition of heat and/or air flow, mechanical drying (e.g., centrifugal), or by permitting evaporation of the liquid to occur over a specified time.
In an embodiment or in combination with any embodiment mentioned herein, the preprocessing facility 20 or step of the chemical recycling process or facility 10 may include at least one separation step or zone. The separation step or zone may be configured to separate the waste plastic stream into two or more streams enriched in certain types of plastics. Such separation is particularly advantageous when the waste plastic fed to the preprocessing facility 20 is MPW.
In an embodiment or in combination with any embodiment mentioned herein, the separation zone 22 (see
When the enriched or depleted component is a solid, concentrations are on an undiluted dry solids weight basis; when the enriched or depleted component is a liquid, concentrations are on an undiluted dry liquid weight basis; and when the enriched or depleted component is a gas, concentrations are on an undiluted dry gas weight basis. In addition, enriched and depleted can be expressed in mass balance terms, rather than as a concentration. As such, a stream enriched in a specific component can have a mass of the component that is greater than the mass of the component in a reference stream (e.g., feed stream or other product stream), while a stream depleted in a specific component can have a mass of the component that is less than the mass of the component in a reference stream (e.g., feed stream or other product stream).
Referring again to
In an embodiment or in combination with any embodiment mentioned herein, when a MPW stream 100 is fed to the preprocessing facility 20 (or separation zone 22), the PET-enriched stream may be enriched in concentration or mass of PET relative to the concentration or mass of PET in the MPW stream, or the PET-depleted stream, or both, on an undiluted solids dry weight basis. For example, if the PET-enriched stream is diluted with liquid or other solids after separation, the enrichment would be on the basis of a concentration in the undiluted PET-enriched stream, and on a dry basis. In one embodiment or in combination with any of the mentioned embodiments, the PET-enriched stream 112 has a percent PET enrichment relative to the MPW feed stream (Feed-Based % PET Enrichment), the PET-depleted product stream 114 (Product-Based % PET Enrichment), or both that is at least 10, at least 20, at least 40, at least 50, at least 60, at least 80, at least 100, at least 125, at least 150, at least 175, at least 200, at least 225, at least 250, at least 300, at least 350, at least 400, at least 500, at least 600, at least 700, at least 800, at least 900, or at least 1000% as determined by the formula:
where PETe is the concentration of PET in the PET-enriched product stream 112 on an undiluted dry weight basis;
PETm is the concentration of PET in the MPW feed stream 100 on a dry weight basis; and
PETd is the concentration of PET in the PET-depleted product stream 114 on a dry weight basis.
In an embodiment or in combination with any embodiment mentioned herein, when a stream comprising MPW 100 is fed to the preprocessing facility 20 (or separation zone 22), the PET-enriched stream is also enriched in halogens, such as fluorine (F), chlorine (CI), bromine (Br), iodine (I), and astatine (At), and/or halogen-containing compounds, such as PVC, relative to the concentration or mass of halogens in the MPW feed stream 100, or the PET-depleted product stream 114, or both. In one embodiment or in combination with any of the mentioned embodiments, the PET-enriched stream 112 has a percent PVC enrichment relative to the MPW feed stream 100 (Feed-Based % PVC Enrichment), the PET-depleted product stream (Product-Based % PVC Enrichment), or both that is at least 1, at least 3, at least 5, at least 7, at least 10, at least 15, at least 20, at least 40, at least 50, at least 60, at least 80, at least 100, at least 125, at least 150, at least 175, at least 200, at least 225, at least 250, at least 300, at least 350, at least 400, or at least 500% as determined by the formula:
where PVCe is the concentration of PVC in the PET-enriched product stream 112 on an undiluted dry weight basis;
PVCm is the concentration of PVC in the MPW feed stream 100 on an undiluted dry weight basis; and
where PVCd is the concentration of PVC in the PET-depleted product stream 114 on an undiluted dry weight basis.
In one embodiment or in combination with any of the mentioned embodiments, when a MPW stream 100 is fed to the preprocessing facility 20 (or separation zone 22), the PET-depleted stream 114 is enriched in polyolefins relative to the concentration or mass of polyolefins in the MPW feed stream 100, the PET-enriched product stream 112, or both, on an undiluted solids dry basis. In one embodiment or in combination with any of the mentioned embodiments, the PET-depleted stream 114 has a percent polyolefin enrichment relative to the MPW feed stream 100 (Feed-Based % PO Enrichment), or relative to the PET-enriched product stream 112 (Product-Based % PO Enrichment), or both that is at least 10, at least 20, at least 40, at least 50, at least 60, at least 80, at least 100, at least 125, at least 150, at least 175, at least 200, at least 225, at least 250, at least 300, at least 350, at least 400, at least 500, at least 600, at least 700, at least 800, at least 900, or at least 1000% as determined by the formula:
where POd is the concentration of polyolefins in the PET-depleted product stream 114 on an undiluted dry weight basis;
POm is the concentration of PO in the MPW feed stream 100 on a dry weight basis; and
POe is the concentration of PO in the PET-enriched product stream 112 on a dry weight basis.
In one embodiment or in combination with any other embodiments, when a MPW stream 100 is fed to the preprocessing facility 20 (or separation zone 22), the PET-depleted stream 114 is also depleted in halogens, such as fluorine (F), chlorine (CI), bromine (Br), iodine (I), and astatine (At), and/or halogen-containing compounds, such as PVC, relative to the concentration or mass of halogens in the MPW stream 100, the PET-enriched stream 112, or both. In one embodiment or in combination with any of the mentioned embodiments, the PET-depleted stream 114 has a percent PVC depletion, relative to the MPW feed stream 100 (Feed-Based % PVC Depletion) or the PET-enriched product stream 112 (Product-Based % PVC Depletion) that is at least 1, at least 3, at least 5, at least 7, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 50, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, or at least 90% as determined by the formula:
where PVCm is the concentration of PVC in the MPW feed stream 100 on an undiluted dry weight basis;
PVCd is the concentration of PVC in the PET-depleted product stream 114 on an undiluted dry weight basis; and
PVCe is the concentration of PVC in the PET-enriched product stream 112 on an undiluted dry weight basis.
The PET-depleted stream 114 is depleted in PET relative to the concentration or mass of PET in the MPW stream 100, the PET-enriched stream 112, or both. In one embodiment or in combination with any of the mentioned embodiments, the PET-depleted stream 114 has a percent PET depletion, relative to the MPW feed stream 100 (Feed-Base % PET Depletion) or the PET-enriched product stream 112 (Product-Based % PET Depletion) that is at least 1, at least 3, at least 5, at least 7, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 50, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, or at least 90% as determined by the formula:
where PETm is the concentration of PET in the MPW feed stream 100 on an undiluted dry weight basis;
PETd is the concentration of PET in the PET-depleted product stream 114 on an undiluted dry weight basis; and
PETe is the concentration of PET in the PET-enriched product stream 112 on an undiluted dry weight basis.
The percentage enrichment or depletion in any of the above embodiments can be an average over 1 week, or over 3 days, or over 1 day, and the measurements can be conducted to reasonably correlate the samples taken at the exits of the process to MPW bulk from which the sample of MPW is taking into account the residence time of the MPW to flow from entry to exit. For example, if the average residence time of the MPW is 2 minutes, then the outlet sample would be taken two minutes after the input sample, so that the samples correlate to one another.
In an embodiment or in combination with any embodiment mentioned herein, the PET-enriched stream exiting the separation zone 22 or the preprocessing facility 20 may include at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, at least 97, at least 99, at least 99.5, or at least 99.9 weight percent PET, based on the total weight of plastic in the PET-enriched stream 112. The PET-enriched stream 112 may also be enriched in PVC and can include, for example, at least 0.1, at least 0.5, at least 1, at least 2, at least 3, at least 5 and/or not more than 10, not more than 8, not more than 6, not more than 5, not more than 3 weight percent of halogens, including PVC, based on the total weight of plastic in the PET-enriched stream, or it can be in the range of 0.1 to 10 weight percent, 0.5 to 8 weight percent, or 1 to 5 weight percent, based on the total weight of plastic in the PET-enriched stream. The PET-enriched stream may include at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, at least 99, or at least 99.5 weight percent of the total amount of PET introduced into the preprocessing facility 20 (or separation zone 22).
The PET-enriched stream 112 may also be depleted in PO and/or heavier plastics such as polytetrafluoroethylene (PTFE), polyamide (PA 12, PA 46, PA 66), polyacrylamide (PARA), polyhydroxybutyrate (PHB), polycarbonate polybutylene terephthalate blends (PC/PBT), polyvinyl chloride (PVC), polyimide (PI), polycarbonate (PC), polyethersulfone (PESU), polyether ether ketone (PEEK), polyamide imide (PAI), polyethylenimine (PEI), polysulfone (PSU), polyoxymethylene (POM), polyglycolides (poly(glycolic acid), PGA), polyphenylene sulfide (PPS), thermoplastic styrenic elastomers (TPS), amorphous thermoplastic polyimide (TPI), liquid crystal polymer (LCP), glass fiber-reinforced PET, chlorinated polyvinyl chloride (CPVC), polybutylene terephthalate (PBT), polyphthalamide (PPA), polyvinylidene chloride (PVDC), ethylene tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), fluorinated ethylene propylene (FEP), polymonochlorotrifluoroethylene (PCTFE), and perfluoroalkoxy (PFA), any of which may include carbon, glass, and/or mineral fillers, and which have a density higher than PET and PVC.
