Patent Application
20230203387
The present invention generally relates to systems and methods of processing pyrolysis oil (pyoil). More specifically, the present invention relates to system and methods for pre-treating pyoil to create a more stable pyoil product and/or a more desirable pyoil raw material for cracking.
Plastics are ubiquitous in industrial and domestic applications. While tons of plastics are produced every day, waste plastics have created serious environmental challenges due to their extremely long natural decomposition process. Thus, various processes for reuse and/or recycle plastics have been explored in the last few decades.
Pyrolysis of mixed plastics is a process that includes decomposing plastics at a high temperature to produce a pyoil. Pyoil can be used directly as a liquid fuel or further processed for producing chemicals of high value. However, pyoil produced from mixed plastics generally contains a substantial amount of highly reactive chemicals, resulting in fast aging of the pyoil and formation of gums during transportation and further processing steps. Hence, it is fairly common for pyoil to foul containers and/or chemical processing units in which it is handled and/or processed with trace oxygen presented therein.
In the context of the present invention, at least twenty embodiments are now described. Embodiment 1 is a method of processing pyrolysis oil (pyoil). The method includes the steps of treating the pyoil with an adsorbent and thereby removing gum and/or gum precursors from the pyoil to produce a purified pyoil; and cracking the purified pyoil under reaction conditions sufficient to produce olefins and aromatics. Embodiment 2 is the method of embodiment 1, wherein the treating step is further configured to increase stability of the pyoil. Embodiment 3 is the method of any of embodiments 1 and 2, wherein the treating step includes flowing the pyoil through an adsorbent under processing conditions sufficient to remove at least some of, one or more of: (a) oxygen containing compounds, (b) nitrogen containing compounds, (c) chlorine containing compounds, (d) polynuclear aromatics and heavy tails (C20+), (e) silicon containing compounds, and (f) heavy metals from the pyoil. Embodiment 4 is the method of embodiment 3, wherein the adsorbent is contained in a guard bed, a purification column, a stirring tank, a fluidized bed, or a combination thereof. Embodiment 5 is the method of any of embodiments 3 and 4, wherein the adsorbent contains an activated charcoal (carbon), a molecular sieve, a bleaching clay, a silica hydrogel, an ionic resin, a cured eggshell powder, or combinations thereof. Embodiment 6 is the method of embodiment 5, wherein the molecular sieve is configured to lighten the color of the pyoil, reduce total organic nitrogen, reduce density of the pyoil, reduce chlorinates concentration in the pyoil, reduce oxygenates of the pyoil, minimize the corrosion and/or fouling on downstream equipment, or combinations thereof. Embodiment 7 is the method of any of embodiments 5 and 6, wherein the molecular sieve contains K12[(AlO2)12(SiO2)12]·nH2O, Na12[(AlO2)12(SiO2)12]˜nH2O, Ca4.5[(AlO2)12(SiO2)12]·nH2O, Na86[(AlO2)86(SiO2)106]·nH2O, or combinations thereof. Embodiment 8 is the method of any of embodiments 5 to 7, wherein the molecular sieve has a pore size of 3 to 10 Å. Embodiment 9 is the method of any of embodiments 5 to 8, wherein the adsorbent has a surface area in a range of 10 to 8000 m2/g. Embodiment 10 is the method of any of embodiments 3 to 9, wherein the oxygen and/or nitrogen containing compounds include aliphatic acids, aromatic acids, nitriles, amines, aldehydes, aliphatic/cyclic ketones, cyclic amides, aliphatic/aromatic alcohols, diols, esters, ethers, aliphatic/cyclic chlorines, furans, indoles, quinolines, phenolic compound, indolic compounds, acidic compounds, alcohols, amines, or combinations thereof. Embodiment 11 is the method of embodiment 10, wherein the oxygen and/or nitrogen containing compounds include 2-heptadecanone, 2-pentanone, caprolactam, 3-heptanol, methyl (iso2), octadecanenitrile, oleanitrile, cyclopentanone, traidecanenitrile, heptanoic acid, doedecanophenone, 2-cyclopentenol, 1-butanol, benzoic acid, hexanenitrile, tridecanenitrile, 2-cyclopenten-1-one, 2-hydroxy-3-m, phenol, C5 substituted (iso2), 2-cyclopenten-1-one, 3-ethyl-2-hydro, or combinations thereof. Embodiment 12 is the method of any of embodiments 1 to 11, wherein the process conditions