Catalytic pyrolysis of polymers to produce olefins and aromatics.

Abstract

The present invention includes a method for catalytically pyrolyzing plastics. Because it has been discovered that plastics provide insufficient coke to provide adequate heat during catalyst regeneration, a heat-forming additive can be introduced into the method. Systems and compositions useful for the catalytic pyrolysis of plastics are also described.

Description

[Technical Field]

[0001] Related Applications This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 847,933, filed May 14, 2019.

[0002] The present invention relates to the conversion of waste plastics, polymers and other waste materials, or biomass materials, into useful chemical and fuel products, such as paraffins, olefins and BTX, with minimal or no energy consumption from external sources.

[0003] preface In 2018, plastic production in the United States was 38.5 million tons, or 13.1 percent of MSW production. Over 350 million tons of plastic were generated worldwide. Plastic recycling involves recovering scrap or waste plastic and reprocessing the material into useful products. However, due to China's ban on waste plastic imports, the recycling rate in the United States is estimated to have dropped to 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, such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene terephthalate (PET), for separate recycling processes.

[0005] Bio-TCat™ is a catalytic pyrolysis technology that converts renewable biomass materials into a mixture of permanent gases, C2-C4 light olefins, C1-C4 light paraffins, C5+ hydrocarbons, C11+ hydrocarbons, including aromatics benzene, toluene, and xylenes ("BTX") and non-aromatic naphtha-range molecules, coke and char, and trace amounts of by-products. Conversion occurs in a fluidized-bed reactor using ZSM-5 zeolite or a similar catalyst. A portion of the light gases produced by the reaction can be recycled to the reactor to provide fluidization gas and to inject biomass feedstock into the vessel. Coke and char by-products, which accumulate on the catalyst and temporarily deactivate it, are removed by oxidation in a continuously operating catalyst regenerator. Waste materials that can be processed by Bio-TCat include biomass, waste tires, lubricating oil, coal, and petroleum residues.

[0006] A new technology is Plas-TCat™, which is also a catalytic fluidized bed process using a zeolite catalyst, but the feedstock is polymer / plastic materials, particularly waste plastics that might otherwise be sent to landfills or incinerators. Plastic mixtures that have a relatively high hydrogen-to-carbon molar ratio and exclude chlorine and nitrogen, such as polyethylene (PE), polypropylene, polystyrene, and combinations, can be converted to olefins and aromatics, but the process requires energy from external sources, such as fossil fuels, because combustion of the by-products may not produce the energy needed for the process.

[0007] US 5,158,983 teaches a process by which a mixture of waste plastics and scrap rubber tires can be directly converted into high-quality synthetic crude oil using an oil-soluble catalyst under high pressure of hydrogen. A small amount of coke is formed.

[0008] US 5,364,995 teaches a process for vaporizing plastics in the absence of a catalyst to produce light olefins, paraffins, naphthenes, olefin oligomers and waxes. Further upgrading of the product stream by steam cracking is disclosed.

[0009] US 8,895,790 describes a method for converting plastics into olefins and aromatics, in which the pyrolysis reaction is carried out above 550°C.

[0010] US 9,428,695 describes a process for converting a mixture of plastics into olefins and aromatics using a fluidized bed of FCC and ZSM-5 catalysts, which may require supplemental heat input from an external heat source.

[0011] World patent WO2017 / 103010 describes a method for converting plastics into products in a temperature range below 500°C.

[0012] It is an object of the present invention to provide for the conversion of waste plastics, polymers and other materials into useful chemical and fuel products such as paraffins, olefins and BTX with minimal or no energy consumption from external sources. Summary of the Invention

[0013] In a first aspect of the invention, a mixture comprising a polymer is converted in a fluidized bed catalytic pyrolysis process to produce olefins, aromatics, coke, gases and other by-products, and the energy produced from the combustion of the coke, or coke and other by-products, in a catalyst regenerator, or by other means, is at least equal to the energy required to operate the pyrolysis process.

[0014] In another aspect, the present invention is a method for converting plastics to olefins, comprising: feeding a polymer or a mixture of polymers to a reactor; pyrolyzing the material in the reactor in the presence of a catalyst under reaction conditions sufficient to produce a gaseous raw product mixture comprising one or more olefins.In some embodiments, the method is characterized in that: a plurality of olefins are produced and the olefins are separated from the gaseous raw product mixture for subsequent conversion in another process; the olefin conversion process comprises hydrogenation, hydrolysis, hydroformylation, cyclization, dimerization, polymerization, or alkylation; the olefin conversion process comprises one or any combination of the following steps: conversion of olefins to alcohols or ethers; low temperature (80°C to 400°C) polymerization of olefins; reaction with CO to form carboxylic acids or aldehydes; alkylation with aromatics to form alkylated aromatics, and hydrogenation to paraffins; the polymer or polymer mixture is melted and further comprises filtering solids from the molten mixture before pyrolysis; the pyrolysis step comprises fast solid pyrolysis in the presence of a catalyst; the catalyst comprises a zeolite; and the reaction is carried out in a fluidized bed, circulating bed, bubbling bed, or riser at an operating temperature ranging from 300°C to 1000°C, or from 400°C to 650°C, or from 450°C to 600°C, or from 500°C to 575°C. the polymer or polymer mixture comprises at least 80% by weight of polyethylene or polypropylene, or a combination of both; the polymer or polymer mixture comprises at least 80% by weight of PET or other polyester; the gaseous raw product mixture comprises at least 20% by weight of olefins or at least 50% by weight of olefins, in some embodiments in the range of 20 to 90% by weight; the mass yield of olefins 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 20% to 70%, or 30% to 65%, or 45% to 60%, based on the mass in the polymer feed; the reactor is a fluidized bed reactor; the catalyst is a solid catalyst, and the pyrolysis step is carried out in the fluidized bed reactor in the presence of the solid catalyst to produce a fluid product stream and a spent catalyst having coke, and at least 95% of the carbon in the feed is converted to coke and volatile products; The process may be characterized by one or any combination of the following: transferring at least a portion of the spent catalyst with coke to a regenerator where the coke reacts with oxygen to form a high-temperature regenerated catalyst, and returning at least a portion of the high-temperature regenerated catalyst to a fluidized-bed reactor, where heat from the high-temperature regenerated catalyst provides energy for the pyrolysis step; combusting at least a portion of the gas in the product mixture in the regenerator; subjecting the gaseous raw product mixture to a separation process to produce a gas stream enriched in CO and H, and passing at least a portion of the gas stream enriched in CO and H to a regenerator where the enriched gas stream is combusted; the polymer or polymer mixture comprises polyethylene, polypropylene, or polystyrene, or a mixture thereof; the gaseous raw product mixture comprises H and CO; and 10 to 25 wt. % of the H and CO are combusted in the regenerator. As with all descriptions of the present invention, in some embodiments, the term "comprises" may be replaced with the term "consisting essentially of" or "consisting of."

[0015] In another aspect, the present invention provides a method for catalytically pyrolyzing a mixed feed of material, the method comprising: providing a first stream comprising a polymer; adding a coke-forming material to form a mixed feed of materials; adding the mixed feed of materials to a fluidized bed reactor; pyrolyzing the mixed feed in the fluidized bed reactor in the presence of a solid catalyst to produce a fluid product stream and a coke-bearing spent catalyst, wherein at least 95% of the carbon in the mixed feed is converted to coke and volatile products; transferring at least a portion of the coke-bearing spent catalyst to a regenerator where the coke reacts with oxygen to form a high-temperature regenerated catalyst; and returning at least a portion of the high-temperature regenerated catalyst to the fluidized bed reactor, wherein heat from the high-temperature regenerated catalyst provides energy for the pyrolysis step; providing at least 90% of the energy to the pyrolysis step, wherein the first stream has properties such that when a stream consisting solely of the first stream undergoes a pyrolysis step and all of the spent catalyst with coke is transferred to a regenerator where the coke is burned with oxygen to form hot regenerated catalyst and hot combustion gases, and all of the hot regenerated catalyst is returned to the fluidized bed reactor, with heat from the hot regenerated catalyst providing energy for the pyrolysis step, the heat provided by the combustion of the coke, including the heat of the catalyst and the heat recovered from the combustion gases, provides less energy than the minimum energy required for a catalytic pyrolysis process in which at least 95% of the carbon in the first stream is converted to coke and volatile products; or (b) heat from the combustion of the coke and a portion of the volatile products provides at least 90% of the energy for the pyrolysis step, wherein the first stream has properties such that when a stream consisting solely of the first stream undergoes the pyrolysis step and all of the spent catalyst with coke and a portion of the volatile products are transferred to a regenerator where the coke and a portion of the volatile products are combusted with oxygen to form hot regenerated catalyst and hot combustion gases, and all of the hot regenerated catalyst is returned to the fluidized bed reactor, and the heat from the hot regenerated catalyst provides energy for the pyrolysis step, the heat provided by the combustion of the coke, including the heat of the catalyst and the heat recovered from the combustion gases, provides less energy than the minimum energy required for a catalytic pyrolysis process in which at least 95% of the carbon in the first stream is converted to coke and volatile products; A method is provided in which the addition of coke-forming material to a mixed feed results in sufficient coke to provide at least the minimum energy required for a catalytic pyrolysis process in which at least 95% of the carbon in the mixed feed is converted to coke and volatile products. Note that these calculations are performed assuming the mixed feed is added to the fluidized bed reactor at a constant rate.

[0016] This embodiment may be further characterized by one or any combination of the above-mentioned features or the following features: heat from the combustion of the portion of the coke and volatile products provides at least 90% of the energy to the pyrolysis step, and the portion of the combusted volatile products comprises a CO and H enriched stream separated from the volatile products; heat from the combustion of the portion of the coke and volatile products provides at least 90% of the energy to the pyrolysis step, and the portion of the combusted volatile products comprises a fraction of the gas mixture recovered after removing C5+ products from the volatile products; the mixed feed material is selected from the group consisting of biomass, polyethylene (PE), polypropylene (PP), polyacetylene, polybutylene, polyolefin, polyethylene terephthalate (PET), polybutylene terephthalate, copolyester, polyester, polycarbonate, polyurethane, polyamide, polystyrene (PS), polyacetal, epoxy, polycyanurate, polyacrylic acid, polyurea, vinyl ester, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride (PVC), polyvinyl acetate the polymer is selected from polyethylene, polypropylene, and polystyrene, or a mixture thereof, and the high coke-forming material is selected from biomass, polyethylene terephthalate, tires, cellulose, cellulose acetate, cotton clothing, and nylon, or a mixture thereof; the polymer is selected from polyethylene, polypropylene, and polystyrene, or a mixture thereof, and the high coke-forming material is selected from biomass, polyethylene terephthalate, tires, cellulose, cellulose acetate, cotton clothing, and nylon, or a mixture thereof;The reaction is carried out in a fluidized bed, circulating bed, bubbling bed, or riser reactor at an operating temperature ranging from 300°C to 1000°C, or from 400°C to 650°C, or from 450°C to 600°C, or from 500°C to 575°C; a stream enriched in ethylene or propylene, or both, is separated from the volatile products; the volatile products contain at least 10% by weight olefins, or at least 20% by weight olefins, in some embodiments in the range of 5 to 90% by weight olefins; a stream comprising C5+ products is separated from the volatile products; a stream enriched in benzene, toluene, xylene, or some combination thereof is separated from the volatile products; the mass yield of BTX is at least 10%, or at least 20%, or at least 25%, or at least 30%, or at least 35%, or at least 40%, or from 10% to 70%, or from 20% to 65%, or from 25% to 60%, based on the mass in the polymer feed; and the mixed feed comprises 5 to 98, or 5 to 90, or 20 to 70, or 20 to 90, or 40 to 90, or 40 to 60 mass% of PE, PP, PS, or mixtures thereof, and the remainder of the mixed feed comprises at least 95 mass% of high coke forming materials; the mixed feed comprises 5 to 98, or 5 to 90, or 20 to 70, or 20 to 90, or 40 to 90, or 40 to 60 mass% of PE, PP, PS, or mixtures thereof; and 2 to 60, or 10 to 60, or 10 It may be further characterized by one or any combination of the following: comprising ~50, or 15-25, or 2-15, or 2-6, or 2-5, or 3-4 wt.% high coke forming material, or 20-60, or 4-15 wt.% PET, or 2-50, or 10-50, or 2-3 wt.% biomass, or 2-55, or 10-50, or 40-55, or 5-20, or 2-5 wt.% tire polymer (not including the weight of contaminants);

[0017] In yet another aspect, the present invention provides a method for catalytically pyrolyzing a mixed feed of materials, comprising: adding a first stream comprising a polymer into a fluidized bed reactor; pyrolyzing the polymer in the fluidized bed reactor in the presence of a solid catalyst to produce a fluid product stream and a coked spent catalyst, wherein at least 95% of the carbon in the mixed feed is converted to coke and volatile products; transferring at least a portion of the coked spent catalyst to a regenerator where the coke reacts with oxygen to form a high-temperature regenerated catalyst; and returning at least a portion of the high-temperature regenerated catalyst to the fluidized bed reactor, wherein heat from the high-temperature regenerated catalyst provides energy for the pyrolysis step; wherein the first stream is a stream consisting solely of the first stream. wherein the first stream has properties such that when the first stream undergoes a pyrolysis step and all of the spent catalyst with coke is transferred to a regenerator where the coke is burned with oxygen to form high temperature regenerated catalyst and hot combustion gases, and all of the high temperature regenerated catalyst is returned to the fluidized bed reactor, and heat from the high temperature regenerated catalyst provides energy for the pyrolysis step, the heat provided by the combustion of the coke, including the heat of the catalyst and the heat recovered from the combustion gases, provides energy that is less than the minimum energy required for a catalytic pyrolysis process in which at least 95% of the carbon in the first stream is converted to coke and volatile products, and an amount of oxygen is introduced into the first stream such that there is sufficient energy to convert at least 95% of the carbon in the first stream to coke and volatile products.

