Continuous catalytic system for upcycling plastic waste to aromatics

Abstract

An upcycling system for converting plastic waste to value-added aromatic products and process of using same. The system includes a pyrolysis reactor and a catalytic aromatization reactor. Catalysts can be used to convert the plastic waste, for example marine plastic waste, into aromatic products such as benzene, toluene and / or xylene.

Description

Attorney Docket No.: JHU -44209.601CONTINUOUS CATALYTIC SYSTEM FOR UPCYCLING PLASTIC WASTE TO AROMATICSGOVERNMENT SUPPORT CLAUSE

[0001] This invention was made with Government support under grant no. DE-AR0001365, awarded by the U.S. Department of Energy. The Government has certain rights in the invention.CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 778,462, filed March 27, 2025, the contents of which are incorporated herein by reference in its entirety.BACKGROUND

[0003] Polymers are irreplaceable in the global economy, with a myriad of uses in packaging, construction, transportation, electronics, and health-care industries. Many of these applications rely on plastics as inexpensive disposable materials, which are nonetheless often precisely constructed to confer desired properties essential for the targeted function. Their massive-scale manufacture, single-use function, long lifetimes, slow decomposition rates, and disruption of sensitive ecosystems, however, have created a crisis of plastics waste.

[0004] In light of both the large drain on global resources and the massive amount of waste material generated, plastics represent a tremendous and as-yet-untapped domestic resource for the production of chemicals and new materials. Efficient technologies for extracting this value from discarded polymers would be equivalent to recovering about 3.5 billion barrels of oil each year and could create entirely new industries. Currently, most of the stored energy in plastics is irreversibly lost into landfills that are overflowing throughout our planet. While physical recycling is desirable and widespread in many areas for a wide range of materials, it is most effective for recovering glass, paper, and metals such as aluminum. Recycling, to date, has not been able to efficiently and cleanly recoup the inherent value in plastics, especially low-density polyethylene (plastic bags), polypropylene, and polystyrene. The syntheses of many virgin plastics are currently less expensive than creating quality recycled materials, because plastics are made on a large scale in centralized plants, from inexpensive monomers such as ethylene, in processes that are tightly integrated into commodity chemical production. As a result, many plastics are just burned as fuelAttorney Docket No.: JHU -44209.601or inefficiently reprocessed to manufacture lower-value materials (known as downcycling), resulting in minimal economic incentives for waste recovery, sorting, and processing.

[0005] Unfortunately, many plastics are not recycled and end up in the oceans. Some reports state that between 75 and 199 million tons of plastic is polluting our oceans. Rather than evenly dispersing in the oceans, plastics tend to concentrate in one of five gyres. Current estimates of the total size of the northern pacific gyre, the largest gyre, is that it covers more than 15.000,000 square kilometers. In addition, these plastics are broken down into small pieces by ultraviolet light and fluid power. These plastics and microplastics, which are tens of microns to several millimeters in size, are accidentally introduced into the body of fish and other aquatic organisms as food. It has been reported that some marine organisms die as a result. In addition, microplastics may have harmful substances attached to them, and there are concerns that eating fish that contain such microplastics may have an enormous impact on human health.

[0006] Chemical upcycling, an emerging alternative to the classical recycling approach, would use plastic waste as a feedstock for the synthesis of value-added chemicals and materials. Disadvantageous^, most plastic collected today is not deemed suitable for upcycling due, in part, to the variability of the incoming plastic stream. The sources of the variability include the mixing of different types of plastics, the degree of degradation associated with reprocessing plastics, and the presence of low molecular weight compounds.

[0007] There continues to be a need for a system and process that can upcycle plastic waste, wherein the plastic waste is converted to value-added aromatic products such as benzene, toluene, and xylene (BTX).SUMMARY

[0008] In some aspects, a system for upcycling plastic waste to produce aromatic compounds is described, said system comprising:at least one pyrolysis reactor;at least one condenser;at least one catalytic aromatization reactor; andat least one gas-liquid flash separator.

[0009] In some other aspects, a method of upcycling plastic waste to produce at least one aromatic compound is described, said method comprising:Attorney Docket No.: JHU -44209.601introducing plastic waste and a carrier gas to at least one pyrolysis reactor to pyrolyze the plastic waste into a pyrolysis product;moving the pyrolysis product to at least one condenser to separate light hydrocarbons from heavy hydrocarbons;moving the light hydrocarbons to at least one catalytic aromatization reactor to convert at least a fraction of the light hydrocarbons into at least one aromatic compound; andmoving a stream comprising the at least one aromatic compound to at least one gasliquid flash separator to separate the at least one aromatic compound from at least one gas selected from the group consisting of C1-C4 hydrocarbons, hydrogen gas, and a combination thereof.[00101 Other aspects, features and advantages of the invention will be more fully apparent from the ensuing disclosure and appended claims.BRIEF DESCRIPTION OF THE FIGURES

[0011] FIG. 1. An embodiment of the material stream of the continuous tandem pyrolysis and catalytic aromatization system described herein.

[0012] FIG. 2. An embodiment of a plastic granulation system and process thereof.

[0013] FIG. 3. An embodiment of a heat integration system of the upcycling system described herein.

[0014] FIG. 4. The hydrocarbon output when the at least one pyrolysis reactor comprises a halloysite catalyst and sand.

[0015] FIG. 5. An illustration of the halloysite structure.DETAILED DESCRIPTION OF THE DISCLOSURE

[0016] Although the claimed subject matter will be described in terms of certain embodiments, other embodiments, including embodiments that do not provide all of the benefits and features set forth herein, are within the scope of this disclosure as well. Various structural and parameter changes may be made without departing from the scope of this disclosure.DefinitionsAttorney Docket No.: JHU -44209.601[0017| Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Preferred methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0018] ‘ ‘About” and “approximately” are used to provide flexibility to a numerical range endpoint by providing that a given value may be “slightly above” or “slightly below” the endpoint without affecting the desired result, for example, + / - 5%.