in the treating step include a processing temperature of 10 to 100° C. Embodiment 13 is the method of any of embodiments 1 to 12, wherein the process conditions in the treating step include a processing pressure of 0.1 to 10 bar. Embodiment 14 is the method of any of embodiments 1 to 13, wherein the adsorbent has substantially no or no impact on hydrocarbon cracking value of the pyoil. Embodiment 15 is the method of any of embodiments 1 to 14, wherein the cracking includes steam-cracking. Embodiment 16 is the method of embodiment 15, wherein the steam cracking is conducted at a cracking temperature of 750 to 900° C. Embodiment 17 is the method of any of embodiments 15 and 16, wherein the steam cracking is conducted at a residence time of 1 to 4000 ms. Embodiment 18 is the method of any of embodiments 1 to 17, further including the step of regenerating the adsorbent via thermal regeneration, thermal and vacuum regeneration, rinsing with strong acid or strong basic solutions, solvent rinsing of the adsorbent, or combinations thereof. Embodiment 19 is the method of any of embodiments 1 to 18, further including removing the adsorbent from the purified pyoil via settling, filtration, cyclone, or combinations thereof.
Embodiment 20 is a method of processing pyoil. The method includes the steps of treating the pyoil with one or more non-silica based adsorbents and thereby removing gum and/or gum precursors from the pyoil to produce a purified pyoil; and utilizing the purified pyoil as a liquid fuel.
Overall, while systems and methods for processing or storing pyoil derived from mixed plastics exist, the need for improvements in this field persists in light of at least the aforementioned drawbacks of conventional systems and methods.
A solution to at least some of the above-mentioned problems associated with the systems and methods of processing pyoil derived from plastics has been discovered. The solution resides in a method of processing pyoil comprising treating the pyrolysis oil with an adsorbent to (1) remove gum and/or gum precursors from the pyoil and/or (2) increase stability of the pyoil, thereby reducing fouling and corrosivity of purified pyoil. Furthermore, the purified pyoil after the treating step can be cracked to produce high value products including olefins and aromatics (e.g., BTX), increasing the value of the pyoil. Additionally, the pyoil can be obtained from mixed plastics, thereby reducing the pollution caused by plastics. The adsorbent can include materials with high surface areas (e.g., molecular sieves and activated charcoal) or specific active targets that target acidic or basic contaminants (e.g., ion exchange resin), which can significantly increase the adsorption efficiency for removing gum precursors and/or oxidants. Therefore, the disclosed methods provide a technical achievement over the conventional method for processing pyoil.
Embodiments of the invention include a method of processing pyoil. The method comprises treating the pyoil with an adsorbent and thereby removing gum and/or gum precursors from the pyoil to produce a purified pyoil. The method comprises cracking the purified pyoil under reaction conditions sufficient to produce olefins and aromatics.
Embodiments of the invention include a method of processing pyoil. The method comprises flowing the pyoil through an adsorbent under processing conditions sufficient to remove at least some of, one or more of: (a) oxygen containing compounds, (b) nitrogen containing compounds, (c) chlorine containing compounds, (d) polynuclear aromatics and heavy tails (C20+), (e) silicon containing compounds, and (f) heavy metals from the pyoil, and produce a purified pyoil. The method comprises cracking the purified pyoil under reaction conditions sufficient to produce olefins and aromatics.
Embodiments of the invention include a method of processing pyoil. The method comprises flowing the pyoil through a guard bed, a purification column, a fluidized bed, and/or a stirring tank comprising an adsorbent under processing conditions sufficient to remove at least some of, one or more of: (a) oxygen containing compounds, (b) nitrogen containing compounds, (c) chlorine containing compounds, (d) polynuclear aromatics and heavy tails (C20+), (e) silicon containing compounds, and (f) heavy metals from the pyoil, and produce a purified pyoil. The method comprises steam-cracking the purified pyoil under reaction conditions sufficient to produce olefins and aromatics.