[0018] This embodiment may be further characterized by one or any combination of the features described above, or by one or any combination of the following features: the amount of oxygen introduced into the process stream is 0.6% to 10%, 0.6% to 8%, 1% to 6%, or 2% to 4%, or at least 0.5%, at least 2%, at least 4%, or at least 6% by weight of the mass of the first stream; the oxygen is preferably introduced by the addition of air or O2 as a component of the fluidizing fluid, or in a gas injected with the plastic, or by separate direct injection into the fluidized bed, or some combination thereof.

[0019] In another aspect, the present invention provides a method for catalytically pyrolyzing a polymer-containing feed in a fluidized bed reactor, wherein the amount of oxygen introduced into the process is at least sufficient so that combustion of the feed material or other components with the introduced oxygen raises the temperature of the reaction mixture by at least 25°C, or at least 100°C, or at least 200°C, or at least 300°C, or from 100°C to 400°C. In some embodiments, the amount of oxygen introduced into the process stream is 0.6% to 10%, 0.6% to 8%, 1% to 6%, or 2% to 4%, or at least 0.5%, at least 2%, at least 4%, or at least 6% by weight of the mass of the mixed feed. In some embodiments, the oxygen is introduced by the addition of air or O2, preferably as a component of the fluidizing fluid, or in a gas injected with the plastic, or by separate direct injection into the fluidized bed, or some combination thereof.

[0020] In a further aspect, the present invention provides a method for producing aromatics or olefins, or a mixture thereof, comprising feeding a polymer or a polymer mixture to a fluidized bed, circulating bed, bubbling bed or riser reactor; pyrolyzing the material in the reactor in the presence of a catalyst under reaction conditions sufficient to produce a gaseous raw product mixture comprising one or more olefins or one or more aromatic compounds, or both; and introducing at least a fraction of the gaseous raw product mixture into a process stream in a steam cracking facility.

[0021] This embodiment may be further characterized by one or any combination of the features described above, or the following features: further comprising separating the stream enriched in olefins, aromatics, or both into streams in a steam cracking facility; further comprising separating and purifying the olefins or aromatics, or both the olefins and aromatics, in the steam cracking facility; the catalyst circulating in the catalytic pyrolysis unit is heated by the steam cracker product gas, at least a portion of which is recycled to the catalytic pyrolysis process reactor; the high temperature vapor product from the catalytic conversion of plastics is introduced into a quench tower of the steam cracking facility along with the steam cracker gas and vapor product; at least a portion of the methane produced in the steam cracking facility is included as a fluidizing fluid in the plastic catalytic pyrolysis process; the hydrogen produced in the steam cracking process or the hydrogen produced in the catalytic pyrolysis, or some combination thereof, is used in the process (a) of the present invention to produce acetylene, methyl acetylene / propylene. (b) hydrogenating dienes, pyrolysis gasoline, or other products, or some combination thereof, or (b) hydrotreating aromatics, paraffins, or some combination thereof to reduce their sulfur, nitrogen, oxygen, triene, diene, and styrene content, or (c) some combination of hydrogenation and hydrotreating; at least a portion of the stream containing ethane and propane, or C4 olefins and paraffins, or a combination thereof, is recycled to the steam cracker to produce additional ethylene and propylene, or recycled as a component of the fluidization gas to the plastic catalytic pyrolysis reactor; at least a portion of the pyrolysis gasoline naphtha and a portion of the condensable stream of naphtha from the plastic catalytic pyrolysis are hydrotreated to reduce the concentration of dienes, trienes, acetylenes, or vinyl aromatics (e.g., styrene), or some combination thereof, and to reduce the concentration of trace heteroatoms, sulfur, nitrogen, chlorine, or oxygen, or some combination thereof;The process may be further characterized by one or any combination of the following: the hydroprocessing product is further separated and purified to produce polymer-grade benzene, toluene, p-xylene, or some combination thereof; the catalyst used in the catalytic pyrolysis comprises a zeolite; the zeolite has a constraint index in the range of 1 to 12; the zeolite is ZSM-5; at least a portion of the feed mixture is heated to provide a molten mass that is hot filtered to remove suspended solids; the pyrolysis step comprises fast solid-state pyrolysis in the presence of a catalyst; the catalyst comprises a zeolite; the catalytic pyrolysis reaction is carried out in a fluidized bed, a circulating bed, a bubbling bed, or a riser reactor at an operating temperature in the range of 300°C to 1000°C, or 400°C to 650°C, or 450°C to 600°C, or 500°C to 575°C;

[0022] In another aspect, the present invention provides a feed mixture for a catalytic pyrolysis process comprising 10 to 95, or at least 10, 20, 30, 50, 60, or 10 to 80 wt. % polymer, the remainder being at least 95 wt. % highly coke-forming material.

[0023] In some embodiments, at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or between 5% and 60%, or between 10% and 60%, or between 20% and 60%, or between 40% and 60%, by weight of the feed comprises high coke-forming material. In some preferred embodiments, the polymer comprises polyethylene, polypropylene, polystyrene, or some combination thereof. In some embodiments, the high coke-forming material is biomass, tire sidewall, tire tread, or some combination thereof.

[0024] In some embodiments, the mixture comprises between 0.1% and 3% by weight, or between 0.2% and 2% by weight, or between 0.4% and 1% by weight, or at least 0.1% by weight, or at least 0.2% by weight, or at least 0.3% by weight, or at least 0.5% by weight, or less than 3% by weight, or less than 2% by weight, or less than 1% by weight of contaminants.

[0025] In another aspect, the present invention provides a feed mixture for a catalytic pyrolysis process comprising 10 to 99% by weight of polymer, or at least 30, 50, 80, 90, or 50 to 99% by weight of polyethylene, polypropylene, polystyrene, or mixtures thereof, and at least 1%, or at least 2%, or at least 3%, or at least 4%, or at least 10%, or 0.5% to 20%, or 1% to 15%, or 2% to 13% by weight of high coke-forming material, wherein the sum of the weights of the polymer and the high coke-forming material is 100% by weight.

[0026] This embodiment has the following features: the high coke-forming material is biomass, cellulose, cotton clothing, PET, PET clothing, cellulose acetate, or some combination thereof; the mixture contains 1% to 10% by weight, or 2% to 8% by weight, or 4% to 7% by weight, or at least 1% by weight, or at least 2% by weight, or at least 3% by weight, or at least 5% by weight of contaminants prior to any contaminant removal process; the high coke-forming material is at least partially pretreated to remove contaminants prior to addition to the catalytic pyrolysis process. reducing contaminant concentrations in the material removal process; at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or 5% to 60%, or 10% to 60%, or 20% to 60%, or 40% to 60%, by weight of the feed comprises high coke forming materials, with the remainder being at least 95% polymer.

[0027] The invention also includes systems comprising these feed mixtures and a pyrolysis reactor, e.g., any of the feed mixtures described herein within any of the reactor types described herein. The systems can be further characterized by any of the conditions described herein.

[0028] In any of the aspects of the present invention, the term "coke" includes both coke and char. Typically, in the catalytic pyrolysis of plastics, very little char is formed.

[0029] The present invention provides an efficient, environmentally friendly, and cost-effective method for recycling waste plastics to produce useful chemicals without the need to supply energy from an external source. [Brief explanation of the drawings]

[0030] [Figure 1]FIG. 1 depicts a schematic diagram of an energy recovery and integration scheme in a process for converting plastics into useful products such as BTX and olefins. [Figure 2] 1 depicts a schematic diagram of a process in which olefins are separated from the product mixture and upgraded to BTX. [Figure 3] Figure 1 shows a schematic diagram of a process in which olefins are separated from the product and unconverted olefins are recycled to the catalytic pyrolysis reactor for upgrading to BTX. [Figure 4] FIG. 1 depicts a schematic diagram of a process in which olefins are separated from the product and recycled to the catalytic pyrolysis reactor for further processing. [Figure 5] FIG. 1 shows a schematic diagram of a process where a coke-forming feed is pyrolyzed in a separate reactor, steam is introduced to the Plas-TCat process, and the solids are combusted separately to generate energy for the process. [Figure 6] FIG. 1 is a simplified general process flow diagram for a steam cracker reactor and downstream product recovery and separation procedures. [Figure 7] Schematic of a drop tube reactor. [Figure 8] 1 shows the steady-state loading of inert contaminants (e.g., silica) on the catalyst as a function of catalyst exchange rate when tires containing 7% inert contaminants are fed as coke-forming feed with polyethylene in a catalytic pyrolysis process. [Figure 9] 1 shows the steady-state loading of inert contaminants (e.g., silica) on the catalyst as a function of catalyst exchange rate when biomass containing 0.4% inert contaminants is fed as a coke-forming feed along with polyethylene in a catalytic pyrolysis process. [Figure 10] A tire containing 7% inert contaminants (e.g., silica) is pre-pyrolyzed in a separate process to remove 99% of the inert contaminants, showing the steady-state loading of inert contaminants on the catalyst as a function of catalyst exchange rate when steam is fed with polyethylene in a catalytic pyrolysis process. DETAILED DESCRIPTION OF THE INVENTION

[0031] The feed material mixture may include waste plastics, polymers, or other materials such that combustion of selected by-products of catalytic pyrolysis in a catalytic regenerator or otherwise generates sufficient energy to drive the catalytic pyrolysis conversion process, separation of useful products of the catalytic pyrolysis conversion process, upgrading of the catalytic pyrolysis conversion products, or some combination thereof. In some embodiments, the energy from combustion of the by-products exceeds the energy needed within the plant, and the energy may be converted to electrical energy for delivery to the grid or elsewhere.

[0032] In some embodiments, any of the aspects of the invention can be characterized by one or any combination of the following features: the polymer is selected from among polyethylene, polypropylene, polystyrene, or mixtures thereof; the feed mixture to the catalytic pyrolysis process can include biomass, polyethylene terephthalate, tires, cellulose, cellulose acetate, cotton clothing, and nylon, or mixtures thereof; the mixture of feed materials is selected such that the amount of solid carbonaceous products, such as coke and char, produced in the catalytic pyrolysis process is at least sufficient to provide the energy required for the process upon combustion of the solids in a catalyst regenerator or otherwise; the mixture of feed materials is selected such that the amount of solid carbonaceous products and a portion of the gaseous products produced in the catalytic pyrolysis process is at least sufficient to provide the energy required for the process upon combustion in a catalyst regenerator or otherwise; the mixture of feed materials is selected such that the amount of solid carbonaceous products and a portion of the olefin-depleted mixture of gases separated from the gaseous products produced in the catalytic pyrolysis process is at least sufficient to provide the energy required for the process upon combustion in a catalyst regenerator or otherwise.

[0033] In one aspect, an olefin stream is produced by catalytic pyrolysis of a polymer and separated for upgrading to valuable products. In another aspect, the present invention provides a method for producing one or more olefin products from a polymeric material or a co-polymerized polymeric material. Accordingly, the present invention has particular utility in plastics recycling. In this method, a polymer, or more typically a polymer mixture, is fed to a reactor, and at least a portion of the material is pyrolyzed in the reactor in the presence of a catalyst under reaction conditions sufficient to produce one or more olefins. In some preferred embodiments, the present invention can be characterized by surprisingly high yields of ethylene and / or propylene. The olefins can be separated from the gaseous raw product mixture for subsequent conversion in another process. Olefin conversion processes can include, for example, hydrogenation, hydrolysis, hydroformylation, cyclization, dimerization, polymerization, alkylation, or other conversion processes or combinations of conversion processes. However, the present invention is not limited to these conversion processes. In some embodiments, the conversion process comprises one or any combination of the following steps: conversion of olefins to alcohols or ethers; low temperature (80-400° C.) polymerization of olefins; reaction with CO to form carboxylic acids or aldehydes; alkylation with aromatics to form alkylated aromatics, and hydrogenation to paraffins.