In an embodiment or in combination with any embodiment mentioned herein, the PET-enriched stream 112 may comprise not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, not more than 1, not more than 0.5 weight percent PO, based on the total weight of plastic in the PET-enriched stream 112. The PET-enriched stream 112 may comprise not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent of the total amount of PO introduced into the preprocessing facility 20 (or separation zone 22). The PET-enriched stream 112 may comprise not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, not more than 1 weight percent of components other than PET, based on the total weight of the PET-enriched stream 112.
Additionally, or in the alternative, the PET-enriched stream 112 can include not more than 2, not more than 1, not more than 0.5, or not more than 0.1 weight percent of adhesives on a dry basis. Typical adhesives include carpet glue, latex, styrene butadiene rubber, and the like. Additionally, the PET-enriched stream 112 can include not more than 4, not more than 3, not more than 2, not more than 1, not more than 0.5, or not more than 0.1 weight percent plastic fillers and solid additives on a dry basis. Exemplary fillers and additives include silicon dioxide, calcium carbonate, talc, silica, glass, glass beads, alumina, and other solid inerts, which do not chemically react with the plastics or other components in the processes described herein.
In an embodiment or in combination with any embodiment mentioned herein, the PET-depleted (or PO-enriched) stream 114 exiting the separation zone 22 or the preprocessing facility 20 may include at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, at least 97, at least 99, or at least 99.5 weight percent PO, based on the total weight of plastic in the PET-depleted (or PO-enriched) stream 114. The PET-depleted (or PO-enriched stream) may be depleted in PVC and can include, for example, not more than 5, not more than 2, not more than 1, not more than 0.5, not more than 0.1, not more than 0.05, or not more than 0.01 weight percent of halogens, including chorine in PVC, based on the total weight of plastic in the PET-depleted (or PO-enriched) stream. The PET-depleted or PO-enriched stream may include at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, at least 99, or at least 99.9 weight percent of the total amount of PO introduced into the preprocessing facility 20 or separation facility 22.
The PO-enriched stream 114 may also be depleted in PET and/or other plastics, including PVC. In an embodiment or in combination with any embodiment mentioned herein, the PET-depleted (or PO-enriched stream) may comprise not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, not more than 1, not more than 0.5 weight percent PET, based on the total weight of plastic in the PET-depleted or PO-enriched stream. The PO-enriched (or PET-depleted) stream 114 may comprise not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent of the total amount of PET introduced into the preprocessing facility.
In an embodiment or in combination with any embodiment mentioned herein, the PET-depleted or PO-enriched stream 114 may also comprise not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, not more than 1 weight percent of components other than PO, based on the total weight of PET-depleted or PO-enriched stream 114. The PET-depleted or PO-enriched stream 114 comprises not more than 4, not more than 2, not more than 1, not more than 0.5, or not more than 0.1 weight percent of adhesives, based on the total weight of the stream.
In an embodiment or in combination with any embodiment mentioned herein, the PET-depleted or PO-enriched stream 114 may have a melt viscosity of at least 1, at least 5, at least 50, at least 100, at least 200, at least 300, at least 400, at least 500, at least 600, at least 700, at least 800, at least 900, at least 1000, at least 1500, at least 2000, at least 2500, at least 3000, at least 3500, at least 4000, at least 4500, at least 5000, at least 5500, at least 6000, at least 6500, at least 7000, at least 7500, at least 8000, at least 8500, at least 9000, at least 9500, or at least 10,000 poise, measured using a Brookfield R/S rheometer with V80-40 vane spindle operating at a shear rate of 10 rad/s and a temperature of 350° C. Alternatively, or in addition, the PET-depleted or PO-enriched stream may have a melt viscosity of not more than 25,000, not more than 24,000, not more than 23,000, not more than 22,000, not more than 21,000, not more than 20,000, not more than 19,000, not more than 18,000, or not more than 17,000 poise, (measured at 10 rad/s and 350° C.). Or the stream may have a melt viscosity in the range of from 1 to 25,000 poise, 500 to 22,000 poise, or 1000 to 17,000 poise (measured at 10 rad/s and 350° C.).
Any suitable type of separation device, system, or facility may be employed to separate the waste plastic into two or more streams enriched in certain types of plastics such as, for example, the PET-enriched stream 112 and the PO-enriched stream 114. Examples of suitable types of separation include mechanical separation and density separation, which may include sink-float separation and/or centrifugal density separation. As used herein, the term “sink-float separation” refers to a density separation process where the separation of materials is primarily caused by floating or sinking in a selected liquid medium, while the term “centrifugal density separation” refers to a density separation process where the separation of materials is primarily caused by centrifugal forces. In general, the term “density separation process” refers to a process for separating materials based, at least in part, upon the respective densities of the materials into at least a higher-density output and a lower-density output and includes both sink-float separation and centrifugal density separation.
When sink-float separation is used, the liquid medium can comprise water. Salts, saccharides, and/or other additives can be added to the liquid medium, for example to increase the density of the liquid medium and adjust the target separation density of the sink-float separation stage. The liquid medium can comprise a concentrated salt solution. In one or more such embodiments, the salt is sodium chloride. In one or more other embodiments, however, the salt is a non-halogenated salt, such as acetates, carbonates, citrates, nitrates, nitrites, phosphates, and/or sulfates. The liquid medium can comprise a concentrated salt solution comprising sodium bromide, sodium dihydrogen phosphate, sodium hydroxide, sodium iodide, sodium nitrate, sodium thiosulfate, potassium acetate, potassium bromide, potassium carbonate, potassium hydroxide, potassium iodide, calcium chloride, cesium chloride, iron chloride, strontium chloride, zinc chloride, manganese sulfate, magnesium sulfate, zinc sulfate, and/or silver nitrate. In an embodiment or in combination with any embodiment mentioned herein, the salt is a caustic component. The salt may comprise sodium hydroxide, potassium hydroxide, and/or potassium carbonate. The concentrated salt solution may have a pH of greater than 7, greater than 8, greater than 9, or greater than 10.
In an embodiment or in combination with any embodiment mentioned herein, the liquid medium can comprise a saccharide, such as sucrose. The liquid medium can comprise carbon tetrachloride, chloroform, dichlorobenzene, dimethyl sulfate, and/or trichloro ethylene. The particular components and concentrations of the liquid medium may be selected depending on the desired target separation density of the separation stage. The centrifugal density separation process may also utilize a liquid medium as described above to improve separation efficiency at the target separation density.
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic separation methods comprise at least two density separation stages. In certain such embodiments, the methods generally comprise introducing waste plastic particulates into the first density separation stage and feeding an output from the first density separation stage into the second density separation stage. The density separation stages can be any system or unit operation that performs a density separation process, as defined herein. At least one of the density separation stages comprises a centrifugal force separation stage or a sink-float separation stage. Each of the first and second density separation stages comprises a centrifugal force separation stage and/or a sink-float separation stage.
To produce a PET-enriched material stream, one of the density separation stages may comprise a low-density separation stage and the other generally comprises a high-density separation stage. As defined herein, the low-density separation stage has a target separation density less than the target separation density of the high-density separation stage. The low-density separation stage has a target separation density less than the density of PET, and the high-density separation stage has a target separation density greater than the density of PET.
As used herein, the term “target separation density” refers to a density above which materials subjected to a density separation process are preferentially separated into the higher-density output and below which materials are separated in the lower-density output. The target separation density specifies a density value, wherein it is intended that all plastics and other solid materials having a density higher than the value are separated into the higher-density output and all plastics and other solid materials having a density lower than the value are separated into the lower-density output. However, the actual separation efficiency of the materials in a density separation process may depend on various factors, including residence time and relative closeness of the density of a particular material to the target density separation value, as well as factors related to the form of the particulate such as, for example, area-to-mass ratio, degree of sphericity, and porosity.
In an embodiment or in combination with any embodiment mentioned herein, the low-density separation stage has a target separation density that is less than 1.35, less than 1.34, less than 1.33, less than 1.32, less than 1.31, or less than 1.30 g/cc and/or at least 1.25, at least 1.26, at least 1.27, at least 1.28, or at least 1.29 g/cc. The high-density separation stage has a target separation density that is at least 0.01, at least 0.025, at least 0.05, at least 0.075, at least 0.1, at least 0.15, or at least 0.2 g/cc greater than the target separation density of the low-density separation stage. The target separation density of the high-density separation stage is at least 1.31, at least 1.32, at least 1.33, at least 1.34, at least 1.35, at least 1.36, at least 1.37, at least 1.38, at least 1.39, or at least 1.40 g/cc and/or not more than 1.45, not more than 1.44, not more than 1.43, not more than 1.42, or not more than 1.41 g/cc. The target separation density of the low-density separation stage is in the range of 1.25 to 1.35 g/cc and the target separation density of said high-density separation stage is in the range of 1.35 to 1.45 g/cc.
Referring again to
As shown in
When added to the liquification zone 40, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent of the plastic (usually waste plastic) undergoes a reduction in viscosity. In some cases, the reduction in viscosity can be facilitated by heating (e.g., addition of steam directly or indirectly contacting the plastic), while, in other cases, it can be facilitated by combining the plastic with a solvent capable of dissolving it. Examples of suitable solvents can include, but are not limited to, alcohols such as methanol or ethanol, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, cyclohexanedimethanol, glycerin, pyrolysis oil, motor oil, and water. As shown in
In an embodiment or in combination with any embodiment mentioned herein, the solvent can comprise a stream withdrawn from one or more other facilities within the chemical recycling facility. For example, the solvent can comprise a stream withdrawn from at least one of the solvolysis facility 30, the pyrolysis facility 60, and the cracking facility 70. The solvent can be or comprise at least one of the solvolysis coproducts described herein or can be or comprise pyrolysis oil.