[0019] The phrase “in one embodiment” or “in some embodiments” as used herein does not necessarily refer to the same embodiment, though it may. Furthermore, the phrase “in another embodiment” as used herein does not necessarily refer to a different embodiment, although it may. Thus, as described below, various embodiments of the invention may be readily combined, without departing from the scope or spirit of the invention.

[0020] The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms “a,” “and” and “the” include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments “comprising,” “consisting of’ and “consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not.

[0021] For the recitation of numeric ranges herein, each intervening number there between with the same degree of precision is explicitly contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the number 6.0, 6.1, 6.2, 6.3. 6.4, 6.5. 6.6, 6.7, 6.8. 6.9, and 7.0 are explicitly contemplated.

[0022] As used herein, a “system” refers to a plurality of real and / or abstract elements operating together for a common purpose. In some embodiments, a “system” is an integrated assemblage of hardware and / or software elements. In some embodiments, each component of the system interacts with one or more other elements and / or is related to one or more other elements. In some embodiments, a system refers to a combination of components and software for controlling and directing methods.Attorney Docket No.: JHU -44209.601[0023| As used herein, the terms “aromatics” or “aromatic compound” are used to refer to a hydrocarbon compound or compounds comprising one or more aromatic groups such as, for example, single aromatic ring systems (e.g., benzyl, phenyl, etc.) and fused polycyclic aromatic ring systems (e.g. naphthyl, 1,2,3,4-tetrahydronaphthyl, etc.). Examples of aromatic compounds include, but are not limited to, benzene, toluene, indane, indene, 2-ethyl toluene, 3-ethyl toluene, 4-ethyl toluene, trimethyl benzene (e.g.. 1, 3, 5-trimethyl benzene. 1, 2, 4-trimethyl benzene, 1.2,3-trimethyl benzene, etc.), ethylbenzene, styrene, cumene, methylbenzene, propylbenzene, xylenes (e.g., p-xylene, m-xylene, o-xylene, etc.), naphthalene, methyl-naphthalene (e.g., 1-methyl naphthalene, anthracene, 9.10-dimethylanthracene, pyrene, phenanthrene, dimethyl-naphthalene (e.g., 1,5 -dimethylnaphthalene, 1,6-dimethylnaphthalene, 2,5-dimethylnaphthalene, etc.), ethylnaphthalene, hydrindene, methyl-hydrindene, and dymethyl-hydrindene. Single-ring and / or higher ring aromatics may also be produced in some embodiments.

[0024] As defined herein, an “aliphatic compound” includes linear or branched alkanes, alkenes or alkynes. As the aliphatic compound, an alkane, alkene or alkyne having 2 to 20 carbon atoms, 2 to 16 carbon atoms, 2 to 12 carbon atoms, 2 to 8 carbon atoms or 2 to 4 carbon atoms is contemplated. The alkane, alkene or alkyne may be optionally substituted by one or more substituents.

[0025] The terms “plastics” and “polymers” are used interchangeably herein. A polymer is a carbon-based (at least 50 mass % C) material chiefly made up of repeating units and having a number average molecular weight of at least 100, typically greater than 1000 or greater than 10,000.

[0026] The term “fluidized bed reactor” is given its conventional meaning in the art and is used to refer to reactors comprising a vessel that can contain a granular solid material (e.g., silica particles, catalyst particles, etc.), in which a fluid (e.g., a gas or a liquid) is passed through the granular solid material at velocities sufficiently high as to suspend the solid material and cause it to behave as though it were a fluid.

[0027] The term “plug flow reactor,” also known as tubular reactors or continuous tubular reactors, is used to refer to reactors wherein reactants continuously flow through a tube or pipe as if they were a "plug" of fluid, with no back-mixing between different portions of the fluid, and products exit the reactor. The reactor contents are not continuously stirred but instead as the plug of fluid flows through the tube or pipe, reactants are converted to products. The interior surfaceAttorney Docket No.: JHU -44209.601of the reactor comprises catalytically active surfaces and the chemical reaction occurs within the tube or pipe of the plug-flow reactor.

[0028] As used herein, an “inert gas” includes, but is not limited to, nitrogen, helium, argon, neon, xenon, krypton, and radon.

[0029] As used herein, a “flare system” is a combustion device used to bum off flammable gases. Flare systems are well known in the art.

[0030] The term “yield” is used herein to refer to the amount of a product flowing out of a reactor divided by the amount of reactant flowing into the reactor, usually expressed as a percentage or fraction. Yields are often calculated on a mass basis or on the basis of a particular feed component. Mass yield is the mass of a particular product divided by the weight of feed used to prepare that product. For example, if 500 grams of polymer is fed to a reactor and 45 grams of benzene is produced, the mass yield of benzene would be 45 / 500=9% benzene.

[0031] The term “plastic waste,” as used herein, includes at least one of the major thermoplastic resins such as polyethylene (low density, linear low density, and high density), polypropylene, polyethylene terephthalate, polystyrene, and polyvinyl chloride. It should be appreciated that the plastic waste can include terrestrial plastic waste, for example as collected by recycling facilities, or marine plastic waste, for example, floating marine plastic waste or plastic waste collected from the bottom of a body of water. Methods of collection of marine plastic waste are known in the art.

[0032] As used herein, “light hydrocarbons” have a boiling point less than about 250°C, while “heavy hydrocarbons” have a boiling point more than about 250°C. The term “hydrocarbon” is understood to mean a class of compounds containing hydrogen bound to carbon, and encompasses (i) saturated hydrocarbon compounds; (ii) unsaturated hydrocarbon compounds; and (iii) mixtures of hydrocarbon compounds (saturated and / or unsaturated), including mixtures of hydrocarbon compounds having different values of n, i.e. differing carbon numbers. In some embodiments, the hydrocarbon compounds comprise a Cl-6 alkyl group, a C2-6 alkenyl group, a C2-6 alkynyl group, a C3-10 cycloalkyl group, a C3-10 cycloalkenyl group, a C6-14 aryl group or a C7-16 aralkyl group.

