A process for chemically recycling waste plastics

Abstract

A distributed system for converting waste plastics, polymers, and other waste materials into useful chemical and fuel products (e.g., paraffins, olefins, and aromatics (e.g., BTX)) in a thermochemical process is described, where pretreatment involves raising the temperature of the waste plastics to at least 100°C. A two-step process for converting waste plastics, polymers, and other waste materials into useful chemical and fuel products (e.g., paraffins, olefins, and aromatics (e.g., BTX)) is described, which involves a first step of pyrolysis and a second step of catalytic fluidized bed upgrading of the resulting raw pyrolysis products without separation. In another embodiment, a method or system for upgrading waste plastics into useful products includes a first pyrolysis reactor and a catalytic fluidized bed reactor that together form one spoke of a "hub-and-spoke" network for producing generated chemical intermediates, where each of multiple plastic upgrading sites (spokes) produces a condensed phase product that is sent to a central processing facility (hub) for separation and purification into product streams, or for catalytic upgrading, separation, and purification into product streams.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of priority to U.S. Patent Application No. 17 / 990,642 (filed November 18, 2022) and U.S. Provisional Patent Application No. 63 / 579,945 (filed August 31, 2023).

[0002] The present invention relates to the conversion of waste plastics, polymers, and other waste materials into useful chemical and fuel products, such as paraffins, olefins, aromatics (e.g., BTX (a mixture of benzene, toluene, and xylene)), in a thermochemical process, preferably a two-step process involving a first step of pyrolysis and a second step of upgrading the resulting product mixture. [Background technology]

[0003] In 2019, the United States generated 55.2 million tons of plastic, accounting for 13% of its MSW production. Globally, over 368 million tons of plastic was produced. By some estimates, 8.3 billion tons of plastic have been produced, 6.3 billion tons becoming waste, with only 9% of this being recycled. Plastic recycling involves recovering scrap or waste plastic and reprocessing the material into useful products. However, since China banned the import of waste plastic in 2018, the recycling rate in the United States is estimated to have fallen to just 4.4%.

[0004] Recycling plastics is difficult due to the chemical properties of long-chain organic polymers and low economic returns. Furthermore, waste plastic materials often need to be sorted into various plastic resin types (e.g., low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET)) and recycled separately. Pyrolysis and catalytic pyrolysis processes are known in which waste plastics are heated to produce products such as liquid oil, gas, and carbon black.

[0005] Plas-TCat™ is a catalytic fluidized bed process that uses a zeolite catalyst to convert polymer / plastic materials, particularly waste plastics that may be destined for landfills or incinerators, into a mixture of products: permanent gases, C2-C4 light olefins, C1-C4 light paraffins, C5+ hydrocarbons (benzene, toluene, and xylenes (“BTX”)), aromatic and non-aromatic naphtha molecules, C11+ hydrocarbons, coke and charcoal, and small amounts of by-products. Plastic mixtures with relatively high hydrogen:carbon molar ratios (e.g., polyethylene (PE), polypropylene, polystyrene, and combinations thereof) can be converted to olefins and aromatics.

[0006] U.S. Patent Application No. 2016 / 0289569 by Baird et al. describes a process for pyrolyzing biomass into pyrolysis oil, separating and upgrading the pyrolysis oil, deoxygenating the upgraded pyrolysis oil to obtain aromatic and paraffinic products, and further upgrading the paraffinic products by aromatization.

[0007] U.S. Patent No. 10,233,395 to Ward relates to a process for converting mixed waste plastics (MWP) into petrochemicals (the MWP stream is fed to a pyrolysis reactor), converting the MWP into separate gaseous and liquid streams, and further treating the gaseous and liquid streams separately.

[0008] Fukuda et al., in U.S. Pat. No. 4,851,601, describe a process for pyrolyzing plastics in a tank reactor with added solids to minimize material buildup on the reactor walls and reacting steam in a fixed-bed catalytic reactor.

[0009] Bartek et al., in U.S. Pat. No. 9,040,761, describe a process for pyrolyzing biomass and plastics in a fluidized bed of heat transfer material and reacting the products with a catalyst in a second reactor to produce bio-oil.

[0010] Saito et al., in US Pat. No. 4,584,421, describe a process for thermally melting and pyrolyzing plastic scrap and passing the vaporous products over a bed of catalyst particles.

[0011] In their papers "Catalyst Performance in the HDPE Pyrolysis-Reforming Under Reaction-Regeneration Cycle" (Catalysts 2019, 9, 414) and "Waste Plastics Valorization by Fast Pyrolysis and In Line Catalytic Steam Reforming for Hydrogen Production" (M. Olazar Materials Science, DOI: 10.5772 / INTECHOPEN.85048 (July 9, 2019)), Barbarias et al. describe the conversion of waste plastics to synthesis gas by pyrolysis in a conical spouted-bed reactor and steam reforming of the formed volatiles (gases and waxes) in a fluidized bed of Ni-containing catalyst.

[0012] Schenk et al., in U.S. Patent Application No. US20220195310A1, describe a process for preparing BTX by pyrolyzing a plastic mixture at 600-1000°C and catalytically upgrading the vapor to an aromatics-containing mixture in a fluidized bed at 450-700°C.

[0013] Diebold et al., in U.S. Pat. No. 7,909,899, disclose a process for converting biomass to gaseous fuel using downdraft vaporization in an automated process (which may be part of a distributed system with automated central control).

[0014] Foody et al., in U.S. Pat. No. 11,289,696, describe a method for producing partially purified biogas at a first processing site and transporting it by vehicle to a second processing site where the methane, along with methane from other processing sites, is processed into fuel or fuel intermediates.

[0015] Doucet and Chaouki, in U.S. Patent No. 2016 / 0200982, disclose a system for conducting small-scale pyrolysis in a distributed manner, collecting by-products, and transporting the by-products to a by-product processor for further use.

[0016] Waste plastics are collected at numerous local facilities, each handling a small amount of plastic per day, either as part of municipal solid waste or as a separate recycling stream. In either case, most of the material becomes part of the 25 million tons of plastic sent annually to one of the more than 2,600 landfills in the United States. The amount of waste plastics available at any one site is typically only a few tens of metric tons per day.

[0017] Chemical plastic recycling plants include feed handling, cleaning, processing (e.g., thermal cracking and catalytic pyrolysis), recovery, separation, and purification operations. Separation and purification facility costs often represent 35-50% of the overall facility capital cost. If the size of individual resources is small, the upgrading process is economically unfavorable because it cannot take advantage of the economies of scale available to larger resources.

[0018] Smaller capacity plants cost more per ton of product than larger plants due to a lack of economies of scale. One way to take advantage of economies of scale in separation and purification functions is to network together multiple plants that produce a crude mixture of liquid products of similar composition and send the crude mixture to a refinery or other central processing facility for separation and purification into chemical-grade materials.

[0019] Another challenge is that the composition of waste materials varies greatly from site to site, due to local conditions and the source of such materials. For example, some sites are located near sources of construction waste containing large amounts of chlorine-containing plastics (e.g., PVC), while other sites receive waste containing little or no chlorine-containing waste. Simple combined processing of these wastes requires processes that can accommodate chlorine-containing materials, while processing of chlorine-free materials can be achieved with less complex and less expensive equipment. In summary, different pretreatment schemes are required to make different waste plastic mixtures acceptable as feed for the pyrolysis upgrading process.

[0020] Another challenge is the transportation and storage of post-consumer plastics recovered from waste treatment facilities, which are often contaminated with food, agricultural waste, feces, or other hazardous waste. Contaminated plastics can harbor diseases, parasites, and pathogens and can cause noxious odors and irritating vapors. The transportation and storage of these contaminated materials poses health hazards to workers who handle them and to people in nearby areas. One object of the present invention is to disclose a pretreatment process for sanitizing, decontaminating, and / or sterilizing plastics prior to transportation and storage in order to upgrade them into valuable products.

[0021] A need exists for a system for upgrading waste plastic materials whereby waste plastics can be pretreated at individual sites, each configured to accommodate a specific waste composition, and the pretreated material from each of the multiple sites is either catalytically upgraded at the same site as pretreatment or collected at a central site for catalytic upgrading to produce aromatics, olefins, paraffins, or similar valuable products. Summary of the Invention

[0022] A method for producing olefins and aromatic hydrocarbons from waste plastics, comprising feeding the plastic mixture to a two-stage process including a first stage in which the plastic mixture is anaerobically pyrolyzed, and a second stage in which the raw products of the first stage, without separation, are catalytically reacted to produce olefins and aromatics.

[0023] In one aspect, the present invention provides a method or system for upgrading waste plastics into useful products, comprising a first pyrolysis reactor and a catalytic fluidized-bed reactor, which together form one spoke of a "hub-and-spoke" network for producing purified chemical intermediates. Each of the multiple plastic upgrading sites (spokes) produces a condensed-phase product that is sent to a central processing facility (hub) for separation and purification into product streams, or for catalytic upgrading into product streams, separation, and purification. The chemical intermediates can be selected from the group consisting of benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6-C20 paraffins, and olefins, ethylene, propylene, naphthalene, and combinations thereof. The chemical intermediates can be separated and purified at the central separation and purification facility. In a preferred method or system, at least 2, or at least 3, or at least 5, or at least 7, or at least 10, or at least 15, or 2 to 20, or 3 to 10, or 5 to 10 plastic pyrolysis facilities feed a central catalytic upgrading, separation, and refining facility. The method or system is suitable for large-scale operation, for example, the total crude product mixture prepared in the plastic pyrolysis facilities fed into the central catalytic upgrading, separation, and refining facility is at least 20, at least 50, at least 100, at least 150, or at least 200 metric tons per day, or 20 to 500, 30 to 200, or 50 to 150 metric tons per day of crude product mixture. The central catalytic upgrading, separation, and refining facility can be located at a refinery.

[0024] In another aspect, the present invention provides a system and / or method for upgrading waste plastics into useful products, comprising a plurality of plastic pre-treatment facilities, wherein: a. each pre-treatment facility forms one spoke of a "hub and spoke" network; b. pre-treatment at each pre-treatment facility comprises increasing the temperature of the waste plastic to at least 100°C; c. the hub comprises a catalytic pyrolysis unit or each spoke comprises a catalytic pyrolysis unit; and d. at least a portion of the products of each spoke are collected and processed in a central processing facility (hub) for upgrading, separation, and purification into product streams.

[0025] In another aspect, the present invention provides a method for converting plastics to olefins, aromatics, or a mixture of olefins and aromatics, the method comprising: pretreating a mixture of plastics in a pretreatment facility (one of multiple pretreatment facilities); elevating the temperature of the mixture of plastics to at least 100°C during the pretreatment process; transporting at least a portion of the products from the pretreatment facility to a fluidized bed catalytic reactor where the mixture is converted to a product mixture in the presence of a catalyst, the fluidized bed catalytic reactor being on-site with the pretreatment facility or at a different central site; recovering at least a portion of the products from one or more catalytic pyrolysis reactors; and recovering olefins or aromatics, or some combination thereof, from the catalytic pyrolysis products in a central product upgrading, separation, and refining facility.

[0026] In a further aspect, the present invention provides a method for producing chemicals or fuels, the method comprising: a. providing waste plastics at a first processing site, the first processing site being configured to receive waste plastics; b. pre-treating the waste plastics at the first processing site at a temperature of at least 100°C and transferring the pre-treated waste plastics to one or more mobile carriers; c. transporting the one or more mobile carriers to a second processing site, the second processing site being configured to receive pre-treated waste plastics from at least one additional plastic source; d. removing the pre-treated waste plastics from the one or more mobile carriers transported in step (c); and e. producing chemicals, fuels, or both using plastics from at least the pre-treated waste plastics removed in step (d) and plastics from at least one other plastic source.