Embodiments of the invention include a method of processing pyoil. The method comprises treating the pyoil with one or more non-silica based adsorbents and thereby removing gum and/or gum precursors from the pyoil to produce a purified pyoil. The method comprises using the purified pyoil as a liquid fuel.
The following includes definitions of various terms and phrases used throughout this specification.
The terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art. In one non-limiting embodiment the terms are defined to be within 10%, preferably, within 5%, more preferably, within 1%, and most preferably, within 0.5%.
The terms “wt. %”, “vol. %” or “mol. %” refer to a weight, volume, or molar percentage of a component, respectively, based on the total weight, the total volume, or the total moles of material that includes the component. In a non-limiting example, 10 moles of component in 100 moles of the material is 10 mol. % of component.
The term “substantially” and its variations are defined to include ranges within 10%, within 5%, within 1%, or within 0.5%.
The terms “inhibiting” or “reducing” or “preventing” or “avoiding” or any variation of these terms, when used in the claims and/or the specification, include any measurable decrease or complete inhibition to achieve a desired result.
The term “effective,” as that term is used in the specification and/or claims, means adequate to accomplish a desired, expected, or intended result.
The term “gum,” as that term is used in the specification and/or claims, means phased out solid and/or creamy and/or semisolids portion from liquid pyoil. In embodiments of the invention, “gum” can include components having an average molecular weight of 400 Dalton that are soluble or crash out of the solution and/or liquid. Many cracked gasolines, especially those unrefined, a thick resinous material deposited under certain conditions can include gum. For instance, on long standing in dark condition or diffused light condition, it is common that a semi-fluid material, known as “gum”, gradually accumulate as a brown, sticky mass at the bottom of the oil. Another example of “gum” can include that a dark brown, hard, and resinous residue that can be obtained by evaporation of a liquid product including a cracked gasoline and/or pyoil in a copper dish.
The term “stability,” as that term is used in the specification and/or claims, means pyoil composition is not altered over time by chemical reactions. In embodiments of the invention, “stability” can mean that there is limited or no reactivity of pyoil (treated by an adsorbent) due to cleaning/trapping of reactive substances by the adsorbent. As a result, substantially no or no further formation of gum or any other color changes occurred and properties remained unchanged for a longer period of time after purification.]
The use of the words “a” or “an” when used in conjunction with the term “comprising,” “including,” “containing,” or “having” in the claims or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”
The words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.
The process of the present invention can “comprise,” “consist essentially of,” or “consist of” particular ingredients, components, compositions, etc., disclosed throughout the specification.
The term “primarily,” as that term is used in the specification and/or claims, means greater than any of 50 wt. %, 50 mol. %, and 50 vol. %. For example, “primarily” may include 50.1 wt. % to 100 wt. % and all values and ranges there between, 50.1 mol. % to 100 mol. % and all values and ranges there between, or 50.1 vol. % to 100 vol. % and all values and ranges there between.
Other objects, features and advantages of the present invention will become apparent from the following figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific embodiments of the invention, are given by way of illustration only and are not meant to be limiting. Additionally, it is contemplated that changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In further embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any of the other embodiments. In further embodiments, additional features may be added to the specific embodiments described herein.
For a more complete understanding, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:
Currently, pyoil, especially pyoil derived from pyrolysis of plastics, has a high gum or gum precursor content, resulting in high gum formation, low stability, and high acidity of the pyoil. Thus, it is highly challenging to store, transport, and/or process pyoil in a chemical plant, resulting in pyoil often being directly burned as a fuel. The present invention provides a solution to at least some of these problems. The solution is premised on a method of processing pyoil. The method includes first treating the pyoil with an adsorbent to remove gum and/or gum precursors from the pyoil, thereby reducing the corrosivity and fouling risk of pyoil. Furthermore, by removing gum precursors, the stability of the pyoil can be greatly improved for storage, transportation, and further processing. Moreover, the purified pyoil produced by the treating step can be used in a cracking process to produce high value chemicals such as olefins, including light olefins (C2 to C4 olefins), C5 olefins, and BTX (benzene, toluene, and xylene). These and other non-limiting aspects of the present invention are discussed in further detail in the following sections.
