WO2023178132A1 - Recovery of valuable chemical products from recycle content pyrolysis oil - Google Patents

Recovery of valuable chemical products from recycle content pyrolysis oil Download PDF

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Publication number
WO2023178132A1
WO2023178132A1 PCT/US2023/064372 US2023064372W WO2023178132A1 WO 2023178132 A1 WO2023178132 A1 WO 2023178132A1 US 2023064372 W US2023064372 W US 2023064372W WO 2023178132 A1 WO2023178132 A1 WO 2023178132A1
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WO
WIPO (PCT)
Prior art keywords
stream
pyrolysis
pyrolysis oil
diolefins
weight percent
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PCT/US2023/064372
Other languages
French (fr)
Inventor
David Eugene SLIVENSKY
Daryl Bitting
Xianchun Wu
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Eastman Chemical Company
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Publication date
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Publication of WO2023178132A1 publication Critical patent/WO2023178132A1/en

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    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10GCRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G1/00Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
    • C10G1/10Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal from rubber or rubber waste
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10BDESTRUCTIVE DISTILLATION OF CARBONACEOUS MATERIALS FOR PRODUCTION OF GAS, COKE, TAR, OR SIMILAR MATERIALS
    • C10B53/00Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form
    • C10B53/07Destructive distillation, specially adapted for particular solid raw materials or solid raw materials in special form of solid raw materials consisting of synthetic polymeric materials, e.g. tyres
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10GCRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G1/00Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
    • C10G1/002Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal in combination with oil conversion- or refining processes
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10GCRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G21/00Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10GCRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G55/00Treatment of hydrocarbon oils, in the absence of hydrogen, by at least one refining process and at least one cracking process
    • C10G55/02Treatment of hydrocarbon oils, in the absence of hydrogen, by at least one refining process and at least one cracking process plural serial stages only
    • C10G55/04Treatment of hydrocarbon oils, in the absence of hydrogen, by at least one refining process and at least one cracking process plural serial stages only including at least one thermal cracking step
    • CCHEMISTRY; METALLURGY
    • C10PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
    • C10GCRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
    • C10G9/00Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils

Definitions

  • Waste plastic pyrolysis plays a part in a variety of chemical recycling technologies.
  • the pyrolysis of waste plastic produces heavy components (e.g., waxes, tar, and char), as well as recycle content pyrolysis oil (r-pyoil) and recycle content pyrolysis gas (r-pygas).
  • r-pyoil recycle content pyrolysis oil
  • r-pygas recycle content pyrolysis gas
  • the present technology concerns a chemical recycling process.
  • the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis oil stream; (b) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; and (c) introducing at least a portion of the raffinate stream into a cracker furnace.
  • the present technology concerns a chemical recycling process.
  • the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent; (b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream; (c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; (d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed; (e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; (f) compressing at least a portion of the cracked product in at least one compressor to form a compressed product; and (g) separating at least one hydrocarbon from the compressed product to
  • the present technology concerns a chemical recycling process.
  • the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent; (b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream; (c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; (d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed; (e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; and (f) subjecting at least a portion of the extract stream to a chemical process so as to synthe
  • FIG. 1 is a block flow diagram illustrating the main steps of a process and facility for chemically recycling waste plastic and recovering desirable recycle content products from the pyrolysis effluent according to embodiments of the present technology
  • FIG. 2 is an exemplary depiction of a solvent extraction process and facility for recovering aromatics and/or diolefins from the pyrolysis oil stream;
  • FIG. 3 is an exemplary depiction of an extractive distillation process and facility for recovering aromatics and/or diolefins from the pyrolysis oil stream.
  • FIG. 1 depicts an exemplary chemical recycling facility 10 comprising a pyrolysis reactor 12 and a cracking facility comprising a cracker furnace 14, a quench system 16, a compression system 18, and a separator 20.
  • the chemical recycling facility 10 may also contain a waste plastic source 22 and a condenser 24 for separating the pyrolysis effluent into a pyrolysis oil stream and a pyrolysis gas stream.
  • the chemical recycling facility 10 described herein is able to recover a number of valuable recycle content products from the pyrolysis effluent, prior to downstream treatment in a cracking facility. As depicted in FIG.
  • FIG. 1 depicts one exemplary embodiment of the present technology. Certain features depicted in FIG. 1 may be omitted and/or additional features described elsewhere herein may be added to the system depicted in FIG. 1 . The various process steps are described below in greater detail.
  • FIG. 1 the main steps of a process for chemically recycling waste plastic in a chemical recycling facility 10 are shown.
  • Chemical recycling processes and facilities as described herein may be used to convert waste plastic to recycle content products or chemical intermediates used to form a variety of end use materials.
  • the waste plastic fed to the chemical recycling facility/process can be mixed plastic waste (MPW), presorted waste plastic, and/or pre-processed waste plastic.
  • MPW mixed plastic waste
  • presorted waste plastic presorted waste plastic
  • pre-processed waste plastic pre-processed waste plastic.
  • the waste plastic feed stream 32 may be derived from the waste plastic source 22, which may include a waste plastic preprocessing facility.
  • the chemical recycling facility 10 may be a commercialscale facility capable of processing significant volumes of mixed plastic waste.
  • commercial scale facility refers to a facility having an average annual feed rate of at least 500 pounds per hour, averaged over one year.
  • two or more of the facilities shown in FIG. 1 such as the pyrolysis facility (e.g., the pyrolysis reactor 12, the waste plastic source 22, the condenser 24, and the separator 26) and the cracking facility (e.g., the cracker furnace 14, the quench system 16, the compressor system 18, and the separator 20) may be co-located with one another.
  • the term “co-located” refers to facilities in which at least a portion of the process streams and/or supporting equipment or services are shared between the two facilities.
  • the facilities may meet at least one of the following criteria (i) through (v): (i) the facilities share at least one non-residential utility service; (ii) the facilities share at least one service group; (iii) the facilities are owned and/or operated by parties that share at least one property boundary; (iv) the facilities are connected by at least one conduit configured to carry at least one process material (e.g., solid, liquid and/or gas fed to, used by, or generated in a facility) from one facility to another; and (v) the facilities are within 40, within 35, within 30, within 20, within 15, within 12, within 10, within 8, within 5, within 2, or within 1 mile of one another, measured from their geographical center. At least one, at least two, at least three, at least four, or all of the above statements (i) through (v) may be true.
