Patent Application
20250188364
Waste plastic pyrolysis plays a part in a variety of chemical recycling technologies. The pyrolysis of waste plastic produces heavy components (e.g., waxes, tar, and char), as well as recycle content pyrolysis oil (r-pyoil) and recycle content pyrolysis gas (r-pygas). When the pyrolysis facility is located near another processing facility, such as a cracker facility, it is desirable to send as much of the r-pyoil and r-pygas as possible to the downstream processing facility to be used as a feedstock in forming other recycle content products (e.g., olefins, paraffins, etc.).
However, when pyrolysis facilities are added to existing downstream facilities, such as a cracking facility, the direct recovery of desirable recycle products from the pyrolysis effluent may not be considered. Consequently, even though recycle content products are being produced by the pyrolysis facilities, these recycle content products are typically broken down in downstream processes and not sufficiently recovered. Therefore, such combined facilities may exhibit one or more process deficiencies that negatively impact the ability to directly recover valuable recycle content products from the pyrolysis effluent. Thus, a processing scheme for waste plastic pyrolysis that provides superior recycle content product recovery is needed.
In one aspect, the present technology concerns a chemical recycling process. Generally, the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis oil stream; (b) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; and (c) introducing at least a portion of the raffinate stream into a cracker furnace.
In one aspect, the present technology concerns a chemical recycling process. Generally, the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent; (b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream; (c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; (d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed; (e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; (f) compressing at least a portion of the cracked product in at least one compressor to form a compressed product; and (g) separating at least one hydrocarbon from the compressed product to thereby form a recycle content hydrocarbon stream.
In one aspect, the present technology concerns a chemical recycling process. Generally, the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent; (b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream; (c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; (d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed; (e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; and (f) subjecting at least a portion of the extract stream to a chemical process so as to synthesize a chemical derivative and/or a polymer therefrom.
We have discovered that high volumes of valuable recycle content products may be directly derived from waste plastic pyrolysis effluent. More particularly, we have discovered that one or more valuable recycle content hydrocarbons can be separated from recycle content pyrolysis oil prior to further treatment in a downstream cracker facility. Consequently, by recovering these valuable recycle content products upstream of the cracking facility, we can optimize recovery and utilization of recycle content products from waste plastics.
As shown in
Turning now to
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.
In an embodiment or in combination with any embodiment mentioned herein, 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.
Turning again to
In an embodiment or in combination with any embodiment mentioned herein, the mixed waste plastic (MPW) includes at least two distinct types of plastic.
In an embodiment or in combination with any embodiment mentioned herein, all or a portion of the MPW in the waste plastic stream 32 can originate from a municipal recycling facility (MRF).
In an embodiment or in combination with any embodiment mentioned herein, all or a portion of the MPW in the waste plastic stream 32 can originate from a reclaimer facility.
Examples of suitable waste plastics can include, but are not limited to, polyolefins (PO), aromatic and aliphatic polyesters, polyvinyl chloride (PVC), polystyrene, cellulose esters, 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, and urea-containing polymers and melamines.
Examples of specific polyolefins may include linear low-density polyethylene (LLDPE), low density polyethylene (LDPE), polymethylpentene, polybutene-1, high density polyethylene (HDPE), atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, crosslinked polyethylene, amorphous polyolefins, and the copolymers of any one of the aforementioned polyolefins.
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. 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).
In an embodiment or in combination with any embodiment mentioned herein, the waste plastic stream 32 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, at least 95, or at least 99 weight percent of one or more polyolefins, based on the total weight of the stream. Alternatively, or in addition, the waste plastic stream 32 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 of one or more polyolefins, based on the total weight of the stream.
In one embodiment or in combination with any of the mentioned embodiments, the waste plastic stream 32 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 polyesters, based on the total weight of the stream.
In one embodiment or in combination with any of the mentioned embodiments, the waste plastic stream 32 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, based on the total weight of the stream. 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 an embodiment or in combination with any embodiment mentioned herein, the waste plastic stream 32 can include 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 the stream.