[0027] The methods and / or systems of the present invention may be further characterized by one or any combination of the following features: the pretreatment process or system may include one or more of the following: collecting, separating, sorting, blending, removing contaminants, heat treating, sanitizing, decontaminating, sterilizing, dechlorinating, washing, drying, sizing, melting, filtering, pelletizing, or some combination thereof; at least one pretreatment process increases the temperature of the plastic mixture to at least 100°C, 120°C, 150°C, 180°C, 200°C, or 220°C; the pretreatment process steps can be performed in any order; the products of catalytic pyrolysis include one or more of benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6-C20 paraffins and olefins, ethylene, propylene, or naphthalene, hydrogen, or some combination thereof. The thermal treatment reactor comprises one or more reactors; the thermal treatment reactor or pyrolysis reactor is one or more of a moving bed, single screw extruder, twin screw extruder, multi-screw extruder, planetary extruder, ultrasonically assisted extruder, auger reactor, rotary kiln reactor, stirred tank reactor, or stepped grate reactor, or any combination thereof; the pre-treatment facility further comprises a shredder, a granulator, a de-packaging unit, a dewatering unit, or any combination thereof; the waste plastic collection bin or container comprises an RFID tag or barcode for efficiently tracking and managing the waste plastic; the transport vehicle for collecting the waste plastic is selected from a truck, a trailer, a rail car, a shipping container, or any suitable means of transport; the waste plastic is transported to a residential, commercial, or residential facility. The pretreated waste plastic is collected from commercial, industrial, or municipal waste, or some combination thereof; a central processing facility (hub) is located within 1 mile (1.6 km) of the waste plastic collection facility; the system further comprises a central database or control center that receives and processes real-time data from each pretreatment facility, catalytic pyrolysis reactor, and other related components; the central database or control center controls and optimizes the operation of the distributed system; transportation of the pretreated waste plastic from each pretreatment facility to the central processing facility or catalytic pyrolysis reactor is facilitated through an intelligent logistics system; the intelligent logistics system autonomously schedules and dispatches transport vehicles or devices based on the real-time capacity and demand of each facility. Either the central processing facility (hub) or the pre-processing facility is a portable modular system; the material is heated to a temperature of 180°C to 300°C in a thermal processing reactor, and the condensed product is passed to a second thermal processing reactor; a sweep gas (e.g., H2O, N2, Air, Ar, CO2, or other inert gas, or some combination of these) is supplied to the thermal processing reactor, and vapors are vented; A vapor stream comprising at least one of HCl, HBr, HI, NH, CO, or CH is exhausted from the thermal treatment reactor; the thermal treatment reactor has an inlet port and an outlet port, and the temperature at or near the inlet port can be 20-225°C (e.g., 20-100°C or 20-50°C), and the temperature at the hot outlet port can range from 300-700°C, e.g., 325-650°C, 350-600°C, or 350-575°C; the residence time of the condensed phase in the thermal treatment reactor, or in any reactor if there are multiple thermal treatment reactors, can be at least 0.5 minutes, or at least 5, 10, 20, or at least 30 minutes, or 1-60, 5-30, or 60-700°C. , 10 to 30, or 0.5 to 10 minutes; the heat treatment reactor comprises one or more single-screw, twin-screw, multi-screw, planetary-screw, or ultrasonically assisted extruders and stirred-tank reactors; the filtration is accomplished by first heating the plastic mixture in the heat treatment reactor to at least 200°C to reach a molten state and filtering to remove solids; the mixing is accomplished by passing the molten feed mixture through one or more static mixing devices maintained at a temperature of at least 100, 150, 200, 225, or 250°C, or 100 to 350, 150 to 350, 150 to 300, or 200 to 250°C. The contaminants are removed by anaerobically heating the feed mixture to a temperature of 150°C to 350°C or 250°C to 300°C in a thermal treatment reactor to at least partially decompose the polymer; the feed is heated to a temperature of 250°C to 300°C in the thermal treatment reactor and the product is passed to a second thermal treatment reactor; at least one of the thermal treatment reactors comprises a stirred tank reactor; a solid co-reactant is fed to the thermal treatment reactor; The solid co-reactant material comprises one or more materials selected from agricultural lime, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, limestone, hydrotalcite, activated carbon, or zeolite, or other solid basic materials, or any combination thereof; the solid co-reactant material recovered from the thermal treatment reactor is transferred to a combustion regenerator where the carbonaceous material reacts with air and at least a portion of the hot solid co-reactant material is returned to the thermal treatment reactor; the products produced in the pyrolysis reactor are transferred to a catalytic pyrolysis reactor containing a catalyst, without separation of the majority of the products. the molten product of the pretreatment is fed to a pelletizing process and cut into pellets; the feed to the catalytic pyrolysis reactor comprises pellets; feeding a feed mixture containing plastics to a pretreatment facility; the non-vapor products of the catalytic pyrolysis reactor, or a portion of the gas remaining after removal of the desired products, or both, are combusted to provide energy for the thermal cracking or catalytic pyrolysis process; a gas phase co-reactant or recycle stream comprising H, CO, or olefins, or some combination of these, is fed directly to the thermal treatment reactor or catalytic pyrolysis reactor; A portion of the vapor product from the catalytic pyrolysis process is fed to a condenser where it is cooled to produce a condensed material; a portion of the condensed material separated from the product stream from the thermal treatment or catalytic pyrolysis reactor is separated into fractions, and at least a portion is recycled to the thermal treatment reactor; the condensed material is separated into fractions by distillation, and at least a portion of the paraffins, olefins, or aromatics containing more than 7 carbon atoms, or combinations thereof, are recycled to the thermal treatment or catalytic pyrolysis reactor; the condensed material separated from the product stream from the thermal treatment or catalytic pyrolysis reactor is separated into fractions by distillation, and at least a portion of the fractions boiling above 300°C or boiling in the range of 300-800°C are recycled to the thermal treatment or catalytic pyrolysis reactor.

[0028] In a further aspect of the invention, a mixture containing a polymer is converted in an anaerobic process in a reactor to produce a pyrolysis stream which is fed to a fluidized bed catalytic pyrolysis process to produce olefins and aromatics.

[0029] In another aspect, the present invention provides a method for converting plastics to olefins, aromatics, or a mixture of olefins and aromatics, the method comprising: feeding a polymer or a mixture of polymers to a first pyrolysis reactor; anaerobically pyrolyzing the stream in the first reactor under conditions sufficient to produce a raw mixture comprising one or more olefins and paraffins; transferring the raw mixture from the first pyrolysis reactor without separation to a fluidized bed catalytic reactor where the mixture is converted to a product vapor mixture in the presence of a catalyst; and recovering the olefins or aromatics, or any combination thereof, from the product vapor mixture.

[0030] In a further aspect, the present invention provides a method for producing olefins and aromatics, comprising: feeding a plastic-containing stream to a first pyrolysis reactor; anaerobically pyrolyzing the stream in the first pyrolysis reactor at a temperature of 250-300°C and holding at that temperature range while vapors are removed (the hold is preferably at least 2 minutes, or at least 5 minutes, or at least 10 minutes, preferably not more than 1 hour, or not more than 30 minutes); further pyrolyzing at a higher temperature in the first pyrolysis reactor to prepare a first product mixture; passing the first product mixture produced in the first pyrolysis reactor, without separating a portion of the first product mixture, to a second pyrolysis reactor comprising a fluidized bed reactor equipped with a catalyst; catalytically reacting the first product mixture in the fluidized bed reactor to form a catalytic pyrolysis product mixture; and recovering olefins or aromatics, or some combination thereof, from the pyrolysis product mixture. The present invention may be further characterized by any one or combination of the following: a first product mixture produced in a first pyrolysis reactor is passed to a second pyrolysis reactor at a temperature above 350°C without cooling; the first pyrolysis reactor comprises a feed inlet port and an outlet port, and the temperature within the pyrolysis reactor ranges from a low temperature near the feed inlet port to a high temperature at the outlet port; the first pyrolysis reactor comprises two or more reactors in a series configuration; the catalyst in the fluidized bed reactor comprises a zeolite; the catalyst has a silica-to-aluminum ratio greater than 12 or between 12 and 240, and a CI (constraint index) of between 1 and 12 or between 5 and 10. the catalyst comprises ZSM-5; the product vapor mixture from the fluidized bed catalytic reactor comprises at least 20 wt% BTX; a solid co-reactant is supplied to the first pyrolysis reactor, and the solid co-reactant supplied to the first pyrolysis reactor comprises agricultural lime, or calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, limestone, hydrotalcite, activated carbon, or zeolite, or any combination thereof; the temperature of the fluidized bed reactor is within the range of 300°C to 800°C, 350°C to 750°C, 400°C to 700°C, 450°C to 650°C, 500°C to 600°C, or 525°C to 575°C;Benzene, toluene, or xylene is separated or recovered from the catalytic pyrolysis product mixture; at least a portion of the aromatic compounds in the catalytic pyrolysis product mixture are hydrogenated to produce naphthenes; the catalytic pyrolysis product mixture is subjected to a separation process to produce a gas stream enriched in CH4, CO, and H2, and at least a portion of the CH4, CO, and H2 gas streams are passed to a regenerator where they are combusted; the feedstock comprises a mixture of waste plastics selected from polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC) or polyvinylidene (PVCD), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or mixed resins, or any combination thereof; the catalytic pyrolysis product mixture is subjected to a separation process to produce a gas stream enriched in CH4, CO, and H2, and at least a portion of the CH4, CO, and H2 gas streams are passed to a regenerator where they are combusted; At least a portion of the vapor product from the pyrolysis process product mixture is fed to a condenser where it is cooled to produce a condensed material, and at least a portion of the condensed material is recycled to the first pyrolysis reactor; a portion of the condensed material is separated into fractions, and at least a portion of the condensed material is recycled to the first pyrolysis reactor or the second pyrolysis reactor; the condensed material is separated into fractions by distillation, and at least a portion of the paraffins, olefins, or aromatics containing more than 7 carbon atoms, or combinations thereof, are recycled to the thermal treatment or catalytic pyrolysis reactor; the higher temperature further pyrolysis step is in the range of 350-600 degrees; the temperature in the second pyrolysis reactor is maintained at a temperature at least 5°C higher than the temperature of the outlet port;

[0031] The present invention, in any of its aspects, may further be characterized by one or any combination of the following features: feeding a feed mixture containing plastics to a pyrolysis reactor, wherein the feed mixture is selected from the group consisting of polyethylene, polypropylene, polyester, polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene (ABS) copolymer, polyamide, polyurethane, polyether, polycarbonate, poly(oxide), poly(sulfide), polyarylate, polyether ketone, polyetherimide, polysulfone, polyurethane, polyvinyl alcohol, and polymers produced by polymerization of monomers such as dienes, olefins, styrene, acrylates, acrylonitrile, methacrylates, methacrylonitrile, diacids and diols, lactones, diacids and diamines, lactams, vinyl halides, vinyl esters, block copolymers thereof, and alloys thereof; providing a plastic selected from curable polymers, such as epoxy resins; phenolic resins; melamine resins; alkyd resins; vinyl ester resins; unsaturated polyester resins; crosslinked polyurethanes; polyisocyanurates; crosslinked elastomers (including, but not limited to, polyisoprene, polybutadiene, styrene-butadiene, styrene-isoprene, ethylene-propylene-diene monomer polymers); and mixtures thereof, wherein the feedstock comprises a mixture of waste plastics selected from polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC) or polyvinylidene chloride (PVCD), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or mixed resins, or any combination thereof; wherein a plastic feed stream is first heated to at least 200°C in a thermal treatment reactor to reach a molten state, filtered to remove solids, and the feed mixture is anaerobically heated to a temperature of 250-300°C in a pyrolysis reactor to at least partially decompose the polymer; The thermal treatment or pyrolysis reactor is one or more moving beds, single screw extruders, twin screw extruders, auger reactors, rotary kiln reactors, or stepped grate reactors, or combinations thereof, and the first pyrolysis reactor has an inlet port and an outlet port, and the temperature at or near the inlet port can be 20 to 225°C (e.g., 20 to 100°C or 20 to 50°C), and the temperature at the hot outlet port can range from 300 to 700°C (e.g., 325 to 650°C, 350 to 600°C, or 350 to 575°C); A two-step process including a temperature of 250-300°C and holding that temperature range while steam is removed (preferably for at least 2 minutes, or at least 5 minutes, or at least 10 minutes, preferably for 1 hour or less, or 30 minutes or less); the residence time of the condensed phase in the first pyrolysis reactor, or in any reactor if there are multiple pyrolysis reactors (prior to the catalytic fluidized bed reactor), is at least 1 minute, or at least 5 minutes, or at least 10 minutes, or at least 20 minutes, or at least 30 minutes, or from 1 to 60 minutes, or from 5 to 30 minutes, or from 10 to 30 minutes; The pyrolysis reactor comprises two or more reactors in a series configuration; The feed is heated to a temperature of 250-300°C in the first pyrolysis reactor, and the product is passed to the second pyrolysis reactor; A sweep gas (e.g., H2O, N2, Ar, CO2, or any combination thereof) is supplied to the heat treatment reactor and the vapors are vented; The non-vapor products of the catalytic pyrolysis reactor, or a portion of the gas remaining after removal of the desired products, or both, are combusted to provide energy for the pyrolysis or catalytic pyrolysis process; A solid co-reactant is fed into a thermal treatment reactor; the solid co-reactant material comprises one or more materials selected from agricultural lime, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, limestone, hydrotalcite, activated carbon, or zeolite, or other solid basic material, or any combination thereof; The solid co-reactant is transferred to a combustion regenerator where the carbonaceous material reacts with air and at least a portion of the hot solid co-reactant is returned to the thermal treatment reactor; The products produced in the pyrolysis reactor are transferred to a catalytic pyrolysis reactor containing a catalyst without separating most of the products; A gas phase co-reactant or recycle stream comprising H2, CO, olefins, or any combination thereof is fed directly to a pyrolysis reactor or catalytic pyrolysis reactor; A portion of the vapor product from the catalytic pyrolysis process is fed to a condenser where it is cooled to produce condensed material; A portion of the condensed material separated from the product stream from the pyrolysis or catalytic pyrolysis reactor is separated into fractions, at least a portion of which is recycled to the pyrolysis reactor; the condensed material is separated into fractions by distillation, and at least a portion of the paraffins, olefins, or aromatics containing more than 7 carbon atoms, or a combination thereof, is recycled to the pyrolysis or catalytic pyrolysis reactor; the condensed material separated from the product stream from the thermal cracking or catalytic pyrolysis reactor is separated into fractions by distillation, and at least a portion of the fraction boiling above 300°C or boiling in the range of 300-800°C is recycled to the thermal cracking or catalytic pyrolysis reactor; The catalytic reactor is a fluidized bed reactor; The catalytic reaction is carried out in a fluidized bed, circulating bed, bubbling bed, or riser reactor at an operating temperature ranging from 300°C to 800°C, 350°C to 750°C, 400°C to 700°C, 450°C to 650°C, 500°C to 600°C, or 525°C to 575°C; the pressure is at least 0.1 MPa (1 bar), at least 0.3 MPa (3 bar), or at least 0.4 MPa (4 bar), or 0.1-2.0 MPa (1-20 bar), 0.1-1.0 MPa (1-10 bar), or 0.3-0.8 MPa (3-8 bar), preferably 0.4-0.6 MPa (4-6 bar); The fluidizing gas for catalytic pyrolysis may comprise H2, CO, CO2, H2O, C1-C4 paraffins or olefins or both, N2, Ar, He, or recycle streams, or any combination thereof; The residence time of the fluidizing gas in the catalytic pyrolysis reactor (defined as the reactor volume divided by the volumetric flow rate of the fluidizing fluid under process conditions of temperature and pressure) can be from 1 second to 480 seconds, or from 1 second to 240 seconds, or from 2 seconds to 60 seconds, or from 3 seconds to 30 seconds, or from 4 seconds to 15 seconds; the catalyst is a solid catalyst, and the catalytic pyrolysis step comprises pyrolyzing in a fluidized bed reactor in the presence of the solid catalyst to produce a fluidized product stream and spent catalyst comprising coke, wherein at least 95% of the carbon in the feed is converted to coke and volatile products; the catalyst comprises a zeolite; the catalyst is selected from ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-50, or a combination thereof; the catalyst comprises ZSM-5; the product vapor mixture from the catalytic conversion comprises at least 20 wt. % olefins, or at least 50 wt. % olefins, in some embodiments in the range of 20 to 90 wt. % olefins; The catalyst composition comprises a crystalline molecular sieve characterized by an SAR of greater than 12 to 240 and a CI of 5 to 10; the mass yield of olefins in the product vapor mixture from the catalytic conversion is at least 30%, or at least 40%, or at least 45%, or at least 50%, or at least 55%, or at least 60%, or from 20% to 90%, or from 30% to 70%, or from 45% to 60% olefins based on the mass in the polymer feed; The mass yield of BTX in the gaseous product mixture from the catalytic conversion is at least 30%, or at least 40%, or at least 45%, or at least 50%, or at least 55%, or at least 60%, or from 20% to 90%, or from 30% to 70%, or from 45% to 60% BTX based on the mass in the polymer feed; The vapor products of catalytic pyrolysis are passed through one or more solids separation devices equipped with cyclones; The catalyst in the catalytic pyrolysis reactor is withdrawn, regenerated by oxidation with air, and returned to the catalytic pyrolysis reactor; Heat from catalyst regeneration provides energy for the thermal treatment or pyrolysis step; At least a portion of the gas in the product mixture is combusted in the regenerator; The gaseous catalytic pyrolysis product mixture is subjected to a separation process to produce a gas stream enriched in CH4, CO, and H2, and at least a portion of the gas stream enriched in CH4, CO, and H2 is passed to a regenerator where it is combusted; The gaseous catalytic pyrolysis product mixture contains CH4 and C2-C4 paraffins; 50-100 mass% of the CH4 and C2-C4 paraffins are combusted in the regenerator; at least 2, or at least 3, or at least 5, or at least 7, or at least 10, or at least 15, or 2 to 20, or 3 to 10, or 5 to 10 plastics upgrading facilities, i.e., pyrolysis and catalytic pyrolysis units feeding a central separation and refining facility; the total crude product mixture prepared in the at least two plastics upgrading facilities incorporated into the central separation and purification facility is at least 20, or at least 50, or at least 100, or at least 150, or at least 200 metric tons per day, or between 20 and 500, or between 30 and 200, or between 50 and 150 metric tons per day; A central facility for separation and purification exists at the refinery; and Benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6-C20 paraffins and olefins, ethylene, propylene, or naphthalene, or others, or any combination thereof, prepared from waste plastics at multiple facilities are separated and purified at a central separation and purification facility.