[0034] The gaseous product stream from the catalytic pyrolysis process may be separated into an olefin-lean stream and an olefin-rich stream, and at least a portion of the olefin-rich stream coming from the olefin separator may be purified before being converted into valuable products.

[0035] In some embodiments, the gaseous raw product mixture produced by the present process (the vapor-phase product leaving the fluidized bed reactor before any separation steps occurring outside the reactor) comprises at least 20% by weight olefins, or at least 50% by weight olefins, and in some embodiments, in the range of 20% to 90% by weight olefins. In some embodiments, the mass yield of olefins 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 20% to 70%, or 30% to 65%, or 45% to 60%, based on the mass in the polymer feed.

[0036] The process may produce a BTX mixture upon product separation. In some embodiments, the mass yield of BTX is at least 10%, or at least 20%, or at least 25%, or at least 30%, or at least 35%, or at least 40%, or between 10% and 70%, or between 20% and 65%, or between 25% and 60%, based on the mass in the polymer feed.

[0037] The present invention also includes chemical systems that include the devices and compositions described herein. The present invention further includes chemical compositions that occur as intermediates or end products described herein or that are obtained from the methods described herein. For example, the present invention includes olefin conversion products that additionally contain polyolefins, alcohols, aldehydes, acids, or other higher-hydric chemicals.

[0038] In some embodiments, the feed composition comprises a mixture of polymeric material and catalyst. The mixture may comprise, for example, solids, liquids, and / or gases. In certain embodiments, the mixture comprises a composition of solid catalyst and solid polymeric material. In other embodiments, the catalyst may be provided separately from the polymer feed stream.

[0039] In some embodiments, for example, when recycled polymer materials are used, impurities can be optionally removed from the feed composition before being fed to the reactor, for example, by an optional purification step. In some cases, the particle size of the solid polymer feed composition can be reduced in a size reduction system before passing the feed to the catalytic pyrolysis reactor. In some embodiments, the average diameter of the reduced-size feed composition exiting the size reduction system can comprise about 50% or less, about 25% or less, about 10% or less, about 5% or less, or about 2% or less of the mass average diameter of the feed composition fed to the grinding system. The feed mixture can comprise 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) sieve, or the feed comprises a plastic mixture in which at least 85%, or at least 90%, or at least 95%, by weight, of the particles have an aspect ratio (length to width ratio) of 2:1, or 3:1, or 5:1, or 10:1, or 40:1, or 77:1, or 1:1 to 100:1, or 1.5:1 to 40:1, or 2:1 to 10:1. The average diameter (size) can be measured by sieving through a mesh (sieve). Large particle feed materials may be more easily transportable and less difficult to process than small particle feed materials. On the other hand, in some cases (as discussed below), it may be advantageous to feed small particles to the reactor. The use of a size reduction system also allows for the transport of large particle feed between the source and the process, while still allowing for the feeding of small particles to the reactor.

[0040] In processes in which catalyst from catalytic pyrolysis is regenerated, heat is generated by oxidation of coke, char, and other materials in a catalyst regenerator for use in the process or for conversion to electricity for export. In one set of embodiments, an oxidant is supplied to the regenerator via the stream shown as "Air" in FIG. 1. The oxidant can originate from any source, including, for example, oxygen, atmospheric air, or a steam tank, among others. In the regenerator, the catalyst is reactivated by reacting with the oxidant, generating heat. The solid mixture containing the deactivated catalyst can include residual carbon and / or coke from the process, as well as coke or char, 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 to be combusted with the solid materials. The gaseous products can first be separated into an olefin-rich stream and an olefin-lean stream, with at least a portion of the olefin-lean stream being supplied to the catalyst regenerator. The regenerator in FIG. 1 includes an exhaust stream that can include regenerated reaction products, residual oxidant, etc.

[0041] Figure 1 depicts a schematic diagram of the process of the present invention. A feed mixture of plastics and other materials is fed to a Plas-TCat fluidized-bed catalytic pyrolysis reactor where the feed mixture reacts to form a vapor product stream and a solid catalyst-containing stream. The catalyst-containing stream is passed to a catalyst regenerator, where it is contacted with an oxidizing gas, such as air, to regenerate the catalyst and generate energy from combustion. Energy for use in the process, such as for heating the feed material or recycling gases, or for other purposes, can be recovered from the hot combustion gases produced in the regenerator by heat exchange in one or more heat exchangers. The vapor product stream from the catalytic pyrolysis is separated into a useful product stream containing olefins and aromatics and a by-product stream containing methane, ethane, propane, H2, CO2, and CO. Optionally, a portion of the by-product gas stream can be passed to the regenerator to increase the heat generated therein. A portion of the energy generated in the catalyst regenerator can be used as thermal energy in the catalytic pyrolysis reactor, or for product separation, or both, or the energy can be converted to electrical energy, or the generated energy can be used or exported as thermal and electrical energy within the plant. At least a portion of the regenerated catalyst is returned to the catalytic pyrolysis reactor.

[0042] As shown in the exemplary embodiment of Figure 1, the regenerated catalyst can exit the regenerator and be recycled back to the catalytic pyrolysis reactor via a recycle stream. In some cases, catalyst may be lost from the system during operation. In some such cases, and in other cases, additional "make-up" catalyst may be added to the system via a make-up stream. Although not shown in Figure 1, the regenerated catalyst and make-up catalyst may be fed to the reactor along with the fluidization fluid via a recycle stream, although in other embodiments, the catalyst and fluidization fluid may be fed to the reactor via separate streams.

[0043] Olefins can be separated from the product mixture of the polymer conversion and upgraded to BTX in a separate process, as shown in Figure 2. While this is not shown in the diagram, unconverted olefins from the olefins-to-aromatics step can be recycled to the olefins-to-aromatics process. In this embodiment of the invention, the product stream from the Plas-TCat reactor and the olefins-to-aromatics process can be treated separately, allowing for greater flexibility in product purification or other opportunities for integration with other facilities. The olefins-to-aromatics conversion process can be shared with another process or can be an existing plant whose yield or efficiency is improved by integration with the process of the present invention. Advantages include reduced infrastructure needs and a cost- and energy-intensive separation scheme.

[0044] Figure 3 illustrates an embodiment of a process in which olefins are separated from the catalytic pyrolysis product for upgrading to BTX and at least a portion of the unconverted olefins are recycled to the catalytic pyrolysis (Plas-TCat) reactor. This configuration of the inventive process utilizes the ability of the Plas-TCat process to convert olefins to aromatics, improving the yield of aromatics from the Plas-TCat reactor and improving the efficiency of the overall process. In this embodiment of the invention, the products of the Plas-TCat and olefins-to-aromatics process can be treated separately or combined for purification and separation into desired products of value.

[0045] Another embodiment of the process of the present invention is depicted in Figure 4, in which at least a portion of the olefins produced are separated from the product of the Plas-TCat process and recycled to the catalytic pyrolysis (Plas-TCat) reactor for further processing and conversion to useful products. In this embodiment, the number of unit operations is minimized, reducing capital investment compared to some other embodiments of the process, and this embodiment may be more applicable to stand-alone plants where opportunities for integration with nearby processes are not available.

[0046] In another embodiment of the inventive process, as shown schematically in Figure 5, the coke-forming feed is pyrolyzed in a separate reactor, the vapors from the pyrolysis are introduced into the Plas-TCat process, and the solids from the pyrolysis are combusted separately to generate energy for the process. This embodiment has the advantage of using a feed to the pyrolysis unit that contains contaminants that may damage or deactivate the Plas-TCat catalyst, or that may otherwise present problems for product purification and separation, or that may simply accumulate during the process. In this scheme, non-volatile contaminants, such as silica, alumina, sand, etc., are primarily retained in the solids and are not sent to the Plas-TCat process to avoid poisoning the catalyst.

[0047] The mixed polymer feed to the process comprises one or any combination selected from the following materials: biomass, polyethylene (PE), polypropylene (PP), polyacetylene, polybutylene, polyolefin, polyethylene terephthalate (PET), polybutylene terephthalate, copolyester, polyester, polycarbonate, polyurethane, polyamide, polystyrene (PS), polyacetal, epoxy, polycyanurate, polyacrylic acid, polyurea, vinyl ester, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride (PVC), polyvinyl acetate, nylon, copolymers such as ethylene-propylene, EPDM, 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, filled polymers, polymer composites, plastic alloys, other polymeric materials, and polymers or plastics dissolved in a solvent. The feed material may include materials obtained from polymer or plastic manufacturing processes as waste, or materials separated from waste streams such as disposal materials, post-consumer recycled polymeric materials, municipal solid waste, black liquor, wood waste, or other biologically produced materials. The feed mixture contains materials that, when subjected to catalytic pyrolysis in a fluidized bed reactor, produce sufficient coke and light gases such as CO, H2, CH4, CH6, CH8, etc., so that, when combusted in a catalyst regenerator or other device, combustion of the coke, or a portion of the coke and light gases, produces sufficient energy to sustain the catalytic pyrolysis process without the addition of energy from external sources such as the combustion of natural gas, oil, coal, or other materials, or electrical energy, or energy produced from materials other than the by-products of the process of the present invention.

[0048] In some embodiments, the feed mixture includes added high coke-forming materials in addition to polyethylene, polypropylene, polystyrene, or mixtures thereof, such that at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or between 5% and 60%, or between 10% and 60%, or between 20% and 60%, or between 40% and 60%, by weight, of the feed mixture contains material or materials that produce more than 1%, or more than 2%, or more than 5%, or more than 10%, or more than 20%, or more than 40%, or between 1% and 40%, or between 5% and 40%, or between 10% and 40%, by weight of coke and char upon catalytic pyrolysis of the added material in a standard drop tube experiment. The amount of coke and char is determined in a standard drop tube experiment using ZSM-5 as the catalyst according to the method and conditions as described in the Examples section. Unless otherwise specified, the phrase "standard drop tube experiment" refers to the method and conditions as described in the Examples using ZSM-5. Throughout this specification, the phrase "coke and char" is the same as "coke" in the Examples and refers to any black or gray carbonaceous solid material produced by pyrolysis.

[0049] In some embodiments, the feed mixture includes added high coke-forming materials in addition to polyethylene, or polypropylene, or polystyrene, or mixtures thereof, such that at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or 5% to 60%, or 10% to 60%, or 20% to 60%, or 40% to 60%, by weight of the feed mixture is greater than 1%, or greater than 2%, by weight in catalytic pyrolysis of the added material in a standard drop tube experiment. or greater than 5 wt%, or greater than 10 wt%, or greater than 20 wt%, or greater than 40 wt%, or 1 wt% to 40 wt%, or 5 wt% to 40 wt%, or 10 wt% to 40 wt% of coke and char producing material or materials, wherein the added material contains 0.1 wt% to 3 wt%, or 0.2 wt% to 2 wt%, or 0.4 wt% to 1 wt%, or at least 0.1 wt%, or at least 0.2 wt%, or at least 0.3 wt%, or at least 0.5 wt%, or less than 3 wt%, or less than 2 wt%, or less than 1 wt% of contaminants.

[0050] In some embodiments, the feed mixture includes, in addition to polyethylene, or polypropylene, or polystyrene, or mixtures thereof, added high coke-forming materials such that at least 1%, or at least 2%, or at least 3%, or at least 4%, or at least 10%, or 0.5% to 20%, or 1% to 15%, or 2% to 13%, by weight of the feed mixture contains material or materials that produce more than 1%, or more than 2%, or more than 5%, or more than 10%, or more than 20%, or more than 40%, or 5% to 40%, or 10% to 25% by weight of coke and char upon catalytic pyrolysis of the added material in a standard drop tube experiment.

[0051] In some embodiments, the feed mixture includes added high coke-forming materials in addition to polyethylene, or polypropylene, or polystyrene, or mixtures thereof, such that at least 1 wt. %, or at least 2 wt. %, or at least 3 wt. %, or at least 4 wt. %, or at least 10 wt. %, or 0.5 wt. % to 20 wt. %, or 1 wt. % to 15 wt. %, or 2 wt. % to 13 wt. % of the feed mixture exceeds 1 wt. %, or 2 wt. %, when the added materials are catalytically pyrolyzed in a standard drop tube experiment. %, or greater than 5%, or greater than 10%, or greater than 20%, or greater than 40%, or between 5% and 40%, or between 10% and 25% by weight of coke and char producing material or materials, and the added material contains between 1% and 10% by weight, or between 2% and 8%, or between 4% and 7%, or at least 1%, or 2%, or at least 3%, or at least 5% by weight of contaminants before any contaminant removal process.