  • process material e.g., solid, liquid and/or gas fed to, used by, or generated in a facility
  • suitable utility services include, but are not limited to, steam systems (co-generation and distribution systems), cooling water systems, heat transfer fluid systems, plant or instrument air systems, nitrogen systems, hydrogen systems, non-residential electrical generation and distribution, including distribution above 8000V, non- residential wastewater/sewer systems, storage facilities, transport lines, flare systems, and combinations thereof.
  • examples of service groups and facilities include, but are not limited to, emergency services personnel (fire and/or medical), a third- party vendor, a state or local government oversight group, and combinations thereof.
  • Government oversight groups can include, for example, regulatory or environmental agencies, as well as municipal and taxation agencies at the city, county, and state level.
  • the boundary may be, for example, a fence line, a property line, a gate, or common boundaries with at least one boundary of a third-party owned land or facility.
  • the conduit may be a fluid conduit that carries a gas, a liquid, a solid/liquid mixture (e.g., slurry), a solid/gas mixture (e.g., pneumatic conveyance), a solid/liquid/gas mixture, or a solid (e.g., belt conveyance).
  • a gas e.g., a liquid
  • a solid/liquid mixture e.g., slurry
  • a solid/gas mixture e.g., pneumatic conveyance
  • a solid/liquid/gas mixture e.g., belt conveyance
  • two units may share one or more conduits selected from the above list.
  • a stream of waste plastic which can be mixed plastic waste (MPW) may be introduced into the chemical recycling facility 10 from the waste plastic source 22.
  • MPW mixed plastic waste
  • the terms “waste plastic” and “plastic waste” refer to used, scrap, and/or discarded plastic materials, such as plastic materials typically sent to a landfill.
  • the waste plastic stream 32 fed to the chemical recycling facility 10 may include unprocessed or partially processed waste plastic.
  • unprocessed waste plastic means waste plastic that has not be subjected to any automated or mechanized sorting, washing, or comminuting. Examples of unprocessed waste plastic include waste plastic collected from household curbside plastic recycling bins or shared community plastic recycling containers.
  • Partially processed waste plastics may originate from, for example, municipal recycling facilities (MRFs) or reclaimers.
  • the waste plastic may comprise at least one of post-industrial (or pre-consumer) plastic and/or post-consumer plastic.
  • the mixed waste plastic includes at least two distinct types of plastic.
  • all or a portion of the MPW in the waste plastic stream 32 can originate from a municipal recycling facility (MRF).
  • MRF municipal recycling facility
  • all or a portion of the MPW in the waste plastic stream 32 can originate from a reclaimer facility.
  • suitable waste plastics can include, but are not limited to, polyolefins (PO), aromatic and aliphatic polyesters, polyvinyl chloride (PVC), polystyrene, cellulose esters, polytetrafluoroethylene, acrylobutadienestyrene (ABS), cellulosics, epoxides, polyamides, phenolic resins, polyacetal, polycarbonates, polyphenylene-based alloys, poly(methyl methacrylate), styrene-containing polymers, polyurethane, vinyl-based polymers, styrene acrylonitrile, and urea-containing polymers and melamines.
  • PO polyolefins
  • PVC polyvinyl chloride
  • ABS acrylobutadienestyrene
  • cellulosics epoxides
  • polyamides polyamides
  • phenolic resins polyacetal
  • polycarbonates polyphenylene-based alloys
  • Examples of specific polyolefins may include linear low-density polyethylene (LLDPE), low density polyethylene (LDPE), polymethylpentene, polybutene-1 , high density polyethylene (HDPE), atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, crosslinked polyethylene, amorphous polyolefins, and the copolymers of any one of the aforementioned polyolefins.
  • LLDPE linear low-density polyethylene
  • LDPE low density polyethylene
  • HDPE high density polyethylene
  • atactic polypropylene isotactic polypropylene
  • syndiotactic polypropylene syndiotactic polypropylene
  • crosslinked polyethylene amorphous polyolefins
  • amorphous polyolefins amorphous polyolefins
  • polyesters can include those having repeating aromatic or cyclic units such as those containing a repeating terephthalate, isophthalate, or naphthalate units such as PET, modified PET, and PEN, or those containing repeating furanate repeating units.
  • PET polyethylene terephthalate
  • polyethylene terephthalate refers to a homopolymer of polyethylene terephthalate, or to a polyethylene terephthalate modified with one or more acid and/or glycol modifiers and/or containing residues or moieties of other than ethylene glycol and terephthalic acid, such as isophthalic acid, 1 ,4- cyclohexanedicarboxylic acid, diethylene glycol, 2,2,4,4-tetramethyl-1 ,3- cyclobutanediol (TMCD), cyclohexanedimethanol (CHDM), propylene glycol, isosorbide, 1 ,4-butanediol, 1 ,3-propane diol, and/or neopentyl glycol (NPG).
  • isophthalic acid 1 ,4- cyclohexanedicarboxylic acid
  • diethylene glycol 2,2,4,4-tetramethyl-1 ,
  • the waste plastic stream 32 comprises at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent of one or more polyolefins, based on the total weight of the stream.
  • the waste plastic stream 32 comprises not more than 99.9, not more than 99, not more than 97, not more than 92, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, or not more than 5 weight percent of one or more polyolefins, based on the total weight of the stream.
  • the waste plastic stream 32 comprises not more than 20, not more than 15, not more than 12, not more than 10, not more than 8, not more than 6, not more than 5, not more than 4, not more than 3, not more than 2, or not more than 1 weight percent of polyesters, based on the total weight of the stream.
  • the waste plastic stream 32 comprises not more than 20, not more than 15, not more than 12, not more than 10, not more than 8, not more than 6, not more than 5, not more than 4, not more than 3, not more than 2, or not more than 1 weight percent of biowaste materials, based on the total weight of the stream.
  • biowaste refers to material derived from living organisms or of organic origin. Exemplary biowaste materials include, but are not limited to, cotton, wood, saw dust, food scraps, animals and animal parts, plants and plant parts, and manure.
  • the waste plastic stream 32 can include not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.75, or not more than 0.5 weight percent of polyvinyl chloride (PVC), based on the total weight of the stream.
  • PVC polyvinyl chloride
  • unprocessed, partially processed, and/or processed waste plastic such as mixed plastic waste (MPW) may first be introduced into the chemical recycling facility 10 via the waste plastic stream 32 from the waste plastic source 22.