[0032] Chemical recycling of plastics by pyrolysis in a thermochemical reactor has many advantages, including the suitability of mixtures of all types of plastics, the long residence time in the pyrolysis reactor(s) ensures that the plastic pieces are heated to decomposition temperatures, eliminating the need to grind the plastic particles to small sizes, the ability to operate pyrolysis at high temperatures, and the ability to remove undesirable contaminants in an optional thermal treatment reactor.

[0033] Providing, installing, and / or operating a network of remote plastic pre-treatment facilities is advantageous for the collection of pre-treated waste plastics. For example, it allows the pre-treated waste plastics to be formed into sizes and shapes that are easier to handle, thereby improving the speed of operations. It also allows the pre-treated waste plastics to be transferred and fed directly into mobile storage containers, thereby improving collection rates by allowing relatively large batches of pre-treated waste plastics to be transported to a central processing facility (e.g., in a hub-and-spoke configuration). It also allows the waste plastic material to be sanitized, making it safer to transport and store than non-pre-treated material.

[0034] Providing, installing, and / or operating a remote pretreatment system and collecting pretreated plastics for transport to a centralized processing facility is advantageous for the centralized processing facility in that it merits a larger and / or more efficient processing system. For example, in the case of plastics upgrading, economies of scale dictate that a larger plant is advantageous for producing refined products, increasing plant efficiency, and increasing profitability. Furthermore, centralized processing facilities can be located adjacent to existing facilities, such as refineries or chemical plants, where the products of the plastics upgrade can be further separated and refined using existing equipment, along with or instead of petroleum-based materials. Sanitized pretreated materials make storage and handling of materials safer for central processing facility personnel, reduce environmental hazards and unwanted contaminants, and reduce the production of harmful odors and irritating vapors.

[0035] Another benefit of providing a decentralized plastic pretreatment process and a central facility for upgrading the pretreated plastics is that different plastic feedstocks contain mixtures of different materials, and such mixtures can be blended or mixed together at the central facility before processing, improving the operability of the central facility by providing a more homogeneous feedstock mixture to the facility. For example, waste plastic from one site may be rich in PVC, which contains chlorine and causes corrosion, while material from a second site may be almost PVC-free; the blend of the two sources can be processed at the central facility without damaging the equipment, while the PVC-rich material cannot.

[0036] An additional advantage of a decentralized pretreatment process is that similarly sized material from multiple pretreatment facilities can be more easily handled and mixed together to provide a more homogeneous feed for the upgrading process.

[0037] The use of a pelletizing process in a decentralized pretreatment system has the advantage of forming the material into a manageable size and shape for transport and metering in further processes. The pelletized material can also be more easily stored with less concern about degradation by chemical or biological processes or attack by pests such as insects, bacteria, fungi, or animals.

[0038] The advantages of the two-step plastics upgrading process include a simple system for feeding the raw pyrolysis products to the catalytic process; no risk of agglomeration in the fluidized bed that would cause bed defluidization or clumping; no need to thoroughly mix the solid or molten plastic feed with the catalyst particles; a significantly narrower residence time distribution of the pyrolysis gas in the catalytic reactor compared to the solid feed, resulting in fewer heavy products; no carryover of plastic particles to the catalyst regenerator; fewer external impurities transferred to the catalytic reactor; and, if the optional thermal treatment reactor is used, no inorganic particles such as fillers or additives embedded in the polymer are transferred to the catalytic reactor (fillers are usually alkaline (basic) and would react with acidic catalysts to cause deactivation); heat is supplied to the plastic convectively without the use of steam (which would cause catalyst deactivation (dealuminization)); and a greatly reduced need for added fluidization gas, making product recovery simpler and less expensive.

[0039] Another advantage of the two-step plastic upgrading process is that the production of the crude liquid product stream made from recycled plastics by the process of the present invention can be performed at a location separate from the product separation and purification system; this "decentralized processing" scheme minimizes separation and purification costs for small regional plastic upgrading facilities. [Brief explanation of the drawings]

[0040] [Figure 1]1 illustrates schematically a process for converting mixed plastic materials into valuable products by pyrolyzing the mixed plastics and catalytically reacting the raw product mixture to produce olefins, aromatics, or some combination thereof. [Figure 2] 1 shows a schematic of a process for converting mixed plastic materials into valuable products by pyrolyzing the mixed plastics and catalytically reacting the products to produce olefins, aromatics, or some combination thereof, using a thermal treatment reactor to remove contaminants before feeding the pyrolysis reactor. [Figure 3] 1 shows a schematic representation of an embodiment of the present invention in which five plastic upgrading units are connected in a hub and spoke system to feed one product separation and purification facility. [Figure 4] 1 shows a diagram of the reactor used in the examples. [Figure 5] A conceptual embodiment of a process for converting mixed plastic materials into valuable products in a decentralized system where pretreatment processes are carried out at various sites and catalytic pyrolysis and product upgrading, separation, and purification are carried out at one central site is shown. [Figure 6] A conceptual embodiment of a process for converting mixed plastic materials into valuable products in a decentralized system where pretreatment processes and catalytic pyrolysis are performed at various sites, and product upgrading, separation, and purification are performed at one central facility is shown. [Figure 7] 1 illustrates one embodiment of a pretreatment process for preparing waste plastics for catalytic upgrading. [Figure 8] 1 shows a general schematic of the flow profile and mixing behavior in a typical static mixer.

[0041] Glossary With respect to aromatics, as used herein, the terms "aromatic" or "aromatic compound" are used to refer to a hydrocarbon compound or compounds that contain one or more aromatic groups, such as, for example, monoaromatic 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-ethyltoluene, 3-ethyltoluene, 4-ethyltoluene, trimethylbenzene (e.g., 1,3,5-trimethylbenzene, 1,2,4-trimethylbenzene, 1,2,3-trimethylbenzene, etc.), ethylbenzene, styrene, cumene, methylbenzene, propylbenzene, xylene (e.g., p-xylene, m-xylene, o-xylene, etc.), naphthalene, methyl-naphthalene (e.g., 1-methylnaphthalene, anthracene, 9,10-dimethylanthracene, pyrene, phenanthrene, dimethyl-naphthalene (e.g., 1,5-dimethylnaphthalene, 1,6-dimethylnaphthalene, 2,5-dimethylnaphthalene, etc.), ethyl-naphthalene, hydrindene, methyl-hydrindene, dimethyl-hydrindene. Mono- and / or polycyclic aromatic compounds may also be produced in some embodiments.

[0042] With respect to fluids, the term "fluid" refers to a gas, a liquid, a mixture of a gas and a liquid, or a gas or liquid containing dispersed solids, liquid droplets, and / or bubbles. The terms "gas" and "vapor" have the same meaning and are sometimes used interchangeably. In some embodiments, it can be advantageous to control the residence time of the fluidizing fluid within the reactor. The fluidization residence time of the fluidizing fluid is defined as the volume of the reactor under process conditions of temperature and pressure divided by the volumetric flow rate of the fluidizing fluid.

[0043] Regarding fluidized bed reactors, the term "fluidized bed reactor" is given its conventional meaning in the art and is used to refer to a reactor that includes a vessel that can contain particulate solid material (e.g., silica particles, catalyst particles, etc.), where a fluid (e.g., gas or liquid) passes through the particulate solid material at a velocity sufficient to suspend the solid material and cause it to behave as if it were a fluid. Examples of fluidized bed reactors are described in "Fluidization Engineering" by D. Kunii and O. Levenspiel, Butterworth-Heinemann, 1991, which is incorporated herein by reference. The term "circulating fluidized bed reactor" is also given its conventional meaning in the art and is used to refer to a fluidized bed reactor in which the particulate solid material exits the reactor, circulates through a line in fluid communication with the reactor, and is recycled back to the reactor. Examples of circulating fluidized bed reactors are described in "Fluidization Engineering" by D. Kunii and O. Levenspiel, Butterworth-Heinemann, 1991.

[0044] Bubbling fluidized bed reactors and turbulent fluidized bed reactors are also known to those skilled in the art. In a bubbling fluidized bed reactor, the fluid stream used to fluidize the particulate solid material operates at a flow rate low enough that bubbles and voids are observed within the volume of the fluidized bed during operation. In a turbulent fluidized bed reactor, the flow rate of the fluid stream is higher than that used in a bubbling fluidized bed reactor, so that bubbles and voids are not observed within the volume of the fluidized bed during operation. Examples of bubbling and turbulent fluidized bed reactors are described in Kirk-Othmer Encyclopedia of Chemical Technology (online), Vol. 11, Hoboken, NJ: Wiley-Interscience, 2001, pages 791-825 (incorporated herein by reference).

[0045] Olefin: The term "olefin" or "olefinic compound" (also known as "alkene") is given its ordinary meaning in the art and is used to refer to any unsaturated hydrocarbon containing one or more pairs of carbon atoms joined by a double bond. Olefins include both cyclic and acyclic (aliphatic) olefins, where the double bond is located between carbon atoms that form part of a cyclic (closed ring) or open-chain group, respectively. Furthermore, olefins can contain any suitable number of double bonds (e.g., monoolefins, diolefins, triolefins, etc.). Examples of olefinic compounds include, but are not limited to, ethene, propene, allene (propadiene), 1-butene, 2-butene, isobutene (2-methylpropene), butadiene, and isoprene, among others. Examples of cyclic olefins include cyclopentene, cyclohexane, and cycloheptene, among others. Aromatic compounds, such as toluene, are not considered olefins, but olefins containing an aromatic moiety, such as benzyl acrylate or styrene, are considered olefins.

[0046] Regarding catalysts, catalytic components useful in the context of the present invention can be selected from any catalyst known in the art or understood by those skilled in the art. A catalyst promotes and / or influences a reaction. Thus, as used herein, a catalyst lowers the activation energy (increases the rate) of a chemical process and / or improves the distribution of products or intermediates in a chemical reaction (e.g., shape-selective catalysis). Examples of reactions that can be catalyzed include dehydration, dehydrogenation, isomerization, hydrogen transfer, hydrogenation, polymerization, cyclization, desulfurization, denitrogenation, deoxygenation, aromatization, decarbonylation, decarboxylation, aldol condensation, and combinations thereof. The catalytic components can be considered acidic, neutral, or basic, as would be understood by those skilled in the art.

[0047] For catalytic pyrolysis, particularly advantageous catalysts include those containing internal porosity selected according to pore size (e.g., mesoporous and microporous sizes typically associated with zeolites) (e.g., average pore sizes of less than about 10 nm, less than about 5 nm, less than about 2 nm, less than about 1 nm, less than about 0.5 nm, or even smaller). In some embodiments, catalysts having average pore sizes of about 0.5 nm to about 10 nm can be used. In some embodiments, catalysts having average pore sizes of about 0.55 nm to about 0.65 nm, or about 0.59 nm to about 0.63 nm can be used. In some examples, catalysts having average pore sizes of about 0.7 nm to about 0.8 nm, or about 0.72 nm to about 0.78 nm can be used.

[0048] In some preferred embodiments of catalytic pyrolysis, the catalyst may be selected from natural zeolites, synthetic zeolites, and combinations thereof. In certain embodiments, the catalyst may be a ZSM-5 zeolite catalyst, as will be understood by those skilled in the art. Optionally, such catalysts may contain acidic sites. Other types of zeolite catalysts include ferrierite, zeolite Y, zeolite beta, mordenite, MCM-22, ZSM-23, ZSM-57, SUZ-4, EU-1, ZSM-11, (S)AlPO-31, and SSZ-23, among others. Zeolites and other small pore materials are often characterized by their constraint index. The constraint index approximates the ratio of the cracking rate constants for normal hexane and 3-methylpentane. A method for determining the constraint index is described in more detail in U.S. Pat. No. 4,029,716 (the details of this method are incorporated by reference).

[0049] Constraint Index (CI) values ​​for some typical materials are as follows: [Table 1]

[0050] The CI can vary within the indicated range of 1 to 12. Similarly, other variables, such as crystal size or the presence of potentially occluded exhaust contaminants and binders intimately associated with the crystals, can also affect the CI. Those skilled in the art will understand that the CI utilized herein, while providing a very useful means for characterizing the molecular sieves of interest, is approximate given the method of determination, and that extreme values ​​may be compounded in some cases. However, the CI will have a value within the approximate range of 1 to 12 for any given molecular sieve useful herein.

[0051] In other embodiments, non-zeolitic catalysts such as WOx / ZrO2, aluminum phosphate, etc. may be used. In some embodiments, the catalyst may contain a metal and / or metal oxide. Suitable metals and / or oxides include, among others, nickel, palladium, platinum, titanium, vanadium, chromium, manganese, iron, cobalt, zinc, copper, gallium, and / or any of their oxides. In some examples, promoter elements selected from rare earth elements, i.e., oxides of elements 57-71, cerium, zirconium, or combinations thereof, may be included to modify the activity or structure of the catalyst. Furthermore, in some cases, the properties of the catalyst (e.g., pore structure, type and / or number of acid sites, etc.) may be selected to selectively produce desired products.