[0052] In some embodiments, the added material used in the process is at least partially pretreated prior to addition to the catalytic pyrolysis process to reduce the contaminant concentration in the contaminant removal process. "Contaminants" are materials such as silica or metals or metal oxides that do not pyrolyze under typical pyrolysis conditions. Removal can be achieved without adding a catalyst (or without a zeolite catalyst) by filtering the solids from the solution or melt, or in some preferred embodiments, by a first pyrolysis step, which in some embodiments is not in a fluidized bed. The contaminant removal process can be any of the methods described in U.S. Pat. Nos. 10,336,628, 6,792,881, 7,303,649, 7,503,981, 8,101,024, 9,109,049, 9,468,950, and U.S. Patent Application Publication No. 2015 / 0166683, or any method known to those skilled in the art.

[0053] The preferred composition of the feed can be estimated by calculating a linear combination of the yields of coke, or coke and a portion of the by-product gases, from each of the feed components and comparing the energy produced by combustion of the coke and by-product gas mixture to the energy required for the catalytic pyrolysis process, which can also be calculated from the components of the feed mixture and the processing steps. The energy required for the catalytic pyrolysis process can be estimated by the sum of 1) the energy difference between the heat to form the products and the heat to form the feed material, and 2) the energy lost in the conversion process and the energy required for the conversion, separation, and purification processes.

[0054] In some embodiments, it may be advantageous to supply the polymer at least partially as a molten material. This can be done with a polymer or plastic alone, or as a mixture of polymers and plastics that melt at temperatures below 200°C. In some embodiments, the molten polymer can be atomized before entering the pyrolysis reactor. This can be done with a carrier gas injection or a gas mixture recycled from the pyrolysis product separation section. The gas mixture can include argon, helium, nitrogen, carbon dioxide, carbon monoxide, hydrogen, methane, ethane, propane, ethylene, or propylene, or a mixture thereof.

[0055] In some embodiments, the polymer or plastic, or molten mixture of polymer and plastic, can be filtered to remove solids that do not readily melt at the selected process conditions using any of a variety of filtration procedures known to those skilled in the art. In some embodiments, where the polymer or plastic, or molten mixture of polymer and plastic, includes materials containing carbonaceous solids, these solids can be separated by high-temperature filtration and optionally combusted to provide energy for the process.

[0056] The reactor used can be any suitable reactor known to those skilled in the art. For example, in some cases, the reactor can include a continuously stirred tank reactor (CSTR), a batch reactor, a semi-batch reactor, a fluidized bed reactor, or a fixed-bed catalytic reactor, among others. In some cases, the reactor includes a fluidized bed reactor, e.g., a moving bed reactor such as a circulating fluidized bed reactor, a riser reactor, or a bubbling bed reactor. A fluidized bed reactor can, in some cases, provide improved mixing of the catalyst and / or polymeric material during pyrolysis and / or subsequent reaction, which can lead to enhanced control over the reaction products formed. The use of a fluidized bed reactor can also lead to improved heat transfer within the reactor. In addition, improved mixing within a fluidized bed reactor can lead to a reduction in the amount of coke deposited on the catalyst, which in some cases can result in reduced catalyst deactivation and higher yields of olefins and other desirable products. Throughout this specification, various compositions are referred to as process streams, but it should be understood that the process can also be conducted in batch mode.

[0057] Suitable methods for separating olefins from other fluid hydrocarbon products are known to those skilled in the art. For example, olefins can be separated from other fluid hydrocarbon products by cooling the product stream to a temperature between the boiling point of the olefins and the boiling point of the other fluid hydrocarbon products. Optionally, the olefin separator can include multiple stage separators. For example, the olefin separator can include a first separator that separates gaseous products (including olefins) directly from liquid products (e.g., higher boiling point materials such as benzene, toluene, xylenes, higher olefins, higher paraffins, etc.) and a second separator that separates at least a portion of the olefins from other gaseous products (e.g., gaseous aromatics, methane, hydrogen, nitrogen, HCl, HCN, NH3, CO2, CO, HO, etc.). The method and / or conditions used to carry out the separation may depend on the relative amounts and types of compounds present in the fluid hydrocarbon product stream, and one skilled in the art will be able to select suitable methods and conditions to achieve a given separation, given the guidance provided herein.

[0058] In one set of embodiments, the separated catalyst can exit the catalytic pyrolysis reactor via a solids outlet conduit. In some cases, the catalyst exiting the catalytic pyrolysis reactor can be at least partially deactivated. The separated catalyst, in some embodiments, can be fed to a regenerator where any at least partially deactivated catalyst can be reactivated. In some embodiments, the regenerator can include an optional purge stream, which can be used to purge solids, such as coke, ash, and / or catalyst, from the regenerator.

[0059] The deactivated solid catalyst removed from the reactor can be mixed with solid carbon-containing material from the feed material or solid carbon-containing material that was in the feed mixture and not transformed in the catalytic pyrolysis process. For example, tires contain carbon black, a solid form of carbon that is not significantly transformed in the catalytic pyrolysis process. The carbon black mixed with the partially deactivated catalyst can be passed to a catalyst regenerator where it is oxidized (burned) along with the coke and any char on the catalyst created in the process to generate heat. The heat is recovered in the hot catalyst and from the combustion gases and used to provide thermal energy for the catalytic pyrolysis process, or optionally converted to electrical energy to operate equipment in the plant, such as distillation columns, compressors, pumps, fans, controllers, etc., or the electricity can be transmitted to other facilities or the grid, or some combination thereof.

[0060] In one set of embodiments, the oxidant is supplied to the regenerator via a gas feed stream. The oxidant can originate from any source, including, for example, oxygen, atmospheric air, recycled exhaust gas, or a steam tank, among others. In the regenerator, the catalyst is reactivated by reacting with the oxidant. In some cases, the deactivated catalyst can contain residual carbon and / or coke, which can be removed via reaction with the oxidant in the regenerator. The regenerator includes an exhaust stream that can include regeneration reaction products, residual oxidant, etc. The exhaust gas exhaust stream from the regenerator can be passed through a catalytic exhaust gas cleanup system to further reduce CO and hydrocarbon concentrations and reduce emissions emitted to the atmosphere. A portion of the exhaust gas exhaust stream can be recycled to the regenerator gas feed to control the heat release of the regeneration process.

[0061] The regenerator can be of any suitable size as described above in connection with the reactor or solids separator. Additionally, the regenerator can optionally be operated at high temperatures (e.g., at least about 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, or higher). The residence time of the catalyst in the regenerator can also be controlled using methods known to those skilled in the art, including those outlined above. In some cases, the mass flow rate of the catalyst through the regenerator is coupled to the flow rate(s) in the reactor and / or solids separator to maintain mass balance in the system.

[0062] The regenerated catalyst exits the regenerator and may be recycled back to the reactor via a catalyst recycle stream. In some cases, catalyst may be lost from the system during operation. In some cases, additional "make-up" catalyst may be added to the system via a make-up stream. While the regenerated catalyst and make-up catalyst may be fed to the fluidization fluid and reactor via a recycle stream, in other embodiments, the catalyst and fluidization fluid may be fed to the reactor via separate streams.

[0063] The reaction product (eg, a fluid hydrocarbon product) can be fed to a solids separator that can separate the solid catalyst from the fluid product.

[0064] In some cases, the initial products of the process may be fed to a quench tower, which is fed with a cooling fluid, preferably a liquid, along with the product stream to cool and condense the products. In some embodiments, the desired reaction product(s) (e.g., liquid aromatic hydrocarbons, olefinic hydrocarbons, gaseous products, etc.) may be recovered at any point in the production process (e.g., after passing through the reactor, after separation, after condensation, etc.).

[0065] In some embodiments, the reaction product is sent to a quench section to remove heavy hydrocarbons into a quench fluid. In some cases, the quench fluid contains liquid products that are recovered in a subsequent separation step. The gaseous stream from the quench section can be sent to a fractionation column, where various aromatic liquid components can be recovered. This quench section and fractionation column can operate at high pressures of 1 to 7 bara for more efficient liquid recovery. The gaseous stream from the top of the fractionation column can be sent to an absorption column, where the final fraction of remaining liquid organics is recovered. This can be done using a lean oil fraction as the absorption fluid, which can include the liquid products recovered from the fractionation column or other available liquids known to those skilled in the art. Here, a portion of the gaseous stream, removed from most of the high-boiling products, can be sent back to the reactor for further olefin conversion, and another portion can be sent to feed the olefin purification section.

[0066] Glossary Aromatic Compound—As used herein, the terms “aromatic” or “aromatic compound” are used to refer to hydrocarbon compounds or compounds that contain one or more aromatic groups, such as, for example, single aromatic ring systems (e.g., benzyl, phenyl, etc.) and fused polycyclic aromatic ring systems (e.g., naphthyl, 1,2,3,4-tetrahydronaphthyl, etc.). Examples of aromatic compounds include, but are not limited to, benzene, toluene, indane, indene, 2-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, and dimethyl-hydrindene. In some embodiments, single-ring and / or multi-ring aromatic compounds may also be produced.

[0067] Fluid—The term “fluid” refers to a gas, a liquid, a mixture of gas and liquid, or a gas or liquid containing dispersed solids, liquid droplets, and / or gaseous bubbles. The terms “gas” and “vapor” have the same meaning and are sometimes used interchangeably. In some embodiments, it may be advantageous to control the residence time of the fluidizing fluid within the reactor. The fluidizing residence time of the fluidizing fluid is defined as the volume of the reactor divided by the volumetric flow rate of the fluidizing fluid under process conditions of temperature and pressure.

[0068] Fluidized Bed Reactor—The term “fluidized bed reactor” is given its conventional meaning in the art and is used to refer to a reactor comprising a vessel that may contain particulate solid material (e.g., silica particles, catalyst particles, etc.) through which a fluid (e.g., gas or liquid) passes at a velocity high enough to suspend the solid material, causing it to behave as if it were a fluid. Examples of 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. 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 a particulate solid material passes out of the reactor, circulates through lines in fluid communication with the reactor, and is recycled back to the reactor. An example of a circulating fluidized bed reactor is described in Kirk-Othmer Encyclopedia of Chemical Technology (Online), Vol. 11, Hoboken, NJ: Wiley-Interscience, 2001, pages 791-825.

[0069] 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 is operated at a flow rate sufficiently low 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 greater than the flow rate employed in a bubbling fluidized bed reactor, and therefore bubbles and voids are not observed within the volume of the fluidized bed during operation. Examples of bubbling fluidized bed reactors and turbulent fluidized bed reactors are described in Kirk-Othmer Encyclopedia of Chemical Technology (online), Vol. 11, Hoboken, NJ: Wiley-Interscience, c2001-, pages 791-825, which is incorporated herein by reference.

[0070] Olefin—The terms “olefin” or “olefinic compound” (also “alkene”) are given their ordinary meaning in the art and are used to refer to any unsaturated hydrocarbon containing one or more pairs of carbon atoms linked by a double bond. Olefins include both cyclic olefins and acyclic (aliphatic) olefins, in which the double bond is located between carbon atoms forming part of a cyclic (closed ring) or open-chain group, respectively. In addition, 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 aromatic moieties are considered olefins, e.g., benzyl acrylate or styrene.

[0071] Catalyst—A catalyst component useful in the context of the present invention can be selected from any catalyst known or understood by those skilled in the art. A catalyst promotes and / or effects 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 (e.g., shape-selective catalysts) in a chemical reaction. Examples of reactions that can be catalyzed include dehydration, dehydrogenation, isomerization, hydrogen transfer, hydrogenation, polymerization, cyclization, desulfurization, denitrification, deoxygenation, aromatization, decarbonylation, decarboxylation, aldol condensation, and combinations thereof. The catalyst component can be considered acidic, neutral, or basic, as understood by those skilled in the art.

[0072] For catalytic pyrolysis, particularly advantageous catalysts include those containing internal porosity selected according to pore sizes (e.g., mesopores and pore sizes typically associated with zeolites), such as average pore sizes of less than about 100 angstroms, less than about 50 angstroms, less than about 20 angstroms, less than about 10 angstroms, less than about 5 angstroms, or even smaller. In some embodiments, catalysts having average pore sizes of about 5 angstroms to about 100 angstroms can be used. In some embodiments, catalysts having average pore sizes of about 5.5 angstroms to about 6.5 angstroms, or about 5.9 angstroms to about 6.3 angstroms can be used. In some cases, catalysts having average pore sizes of about 7 angstroms to about 8 angstroms, or about 7.2 angstroms to about 7.8 angstroms can be used.

[0073] In some preferred embodiments of catalytic pyrolysis, the catalyst may be selected from naturally occurring 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.