[0033] As used herein, “halloysite” corresponds to the aluminosilicate clay mineral with a hollow nanotubular structure and having the formula Ah(Si2O5)(OH)4. Halloysite is a layered structure comprising siloxane layers and gibbsite-like layers containing aluminum ions and OH groups. Halloysite has two different polymorphs; a hydrated one and a dehydrated oneAttorney Docket No.: JHU -44209.601(metahalloysite), wherein the latter is characterized by having reduced interlayer spacing relative to the former. An illustrative depiction of a halloysite structure is shown in FIG. 5, showing an external siloxane surface, an internal aluminal surface, and the layers. It should be appreciated that the term “halloysite” includes aluminosilicate clay minerals that are “substantially halloysitic,” for example, wherein ionic substitution has occurred wherein at least one ion of the halloysite crystal lattice has been replaced by a different ion having the same charge and approximately the same size. It should be appreciated that the substantially halloysitic material is also a layered structure comprising siloxane layers and gibbsite-like layers containing aluminum ions and OH groups and can be used as the catalytic material in the system and method described herein. It should be appreciated that the ionic substitution to yield a substantially halloysitic material is not the same as intercalation, as described herein.

[0034] As used herein, “at least a fraction of” corresponds to any amount between about 1% and about 100%, for example, greater than about 10%, greater than about 20%, greater than about 30%, greater than about 40%, greater than about 50%, greater than about 60%, greater than about 70%, greater than about 80%, greater than about 90%, greater than about 95%, greater than about 98%, or greater than about 99%, of the total amount of cited material.

[0035] Broadly, the present invention relates to a continuous catalytic system for producing aromatics including, but not limited to, benzene, toluene, and xylene (BTX) from plastic waste. In some embodiments, the system and methods comprise the use of a tandem pyrolysis and catalytic aromatization system (hereinafter “the upcycling system”) which includes several subsystems including: (1) a nitrogen-to-byproduct carrier gas system, (2) a byproduct recycling system, (3) optionally a heat integration system, and (4) optionally, a plastic granulation system. Under steady state conditions, the upcycling system is able to achieve an overall BTX yield of greater than 85 wt%.

[0036] Referring now to FIG. 1, plastic waste is fed into a fluidized bed with a carrier gas to the Pyrolysis reactor (Rl) containing a mixture of heating medium, a pyrolysis catalyst, or both heating medium and pyrolysis catalyst, to pyrolyze the plastic into its vapor. In some embodiments, the heating medium comprises sand. In some embodiments, the plastic waste is processed in the pretreatment step according to FIG. 2 (described below) prior to feeding into the fluidized bed together with the carrier gas to the Rl reactor containing a mixture of the heating medium and / or the catalyst to pyrolyze the plastic into its vapor. In some embodiments, Rl is operated at aboutAttorney Docket No.: JHU -44209.601400-500°C. In some embodiments, a carrier gas is introduced to R1. During start-up, the carrier gas 3 will initially be an externally-provided gas comprising a mixture of about 1-10% H2 in N2 at a volumetric flow x, represented by line 2. Once the upcycling system is in operation, a portion of the gas produced by the upcycling system, comprising C1-C4 and H2 gas, is recycled via line 11 and the carrier gas 3 becomes a mixture of the recycled gas 11 mixed with some externally-provided gas 2, such that the carrier gas 3 entering R1 has substantially the same volumetric flow x. In some embodiments, once a steady state is achieved, none of the externally-provided gas 2 is required for the carrier gas 3 to reach substantially the same volumetric flow x entering Rl.

[0037] Following pyrolysis in Rl, the pyrolysis product comprising light hydrocarbons and heavy hydrocarbons is moved to a condenser (C), which is maintained at a temperature of less than about 250°C. In some embodiments, the light hydrocarbons having a boiling point less than about 250°C leave the condenser via line 6 and enters the catalytic aromatization reactor (R2). In some embodiments, the heavy hydrocarbons having a boiling point of greater than about 250°C are recycled back into the pyrolysis reactor (Rl) via line 5 for additional pyrolysis. The light hydrocarbons in the catalytic aromatization reactor (R2) are heated to temperature of about 550-700°C. In some embodiments, the temperature of heating in R2 is about 550°C to about 600°C, or about 600°C to about 650°C, or about 650°C to about 700°C. In some embodiments, at least a fraction of the light hydrocarbons are converted to at least one aromatic compound in R2. The catalytic aromatization product comprising the at least one aromatic compound is cooled down to about-20°C to about 2 °C, or about the freezing point of water, at 1 bar and is sent to the gas-liquid flash separator (F). The temperature in the flash separator is maintained at about -20°C to 2°C at pressure ranging from 1-10 bar. Gas, comprising C1-C4 and / or H2 gas, leaving F is split in a splitter (S) with about 5-25% being purged to line 10 and the remainder sent for recycling via line 11. The purging stream is then proceeded into the flare system. The liquid fraction of F, represented by line 9, comprises the at least one aromatic compound, for example BTX, and optionally other aromatics and aliphatic hydrocarbons. The liquid fraction F can be collected and further processed as understood by the person skilled in the art.

[0038] In some embodiments, plastic waste is “pretreated” by granulating the plastic waste into pellets, prior to introduction to the pyrolysis reactor of the upcycling system of FIG. 1. In some embodiments, the pellets have been granulated such that they have a generalized size of about 1-5Attorney Docket No.: JHU -44209.601mm. Tt should be appreciated by the skilled artisan that the plastic waste can be granulated into pellets using any known system and method known in the art.

[0039] An embodiment of a plastic granulation system is illustrated in FIG. 2. The waste plastic stream pretreatment as shown in FIG. 2 starts with shredding the plastic in Shredder 1 (SRI). Unshredded plastic is recycled back to the SRI unit via line 22. The plastic flake generated in SRI is moved via line 23 to the washing system (WS) for washing with water. In some embodiments, the plastic flakes are washed and rinsed one time, two times, three times, four times, five times, or more. The washed plastic flakes then separated from the wastewater. In some embodiments, the washed plastic flakes are separated from the wastewater by taking advantage of the different densities of the plastic relative to the water. The wastewater is then sent to the water treatment system (WT) via line 24 and the treated water can be recycled via line 25 for reuse in the washing process. Systems and methods of water treatment are well known in the art. The wet plastic is moved via line 26 to the drying unit (DR) and dried in a dryer by contacting the wet plastic with hot dry air. Dried flakes of plastic are then moved to a Melting Unit (MT) via line 27, wherein the MT comprises a vacuum or inert atmosphere oven which is heated to about 100-150°C to melt the plastic into bigger aggregates. The plastic aggregates are then sent to Shredder 2 (SR2) via line 28 for shredding and the shredded plastic from SR2 is sent to a screener (SC) via line 29 to collect the pellet size of plastic with the size of about 1-5 mm. The larger fractions of pellets are recycled to the SR2 via line 30 to increase the overall yield of the desired plastic size. The plastic pellets having the desired size is then fed, via line 1, into the pyrolysis reactor (Rl) of FIG. 1.