[0052] Catalysts for other processes (e.g., olefin alkylation, aromatization (hydrocarbon reforming), hydrogenation, hydrotreating, deoxygenation, denitrogenation, and desulfurization) are well known and can be selected for the olefin conversion or other processes described herein.

[0053] Hub and Spoke: A hub and spoke system consists of a centralized processing center (the hub) and multiple pre-processing centers (the spokes), which send at least a portion of the processed material to the hub for further processing.

[0054] Plastic or Polymer: The terms "plastic" and "polymer" are used interchangeably herein. A polymer is a carbon-based (at least 50% by weight C) material composed primarily of repeating units and having a number average molecular weight of at least 100, typically greater than 1000, or greater than 10,000. Polymers include thermoplastic polymers such as polyethylene, polypropylene, polyester, polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene (ABS) copolymer, polyamide, polyurethane, polyether, polycarbonate, poly(oxide), poly(sulfide), polyarylate, polyetherketone, polyetherimide, polysulfone, polyurethane, polyvinyl alcohol, as well as polymers produced by polymerization of monomers such as dienes, olefins, styrene, acrylates, acrylonitrile, methacrylates ... Examples of suitable feedstocks include nitrile, diacids and diols, lactones, diacids and diamines, lactams, vinyl halides, vinyl esters, their block copolymers, and their alloys; thermosetting polymers, such as epoxy resins; phenolic resins; melamine resins; alkyd resins; vinyl ester resins; unsaturated polyester resins; crosslinked polyurethanes; polyisocyanurates; crosslinked elastomers (including, but not limited to, polyisoprene, polybutadiene, styrene-butadiene, styrene-isoprene, and ethylene-propylene-diene monomer polymers); and blends thereof. Mixtures of polymers separated from municipal solid waste or other waste streams are suitable feedstocks, provided they contain only small percentages of contaminants (e.g., S, N, O, halogens, minerals, metals, or carbon black). Polymers that produce halides upon pyrolysis, such as polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), and other halogenated polymers, are generally minimized or eliminated from the useful feedstocks of this invention.

[0055] Pretreatment: As used herein, the term "pretreatment" includes any process performed to prepare waste plastics for catalytic pyrolysis or other upgrading processes. Some processes that can be part of the pretreatment process include: 1) separation or grading by material type (which serves to selectively remove some undesirable materials and make the feed mixture more homogeneous); 2) washing (which may involve solvents or water or aqueous solutions to remove dirt, organic materials attached to the plastic, labels, etc.); 3) drying (removal of water or other solvents or volatile materials); 4) sizing (cutting or grinding or reducing the size of larger particles to a size suitable for further processing); and 5) contaminant removal (which can be thermal or chemical or both to reduce elements other than carbon and hydrogen, particularly halides, F, Cl, Br, or I, nitrogen, oxygen, sulfur, or metals, or a combination of these elements). The pretreatment process can include any process selected from collecting, separating, mixing, decontaminating, dechlorinating, dehalogenating, desulfurizing, distilling, oxidation, hydrotreating, pyrolysis, washing, sizing, melting, pelletizing, filtering, drying, or a combination thereof.

[0056] Pyrolysis: The terms "pyrolysis" and "pyrolyzing" have their conventional meaning in the art and are used to refer to the conversion of compounds (e.g., solid hydrocarbonaceous materials) into one or more other substances (e.g., volatile organic compounds, gases, and coke) by heat, preferably without or in the absence of added O2. Preferably, the volume fraction of O2 present in the pyrolysis reaction chamber is 0.5% or less. Pyrolysis can be carried out with or without the use of a catalyst. "Catalytic pyrolysis" refers to pyrolysis carried out in the presence of a catalyst and can include steps as described in more detail below. Examples of catalytic pyrolysis processes are reviewed, for example, in Huber, G. Wet et al., "Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysts, and Engineering," Chem. Rev. 106, (2006), pp. 4044-4098.

[0057] "Residence time" is defined as the volume of a reactor or device, or a particular portion of a device, divided by the outlet flow rate of all materials (including fluidizing gas, product, and impurities) exiting the reactor, or device, or portion of the reactor or device, measured or calculated at the average temperature of the reactor or device and the outlet pressure of the reactor or device or portion thereof.

[0058] "Thermal treatment" is used herein as a process to heat the feed mixture to a moderate temperature that generates and vents some contaminants such as HCl, H2S, and NH3, and melts the feed mixture so that solids such as minerals, metals, and carbon black can be removed by filtration.

[0059] As in standard patent terminology, the term "comprising" means "including" and does not exclude additional elements. Any aspect of the invention described in connection with the term "comprising" also includes narrower embodiments in which the term "comprising" is replaced with the narrower terms "consisting essentially of" or "consisting of." As used herein, the terms "includes" or "including" should not be construed as limiting the invention, but rather as listing exemplary elements. DETAILED DESCRIPTION OF THE INVENTION

[0060] FIG. 1 shows a schematic diagram of the process of the present invention for converting waste plastics to olefins and aromatics. A plastic mixture 10 is introduced into an optional feed system 100, which prepares the plastic mixture for introduction into the process by, for example, removing undesired feed materials 102, such as metals, minerals, and halogenated materials, and / or sizing the materials to a desired size range. The undesired feed material removal and sizing steps can be performed in any order, i.e., one step can be performed first and the other step can be performed second. The remaining plastic mixture 101 is passed to an optional washing process 110, where the plastic mixture can be cleaned, for example, by treatment with a washing solution 112 to remove unwanted materials (e.g., dirt, labels, or coatings) to produce a cleaned plastic mixture 111 and a spent solution 113. The plastic mixture 111 is passed to a pyrolysis reactor 120. Optionally, a gas-phase co-reactant, or recycle stream, including H, CO, or olefins, or some combination thereof, can be fed directly to the pyrolysis reactor 120 or catalytic pyrolysis reactor 140 (not shown). In the pyrolysis reactor 120, the mixture is heated to a temperature that will crack the plastic into a product mixture including a combination of gaseous, solid, and liquid phases. Without separation, at least a portion of the raw pyrolysis product mixture 121 is passed to the catalytic reactor 140 while maintaining the temperature of the pyrolysis product mixture at least at the temperature it was at when it exited the pyrolysis reactor 120. The pyrolysis product mixture 121 is passed to the hot catalytic reactor 140 charged with an aromatization catalyst effective to convert paraffins or olefins, or both, to aromatics, shown as catalytic product 141. A portion of the catalyst 142 may be continuously withdrawn from the reactor 140, separated from product 141, or both, and passed to a catalyst regenerator 150. In the catalyst regenerator 150, the catalyst is oxidized by treatment with an oxygen source such as air 151, the regenerated catalyst 143 is returned to the reactor 140, and the combustion product gases 152 are vented or used to provide heat to the pyrolysis reactor(s).The catalyst product 141 can be separated into components such as ethylene, propylene, butenes, C1-C5 paraffins, benzene, toluene, xylenes, naphthalene, and other fractions in a separation scheme using conventional separation techniques. A portion of the material separated from the catalyst product stream 141 can be recycled to the pyrolysis reactor 120 or the catalytic pyrolysis reactor 140, or both.

[0061] 2 shows a schematic diagram of another embodiment of the process of the present invention for converting waste plastics to olefins and aromatics. The plastic mixture 10 is introduced into an optional feed system 100, which prepares the plastic mixture for introduction into the process by, for example, removing undesired feed materials 102, such as metals, minerals, and halogenated materials, and / or sizing the materials to a desired size range. The undesired feed material removal and sizing steps can be performed in any order, i.e., one step can be performed first and the other step can be performed second. The remaining plastic mixture 101 is passed to an optional washing process 110, where the plastic mixture can be cleaned, for example, by treating it with a washing solution 112 to remove unwanted materials (e.g., dirt, labels, or coatings) to produce a cleaned plastic mixture 111 and a spent solution 113. The prepared plastic mixture 111 is passed to a thermal treatment reactor 115 with an optional co-reactant 122, such as a heat transfer medium or getter, where the mixture is heated to an intermediate temperature to partially decompose the plastic, for example, decomposing PVC or PVDC to release HCl, or decomposing another halogenated polymer to release HCl, HBr, or HI, or releasing vapors such as NH, HO, etc. An optional sweep gas 124 (e.g., HO, N, Ar, CO, or some combination thereof) is supplied to the thermal treatment reactor 115 to aid in the removal of vapors generated therein, which are vented through an outlet port 125. With or without the sweep gas, the vapor 125 can be treated to capture or neutralize HCl and toxic materials before being released or transferred to water treatment. The vapor 125 typically contains at least 60% or at least 80% HO and may also contain HCl, halocarbon compounds, and other species that are more volatile than the molten polymer. The condensed phase 126 is passed to the pyrolysis reactor 120 where it is heated and decomposed into a product mixture comprising a combination of solid, liquid, and gas phases.While maintaining the temperature of the pyrolysis product mixture at least at the temperature at which it exited the pyrolysis reactor 120, the raw product mixture 121 is passed to a high-temperature catalytic reactor 140, which is charged with an aromatization catalyst effective to convert paraffins, olefins, or both, to aromatics (designated catalyst product 141). A portion of the catalyst 142 can be continuously withdrawn from the reactor 140, separated from the product 141, or both, and passed to a catalyst regenerator 150. In the catalyst regenerator 150, the catalyst is oxidized by treatment with an oxygen source, such as air 151, and the regenerated catalyst 143 is returned to the reactor 140, while the combustion product gases 152 are vented or used to provide heat to the pyrolysis reactor(s). The catalyst product 141 can be separated into components such as ethylene, propylene, butenes, C1-C5 paraffins, benzene, toluene, xylenes, naphthalene, and other fractions in a separation scheme using conventional separation techniques. A portion of the material separated from the catalytic product stream 141 can be recycled to the pyrolysis reactor 120 or the catalytic pyrolysis reactor 140, or both.

[0062] Combustible gases (e.g., methane, ethane, propane, butane, CO, and H) can optionally be recovered from vapor stream 125 or from gases produced in catalytic pyrolysis in the fluidized bed reactor. The combustible gases can provide heat for the process. Heat in reactor 115 or 120 can also be provided by pressure / friction and / or other heat sources (e.g., resistive or inductive heating).

[0063] When recycled polymeric materials are used, impurities can optionally be removed from the feed composition before being fed to the reactor (e.g., by an optional separation step, such as 100 in FIG. 1 or 2). In some cases, the separation step can include mechanical separation, sink-float separation, air sieving, or other known separation processes, preferably in an automated mode. In some cases, the particle size of the solid polymeric feed composition can be reduced in a size reduction system as part of 100 before passing the feed to the thermal treatment or pyrolysis reactor. In some embodiments, the mean diameter of the size-reduced feed composition exiting the size reduction system can include about 50% or less, about 25% or less, about 10% or less, about 5% or less, or about 2% or less of the mass mean diameter of the feed composition fed to the size reduction system. The feed mixture can include a plastic mixture in which at least 85%, or at least 90%, or at least 95% by weight of the particles pass through a 0.25 inch (0.6 cm), or 0.5 inch (1.2 cm), or 1.0 inch (2.5 cm), or 1.5 inch (3.7 cm), or 2 inch (5.0 cm), or 4 inch (10.0 cm) screen. The average diameter (size) can be determined by sieving through a mesh (screen). Large particle feed materials can be easier to transport and less difficult to process than small particle feed materials. However, in some cases it may be advantageous to feed small particles to the reactor. A size reduction system can be used to transport large particle feed between the source and the process while allowing small particles to be fed to the reactor.

[0064] Feed materials suitable for use in the present invention include polyethylene (PE), polypropylene (PP), polyacetylene, polybutylene, polyolefin, polyethylene terephthalate (PET), polybutylene terephthalate, polyester, copolyester, polycarbonate, polyurethane, polyamide, polystyrene (PS), polyacetal, epoxy, polycyanurate, polyacrylic acid, polyurea, vinyl ester, polyacrylonitrile, polyamide, polyurethane, polyether, polycarbonate, poly(oxide), poly (sulfides), polyarylates, polyetherketones, polyetherimides, polysulfones, polyurethanes, polyvinyl alcohol, polyvinyl chloride (PVC), polyvinyl dichloride (PVDC), polyvinyl acetate, nylon, copolymers such as ethylene-propylene, acrylonitrile-butadiene-styrene (ABS), nitrile rubber, natural and synthetic rubber, tires, styrene-butadiene, styrene-acrylonitrile, styrene-isoprene, styrene-maleic anhydride, ethylene vinyl acetate, nylon 12 / 6 / 66, The present invention can include all types of polymeric materials, including filled polymers, polymer composites, plastic alloys, other polymeric materials, and polymers or plastics dissolved in solvents (even those obtained as waste or discarded materials from polymer or plastic manufacturing processes), post-consumer recycled polymeric materials, materials separated from waste streams such as municipal solid waste, and polymers produced by polymerization of monomers such as dienes, olefins, styrenes, acrylates, acrylonitrile, methacrylates, methacrylonitrile, diacids and diols, lactones, diacids and diamines, lactams, vinyl esters, block copolymers thereof, and alloys thereof, thermosetting polymers such as epoxy resins, phenolic resins, melamine resins, alkyd resins, vinyl ester resins, unsaturated polyester resins, crosslinked polyurethanes, polyisocyanurates, and crosslinked elastomers (including, but not limited to, polyisoprene, polybutadiene, styrene-butadiene, styrene-isoprene), or any combination thereof. The present invention includes subcombinations of these materials as desired or available from a particular location.The present invention can be described as comprising one or any combination of these materials.