The general configuration and operation of each of the facilities that may be present in the chemical recycling facility 10 shown in
As shown in
In an embodiment or in combination with any embodiment mentioned herein, the preprocessing facility of the waste plastic source 22 may include at least one separation step or zone. The separation step or zone may be configured to separate the waste plastic stream 32 into two or more streams enriched in certain types of plastics. Such separation is particularly advantageous when the waste plastic fed to the chemical recycling facility 10 is MWP.
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, a PET-enriched stream and a PO-enriched stream. 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.
Referring again to
The waste plastic stream 32 may be introduced into a plastic liquification zone prior to being introduced into the pyrolysis reactor 12. The plastic liquification zone may be present in the waste plastic source 22 or it may be positioned separately and independently. As used herein, the term “liquification” zone refers to a chemical processing zone or step in which at least a portion of the incoming plastic is liquefied. The step of liquefying plastic can include chemical liquification, physical liquification, or combinations thereof. Exemplary methods of liquefying the plastic introduced in the liquification zone can include: (i) heating/melting; (ii) dissolving in a solvent; (iii) depolymerizing; (iv) plasticizing; and combinations thereof. Additionally, one or more of options (i) through (iv) may also be accompanied by the addition of a blending or liquification agent to help facilitate the liquification (reduction of viscosity) of the polymer material. As such, a variety of rheology modification agents (e.g., solvents, depolymerization agents, plasticizers, and blending agents) can be used the enhance the flow and/or dispersibility of the liquified waste plastic.
When added to the liquification zone, 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) originally present in the waste plastic stream 32 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. This dissolution solvent can be added directly to the liquification vessel in the liquification zone, or it can be previously combined with one or more streams fed to the liquification zone, including the waste plastic stream 32.
In an embodiment or in combination with any embodiment mentioned herein, the dissolution solvent can comprise a stream withdrawn from one or more other facilities within the chemical recycling facility 10. For example, the solvent can comprise a stream withdrawn from the pyrolysis reactor 12 and/or the separation zone. In certain embodiments, the dissolution solvent can be or comprise pyrolysis oil.
In some cases, the waste 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 polyolefins). 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 waste plastic stream 32, 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 waste plastic stream 32.
Further, one or more of the methods of liquefying the waste plastic stream 32 can also include adding at least one blending agent to the plastic stream before, during, or after the liquification process in the liquification zone. 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 waste plastic stream 32, 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 waste plastic stream 32.
In an embodiment or in combination with any embodiment mentioned herein, a portion of the pyrolysis oil stream withdrawn from the condenser 24 can be combined with the waste plastic stream 32 to form a liquified plastic. Generally, in such embodiments, all or a portion of the pyrolysis oil stream may be combined with the waste plastic stream 32 prior to introduction into the liquification zone, or after the waste plastic stream 32 enters the liquification vessel within the liquification zone.
In an embodiment or in combination with any embodiment mentioned herein, the liquified (or reduced viscosity) plastic stream withdrawn from the liquification zone 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, at least 95, or at least 99 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 one or more polyolefins, based on the total weight of the stream, or the amount of polyolefins can be in the range of from 1 to 99 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 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, as measured using a Brookfield R/S rheometer with a 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 liquification zone may comprise at least one melt tank and/or at least one extruder to facilitate the plastic liquification. Additionally, in certain embodiments, the liquification zone may also contain at least one stripping column and at least one disengagement vessel to facilitate the removal of halogenated compounds that may be formed in the melt tank and/or the extruder.
In an embodiment or in combination with any embodiment mentioned herein, the melt tank and/or the extruder may receive the waste plastic feed stream and heat the waste plastic via heating mechanisms in the melt tank and/or via the extrusion process in the extruder.
In an embodiment or in combination with any embodiment mentioned herein, the melt tank can include one or more continuously stirred tanks. When one or more rheology modification agents (e.g., solvents, depolymerization agents, plasticizers, and blending agents) are used in the liquification zone, such rheology modification agents can be added to and/or mixed with the waste plastic stream 32 in or prior to introduction into the melt tank.