[0040] In some other embodiments, plastic waste is not granulated into pellets prior to introduction to the upcycling system.

[0041] In some embodiments, the upcycling system further comprises a heat integration system, for example as illustrated in FIG. 3, wherein heat is recycled and reused in the upcycling system. For example, in some embodiments, stream 12 has a temperature in a range from about 550-700°C and is directed from R2 to HE3 to heat up line 6 from less than 250°C to 500-600°C. In some embodiments, stream 12 leaving HE3 feeds HE1 to heat up the carrier gas in line 3 from room temperature to about 200-250°C. The insertion of heat to HE3 and HE1 assists HE4 and HE2, respectively. In some embodiments, the temperature of stream 13 after passing HE3 and HE1 would be about 100-150°C. Stream 13 enters HE5, which comprises cooling means to cool down the gas in stream 13 further such that the temperature of stream 14 is in a range from about -20°CAttorney Docket No.: JHU -44209.601to about 2°C, or about the freezing point of water. Advantageously, using the heat integration system described herein, the heat duty of HE2 and HE4 to achieve their target temperature at 400-500°C and 550-700°C, respectively, is minimized.

[0042] In some embodiments, the upcycling system described herein does not include the use of a plug-flow reactor or a fluidized bed reactor.

[0043] In some embodiments, the pyrolysis catalyst in the pyrolysis reactor includes an alumino-silicate material including, but not limited to, amorphous silica-alumina, kaolinite, halloysite, bentonite, and montmorillonite. Halloysite and substantially halloysitic materials are particularly advantageous for catalytic hydrocracking in a pyrolysis reactor because of the nanotubular nature of the material, while also being highly stable, resistant against most organic solvents, and abundantly, and inexpensively, available. In some embodiments, the hollow interior of the nanotubes of halloysite are about 10 nm to 20 nm in diameter, preferably about 12 nm to 18 nm in diameter, and even more preferably about 13 nm to 17 nm in diameter. In some embodiments, the halloysite is not substantially intercalated, although some natural intercalation is expected. In some embodiments, the halloysite is intercalated to some extent, whether naturally and / or intentionally. In some embodiments, the layered halloysite is intentionally intercalated with organic or inorganic species to increase the performance of the catalyst, wherein the organic or inorganic species include, but are not limited to, precious metals (e.g., ruthenium, iridium, palladium), fatty acids (e.g., stearic acid), salts (e.g., NH4CI. HiPtCk. IrCh, Pt(acac)2, Pd(acac)2) and carbon or graphitic carbon nanotubes. In some embodiments, the halloysite acts as support for metal nanoparticles (e.g., Fe, Co, Ni, Pd, Ag, Cu, Ce, Cd, Zn, Ti, Au, La, Mo, Pt, Mn), whether adsorbed to the surface and / or located inside the tubes. In some embodiments, metal is impregnated on the outside (i.e., on or in the external siloxane surface) or inside (i.e., on or in the internal alumina! surface) of the halloysite using a metal precursor to increase the performance of the catalyst. In some embodiments, the inner diameter of the halloysite structure can be enlarged using an acid treatment to increase the performance of the catalyst. In some embodiments, the pyrolysis catalyst material is regenerated for further catalytic reactions. In some embodiments, the pyrolysis catalyst material comprises a halloysite or a substantially halloysitic material, and it is regenerated through calcination in air for reuse. It should be appreciated by the person skilled in the art that more than one pyrolysis reactor can be set up in parallel and the catalyst in one pyrolysisAttorney Docket No.: JHU -44209.601reactor can be regenerated while another pyrolysis reactor remains online, thus allowing for continuous production.

[0044] In some embodiments, the catalyst in the catalytic aromatization reactor R2, hereinafter the aromatization catalyst, include those containing internal porosity selected according to pore size (e.g., mesoporous and pore sizes typically associated with zeolites). In some embodiments, the aromatization catalyst may be selected from naturally occurring zeolites, synthetic zeolites and combinations thereof. In some embodiments, the aromatization catalyst may be a ZSM-5 zeolite catalyst, as would be understood by those skilled in the art. In some embodiments, such a aromatization catalyst can comprise acidic sites. In some embodiments, the zeolite catalysts include, but are not limited to, ferrierite, zeolite Y, zeolite beta, mordenite, MCM-22, ZSM-23, ZSM-57, SUZ-4, EU-1, ZSM-11. (S)A1PO-31, SSZ-23. ZSM-4, ZSM-5, ZSM-12, ZSM-20, ZSM-22, ZSM-34, ZSM-35, ZSM-48, and ZSM-50. In some embodiments, in addition to a zeolite, the aromatization catalyst material further comprises at least one metal species. In some embodiments, the aromatization catalyst material comprises a metal-exchanged zeolite comprising at least one transition metal is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Pt, Pd, Ir, Au, Ag, Ru, Rh, Re, Os, Mo, and W. In some embodiments, the aromatization catalyst material comprises a metal-exchanged zeolite comprising a Group VIII metal selected from platinum, palladium, silver, gold, rhodium, ruthenium, and iridium, for example as disclosed in International Patent Application No. PCT / US2021 / 033478 filed on 20 May 2021 in the name of Chao Wang, et al., and entitled “Efficient and Selective Conversion of High- Den ity Polyethylene into Valuable Hydrocarbons,” which is hereby incorporated herein in its entirety. In some embodiments, the aromatization catalyst material comprises a metal-exchanged zeolite comprising a platinum-group metal free catalyst comprising nickel and a zeolite, as disclosed in co-pending U.S. Provisional Patent Application filed on 27 March 2025 in the name of Chao WANG, Ronaldo PANGESTU HADI, and Noah ZECHER-FREEMAN, and entitled “Platinum Group Metal-Free Zeolite Catalyst for Upcycling Plastic Waste to Aromatics,” which is hereby incorporated herein in its entirety. In some embodiments, the aromatization catalyst material must be regenerated for further catalytic reactions. In some embodiments, the aromatization catalyst material comprises a zeolite which is regenerated in situ with flowing air for reuse. It should be appreciated by the person skilled in the art that more than one aromatization reactor can be set up in parallel and the catalystAttorney Docket No.: JHU -44209.601in one aromatization reactor can be regenerated while another aromatization reactor remains online, thus allowing for continuous production.