[0065] In either method, the thermal treatment reactor 115 or the pyrolysis reactor 120, or two or more of them, can be moving-bed reactors in which the feedstock is propelled along the length of the reactor by mechanical or gravitational means, or by both mechanical and gravitational means. Typical examples of reactors suitable for the thermal treatment reactor 115 or the pyrolysis reactor 120 include single-screw extruders, twin-screw extruders, auger reactors, rotary kiln reactors, or stepped grate reactors. The pyrolysis reactor can have multiple heating zones (with subsequent zones having increasing temperatures). The pyrolysis reactor can be equipped with gas outlets in areas of the reactor where the temperature of the material within the reactor is below 300°C or between 250°C and 300°C, allowing products (e.g., water vapor, HCl, NH3, or other materials) produced at low temperatures to be removed from the reactor. A separating screen is installed in the pyrolysis reactor immediately downstream of the gas outlet to at least partially prevent gases evolved at lower temperatures from passing through the hotter sections of the reactor along with the molten and solid materials. A gas inlet for introducing hot inert or recycle gas (e.g., gases containing CH, H, CO, CO, and any of C-C paraffins or olefins, or mixtures) can be installed immediately downstream of the gas vent and optional screen.

[0066] Optionally, a solid co-reactant 122 (e.g., CaO, MgO, hydrotalcite, activated carbon, or zeolite, or some combination thereof) that captures or removes undesirable components can be fed to the heat treatment reactor 115 and separated therefrom by filtration through a screen.

[0067] When the auger reactor is utilized for thermal processing or pyrolysis, a helical auger is optionally used, with different pitch dimensions at different portions of the auger, to adjust the velocity of the condensed phase from the inlet to the outlet of the reactor. The flight thickness and shaft diameter may be variable along the length of the auger to control the flow rate of the vapor and condensed phase. Augers with paddles, cut, or folded flights are also contemplated within the scope of the present invention.

[0068] Rotary kiln reactors can be used for thermal treatment or pyrolysis. The kiln cylinder can be equipped with lifters, such as helical lifters attached to the cylinder wall or plate-shaped lifters, folding lifters, or segmented lifters extending from the cylinder wall. Rotary kiln reactors contemplated herein can also be tilted upward or downward toward the exit end of the kiln, depending on the desired residence time and flow rate of the condensed phase within the kiln, using gravity to control the residence time of the condensed phase. Rotary kiln reactor rotation rates can also be adjusted as desired (e.g., from 20 revolutions per minute to 0.2 revolutions per minute) to achieve thorough mixing and high heat transfer, depending on the nature of the feed mixture and added co-reactants. Rotary kiln reactors contemplated herein can be externally heated by combustion of waste process gases (e.g., CH4, C2-C4 paraffins, H2, CO, etc., recycled from product separations or natural gas) or electrically.

[0069] In either embodiment, the temperature profile within the pyrolysis reactor can range from a low temperature near the feed inlet port to a high temperature at the outlet port(s). For example, the temperature range can be 20°C to 225°C (e.g., 20°C to 100°C or 20°C to 50°C) at or near the inlet port, and 300°C to 700°C (e.g., 325°C to 650°C, 350°C to 600°C, or 350°C to 575°C) at the high temperature outlet port.

[0070] The solid co-reactant fed to the thermal treatment reactor can optionally be transferred to a combustion regenerator where the carbonaceous material reacts with air and at least a portion of the hot solid co-reactant is returned to the thermal treatment reactor. The hot flue gas exiting the solid co-reactant regenerator can be passed to a catalytic heater for heating the catalyst in the catalytic pyrolysis reactor.

[0071] After exiting the heat treatment reactor 115, the raw product preferably does not come into contact with any cold surfaces that could condense the product, and surfaces are preferably maintained at at least 300°C, at least 325°C, or at least 350°C, or within 25°C or 50°C of the temperature at which it exits the reactor 115. Preferably, in either embodiment, the temperature of the mixture is maintained at a temperature at least 2°C, or at least 3°C, or at least 5°C, or at least 10°C higher than the temperature of the mixture at the exit end of the heat treatment reactor.

[0072] In either embodiment of the invention, the catalytic reactor 140 can be a fluidized-bed reactor, the catalyst is a solid catalyst, and the catalytic pyrolysis step includes pyrolyzing in the presence of the solid catalyst in the fluidized-bed reactor to produce a fluidized product stream 141 and coke-containing spent catalyst 142, where at least a portion of the coke-containing spent catalyst is transferred to a regenerator 150 where the coke reacts with oxygen or air to form hot regenerated catalyst, and returning at least a portion of the hot regenerated catalyst 143 to the fluidized-bed reactor, where heat from the hot regenerated catalyst provides energy for the catalytic pyrolysis step. In either method, vapors exiting the catalytic pyrolysis reactor can be passed through an optional solids separation device (e.g., a cyclone or screen) to remove entrained solids. These entrained solids can be passed to a catalyst regenerator, at least a portion can be returned to the catalytic pyrolysis reactor, disposed of, or some combination thereof.

[0073] In either method, the catalytic pyrolysis step can include pyrolysis in the presence of a fluidized bed catalyst. The catalytic pyrolysis reactor can comprise a fluidized bed, circulating bed, bubbling bed, or riser reactor operating at temperatures ranging from 300°C to 800°C, 350°C to 750°C, 400°C to 700°C, 450°C to 650°C, 500°C to 600°C, or 525°C to 575°C. The vapor residence time in the catalytic pyrolysis can be 1 second to 480 seconds, 1 second to 240 seconds, 2 seconds to 60 seconds, 3 seconds to 30 seconds, or 4 seconds to 15 seconds. The pressure of the catalytic pyrolysis may be at least 0.1 MPa (1 bar), at least 0.3 MPa (3 bar), or at least 0.4 MPa (4 bar), or 0.1 to 2.0 MPa (1 to 20 bar), 0.1 to 1.0 MPa (1 to 10 bar), or 0.3 to 0.8 MPa (3 to 8 bar), preferably 0.4 to 0.6 MPa (4 to 6 bar), the pressure being absolute.

[0074] The design and conditions of the fluidized bed catalytic reactor may be conventional. A fluidizing gas may be required at start-up. During steady-state operation, the fluidizing gas may optionally comprise a portion of the vapor separated from stream 126, which may be piped to the bottom of the fast catalytic pyrolysis fluidized bed reactor. Recycle gas from the process may be used as the fluidizing gas. The fluidizing gas may comprise H, CO, CO, H0, C1-C4 paraffins or olefins or both, N, Ar, He, or a recycle stream, or some combination thereof.

[0075] For catalytic pyrolysis, useful catalysts include those containing internal porosity selected according to pore size (e.g., mesoporous and microporous, typically associated with zeolites) (e.g., average pore diameters of less than 10 nm, less than 5 nm, less than 2 nm, less than 1 nm, less than 0.5 nm, or even smaller). In some embodiments, catalysts having average pore diameters of 0.5 to 10 nm can be used. In some embodiments, catalysts having average pore diameters of 0.5 to 0.65 nm, or 0.59 to 0.63 nm can be used. In some examples, catalysts having average pore diameters of 0.7 to 0.8 nm, or 0.72 to 0.78 nm can be used.

[0076] Particularly advantageous catalyst compositions for the catalytic pyrolysis fluidized-bed reactor of the present invention include crystalline molecular sieves characterized by an SAR (silica to alumina, SiO:AlO mass ratio) greater than 12 or between 12 and 240 and a CI (constraint index) between 1 and 12. Non-limiting examples of these crystalline molecular sieves include those having the structure of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-50, or combinations thereof. In one embodiment, the catalyst composition includes a crystalline molecular sieve characterized by an SAR greater than 12 to 240 and a CI between 5 and 10, such as molecular sieves having the structure of ZSM-5, ZSM-11, ZSM-22, ZSM-23, or combinations thereof. Methods for determining CI are more fully described in U.S. Pat. No. 4,029,716, the details of which are incorporated herein by reference.

[0077] The molecular sieve used herein, or a catalyst composition containing the same, can be heat-treated at elevated temperatures. This heat treatment is typically carried out by heating at a temperature of at least 370°C for at least 1 minute and generally up to 20 hours (typically in an oxygen-containing atmosphere, preferably air). Although subatmospheric pressures may be used for the heat treatment, atmospheric pressure is preferred for reasons of convenience. The heat treatment can be carried out at temperatures up to about 925°C. The heat-treated product is particularly useful in the process of the present invention.

[0078] For the catalyst compositions useful in the present invention, suitable molecular sieves can be used in combination with a carrier or binder material, such as a porous inorganic oxide carrier or a clay binder. Non-limiting examples of such binder materials include alumina, zirconia, silica, magnesia, thoria, titania, boria, and combinations thereof, typically in the form of dry inorganic oxide gels and gelatinous precipitates. Suitable clay materials include, by way of example, bentonite, diatomaceous earth, and combinations thereof. The relative proportion of suitable crystalline molecular sieves in the overall catalyst composition can vary widely, with molecular sieve content ranging from 30 to 90 weight percent of the composition, more typically from 40 to 70 weight percent. The catalyst composition can be in the form of extrudates, beads, or free-flowing microspheres.

[0079] The molecular sieves for use herein or catalyst compositions containing same may be at least partially replaced by ion exchange with hydrogen, or hydrogen precursor cations, or non-noble metal ions of Group VIII of the Periodic Table, i.e., nickel, iron, or cobalt, or zinc, or gallium, or combinations thereof, according to techniques well known in the art.

[0080] A portion of the vapor product from the catalytic pyrolysis process can be fed to a condenser where it is cooled to produce a condensed material. A portion of the condensed material can be separated into fractions, with at least a portion of the condensed material being recycled to the thermal cracking reactor or catalytic pyrolysis reactor. The condensed material can be separated into fractions by distillation, with at least a portion of the fraction boiling above 300°C or boiling in the range of 300-800°C being recycled to the thermal cracking or catalytic pyrolysis reactor. The condensed material can be separated into fractions by distillation, with at least a portion of the paraffins, olefins, or aromatics, or combinations thereof, containing more than 7 carbon atoms being recycled to the thermal cracking or catalytic pyrolysis reactor.

[0081] In a process in which catalyst from catalytic pyrolysis is regenerated, coke, charcoal, and other materials are oxidized in a catalyst regenerator to generate heat for use in the process or for conversion to export electricity. The oxidant can be supplied to the regenerator via stream 151 in FIG. 1 . The oxidant can originate from any source, including, for example, an oxygen tank, atmospheric air, or steam, among others. In the regenerator, the catalyst is reactivated and heat is generated by reacting with the oxidant. The solid mixture containing the deactivated catalyst can contain residual carbon and / or coke, as well as coke or char from the process, which can be removed via reaction with the oxidant in the regenerator. In some embodiments, a portion of the gaseous products from the catalytic pyrolysis process are supplied to a catalyst regenerator for combustion with the solid materials. The gaseous products are first separated into an olefin-rich stream and an olefin-lean stream, and at least a portion of the olefin-lean stream can be supplied to the catalyst regenerator. The regenerator in FIG. 1 includes a vent stream 152, which can contain regeneration reaction products, residual oxidant, etc.

[0082] In some embodiments of the process, at least a portion of the solid material 123 removed from the thermal treatment reactor 115 can be recycled to the feed of the thermal treatment reactor 115 as part of the optional co-reactant 122. In some embodiments of the process, the optional co-reactant 122 can include a solid material that reacts with a sulfur or nitrogen compound to capture the sulfur or nitrogen species in the solid phase. The solid material in the optional co-reactant 122 can include one or more materials selected from agricultural lime, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, limestone, or hydrotalcite, activated carbon, or zeolite, or some combination thereof.

[0083] Waste plastics are collected at numerous local facilities, each handling a small amount of plastic per day, either as part of municipal solid waste or as a separate recycling stream. In either case, most of the material becomes part of the 25 million tons of plastic sent annually to one of the more than 2,600 landfills in the United States. The amount of waste plastics available at any one site is typically only a few tens of metric tons per day.

[0084] Chemical plastic recycling plants include feed handling, cleaning, processing (e.g., thermal cracking and catalytic pyrolysis), recovery, separation, and purification operations. Separation and purification facility costs often account for 35-50% of the overall facility capital cost.

[0085] Smaller capacity plants cost more per ton of product than larger plants due to a lack of economies of scale. One way to take advantage of economies of scale in separation and purification functions is to network together multiple plants that produce a crude mixture of liquid products of similar composition and send the crude mixture to a refinery or other central processing facility for separation and purification into chemical-grade materials.

[0086] Some commercial plastics upgrading processes produce liquid products that are not suitable for separation and purification due to the presence of long-chain hydrocarbons and olefins; such products must be further upgraded by hydrotreating, such as in a hydrocracker, hydrotreater, steamcracker, or some combination thereof. While hydrotreating requires a hydrogen source, the products of the process of the present invention require little or no hydrogen for upgrading and can be separated and purified without hydrotreating. In addition, heating the feed for hydrotreating requires added energy that cannot be fully recovered, which is avoided in the present invention. Because hydrotreating is exothermic, significant heat is released in the process, which can cause problems with heat removal if the level of olefins is too high for the system's heat removal capacity.

[0087] An advantage of the present invention, a two-step process for upgrading plastics by pyrolysis followed by catalytic pyrolysis, is the ability to produce a liquid product suitable for combination with conventional refinery streams (e.g., steam cracker or hydrocracker products), which can be more easily stored and transported for separation and purification at larger facilities than gaseous products. This means that the crude liquid product stream made from recycled plastics by the process of the present invention can be produced at a location separate from the product purification system; this "decentralized processing" scheme can be advantageous for small, regional facilities, as it can minimize separation and purification costs.

[0088] FIG. 3 illustrates an embodiment of the present invention in which five plastic upgrading units 200 are connected in a hub-and-spoke system to feed one product separation and purification facility 210 .

[0089] In some embodiments, a system for upgrading waste plastics includes a first pyrolysis reactor and a catalytic fluidized bed reactor that together form one spoke in a "hub-and-spoke" network for producing purified chemical intermediates (e.g., benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6-C20 paraffins and olefins, ethylene, propylene, naphthalene, or others, or any combination thereof), with each of the multiple plastic upgrading facilities (spokes) producing a condensed phase product that is sent to a central processing facility (hub) for separation and purification into product streams. In some embodiments of the system, the number of plastic upgrading facilities that can be present in the network feeding one central separation and purification facility can be at least 2, at least 3, at least 5, at least 7, at least 10, or at least 15, or 2 to 20, 3 to 10, or 5 to 10 plastic upgrading facilities. The total crude product mixture prepared in the at least two plastics upgrading facilities incorporated into the central separation and purification facility can be at least 20, at least 50, at least 100, at least 150, or at least 200 metric tons per day, or from 20 to 500, 30 to 200, or 50 to 150 metric tons per day.