[0074] A simple determination of the Constraint Index can be made by continuously passing a mixture of equal weights of normal hexane and 3-methylpentane over a small sample of crystalline material, approximately 1 gram or less, at atmospheric pressure, according to the following procedure. A sample of crystalline material, in the form of pellets or extrudates, is crushed to a particle size similar to coarse sand and mounted in a glass tube. Prior to testing, the crystalline material is treated for at least 15 minutes in a stream of air at 537°C. The crystalline material is then flushed with helium at a controlled temperature of 287°C to 510°C or higher, allowing for an overall conversion of 10% to 60% when the hydrocarbon mixture is passed over the crystalline material with helium dilution at 1 space velocity (i.e., 1 volume of liquid hydrocarbon per volume of crystalline material per hour), giving a molar ratio of helium to total hydrocarbon of 4:1. After 20 minutes on stream, a sample of the effluent is analyzed, most conveniently by gas chromatography, to determine the fraction that remains unchanged for each of the two hydrocarbons. The Constraint Index is the ratio of the logarithm of the remaining n-hexane divided by the logarithm of the remaining 3-methylpentane. The Constraint Index approximates the ratio of the cracking rate constants for the two hydrocarbons. The method for determining the Constraint Index is more fully described in U.S. Pat. No. 4,029,716, which is incorporated by reference for details of the method.

[0075] Constraint Index (CI) values ​​for some typical materials are as follows:

[0076] [Table 1] CI values ​​typically characterize a given crystalline material, but are the cumulative result of several variables useful in its determination and calculation. Thus, for a given crystal, exhibiting a CI value within the range of 1 to 12 and with 10 to 60% conversion, depending on the temperature employed during the test method, the CI may vary within the indicated range of 1 to 12. Similarly, other variables, such as crystal size, or possibly the presence of occluding contaminants, and binders intimately associated with the crystal, may affect the CI. Those skilled in the art will recognize that the CI, while providing a very useful tool for characterizing a molecular sieve of interest, is an approximation, potentially compounding variable extremes in some cases, given the manner of its determination. However, in all cases, at temperatures within the range specified above, the CI for any given molecular sieve useful herein will have a value within the range of approximately 1 to 12.

[0077] In other embodiments, non-zeolitic catalysts, such as WOx / ZrO2, aluminum phosphate, and the like, can be used. In some embodiments, the catalyst can include a metal and / or metal oxide. Suitable metals and / or oxides include, for example, nickel, palladium, platinum, titanium, vanadium, chromium, manganese, iron, cobalt, zinc, copper, gallium, and / or any of their oxides, among others. In some cases, promoter elements selected from rare earth elements, i.e., elements 57-71, cerium, zirconium, or their oxides for combinations thereof, can 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.) can be tailored to selectively produce desired products.

[0078] Catalysts for other processes such as olefin alkylation, hydrogenation, hydrotreating, deoxygenation, denitrification, and desulfurization are well known and can be selected for the olefin conversion or other processes described herein.

[0079] Low and high coke forming materials Materials can be classified as high or low coke-forming by conducting simple experiments, such as those described in the Examples, using a drop tube reactor and ZSM-5 catalyst at either 500°C for plastics or similar materials and 525°C for biomass or similar materials. Low coke-forming materials are those that, when catalytically pyrolyzed in the presence of ZSM-5 according to the methods described in the Examples, produce less than 5% by weight of solid coke and char in the product mixture. High coke-forming materials are those that, when catalytically pyrolyzed in the presence of ZSM-5 according to the methods described in the Examples, produce more than 10% by weight of solid coke and char in the product mixture. Materials that, when catalytically pyrolyzed in the presence of ZSM-5 according to the methods described in the Examples, produce intermediate yields of coke and char, i.e., 5% to 10% by weight, can be considered either low or high coke-forming materials, depending on the other components of the mixture. In some embodiments of the present invention, 5% to 10% of the coke- and char-producing material may be mixed with low coke-forming material(s) to increase the coke produced so that combustion of the coke, or a portion of the coke and by-product gases, provides the energy required for the process. In other cases, 5% to 10% of the coke- and char-producing material may be mixed with high coke-forming material(s) in appropriate proportions so that combustion of the coke, or a portion of the coke and by-product gases, provided the energy required for the process.

[0080] 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 even greater than 10,000.

[0081] Pyrolysis—The terms “pyrolysis” and “pyrolyzing” are given their conventional meaning in the art and are used to refer to the thermal transformation of a compound, such as a solid hydrocarbonaceous material, into one or more other substances, such as volatile organic compounds, gases, and coke, preferably without the addition of O or in the absence of O. Preferably, the volume fraction of O 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 may involve steps as described in more detail below. Examples of catalytic pyrolysis processes are outlined, 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.

[0082] Selectivity—The term “selectivity” refers to the amount of a particular product produced compared to a selection of products. The selectivity for a product can be calculated by dividing the amount of a particular product by the amount of the number of products produced. For example, if 75 grams of aromatic compounds are produced in a reaction and 20 grams of benzene are found among these aromatic compounds, the selectivity for benzene in the aromatic products is 20 / 75=26.7%. Selectivity can be calculated on a mass basis, as in the previous example, or on a carbon basis, where selectivity is calculated by dividing the amount of carbon found in a particular product by the amount of carbon found in the selection of products. Unless otherwise specified, for reactions involving polymers as reactants, selectivity is on a mass basis. For reactions involving the conversion of a particular molecular reactant (e.g., ethene), selectivity is the percentage of the selected product (on a mass basis, unless otherwise specified) divided by all products produced.

[0083] Yield—The term yield is used herein to refer to the amount of product leaving a reactor divided by the amount of reactants entering the reactor, and is usually expressed as a percentage or fraction. Yields are often calculated on a mass basis, a carbon basis, or based on specific feed components. Mass yield is the mass of a specific product divided by the weight of the feed used to prepare that product. For example, if 500 grams of polymer are fed to a reactor and 45 grams of benzene are produced, the mass yield of benzene is 45 / 500 = 9% benzene. Carbon yield is the mass of carbon found in a specific product divided by the mass of carbon in the feed to the reactor. For example, if 500 grams of polymer containing 90% carbon are reacted to produce 400 grams of benzene containing 92.3% carbon, the carbon yield is [(400 * 0.923) / (500 * 0.90)] = 82.0%.

[0084] As standard patent terminology, the term "comprising" means "including" and does not exclude additional components. Any aspect of the invention described in conjunction with the term "comprising" also includes narrower embodiments in which the term "comprising" is replaced by the narrower term "consisting essentially of" or "consisting of." As used in this specification, the terms "includes" or "including" should not be construed as limiting the invention, but rather as listing exemplary components.

[0085] Description of Some Preferred Embodiments The various features, characteristics, embodiments, etc. described herein are not limited to a single aspect or embodiment, but should be understood as being applicable to any of the aspects of the invention described herein.

[0086] In one embodiment of the present invention, a polymer or plastic, or a polymer and plastic, is fed to a catalytic pyrolysis reactor to form a gaseous product containing aromatics and olefins, the olefins are separated from the product, the olefins are purified and separated into various component olefins, and each olefin stream is sent for further processing for conversion into useful products.

[0087] Since olefins are commonly produced, the present invention is generally applicable to any polymer pyrolysis reaction. Preferably, the polymer feedstock comprises a solid material. The pyrolysis reactor comprises a solid catalyst for fast catalytic pyrolysis. The type of reactor and the type of solid catalyst, if present, are not limited and may generally be of a type known for the conversion of polymeric materials to fluid hydrocarbonaceous streams. The conditions for catalytic pyrolysis of polymers may have the following characteristics (not intended to limit the broader aspects of the invention): a zeolite catalyst, a ZSM-5 catalyst; a microporous catalyst having a constraint index of 1 to 12; a zeolite catalyst containing one or more of the following metals: titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, platinum, palladium, silver, phosphorus, sodium, potassium, magnesium, calcium, tungsten, zirconium, cerium, lanthanum, and combinations thereof; a fluidized bed, circulating bed, bubbling bed, or riser reactor; an operating temperature in the range of 300°C to 1000°C, or 400°C to 650°C, or 450°C to 600°C, or 500°C to 575°C; a solids content of 0.1 to 20, or 0.5 to 15, or 1 to 10, or 3 to 8. a feed mass ratio of polymer to polymer; a space velocity in the range of 0.1 to 10, or 0.2 to 8, or 0.5 to 5, or 1 to 4; a pressure of 1 bara (actual bar) to 30 bara, or 2 bara to 15 bara, or 3 bara to 10 bara, or 4 to 7 bara, or at least 3 bara, or at least 4 bara, or at least 6 bara; or a feed residence time of 0.1 to 120 seconds, or 1 to 60 seconds, or 5 to 30 seconds, or 8 to 20 seconds, or less than 60 seconds, or less than 30 seconds, or less than 10 seconds, or less than 8 seconds (the feed residence time is calculated as the average time that the carbon atoms spend in the reactor at a temperature of at least 400°C under the actual conditions of temperature and pressure).

[0088] Pyrolysis processes are typically carried out in atmospheres with very low or zero oxygen (O), usually less than 0.5% by volume. Nevertheless, in some embodiments, the pyrolysis process can be carried out at concentrations of 0.6% by volume or greater O to rapidly raise the temperature of the mixture to the desired reaction temperature, or to overcome the endothermic nature of the process, or both. In some embodiments, the process feed is introduced at a temperature between 100°C and 450°C, and the temperature can be raised (swept) very rapidly to at least 25°C, or at least 100°C, or at least 200°C, or at least 300°C, or from 100°C to 400°C, by the use of small concentrations of O in the process. The introduction of oxygen initiates combustion of hydrocarbons, CO, H, or other components, or some combination, in the process, delivering the thermal energy needed to achieve conversion of the feed material. In these cases, the concentration of O2 in the reactor feed resulting from this addition can be 0.6 wt% to 10 wt%, 0.6 wt% to 8 wt%, 1 wt% to 6 wt%, or 2 wt% to 4 wt%, or at least 0.6 wt%, at least 2 wt%, at least 4 wt%, or at least 6 wt%, the percent weight of O2 being relative to the weight of the polymer feed mixture, but in all cases the introduced oxygen concentration is kept below the concentration at which significant unconverted oxygen would be found in the product mixture exiting the reactor. Oxygen is preferably introduced by the addition of air or O2 as a component of the fluidizing fluid, or in a gas injected with the plastic, or by separate direct injection into the fluidized bed, or some combination thereof.

[0089] Feed materials for the present process include one or more of the following materials: polyethylene, polypropylene, polyacetylene, polybutylene, polyolefin, polyethylene terephthalate (PET), polybutylene terephthalate, copolyester, polyester, polycarbonate, polyurethane, polyamide, polystyrene, polyacetal, epoxy, polycyanurate, polyacrylic acid, polyurea, vinyl ester, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride (PVC), polyvinyl acetate, nylon, copolymers such as ethylene-propylene, EPDM, 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, filled polymers, polymer composites, plastic alloys, and polymers or plastics dissolved in a solvent. The feed material may include materials obtained from polymer or plastic manufacturing processes as waste, or materials separated from waste streams such as disposal materials, post-consumer recycled polymeric materials, municipal solid waste, black liquor, or wood waste. In some embodiments, the feed stream contains at least 80, or at least 90, or at least 95 weight percent polyethylene or polypropylene, or a combination of both. In some embodiments, the feed stream contains at least 80, or at least 90, or at least 95 weight percent PET or polyester, or a combination of both. In some embodiments, the process is surprisingly tolerant to impurities such as halogens that are more destructive in conventional processes.

[0090] The molecular sieve or catalyst composition containing it for use herein can be heat-treated at elevated temperatures. This heat treatment is generally carried out by heating (typically in an oxygen-containing atmosphere, preferably air) at a temperature of at least 370°C for at least 1 minute and generally not longer than 20 hours. Subatmospheric pressures can be employed for the heat treatment, although atmospheric pressure is preferred for convenience. Heat treatment can be carried out at temperatures up to 925°C. Heat-treated products are particularly useful in the present process.

[0091] For catalyst compositions useful in the present invention, suitable molecular sieves may be employed in combination with a support or binder material, such as, for example, a porous inorganic oxide support or a clay binder. Non-limiting examples of such binder materials include alumina, zirconia, silica, magnesia, thoria, titania, boria, and combinations thereof, generally in the form of dried inorganic oxide gels and gelatinous precipitates. Suitable clay materials include, by way of example, bentonite, kieselguhr, and combinations thereof. The relative proportion of suitable crystalline molecular sieves in the total catalyst composition can vary widely, with molecular sieve content ranging from 30 to 90 weight percent of the composition, more usually from 40 to 70 weight percent. The catalyst composition may be in the form of extrudates, beads, or free-flowing particulates.