In an embodiment or in combination with any embodiment mentioned herein, the interior space of the liquification vessel, where the plastic is heated, is maintained at a temperature of at least 200, at least 210, at least 220, at least 230, at least 240, at least 250, at least 260, at least 270, at least 280, at least 290, at least 300, at least 310, at least 320, at least 330, at least 340, at least 350, at least 360, at least 370, at least 380, at least 390, or at least 400° C. Additionally, or in the alternative, the interior space of the liquification vessel may be maintained at a temperature of not more than 500, not more than 475, not more than 450, not more than 425, not more than 400, not more than 390, not more than 380, not more than 370, not more than 365, not more than 360, not more than 355, not more than 350, or not more than 345° C. Generally, in one or more embodiments, the interior space of the liquification vessel may be maintained at a temperature ranging from 200 to 500° C., 240 to 425° C., 280 to 380° C., or 320 to 350° C.
In an embodiment or in combination with any embodiment mentioned herein, the liquification zone may optionally contain equipment for removing halogens from the waste plastic stream 32. When the waste plastic is heated in the liquification zone, halogen enriched gases can evolve. By disengaging the evolved halogen-enriched gasses from the liquified plastics, the concentration of halogens in the liquified plastic stream 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 plastics in the melt tank.
In an embodiment or in combination with any embodiment mentioned herein, the liquified plastic stream exiting the liquification zone 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.
In an embodiment or in combination with any embodiment mentioned herein, the halogen content of the liquified plastic stream exiting the liquification zone can 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, or not more than 5 percent by weight of the halogen content of the waste plastic stream 32 introduced into the liquification zone.
In an embodiment or in combination with any embodiment mentioned herein, the liquefied waste plastic stream 32 exiting the plastic liquification system may have a temperature of at least 200, at least 225, at least 250, at least 275, at least 300, at least 310, at least 320, at least 330, or at least 340° C. and/or less than 450, less than 425, less than 400, less than 375, or less than 350° C.
As shown in
As shown in
As depicted in
In an embodiment or in combination with any embodiment mentioned herein the liquified plastic stream to the pyrolysis facility may be a PO-enriched stream of waste plastic. The liquified plastic stream introduced into the pyrolysis reactor 12 can be in the form of liquified plastic (e.g., liquified, melted, plasticized, depolymerized, or combinations thereof), plastic pellets or particulates, or a slurry thereof.
In general, the pyrolysis facility may include the plastic liquification zone, the pyrolysis reactor 12, the condenser 24 for separating the pyrolysis effluent stream 34 from the reactor, and the separator 26 for the pyrolysis oil stream (discussed below).
While in the pyrolysis reactor 12, at least a portion of the feed may be subjected to a pyrolysis reaction that produces a pyrolysis effluent comprising a pyrolysis oil, a pyrolysis gas, and a pyrolysis residue. Generally, the pyrolysis effluent stream 34 exiting the pyrolysis reactor 12 can be in the form of pyrolysis vapors that comprise the pyrolysis gas and uncondensed pyrolysis oil. As used herein, “pyrolysis vapor” refers to the uncondensed pyrolysis effluent that comprises the majority of the pyrolysis oil and the pyrolysis gas present in the pyrolysis effluent.
Pyrolysis is a process that involves the chemical and thermal decomposition of the introduced feed. Although all pyrolysis processes may be generally characterized by a reaction environment that is substantially free of oxygen, pyrolysis processes may be further defined, for example, by the pyrolysis reaction temperature within the reactor, the residence time in the pyrolysis reactor 12, the reactor type, the pressure within the pyrolysis reactor 12, and the presence or absence of pyrolysis catalysts.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis reactor 12 can be, for example, a film reactor, a screw extruder, a tubular reactor, a tank, a stirred tank reactor, a riser reactor, a fixed bed reactor, a fluidized bed reactor, a rotary kiln, a vacuum reactor, a microwave reactor, or an autoclave. In various embodiments, the pyrolysis reactor 12 may comprise a film reactor, such as a falling film reactor or an up-flow film reactor.