[0090] In some embodiments, a system for upgrading plastics includes a first pyrolysis reactor as one "spoke" in a "hub-and-spoke" network for producing purified chemical intermediates (e.g., benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6-C20 paraffins and olefins, ethylene, propylene, naphthalene, or others), where each of the multiple plastic upgrading sites (spokes) produces a condensed phase product that is sent to a central processing facility (hub) that includes a central fluidized-bed catalytic processing plant (Plas-TCat™) and separation and purification into product streams. In some embodiments of the system, the number of plastic pyrolysis facilities that can be present in the network feeding one central catalytic upgrading, separation, and purification facility can be at least 2, at least 3, at least 5, at least 7, at least 10, or at least 15, or 2 to 20, 3 to 10, or 5 to 10 plastic pyrolysis facilities. The total crude product mixture prepared in the plastic pyrolysis facility that is introduced into the central catalyst upgrading, separation, and refining facility can be at least 20, at least 50, at least 100, at least 150, or at least 200 metric tons per day, or from 20 to 500, 30 to 200, or 50 to 150 metric tons per day of crude product mixture.

[0091] Figure 5 shows a schematic diagram of the process of the present invention for converting waste plastics to olefins, aromatics, and other valuable products using a decentralized feed pretreatment system in which plastics are pretreated and catalytically pyrolyzed at multiple sites and the products further processed at a central site. There are three facilities in the diagram where waste plastics are recovered, pretreated, and catalytically pyrolyzed to produce valuable products. In some embodiments, there are two or more, or as many as 15, sites that perform pretreatment and catalytic pyrolysis, from which the catalytic pyrolysis products are transported to a central site where any combination of upgrading, separation, and / or purification occurs to produce products. The site where the combined products are further processed may be at or adjacent to a refinery or chemical plant, or may be a dedicated processing plant, and the materials may be co-processed with materials from other sources, including renewable and / or fossil resources. FIG. 6 illustrates an alternative form of the process of the present invention for converting plastic waste to olefins, aromatics, and other valuable products using a decentralized feed pretreatment system in which plastics are pretreated at multiple sites and the treated material is further processed at a central site.

[0092] The configurations of Figures 5 and 6 can be combined so that material pretreated and catalytically pyrolyzed at a distributed site (e.g., Site 1, Site 2, or Site 3 of Figure 5) is combined with the product of catalytic pyrolysis at Site 4 of Figure 6 for product upgrading, separation, and purification at a central facility. Thus, the feed to the central product upgrading, separation, and purification can be a combination of material pretreated and catalytically pyrolyzed in a distributed system such as Figure 5 and material pretreated in the distributed system of Figure 6 and catalytically pyrolyzed at a central catalytic pyrolysis facility for product upgrading, separation, and purification.

[0093] FIG. 7 shows an example of a pretreatment process for preparing waste plastics for catalytic upgrading. The plastic mixture is introduced into an optional pre-sorting system 20, which removes undesirable materials, rejects them in stream 22, and passes useful materials 21 to a washing process 30. The undesirable materials 22 can include items that are not easily processed with the waste plastics (e.g., metal, concrete, dirt, wood, minerals, glass, or other materials). In the washing step 30, a solvent, water, or aqueous solution 13 is mixed with the solid waste plastics, optionally agitated, and optionally heated, and the washed solids 31 are separated from the waste washing solution 32 and passed to a drying unit 40. At least a portion of the waste washing solution can be recycled to the washing unit 30. In the dryer 40, moisture and volatile solvents 42 are removed by exposure to a flowing gas stream (optionally heated). The dried material 41 is passed to a sizing unit 50. In the sizing unit, the plastic is shredded using any of a variety of cutting devices; large particles that do not pass through the sizing screen 52 are discarded or recycled to the pre-sorting system 20; and the sized material 51 is passed to an optional chemical pretreatment unit 60. In the chemical pretreatment unit, the material is heated to melt at least a portion of the plastic and drive off volatile off-gas products 63, such as HCl, HBr, HI, NH, CO, or other volatile decomposition products, to produce a pretreated material stream 61, which can be cooled and shredded to a suitable size for use in catalytic pyrolysis, or kept at an elevated temperature and fed directly to the catalytic pyrolysis process. As part of the chemical pretreatment unit 60, the molten mixture can be passed through a screen to remove solids or fragments 62 of material that do not melt under process conditions. The chemical pretreatment unit 60 can include one or more static mixers, which can pass the molten mixture through static mixing devices to enhance the homogeneity of the mixture.

[0094] The various units of the pretreatment process, i.e., 20, 30, 40, 50, and 60, can be rearranged depending on the needs of the particular waste plastic mixture, catalytic pyrolysis process, or other process, or existing infrastructure, and can include any combination of these elements, or other elements as needed. In some cases, not all of these units are required, and some can be omitted. In the schematic diagram of FIG. 7, pre-sorting unit 20 prepares the plastic mixture for further pre-processing, for example, by removing undesirable feed materials 22 (e.g., metals, minerals, halogenated materials, concrete, dirt, wood, glass, etc.). Sorting is often performed manually or by any of a number of automated processes, including items such as screens and pickers, which are well known in the art.

[0095] The cleaning step 30 involves introducing a solvent into the mixture under conditions of pressure and temperature, optionally at a flow rate, to loosen and remove adherent material (e.g., dirt, labels, food, organic waste, biomass, feces, dust, or other materials containing contaminants or that interfere with further pretreatment or processing steps). The solvent 13 can include water, an aqueous solution, an acidic solution, a basic solution, an organic solvent, or a mixed solvent, or some combination thereof, to enable removal of undesirable components. Cleaning can be performed at ambient temperature, or the solvent can be heated to 15°C to 100°C. In some embodiments, cleaning can include treatment with superheated water or steam or other vapors at least 100°C. Cleaning can be a single step or repeated, and different washes can use different solvents or process conditions. Any waste solvent(s) 32 are separated and can be discarded or processed for reuse in the cleaning process. The cleaning step can include a rinse step in which the material is treated with water or another solvent to remove the cleaning solution.

[0096] The washed material can be dried in a dryer. The drying step is typically operated at temperatures between 20°C and 150°C and can be augmented by a flow of gas (air or N2 or other inert gas mixtures). The dried plastic material contains no more than 20, 10, 5, 2, or 1% moisture by weight.

[0097] The washed and dried plastic material can be sized to a desired particle size in a sizing step 50. In the sizing unit, the plastic is sized by any one of a series of cutting devices, and large particles that do not pass through the sizing screen 52 can be discarded or recycled to the sorting system. Particles can be sized to be less than 25 cm (10 inches), less than 15 cm (6 inches), less than 10 cm (4 inches), less than 5 cm (2 inches), less than 2.5 cm (1 inch), less than 1.5 cm (0.6 inches), or less than 0.75 cm (0.3 inches), or to have a longest dimension between 0.2 and 25 cm, 0.75 and 10 cm, or 1.5 and 5 cm, or to pass through a 5 cm (2 inch), 2.5 cm (1 inch), 1.25 cm (0.5 inch), or 0.635 cm (0.25 inch) screen.

[0098] An optional sorting step can be performed after the sizing step 50. The optional sorting process can include any of a variety of sorting processes, such as automated sorting using optical, near-IR, ultraviolet, visible, or other recognition to identify components for removal, and can use automated removal, sedimentation / flotation, air leaching, foam flotation, etc., as are known in the art to remove unwanted materials.

[0099] The plastic feed mixture can be mixed to achieve a more homogeneous mixture by passing the molten mixture through one or more static mixing devices. The static mixing devices divide the flow, divert the flow, or do both to induce mixing of the materials. A typical static mixer comprises packings in the pipe shaped to divide and divert the molten flow passing through, or non-linear sections of pipe to induce mixing. A typical static mixer is shown in Figure 8 and is commercially available from a number of vendors. The static mixing device can operate at any temperature at which the plastic mixture will melt, for example, at least 80, 100, 150, 200, 225, or 250°C, or 80-350, 150-350, 150-300, or 200-250°C.

[0100] In particular, in the process shown in Figure 6, where pre-processing occurs at multiple facilities in a distributed network and the upgrading process occurs at a central facility, the pre-processing process can include an additional pelletization or other particle-forming process step to produce waste plastic particles into easier-to-handle cylindrical or near-spherical shapes. The pelletization process can involve feeding the waste plastic material into an extruder, such as stream 61 in Figure 7, where the material is heated to form a molten mixture that passes through an orifice. The resulting extrudate can be cooled, chopped or sliced ​​to a desired size for transportation and handling, and fed to a pyrolysis upgrading process, such as stream 111. An alternative pelletization process can involve stamping pellets from the solidified mixed plastics.

[0101] When recycled polymeric materials are used, impurities can optionally be removed from the feed composition before being fed to the reactor (e.g., by an optional separation step, such as 100 in FIG. 7). In some cases, the separation step can include mechanical separation, sink-float separation, air sieving, or other known separation processes, preferably in an automated mode. In some cases, the particle size of the solid polymeric feed composition can be reduced in a size reduction system, as part of 100, before passing the feed to the thermal treatment or pyrolysis reactor. In some embodiments, the mean diameter of the size-reduced feed composition exiting the size reduction system can include about 50% or less, about 25% or less, about 10% or less, about 5% or less, or about 2% or less of the mass mean diameter of the feed composition fed to the size reduction system. The feed mixture can include a plastic mixture in which at least 85%, or at least 90%, or at least 95% by weight of the particles pass through a 0.25 inch (0.6 cm), or 0.5 inch (1.2 cm), or 1.0 inch (2.5 cm), or 1.5 inch (3.7 cm), or 2 inch (5.0 cm), or 4 inch (10.0 cm) screen. The average diameter (size) can be determined by sieving through a mesh (screen). Large particle feed materials can be easier to transport and less difficult to process than small particle feed materials. However, in some cases it may be advantageous to feed small particles to the reactor. A size reduction system can be used to transport large particle feed between the source and the process while allowing small particles to be fed to the reactor.

[0102] Examples 1 to 10 A drip-tube reactor for the two-step chemical conversion of plastics without separation between the pyrolysis and catalytic pyrolysis steps was constructed using a quartz reactor tube (ACE Glass) containing a fused quartz frit (40–90 μm) in its center. Figure 4 shows the configuration of the drip-tube reactor. A sample cell (10 mm outer diameter, 8 mm inner diameter, 25 mm length, quartz, manufactured by TGP) was used to insert the feedstock using two pieces of quartz wool (TGP). As shown in Figure 4, the sample cell was placed in a reactor cap (borosilicate, ACE Glass) and held in place by a stopper (1 / 4 inch (6 mm) aluminum rod, McMaster). The reactor cap and quartz reactor were then assembled and installed into a fixed-bed reactor system. The bottom of the reactor was connected to a condenser (borosilicate) packed with a porous stainless steel packing (ACE Glass) immersed in an ice-water bath (0 °C). A heating mantle was applied between the bottom of the reactor and the top of the condenser to prevent any condensation before the condenser. The heating mantle was set at 210° C. during the reaction.

[0103] In the reactor, a small sample (1.5 g) of ZSM-5 catalyst was placed on a quartz frit. The feedstock (100 mg for each run) in the sample cell was sealed with quartz wool. The catalyst / feedstock weight ratio was approximately 15. Before the contents of the sample cell were dropped into the reactor, the catalyst was calcined at 550 °C for 20 min under an air flow of 100 mL / min (heating rate = 12 °C / min). After calcination, the reactor was cooled to the reaction temperature (500 °C). During cooling, the condenser was filled with 10 mL of solvent (ethyl acetate for plastic conversion, acetone for biomass conversion) and held for 10 min for temperature lineout. The reactor system was then purged with a helium flow of 75 mL / min for 20 min to remove air and purge the gas collection lines. The sample cell containing the feedstock was dropped into the reactor by withdrawing the stopper rod, and the reaction was initiated.

[0104] A 10 minute hold period allowed the reaction to reach completion. The gas products, consisting mostly of permanent gases and C1-C3 olefins and paraffins, were collected in a gas bag. The liquid products (mostly C 4+) was collected in the condenser. After the reaction, the temperature was increased to 650 °C without gas flow. The solid products, including coke and charcoal, remaining in the reactor were then combusted at 650 °C for 10 min under an air flow of 50 mL / min. The gas products during combustion were collected in a second gas bag. An additional 3 mL of solvent was added to the condenser to extract any products remaining on top of the condenser. The entire liquid in the condenser was then transferred to a 20 mL sample vial. A weighed amount of internal standard (dioxane, typically 3000–5000 mg, Sigma-Aldrich) was added to the sample vial. The condenser was washed with acetone and dried in a drying oven. Note that a small amount of liquid remained in the condenser due to holdup in the packing. Therefore, the condenser with and without the liquid product was weighed to determine the total amount of liquid product. Liquid samples were analyzed for hydrocarbons and oxygenates by GC-FID (Gas Chromatograph with a Shimadzu 2010Plus Flame Ionization Detector). Gas bag samples were analyzed using an Agilent GC 7890B Gas Chromatograph.

[0105] The results of experiments with various feeds are shown in Table 2. The remainder of the products not accounted for in Table 2 includes water, inert solids, and minor components that are not easily recovered for combustion.

[0106] Examples 1-10 demonstrate the production of high yields of olefins and aromatics from plastics by two-step pyrolysis followed by catalytic pyrolysis without an intervening separation step. Olefin yields are at least 2% in all cases, and BTX yields are at least 10.08% in all cases. Examples 1, 2, 3, 4, and 9 demonstrate that for unfilled polymers (tires) or heteroatom-free polymers (PET, nylon), BTX yields are at least 32.88%, olefin yields are at least 5.58%, and coke and char yields are less than 5%, and often less than 2%, by weight of the feed. In two-step pyrolysis / catalysis of polyolefins, olefin yields (Examples 1, 2, 3, and 4) are at least 10.43%, and linear, unbranched polyolefin yields (Examples 1, 2, and 3) are at least 17.25%. The aromatics yield in the two-step pyrolysis / catalysis of polyolefins (Examples 1, 2, 3, and 4) is at least 32.88%, and the linear unbranched polyolefin yield (Examples 1, 2, and 3) is at least 45.6%. [Table 2]

Claims

1. 1. A system or method for upgrading waste plastics into useful products, comprising: a plurality of plastic pre-treatment facilities; a. each pre-treatment facility forms one spoke of a "hub and spoke" network; b. pretreatment at each pretreatment facility includes increasing the temperature of the waste plastic to at least 100°C; c. i. the hub comprises a catalytic pyrolysis unit, or ii. each spoke comprises a catalytic pyrolysis unit; The system or method wherein at least a portion of the products of each spoke is collected and processed at a central processing facility (the hub) for upgrading, separation, and purification into product streams.