In some cases, the plastic can be depolymerized such that, for example, the number average chain length of the plastic is reduced by contact with a depolymerization agent. In an embodiment or in combination with any embodiment mentioned herein, at least one of the previously-listed solvents may be used as a depolymerization agent, while, in one or more other embodiments, the depolymerization agent can include an organic acid (e.g., acetic acid, citric acid, butyric acid, formic acid, lactic acid, oleic acid, oxalic, stearic acid, tartaric acid, and/or uric acid) or inorganic acid such as sulfuric acid (for polyolefin). The depolymerization agent may reduce the melting point and/or viscosity of the polymer by reducing its number average chain length.
Alternatively, or additionally, a plasticizer can be used in the liquification zone to reduce the viscosity of the plastic. Plasticizers for polyethylene include, for example, dioctyl phthalate, dioctyl terephthalate, glyceryl tribenzoate, polyethylene glycol having molecular weight of up to 8,000 Daltons, sunflower oil, paraffin wax having molecular weight from 400 to 1,000 Daltons, paraffinic oil, mineral oil, glycerin, EPDM, and EVA. Plasticizers for polypropylene include, for example, dioctyl sebacate, paraffinic oil, isooctyl tallate, plasticizing oil (Drakeol 34), naphthenic and aromatic processing oils, and glycerin. Plasticizers for polyesters include, for example, polyalkylene ethers (e.g., polyethylene glycol, polytetramethylene glycol, polypropylene glycol or their mixtures) having molecular weight in the range from 400 to 1500 Daltons, glyceryl monostearate, octyl epoxy soyate, epoxidized soybean oil, epoxy tallate, epoxidized linseed oil, polyhydroxyalkanoate, glycols (e.g., ethylene glycol, pentamethylene glycol, hexamethylene glycol, etc.), phthalates, terephthalates, trimellitate, and polyethylene glycol di-(2-ethylhexoate). When used, the plasticizer may be present in an amount of at least 0.1, at least 0.5, at least 1, at least 2, or at least 5 weight percent and/or not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent, based on the total weight of the stream, or it can be in a range of from 0.1 to 10 weight percent, 0.5 to 8 weight percent, or 1 to 5 weight percent, based on the total weight of the stream.
Further, one or more of the methods of liquifying the waste plastic stream can also include adding at least one blending agent to the plastic before, during, or after the liquification process. Such blending agents may include for example, emulsifiers and/or surfactants, and may serve to more fully blend the liquified plastic into a single phase, particularly when differences in densities between the plastic components of a mixed plastic stream result in multiple liquid or semi-liquid phases. When used, the blending agent may be present in an amount of at least 0.1, at least 0.5, at least 1, at least 2, or at least 5 weight percent and/or not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent, based on the total weight of the stream, or it can be in a range of from 0.1 to 10 weight percent, 0.5 to 8 weight percent, or 1 to 5 weight percent, based on the total weight of the stream.
When combined with the PO-enriched plastic stream 114 as generally shown in
Additionally, as shown in
In an embodiment or in combination with any embodiment mentioned herein, the feed stream to one or more of the downstream chemical recycling facilities from the liquification zone 40 can comprise at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent of one or more solvolysis coproduct streams, based on the total weight of the feed stream introduced into the downstream processing facility or facilities. For example, the feed streams 116, 118, 120, and 122 to each of the POX facility 50, the pyrolysis facility 60, the cracking facility 70, the energy recovery facility 80, and/or any other facility 90 of the chemical recycling facility 10 may include PO-enriched waste plastic and an amount of one or more solvolysis coproducts described herein.
Additionally, or in the alternative, the feed stream to the pyrolysis facility 60, the POX facility 50, the cracking facility 70, the energy recovery facility 80, and/or any other facility 90 can comprise not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent of one or more solvolysis coproduct streams, based on the total weight of the feed stream introduced into the downstream processing facility or facilities.
Alternatively, or in addition, the liquified (or reduced viscosity) plastic stream withdrawn from the liquification zone 40 can include at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent of PO, based on the total weight of the stream, or the amount of PO can be in the range of from 1 to 95 weight percent, 5 to 90 weight percent, or 10 to 85 weight percent, based on the total weight of the stream.
In an embodiment or in combination with any embodiment mentioned herein, the liquified plastic stream exiting the liquification zone 40 can have a viscosity of less than 3,000, less than 2,500, less than 2,000, less than 1,500, less than 1,000, less than 800, less than 750, less than 700, less than 650, less than 600, less than 550, less than 500, less than 450, less than 400, less than 350, less than 300, less than 250, less than 150, less than 100, less than 75, less than 50, less than 25, less than 10, less than 5, or less than 1 poise, measured using a Brookfield R/S rheometer with V80-40 vane spindle operating at a shear rate of 10 rad/s and a temperature of 350° C. In an embodiment or in combination with any embodiment mentioned herein, the viscosity (measured at 350° C. and 10 rad/s and expressed in poise) of the liquified plastic stream exiting the liquification zone is not more than 95, not more than 90, not more than 75, not more than 50, not more than 25, not more than 10, not more than 5, or not more than 1 percent of the viscosity of the PO-enriched stream introduced into the liquification zone.
As shown in
In an embodiment or in combination with any embodiment mentioned herein, and as shown in
In an embodiment or in combination with any embodiment mentioned herein (not shown in
As shown in
In an embodiment or in combination with any embodiment mentioned herein, the liquification zone 40 may optionally contain equipment for removing halogens from the PO-enriched material. When the PO-enriched material is heated in the liquification zone 40, halogen enriched gases can evolve. By disengaging the evolved halogen-enriched gasses from the liquified PO-enriched material, the concentration of halogens in the PO-enriched material can be reduced.
In an embodiment or in combination with any embodiment mentioned herein, dehalogenation can be promoted by sparging a stripping gas (e.g., steam) into the liquified PO-enriched material either in the melt tank 310 or at another location in the circulation loop. As shown in
This two-phase medium introduced into the disengagement vessel 320 via stream 175 can then be flowed (e.g., by gravity) through the disengagement vessel 320, where a halogen-enriched gaseous phase is disengaged from a halogen-depleted liquid phase and removed from the disengagement vessel 320 via stream 162. Alternatively, a portion of the heated liquefied plastic 173 from the external heat exchanger 340 may bypass the stripper 330 and be introduced directly into the disengagement vessel 320. In an embodiment or in combination with any embodiment mentioned herein, a first portion of the halogen-depleted liquid phase discharged from an outlet of the disengagement vessel can be returned to the melt tank 310 in line 159, while a second portion of the halogen-depleted liquid phase can be discharged from the liquification zone as the dehalogenated, liquified, PO-enriched product stream 161. The disengaged halogen-enriched gaseous stream from the disengagement vessel 162 and from the melt tank 310 in line 164 can be removed from the liquification zone 40 for further processing and/or disposal.
In an embodiment or in combination with any embodiment mentioned herein, the dehalogenated liquified waste plastic stream 161 exiting the liquification zone 40 can have a halogen content of less than 500, less than 400, less than 300, less than 200, less than 100, less than 50, less than 10, less than 5, less than 2, less than 1, less than 0.5, or less than 0.1 ppmw. The halogen content of the liquified plastic stream 161 exiting the liquification zone 40 is not more than 95, not more than 90, not more than 75, not more than 50, not more than 25, not more than 10, or not more than 5 percent by weight of the halogen content of the PO-enriched stream introduced into the liquification zone.
As shown in
In an embodiment or in combination with any embodiment mentioned herein, the chemical recycling facility 10 may not include a liquification zone 40. Alternatively, the chemical recycling facility may include a liquification zone 40 but may not include any type of dehalogenation zone or equipment.
Referring again to
In an embodiment or in combination with any embodiment mentioned herein, the chemical recycling facility may also comprise a partial oxidation (POX) gasification facility. As used herein, the term “partial oxidation” to high temperature conversion of a carbon-containing feed into syngas (carbon monoxide, hydrogen, and carbon dioxide), where the conversion is carried out in the presence of a sub-stoichiometric amount of oxygen. The conversion can be of a hydrocarbon-containing feed and can be carried out with an amount of oxygen that is less than the stoichiometric amount of oxygen needed for complete oxidation of the feed—i.e., all carbon oxidized to carbon dioxide and all hydrogen oxidized to water. The reactions occurring within a partial oxidation (POX) gasifier include conversion of a carbon-containing feed into syngas, and specific examples include, but are not limited to partial oxidation, water gas shift, water gas—primary reactions, Boudouard, oxidation, methanation, hydrogen reforming, steam reforming, and carbon dioxide reforming. The feed to POX gasification can include solids, liquids, and/or gases. A “partial oxidation facility” or “POX gasification facility” is a facility that includes all equipment, lines, and controls necessary to carry out POX gasification of waste plastic and feedstocks derived therefrom.