  • the waste plastic source 22 may include an optional preprocessing facility that can prepare the waste plastic feedstock for the downstream recycling processes. While in the optional preprocessing facility, the waste plastic feedstock may undergo one or more preprocessing steps to prepare it for chemical recycling.
  • preprocessing facility refers to a facility that includes all equipment, lines, and controls necessary to carry out the preprocessing of waste plastic.
  • Preprocessing facilities as described herein may employ any suitable method for carrying out the preparation of waste plastic for chemical recycling using one or more of following steps, which are described in further detail below.
  • the waste plastic source 22 does not contain a preprocessing facility and the waste plastic stream 32 is not subjected to any preprocessing before any of the downstream chemical recycling steps described herein.
  • the preprocessing facility of the waste plastic source 22 may include at least one separation step or zone.
  • the separation step or zone may be configured to separate the waste plastic stream 32 into two or more streams enriched in certain types of plastics. Such separation is particularly advantageous when the waste plastic fed to the chemical recycling facility 10 is MWP.
  • any suitable type of separation device, system, or facility may be employed to separate the waste plastic into two or more streams enriched in certain types of plastics such as, for example, a PET-enriched stream and a PO-enriched stream.
  • suitable types of separation include mechanical separation and density separation, which may include sink-float separation and/or centrifugal density separation.
  • sink-float separation refers to a density separation process where the separation of materials is primarily caused by floating or sinking in a selected liquid medium
  • centrifugal density separation refers to a density separation process where the separation of materials is primarily caused by centrifugal forces.
  • the waste plastic stream 32 may be introduced into one or more downstream processing facilities (or undergo one or more downstream processing steps) within the chemical recycling facility 10.
  • at least a portion of the waste plastic stream 32 may be directly or indirectly introduced into a plastic liquification zone within the waste plastic source 22 or outside of it. Additional details of each step, as well as the general integration of each of these steps or facilities with one or more of the others according to one or more embodiments of the present technology are discussed in further detail below.
  • the waste plastic stream 32 may be introduced into a plastic liquification zone prior to being introduced into the pyrolysis reactor 12.
  • the plastic liquification zone may be present in the waste plastic source 22 or it may be positioned separately and independently.
  • the term “liquification” zone refers to a chemical processing zone or step in which at least a portion of the incoming plastic is liquefied.
  • the step of liquefying plastic can include chemical liquification, physical liquification, or combinations thereof.
  • Exemplary methods of liquefying the plastic introduced in the liquification zone can include: (i) heating/melting; (ii) dissolving in a solvent; (iii) depolymerizing; (iv) plasticizing; and combinations thereof. Additionally, one or more of options (i) through (iv) may also be accompanied by the addition of a blending or liquification agent to help facilitate the liquification (reduction of viscosity) of the polymer material. As such, a variety of rheology modification agents (e.g., solvents, depolymerization agents, plasticizers, and blending agents) can be used the enhance the flow and/or dispersibility of the liquified waste plastic.
  • rheology modification agents e.g., solvents, depolymerization agents, plasticizers, and blending agents
  • the reduction in viscosity can be facilitated by heating (e.g., addition of steam directly or indirectly contacting the plastic), while, in other cases, it can be facilitated by combining the plastic with a solvent capable of dissolving it.
  • suitable solvents can include, but are not limited to, alcohols such as methanol or ethanol, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, cyclohexanedimethanol, glycerin, pyrolysis oil, motor oil, and water.
  • This dissolution solvent can be added directly to the liquification vessel in the liquification zone, or it can be previously combined with one or more streams fed to the liquification zone, including the waste plastic stream 32.
  • the dissolution solvent can comprise a stream withdrawn from one or more other facilities within the chemical recycling facility 10.
  • the solvent can comprise a stream withdrawn from the pyrolysis reactor 12 and/or the separation zone.
  • the dissolution solvent can be or comprise pyrolysis oil.
  • the waste plastic can be depolymerized such that, for example, the number average chain length of the plastic is reduced by contact with a depolymerization agent.
  • a depolymerization agent can include an organic acid (e.g., acetic acid, citric acid, butyric acid, formic acid, lactic acid, oleic acid, oxalic, stearic acid, tartaric acid, and/or uric acid) or inorganic acid such as sulfuric acid (for polyolefins).
  • the depolymerization agent may reduce the melting point and/or viscosity of the polymer by reducing its number average chain length.
  • Plasticizers for polyethylene include, for example, dioctyl phthalate, dioctyl terephthalate, glyceryl tribenzoate, polyethylene glycol having molecular weight of up to 8,000 Daltons, sunflower oil, paraffin wax having molecular weight from 400 to 1 ,000 Daltons, paraffinic oil, mineral oil, glycerin, EPDM, and EVA.
  • Plasticizers for polypropylene include, for example, dioctyl sebacate, paraffinic oil, isooctyl tallate, plasticizing oil (Drakeol 34), naphthenic and aromatic processing oils, and glycerin.
  • Plasticizers for polyesters include, for example, polyalkylene ethers (e.g., polyethylene glycol, polytetramethylene glycol, polypropylene glycol or their mixtures) having molecular weight in the range from 400 to 1500 Daltons, glyceryl monostearate, octyl epoxy soyate, epoxidized soybean oil, epoxy tallate, epoxidized linseed oil, polyhydroxyalkanoate, glycols (e.g., ethylene glycol, pentamethylene glycol, hexamethylene glycol, etc.), phthalates, terephthalates, trimellitate, and polyethylene glycol di-(2-ethylhexoate).
  • polyalkylene ethers e.g., polyethylene glycol, polytetramethylene glycol, polypropylene glycol or their mixtures
  • polyhydroxyalkanoate e.g., ethylene glycol, pentamethylene glycol, hexamethylene glycol, etc
  • the plasticizer may be present in an amount of at least 0.1 , at least 0.5, at least 1 , at least 2, or at least 5 weight percent and/or not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent, based on the total weight of the waste plastic stream 32, or it can be in a range of from 0.1 to 10 weight percent, 0.5 to 8 weight percent, or 1 to 5 weight percent, based on the total weight of the waste plastic stream 32.
  • one or more of the methods of liquefying the waste plastic stream 32 can also include adding at least one blending agent to the plastic stream before, during, or after the liquification process in the liquification zone.
  • Such blending agents may include for example, emulsifiers and/or surfactants, and may serve to more fully blend the liquified plastic into a single phase, particularly when differences in densities between the plastic components of a mixed plastic stream result in multiple liquid or semi-liquid phases.