In an embodiment or in combination with any embodiment mentioned herein, a lift gas and/or a feed gas may be used to introduce the feedstock into the pyrolysis reactor 12 and/or facilitate various reactions within the pyrolysis reactor 12. For instance, the lift gas and/or the feed gas may comprise, consist essentially of, or consist of nitrogen, carbon dioxide, and/or steam. The lift gas and/or feed gas may be added with the waste plastic stream 32 prior to introduction into the pyrolysis reactor 12 and/or may be added directly to the pyrolysis reactor 12. The lift gas and/or feed gas can include steam and/or a reducing gas such as hydrogen, carbon monoxide, and combinations thereof.
Furthermore, the temperature in the pyrolysis reactor 12 can be adjusted so as to facilitate the production of certain end products. In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis temperature in the pyrolysis reactor 12 can range from 325 to 1,100° C., 350 to 900° C., 350 to 700° C., 350 to 550° C., 350 to 475° C., 425 to 1,100° C., 425 to 800° C., 500 to 1,100° C., 500 to 800° C., 600 to 1,100° C., 600 to 800° C., 625 to 1,000° C., 700 to 1,000° C., or 625 to 800° C. Generally, in certain embodiments, the pyrolysis temperature in the pyrolysis reactor 12 can be greater than 625° C. Alternatively, in certain embodiments, the pyrolysis temperature in the pyrolysis reactor 12 can be less than 625° C.
In an embodiment or in combination with any embodiment mentioned herein, the residence times of the feedstocks within the pyrolysis reactor 12 can be at least 0.1, at least 0.2, at least 0.3, at least 0.5, at least 1, at least 1.2, at least 1.3, at least 2, at least 3, or at least 4 seconds. Alternatively, the residence times of the feedstocks within the pyrolysis reactor 12 can be at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 20, at least 30, at least 45, at least 60, at least 75, or at least 90 minutes. Additionally, or alternatively, the residence times of the feedstocks within the pyrolysis reactor 12 can be less than 6, less than 5, less than 4, less than 3, less than 2, less than 1, or less than 0.5 hours. Furthermore, the residence times of the feedstocks within the pyrolysis reactor 12 can be less than 100, less than 90, less than 80, less than 70, less than 60, less than 50, less than 40, less than 30, less than 20, less than 10, less than 9, less than 8, less than 7, less than 6, less than 5, less than 4, less than 3, less than 2, or less than 1 seconds. More particularly, the residence times of the feedstocks within the pyrolysis reactor 12 can range from 0.1 to 10 seconds, 0.5 to 10 seconds, 30 minutes to 4 hours, or 30 minutes to 3 hours, or 1 hour to 3 hours, or 1 hour to 2 hours.
In an embodiment or in combination with any embodiment mentioned herein, the pressure within the pyrolysis reactor 12 can be maintained at atmospheric pressure or within the range of 0.1 to 100 bar, or 0.1 to 60 bar, or 0.1 to 30 bar, or 0.1 to 10 bar, 0.2 to 1.5 bar, or 0.3 to 1.1 bar. As used herein, the term “bar” refers to gauge pressure, unless otherwise noted.
In an embodiment or in combination with any embodiment mentioned herein, a pyrolysis catalyst may be introduced into the liquified plastic stream prior to introduction into the pyrolysis reactor 12 and/or introduced directly into the pyrolysis reactor 12. The catalyst can be homogenous or heterogeneous and may include, for example, certain types of zeolites and other mesostructured catalysts. In some embodiments, the pyrolysis reaction may not be catalyzed (e.g., carried out in the absence of a pyrolysis catalyst), but may include a non-catalytic, heat-retaining inert additive, such as sand, in the reactor in order to facilitate the heat transfer. Such catalyst-free pyrolysis processes may be referred to as “thermal pyrolysis.”