In an embodiment or in combination with any embodiment mentioned herein, the present technology is generally directed to a method of producing synthesis gas (syngas) from a plastic material. The method generally comprises feeding the plastic material and an oxidizing agent comprising molecular oxygen (O2) into a POX gasifier, and performing a partial oxidation reaction within the gasifier by reacting at least a portion of the plastic material and at least a portion of the molecular oxygen. The plastic material feedstock may be in a solid or liquid form prior to being fed to the POX gasifier. The plastic material may be fed to the POX gasifier in a liquid stream (having solid plastics therein), a liquified plastic stream, and/or a plastic-containing slurry. As used herein, the term “plastic-containing slurry” refers to a mixture of plastic solids dispersed or suspended in a liquid medium. The plastic-containing slurry may also comprise non-plastic solids, such as coal (including coal particulates).
In the POX gasification facility, the feed stream(s) may be converted to syngas in the presence of a sub-stoichiometric amount of oxygen. In an embodiment or in combination with any embodiment mentioned herein, the feed stream(s) to the POX gasification facility may comprise one or more of a PO-enriched waste plastic, at least one solvolysis coproduct stream, a pyrolysis stream (including pyrolysis gas, pyrolysis oil, and/or pyrolysis residue), at least one stream from the cracking facility, at least one stream directly from the liquification zone, and/or at least one stream from the preprocessing facility. One or more of these streams may be introduced into the POX gasification facility continuously, or one or more of these streams may be introduced intermittently. When multiple types of feed streams are present, each may be introduced separately, or all or a portion of the streams may be combined so that the combined stream may be introduced into the POX gasification facility. The combining, when present, may take place in a continuous or batch manner. The feed stream(s) can be in the form of a gas, a liquid or liquified plastic, solids (usually comminuted), or a slurry.
In an embodiment or in combination with any embodiment mentioned herein, the gasification feedstock may comprise greater than 25, at least 26, at least 30, at least 35, at least 40, at least 45, or at least 50 weight percent and/or not more than 99.9, not more than 99, not more than 95, not more than 90, not more than 85, not more than 80, or not more than 75 weight percent plastic based on the weight of all solids present in the feedstock. The gasification feedstock may comprise from 26 to 99.9, from 30 to 99, from 40 to 90, from 45 to 80, or from 50 to 75 weight percent plastic based on the weight of all solids present in the feedstock. The plastic content may be determined, for example, by testing a sample of the gasification feedstock at least once per day over a period of 5 days to 30 days and recording the median value over the sample time.
In an embodiment or in combination with any embodiment mentioned herein, the gasification feedstock stream may also comprise at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, or at least 50 weight percent of one or more optional fossil fuels, based on the total weight of the gasification feedstock stream. Additionally, or in the alternative, the gasification feedstock stream may comprise not more than 99, not more than 90, not more than 80, not more than 70, not more than 60, not more than 50, not more than 40, not more than 30, not more than 20, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, or not more than 1 weight percent of one or more optional fossil fuels, based on the total weight of the gasification feedstock stream. Such fossil fuels may, for example, comprise solid fuels. Such fossil fuels may, for example, comprise organic materials that are short chain, such as those with a carbon number of less than 12, and are typically oxygenated. Exemplary fossil fuels include, but are not limited to, solid fuels (e.g., coal, petrocoke, etc.), liquid fuels (e.g., liquid hydrocarbons, liquefied fuels, etc.), gas fuels (e.g., natural gas, organic hydrocarbons, etc.) and/or other traditional fuel(s) having a positive heating value including products derived from a chemical synthesis process utilizing a traditional fossil fuel as a feedstock. Other possible fossil fuels may include, but are not limited to, fuel oil and liquid organic waste streams. The fossil fuels may include or contain one or more vitrification materials. As used herein, a “gasification feedstock” or “gasifier feed” refers to all components fed into the gasifier except oxygen.
In an embodiment or in combination with any embodiment mentioned herein, the plastic feed comprises a wet waste plastic. As used herein, the term “wet waste plastic” refers to a quantity of plastic waste (also defined herein) having a liquid content of at least 2 weight percent. The liquid content may be comprised of one or more liquid mediums, including but not limited to water, solvents, plasticizers, depolymerizers, and/or blending agents, such as those described herein. The liquid medium may comprise water, methanol, glycols (e.g., ethylene glycol, diethylene glycol, triethylene glycol), acetone, and/or heptane. The wet waste plastic may have a liquid content of at least 2, at least 5, or at least 10 weight percent and/or not more than 75, not more than 60, or not more than 50 weight percent. The wet waste plastic may comprise a quantity of plastic articles (i.e., D90 of greater than 2.54 cm (1 inch)), a quantity of plastic flakes (i.e., D90 of 0.32 cm (⅛ inch) to 2.54 cm (1 inch)), and/or a quantity of plastic fines (i.e., D90 of less than 0.32 cm (⅛ inch)).
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic comprises a slurry of plastic particulate solids dispersed or suspended in a liquid medium. The plastic particulate solids may have a D90 particle size of less than 0.64 cm (¼ inches), 0.32 cm (⅛ inches), less than 0.25 cm ( 1/10 inches), or less than 0.16 cm ( 1/16 inches). The liquid medium may comprise water, solvents, plasticizers, depolymerizers, and/or blending agents. The slurry may comprise a stable dispersion of plastic particulate solids in the liquid medium. As used herein, the term “stable dispersion” refers to a dispersion wherein the dispersed phase (e.g., plastic particulate solids) are resistant to aggregating or agglomerating (i.e., maintain a substantially consistent particle size) and remain in suspension for at least 1 minute (without agitation) from the point of dispersion formation (e.g., slurry formation). The stable dispersion may remain in suspension for at least for at least 1 minute, at least 2 minutes, at least 3 minutes, at least 5 minutes, at least 10 minutes, at least 15 minutes, or at least 20 minutes (without agitation) from the point of dispersion formation (e.g., slurry formation). The dispersed phase particles may be resistant to aggregating or agglomerating and remain in suspension from the point of dispersion formation until being fed into a processing zone (e.g., POX gasification zone/gasifier).
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic may be fed to the POX gasifier with a quantity of coal (or pet coke). The wet waste plastic may be mixed with a quantity of coal (or pet coke) to form a plastic and coal-containing mixture (i.e., a wet plastic-coal mixture). For example, a plastic material (dry plastic and/or wet waste plastic) may be added to a coal slurry and/or added to dry coal and formed into a coal/plastic slurry before being fed to the gasifier. As used herein, the term “dry coal” refers to a quantity of coal having a liquid content of less than 20% by weight, the liquid content including both inherent liquid (inherent moisture or equilibrium moisture) and surface liquid (surface moisture). Dry coal may comprise a greater amount of inherent liquid than surface liquid. In an embodiment or in combination with any embodiment mentioned herein, the dry coal is not in the form of a slurry. The dry coal may have a liquid content of less than 20, less than 15, less than 10, or less than 5 weight percent. The quantity of coal or coal feedstock may include peat, lignite, sub-bituminous, bituminous, anthracite, and/or petroleum coke (pet coke) coal types. In particular, the quantity of coal or coal feedstock may comprise anthracite and/or pet coke.
Alternatively, in an embodiment or in combination with any embodiment mentioned herein, the plastic feed comprising the wet waste plastic may be introduced to the gasifier without being combined with coal and/or without any coal being fed separately to the gasifier. The plastic feed comprising wet waste plastic may be the only gasifier feedstock. In such embodiments, the wet waste plastic may be liquified before being fed to the gasifier.
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic and/or the wet plastic-coal mixture may comprise at least 25, at least 30, at least 35, at least 40, at least 45, or at least 50 weight percent and/or not more than 98, not more than 95, not more than 90, not more than 85, not more than 80, or not more than 75 weight percent solids. The wet waste plastic and/or the wet plastic-coal mixture may comprise from 25 to 98, from 40 to 90, or from 50 to 75 weight percent solids. The solids content may include plastic materials and/or coal (or pet coke), as well as other solids such as vitrification materials. The wet waste plastic and/or the wet plastic-coal mixture may comprise at least 2, at least 5, at least 10, at least 15, at least 20, or at least 25 weight percent and/or not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, or not more than 50 weight percent of a liquid medium. The wet waste plastic and/or the wet plastic-coal mixture may comprise from 2 to 75, from 10 to 60, or from 25 to 50 weight percent of a liquid medium. The liquid medium may comprise water. In particular embodiments, the wet waste plastic and/or the wet plastic-coal mixture may comprise at least 40, at least 45, or at least 50 weight percent and/or not more than 85, not more than 80, or not more than 75 weight percent solids, and/or at least 15, at least 20, or at least 25 weight percent and/or not more than 60, not more than 55, or not more than 50 weight percent water. Alternatively, the liquid medium may comprise an organic solvent. In particular embodiments, the wet waste plastic and/or the wet plastic-coal mixture may comprise not more than 85, not more than 80, or not more than 75 weight percent solids, and/or at least 15, at least 20, or at least 25 weight percent weight percent solvent.
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic and/or the wet plastic-coal mixture may comprise at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent and/or not more than 99.9, not more than 99, not more than 98, not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent PET on a dry basis (or dry plastic basis). The wet waste plastic and/or the wet plastic-coal mixture may comprise from 1 to 99.9, from 5 to 80, or from 10 to 50, weight percent PET on a dry basis (or dry plastic basis).
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic and/or the wet plastic-coal mixture may comprise at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent and/or not more than 99.9, not more than 99, not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent polyolefins on a dry basis (or dry plastic basis). The wet waste plastic and/or the wet plastic-coal mixture may comprise from 1 to 99.9, from 20 to 99, from 40 to 95, or from 90 to 50 weight percent polyolefins on a dry basis (or dry plastic basis).