[0092] The molecular sieves for use herein or catalyst compositions containing same may have the original cations replaced, at least in part, by ion exchange with hydrogen or hydrogen precursor cations and / or non-noble metal ions of Group VIII of the periodic table, i.e., nickel, iron and / or cobalt, according to techniques well known in the art.

[0093] In broader aspects of the present invention, the olefin-containing product stream can have a wide variety of compositions. The fraction can simply be a gaseous (non-condensed) fraction containing CO, CO, ethylene, propylene, and numerous other components, and may contain more olefins. The olefin-containing product can also contain alkynes such as ethyne, propyne, and butyne. In other embodiments, the fraction can be a relatively olefin-rich stream separated from a relatively olefin-lean stream. Examples of separation techniques that can be used in polymer conversion systems include cryogenic separation, distillation, membrane separation, adsorptive separation, or reactive separation. In some preferred embodiments, the olefin-containing product contains at least 20% by weight olefins, in some embodiments at least 50% by weight olefins, and in some embodiments, in the range of 20 to 90% by weight or more olefins. Other gases in the olefin-containing fraction can include methane, ethane, propane, CO, CO, water, propadiene, methylacetylene, H, or N, or some combination thereof.

[0094] The olefin product stream from catalytic pyrolysis (the raw feed from pyrolysis before purification) can contain C2-C4 alkenes, including ethylene, propylene, butylene, and butadiene. The olefin content can range from 1 to 70 wt%, or 5 to 65 wt%, or 10 to 60 wt%, or 20 to 50 wt%, or 30 to 45 wt%, or 40 to 65 wt%, or 50 to 70 wt%, or at least 20 wt%, or at least 30 wt%, or at least 40 wt%, or at least 50 wt%, or at least 60 wt%. The mass ratio of ethylene to propylene can vary from 0.2 to 3, depending on the reaction conditions and feedstock. The mass ratio of butene to propylene can vary between 0.05 and 0.25. Other minor components, such as C5-C7 olefins, are present at much smaller mass ratios relative to propylene, generally less than 0.1.

[0095] In some embodiments, the mass yield of olefins 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 20% to 70%, or 30% to 65%, or 45% to 60%, based on the mass of the polymer or plastic feed. In some embodiments, the mass yield of BTX is at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, or 3% to 60%, or 5% to 50%, or 10% to 50%, or 20% to 50%, based on the mass of the plastic or polymer feed to the process. In some embodiments, the mass yield of coke and char is less than 10%, or less than 5%, or less than 2%, or less than 1%, or less than 0.5%, or 0.1% to 10%, or 0.2% to 5%, or 0.3% to 2%, based on the mass of the polymer or plastic feed. In some embodiments, the mass yield of olefins plus aromatics is greater than 60%, or greater than 70%, or greater than 80%, or greater than 85%, or greater than 90%, or between 70% and 99%, or between 80% and 98%, or between 85% and 95%, or between 90% and 93%, based on the mass in the polymer or plastic feed. In some embodiments, the selectivity of ethylene as a percentage of total olefins produced is at least 20%, or at least 25%, or at least 30%, or between 10% and 40%, or between 20% and 35%, or between 25% and 30%. In some embodiments, the selectivity of propylene as a percentage of total olefins produced is at least 20%, or at least 30%, or at least 40%, or at least 45%, or at least 50%, or between 20% and 70%, or between 30% and 65%, or between 45% and 55%.In some embodiments, the selectivity of benzene + toluene + xylenes as a percentage of aromatics produced is at least 70%, or at least 80%, or at least 90%, or at least 95%, or at least 97%, or between 70% and 99.9%, or between 80% and 99.5%, or between 90% and 99%, or between 95% and 98%.

[0096] The olefin mixture produced by the process of the present invention can be separated and purified by conventional cryogenic distillation, membrane separation, hybrid membrane distillation, selective adsorption, or facilitated transport systems, as known in the art. Impurities such as CO, HCl, HCN, or HS can be removed by amine or caustic scrubbing, or other conventional means known to those skilled in the art. Impurity removal can optionally be performed before or after separating the olefins from other vapor components.

[0097] The aromatic mixture produced by the process of the present invention can be separated and purified by conventional distillation, membrane separation, hybrid membrane distillation, selective adsorption, or facilitated transport systems, as known in the art. Impurities such as phenols, thiols, thiophenes, nitriles, amines, or other oxygen-, sulfur-, or nitrogen-containing impurities can be removed by hydrotreating or other conventional means known to those skilled in the art. Impurity removal can optionally be carried out before or after separation of the aromatic compounds from other condensable components.

[0098] In some embodiments, downstream conversion of the olefin-containing stream occurs in a catalyst-containing reactor, such as a packed-bed reactor. The conversion reactions may include (but are not limited to) one or more of the following reactions: hydrogenation, hydrolysis, hydroformylation, cyclization, dimerization, and / or polymerization. The conversion process can be carried out at a lower temperature than the thermal cracking process in a secondary reactor or in a lower temperature section of the thermal cracking reactor, with the temperature during olefin conversion preferably maintained below 400°C, and preferably in the range of 80°C to 400°C.

[0099] In some embodiments, the olefin-containing product stream is contacted with an acid catalyst under conditions to induce dimerization or oligomerization. The acid catalyst can be selected from among those known to those skilled in the art, including liquid acids such as H2SO4 or HNO3, supported acids such as sulfated zirconia, or solid acids such as solid phosphoric acid, zeolites, pillared clays, or amorphous silica-alumina mixtures. Preferred catalysts include solid phosphoric acid (such as phosphoric acid on kieselguare) or zeolites ZSM5, ZSM11, ZSM12, ZSM22, ZSM23, ZSM35, ZSM49, and MCM56. Regenerated catalysts, including regenerated ZSM5 from a thermal cracking process, can be used. The preferred temperature range is 120°C to 300°C, more preferably 150°C to 250°C, although higher temperatures can be used. The pressure is preferably in the range of 1 atm to 20 atm (100 kPa to 2,000 kPa), more preferably 1 to 5 atm (100 kPa to 500 kPa). Higher pressures can be used if higher olefin conversions are desired. The space velocity for dimerization / oligomerization is preferably in the range of 5 to 30 GHSV (gas hourly space velocity, the ratio of gas volumetric flow rate to reactor volume). The reaction can be carried out in various types of reactors, but is preferably carried out in a fixed-bed reactor. This reaction is most effective for the conversion of C3 and above; therefore, for mixtures containing ethylene and propylene, more propylene is typically consumed.

[0100] In one downstream conversion process, olefins are converted by alkylation of aromatic compounds. In this case, an olefin-containing stream is preferably mixed with an aromatics-containing stream and contacted with an acid catalyst. The acid catalyst can be selected from among acid catalysts known to those skilled in the art, including liquid acids such as H2SO4 or HNO3, supported acids such as sulfated zirconia, or solid acids such as solid phosphoric acid, zeolites, pillared clays, or amorphous silica-alumina mixtures.

[0101] Preferred catalysts include zeolite Y, such as ultrastable zeolite Y (USY), or zeolites ZSM5, ZSM11, ZSM12, ZSM22, ZSM23, ZSM35, and ZSM49. Zeolite catalysts are typically present with a binder, such as silica, alumina, or zirconia, or mixtures thereof. The catalyst can be promoted with a metal to improve performance and limit coke deposition. Any metal from the group consisting of metals with atomic numbers 21-31, 57-71, and the noble metals Pd, Pt, Ag, and Au, or combinations thereof, can be used. More preferably, the catalyst contains Pd, Pt, or combinations thereof. Combinations of Pt and / or Pd with Ru, Ir, Rh, Cu, Re, Ag, and / or Au are also desirable. More preferably, in addition to Pt and / or Pd, the catalyst contains Ni, Co, Mn, Cr, V, Fe, Ti, or combinations thereof. Preferably, the catalyst contains 0.1 to 2 weight percent of the aforementioned metals. Regenerated catalysts, including regenerated ZSM5 or other catalysts from catalytic pyrolysis processes, can be used. The preferred temperature range is 120°C to 300°C, more preferably 150°C to 250°C, although higher temperatures can be used. The pressure preferably ranges from 1 atm to 20 atm (100 kPa to 2,000 kPa), with pressures of 1 to 5 atm (100 kPa to 500 kPa) being more preferred. Higher pressures can be used if higher olefin conversions are desired. In some preferred embodiments, the olefin-containing product stream is contacted with a liquid aromatics-containing stream that extracts olefins from the olefin-containing stream, and then alkylation of the olefins in the aromatics-containing stream is carried out simultaneously with or, more preferably, after the extraction step. Preferably, at least a portion of the aromatics used in the alkylation process, and more preferably all of the aromatics, are derived from the product stream of the catalytic pyrolysis reactor. The aromatics-to-olefins molar ratio is preferably greater than 1, more preferably greater than 5. The alkylation reaction can be carried out in a variety of reactor types, preferably a fixed bed reactor, and in some embodiments, the olefin is fed at multiple points along the length of the fixed bed reactor.

[0102] In some embodiments, the olefin-containing product stream undergoes both dimerization / oligomerization and alkylation. These processes can be carried out sequentially (in either order). Alternatively, the olefin-containing stream can be split and the dimerization / oligomerization and alkylation fractions separated.

[0103] In another embodiment, the olefin product stream is mixed with steam and passed over a hydrolysis catalyst effective for the hydrolysis of olefins to product alcohols at lower temperatures. The hydrolysis catalyst is a catalyst that catalyzes the reaction of water with olefins to form alcohols, such as an acid catalyst. The acid catalyst can be selected from acid catalysts known to those skilled in the art, including supported acids such as sulfated zirconia, sulfated silica, or sulfated alumina, or solid acids such as solid phosphoric acid, zeolites, pillared clay, or amorphous silica-alumina mixtures. Preferred catalysts are sulfated silica, sulfated alumina, sulfated zirconia, solid phosphoric acid, or acid-treated clay. The temperature in the catalyst holding zone is preferably 170°C to 400°C, more preferably 220°C to 300°C.

[0104] In another embodiment, the olefin-containing product stream is mixed with methanol (typically in the vapor phase) and passed over a catalyst to form ethers. The temperature in the ether-forming step is preferably 200°C to 400°C in the catalyst holding section. The catalyst is a catalyst that catalyzes the reaction of alcohols with olefins to form ethers, such as an acidic catalyst, preferably a solid acid catalyst. The acid catalyst can be selected from acid catalysts known to those skilled in the art, including supported acids such as sulfated zirconia, sulfated silica, or sulfated alumina, or solid acids such as solid phosphoric acid, zeolites, pillared clay, or amorphous silica-alumina mixtures. Preferred catalysts are sulfated silica, sulfated alumina, sulfated zirconia, solid phosphoric acid, or acid-treated clay. Ion exchange resins with acidic groups, such as sulfate, nitrate, phosphate, carboxylate, benzoate, or trifluoroacetate, attached to a polymer backbone, such as Amberlyst, can also be used. The temperature in the catalyst holding section is preferably 170°C to 400°C, more preferably 220°C to 300°C. The pressure for the reaction is preferably at least 1 atm (100 kPa), and in some embodiments, in the range of 1 to 50 atm (100 to 5,000 kPa). The molar ratio of alcohol to olefin is preferably in the range of 0.1 to 10, more preferably 0.5 to 5, and in some embodiments, 0.5 to 2.

[0105] Olefins can also be reacted with higher alcohols, such as ethanol, propanol (n-propanol, iso-propanol, or mixtures thereof), or mixtures of alcohols to form ethers. This reaction can be carried out in the presence of a catalyst and under the conditions described above for methanol. A more preferred temperature range is 100°C to 200°C. In addition to, or as an alternative to, the catalysts described above for methanol, a zeolite catalyst may be present in the reactor in which the ethers are produced. Examples of suitable zeolites include zeolite Y, zeolite X, ZSM-3, ZSM-5, ZSM-12, ZSM-20, ZSM-23, ZSM-35, ZSM-38, ZSM-50, MCM-22, and mixtures thereof.

[0106] In any of the processes described herein, the olefin-containing gas can be partially separated into different fractions for functionalization to remove non-reactive components or to purge excess material.

[0107] In another embodiment of the present invention, the aromatics stream recovered from the process may be separated and hydrogenated to produce a fuel blendstock, as described in WO2017136177 and WO2017136178, "Chemicals and Fuel Blendstocks by a Catalytic Fast Pyrolysis Process," which are incorporated herein by reference.