  • the blending agent may be present in an amount of at least 0.1 , at least 0.5, at least 1 , at least 2, or at least 5 weight percent and/or not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent, based on the total weight of the waste plastic stream 32, or it can be in a range of from 0.1 to 10 weight percent, 0.5 to 8 weight percent, or 1 to 5 weight percent, based on the total weight of the waste plastic stream 32.
  • a portion of the pyrolysis oil stream withdrawn from the condenser 24 can be combined with the waste plastic stream 32 to form a liquified plastic.
  • all or a portion of the pyrolysis oil stream may be combined with the waste plastic stream 32 prior to introduction into the liquification zone, or after the waste plastic stream 32 enters the liquification vessel within the liquification zone.
  • the liquified (or reduced viscosity) plastic stream withdrawn from the liquification zone can include at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent of one or more polyolefins, based on the total weight of the stream, or the amount of poly
  • the liquified plastic stream exiting the liquification zone can have a viscosity of less than 3,000, less than 2,500, less than 2,000, less than 1 ,500, less than 1 ,000, less than 800, less than 750, less than 700, less than 650, less than 600, less than 550, less than 500, less than 450, less than 400, less than 350, less than 300, less than 250, less than 150, less than 100, less than 75, less than 50, less than 25, less than 10, less than 5, or less than 1 poise, as measured using a Brookfield R/S rheometer with a V80-40 vane spindle operating at a shear rate of 10 rad/s and a temperature of 350°C.
  • the liquification zone may comprise at least one melt tank and/or at least one extruder to facilitate the plastic liquification. Additionally, in certain embodiments, the liquification zone may also contain at least one stripping column and at least one disengagement vessel to facilitate the removal of halogenated compounds that may be formed in the melt tank and/or the extruder.
  • the melt tank and/or the extruder may receive the waste plastic feed stream and heat the waste plastic via heating mechanisms in the melt tank and/or via the extrusion process in the extruder.
  • the melt tank can include one or more continuously stirred tanks.
  • one or more rheology modification agents e.g., solvents, depolymerization agents, plasticizers, and blending agents
  • such rheology modification agents can be added to and/or mixed with the waste plastic stream 32 in or prior to introduction into the melt tank.
  • the interior space of the liquification vessel, where the plastic is heated is maintained at a temperature of at least 200, at least 210, at least 220, at least 230, at least 240, at least 250, at least 260, at least 270, at least 280, at least 290, at least 300, at least 310, at least 320, at least 330, at least 340, at least 350, at least 360, at least 370, at least 380, at least 390, or at least 400 °C.
  • the interior space of the liquification vessel may be maintained at a temperature of not more than 500, not more than 475, not more than 450, not more than 425, not more than 400, not more than 390, not more than 380, not more than 370, not more than 365, not more than 360, not more than 355, not more than 350, or not more than
  • the interior space of the liquification vessel may be maintained at a temperature ranging from 200 to 500 °C, 240 to 425 °C, 280 to 380 °C, or 320 to 350 °C.
  • the liquification zone may optionally contain equipment for removing halogens from the waste plastic stream 32.
  • halogen enriched gases can evolve.
  • the concentration of halogens in the liquified plastic stream can be reduced.
  • dehalogenation can be promoted by sparging a stripping gas (e.g., steam) into the liquified plastics in the melt tank.
  • the liquified plastic stream exiting the liquification zone can have a halogen content of less than 500, less than 400, less than 300, less than 200, less than 100, less than 50, less than 10, less than 5, less than 2, less than 1 , less than 0.5, or less than 0.1 ppmw.
  • the halogen content of the liquified plastic stream exiting the liquification zone can be not more than 95, not more than 90, not more than 75, not more than 50, not more than 25, not more than 10, or not more than 5 percent by weight of the halogen content of the waste plastic stream 32 introduced into the liquification zone.
  • the liquefied waste plastic stream 32 exiting the plastic liquification system may have a temperature of at least 200, at least 225, at least 250, at least 275, at least 300, at least 310, at least 320, at least 330, or at least 340 °C and/or less than 450, less than 425, less than 400, less than 375, or less than 350 °C.
  • At least a portion of the liquified plastic stream may be introduced into a downstream pyrolysis reactor 12 at a pyrolysis facility to produce a pyrolysis effluent 34, including pyrolysis oil and pyrolysis gas.
  • the chemical recycling facility 10 may comprise a pyrolysis facility, including a pyrolysis reactor 12.
  • pyrolysis refers to thermal decomposition of a feedstock of a biomass and/or a plastic material in solid or liquid form at elevated temperatures in an inert (i.e., substantially molecular oxygen free) atmosphere.
  • a “pyrolysis facility” is a facility that includes all equipment, lines, and controls necessary to carry out pyrolysis of waste plastic and feedstocks derived therefrom.
  • the pyrolysis facility can comprise the pyrolysis reactor 12 and, optionally, the plastic liquification zone and/or the separation zone.
  • the liquified plastic stream may be introduced into a downstream pyrolysis reactor 12 at a pyrolysis facility so as to produce a pyrolysis effluent stream 34 and an optional pyrolysis residue stream.
  • the liquified plastic stream to the pyrolysis facility may be a PO-enriched stream of waste plastic.
  • the liquified plastic stream introduced into the pyrolysis reactor 12 can be in the form of liquified plastic (e.g., liquified, melted, plasticized, depolymerized, or combinations thereof), plastic pellets or particulates, or a slurry thereof.
  • the pyrolysis facility may include the plastic liquification zone, the pyrolysis reactor 12, the condenser 24 for separating the pyrolysis effluent stream 34 from the reactor, and the separator 26 for the pyrolysis oil stream (discussed below).
  • pyrolysis effluent stream 34 exiting the pyrolysis reactor 12 can be in the form of pyrolysis vapors that comprise the pyrolysis gas and uncondensed pyrolysis oil.
  • pyrolysis vapor refers to the uncondensed pyrolysis effluent that comprises the majority of the pyrolysis oil and the pyrolysis gas present in the pyrolysis effluent.
  • Pyrolysis is a process that involves the chemical and thermal decomposition of the introduced feed. Although all pyrolysis processes may be generally characterized by a reaction environment that is substantially free of oxygen, pyrolysis processes may be further defined, for example, by the pyrolysis reaction temperature within the reactor, the residence time in the pyrolysis reactor 12, the reactor type, the pressure within the pyrolysis reactor 12, and the presence or absence of pyrolysis catalysts.