[0045] In some embodiments, the hydrogen gas of the externally-provided gas is generated in proximity to the upcycling system. For example, in some embodiments, hydrogen gas is generated electrochemically, e.g., from the electrolysis of seawater, as well understood by the person skilled in the art. In some embodiments, a portable system can be located on a coastline of, or within, a body of seawater comprising salt and can be a source of marine plastic waste and seawater for the generation of hydrogen gas using electrolysis. In some embodiments, the electrolysis process comprises the use of an electrolyzer, which converts water to hydrogen gas and oxygen gas. In some embodiments, the electrolyzer is one of a polymer electrolyte membrane (PEM) electrolyzer, an alkaline electrolyzer, or a solid oxide electrolyzer. It should be appreciated by the person skilled in the art that the hydrogen gas can be generated using other methods including, but not limited to, steam methane reforming, partial oxidation of heavier hydrocarbons, coal gasification, biogas gasification, and methane pyrolysis. In some embodiments, hydrogen gas is used in the feeding gas. In some embodiments, hydrogen gas is used in the feeding gas and is used to provide energy to other parts of the upcycling system.

[0046] It should be appreciated by the person skilled in the art that the upcycling system described herein can be portable, but it is not required.

[0047] Methods of collecting plastic waste are well known in the art. For example, in some embodiments, the plastic waste is obtained from municipal recycling programs. In some embodiments, the plastic waste is collected from harbors, water reservoirs (lakes, ponds), rivers (rivers, canals) and coastal areas. In some embodiments, manual collection is used wherein workers maneuver motorized boats and collect the waste with a dip net or other collection means. In some embodiments, mechanized collection is used, wherein vehicles specifically designed to perform clean-up operations, maneuvered by on-board human operators, are able to collect floating wastes by a grid bucket. In some embodiments, robotic collection is used, including wire-guided waste collection modules. Robotic collection can also include aquatic drones that collect floating waste in aquatic areas. Another robot collector accumulates the waste between two hulls. To collect floating plastic waste from the ocean, floating net barriers having a large U shape can be pulled behind two ships.Attorney Docket No.: JHU -44209.601

[0048] Accordingly, in a first aspect, a system for upcycling plastic waste to produce aromatic compounds is described, said system comprising:at least one pyrolysis reactor;at least one condenser;at least one catalytic aromatization reactor; andat least one gas-liquid flash separator.In some embodiments of the first aspect, the system further comprises at least one plastic granulation system upstream of, and communicatively connected to, the at least one pyrolysis reactor. In some embodiments of the first aspect, the at least one pyrolysis reactor comprises a fluidized bed. In some embodiments, the fluidized bed comprises a heating medium, a pyrolysis catalyst, or both. In some embodiments, the heating medium comprises sand. In some embodiments, the pyrolysis catalyst comprises a substantially halloysitic material. In some embodiments of the first aspect, a source of carrier gas can be introduced to the at least one pyrolysis reactor at an inlet. In some embodiments of the first aspect, the carrier gas comprises hydrogen gas, optionally an inert gas, and / or optionally a C1-C4 gas. In some embodiments of the first aspect, the carrier gas comprises 1-10% H2 in N2. In some embodiments of the first aspect, the at least one pyrolysis reactor is operated at temperature in a range of about 400°C to about 500°C to pyrolyze plastic waste into a pyrolysis product. In some embodiments of the first aspect, the at least one condenser is positioned downstream of. and communicatively connected to, the at least one pyrolysis reactor via line 1. In some embodiments of the first aspect, the at least one condenser has a temperature no greater than about 250°C, wherein the light hydrocarbons and the heavy hydrocarbons in the pyrolysis product can be separated from one another. In some embodiments of the first aspect, the at least one condenser is communicatively connected to the at least one pyrolysis reactor via line 5 for the return of the heavy hydrocarbons to the at least one pyrolysis reactor for additional pyrolysis of same. In some embodiments of the first aspect, the at least one catalytic aromatization reactor is positioned downstream of, and is communicatively connected to, the at least one condenser. In some embodiments of the first aspect, light hydrocarbons from the condenser are heated to temperature of about 550-700°C in the at least one catalytic aromatization reactor to convert at least a fraction of the light hydrocarbons to at least one aromatic compound. In some embodiments of the first aspect, the at least one gas-liquid flash separator is positioned downstream of, and is communicatively connected to, the at least oneAttorney Docket No.: JHU -44209.601catalytic aromatization reactor. Tn some embodiments of the first aspect, the temperature of the at least one gas-liquid flash separator is about -20°C to about 2°C, or about the freezing point of water, at about 1 bar, and the at least one aromatic compound is separated from at least one gas comprising C1-C4 hydrocarbons, hydrogen gas, or a combination thereof. In some embodiments of the first aspect, the at least one aromatic compound leaving the at least one gas-liquid flash separator is a liquid selected from the group consisting of benzene, toluene, indane, indene. 2-ethyl toluene, 3-ethyl toluene, 4-ethyl toluene, trimethyl benzenes, ethylbenzene, styrene, cumene, methylbenzene, propylbenzene, xylenes, naphthalene, methyl-naphthalene, anthracene, 9.10-dimethylanthracene, pyrene, phenanthrene, dimethyl-naphthalene, ethyl-naphthalene, hydrindene, methyl-hydrindene, dymethyl-hydrindene, and combinations thereof, preferably benzene, toluene, xylenes, and combinations thereof. In some embodiments of the first aspect, the at least one gasliquid flash separator is communicatively connected to the inlet of the at least one pyrolysis reactor for the return of the at least one gas comprising C1-C4 hydrocarbons, hydrogen gas, or a combination thereof, to the at least one pyrolysis reactor as a source of the carrier gas. In some embodiments of the first aspect, the system further comprises a heat integration system. In some embodiments of the first aspect, the heat integration system comprises a system that diverts heat generated in the at least one catalytic aromatization reactor to: (a) heat the light hydrocarbons entering the at least one catalytic aromatization reactor; (b) heat the carrier gas entering the at least one pyrolysis reactor in proximity to the inlet; or both.