In embodiments of the invention, the disclosed system can include a purification unit and a cracking unit. According to embodiments of the invention, the system is configured to facilitate production of high value chemicals from pyoil with reduced fouling and corrosion of cracking unit. With reference to
According to embodiments of the invention, system 100 includes purification unit 101 configured to (1) remove gum and/or gum precursors from pyoil of pyoil stream 11 and/or (2) increase stability of the pyoil to produce purified pyoil stream 12 comprising a purified pyoil. Pyoil stream 11 can include pyoil derived by pyrolysis of mixed plastics. In embodiments of the invention, purification unit 101 can include an adsorbent. The adsorbent comprises materials of surface areas configured to trap, adsorb, and/or remove at least some of, one or more of: (a) oxygen containing compounds, (b) nitrogen containing compounds, (c) chlorine containing compounds, (d) polynuclear aromatics and heavy tails (C20+), (e) silicon containing compounds, and (f) heavy metals from the pyoil of pyoil stream 11, thereby removing gum and/or gum precursors from the pyoil and increasing stability of the pyoil. In embodiments of the invention, the adsorbent is configured to further remove other heteroatom containing compounds that are not gum or gum precursors. The adsorbent, in embodiments of the invention, is configured to further remove other oxygen containing compounds, nitrogen containing compounds, chlorine containing compounds that are not gum or gum precursors.
In embodiments of the invention, the oxygen and/or nitrogen containing compounds can include aliphatic acids, aromatic acids, nitriles, amines, aldehydes, aliphatic/cyclic ketones, cyclic amides, aliphatic/aromatic alcohols, diols, esters, ethers, aliphatic/cyclic chlorines, furans, indoles, quinolines, phenolic compound, indolic compounds, acidic compounds, alcohols, amines, or combinations thereof. The oxygen and/or nitrogen containing compounds can include 2-heptadecanone, 2-pentanone, caprolactam, 3-heptanol, methyl (iso2), octadecanenitrile, oleanitrile, cyclopentanone, traidecanenitrile, heptanoic acid, doedecanophenone, 2-cyclopentenol, 1-butanol, benzoic acid, hexanenitrile, tridecanenitrile, 2-cyclopenten-1-one, 2-hydroxy-3-methyl-, phenol, C5 substituted (iso2), 2-cyclopenten-1-one, 3-ethyl-2-hydroxy-, or combinations thereof.
In embodiments of the invention, exemplary adsorbents of purification unit 101 can include an activated charcoal (carbon), a molecular sieve, a bleaching clay, a silica hydrogel, an ionic resin, a cured eggshell powder, and combinations thereof. Purification unit 101 can include a combination adsorbents, where the types of adsorbents are selected based on the species and concentration of compounds to be removed from the pyoil. The adsorbent can have a surface area in a range of 10 to 8000 m2/g and all ranges and values there between including ranges of 10 to 50 m2/g, 50 to 100 m2/g, 100 to 400 m2/g, 400 to 700 m2/g, 700 to 1000 m2/g, 1000 to 2000 m2/g, 2000 to 4000 m2/g, 4000 to 6000 m2/g, and 6000 to 8000 m2/g. According to embodiments of the invention, the adsorbent of purification 101 comprises a molecular sieve and the molecular sieve is configured to lighten the color of the pyoil, reduce total organic nitrogen of the pyoil, reduce density of the pyoil, reduce chlorinates concentration in the pyoil, reduce oxygenates of the pyoil, minimize the corrosion and/or fouling on downstream equipment, or combinations thereof. In embodiments of the invention, the molecular sieve includes K12 [(AlO2)12(SiO2)12]·nH2O, Na12[(AlO2)12(SiO2)12]·nH2O, Ca4.5[(Al02)12(SiO2)12]·nH2O, Na86[(AlO2)86(SiO2)106]·nH2O, or combinations thereof. The molecular sieve can have a pore size of 3 to 10 Å and all ranges and values there between including ranges of 3 to 4 Å, 4 to 5 Å, 5 to 6 Å, 6 to 7 Å, 7 to 8 Å, 8 to 9 Å, and 9 to 10 Å. The molecular sieve can be in a form of granules, flakes, beads, powder, or combinations thereof.