  • the pyrolysis reactor 12 can be, for example, a film reactor, a screw extruder, a tubular reactor, a tank, a stirred tank reactor, a riser reactor, a fixed bed reactor, a fluidized bed reactor, a rotary kiln, a vacuum reactor, a microwave reactor, or an autoclave.
  • the pyrolysis reactor 12 may comprise a film reactor, such as a falling film reactor or an up-flow film reactor.
  • a lift gas and/or a feed gas may be used to introduce the feedstock into the pyrolysis reactor 12 and/or facilitate various reactions within the pyrolysis reactor 12.
  • the lift gas and/or the feed gas may comprise, consist essentially of, or consist of nitrogen, carbon dioxide, and/or steam.
  • the lift gas and/or feed gas may be added with the waste plastic stream 32 prior to introduction into the pyrolysis reactor 12 and/or may be added directly to the pyrolysis reactor 12.
  • the lift gas and/or feed gas can include steam and/or a reducing gas such as hydrogen, carbon monoxide, and combinations thereof.
  • the temperature in the pyrolysis reactor 12 can be adjusted so as to facilitate the production of certain end products.
  • the pyrolysis temperature in the pyrolysis reactor 12 can range from 325 to 1 ,100°C, 350 to 900°C, 350 to 700°C, 350 to 550°C, 350 to 475°C, 425 to 1 ,100°C, 425 to 800°C, 500 to 1 ,100°C, 500 to 800°C, 600 to 1 ,100°C, 600 to 800°C, 625 to 1 ,000°C, 700 to 1 ,000°C, or 625 to 800°C.
  • the pyrolysis temperature in the pyrolysis reactor 12 can be greater than 625°C.
  • the pyrolysis temperature in the pyrolysis reactor 12 can be less than 625°C.
  • the residence times of the feedstocks within the pyrolysis reactor 12 can be at least 0.1 , at least 0.2, at least 0.3, at least 0.5, at least 1 , at least 1 .2, at least 1 .3, at least 2, at least 3, or at least 4 seconds.
  • the residence times of the feedstocks within the pyrolysis reactor 12 can be at least 1 , at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 20, at least 30, at least 45, at least 60, at least 75, or at least 90 minutes.
  • the residence times of the feedstocks within the pyrolysis reactor 12 can be less than 6, less than 5, less than 4, less than 3, less than 2, less than 1 , or less than 0.5 hours. Furthermore, the residence times of the feedstocks within the pyrolysis reactor 12 can be less than 100, less than 90, less than 80, less than 70, less than 60, less than 50, less than 40, less than 30, less than 20, less than 10, less than 9, less than 8, less than 7, less than 6, less than 5, less than 4, less than 3, less than 2, or less than 1 seconds.
  • the residence times of the feedstocks within the pyrolysis reactor 12 can range from 0.1 to 10 seconds, 0.5 to 10 seconds, 30 minutes to 4 hours, or 30 minutes to 3 hours, or 1 hour to 3 hours, or 1 hour to 2 hours.
  • the pressure within the pyrolysis reactor 12 can be maintained at atmospheric pressure or within the range of 0.1 to 100 bar, or 0.1 to 60 bar, or 0.1 to 30 bar, or 0.1 to 10 bar, 0.2 to 1 .5 bar, or 0.3 to 1 .1 bar.
  • bar refers to gauge pressure, unless otherwise noted.
  • a pyrolysis catalyst may be introduced into the liquified plastic stream prior to introduction into the pyrolysis reactor 12 and/or introduced directly into the pyrolysis reactor 12.
  • the catalyst can be homogenous or heterogeneous and may include, for example, certain types of zeolites and other mesostructured catalysts.
  • the pyrolysis reaction may not be catalyzed (e.g., carried out in the absence of a pyrolysis catalyst), but may include a non-catalytic, heat-retaining inert additive, such as sand, in the reactor in order to facilitate the heat transfer.
  • thermo pyrolysis Such catalyst-free pyrolysis processes may be referred to as “thermal pyrolysis.”
  • the pyrolysis effluent may be separated into the pyrolysis oil stream and the pyrolysis gas stream in a separation system, such as the condenser 24 depicted in FIG. 1.
  • this condenser 24 can include various types of equipment including, but not limited to a filter system, a multistage separator, a condensation zone, and/or a quench tower.
  • the pyrolysis effluent such as the pyrolysis vapors
  • the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, or at least 75 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • the pyrolysis effluent or pyrolysis vapors may comprise not more than 99, not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, or not more than 25 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • the pyrolysis oil may be in the form of uncondensed vapors in the pyrolysis effluent upon exiting the heated reactor; however, these vapors may be subsequently condensed into the resulting pyrolysis oil.
  • the pyrolysis effluent or pyrolysis vapors may comprise in the range of 20 to 99 weight percent, 25 to 80 weight percent, 30 to 85 weight percent, 30 to 80 weight percent, 30 to 75 weight percent, 30 to 70 weight percent, or 30 to 65 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, or at least 80 weight percent of the pyrolysis gas, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • the pyrolysis effluent or pyrolysis vapors may comprise not more than 99, not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, or not more than 45 weight percent of the pyrolysis gas, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • the pyrolysis effluent may comprise 1 to 90 weight percent, 10 to 85 weight percent, 15 to 85 weight percent, 20 to 80 weight percent, 25 to 80 weight percent, 30 to 75 weight percent, or 35 to 75 weight percent of the pyrolysis gas, based on the total weight of the stream.
  • the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 may comprise at least 0.5, at least 1 , at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • the pyrolysis effluent may comprise not more than 60, not more than 50, not more than 40, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 9, not more than 8, not more than 7, not more than 6, or not more than 5 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • the pyrolysis effluent may comprise in the range of 0.1 to 25 weight percent, 1 to 15 weight percent, 1 to 8 weight percent, or 1 to 5 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
  • This pyrolysis residue may be removed from the pyrolysis reactor 12 (where it may form) and/or separated from the pyrolysis effluent in a downstream separator, such as the condenser 24.
  • the resulting pyrolysis oil stream and pyrolysis gas stream may be directly used in various downstream applications based on their formulations.