[0108] Integration with steam cracking When polyolefins are used as feedstocks for Plas-TCat, high yields of ethylene and propylene are produced, along with C4+ hydrocarbons, including BTX. Plas-TCat process facilities can be located adjacent to petroleum-based primary olefin production companies based on steam cracking technology. When both processes are co-located, they can share common downstream separation equipment, increasing efficiency and reducing operating and capital costs. The recovery and purification of light olefins from light paraffins and other hydrocarbons requires a complex series of distillation columns, cryogenic processing, and cleanup reactors, which creates high capital and operating costs. For this and other reasons, steam cracking facilities are typically the largest petrochemical units in existence to take advantage of economies of scale to lower unit production costs.

[0109] Co-location of the plastic catalytic pyrolysis (Plas-TCat) process with a steam cracking facility offers several advantages, among them: (1) single unit operation; (2) purge gas combustion can provide sufficient heat to carry out the endothermic pyrolysis reaction on the catalyst; (3) improved heat integration; (4) control of the regenerator temperature through the amount of purge gas in the regenerator feed; (5) reduced costs due to shared infrastructure such as product separation, gas compression, and product quenching; (6) flexible unit operation; (7) recycled olefins or other gaseous products can provide the fluidization gas required for the fluid catalytic cracker (FCC) unit or the Plas-TCat unit; (8) increased aromatics yield; and (9) more efficient olefin utilization.

[0110] Due to the economics of waste plastic collection, the quantity of suitable feedstock material, and the logistics of collection and transportation, the amount of light olefins from Plas-TCat will be much less than that produced from a typical modern steam cracking unit, likely putting the Plas-TCat unit at a disadvantage in terms of downstream economies of scale when operated in isolation. Integrating Plas-TCat into a steam cracker improves economics in a surprising way. For steam crackers that make pyrolysis gasoline (pyrolysis gas), a pyrolysis gasoline separation and hydrotreater can provide integration services for both the steam cracker pyrolysis gasoline and the C5+ BTX-rich liquid product of Plas-TCat.

[0111] In one embodiment of the process of the present invention, the process of polymer or plastic catalytic pyrolysis is integrated with a steam cracking facility, and the initial product stream or a portion thereof is combined with the steam cracker process stream for purification and upgrading in the steam cracking facility.

[0112] In one embodiment, waste heat from the steam cracker steam product can be used to provide heat to the catalytic pyrolysis reactor. The heat transferred from the high-temperature steam cracker steam to the Plas-TCat catalyst also contributes to quenching the steam cracker effluent, which helps avoid undesirable post-cracking reactions and improve product yields in the Plas-TCat process. The amount of light olefins provided by plastic waste recycling can be easily measured using flow meters and chemical analysis instruments, and therefore the mixture of virgin and recycled olefins can be accurately quantified. Accurate quantification of waste recycling products can provide additional revenue in the form of loans or subsidies for waste recycling.

[0113] The hydrogen produced by both steam cracking and Plas-TCat can be used for pyrolysis gasoline hydrogenation, hydrotreating, upgrading of other liquid products, or other processes. In some embodiments of the inventive process, the hydrogen from steam cracking or the hydrogen from catalytic pyrolysis, or some combination thereof, is used for hydrocracking of heavy materials or hydrotreating of product streams, or other processes within the facility.

[0114] Figure 6 shows a simplified general process flow diagram for a steam cracker reactor and downstream product recovery and separation procedures published on the internet by Toyo Engineering. Circles identified with alphabetical letters indicate specific flows and / or locations within the process procedure where integration between the Plas-TCat process and the steam cracker process can occur, as described below.

[0115] Location "A" is the primary quench heat exchanger for the steam cracker. This is a candidate location for including a catalytic heater. In this embodiment of the invention, the catalyst circulating within the Plas-TCat unit is heated by the steam cracker product gases and then used to drive the catalytic pyrolysis process. At the same time, the steam cracker hot gases are partially quenched.

[0116] Location "B" is the steam cracker quench tower. Depending on the steam cracker feed design, the steam cracker quench tower can be a direct water-cooled quench, a hot oil quench, or a combination hot oil and water quench, usually as two separate towers in series. In this embodiment of the invention, the hot Plas-TCat vapor product is introduced into the quench tower along with the steam cracker gas and vapor product because the two streams are chemically similar. The Plas-TCat gas is generally cooled more than the steam cracker gas, thereby providing some additional heat integration to the configuration.

[0117] Positions "C" and "E" are methane-containing streams. In one embodiment of the present invention, either of the methane-containing streams is used as a component of the fluidizing gas in the Plas-TCat reactor.

[0118] Position "D" is hydrogen, a by-product of both steam cracking and Plas-TCat. In one embodiment of the present invention, the hydrogen produced in steam cracking is used in several places in the process of the present invention, including acetylene hydrogenation, methylacetylene / propadiene hydrogenation, and hydrotreating of pyrolysis gasoline or other products to reduce their content of sulfur, nitrogen, oxygen, trienes, dienes, and styrene.

[0119] Position "F" is shown for three streams, including a relatively pure stream of ethane and propane, and a third stream consisting of C4 olefins and paraffins. All of these components are produced by steam cracking and the Plas-TCat process. In another embodiment of the invention, any of the streams, or any combination thereof, is recycled to the steam cracker to produce more ethylene and propylene. Optionally, a portion of any stream can be used for Plas-TCat fluidization gas. Recycling the C4-rich stream to Plas-TCat is expected to produce more BTX and light olefins.

[0120] Finally, position "G" is the combined pyrolysis gasoline and Plas-TCat BTX-rich naphtha. In another embodiment of the present invention, the combined pyrolysis gasoline and Plas-TCat BTX-rich naphtha are hydrotreated to improve their storage stability by reducing or eliminating the concentration of highly unsaturated compounds such as dienes, trienes, acetylenes, and vinyl aromatic compounds (e.g., styrene). Trace amounts of heteroatoms such as sulfur, nitrogen, chlorides, and oxygen can also be removed by hydrotreating. In some embodiments, the hydrotreated product is further separated and purified to produce polymer-grade benzene, toluene, p-xylene, or some combination thereof. Hydrotreating is required to reduce olefins and other contaminants to low levels suitable for polymer production or other upgrading processes. [Example]

[0121] The drop tube reactor comprises a quartz reactor tube (ACE Glass) containing a fused quartz frit (40-90 μm) in the center of the tube. Figure 7 shows the configuration of the drop tube reactor. A sample cell (10 mm outer diameter, 8 mm inner diameter, 25 mm length, quartz, manufactured by TGP) is used to contain the feedstock using two pieces of quartz wool (TGP). As illustrated in Figure 7, the sample cell is 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 are then assembled and installed on a fixed-bed reactor system. The bottom of the reactor is connected to a condenser (borosilicate) filled with perforated stainless steel packing (ACE Glass) immersed in an ice-water bath (0 °C). A heating mantle is applied between the bottom of the reactor and the top of the condenser to prevent any condensation in front of the condenser. The heating mantle was set to 210°C during the reaction.

[0122] In the reactor, a small sample of ZSM-5 catalyst (1.5 g) was placed on top of the quartz frit. The feedstock (100 mg for each run) was sealed in the sample cell with quartz wool. The catalyst / feedstock weight ratio was approximately 15. Before dropping the contents of the sample cell into the reactor, the catalyst was calcined at 550 °C for 20 min under an air flow of 100 mL / min (ramp rate = 12 °C / min). After calcination, the reactor was cooled to the reaction temperature (500 °C for plastics and 525 °C for biomass). During cooling, the condenser was filled with 10 mL of solvent (ethyl acetate for plastic conversion and 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 was dropped into the reactor by withdrawing the stopper rod to start the reaction.

[0123] A 10-minute holding period allowed the reaction to reach completion. The gas products, consisting primarily of permanent gases, as well as C1-C3 olefins and paraffins, were collected in a gas bag. The liquid products (mainly C 4+) was collected in the condenser. After the reaction, the temperature was increased to 650 °C without gas flow. The solid product, including coke and char remaining in the reactor, was then baked at 650 °C for 10 min under an air flow of 50 mL / min. During the bake, the gas product was collected in a second gas bag. An additional 3 mL of solvent was added to the condenser to extract any product remaining on top of the condenser. All of the 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. Lifting the packing revealed that a small amount of liquid had accumulated in the condenser. Therefore, the condenser with and without the liquid product was weighed to obtain the total amount of liquid product. Liquid samples were analyzed for hydrocarbons and oxygenates by GC-FID (Shimadzu 2010Plus gas chromatograph equipped with a flame ionization detector). Gas bag samples were analyzed using an Agilent GC 7890B gas chromatograph.

[0124] The results of the various feed runs are presented in Table 2. The product balance not accounted for in Table 2 includes water, inert solids, and trace components that are not easily recovered due to combustion.

[0125] A spreadsheet was developed to calculate the energy balance for the catalytic pyrolysis process, including heating of the feed and fluidization gas, and separation and purification of BTX. Assumptions used in the calculation include: 1.100 kg / hour of plastic is pyrolyzed in the process 2. Heat exchanger efficiency is 80% (heat recovery from flue gas and reactor effluent is 80%) 3. The air to the regenerator is 20% in excess of the stoichiometric amount needed to burn the coke (and gas, if necessary). 4. The heat loss in the regenerator is 2% of the regenerator heat load. 5. The catalyst to plastic ratio is 15 (1500 kg of catalyst in the reactor). 6. Carbon loading on the regenerator is assumed to be 15 wt%. 7. The catalytic pyrolysis yield of products is a linear combination of those listed in Table 2 for the feed mixture weighed by the mass of each component of the feed mixture. 8. The heat of combustion released in the regenerator is a linear combination of those listed in Table 3 for the appropriate mixture of coke and gas products in each example, weighed by the mass of each component of the feed mixture. 9. The heat of reaction required for the process is a linear combination of those listed in Table 4, scaled by the mass of each component of the feed mixture. 10. The heat capacity of the catalyst is 1.2 kJ / kg-T. 11. The heat capacity of a fluidizing gas is 1.0 kJ / kg-T. 12. The regenerator is operated at 670°C. 13. The heat capacity of the reactor effluent is 1.48 kJ / kg-T. 14. Catalytic pyrolysis is operated at 525°C. 15. The energy required to heat the feed and air for the regenerator, plus losses from the process and regenerator, is approximately 127,000 kJ.

[0126] Table 2. Products of catalytic pyrolysis of various materials over ZSM-5 catalyst in drop tube experiments. All values ​​are in weight percent.

[0127] [Table 2]

[0128] [Table 3]

[0129] [Table 4]

[0130] Examples 1 to 7 The minimum energy required for a catalytic pyrolysis process includes the energy of reaction, the energy to heat the feed, the energy lost from the process, and the energy required for product separation and purification. For Example 1, when 42.8 kg of polyethylene is catalytically reacted, the energy required is 128,000 kJ and 0.38 kg of coke is produced. When 57.2 kg of PET is catalytically pyrolyzed, the energy required is 103,000 kJ and 10.16 kg of coke is produced. Including the 127,000 kJ required for heating and the energy lost from the process, the total minimum energy required is (128,000 + 103,000 + 127,000) kJ = 358,000 kJ. Combustion of the coke produced generates the 358,000 kJ necessary for the process to be self-sufficient, i.e., it does not require energy input from external sources such as fossil fuels.

[0131] As shown, the amount of high coke-forming material that would need to be mixed with PE, PP, and PS to meet the total minimum energy required for the process was calculated for each of the polymers with PET (Examples 1, 4, and 5), biomass (Examples 2 and 6), or tires (Examples 3 and 7) as the high coke-forming material for PE, PP, and PS.

[0132] The results in Table 5 show that by blending high coke-forming materials with polymers, an overall energy-balanced process can be achieved when the coke is burned to provide the energy for the process. The fraction of high coke-forming material in Table 5 is the minimum amount of that material needed to provide the minimum energy required for the process when the coke is burned; the higher the fraction of high coke-forming material in the blend, the more excess energy will be available for other process operations or for export from the plant.

[0133] Table 5 presents the calculated amounts of high coke-forming materials required for heat from the combustion of coke and char to balance the heat required for processes to convert various mixtures containing low coke-forming polymers into valuable aromatics, olefins, and other products.

[0134] [Table 5]

[0135] Examples 8 to 14 The calculations of Examples 1-7 were repeated, burning the coke and the CO and H2 by-products to provide the energy required for the conversion of the mixture. The results are presented in Table 6.

[0136] The results in Table 6 show that it is possible to formulate mixtures containing various high coke-forming materials with various polymers as feed to a catalytic pyrolysis process without requiring an external energy source, i.e., the energy produced in the combustion of the coke and H2 and CO by-products is at least equal to the minimum energy required for the catalytic pyrolysis process. The fractions of high coke-forming material in Table 6 are the minimum amount of high coke-forming material needed to balance the energy requirements of the process; the higher the fraction of coke-forming material in the mixture, the greater the excess energy available for other process operations or plant export.