In embodiments of the invention, the adsorbent includes an activated charcoal (carbon). The activated charcoal may have a pore size in a range of 1 to 100 Å. The activated charcoal may have a surface area of 10 to 8000 m2/g. In embodiments of the invention, purification unit 101 can include a guard bed, a purification column, a fluidized bed, a stirring tank, or a combinations thereof. The adsorbent in purification unit 101 may form a fixed bed and/or a fluidized bed, or be dispersed in a stirring tank.
According to embodiments of the invention, an outlet of purification unit 101 is in fluid communication with cracking unit 102 such that purified pyoil stream 12 flows from purification unit 101 to cracking unit 102. In embodiments of the invention, cracking unit 102 may be configured to crack the purified pyoil of purified pyoil stream 12 to produce product stream 13 comprising olefins and aromatics. In embodiments of the invention, cracking unit 102 can include a steam cracker, a hydrocracker, and/or a fluid catalytic cracker. In embodiments of the invention, cracking unit 102 can include a hydrotreater installed upstream to the a steam cracker, a hydrocracker, and/or a fluid catalytic cracker configured to hydrotreat the purified pyoil before it is flowed in the a steam cracker, a hydrocracker, and/or a fluid catalytic cracker. Product stream 13 may include light olefins and BTX (benzene, toluene, and xylene).
In embodiments of the invention, purification unit 101 includes an adsorbent that is in powder form and system 100 can include a separation unit installed between purification unit 101 and cracking unit 102. The separation unit can be configured to separate the adsorbent from purified pyoil stream 12 before purified pyoil stream 12 is flowed into cracking unit 102. In embodiments of the invention, the separation unit can include a settling unit, a membrane, a filtration unit, a cyclone unit, or combinations thereof.
According to embodiments of the invention, system 100 can include an adsorbent regeneration unit configured to regenerate adsorbent (saturated or partially saturated) from purification unit 101 to remove the gum and/or gum precursors and produce regenerated adsorbent. As an alternative or in addition to an adsorbent regeneration unit, the absorbent (saturated or partially saturated) can be regenerated in purification unit 101 when purification unit 101 is not used for treating pyoil stream 11. In embodiments of the invention, at least a portion of saturated or partially saturated adsorbent of purification unit 101 can be discarded without regeneration.
A method of processing pyoil has been discovered. The method can reduce fouling and/or corrosion during storage and/or chemical production process caused by pyoil compared to conventional methods. As shown in
In embodiments of the invention, treating at block 201 can include treating the pyoil by flowing it through the adsorbent of purification unit 101 under processing conditions sufficient to remove at least some of, one or more of: (a) oxygen containing compounds, (b) nitrogen containing compounds, (c) chlorine containing compounds, (d) polynuclear aromatics and heavy tails (C20+), (e) silicon containing compounds (e.g., siloxanes), and (f) heavy metals from the pyoil. In embodiments of the invention, the adsorbent is configured to trap, adsorb, and/or adsorb the (a) oxygen containing compounds, (b) nitrogen containing compounds, (c) chlorine containing compounds, (d) polynuclear aromatics and heavy tails (C20+), (e) silicon containing compounds, and (f) heavy metals. In embodiments of the invention, the processing conditions for the treating step at block 201 include a temperature of 10 to 100° C. and all ranges and values there between including ranges of 10 to 20° C., 20 to 30° C., 30 to 40° C., 40 to 50° C., 50 to 60° C., 60 to 70° C., 70 to 80° C., 80 to 90° C., and 90 to 100° C. The processing conditions for the treating step at block 201 can further include a pressure of 0.1 to 10 bar. In embodiments of the invention, adsorbents of purification unit 101 can include an activated charcoal (carbon), a molecular sieve, a bleaching clay, a silica hydrogel, an ionic resin, a cured eggshell powder, and combinations thereof. Purification unit 101 can include a combination adsorbents, where the types of adsorbents are selected based on the species and concentration of compounds