  • the various characteristics and properties of the pyrolysis oil, pyrolysis gas, and pyrolysis residue are described below. It should be noted that, while all of the following characteristics and properties may be listed separately, it is envisioned that each of the following characteristics and/or properties of the pyrolysis gas, pyrolysis oil, and/or pyrolysis residue are not mutually exclusive and may be combined and present in any combination.
  • the pyrolysis oil may predominantly comprise hydrocarbons having from 4 to 30 carbon atoms per molecule (e.g., C4 to C30 hydrocarbons).
  • Cx or “Cx hydrocarbon,” refers to a hydrocarbon compound including “x” total carbons per molecule, and encompasses all olefins, paraffins, aromatics, heterocyclic, and isomers having that number of carbon atoms.
  • the pyrolysis oil may have a C4-C30 hydrocarbon content of at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent based on the total weight of the pyrolysis oil stream.
  • the pyrolysis oil can predominantly comprise C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons.
  • the pyrolysis oil may comprise at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent of C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons, based on the total weight of the pyrolysis oil stream.
  • the pyrolysis oil may also include various amounts of diolefins and aromatics, depending on the pyrolysis reactor 12 conditions and whether a pyrolysis catalyst is employed.
  • the pyrolysis oil may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent of diolefins and/or aromatics, based on the total weight of the pyrolysis oil stream.
  • the pyrolysis oil may include not more than 90, not more than 80, not more than 70, not more than 60, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, or not more than 1 weight percent of diolefins and/or aromatics, based on the total weight of the pyrolysis oil stream.
  • aromatics refers to the total amount (in weight) of any compounds containing an aromatic moiety, such as benzene, toluene, xylene, and styrene.
  • the pyrolysis oil may have a mid-boiling point in the range of 75 to 250 °C, 90 to 225 °C, or 115 to 190 °C as measured according to ASTM D-5399.
  • mid-boiling point refers to the median boiling point temperature of the pyrolysis oil, where 50 percent by volume of the pyrolysis oil boils above the mid-boiling point and 50 percent by volume boils below the mid-boiling point.
  • the boiling point range of the pyrolysis oil may be such that at least 90 percent of the pyrolysis oil boils off at a temperature of 250°C, of 280°C, of 290°C, of 300°C, or of 310°C, as measured according to ASTM D- 5399.
  • the pyrolysis conditions such as temperature, may be controlled so as to maximize the production of certain hydrocarbons and chemical compounds in the resulting pyrolysis gas and pyrolysis oil.
  • the pyrolysis reaction can occur at temperatures of least 625°C.
  • the pyrolysis effluent, the pyrolysis vapors, and/or the pyrolysis oil derived from such pyrolysis reactions may comprise the following compounds (all of the following weight percentages are based on the total weight of the associated stream):
  • the pyrolysis reaction can occur at temperatures of less than 625°C.
  • the pyrolysis effluent, the pyrolysis vapors, and/or the pyrolysis oil derived from such pyrolysis reactions may comprise the following compounds (all of the following weight percentages are based on the total weight of the associated stream):
  • the pyrolysis gas can have a methane content in the range of 1 to 50 weight percent, 5 to 50 weight percent, or 15 to 45 weight percent, based on the total weight of the pyrolysis gas stream.
  • the pyrolysis gas can have a C3 and/or C4 hydrocarbon content (including all hydrocarbons having 3 or 4 carbon atoms per molecule) in the range of 10 to 90 weight percent, 25 to 90 weight percent, or 25 to 80 weight percent, based on the total weight of the pyrolysis gas stream.
  • the pyrolysis gas can have a combined ethylene and propylene content of at least 25, at least 40, at least 50, at least 60, at least 70, or at least 75 weight percent, based on the total weight of the pyrolysis gas stream.
  • the pyrolysis residue comprises at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, or at least 85 weight percent of C20+ hydrocarbons based on the total weight of the pyrolysis residue.
  • C20+ hydrocarbon refers to hydrocarbon compounds containing at least 20 total carbons per molecule, and encompasses all olefins, paraffins, and isomers having that number of carbon atoms.
  • At least a portion of the pyrolysis gas stream and/or pyrolysis residue stream may be routed to one or more other chemical processing facilities, including, for example, the cracking facility. As shown in FIG. 1 , in some embodiments, at least a portion of the pyrolysis gas stream may be routed from the condenser 24 to the compressor system 18 of the cracking facility. The pyrolysis gas stream may be introduced into any stage of the downstream compressor 18.
  • the pyrolysis oil stream may be routed to a separation system (as shown as a separator 26 in FIG. 1) to thereby form an extract stream 28 and a raffinate stream 30.
  • the pyrolysis oil stream may be separated into the extract stream 28 and the raffinate stream 30 in the separation system via: (i) a solvent extraction process, which can separate these two streams based on their relative solubilities; (ii) membrane separation; (iii) adsorption, or (iv) extractive distillation.
  • the pyrolysis oil stream subjected to separation in the separation system may not undergo any hydroprocessing and/or hydrotreating prior to this separation step. Rather, in such embodiments, the pyrolysis oil stream may be immediately introduced into the separation system upon leaving the aforementioned condenser 24.
  • the solvent extraction process exploits the different solubilities of the various components (e.g., aromatics and diolefins) of the pyrolysis oil stream in a solvent.
  • the solvent extraction process generally involves placing the pyrolysis oil stream in contact with at least one extraction solvent that is either immiscible or only partially miscible with the pyrolysis oil stream.
  • the solvent may be chosen so that it can preferentially dissolve or extract the desired components (e.g., aromatics and/or diolefins) from the pyrolysis oil stream.
  • the two liquid phases that are then formed can be physically separated and the extract stream 28 (enriched in aromatics and/or diolefins) may be recovered and separated from the raffinate phase, usually by distillation.
  • Solvent extraction may also be used to further separate out specific types of lighter aromatics (e.g., benzene) from heavier aromatics (e.g., toluene).
  • Exemplary commercial solvent extraction systems that may be used as the separator 26 may include Sulfolane® by UQP, UdexTM by UOP, TetraTM by UOP, CaromTM by UOP, Arosolvan® by Lurgi, Morphylex® by Krupp Kopper and IFP, and Formex® by Enichem.
  • FIG. 2 An exemplary solvent extraction process and system 26 is depicted in FIG. 2.
  • the pyrolysis oil stream can be introduced into the extraction vessel 36, along with one or more extraction solvents, where the pyrolysis oil stream may flow in a countercurrent manner relative to the extraction solvents disclosed herein.