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic and/or the wet plastic-coal mixture may comprise at least 0.1, at least 1, at least 2, at least 4, or at least 6 and/or not more than 50, not more than 40, not more than 30, not more than 20, or not more than 10 weight percent PVC on a dry basis (or dry plastic basis). The wet waste plastic and/or the wet plastic-coal mixture may comprise from 0.1 to 50, from 1 to 20, or from 2 to 10 weight percent PVC on a dry basis (or dry plastic basis).
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the wet waste plastic may comprise a plastic material from a plastic separation, solvolysis, pyrolysis, cracker, and/or liquification process, within the chemical recycling facility or from outside the chemical recycling facility. As shown in
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the wet waste plastic comprises a plastic material or plastic-containing stream from the preprocessing facility 20 described herein. At least a portion of the wet waste plastic fed to the POX gasifier 50 may comprise a plastic-containing product, coproduct, by-product, and/or waste stream from one or more size reduction, washing, and/or density separation process within the preprocessing facility 20. Additionally, or in the alternative, at least a portion of the liquid content of the wet waste plastic may comprise a liquid medium used in one or more size reduction, washing, and/or density separation process within the preprocessing facility 20. For example, as shown in
In an embodiment or in combination with any embodiment mentioned herein, one or more of the POX gasifier feed stream(s) are in the form of a liquified plastic. At least a portion of the liquified plastic feedstock may comprise one or more molten, solvated, depolymerized, plasticized, and/or blended plastic materials, which may be derived from and/or include similar compositions and/or properties as the plastic-containing streams produced from the liquification/dehalogenation processes described herein. As shown in
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the wet waste plastic may comprise one or more coproduct streams 115 from the solvolysis facility 30 described herein. The solvolysis coproduct stream(s) 115 may be dried to remove at least a portion of the liquid content, or the coproduct stream(s) 115 may be fed to the POX gasifier 50 without removing any or a portion of the liquid content from the stream(s). The wet waste plastic feed from stream 115 may comprise a solvent, such as those used in the solvolysis processes described herein, making up at least a portion of the liquid content of the wet waste plastic. The wet waste plastic fed into the POX gasifier can comprise at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent of one or more solvolysis coproduct streams, based on the total weight of the plastic feed stream(s) introduced into the gasification zone 50. Additionally, or in the alternative, the plastic feed stream can comprise not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent of one or more solvolysis coproduct streams, based on the total weight of the plastic feed stream(s) introduced into the gasification zone 50. One or more coproduct and/or waste streams from the solvolysis facility 30 may be routed to the preprocessing facility 20 (stream 111) or other separation process, the liquification/dehalogenation zone (stream 113), and/or another process zone within or outside of the chemical recycling facility before being fed to the POX gasification facility 50. Exemplary solvolysis waste streams include mung, reactor purge, glycol bottoms, and/or DMT bottoms.
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the wet waste plastic feed may comprise a pyrolysis gas, pyrolysis oil, and/or pyrolysis residue stream, as described herein. The liquid component(s) of the pyrolysis gas, pyrolysis oil, and/or pyrolysis residue stream may comprise at least a portion of the liquid content of the wet waste plastic. The pyrolysis gas, pyrolysis oil, and/or pyrolysis residue wet waste plastic stream(s) may be fed directly into the POX gasifier 60, as stream 124. However, additionally or in the alternative, the pyrolysis gas, pyrolysis oil, and/or pyrolysis residue may be routed to the preprocessing facility 20 (stream 145) or other separation process, the liquification/dehalogenation zone (stream 143), and/or another process zone within or outside of the chemical recycling facility before being fed to the POX gasification facility 50. Wet waste plastic stream(s) comprising the pyrolysis gas, pyrolysis oil, and/or pyrolysis residue may be fed to the POX gasifier 50 without removing any or all of the liquid content from the stream(s).
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic fed into the gasifier may comprise a liquid plastic stream, a liquified plastic stream, a plastic slurry, a coal slurry, and/or a slurry comprising coal and plastic.
As shown in
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the size-reduced wet waste plastic (stream 816a) may be fed to a liquification zone 40 and liquified to form a liquified plastic stream 161. Additionally, or in the alternative, at least a portion of the size-reduced wet waste plastic (stream 817a) may be combined with a quantity of coal (or petcoke) to form a wet plastic-coal mixture 835a. The size-reduced wet waste plastic 817a and coal 832a may be combined, for example, in a coal size reduction process (e.g., pulverizer, rod mill, etc.) and/or coal feeder 830a and fed to the POX gasifier 50. The wet plastic-coal mixture 835a may comprise a plastic-containing slurry comprising plastic and coal particles dispersed or suspended in a liquid medium. The quantity of plastic and coal particles may have a D90 of less than 0.32 cm (⅛ inches), less than 0.25 cm ( 1/10 inches), or less than 0.16 cm ( 1/16 inches). The liquid content of the reduced-sized wet waste plastic 817a may comprise sufficient liquid such that no additional liquid medium is required to be added to produce the plastic-containing slurry. Alternatively, a liquid medium 834a (e.g., water) may be added to the wet plastic-coal mixture 835a. At least a portion of the liquified plastic 161 and/or wet plastic-coal mixture 835a described above can then be fed to the POX gasifier 50.
As shown in
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic can be fed to the POX gasifier in the form of a plastic-containing slurry. As shown in
Additionally, or in the alternative, a size reduced plastic waste feedstock or slurry 842c may be added to a quantity of coal (or petcoke) 832c before or during a coal size reducing process 830c. The size reduced plastic feedstock 842c may have a liquid content less than 20, less than 15, less than 10, or less than 5 weight percent. The size reduced plastic feedstock 842c may be added to a quantity of dry coal 832c, for example on a coal conveyor that is fed to the coal size reduction system 830c. Additionally, or in the alternative, the size reduced plastic feedstock 842c may be mixed with a quantity of coal (or petcoke) 832c within the coal size reduction system 830c, which may also include the addition of a liquid medium 834c. The coal size reduction system 830c may generally produce a coal-containing slurry 833c, which may or may not also comprise plastic.
Additionally, or in the alternative, the plastic-containing slurry 817c can be combined with the coal-containing slurry 833c (as shown) and/or with dry coal 832 to form a wet plastic-coal mixture 835c, which may be in the form of a plastic and coal slurry. The wet plastic-coal mixture 835c (or plastic and coal slurry) may then be fed into the POX gasifier 50.
In an embodiment or in combination with any embodiment mentioned herein, the wet waste plastic may comprise a plastic-containing slurry comprising plastic and coal (or petcoke) particles dispersed or suspended in a liquid medium (i.e., a plastic and coal slurry). As shown in
In an embodiment or in combination with any embodiment mentioned herein, the plastic-containing liquid, liquified, and/or slurry feed can have a viscosity of less than 3,000, less than 2,500, less than 2,000, less than 1,500, less than 1,000, less than 800, less than 750, less than 700, less than 650, less than 600, less than 550, less than 500, less than 450, less than 400, less than 350, less than 300, less than 250, less than 150, less than 100, less than 75, less than 50, less than 40, less than 30, less than 25, less than 20, less than 10, less than 5, less than 4, less than 3, less than 2, or less than 1 poise, measured using a Brookfield R/S rheometer with V80-40 vane spindle operating at a shear rate of 10 rad/s and a temperature of 350° C. Additionally, or in the alternative, the viscosity (measured at 350° C. and 10 rad/s and expressed in poise) of the plastic-containing liquid, liquified, and/or slurry feed may be not more than 95, not more than 90, not more than 75, not more than 50, not more than 25, not more than 10, not more than 5, or not more than 1 percent of the viscosity of the waste plastic stream introduced into the liquification system (measured at 350° C. and 10 rad/s and expressed in poise).
In an embodiment or in combination with any embodiment mentioned herein, the liquid, liquified, and/or slurry feed can have a halogen content of less than 500, less than 400, less than 300, less than 200, less than 100, less than 50, less than 10, less than 5, less than 2, less than 1, less than 0.5, or less than 0.1 ppmw. Alternatively, or in addition, the liquid, liquified, and/or slurry feed can include at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent and/or not more than 99.9, not more than 99, not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent of one or more polyolefins, based on the total weight of the stream. The liquid, liquified, and/or slurry feed can include from 1 to 99.9, from 10 to 99, from 20 to 95, from 30 to 90, from 40 to 85, or from 50 to 80 weight percent of one or more polyolefins, based on the total weight of the stream.
In an embodiment or in combination with any embodiment mentioned herein, the plastic-containing liquid, liquified, and/or slurry stream may be fed into the gasifier at a flow rate of greater than 1000, greater than 5000, greater than 10,000, greater than 20,000, greater than 40,000, greater than 80,000, or greater than 120,000 lbs/hr and/or not more than 500,000, not more than 400,000, not more than 300,000, not more than 200,000, or not more than 150,000 lbs/hr. The plastic-containing liquid, liquified, and/or slurry stream may be fed into the gasifier at a flow rate of from 1000 to 500,000, from 80,000 to 300,000, or from 120,000 to 150,000 lbs/hr. The plastic-containing liquid, liquified, and/or slurry stream may comprise at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 weight percent of the streams being fed to the POX gasifier.
The POX gasification facility includes at least one POX gasification reactor. An exemplary POX gasification reactor 52 is shown in
Additionally, or alternatively, POX gasification unit may conduct solid-fed POX gasification. As used herein, “solid-fed POX gasification” refers to a POX gasification process where the feed to the process comprises predominately (by weight) components that are solid at 25° C. and 1 atm.