to be removed from the pyoil. In embodiments of the invention, the adsorbent of purification unit 101 is configured in a fixed bed and the processing conditions for the treating step at block 201 can further include a weight hourly space velocity of 0.1 to 10 hr−1 and all ranges and values there between including ranges of 0.1 to 0.5 h−1, 0.5 to 1 hr−1, 1 to 2 hr−1, 2 to 4 hr−1, 4 to 6 hr−1, 6 to 8 hr−1, and 8 to 10 hr−1. In embodiments of the invention, the adsorbent of purification unit 101 is dispersed in a stirring tank and the processing conditions for the treating step at block 201 can further include a mixing time of 1 minute to 10 hours and all ranges and values there between including 1 to 10 minutes, 10 to 30 minutes, 30 minutes to 1 hour, 1 to 2 hour, 2 to 3 hour, 3 to 4 hour, 4 to 5 hour, 5 to 6 hour, 6 to 7 hour, 7 to 8 hour, 8 to 9 hour, and 9 to 10 hour. In embodiments of the invention, pyoil produced by pyrolysis of plastics may be directly flowed through the adsorbent without other pretreatment (e.g., alkali rinsing, etc.). In embodiments of the invention, the adsorbent of purification unit 101 used at block 201 may not contain any added chemicals.
In embodiments of the invention, the treating at block 201 is further configured to reduce dark color of the pyoil, reduce total organic nitrogen, reduce density of the pyoil, reduce chlorinates concentration in the pyoil, reduce oxygenates of the pyoil, minimize the corrosion and/or fouling on downstream equipment, or combinations thereof.
In embodiments of the invention, purified pyoil stream 12 includes 0.01 to 2.5 wt. % oxygen containing compounds, 0.01 to 0.1 wt. % nitrogen containing compounds, 0.0001 to 0.01 wt. % chlorine containing compounds, 0.5 to 10 wt. % polynuclear aromatics and heavy tails (C20+), 0.0001 to 0.01 wt. % silicon containing compounds, and/or 0.0001 to 0.01 wt. % heavy metals.
According to embodiments of the invention, as shown in block 202, method 200 includes optionally removing the adsorbent from purified pyoil stream 12 in a separation unit when purification unit 101 includes powder formed adsorbent. In embodiments of the invention, the removing at block 202 includes settling the adsorbent from purified pyoil stream 12, filtering purified pyoil stream 12, and/or processing purified pyoil stream 12 in a cyclone unit and/or a membrane unit.
According to embodiments of the invention, as shown in block 203, method 200 includes cracking, in cracking unit 102, the purified pyoil of purified pyoil stream 12 under reaction conditions sufficient to produce olefins and aromatics in product stream 13. In embodiments of the invention, the reaction conditions at block 203 include reaction temperature of 750 to 900° C. and a residence time of 1 to 4000 ms. In embodiments of the invention, the cracking at block 203 includes a steam cracking process, a fluid catalytic cracking process, a hydrocracking process, and/or a hydrotreating process. In embodiments of the invention, product stream 13 comprises 10 to 50 wt. % olefins.
According to embodiments of the invention, as shown in block 204, method 200 includes regenerating partially saturated or saturated adsorbent from purification unit 101 to produce regenerated adsorbent. In embodiments of the invention, the regenerating at block 204 can include burning the saturated or saturated adsorbent (thermal regeneration), vacuum and thermal regeneration, rinsing with strong acid or strong basic solution, and/or rinsing with polar organic solvent (e.g., tetrahydrofuran (THF)). In embodiments of the invention, at least some of the saturated or saturated adsorbent can be discarded without regeneration.
Although embodiments of the present invention have been described with reference to blocks of
The systems and processes described herein can also include various equipment that is not shown and is known to one of skill in the art of chemical processing. For example, some controllers, piping, computers, valves, pumps, heaters, thermocouples, pressure indicators, mixers, heat exchangers, and the like may not be shown.
As part of the disclosure of the present invention, specific examples are included below. The examples are for illustrative purposes only and are not intended to limit the invention. Those of ordinary skill in the art will readily recognize parameters that can be changed or modified to yield essentially the same results.