After exiting the pyrolysis reactor 12, the pyrolysis effluent may be separated into the pyrolysis oil stream and the pyrolysis gas stream in a separation system, such as the condenser 24 depicted in
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 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, or at least 75 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors. Additionally, or alternatively, the pyrolysis effluent or pyrolysis vapors may comprise 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, or not more than 25 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors. As discussed above, the pyrolysis oil may be in the form of uncondensed vapors in the pyrolysis effluent upon exiting the heated reactor; however, these vapors may be subsequently condensed into the resulting pyrolysis oil. The pyrolysis effluent or pyrolysis vapors may comprise in the range of 20 to 99 weight percent, 25 to 80 weight percent, 30 to 85 weight percent, 30 to 80 weight percent, 30 to 75 weight percent, 30 to 70 weight percent, or 30 to 65 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 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, or at least 80 weight percent of the pyrolysis gas, based on the total weight of the pyrolysis effluent or pyrolysis vapors. Additionally, or alternatively, the pyrolysis effluent or pyrolysis vapors may comprise 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, or not more than 45 weight percent of the pyrolysis gas, based on the total weight of the pyrolysis effluent or pyrolysis vapors. The pyrolysis effluent may comprise 1 to 90 weight percent, 10 to 85 weight percent, 15 to 85 weight percent, 20 to 80 weight percent, 25 to 80 weight percent, 30 to 75 weight percent, or 35 to 75 weight percent of the pyrolysis gas, based on the total weight of the stream.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 may comprise at least 0.5, at least 1, at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors. Additionally, or alternatively, the pyrolysis effluent may comprise not more than 60, not more than 50, 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 9, not more than 8, not more than 7, not more than 6, or not more than 5 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors. The pyrolysis effluent may comprise in the range of 0.1 to 25 weight percent, 1 to 15 weight percent, 1 to 8 weight percent, or 1 to 5 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors. This pyrolysis residue may be removed from the pyrolysis reactor 12 (where it may form) and/or separated from the pyrolysis effluent in a downstream separator, such as the condenser 24.
The resulting pyrolysis oil stream and pyrolysis gas stream may be directly used in various downstream applications based on their formulations. The various characteristics and properties of the pyrolysis oil, pyrolysis gas, and pyrolysis residue are described below. It should be noted that, while all of the following characteristics and properties may be listed separately, it is envisioned that each of the following characteristics and/or properties of the pyrolysis gas, pyrolysis oil, and/or pyrolysis residue are not mutually exclusive and may be combined and present in any combination.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil may predominantly comprise hydrocarbons having from 4 to 30 carbon atoms per molecule (e.g., C4 to C30 hydrocarbons). As used herein, the term “Cx” or “Cx hydrocarbon,” refers to a hydrocarbon compound including “x” total carbons per molecule, and encompasses all olefins, paraffins, aromatics, heterocyclic, and isomers having that number of carbon atoms. For example, each of normal, iso, and tert-butane and butene and butadiene molecules would fall under the general description “C4.” The pyrolysis oil may have a C4-C30 hydrocarbon content of 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 based on the total weight of the pyrolysis oil stream.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil can predominantly comprise C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons. For example, the pyrolysis oil may comprise 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 C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons, based on the total weight of the pyrolysis oil stream.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil may also include various amounts of diolefins and aromatics, depending on the pyrolysis reactor 12 conditions and whether a pyrolysis catalyst is employed. For example, the pyrolysis oil 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, or at least 40 weight percent of diolefins and/or aromatics, based on the total weight of the pyrolysis oil stream. Additionally, or alternatively, the pyrolysis oil may include not more than 90, not more than 80, not more than 70, not more than 60, 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, or not more than 1 weight percent of diolefins and/or aromatics, based on the total weight of the pyrolysis oil stream. As used herein, the term “aromatics” refers to the total amount (in weight) of any compounds containing an aromatic moiety, such as benzene, toluene, xylene, and styrene.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil may have a mid-boiling point in the range of 75 to 250° C., 90 to 225° C., or 115 to 190° C. as measured according to ASTM D-5399. As used herein, “mid-boiling point” refers to the median boiling point temperature of the pyrolysis oil, where 50 percent by volume of the pyrolysis oil boils above the mid-boiling point and 50 percent by volume boils below the mid-boiling point.