[0049] In a second aspect, a method of upcycling plastic waste to produce at least one aromatic compound is described, said method comprising:introducing plastic waste and a carrier gas to at least one pyrolysis reactor to pyrolyze the plastic waste into a pyrolysis product;moving the pyrolysis product to at least one condenser to separate light hydrocarbons from heavy hydrocarbons;moving the light hydrocarbons to at least one catalytic aromatization reactor to convert at least a fraction of the light hydrocarbons into at least one aromatic compound; andmoving the a stream comprising the at least one aromatic compound to at least one gasliquid flash separator to separate the at least one aromatic compound from at least one gas selected from the group consisting of C1-C4 hydrocarbons, hydrogen gas. and a combination thereof.Attorney Docket No.: JHU -44209.601In some embodiments of the second aspect, the method further comprises granulating the plastic waste into pellets prior to introduction to the at least one pyrolysis reactor. In some embodiments of the second aspect, the pellets have a size in a range from about 1 mm to about 5 mm. In some embodiments of the second aspect, the carrier gas is introduced to an inlet of the at least one pyrolysis reactor. In some embodiments of the second aspect, the carrier gas comprises hydrogen gas. optionally an inert gas, and / or optionally a C1-C4 gas. In some embodiments of the second aspect, the carrier gas comprises 1-10% H2 in N2. In some embodiments of the second aspect, the at least one pyrolysis reactor is operated at temperature in a range of about 400°C to about 500°C. In some embodiments of the second aspect, the at least one condenser has a temperature no greater than about 250°C, wherein the heavy hydrocarbons in the pyrolysis product can be separated from the light hydrocarbons. In some embodiments of the second aspect, the at least one condenser is communicatively connected to the at least one pyrolysis reactor for the return of the heavy hydrocarbons to the at least one pyrolysis reactor for additional pyrolysis of same. In some embodiments of the second aspect, the at least one catalytic aromatization reactor is maintained at a temperature of about 550-700°C. In some embodiments of the second aspect, the temperature of the at least one gas-liquid flash separator is maintained at about -20°C to about 2°C, or about the freezing point of water, at about 1 bar. In some embodiments of the second aspect, the at least one aromatic compound is a liquid and is selected from the group consisting of benzene, toluene, indane, indene, 2-ethyl toluene, 3-ethyl toluene, 4-ethyl toluene, trimethyl benzenes, ethylbenzene, styrene, cumene, methylbenzene, propylbenzene, xylenes, naphthalene, methyl-naphthalene, anthracene, 9.10-dimethylanthracene, pyrene, phenanthrene, dimethyl-naphthalene, ethylnaphthalene, hydrindene, methyl-hydrindene, dymethyl-hydrindene, and combinations thereof, preferably benzene, toluene, xylenes, and combinations thereof. In some embodiments of the second aspect, the at least one gas comprising C1-C4 hydrocarbons, hydrogen gas, or a combination thereof, is returned to an inlet of the at least one pyrolysis reactor as a source of the carrier gas. In some embodiments of the second aspect, the method further comprising a heat integration system. In some embodiments of the second aspect, the heat integration system comprises a system that diverts heat generated in the at least one catalytic aromatization reactor to: (a) heat the light hydrocarbons entering the at least one catalytic aromatization reactor; (b) heat the carrier gas entering the at least one pyrolysis reactor in proximity to the inlet; or both.Attorney Docket No.: JHU -44209.601[0050| Tn a third aspect, a system for converting plastic waste into plastic pellets is described, said system comprising:at least one first shredder to shred plastic into plastic flakes;at least one washing system to wash and rinse the plastic flakes;at least one drying system to dry wet plastic flakes;at least one melting system to melt plastic flakes into a plastic aggregate material; at least one second shredder to shred the plastic aggregate material into plastic pellets; andoptionally at least one screening device to obtain plastic pellets of a desired size.

[0051] In a fourth aspect, a method of converting plastic waste into plastic pellets is described, said method comprising:introducing plastic waste into a first shredder to obtain plastic flakes;washing and rinsing the plastic flakes at least once;separating the washed / rinsed plastic flakes from wastewater;optionally treating the wastewater for reuse in the method;drying the washed / rinsed plastic flakes;melting the dried plastic flakes in a vacuum or inert atmosphere to produce a plastic aggregate material;shredding the plastic aggregate material in a second shredder to produce plastic pellets; andoptionally screening the plastic pellets to obtain a desired size of same.Computer program product

[0052] The present subject matter described in the first through fourth aspects may be a system, a method, and / or a computer program product. In some embodiments, the computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to cany out aspects of the present subject matter.

[0053] In some embodiments, the computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be. for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductorAttorney Docket No.: JHU -44209.601storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a RAM, a ROM, an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

[0054] In some embodiments, computer readable program instructions described herein can be downloaded to respective computing / processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and / or a wireless network, or Near Field Communication. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and / or edge servers. A network adapter card or network interface in each computing / processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing / processing device.

[0055] In some embodiments, computer readable program instructions for carrying out operations of the present subject matter may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++, Javascript or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The computer readable program instructions may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may beAttorney Docket No.: JHU -44209.601connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present subject matter.