  • the aromatics and/or diolefins may be selectively dissolved in the extraction solvent. Consequently, as shown in FIG.
  • a raffinate stream 38 which is depleted in aromatics and/or diolefins (relative to the pyrolysis oil stream), may be removed from the overhead or near the top of the extraction vessel 36, washed in a water wash vessel 40, and then removed from the system. Meanwhile, the extract stream 42 from the bottom of the extraction vessel 36, which is enriched with aromatics and/or diolefins (relative to the pyrolysis oil stream), may be removed from the bottom of the extraction vessel 36 and further treated in a downstream distillation column 44.
  • the resulting overhead stream from the distillation column 44 may be sent as a reflux stream 46 back to the extraction vessel 36, while the bottom stream 48 may be further treated in a solvent recovery vessel 50 so as to form an overhead stream comprising the extract stream and a bottom stream 54 with the recovered solvent, which may be recycled back to the extraction vessel 36.
  • the overhead stream 52 may then be treated in a downstream separator 56 so as to form the extract stream, which may be removed for further processing and/or introduced back into the solvent recovery vessel 50.
  • the solvent extraction process may occur at temperatures in the range of 15 to 250 °C, 30 to 200 °C, or 40 to 175 °C.
  • extractive distillation processes may be used to separate the pyrolysis oil stream into the raffinate stream 30 and extract stream 28.
  • extractive distillation refers to processes in which a high-boiling solvent is added to a feed mixture (e.g., the pyrolysis oil stream) to alter the relative volatilities of the components to be separated.
  • the solvent increases the difference between the volatilities because of the nonideal behavior of the mixture.
  • the solvent may be withdrawn in the bottom (extract) product with the aromatics and/or diolefins, and solvent recovery can be accomplished via distillation. Extractive distillation has been favored for feedstocks that generally have a high aromatics content.
  • Exemplary commercial extractive distillation systems that may be used as the separator 26 include, for example, those by Glitsch, Krupp Koppers, and/or Lurgi.
  • An exemplary extractive distillation process and system is depicted in FIG. 3.
  • the extractive distillation process can involve feeding the pyrolysis oil stream and at least one extraction solvent to an extractive distillation column 58.
  • the resulting raffinate stream 30 may be removed from the overhead of the extractive distillation column.
  • the bottom stream 60 from the column may then be introduced into a solvent recovery vessel 50, which can further separate and recover the extraction solvent from this bottoms stream.
  • the recovered solvent 54 may be recycled back to the extractive distillation column.
  • the overhead stream 52 may then be treated in a downstream separator so as to form the extract stream, which may be removed for further processing and/or introduced back into the solvent recovery vessel 50.
  • the extractive distillation process may occur at temperatures in the range of 15 to 350 °C, 30 to 325 °C, or 40 to 300 °C.
  • the pyrolysis oil stream may be separated into the extract stream 28 and the raffinate stream 30 via a solvent extraction process or an extractive distillation process.
  • the extraction solvents used may include, for example, sulfolane, water, N- formylmorpholine, tetrahydrofurfuryl alcohol (THFA), sulfolane, furfural, tetraethylene glycol, dimethylsulfoxide, N-methyl-2-pyrrolidone, or combinations thereof.
  • the separator 26 shown in FIG. 1 can include various types of equipment including, but not limited to, a filter system, a multistage separator, a distillation column, an extractive distillation column, a tank, a separatory funnel, a countercurrent distribution system, a membrane system, a Craig apparatus, a spray column, a centrifugal contractor, a thin layer extraction vessel, a pulsed column, a rotating disk contractor, a sieve tray extractor, a Kuhni column, and/or a multistage mixer-settler.
  • the separator 26 in FIG. 1 can be a conventional Benzene-Toluene-Xylene (BTX) Unit, which is commonly used in the petrochemical industry.
  • BTX Benzene-Toluene-Xylene
  • the separator 26 in FIG. 1 can comprise a solvent extraction system comprising: (i) at least one extraction device (e.g., a rotating disk contractor, a sieve tray extractor, a vertical multistage mixer-settler, and/or a Kuhni column) and (ii) at least one distillation column in fluid communication with the extraction device.
  • the separator system 26 depicted in FIG. 1 can be used to recover most of the aromatics and/or diolefins present in the pyrolysis oil stream.
  • liquid products derived from the separator 20 in the cracking facility may also be introduced into the separation system 26 with the pyrolysis oil stream.
  • These liquid products from the cracking facility may contain large amounts of aromatics, such as benzene, toluene, xylene, and styrenes, and diolefins, such as cyclopentadiene and dicyclopentadiene.
  • this separator 26 in the pyrolysis facility may separate a combined stream containing the pyrolysis oil stream and the liquid products stream from the cracking facility into the extract stream and the raffinate stream.
  • the feed stream into the separator 26 may comprise at least 10, at least 25, at least 50, at least 75, at least 90, at least 95, or at least 99 weight percent of the pyrolysis oil stream, based on the total weight of the feed stream. Additionally, or in the alternative, the feed stream into the separator 26 may comprise not more than 99, not more than 90, not more than 80, not more than 70, not more than 60, not more than 50, not more than 40, not more than 30 weight percent of the pyrolysis oil stream, based on the total weight of the feed stream.
  • the feed stream into the separator 26 may comprise at least 10, at least 25, at least 50, at least 75, at least 90, at least 95, or at least 99 weight percent of the liquid product stream from the cracking facility, based on the total weight of the feed stream. Additionally, or in the alternative, the feed stream into the separator 26 may comprise not more than 99, not more than 90, not more than 80, not more than 70, not more than 60, not more than 50, not more than 40, not more than 30 weight percent of the liquid product stream from the cracking facility, based on the total weight of the feed stream.
  • the extract stream 28 may be enriched in aromatics (e.g., benzene, toluene, ethyl benzene, styrene, and/or xylene) and diolefins (e.g., cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof), which have been derived from the pyrolysis oil stream.
  • aromatics e.g., benzene, toluene, ethyl benzene, styrene, and/or xylene
  • diolefins e.g., cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof
  • the extract stream 28 may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, or not more than 65 weight percent of one or more aromatics, based on the total weight of the stream.
  • aromatics may include benzene, ethyl benzene, toluene, xylene, styrene, and/or derivatives thereof.
  • the extract stream 28 may comprise at least 0.01 , at least 0.05, at least 0.1 , at least 0.5, at least 1 , least 2, or least 3 weight percent and/or not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of one or more diolefins, based on the total weight of the stream.