In an embodiment or in combination with any embodiment mentioned herein, the boiling point range of the pyrolysis oil may be such that at least 90 percent of the pyrolysis oil boils off at a temperature of 250° C., of 280° C., of 290° C., of 300° C., or of 310° C., as measured according to ASTM D-5399.
As noted above, the pyrolysis conditions, such as temperature, may be controlled so as to maximize the production of certain hydrocarbons and chemical compounds in the resulting pyrolysis gas and pyrolysis oil.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis reaction can occur at temperatures of least 625° C. In such embodiments, the pyrolysis effluent, the pyrolysis vapors, and/or the pyrolysis oil derived from such pyrolysis reactions may comprise the following compounds (all of the following weight percentages are based on the total weight of the associated stream):
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis reaction can occur at temperatures of less than 625° C. In such embodiments, the pyrolysis effluent, the pyrolysis vapors, and/or the pyrolysis oil derived from such pyrolysis reactions may comprise the following compounds (all of the following weight percentages are based on the total weight of the associated stream):
Turning to the pyrolysis gas, the pyrolysis gas can have a methane content in the range of 1 to 50 weight percent, 5 to 50 weight percent, or 15 to 45 weight percent, based on the total weight of the pyrolysis gas stream.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis gas can have a C3 and/or C4 hydrocarbon content (including all hydrocarbons having 3 or 4 carbon atoms per molecule) in the range of 10 to 90 weight percent, 25 to 90 weight percent, or 25 to 80 weight percent, based on the total weight of the pyrolysis gas stream.
In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis gas can have a combined ethylene and propylene content of at least 25, at least 40, at least 50, at least 60, at least 70, or at least 75 weight percent, based on the total weight of the pyrolysis gas stream.
Turning to the pyrolysis residue, in an embodiment or in combination with any embodiment mentioned herein, the pyrolysis residue 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, or at least 85 weight percent of C20+ hydrocarbons based on the total weight of the pyrolysis residue. As used herein, “C20+ hydrocarbon” refers to hydrocarbon compounds containing at least 20 total carbons per molecule, and encompasses all olefins, paraffins, and isomers having that number of carbon atoms.
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the pyrolysis gas stream and/or pyrolysis residue stream may be routed to one or more other chemical processing facilities, including, for example, the cracking facility. As shown in
As shown in
Generally, the solvent extraction process exploits the different solubilities of the various components (e.g., aromatics and diolefins) of the pyrolysis oil stream in a solvent. The solvent extraction process generally involves placing the pyrolysis oil stream in contact with at least one extraction solvent that is either immiscible or only partially miscible with the pyrolysis oil stream. The solvent may be chosen so that it can preferentially dissolve or extract the desired components (e.g., aromatics and/or diolefins) from the pyrolysis oil stream. The two liquid phases that are then formed can be physically separated and the extract stream 28 (enriched in aromatics and/or diolefins) may be recovered and separated from the raffinate phase, usually by distillation. Solvent extraction may also be used to further separate out specific types of lighter aromatics (e.g., benzene) from heavier aromatics (e.g., toluene). Exemplary commercial solvent extraction systems that may be used as the separator 26 may include Sulfolane® by UQP, Udex™ by UOP, Tetra™ by UOP, Carom™ by UOP, Arosolvan® by Lurgi, Morphylex® by Krupp Kopper and IFP, and Formex® by Enichem.
An exemplary solvent extraction process and system 26 is depicted in
Alternatively, as shown in
As shown in
Generally, in certain embodiments, the pyrolysis oil stream may be separated into the extract stream 28 and the raffinate stream 30 via a solvent extraction process or an extractive distillation process. The extraction solvents used may include, for example, sulfolane, water, N-formylmorpholine, tetrahydrofurfuryl alcohol (THFA), sulfolane, furfural, tetraethylene glycol, dimethylsulfoxide, N-methyl-2-pyrrolidone, or combinations thereof.