Gas-fed, liquid-fed, and solid-fed POX gasification processes can be co-fed with lesser amounts of other components having a different phase at 25° C. and 1 atm. Thus, gas-fed POX gasifiers can be co-fed with liquids and/or solids, but only in amounts that are less (by weight) than the amount of gasses fed to the gas-phase POX gasifier; liquid-fed POX gasifiers can be co-fed with gasses and/or solids, but only in amounts (by weight) less than the amount of liquids fed to the liquid-fed POX gasifier; and solid-fed POX gasifiers can be co-fed with gasses and/or liquids, but only in amounts (by weight) less than the amount of solids fed to the solid-fed POX gasifier.
In an embodiment or in combination with any embodiment mentioned herein, the total feed to a gas-fed POX gasifier can comprise at least 60, at least 70, at least 80, at least 90, or at least 95 weight percent of components that are gaseous at 25° C. and 1 atm; the total feed to a liquid-fed POX gasifier can comprise at least 60, at least 70, at least 80, at least 90, or at least 95 weight percent of components that are liquid at 25° C. and 1 atm; and the total feed to a solid-fed POX gasifier can comprise at least 60, at least 70, at least 80, at least 90, or at least 95 weight percent of components that are solids at 25° C. and 1 atm.
As generally shown in
In an embodiment or in combination with any embodiment mentioned herein, the oxidizing agent in stream 180 comprises an oxidizing gas that can include air, oxygen-enriched air, or molecular oxygen (O2). The oxidizing agent can comprise at least 25, at least 35, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, at least 95, at least 97, at least 99, or at least 99.5 mole percent of molecular oxygen based on the total moles of all components in the oxidizing agent stream 180 injected into the reaction (combustion) zone of the gasification reactor 52. The particular amount of oxygen as supplied to the reaction zone can be sufficient to obtain near or maximum yields of carbon monoxide and hydrogen obtained from the gasification reaction relative to the components in the feed stream 116, considering the amount relative to the feed stream, and the amount of feed charged, the process conditions, and the reactor design.
The oxidizing agent can include other oxidizing gases or liquids, in addition to or in place of air, oxygen-enriched air, and molecular oxygen. Examples of such oxidizing liquids suitable for use as oxidizing agents include water (which can be added as a liquid or as steam) and ammonia. Examples of such oxidizing gases suitable for use as oxidizing agents include carbon monoxide, carbon dioxide, and sulfur dioxide.
In an embodiment or in combination with any embodiment mentioned herein, an atomization enhancing fluid is fed to the gasification zone along with the feedstock and oxidizing agent. As used herein, the term “atomization enhancing fluid” refers to a liquid or gas operable to reduce viscosity to decrease dispersion energy, or increase energy available to assist dispersion. The atomization enhancing fluid may be mixed with the plastic-containing feedstock before the feedstock is fed into the gasification zone or separately added to the gasification zone, for example to an injection assembly coupled with the gasification reactor. In an embodiment or in combination with any embodiment mentioned herein, the atomization enhancing fluid is water and/or steam. However, in an embodiment or in combination with any embodiment mentioned herein, steam and/or water is not supplied to the gasification zone.
In an embodiment or in combination with any embodiment mentioned herein, a gas stream enriched in carbon dioxide or nitrogen (e.g., greater than the molar quantity found in air, or at least 2, at least 5, at least 10, or at least 40 mole percent) is charged into the gasifier. These gases may serve as carrier gases to propel a feedstock to a gasification zone. Due to the pressure within the gasification zone, these carrier gases may be compressed to provide the motive force for introduction into the gasification zone. This gas stream may be compositionally the same as or different than the atomization enhancing fluid. In one or more embodiments, this gas stream also functions as the atomization enhancing fluid.
In an embodiment or in combination with any embodiment mentioned herein, a gas stream enriched in hydrogen (H2) (e.g., at least 1, at least 2, at least 5, at least 10, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, or at least 90 mole percent is charged into the gasifier. Hydrogen may be added to affect the partial oxidation reactions so as to control the resulting syngas composition.
In an embodiment or in combination with any embodiment mentioned herein, no gas stream containing more than 0.01 or more than 0.02 mole percent of carbon dioxide is charged to the gasifier or gasification zone. Alternatively, no gas stream containing more than 77, more than 70, more than 50, more than 30, more than 10, more than 5, or more than 3 mole percent nitrogen is charged to the gasifier or gasification zone. Furthermore, a gaseous hydrogen stream more than 0.1, more than 0.5, more than 1, or more than 5 mole percent hydrogen is not charged to the gasifier or to the gasification zone. Moreover, a stream of methane gas containing more than 0.1, more than 0.5, more than 1, or more than 5 mole percent methane is not charged to the gasifier or to the gasification zone. In certain embodiments, the only gaseous stream introduced to the gasification zone is the oxidizing agent.
The gasification process can be a partial oxidation (POX) gasification reaction, as described previously. Generally, to enhance the production of hydrogen and carbon monoxide, the oxidation process involves partial, rather than complete, oxidization of the gasification feedstock and, therefore, may be operated in an oxygen-lean environment, relative to the amount needed to completely oxidize 100 percent of the carbon and hydrogen bonds. In an embodiment or in combination with any embodiment mentioned herein, the total oxygen requirements for the gasifier may be at least 5, at least 10, at least 15, or at least 20 percent in excess of the amount theoretically required to convert the carbon content of the gasification feedstock to carbon monoxide. In general, satisfactory operation may be obtained with a total oxygen supply of 10 to 80 percent in excess of the theoretical requirements. For example, examples of suitable amounts of oxygen per pound of carbon may be in the range of 0.4 to 3.0, 0.6 to 2.5, 0.9 to 2.5, or 1.2 to 2.5 pounds free oxygen per pound of carbon.
Mixing of the feedstock stream and the oxidizing agent may be accomplished entirely within the reaction zone by introducing the separate streams of feedstock and oxidizing agent so that they impinge upon each other within the reaction zone. In an embodiment or in combination with any embodiment mentioned herein, the oxidizing agent stream is introduced into the reaction zone of the gasifier as high velocity to both exceed the rate of flame propagation and to improve mixing with the feedstock stream. In an embodiment or in combination with any embodiment mentioned herein, the oxidant may be injected into the gasification zone in the range of 25 to 500, 50 to 400, or 100 to 400 feet per second. These values would be the velocity of the gaseous oxidizing agent stream at the injector-gasification zone interface, or the injector tip velocity. Mixing of the feedstock stream and the oxidizing agent may also be accomplished outside of the reaction zone. For example, in an embodiment or in combination with any embodiment mentioned herein, the feedstock, oxidizing agent, and/or atomization enhancing fluid can be combined in a conduit upstream of the gasification zone or in an injection assembly coupled with the gasification reactor.
In an embodiment or in combination with any embodiment mentioned herein, the gasification feedstock stream, the oxidizing agent, and/or the atomization enhancing fluid can optionally be preheated to a temperature of at least 200° C., at least 300° C., or at least 400° C. However, the gasification process employed does not require preheating the feedstock stream to efficiently gasify the feedstock and a pre-heat treatment step may result in lowering the energy efficiency of the process.
In an embodiment or in combination with any embodiment mentioned herein, the type of gasification technology employed may be a partial oxidation entrained flow gasifier that generates syngas. This technology is distinct from fixed bed (alternatively called moving bed) gasifiers and from fluidized bed gasifiers. An exemplary gasifier that may be used in depicted in U.S. Pat. No. 3,544,291, the entire disclosure of which is incorporated herein by reference to the extent not inconsistent with the present disclosure. However, in an embodiment or in combination with any embodiment mentioned herein, other types of gasification reactors may also be used within the scope of the present technology.
In an embodiment or in combination with any embodiment mentioned herein, the gasifier/gasification reactor can be non-catalytic, meaning that the gasifier/gasification reactor does not contain a catalyst bed and the gasification process is non-catalytic, meaning that a catalyst is not introduced into the gasification zone as a discrete unbound catalyst. Furthermore, in an embodiment or in combination with any embodiment mentioned herein, the gasification process may not be a slagging gasification process; that is, operated under slagging conditions (well above the fusion temperature of ash) such that a molten slag is formed in the gasification zone and runs along and down the refractory walls.
In an embodiment or in combination with any embodiment mentioned herein, the gasification zone, and optionally all reaction zones in the gasifier/gasification reactor, may be operated at a temperature of at least 1000° C., at least 1100° C., at least 1200° C., at least 1250° C., or at least 1300° C. and/or not more than 2500° C., not more than 2000° C., not more than 1800° C., or not more than 1600° C. The reaction temperature may be autogenous. Advantageously, the gasifier operating in steady state mode may be at an autogenous temperature and does not require application of external energy sources to heat the gasification zone.
In an embodiment or in combination with any embodiment mentioned herein, the gasifier is a predominately gas fed gasifier.
In an embodiment or in combination with any embodiment mentioned herein, the gasifier is a non-slagging gasifier or operated under conditions not to form a slag.
In an embodiment or in combination with any embodiment mentioned herein, the gasifier may not be under negative pressure during operations, but rather can be under positive pressure during operation.