2. 10. The system or method of claim 1, wherein the pre-treatment comprises one or more of the following, in any order: collecting, separating, sorting, mixing, removing contaminants, heat treating, sanitizing, decontaminating, sterilizing, dechlorinating, washing, drying, sizing, melting, filtering, pelletizing, or combinations thereof.

3. 10. The system or method of claim 1, wherein the products of the catalytic pyrolysis comprise one or more of benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6 to C20 paraffins and olefins, ethylene, propylene, or naphthalene, hydrogen, or any combination thereof.

4. 3. The system or method of claim 2, wherein the pre-treatment comprises a thermal treatment comprising two or more thermal treatment reactors.

5. 3. The system or method of claim 2, wherein the pre-processing facility further comprises a shredder, a granulator, a de-packaging unit, a de-watering unit, or any combination thereof.

6. 5. The system or method of claim 4, wherein each thermal treatment reactor comprises one or more of a moving bed, single screw extruder, twin screw extruder, multi-screw extruder, planetary extruder, ultrasonically assisted extruder, auger reactor, rotary kiln reactor, stirred tank reactor, or stepped grate reactor, or any combination thereof.

7. 5. The system or method of claim 4, wherein the material is heated to a temperature of 180°C to 300°C in a first heat treatment reactor and the condensed product is passed to a second heat treatment reactor.

8. A sweep gas is fed to the heat treatment reactor and comprises HCl, HBr, HI, NH ３ , CO ２ , N ２ , H ２ O, Air, Ar, or CH ４ The system or method of claim 1 , wherein the vapor stream comprising at least one of:

9. 10. The system or method of any preceding claim, wherein one of the thermal processing reactors comprises an inlet port and an outlet port, wherein the temperature at or near the inlet port can be 20-225°C (e.g., 20-100°C or 20-50°C), and the temperature range of the hot outlet port can be 300-700°C (e.g., 325-650°C, 350-600°C, or 350-575°C).

10. 5. The system or method of claim 4, wherein the residence time of the condensed phase in the thermal treatment reactor(s) is at least 0.5 minutes, 5 minutes, 10 minutes, 20 minutes, or at least 30 minutes, or from 1 to 60 minutes, from 5 to 30 minutes, from 10 to 30 minutes, or from 0.5 to 10 minutes.

11. 5. The system or method of claim 4, wherein the heat treatment reactor comprises one or more single screw or twin screw extruders and stirred tank reactors.

12. 10. The system or method of any preceding claim, wherein the filtering is accomplished by first heating the plastic mixture to at least 200°C in a heat treatment reactor to reach a molten state and filtering to remove solids.

13. 3. The system or method of claim 2, wherein the pre-treatment comprises passing the molten plastic to a static mixer.

14. 10. The system or method of any preceding claim, wherein the contaminants are removed by anaerobically heating the feed mixture in a thermal treatment reactor to a temperature of 150°C to 350°C or 250°C to 300°C to at least partially decompose the polymer.

15. 5. The system or method of claim 4, wherein the feed is heated to a temperature of 250-300°C in a first heat treatment reactor and the product from the first heat treatment reactor is passed to a second heat treatment reactor.

16. 10. A system or method according to any preceding claim, wherein a solid co-reactant is fed to the thermal processing reactor.

17. 17. The system or method of claim 16, wherein the solid co-reactant material comprises one or more materials selected from agricultural lime, calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, limestone, hydrotalcite, activated carbon, or zeolite, or other solid basic material, or any combination thereof.

18. 17. The system or method of claim 16, wherein the solid co-reactant is withdrawn from the thermal treatment reactor and transferred to a combustion regenerator, where carbonaceous material reacts with air, and at least a portion of the hot solid co-reactant is returned to the thermal treatment reactor.

19. 10. A system or method according to any preceding claim, wherein the products produced in the pretreatment process are transferred to a catalytic pyrolysis reactor containing a catalyst without separation of the majority of the products.

20. 10. A system or method according to any preceding claim, wherein the molten product of the pre-treatment is fed to a pelletizing process and cut into pellets.

21. 10. The system or method of claim 1, wherein the feed to the catalytic pyrolysis reactor comprises pellets.

22. 3. The system or method of claim 2, wherein a pre-sorting unit prepares the plastic mixture for further pre-processing by removing undesirable feed materials including, for example, metals, minerals, halogenated materials, concrete, dirt, wood, glass, or combinations thereof.

23. 3. The system or method of claim 2, wherein the cleaning comprises treatment with superheated water or steam or other vapors at a temperature of at least 100°C.

24. 3. The system or method of claim 2, wherein the washing is accomplished by mixing water, an aqueous solution, an acidic solution, a basic solution, an organic solvent, or a mixed solvent, or any combination thereof, with the solid waste plastic, and the washed solids are separated from the waste washing solution.

25. 25. The system or method of claim 24, wherein the washing is repeated, the second washing using a different solvent.

26. 26. The system or method of claim 23, 24, or 25, wherein the cleaning includes a rinsing step in which the material is treated with water or another solvent to remove the cleaning solution.

27. 3. The system or method of claim 2, wherein the plastic is dried by removing moisture and volatile solvents from the plastic by exposure to a flowing gas stream (optionally heated at a temperature between 20°C and 150°C).

28. 3. The system or method of claim 2, wherein the plastic is sized by a cutting device and large particles that do not pass through a sizing screen are discarded or recycled to the pre-sorting system.

29. 29. The system or method of claim 28, wherein the plastic particles are sized to have a longest dimension of less than 25 cm (10 inches), less than 15 cm (6 inches), less than 10 cm (4 inches), less than 5 cm (2 inches), less than 2.5 cm (1 inch), less than 1.5 cm (0.6 inches), or less than 0.75 cm (0.3 inches), or between 0.2 and 25 cm, 0.75 and 10 cm, or 1.5 and 5 cm, or to pass through a 5 cm (2 inch), 2.5 cm (1 inch), 1.25 cm (0.5 inch), or 0.635 cm (0.25 inch) screen.

30. 10. The system or method of claim 1, wherein the pre-processing includes sorting the sizing material accomplished using optical, near-IR, ultraviolet, visible, or other recognition to identify components for removal, and wherein automated removal, sedimentation / flotation, air leaching, or foam flotation is used to remove unwanted material.

31. 3. The system or method of claim 2, wherein the pre-treatment process includes a pelletizing or other particle forming process step to produce cylindrical or spherical waste plastic particles.

32. 32. The system or method of claim 31, wherein the pelletizing process includes feeding waste plastic material into an extruder where the material is heated to form a molten mixture that is forced through an orifice, cooled, and chopped or sliced ​​to a desired size for transport to a catalytic pyrolysis upgrading facility.

33. 33. The system or method of claim 32, wherein the particle forming process comprises stamping pellets from a solidified plastic mixture.

34. The waste plastics may be polyethylene, polypropylene, polyester, polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene (ABS) copolymer, polyamide, polyurethane, polyether, polycarbonate, poly(oxide), poly(sulfide), polyarylate, polyether ketone, polyetherimide, polysulfone, polyurethane, polyvinyl alcohol, and polymers produced by polymerization of monomers, such as dienes, olefins, styrene, acrylates, acrylonitrile, methacrylates, methacrylonitrile, diacids and diols, lanthanides, methyl methacrylates ...

3. The system or method of any preceding claim, comprising a plastic selected from lactones, diacids and diamines, lactams, vinyl esters, block copolymers thereof, and alloys thereof; thermosetting polymers such as epoxy resins; phenolic resins; melamine resins; alkyd resins; vinyl ester resins; unsaturated polyester resins; crosslinked polyurethanes; polyisocyanurates; crosslinked elastomers (including, but not limited to, polyisoprene, polybutadiene, styrene-butadiene, styrene-isoprene, ethylene-propylene-diene monomer polymers); and mixtures thereof.

35. 10. A system or method according to any preceding claim, wherein the waste plastic comprises a mixture of waste plastics selected from polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC) or polyvinylidene chloride (PVCD), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or mixed resins, or any combination thereof.

36. 10. A system or method according to any preceding claim, wherein the catalytic reactor is a fluidized bed, circulating bed, bubbling bed or riser reactor, contains a catalyst and operates at a temperature in the range of 300°C to 800°C, 350°C to 750°C, 400°C to 700°C, 450°C to 650°C, 500°C to 600°C, or 525°C to 575°C.

37. 2. The system or method of claim 1, wherein the pressure in the catalytic pyrolysis reactor is at least 0.1 MPa (1 bar), at least 0.3 MPa (3 bar), or at least 0.4 MPa (4 bar), or from 0.1 to 2.0 MPa (1 to 20 bar), from 0.1 to 1.0 MPa (1 to 10 bar), or from 0.3 to 0.8 MPa (3 to 8 bar), preferably from 0.4 to 0.6 MPa (4 to 6 bar).

38. The fluidizing gas for the catalytic pyrolysis is H ２ , CO, CO ２ , H ２ O, C1-C4 paraffins or olefins or both, N ２ , Ar, He, other inert gases, or recycle streams, or any combination thereof.

39. 37. The system or method of claim 36, wherein the residence time of the fluidizing gas in the catalytic pyrolysis reactor (defined as the reactor volume divided by the volumetric flow rate of the fluidizing fluid under process conditions of temperature and pressure) can be from 1 second to 480 seconds, or from 1 second to 240 seconds, or from 2 seconds to 60 seconds, or from 3 seconds to 30 seconds, or from 4 seconds to 15 seconds.

40. 37. The system or method of claim 36, wherein the catalyst comprises a zeolite.

41. 37. The system or method of claim 36, wherein the catalyst can be selected from natural zeolites, synthetic zeolites, or combinations thereof, or ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-50, or combinations thereof.

42. 4. The system or method of claim 3, wherein the product vapor mixture from the catalytic conversion comprises at least 20% by weight olefins, or at least 50% by weight olefins, or in the range of 20 to 90% by weight olefins.

43. 4. The system or method of claim 3, wherein the mass yield of BTX in the gaseous product mixture from the catalytic conversion is at least 10%, 20%, 30%, 40%, 50%, or at least 60%, or 10% to 90%, or 20% to 70%, or 30% to 60% BTX based on the mass in the polymer feed.

44. 4. The system or method of claim 3, wherein the vapor products of the catalytic pyrolysis are passed through one or more solids separation devices comprising cyclones.

45. 4. The system or method of claim 3, wherein the catalyst in the catalytic pyrolysis reactor is withdrawn, regenerated by oxidation with air, and returned to the catalytic pyrolysis reactor.

46. 46. ​​The system or method of claim 45, wherein heat from the regeneration of the catalyst provides energy for a thermal treatment or catalytic pyrolysis step.

47. 46. ​​The system or method of claim 45, wherein at least a portion of the gases in the product mixture are combusted in the regenerator.

48. the gaseous catalytic pyrolysis product mixture is CH ４ , CO, and H ２ is subjected to a separation process to produce a concentrated gas stream, ４ , CO, and H ２ 46. ​​The system or method of claim 45, wherein at least a portion of the gas stream enriched with is passed to the regenerator where it is combusted.

49. 4. The system or method of claim 3, wherein non-vapor products of the catalytic pyrolysis reactor, or a portion of the gas remaining after removal of desired products, or both, are combusted to provide energy for the pyrolysis or catalytic pyrolysis process.

50. 4. The system or method of claim 3, wherein a portion of the vapor product from the catalytic pyrolysis process is fed to a condenser where it is cooled to produce a condensed material.

51. 51. The system or method of claim 50, wherein the condensed material is separated into fractions by distillation and at least a portion of the paraffins, olefins, or aromatics containing more than 7 carbon atoms, or combinations thereof, or fractions boiling above 300°C or boiling in the range of 300°C to 800°C, are recycled to the thermal treatment or catalytic pyrolysis reactor.

52. 10. A system or method according to any preceding claim, wherein at least 2, or at least 3, or at least 5, or at least 7, or at least 10, or at least 15, or 2 to 20, or 3 to 10, or 5 to 10 plastics pre-treatment facilities feed one catalytic pyrolysis and product separation and purification facility.

53. 10. A system or method according to any preceding claim, wherein at least 2, or at least 3, or at least 5, or at least 7, or at least 10, or at least 15, or from 2 to 20, or from 3 to 10, or from 5 to 10 pretreatment and catalytic pyrolysis units feed one separation and purification facility.

54. 10. The system or method of any preceding claim, wherein the total pretreated product mixture prepared in the at least two plastics pretreatment facilities that is introduced into a central catalyst upgrading, separation, and refining facility is at least 20, or at least 50, or at least 100, or at least 150, or at least 200 metric tons per day, or from 20 to 500, or from 30 to 200, or from 50 to 150 metric tons per day.

55. 10. The system or method of any preceding claim, wherein the total crude product mixture prepared in the at least two plastics pretreatment and catalyst upgrading facilities introduced into a central separation and refining facility is at least 20, or at least 50, or at least 100, or at least 150, or at least 200 metric tons per day, or from 20 to 500, or from 30 to 200, or from 50 to 150 metric tons per day.

56. 10. A system or method according to any preceding claim, wherein the central facility for separation and purification is at a refinery or chemical production facility.

57. 10. The system or method of any preceding claim, wherein benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6-C20 paraffins and olefins, ethylene, propylene, or naphthalene, or others, or any combination thereof, prepared from pre-treated waste plastics at multiple facilities, is separated and purified at a central separation and purification facility.

58. A distributed system for converting waste plastics, polymers, and other waste materials into useful chemical and fuel products (e.g., paraffins, olefins, and aromatics (e.g., BTX)) in a thermochemical process, the method comprising pre-treating the feed mixture at a temperature of at least 100°C prior to a catalytic pyrolysis process.

59. 1. A method for producing chemicals, fuels, or both, comprising: a. providing waste plastic to a first processing site, said first processing site configured to receive waste plastic; b. pre-treating the waste plastic at the first processing site at a temperature of at least 100°C and transferring the pre-treated waste plastic to one or more transfer carriers; c. transporting the one or more mobile carriers to a second processing site, the second processing site configured to receive pre-processed waste plastic from at least one additional plastic source; d. Removing the pre-treated waste plastic from the one or more transfer carriers transported in step (c); e. producing chemicals, fuels, or both using plastics from the pretreated waste plastic removed in at least step (d) and plastics from at least one other plastic source.