The separator 26 shown in
The separator system 26 depicted 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, the feed stream into the separator 26 may comprise at least 10, at least 25, at least 50, at least 75, at least 90, at least 95, or at least 99 weight percent of the pyrolysis oil stream, based on the total weight of the feed stream. Additionally, or in the alternative, the feed stream into the separator 26 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 weight percent of the pyrolysis oil stream, based on the total weight of the feed stream.
In an embodiment or in combination with any embodiment mentioned herein, the feed stream into the separator 26 may comprise at least 10, at least 25, at least 50, at least 75, at least 90, at least 95, or at least 99 weight percent of the liquid product stream from the cracking facility, based on the total weight of the feed stream. Additionally, or in the alternative, the feed stream into the separator 26 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 weight percent of the liquid product stream from the cracking facility, based on the total weight of the feed stream.
As noted above, the extract stream 28 may be enriched in aromatics (e.g., benzene, toluene, ethyl benzene, styrene, and/or xylene) and diolefins (e.g., cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof), which have been derived from the pyrolysis oil stream.
In an embodiment or in combination with any embodiment mentioned herein, the extract stream 28 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, or at least 40 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, or not more than 65 weight percent of one or more aromatics, based on the total weight of the stream. Exemplary aromatics may include benzene, ethyl benzene, toluene, xylene, styrene, and/or derivatives thereof.
In an embodiment or in combination with any embodiment mentioned herein, the extract stream 28 may comprise at least 0.01, at least 0.05, at least 0.1, at least 0.5, at least 1, least 2, or least 3 weight percent and/or not more than 30, not more than 20, not more than 15, 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 0.5, or not more than 0.1 weight percent of one or more diolefins, based on the total weight of the stream. Exemplary diolefins may include cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof.
Although not depicted in
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the extract stream 28 may be separated into an aromatics stream and a diolefin stream. Any conventional separation technique may be used to separate the extract stream, such as extractive distillation, solvent extraction, or distillation. In such embodiments, the aromatics stream may be enriched in aromatics and depleted in diolefins (relative to the extract stream) and the diolefin stream may be enriched in diolefins and depleted in aromatics (relative to the extract stream). Additionally, in certain embodiments, at least a portion of the aromatics stream and/or the diolefin stream may be sold to downstream chemical processors for downstream processing. For example, at least a portion of the aromatics stream and/or the diolefin stream may be subjected to downstream processing to form chemical derivatives, polymers, fuels, and/or other hydrocarbons.
Turning back to
In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises 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 5, 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 of benzene, ethyl benzene, toluene, xylenes, styrene, and/or total diolefins, based on the total weight of the raffinate stream.
In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises at least 1, at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 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, or not more than 65 weight percent of cyclopentadiene and/or dicyclopentadiene, based on the total weight of the raffinate stream.
In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises 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 5, 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 of aromatics, such as benzene, ethyl benzene, toluene, xylenes, and/or styrene, based on the total weight of the raffinate stream.
In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises 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 5, 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 of diolefins, such as cyclopentadiene, dicycloplentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof, based on the total weight of the raffinate stream.
As shown in
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of one or more streams from the pyrolysis facility, including the raffinate stream 30 and/or the pyrolysis gas stream, may be introduced into a cracking facility. As used herein, the term “cracking” refers to breaking down complex organic molecules into simpler molecules by the breaking of carbon-carbon bonds. A “cracking facility” is a facility that includes all equipment, lines, and controls necessary to carry out cracking of a feedstock derived from waste plastic. A cracking facility can include one or more cracker furnaces 14, a quench system 16 for cooling the cracked products, a compression system, and a downstream separation zone including equipment used to process the effluent of the cracker furnace(s) 14. As used herein, the terms “cracker” and “cracking” are used interchangeably.