In an embodiment or in combination with any embodiment mentioned herein, the gasifier may be operated at a pressure within the gasification zone (or combustion chamber) of at least 200 psig (1.38 MPa), 300 psig (2.06 MPa), 350 psig (2.41 MPa), 400 psig (2.76 MPa), 420 psig (2.89 MPa), 450 psig (3.10 MPa), 475 psig (3.27 MPa), 500 psig (3.44 MPa), 550 psig (3.79 MPa), 600 psig (4.13 MPa), 650 psig (4.48 MPa), 700 psig (4.82 MPa), 750 psig (5.17 MPa), 800 psig (5.51 MPa), 900 psig (6.2 MPa), 1000 psig (6.89 MPa), 1100 psig (7.58 MPa), or 1200 psig (8.2 MPa). Additionally or alternatively, the gasifier may be operated at a pressure within the gasification zone (or combustion chamber) of not more than 1300 psig (8.96 MPa), 1250 psig (8.61 MPa), 1200 psig (8.27 MPa), 1150 psig (7.92 MPa), 1100 psig (7.58 MPa), 1050 psig (7.23 MPa), 1000 psig (6.89 MPa), 900 psig (6.2 MPa), 800 psig (5.51 MPa), or 750 psig (5.17 MPa).
Examples of suitable pressure ranges include 300 to 1000 psig (2.06 to 6.89 MPa), 300 to 750 psig (2.06 to 5.17 MPa), 350 to 1000 psig (2.41 to 6.89 MPa), 350 to 750 psig (2.06 to 5.17 MPa), 400 to 1000 psig (2.67 to 6.89 MPa), 420 to 900 psig (2.89 to 6.2 MPa), 450 to 900 psig (3.10 to 6.2 MPa), 475 to 900 psig (3.27 to 6.2 MPa), 500 to 900 psig (3.44 to 6.2 MPa), 550 to 900 psig (3.79 to 6.2 MPa), 600 to 900 psig (4.13 to 6.2 MPa), 650 to 900 psig (4.48 to 6.2 MPa), 400 to 800 psig (2.67 to 5.51 MPa), 420 to 800 psig (2.89 to 5.51 MPa), 450 to 800 psig (3.10 to 5.51 MPa), 475 to 800 psig (3.27 to 5.51 MPa), 500 to 800 psig (3.44 to 5.51 MPa), 550 to 800 psig (3.79 to 5.51 MPa), 600 to 800 psig (4.13 to 5.51 MPa), 650 to 800 psig (4.48 to 5.51 MPa), 400 to 750 psig (2.67 to 5.17 MPa), 420 to 750 psig (2.89 to 5.17 MPa), 450 to 750 psig (3.10 to 5.17 MPa), 475 to 750 psig (3.27 to 5.17 MPa), 500 to 750 psig (3.44 to 5.17 MPa), or 550 to 750 psig (3.79 to 5.17 MPa).
Generally, the average residence time of gases in the gasifier reactor can be very short to increase throughput. Since the gasifier may be operated at high temperature and pressure, substantially complete conversion of the feedstock to gases can occur in a very short time frame. In an embodiment or in combination with any embodiment mentioned herein, the average residence time of the gases in the gasifier can be not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, or not more than 7 seconds.
To avoid fouling downstream equipment from the gasifier, and the piping in-between, the resulting raw syngas stream 127 may have a low or no tar content. In an embodiment or in combination with any embodiment mentioned herein, the syngas stream discharged from the gasifier may comprise not more than 4, not more than 3, not more than 2, not more than 1, not more than 0.5, not more than 0.2, not more than 0.1, or not more than 0.01 weight percent of tar based on the weight of all condensable solids in the syngas stream. For purposes of measurement, condensable solids are those compounds and elements that condense at a temperature of 15° C. and 1 atm. Examples of tar products include naphthalenes, cresols, xylenols, anthracenes, phenanthrenes, phenols, benzene, toluene, pyridine, catechols, biphenyls, benzofurans, benzaldehydes, acenaphthylenes, fluorenes, naphthofurans, benzanthracenes, pyrenes, acephenanthrylenes, benzopyrenes, and other high molecular weight aromatic polynuclear compounds. The tar content can be determined by GC-MSD.
Generally, the raw syngas stream 127 discharged from the gasification vessel includes such gases as hydrogen, carbon monoxide, and carbon dioxide and can include other gases such as methane, hydrogen sulfide, and nitrogen depending on the fuel source and reaction conditions.
In an embodiment or in combination with any embodiment mentioned herein, the raw syngas stream 127 (the stream discharged from the gasifier and before any further treatment by way of scrubbing, shift, or acid gas removal) can have the following composition in mole percent on a dry basis and based on the moles of all gases (elements or compounds in gaseous state at 25° C. and 1 atm) in the raw syngas stream 127:
In an embodiment or in combination with any embodiment mentioned herein, the syngas comprises a molar hydrogen/carbon monoxide ratio of 0.7 to 2, 0.7 to 1.5, 0.8 to 1.2, 0.85 to 1.1, or 0.9 to 1.05.
The gas components can be determined by Flame Ionization Detector Gas Chromatography (FID-GC) and Thermal Conductivity Detector Gas Chromatography (TCD-GC) or any other method recognized for analyzing the components of a gas stream.
In an embodiment or in combination with any embodiment mentioned herein, the recycle content syngas can have a recycle content of at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent, based on the total weight of the syngas stream.
It should be understood that the following is not intended to be an exclusive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, when accompanying the use of a defined term in context.
As used herein, the terms “a,” “an,” and “the” mean one or more.
As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.
As used herein, the phrase “at least a portion” includes at least a portion and up to and including the entire amount or time period.
As used herein, the term “caustic” refers to any basic solution (e.g., strong bases, concentrated weak bases, etc.) that can be used in the technology as a cleaning agent, for killing pathogens, and/or reducing odors.
As used herein, the term “centrifugal density separation” refers to a density separation process where the separation of materials is primarily cause by centrifugal forces.
As used herein, the term “chemical recycling” refers to a waste plastic recycling process that includes a step of chemically converting waste plastic polymers into lower molecular weight polymers, oligomers, monomers, and/or non-polymeric molecules (e.g., hydrogen, carbon monoxide, methane, ethane, propane, ethylene, and propylene) that are useful by themselves and/or are useful as feedstocks to another chemical production process(es).
As used herein, the term “chemical recycling facility” refers to a facility for producing a recycle content product via chemical recycling of waste plastic. A chemical recycling facility can employ one or more of the following steps: (i) preprocessing, (ii) solvolysis, (iii) pyrolysis, (iv) cracking, and/or (v) POX gasification.
As used herein, the term “co-located” refers to the characteristic of at least two objects being situated on a common physical site, and/or within one mile of each other.
As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.
As used herein, the term “conducting” refers to the transport of a material in a batchwise and/or continuous manner.
As used herein, the term “cracking” refers to breaking down complex organic molecules into simpler molecules by the breaking of carbon-carbon bonds.
As used herein, the term “D90” refers to a specified diameter where ninety percent of a distribution of particles has a smaller diameter than the specified diameter and ten percent has a larger diameter than the specified diameter. To ensure that a representative D90 value is obtained, the sample size of the particles should be at least one pound. To determine a D90 for particles in a continuous process, testing should be performed on at least 5 samples that are taken at equal time intervals over at least 24 hours. Testing for D90 is performed using high-speed photography and computer algorithms to generate a particle size distribution. One suitable particle size analyzer for determining D90 values is the Model CPA 4-1 Computerized Particle Analyzer from W.S Tyler of Mentor, Ohio.
As used herein, the term “diameter” means the maximum chord length of a particle (i.e., its largest dimension).
As used herein, the term “density separation process” refers to a process for separating materials based, at least in part, upon the respective densities of the materials. Moreover, the terms “low-density separation stage” and “high-density separation stage” refer to relative density separation processes, wherein the low-density separation has a target separation density less than the target separation density of the high-density separation stage.
As used herein, the term “depleted” refers to having a concentration (on a dry weight basis) of a specific component that is less than the concentration of that component in a reference material or stream.
As used herein, the term “directly derived” refers to having at least one physical component originating from waste plastic.
As used herein, the term “dry coal” refers to a quantity of coal having a liquid content of less than 20% by weight, the liquid content including both inherent liquid (inherent moisture or equilibrium moisture) and surface liquid (surface moisture).
As used herein, the term “enriched” refers to having a concentration (on a dry weight basis) of a specific component that is greater than the concentration of that component in a reference material or stream.
As used herein, a “gasification feedstock” or “gasifier feed” refers to all components fed into the gasifier except oxygen.
As used herein, the term “halide” refers to a composition comprising a halogen atom bearing a negative charge (i.e., a halide ion).
As used herein, the term “halogen” or “halogens” refers to organic or inorganic compounds, ionic, or elemental species comprising at least one halogen atom.
As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.
As used herein, the term “heavy organic methanolysis coproduct” refers to a methanolysis coproduct with a boiling point greater than DMT.
As used herein, the term “heavy organic solvolysis coproduct” refers to a solvolysis coproduct with a boiling point greater than the principal terephthalyl product of the solvolysis facility.
As used herein, the terms “including,” “include,” and “included” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.
As used herein, the term “indirectly derived” refers to having an assigned recycle content i) that is attributable to waste plastic, but ii) that is not based on having a physical component originating from waste plastic.
As used herein, the term “isolated” refers to the characteristic of an object or objects being by itself or themselves and separate from other materials, in motion or static.
As used herein, the term “light organic methanolysis coproduct” refers to a methanolysis coproduct with a boiling point less than DMT.