[0056] In some embodiments, the computer readable program instructions may be provided to a processor of a computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions / acts specified in the flowchart and / or block diagram block or blocks. In some embodiments, the computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function / act specified in the flowchart and / or block diagram block or blocks.

[0057] In some embodiments, the computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions / acts specified in the flowchart and / or block diagram block or blocks.

[0058] In light of the present disclosure and the general level of skill in the art, those of skill can appreciate that the following examples are intended to be exemplary only and that numerous changes, modifications, and alterations can be employed without departing from the scope of the presently disclosed subject matter. The synthetic descriptions and specific examples that follow are only intended for the purposes of illustration, and are not to be construed as limiting in any manner to make compounds of the disclosure by other methods.Attorney Docket No.: JHU -44209.601EXAMPLE 1

[0059] Referring to FIG. 1, plastic waste upcycling was conducted in an upcycling system described herein. In Example 1, the at least one pyrolysis reactor comprised the heating medium only. The material balance of each relevant stream, in mass percentage based on the total mass of the material, is shown in Table 1 below for 100 kg / day plastic feed.Table 1: Material balance throughout the upcycling system of FIG. 1.Stream 1 3 6 7 9 8 10 11 Mass Flows4 166 92gl 13417 1 1 3694 9.73g0 4879251 (kg / hr)Mass Percentage (%)Plastic 100.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 H2 0.0000 10.6458 0.0000 7.7184 0.0006 10.6458 10.6458 10.6458 Cl 2+ 0.0000 0.0000 45.8605 0.0000 0.0000 0.0000 0.0000 0.0000 Methane 0.0000 38.8370 0.0000 28.1637 0.0239 38.8370 38.8370 38.8370 Ethylene 0.0000 12.9820 0.0000 9.4265 0.0527 12.9820 12.9820 12.9820 Ethane 0.0000 15.4356 0.1976 11.2199 0.1054 15.4356 15.4356 15.4356 Propylene 0.0000 11.6998 6.0265 8.5795 0.3530 11.6998 11.6998 11.6998 Propane 0.0000 0.0000 0.3952 0.0000 0.0000 0.0000 0.0000 0.0000 n-butane 0.0000 0.6407 0.0000 0.4940 0.1074 0.6407 0.6407 0.6407 Isobutylene 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 1-butene 0.0000 1.5475 2.9638 1.1821 0.2187 1.5475 1.5475 1.5475 cis-2-butene 0.0000 0.2660 18.2770 0.2100 0.0625 0.2660 0.2660 0.2660 trans-2-butene 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 1 -pentene 0.0000 0.0000 11.4602 0.0000 0.0000 0.0000 0.0000 0.0000 n-pentane 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 1 -hexene 0.0000 0.0000 7.4096 0.0000 0.0000 0.0000 0.0000 0.0000 1 -heptene 0.0000 0.0000 7.4096 0.0000 0.0000 0.0000 0.0000 0.0000 Benzene 0.0000 6.7667 0.0000 18.8711 50.7835 6.7667 6.7667 6.7667 Toluene 0.0000 1.1198 0.0000 11.4146 38.5564 1.1198 1.1198 1.1198 p-Xylene 0.0000 0.0165 0.0000 0.6810 2.4330 0.0165 0.0165 0.0165 o-Xylene 0.0000 0.0135 0.0000 0.7630 2.7392 0.0135 0.0135 0.0135 m-Xylene 0.0000 0.0291 0.0000 1.2761 4.5637 0.0291 0.0291 0.0291 EXAMPLE 2

[0060] Referring again to FIG. 1, plastic waste upcycling was conducted in an upcycling system described herein. In Example 2, the at least one pyrolysis reactor comprised the R1 catalyst halloysite and the heating medium, e.g., sand. As illustrated in FIG. 4, the resulting crackedAttorney Docket No.: JHU -44209.601hydrocarbon comprises C3-C8 hydrocarbons instead of C12+. Advantageously, by adjusting the materials in the at least one pyrolysis reactor, the output can be tuned to obtain more of a specifically preferred hydrocarbon.

Claims

Attorney Docket No.: JHU -44209.601CLAIMSWhat is claimed is:

1. A system for upcycling plastic waste to produce at least one aromatic compound, said system comprising:at least one pyrolysis reactor;at least one condenser;at least one catalytic aromatization reactor; andat least one gas-liquid flash separator.

2. The system of claim 1, further comprising at least one plastic granulation system upstream of, and communicatively connected to, the at least one pyrolysis reactor.

3. The system of claims 1 or 2, wherein the at least one pyrolysis reactor comprises a fluidized bed.

4. The system of claim 3, wherein the fluidized bed comprises a heating medium, a pyrolysis catalyst, or both.

5. The system of claim 4, wherein the heating medium comprises sand.

6. The system of claim 4, wherein the pyrolysis catalyst comprises a substantially halloysitic material.

7. The system of any of claims 1-6, wherein a source of carrier gas can be introduced to the at least one pyrolysis reactor at an inlet.

8. The system of claim 7, wherein the carrier gas comprises hydrogen gas, optionally an inert gas, and / or optionally a C1-C4 gas.Attorney Docket No.: JHU -44209.6019. The system of claims 7 or 8, wherein the carrier gas comprises 1-10% H2 in N2.

10. The system of any of claims 1-9, wherein the at least one pyrolysis reactor is operated at temperature in a range of about 400°C to about 500°C to pyrolyze plastic waste into a pyrolysis product.

11. The system of any of claims 1-10, wherein the at least one condenser is positioned downstream of, and communicatively connected to. the at least one pyrolysis reactor via a first line.

12. The system of claim 11, wherein the at least one condenser has a temperature no greater than about 250°C, wherein the light hydrocarbons can be separated from the heavy hydrocarbons in the pyrolysis product .

13. The system of claim 12, wherein the at least one condenser is communicatively connected to the at least one pyrolysis reactor via a second line for the return of the heavy hydrocarbons to the at least one pyrolysis reactor for additional pyrolysis of same.

14. The system of any of claims 1-13, wherein the at least one catalytic aromatization reactor is positioned downstream of, and is communicatively connected to, the at least one condenser.