60. The feed mixture at the first processing site may be composed of polyethylene, polypropylene, polyester, polyethylene terephthalate (PET), acrylonitrile-butadiene-styrene (ABS) copolymer, polyamide, polyurethane, polyether, polycarbonate, poly(oxide), poly(sulfide), polyarylate, polyether ketone, polyetherimide, polysulfone, polyurethane, polyvinyl alcohol, and polymers produced by polymerization of monomers such as dienes, olefins, styrene, acrylates, acrylonitrile, methacrylates, and methacrylonitrile.

60. The method of claim 59, wherein the polymer comprises a plastic selected from the group consisting of diacids and diols, lactones, diacids and diamines, lactams, vinyl esters, block copolymers thereof, and alloys thereof; thermosetting polymers such as epoxy resins; phenolic resins; melamine resins; alkyd resins; vinyl ester resins; unsaturated polyester resins; crosslinked polyurethanes; polyisocyanurates; crosslinked elastomers (including, but not limited to, polyisoprene, polybutadiene, styrene-butadiene, styrene-isoprene, ethylene-propylene-diene monomer polymers); and mixtures thereof.

61. 60. The method of claim 59, wherein the feedstock comprises a mixture of waste plastics selected from polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC) or polyvinylidene chloride (PVCD), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or mixed resins, or any combination thereof.

62. 60. The method of claim 59, wherein the pre-treatment process may include one or more of collection, separation, sorting, blending, removal of contaminants, heat treatment, dechlorination, washing, drying, sizing, melting, filtering, pelletizing, or combinations thereof.

63. 60. The method of claim 59, wherein the pretreatment process steps can be performed in any order.

64. 60. The method of claim 59, wherein the plastic mixture is filtered by first heating to at least 80°C in a heat treatment reactor to achieve a molten state and filtering to remove solids.

65. 60. The method of claim 59, wherein the residence time of the condensed phase in the heat treatment reactor, or in any of the heat treatment reactors if there is more than one, is at least 1 minute, or at least 5 minutes, or at least 10 minutes, or at least 20 minutes, or at least 30 minutes, or from 1 to 60 minutes, or from 5 to 30 minutes, or from 10 to 30 minutes.

66. 60. The method of claim 59, wherein benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6 to C20 paraffins and olefins, ethylene, propylene, or naphthalene, or others, or any combination thereof, prepared from pre-treated waste plastics at multiple facilities is separated and purified at a central separation and purification facility.

67. 67. A method of producing benzene, toluene, xylene, p-xylene, m-xylene, o-xylene, BTX (a mixture of benzene, toluene, and xylene), C6-C20 paraffins and olefins, ethylene, propylene, naphthalene, hydrogen, or others prepared from waste plastics, or any combination thereof, using any of the systems or methods of claims 1-66.

68. 10. The system or method of claim 1, wherein the central processing facility (the hub) further comprises a catalytic upgrading unit that converts the products collected from each spoke into higher value chemicals, fuels, or both.

69. 10. The system or method of claim 1, wherein the central processing facility (the hub) further comprises a refinery unit that separates and refines the upgraded product into individual chemical and fuel streams.

70. 10. The system or method of claim 1, wherein the waste plastic is collected from residential, commercial, industrial, or municipal waste, or any combination thereof.

71. 10. The system or method of claim 1, wherein the central processing facility (the hub) is integrated into an existing petrochemical or refining complex.

72. 10. The system or method of claim 1, wherein the central processing facility (the hub) is located within one mile of a waste plastic collection facility.

73. 10. The system or method of claim 1, wherein the central processing facility (the hub) utilizes renewable energy including solar, wind, nuclear, renewable diesel, renewable gasoline, renewable jet fuel, renewable natural gas, renewable syngas, or any combination thereof to power the pretreatment, catalytic pyrolysis, or the upgrading process.

74. 10. The system or method of claim 1, wherein the central processing facility (the hub) further comprises a carbon capture and utilization system for sequestering carbon dioxide emissions and optionally using the captured carbon to generate chemical products.

75. 10. The system or method of claim 1, wherein said central processing facility (the hub) further comprises a cogeneration system that produces both electricity and heat from the waste plastic conversion process.

76. 10. The system or method of claim 1, wherein either the central processing facility (the hub) or the pre-processing facility is a portable modular system.

77. 10. The system or method of claim 1, further comprising a central database or control center that receives and processes real-time data from each pretreatment facility, the catalytic pyrolysis reactor, and other associated components, and wherein the central database or control center coordinates and optimizes the operation of the distributed system.

78. 10. The system or method of claim 1, wherein transportation of pre-treated waste plastic from each pre-treatment facility to the central processing facility or the catalytic pyrolysis reactor is facilitated through an intelligent logistics system, which autonomously schedules and dispatches transportation vehicles or devices based on the real-time capacity and demand of each facility.

79. 10. A system or method according to any preceding claim, wherein the hub comprises a catalytic pyrolysis unit.

80. A system or method according to any preceding claim, wherein each spoke comprises a catalytic pyrolysis unit.

81. 1. A process for producing olefins and aromatics, comprising: feeding a plastics-containing stream to a first pyrolysis reactor; anaerobically pyrolyzing the stream in the first pyrolysis reactor at a temperature greater than 350°C to produce a first product mixture; passing the first product mixture produced in the first pyrolysis reactor without separating a portion of the first product mixture to a second catalytic pyrolysis reactor comprising a fluidized bed equipped with a catalyst; catalytically reacting the first product mixture in the fluidized bed reactor to form a catalytic pyrolysis product mixture; recovering olefins, aromatics, or any combination thereof from the product mixture.

82. 82. The method of claim 81, wherein the first product stream produced in the first pyrolysis reactor is passed to a second reactor at a temperature greater than 350°C without cooling.

83. 10. The method of any of the preceding claims, wherein the first pyrolysis reactor is a moving bed, a single screw extruder, a twin screw extruder, an auger reactor, a rotary kiln reactor, or a stepped grate reactor.

84. 10. The method of any preceding claim, wherein the first pyrolysis reactor comprises a feed inlet port and an outlet port, and the temperature within the pyrolysis reactor ranges from a lower temperature near the feed inlet port to a higher temperature at the outlet port.

85. 10. The method of claim 1, wherein the temperature in the first pyrolysis reactor may be from 20°C to 225°C (e.g., 20-100°C or 20-50°C) at or near the inlet port, and the temperature range at the outlet port may be from 300°C to 700°C (e.g., 325-650°C, 350-600°C, or 350°C to 575°C).

86. 10. A method according to any preceding claim, wherein the feed stream is treated in a thermal treatment reactor, for example at a temperature of 250-300°C, and the condensed phase is passed to said first pyrolysis reactor.

87. 10. The method of any preceding claim, wherein the first pyrolysis reactor comprises two or more reactors in a series configuration.

88. 10. The method of any of the preceding claims, wherein an inert gas is fed to the heat treatment reactor and the steam is vented.

89. 10. The method of any preceding claim, wherein the residence time of the condensed phase in the thermal treatment or first pyrolysis reactor(s) is at least 1, at least 5, at least 10, at least 20, or at least 30 minutes, or from 1 to 60, from 5 to 30, or from 10 to 30 minutes.

90. 10. The method of any of the preceding claims, wherein a solid co-reactant is fed to the heat treatment reactor.

91. 91. The method of claim 90, wherein the solid co-reactant is transferred to a combustion regenerator where a carbonaceous material reacts with air, and at least a portion of the hot solid co-reactant is returned to the thermal treatment reactor.

92. 92. The method of claim 91, wherein hot flue gas exiting the solid co-reactant regenerator is passed to a catalytic heater to heat the catalyst in the catalytic pyrolysis reactor.

93. 10. The method of any preceding claim, wherein the catalyst in the fluidized bed reactor comprises a zeolite.

94. 94. The method of claim 93, wherein the catalyst has a SAR (silica to alumina, SiO2:Al2O3 mass ratio) of greater than 12 or from 12 to 240, and a CI (constraint index) of 1 to 12 or from 5 to 10.

95. 94. The method of claim 93, wherein the zeolite catalyst is selected from among ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-50, or a combination thereof.

96. 94. The method of claim 93, wherein the catalyst comprises ZSM-5.

97. 10. The method of any preceding claim, wherein the catalyst in the fluidized bed comprises a binder material selected from alumina, zirconia, silica, magnesia, thoria, titania, boria, or combinations thereof.

98. 10. The method of any preceding claim, wherein the catalyst in the fluidized bed comprises a catalytic molecular sieve, the catalytic molecular sieve comprising 30 to 90 weight percent or 40 to 70 weight percent of the composition of the particles of the catalyst.

99. The catalyst in the fluidized bed 10. A method according to any preceding claim, in the form of flowable microspheres.

100. 10. The method of any preceding claim, wherein the hot product stream from the thermal treatment reactor is filtered to remove solids before being fed to the first pyrolysis reactor.

101. 10. The method of any preceding claim, wherein non-vapor products of the thermal treatment reactor, or a portion of the gas remaining after removing desired products, or both, are combusted to provide energy for the catalytic reaction in the fluidized bed.

102. 10. The method of any preceding claim, wherein the product vapor mixture from the fluidized bed catalytic reactor comprises at least 20% by weight BTX, and in some embodiments in the range of 20 to 90% by weight BTX.

103. 11. The method of claim 10, wherein the solid co-reactant fed to the heat treatment reactor comprises agricultural lime, or calcium oxide, calcium hydroxide, magnesium oxide, magnesium hydroxide, limestone, hydrotalcite, activated carbon, or zeolite, or other solid basic material, or any combination thereof.

104. 10. The method of any preceding claim, wherein the catalytic pyrolysis product is passed through one or more solids separation devices.

105. 105. The method of claim 104, wherein the solids separation device(s) comprise one or more cyclones.

106. 10. A method according to any preceding claim, wherein the catalyst in the fluidized bed catalytic pyrolysis reactor is withdrawn, regenerated by oxidation with air and returned to the catalytic pyrolysis reactor.

107. 107. The method of claim 106, wherein heat recovered from the catalyst regenerator is used to heat the feedstock, the first pyrolysis reactor, or catalytic pyrolysis in the fluidized bed reactor, or any combination thereof.

108. 10. The method of any preceding claim, wherein the temperature of the fluidized bed catalytic reactor is in the range of 300°C to 800°C, 350°C to 750°C, 400°C to 700°C, 450°C to 650°C, 500°C to 600°C, or 525°C to 575°C.

109. 10. The method of any preceding claim, wherein the residence time of the fluidizing gas in the catalytic pyrolysis reactor is from 1 second to 480 seconds, or from 1 second to 240 seconds, or from 2 seconds to 60 seconds, or from 3 seconds to 30 seconds, or from 4 seconds to 15 seconds.

110. 10. The method of any preceding claim, wherein the product mixture from the fluidized bed catalytic reactor comprises at least 20% by weight of olefins, in some embodiments in the range of 20 to 90% by weight of olefins.

111. 10. The method of any preceding claim, wherein the product mixture from the fluidized bed catalytic reactor comprises at least 30%, at least 40%, at least 45%, at least 50%, at least 55%, or at least 60%, or 20% to 90%, 30% to 70%, or 45% to 60% olefins based on the mass in the polymer feed.

112. 10. The method of any preceding claim, wherein the mass yield of BTX in the product vapor mixture from catalytic conversion is at least 30%, at least 40%, at least 45%, at least 50%, at least 55%, or at least 60%, or 20% to 90%, 30% to 70%, or 45% to 60% BTX based on the mass in the polymer feed.

113. 10. The method of any preceding claim, wherein benzene, toluene, or xylenes are separated or recovered from the catalytic pyrolysis product mixture.

114. 10. The method of any preceding claim, wherein at least a portion of the aromatic products in the catalytic pyrolysis product mixture are hydrogenated to produce naphthenes.

115. 10. The method of any preceding claim, wherein ethylene, propylene, or butenes are separated from the catalytic pyrolysis product mixture.

116. The product vapor mixture is CH ４ , CO, and H ２ is subjected to a separation process to produce a concentrated gas stream, ４ , CO, and H ２ 10. A method according to any preceding claim, wherein at least a portion of the gas stream enriched with is passed to the regenerator where it is combusted.

117. The catalytic pyrolysis product mixture is CH ４ and C2 to C4 paraffins, ４ and 50 to 100 mass % of the C2 to C4 paraffins are combusted in the regenerator.

118. 10. A method according to any preceding claim, wherein the thermal treatment is carried out by heating the feed to a temperature of 250-300°C, holding that temperature while steam is removed, and then further pyrolyzing the condensed phase at a higher temperature in the first pyrolysis reactor.

119. 10. The method of any preceding claim, wherein the feedstock comprises a mixture of waste plastics selected from polyethylene terephthalate (PET), high density polyethylene (HDPE), polyvinyl chloride (PVC) or polyvinylidene chloride (PVCD), low density polyethylene (LDPE), polypropylene (PP), polystyrene (PS), or mixed resins, or any combination thereof.

120. 10. A method according to any preceding claim, wherein the pressure in the fluidized bed reactor is at least 0.1 MPa, at least 0.3 MPa, or at least 0.4 MPa, or from 0.1 to 2.0 MPa (1 to 20 bar), from 0.1 to 1.0 MPa, or from 0.3 to 0.8 MPa, preferably from 0.4 to 0.6 MPa.

121. 10. The method of claim 1 of any of the preceding claims, wherein a portion of the vapor product from the catalytic pyrolysis process is fed to a condenser where it is cooled to produce a condensed material, and a portion of the condensed material is recycled to the pyrolysis reactor.

122. 122. The method of claim 121, wherein a portion of the condensed material is separated into fractions and at least a portion of the condensed material is recycled to the pyrolysis reactor or the catalytic pyrolysis reactor.

123. 122. The method of claim 121, wherein the condensed material is separated into fractions by distillation and at least a portion of the paraffins, olefins, or aromatics, or combinations thereof, containing more than 7 carbon atoms are recycled to the pyrolysis or catalytic pyrolysis reactor.

124. 122. The method of claim 121, wherein the condensed material is separated into fractions by distillation and at least a portion of the fractions boiling above 300°C or boiling in the range of 300 to 800°C are recycled to the pyrolysis reactor or the catalytic pyrolysis reactor.

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