As used herein, the term “light organics solvolysis coproduct” refers to a solvolysis coproduct with a boiling point less than the principal terephthalyl product of the solvolysis facility.
As used herein, the term “methanolysis coproduct” refers to any compound withdrawn from a methanolysis facility that is not dimethyl terephthalate (DMT), ethylene glycol (EG), or methanol.
As used herein, the terms “mixed plastic waste” and “MPW” refer to a mixture of at least two types of waste plastics including, but not limited to the following plastic types: polyethylene terephthalate (PET), one or more polyolefins (PO), and polyvinylchloride (PVC).
As used herein, the term “partial oxidation (POX)” or “POX” refers to high temperature conversion of a carbon-containing feed into syngas, (carbon monoxide, hydrogen, and carbon dioxide), where the conversion is carried out in the presence of a less than stoichiometric amount of oxygen. The feed to POX gasification can include solids, liquids, and/or gases.
As used herein, the term “partial oxidation (POX) reaction” refers to all reactions occurring within a partial oxidation (POX) gasifier in the conversion of a carbon-containing feed into syngas, including but not limited to partial oxidation, water gas shift, water gas—primary reactions, Boudouard, oxidation, methanation, hydrogen reforming, steam reforming, and carbon dioxide reforming.
As used herein, “PET” means a homopolymer of polyethylene terephthalate, or polyethylene terephthalate modified with modifiers or containing residues or moieties of other than ethylene glycol and terephthalic acid, such as isophthalic acid, 1,4-cyclohexanedicarboxylic acid, diethylene glycol, TMCD (2,2,4,4-tetramethyl-1,3-cyclobutanediol), CHDM (cyclohexanedimethanol), propylene glycol, isosorbide, 1,4-butanediol, 1,3-propane diol, and/or NPG (neopentyl glycol), or polyesters having repeating terephthalate units (and whether or not they contain repeating ethylene glycol based units) and one or more residues or moieties of TMCD (2,2,4,4-tetramethyl-1,3-cyclobutanediol), CHDM (cyclohexanedimethanol), propylene glycol, or NPG (neopentyl glycol), isosorbide, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, 1,4-butanediol, 1,3-propane diol, and/or diethylene glycol, or combinations thereof.
As used herein, the term “overhead” refers to the physical location of a structure that is above a maximum elevation of quantity of particulate plastic solids within an enclosed structure.
As used herein, the term “partial oxidation (POX) gasification facility” or “POX Facility” refers to a facility that includes all equipment, lines, and controls necessary to carry out POX gasification of waste plastic and feedstocks derived therefrom.
As used herein, the term “partially processed waste plastic” means waste plastic that has been subjected to at least on automated or mechanized sorting, washing, or comminuted step or process. Partially processed waste plastics may originate from, for example, municipal recycling facilities (MRFs) or reclaimers. When partially processed waste plastic is provided to the chemical recycling facility, one or more preprocessing steps may me skipped.
As used herein, the term “PET solvolysis” refers to a reaction by which a polyester terephthalate-containing plastic feed is chemically decomposed in the presence of a solvent to form a principal terephthalyl product and/or a principal glycol product.
As used herein, the term “physical recycling” (also known as “mechanical recycling”) refers to a waste plastic recycling process that includes a step of melting waste plastic and forming the molten plastic into a new intermediate product (e.g., pellets or sheets) and/or a new end product (e.g., bottles). Generally, physical recycling does not substantially change the chemical structure of the plastic, although some degradation is possible.
As used herein, the term “predominantly” means more than 50 percent by weight. For example, a predominantly propane stream, composition, feedstock, or product is a stream, composition, feedstock, or product that contains more than 50 weight percent propane.
As used herein, the term “preprocessing” refers to preparing waste plastic for chemical recycling using one or more of the following steps: (i) comminuting, (ii) particulating, (iii) washing, (iv) drying, and/or (v) separating.
As used herein, the term “pyrolysis” refers to thermal decomposition of one or more organic materials at elevated temperatures in an inert (i.e., substantially oxygen free) atmosphere.
As used herein, the term “pyrolysis char” refers to a carbon-containing composition obtained from pyrolysis that is solid at 200° C. and 1 atm.
As used herein, the term “pyrolysis gas” refers to a composition obtained from pyrolysis that is gaseous at 25° C.
As used herein, the term “pyrolysis heavy waxes” refers to C20+ hydrocarbons obtained from pyrolysis that are not pyrolysis char, pyrolysis gas, or pyrolysis oil.
As used herein, the terms “pyrolysis oil” or “pyoil” refers to a composition obtained from pyrolysis that is liquid at 25° C. and 1 atm.
As used herein, the term “pyrolysis residue” refers to a composition obtained from pyrolysis that is not pyrolysis gas or pyrolysis oil and that comprises predominantly pyrolysis char and pyrolysis heavy waxes.
As used herein, the term “recycle content” and “r-content” refer to being or comprising a composition that is directly and/or indirectly derived from waste plastic.
As used herein, the term “resin ID code” refers to the set of symbols and associated number (1 through 7) appearing on plastic products that identify the plastic resin out of which the product is made, developed originally in 1988 in the United States but since 2008 has been administered by ASTM International.
As used herein, the term “resin ID code 1” refers to plastic products made from polyethylene terephthalate (PET). Such plastic products may include soft drink bottles, mineral water bottles, juice containers, and cooking oil containers.
As used herein, the term “resin ID code 2” refers to plastic products made from high-density polyethylene (HDPE). Such plastic products may include milk jugs, cleaning agent and laundry detergent containers, shampoo bottles, and soap containers.
As used herein, the term “resin ID code 3” refers to plastic products made from polyvinyl chloride (PVC). Such plastic products may include fruit and sweets trays, plastic packing (bubble foil), and food wrap.
As used herein, the term “resin ID code 4” refers to plastic products made from low-density polyethylene (LDPE). Such plastic products may include shopping bags, light weight bottles, and sacks.
As used herein, the term “resin ID code 5” refers to plastic products made from polypropylene (PP). Such plastic products may include furniture, auto parts, industrial fibers, luggage, and toys.
As used herein, the term “resin ID code 6” refers to plastic products made from polystyrene (PS). Such plastic products may include toys, hard packing, refrigerator trays, cosmetic bags, costume jewelry, CD cases, vending cups, and clamshell containers.
As used herein, the term “resin ID code 7” refers to plastic products made from plastics other than those defined as resin ID codes 1-6, including but not limited to, acrylic, polycarbonate, polyactic fibers, nylon, and fiberglass. Such plastic products may include bottles, headlight lenses, and safety glasses.
As used herein, the term “separation efficiency” refers to the degree of separation between at two or more phases or components as defined in
As used herein, the term “sink-float density separation” refers to a density separation process where the separation of materials is primarily caused by floating or sinking in a selected liquid medium.
As used herein, the term “size-reduced” refers to a quantity of plastic particles from a process having a D90 less than the D90 of the quantity of plastic material fed into the process.
As used herein, the term “solvolysis” or “ester solvolysis” refers to a reaction by which an ester-containing feed is chemically decomposed in the presence of a solvent to form a principal carboxyl product and/or a principal glycol product. Examples of solvolysis include, hydrolysis, alcoholysis, and ammonolysis.
As used herein, the term “solvolysis coproduct” refers to any compound withdrawn from a solvolysis facility that is not the principal carboxyl (terephthalyl) product of the solvolysis facility, the principal glycol product of the solvolysis facility, or the principal solvent fed to the solvolysis facility.
As used herein, the term “terephthalyl” refers to a molecule including the following group:
As used herein, the term “principal terephthalyl” refers to the main or key terephthalyl product being recovered from the solvolysis facility.
As used herein, the term “glycol” refers to a component comprising two or more —OH functional groups per molecule.
As used herein, the term “principal glycol” refers to the main glycol product being recovered from the solvolysis facility.
As used herein, the term “stable dispersion” refers to a dispersion wherein the dispersed phase (e.g., plastic particulate solids) are resistant to aggregating or agglomerating (i.e., maintain a substantially consistent particle size) and remain in suspension for at least 1 minute (without agitation) from the point of dispersion formation (e.g., slurry formation).
As used herein, the term “target separation density” refers to a density above which materials subjected to a density separation process are preferentially separated into the higher-density output and below which materials are separated in the lower-density output.
As used herein, the terms “waste plastic” and “plastic waste” refer to used, scrap, and/or discarded plastic materials. The waste plastic fed to the chemical recycling facility may be unprocessed or partially processed.
As used herein, the term “unprocessed waste plastic” means waste plastic that has not be subjected to any automated or mechanized sorting, washing, or comminuting. Examples of unprocessed waste plastic include waste plastic collected from household curbside plastic recycling bins or shared community plastic recycling containers.
As used herein, the phrase “at least a portion” includes at least a portion and up to and including the entire amount or time period.
As used herein, the term “waste plastic particulates” refers to waste plastic having a D90 of less than 1 inch.
As used herein, the term “wet waste plastic” refers to a quantity of plastic waste (also defined herein) having a liquid content of at least 2 weight percent.
As used herein, the term “predominantly” means at least 50 weight percent of something, based on its total weight. For example, a composition comprising “predominantly” component A includes at least 50 weight percent of component A, based on the total weight of the composition.
As used herein, “downstream” means a target unit operation, vessel, or equipment that:
The preferred forms of the invention described above are to be used as illustration only and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention.
The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2021/026994 | 4/13/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63008923 | Apr 2020 | US |