In general, the cracker facility may include a cracker furnace 14, a quench system 16, a compression system, and a separation zone downstream of the cracker furnace 14 for separating the furnace effluent into various end products, such as a recycle content olefin (r-olefin) stream. In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the raffinate stream 30 and/or the pyrolysis gas stream can be sent to the cracking facility. The raffinate stream 30 may be introduced into an inlet of the cracker furnace 14, while the pyrolysis gas stream can be introduced into a location upstream or downstream of the furnace. The effluent from the cracker furnace 14 may be separated into gas products and liquid products in the downstream separator, as shown in
In some embodiments, the cracker feed stream can include a hydrocarbon feed other than the pyrolysis gas and the raffinate stream in an amount of from 5 to 95 weight percent, 10 to 90 weight percent, or 15 to 85 weight percent, based on the total weight of the cracker feed.
In an embodiment or in combination with any embodiment mentioned herein, the cracker facility may comprise a single cracking furnace, or it can have at least 2, or at least 3, or at least 4, or at least 5, or at least 6, or at least 7, or at least 8 or more cracking furnaces operated in parallel. Any one or each furnace(s) may be gas cracker, or a liquid cracker, or a split furnace.
The cracker feed stream, along with the raffinate stream and/or pyrolysis gas, may pass through the cracking furnace, wherein the hydrocarbon components therein are thermally cracked to form lighter hydrocarbons, including olefins such as ethylene, propylene, and/or butadiene. The residence time of the cracker stream in the furnace can be in the range of from 0.15 to 2 seconds, 0.20 to 1.75 seconds, or 0.25 to 1.5 seconds.
The temperature of the cracked olefin-containing effluent withdrawn from the furnace outlet can be in the range of from 730 to 900° C., 750 to 875° C., or 750 to 850° C.
In an embodiment or in combination with any embodiment mentioned herein, the olefin-containing gas products stream withdrawn from the separator in the cracking facility (as shown in
Additionally, a liquid products stream, which is enriched in aromatics and diolefins, may be also recovered from the separator in the cracking facility as shown in
In an embodiment or in combination with any embodiment mentioned herein, the liquid products stream derived from cracking facility 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, or at least 40 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, or not more than 65 weight percent of one or more aromatics, based on the total weight of the stream. Exemplary aromatics may include benzene, ethyl benzene, toluene, xylene, styrene, and/or derivatives thereof.
In an embodiment or in combination with any embodiment mentioned herein, when introduced into the cracker facility, the pyrolysis gas stream may be introduced into the inlet of the cracker furnace 14, or all or a portion of the pyrolysis gas stream may be introduced downstream of the furnace outlet, at a location upstream of or within the separation zone of the cracker facility. When introduced into or upstream of the separation zone, the pyrolysis gas can be introduced upstream of the last stage of compression in the compressor, or prior to the inlet of at least one fractionation column in a fractionation section of the separator.
Upon exiting the cracker furnace outlet, the olefin-containing effluent stream may be cooled rapidly (e.g., quenched) in the quench system 16 in order to prevent production of large amounts of undesirable by-products and to minimize fouling in downstream equipment.
In an embodiment or in combination with any embodiment mentioned herein, at least a portion of one or more of the above streams may be introduced into one or more of the facilities shown in
As noted above, at least a portion of the liquid products stream from the cracking facility may be routed to the separator in the pyrolysis facility, so as to recover the aromatics and diolefins from this 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 “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.
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 “cracking” refers to breaking down complex organic molecules into simpler molecules by the breaking of carbon-carbon bonds.
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 “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, 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 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 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 “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 “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 “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 “plastic” may include any organic synthetic polymers that are solid at 25° C. and 1 atmosphere of pressure.
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 a feedstock of a biomass and/or a plastic material in solid or liquid form at elevated temperatures in an inert (i.e., substantially molecular 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 terms “pyrolysis gas” and “pygas” refer to a composition obtained from pyrolysis that is gaseous at 25° C. at 1 atm.
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 terms “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 terms “r-pyrolysis gas” or “r-pygas” refer to being or comprising a pyrolysis gas that is directly and/or indirectly derived from waste plastic.
As used herein, the terms “r-pyrolysis oil” or “r-pyoil” refer to being or comprising a pyrolysis oil that is directly and/or indirectly derived from waste plastic.
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, “downstream” means a target unit operation, vessel, or equipment that:
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.
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/US2023/064372 | 3/15/2023 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63269484 | Mar 2022 | US |