[0137] Table 6 presents the calculated amounts of high coke-forming feed material required when the heat of combustion from the coke and by-product gases H and CO is used to balance the heat required for the process to convert various low coke-forming polymers into aromatics, olefins, and other useful products.

[0138] [Table 6]

[0139] Examples 15 to 19 The calculations of the previous example were repeated, except that the energy required for the catalytic pyrolysis process was provided by the combustion of the coke produced in the process and by the gas mixture recovered after removing the C5+ products, i.e., the fraction of gas containing C2-C4 olefins and paraffins, CH4, CO, CO2, and H2. The fractions of gas needed to balance the energy requirements are presented in Table 7.

[0140] The results in Table 7 show that for catalytic pyrolysis of polymers, adding high coke-forming materials to the feed can balance the energy requirements of the process when the coke and at least a fraction of the gaseous by-products are burned to provide energy for the catalytic pyrolysis process. The gaseous by-product fractions presented in Table 7 are the minimum amounts required to equal the minimum energy required for the catalytic pyrolysis process when gases are burned in addition to the coke; the higher the fraction of high coke-forming materials in the mixture, the greater the excess energy available for other process operations or export from the plant.

[0141] Table 7 presents the calculated fraction of various low coke-forming polymers and by-product gas mixtures that need to be combusted along with all of the coke formed in the process to provide the energy needed for the process to convert mixtures of low and high coke-forming materials into aromatics, olefins, and other useful products.

[0142] [Table 7]

[0143] The results presented in Examples 1-19 demonstrate that the minimum energy requirements of a process for catalytically pyrolyzing plastics to produce useful materials such as BTX and olefins can be met by the energy generated by combustion of the coke, or some fraction of the coke and by-product gases, when a coke-forming material is fed along with the polymer. These examples represent only a few combinations of coke-forming materials and polymers that can be used to produce an energy-balanced process; one skilled in the art can readily apply the principles of this invention to any mixture of feedstocks encountered.

[0144] Examples 20 to 22 A computational model was constructed in Excel to calculate the buildup of contaminants on the catalyst as a function of the fraction of coke-forming material in an otherwise contaminant-free polyethylene feed, the level of contaminants in the coke-forming material, and the rate of catalyst exchange. The model calculates the steady state of contaminants on the catalyst that is reached in the continuous operation of a catalytic pyrolysis process in a fluidized bed.

[0145] Example 20 Figure 8 shows the calculated steady-state loading of inert contaminants (e.g., silica) on the catalyst as a function of catalyst exchange rate when tires containing 7% inert contaminants are fed as coke-forming feed with polyethylene in a catalytic pyrolysis process. The fraction of tire contained in the feed was 2.5 wt%, 5 wt%, 10 wt%, and 15 wt%. The results presented in Figure 8 can be used to optimize the process with respect to catalyst cost, catalyst tolerance to contaminants, catalyst make-up rate, and feed material availability and cost.

[0146] Example 21 Figure 9 shows the calculated steady-state loading of inert contaminants on the catalyst as a function of catalyst exchange rate when biomass containing 0.4% inert contaminants (e.g., silica) is fed as a coke-forming feed with polyethylene in a catalytic pyrolysis process. The mass fraction of biomass contained in the feed is 20 wt%, 40 wt%, 60 wt%, and 80 wt%. The results presented in Figure 9 can be used to optimize the process with respect to catalyst cost, catalyst tolerance to contaminants, catalyst make-up rate, and feed material availability and cost.

[0147] Example 22 10 shows the calculated steady-state loading of inert contaminants on the catalyst as a function of catalyst exchange rate when tires containing 7% inert contaminants (e.g., silica) are pre-pyrolyzed in a separate process to remove 99% of the inert contaminants and steam is fed with polyethylene in a catalytic pyrolysis process. The fraction of tire that produced steam is 2.5%, 5%, 10%, and 15% by weight of the feed mixture with polyethylene. The calculated steady-state loading of inert contaminants is much lower than in Example 20, where virgin tires were co-fed with polyethylene, and comparable to the loading from the co-feed experiment with biomass as a co-feed in Example 21. This demonstrates the benefits of catalyst use and cost when tires are pre-pyrolyzed in the process. Pre-pyrolysis produces carbon-rich solids derived from the tires, which contain the majority of the inert contaminants, and the carbon black that was a component of the tires. These carbon-rich solids can be combusted to provide at least a portion of the energy required for the catalytic pyrolysis process. The steam from pre-pyrolysis, when fed to the catalytic pyrolysis, improves the yield of aromatics, olefins, and other valuable components in the catalytic pyrolysis process. The results presented in Figure 10 can be used to optimize the process with respect to catalyst cost, catalyst tolerance to contaminants, feed pretreatment cost, pollutant removal efficiency, process complexity, catalyst make-up rate, and feed material availability and cost.

Claims

1. 1. A method for catalytically pyrolyzing a mixed feed of materials, comprising: providing a first stream comprising a polymer; adding coke-forming material to said first stream to form a mixed feed of materials; adding the mixed feed of materials to a fluidized bed reactor; pyrolyzing the mixed feed in the presence of a solid catalyst in the fluidized bed reactor to produce a fluid product stream and a coke-bearing spent catalyst, wherein at least 95% of the carbon in the mixed feed is converted to coke and volatile products; transferring at least a portion of the spent catalyst with the coke to a regenerator where the coke reacts with oxygen to form a high-temperature regenerated catalyst, and returning at least a portion of the high-temperature regenerated catalyst to the fluidized bed reactor, wherein heat from the high-temperature regenerated catalyst provides energy for a pyrolysis step of the mixed feed; (a) heat from the reaction of the coke with oxygen provides at least 90% of the energy required for the pyrolysis step of the mixed feed; providing said first stream has properties such that when a stream consisting solely of said first stream undergoes said pyrolysis step and all of said coke-bearing spent catalyst is transferred to said regenerator where said coke is combusted with oxygen to form said hot regenerated catalyst and hot combustion gases, and all of said hot regenerated catalyst is returned to said fluidized bed reactor, said heat from said hot regenerated catalyst providing energy for said pyrolysis step, said heat provided by said combustion of said coke, including heat of said catalyst and heat recovered from said combustion gases, provides energy that is less than the minimum energy required for said pyrolysis step of said mixed feed, wherein at least 95% of the carbon in said first stream is converted to coke and volatile products; or (b) heat from the reaction of the coke with oxygen and combustion of a portion of the volatile products provides at least 90% of the energy for the pyrolysis step; providing the first stream has properties such that when a stream consisting solely of the first stream undergoes the pyrolysis step, and all of the spent catalyst with coke and a portion of the volatile products are transferred to the regenerator where the coke and the portion of the volatile products are combusted with oxygen to form the hot regenerated catalyst and hot combustion gases, and all of the hot regenerated catalyst is returned to the fluidized bed reactor, and the heat from the hot regenerated catalyst provides energy for the pyrolysis step, the heat provided by the combustion of the coke, including the heat of the catalyst and the heat recovered from the combustion gases, provides energy that is less than the minimum energy required for a catalytic pyrolysis process in which at least 95% of the carbon in the first stream is converted to coke and volatile products; the method, wherein the addition of the coke-forming material to the mixed feed results in sufficient coke to provide at least the minimum energy required for a catalytic pyrolysis process in which at least 95% of the carbon in the mixed feed is converted to coke and volatile products.

2. 10. The method of claim 1, wherein heat from reaction of coke and a portion of the volatile products provides at least 90% of the energy for the pyrolysis step, and wherein the portion of the volatile products that is combusted comprises a CO and H enriched stream separated from the volatile products.

3. 2. The method of claim 1, wherein heat from reaction of coke and a portion of the volatile products provides at least 90% of the energy for the pyrolysis step, and wherein the portion of the volatile products that is combusted comprises a fraction of a gas mixture recovered after removing C5+ products from the volatile products.

4. The mixed feed material may be selected from the group consisting of biomass, polyethylene (PE), polypropylene (PP), polyacetylene, polybutylene, polyolefin, polyethylene terephthalate (PET), polybutylene terephthalate, copolyester, polyester, polycarbonate, polyurethane, polyamide, polystyrene (PS), polyacetal, epoxy resin, polycyanurate, polyacrylic acid, polyurea, vinyl ester resin, polyacrylonitrile, polyvinyl alcohol, polyvinyl chloride (PVC), polyvinyl acetate, nylon, copolymers such as ethylene-propylene copolymer (EPDM), acrylonitrile-butadiene-styrene (ABS), nylon, and the like.

4. The method of any one of claims 1 to 3, wherein the polymeric material is selected from the group consisting of: styrene rubber, natural and synthetic rubber, tires, styrene-butadiene, styrene-acrylonitrile, styrene-isoprene, styrene-maleic anhydride, ethylene-vinyl acetate, nylon 12 / 6 / 66, polymer composites, plastic alloys, and materials separated from waste streams such as polymers or plastics dissolved in solvents, post-consumer recycled polymeric materials, municipal solid waste, black liquor, or wood waste, whether obtained from a polymer or plastic manufacturing process as waste or as disposal material, or some combination thereof.

5. 5. The method of any one of claims 1 to 4, wherein heat from the combustion of coke provides at least 90% of the energy required for the pyrolysis step.

6. 6. The method of any one of claims 1 to 5, wherein the polymer is selected from polyethylene, polypropylene and polystyrene, or mixtures thereof, and the coke-forming material is selected from biomass, polyethylene terephthalate, tires, cellulose, cellulose acetate, cotton clothing and nylon, or mixtures thereof.

7. 7. The process of any one of claims 1 to 6, wherein the reaction is carried out in a fluidized bed, circulating bed, bubbling bed or riser reactor at an operating temperature in the range of from 300°C to 1000°C, or from 400°C to 650°C, or from 450°C to 600°C, or from 500°C to 575°C.

8. 8. The process of any one of claims 1 to 7, wherein a stream enriched in ethylene or propylene, or both, is separated from the volatile products.

9. 9. The process according to any one of claims 1 to 8, wherein the volatile products comprise at least 10% by weight of olefins.

10. 10. The process of any one of claims 1 to 9, wherein a stream comprising C5+ products is separated from the volatile products.

11. 11. The method of any one of claims 1 to 10, wherein a stream concentrated in benzene, toluene, xylene or some combination thereof is separated from the volatile products.

12. 12. The process of any one of claims 1 to 11, wherein the mass yield of BTX is at least 10%, based on the mass in the polymer feed.

13. 13. The method of any one of claims 1 to 12, wherein the mixed feed comprises 5 to 98% by mass of PE, PP, PS, or mixtures thereof, and the remainder of the mixed feed comprises at least 95% by mass of high coke-forming materials.

14. 14. The method of any one of claims 1 to 13, wherein the mixed feed comprises 5 to 98% by mass of PE, PP, PS, or mixtures thereof; and 2 to 60% by mass of high coke forming materials, or 20 to 60% by mass of biomass, or 2 to 55% by mass of tire polymers, and is free of contaminants by mass.

15. 1. A method for catalytically pyrolyzing a mixed feed of materials, comprising: adding a first stream comprising a polymer into a fluidized bed reactor; pyrolyzing the polymer in the presence of a solid catalyst in the fluidized bed reactor to produce a fluid product stream and spent catalyst having coke, wherein at least 95% of the carbon in the mixed feed is converted to coke and volatile products; transferring at least a portion of the spent catalyst having the coke to a regenerator where the coke reacts with oxygen to form a high-temperature regenerated catalyst, and returning at least a portion of the high-temperature regenerated catalyst to the fluidized bed reactor, wherein heat from the high-temperature regenerated catalyst provides energy for a pyrolysis step; the first stream has properties such that when a stream consisting solely of the first stream undergoes the pyrolysis step and all of the spent catalyst with coke is transferred to the regenerator where the coke is burned with oxygen to form the hot regenerated catalyst and hot combustion gases, and all of the hot regenerated catalyst is returned to the fluidized bed reactor, and the heat from the hot regenerated catalyst provides energy for the pyrolysis step, the heat provided by the combustion of the coke, including the heat of the catalyst and the heat recovered from the combustion gases, provides less energy than the minimum energy required for a catalytic pyrolysis process in which at least 95% of the carbon in the first stream is converted to coke and volatile products, and an amount of oxygen is introduced into the first stream such that there is sufficient energy to convert at least 95% of the carbon in the first stream to coke and volatile products.

16. 16. The method of claim 15, wherein the amount of oxygen introduced into the first stream is between 0.6% and 10% by weight of the mass of the first stream.

17. 17. The method of claim 15 or 16, wherein the oxygen is introduced by the addition of air or O2 as a component of the fluidizing fluid, or in a gas injected with the polymer, or by separate direct injection into the fluidized bed reactor, or by some combination thereof.

18. The method of any one of claims 15 to 17, wherein the catalyst is a zeolite.

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