About 0.1 to 2 g of various adsorbent materials including molecular sieves and active charcoals etc., were added to the 10 mL of pyoil in 20 mL vials. The mixture was kept for a few days and gum deposits were observed.
A molecular sieve and air purging (He, N2, Air) were employed to treat pyoil, which was then compared to the untreated control. Results shown in
In
Several commercially available molecular sieves with different composition (K12 [(AlO2)12(SiO2)12]·nH2O; Na12[(AlO2)12(SiO2)12]·nH2O; Ca4.5[(AlO2)12(SiO2)12]·nH2O; Na86[(AlO2)86(SiO2)106]·nH2O) and porosity (3-10 Angstroms) were tested against N2 purged and blank pyoil samples as shown in
Results clearly indicate that most of the tested molecular sieves were effective in reducing gum formation. Similar to the molecular sieve, active charcoal also confirmed reduction of gum formation as shown in
About 0.1 to 2 g of various adsorbent materials including molecular sieves and active charcoals etc., were added to the 10 mL of pyoil in 20 mL vials. The mixture was kept for a specific period. The samples were tested for changes in color, changes in total organic nitrogen and oxygen containing compounds. The color changes were checked by visual inspection and by grey scale and RGB % analysis. Density was measured by gravimetric measurement against specific volume. The chlorinated species were detected and quantified by a GC×GC-HRMS system. Total organic nitrogen contents were measured by an isocratic GC-NCD system. Measurement of oxygenates were assessed by a comprehensive GC×GC-HRMS system. Pyoil oxygenates were measured by direct injection of pyoil, whereas molecular sieve/active charcoal trapped components were measured by extracting those by tetrahydrofuran, followed by injecting to GC×GC.
Experiments on different types of molecular sieves revealed different efficacy levels on reducing the darkness of the pyoil (
Quantitative analysis of grey scale for amount dependent effect on the pyoil color further justifies the same (
The results further imply that the microporous molecular sieves and mesoporous active charcoals absorb different classes of compounds with varied affinity.
Reduction of total organic nitrogen: As shown in
Reduction of density: As shown in
Detailed hydrocarbon group type analysis (PINA) reveals that both activated charcoal and molecular sieve reduced the heavier hydrocarbons, where the reduction was significantly higher in case of active charcoal treatment (
Reduction of chlorinates: Speciation of chlorinated compounds clearly revealed that treatment of both the molecular sieve and active charcoal resulted in decreasing chlorinated compounds. As shown in a few of the representative chlorinated species in
Reduction of oxygenates: Comprehensive GC×GC-HRMS analysis reveals that compared to untreated pyoil, pyoil treated with the molecular sieve and active charcoal contain significantly lower amount of oxygenates than the control. In-depth analysis clearly indicated that carboxylic acids, phenols, ketones, aldehydes are the main contributors of oxygenates present in the pyoil which are significantly eliminated from the treated pyoil. Though active charcoal removed significant amount of oxygenates, a portion of carboxylic acids were remained in treated pyoil. In contrast, active charcoal treated pyoil revealed a significant reduction of di-/poly-aromatic compounds compared to molecular sieves.
Further in depth analysis of heteroatoms clearly indicated a significant decrease for majority of the unwanted heteroatoms up to 30 fold (active charcoal) or 140 fold (molecular sieve) decrease, even decreased down to a not detectable limit (See Tables 1, 2, and 3).
Further analysis of treated molecular sieves and active charcoal by extracting the trapped and/or adsorbed components by tetrahydrofuran reveals that molecular sieves mainly trapped oxygenates with residual long chains paraffinic hydrocarbons, while active charcoal trapped and/or adsorbed both oxygenates and di-/poly-aromatic compounds along with residual paraffinic hydrocarbons. This result corroborates the findings on varied RGB % for molecular sieve and active charcoal shown in
Although embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the above disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.
This application claims the benefit of priority of U.S. Provisional Patent Application No. 63/039,868, filed Jun. 16, 2020, which is hereby incorporated by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/055115 | 6/10/2021 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63039868 | Jun 2020 | US |