15. The system of claim 14, wherein the light hydrocarbons are heated to temperature of about 550-700°C in the at least one catalytic aromatization reactor to convert at least a fraction of the light hydrocarbons to at least one aromatic compound.

16. The system of any of claims 1-15, wherein the at least one gas-liquid flash separator is positioned downstream of, and is communicatively connected to, the at least one catalytic aromatization reactor.

17. The system of claim 16, wherein the temperature of the at least one gas-liquid flash separator is about -20 °C to about 2 °C at about 1 bar, and wherein a stream comprising at least one aromaticAttorney Docket No.: JHU -44209.601compound is separated from at least one gas selected from the group consisting of C1-C4 hydrocarbons, hydrogen gas, and a combination thereof.

18. The system of any of claims 1-17, wherein the at least one aromatic compound is a liquid and is selected from the group consisting of benzene, toluene, indane, indene, 2-ethyl toluene, 3-ethyl toluene, 4-ethyl toluene, trimethyl benzenes, ethylbenzene, styrene, cumene, methylbenzene, propylbenzene, xylenes, naphthalene, methyl-naphthalene, anthracene, 9.10-dimethylanthracene, pyrene, phenanthrene, dimethyl-naphthalene, ethyl-naphthalene, hydrindene, methyl-hydrindene, dymethyl-hydrindene, and combinations thereof.

19. The system of any of claims 1-18, wherein the at least one aromatic compound is a liquid and is selected from benzene, toluene, xylenes, and combinations thereof.

20. The system of claim 17. wherein the at least one gas-liquid flash separator is communicatively connected to the inlet of the at least one pyrolysis reactor for the return of the at least one gas comprising C1-C4 hydrocarbons, hydrogen gas, or a combination thereof, to the at least one pyrolysis reactor as a source of the earner gas.

21. The system of any of claims 1-20, further comprising a heat integration system.

22. The system of claim 21, wherein the heat integration system comprises a system that diverts heat generated in the at least one catalytic aromatization reactor to: (a) heat the light hydrocarbons entering the at least one catalytic aromatization reactor; (b) heat the carrier gas entering the at least one pyrolysis reactor in proximity to the inlet; or both.

23. A method of upcycling plastic waste to produce at least one aromatic compound, said method comprising:introducing plastic waste and a carrier gas to at least one pyrolysis reactor to pyrolyze the plastic waste into a pyrolysis product;moving the pyrolysis product to at least one condenser to separate light hydrocarbons from heavy hydrocarbons;Attorney Docket No.: JHU -44209.601moving the light hydrocarbons to at least one catalytic aromatization reactor to convert at least a fraction of the light hydrocarbons into at least one aromatic compound; andmoving a stream comprising the at least one aromatic compound to at least one gas-liquid flash separator to separate the at least one aromatic compound from at least one gas selected from the group consisting of C1-C4 hydrocarbons, hydrogen gas, and a combination thereof.

24. The method of claim 23, further comprising granulating the plastic waste into pellets prior to introduction to the at least one pyrolysis reactor.

25. The method of claim 24, wherein the pellets have a size in a range from about 1 mm to about 5 mm.

26. The method of any of claims 23-25, wherein the at least one pyrolysis reactor comprises a fluidized bed.

27. The method of claim 26, wherein the fluidized bed comprises a heating medium, a pyrolysis catalyst, or both.

28. The method of claim 27, wherein the heating medium comprises sand.

29. The method of claim 27, wherein the pyrolysis catalyst comprises a substantially halloysitic material.

30. The method of any of claims 23-29, wherein the carrier gas is introduced to an inlet of the at least one pyrolysis reactor.

31. The method of any of claims 23-30, wherein the carrier gas comprises hydrogen gas, optionally an inert gas, and / or optionally a C1-C4 gas.

32. The method of any of claims 23-31, wherein the carrier gas comprises 1-10% H2 in N2.Attorney Docket No.: JHU -44209.60133. The method of any of claims 23-32, wherein the at least one pyrolysis reactor is operated at temperature in a range of about 400°C to about 500°C.

34. The method of any of claims 23-33, wherein the at least one condenser has a temperature no greater than about 250°C, wherein the heavy hydrocarbons can be separated from the light hydrocarbons in the pyrolysis product.

35. The method of any of claims 23-34, wherein the at least one condenser is communicatively connected to the at least one pyrolysis reactor for the return of the heavy hydrocarbons to the at least one pyrolysis reactor for additional pyrolysis of same.

36. The method of any of claims 23-35, wherein the at least one catalytic aromatization reactor is maintained at a temperature of about 550-700°C.

37. The method of any of claims 23-36, wherein the temperature of the at least one gas-liquid flash separator is maintained at about -20°C to about 2°C at about 1 bar.

38. The method of any of claims 23-37, wherein the at least one aromatic compound is a liquid and is selected from the group consisting of benzene, toluene, indane, indene, 2-ethyl toluene, 3-ethyl toluene, 4-ethyl toluene, trimethyl benzenes, ethylbenzene, styrene, cumene, methylbenzene, propylbenzene, xylenes, naphthalene, methyl-naphthalene, anthracene, 9.10-dimethylanthracene, pyrene, phenanthrene, dimethyl-naphthalene, ethyl-naphthalene, hydrindene. methyl-hydrindene, dymethyl-hydrindene, and combinations thereof.

39. The method of any of claims 23-38, wherein the at least one aromatic compound is a liquid and is selected from benzene, toluene, xylenes, and combinations thereof.

40. The method of any of claims 23-39, wherein the at least one gas comprising C1-C4 hydrocarbons, hydrogen gas, or a combination thereof, is returned to an inlet of the at least one pyrolysis reactor as a source of the earner gas.Attorney Docket No.: JHU -44209.60141. The method of any of claims 3-40, further comprising a heat integration system.

42. The method of claim 41, wherein the heat integration system comprises a system that diverts heat generated in the at least one catalytic aromatization reactor to: (a) heat the light hydrocarbons entering the at least one catalytic aromatization reactor; (b) heat the carrier gas entering the at least one pyrolysis reactor in proximity to the inlet; or both.

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