  • Exemplary diolefins may include cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof.
  • the extract stream 28 may be subjected to further downstream separation, so as to recover specific diolefins and/or aromatics from the extract stream 28.
  • the diolefins, benzene, toluene, and/or xylene may be individually recovered from the extract stream 28 via a downstream solvent extraction process, an adsorption process, a membrane separation process, and/or an extract distillation process (described above).
  • at least a portion of the extract stream 28 itself and/or the individual chemical components therein may be removed from the chemical recycling facility 10 and sold to downstream chemical processors.
  • At least a portion of the extract stream 28 itself and/or the individual chemical components therein may be subjected to further downstream processing to thereby form other chemical derivatives and/or polymers.
  • at least a portion of the diolefins recovered from the extract stream 28 may be used to form hydrocarbons or other chemical derivatives.
  • the extract stream 28 may be separated into an aromatics stream and a diolefin stream. Any conventional separation technique may be used to separate the extract stream, such as extractive distillation, solvent extraction, or distillation.
  • the aromatics stream may be enriched in aromatics and depleted in diolefins (relative to the extract stream) and the diolefin stream may be enriched in diolefins and depleted in aromatics (relative to the extract stream).
  • At least a portion of the aromatics stream and/or the diolefin stream may be sold to downstream chemical processors for downstream processing.
  • at least a portion of the aromatics stream and/or the diolefin stream may be subjected to downstream processing to form chemical derivatives, polymers, fuels, and/or other hydrocarbons.
  • the raffinate stream 30 may be depleted in aromatics (e.g., benzene, toluene, ethyl benzene, styrene, and/or xylene) and diolefins (e.g., cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof), relative to the pyrolysis oil stream.
  • aromatics e.g., benzene, toluene, ethyl benzene, styrene, and/or xylene
  • diolefins e.g., cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof
  • the raffinate stream 30 comprises not more than 50, not more than 40, not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of benzene, ethyl benzene, toluene, xylenes, styrene, and/or total diolefins, based on the total weight of the raffinate stream.
  • the raffinate stream 30 comprises at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, or not more than 65 weight percent of cyclopentadiene and/or dicyclopentadiene, based on the total weight of the raffinate stream.
  • the raffinate stream 30 comprises not more than 50, not more than 40, not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of aromatics, such as benzene, ethyl benzene, toluene, xylenes, and/or styrene, based on the total weight of the raffinate stream.
  • aromatics such as benzene, ethyl benzene, toluene, xylenes, and/or styrene
  • the raffinate stream 30 comprises not more than 50, not more than 40, not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of diolefins, such as cyclopentadiene, dicycloplentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof, based on the total weight of the raffinate stream.
  • diolefins such as cyclopentadiene, dicycloplentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof, based on the total weight of the raffinate stream.
  • At least a portion of the raffinate stream 30 may be subjected to further downstream treatment and processing in the cracking facility.
  • At least a portion of one or more streams from the pyrolysis facility, including the raffinate stream 30 and/or the pyrolysis gas stream, may be introduced into a cracking facility.
  • the term “cracking” refers to breaking down complex organic molecules into simpler molecules by the breaking of carbon-carbon bonds.
  • a “cracking facility” is a facility that includes all equipment, lines, and controls necessary to carry out cracking of a feedstock derived from waste plastic.
  • a cracking facility can include one or more cracker furnaces 14, a quench system 16 for cooling the cracked products, a compression system, and a downstream separation zone including equipment used to process the effluent of the cracker furnace(s) 14.
  • the cracker facility may include a cracker furnace 14, a quench system 16, a compression system, and a separation zone downstream of the cracker furnace 14 for separating the furnace effluent into various end products, such as a recycle content olefin (r-olefin) stream.
  • r-olefin recycle content olefin
  • at least a portion of the raffinate stream 30 and/or the pyrolysis gas stream can be sent to the cracking facility.
  • the raffinate stream 30 may be introduced into an inlet of the cracker furnace 14, while the pyrolysis gas stream can be introduced into a location upstream or downstream of the furnace.
  • the effluent from the cracker furnace 14 may be separated into gas products and liquid products in the downstream separator, as shown in FIG. 1.
  • the raffinate stream 30 and/or pyrolysis gas stream may optionally be combined with a stream of cracker feed to form the feed stream to the cracking facility.
  • the cracker feed stream can include a hydrocarbon feed other than the pyrolysis gas and the raffinate stream in an amount of from 5 to 95 weight percent, 10 to 90 weight percent, or 15 to 85 weight percent, based on the total weight of the cracker feed.
  • the cracker facility may comprise a single cracking furnace, or it can have at least 2, or at least 3, or at least 4, or at least 5, or at least 6, or at least 7, or at least 8 or more cracking furnaces operated in parallel. Any one or each furnace(s) may be gas cracker, or a liquid cracker, or a split furnace.
  • the cracker feed stream, along with the raffinate stream and/or pyrolysis gas, may pass through the cracking furnace, wherein the hydrocarbon components therein are thermally cracked to form lighter hydrocarbons, including olefins such as ethylene, propylene, and/or butadiene.
  • the residence time of the cracker stream in the furnace can be in the range of from 0.15 to 2 seconds, 0.20 to 1.75 seconds, or 0.25 to 1.5 seconds.
  • the temperature of the cracked olefin-containing effluent withdrawn from the furnace outlet can be in the range of from 730 to 900 °C, 750 to 875 °C, or 750 to 850 °C.
  • the olefin-containing gas products stream withdrawn from the separator in the cracking facility (as shown in FIG.
  • the olefin-containing gas products stream may comprise predominantly ethylene, predominantly propylene, or predominantly ethylene and propylene, based on the total weight of the olefin-containing effluent stream.
  • a liquid products stream which is enriched in aromatics and diolefins, may be also recovered from the separator in the cracking facility as shown in FIG. 1 .
  • the liquid products stream derived from cracking facility may comprise at least 0.01 , at least 0.05, or at least 0.1 weight percent and/or not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of one or more diolefins, based on the total weight of the stream.
  • Exemplary diolefins may include cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof.
  • the liquid products stream derived from cracking facility may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, or not more than 65 weight percent of one or more aromatics, based on the total weight of the stream.
  • aromatics may include benzene, ethyl benzene, toluene, xylene, styrene, and/or derivatives thereof.
  • the pyrolysis gas stream when introduced into the cracker facility, may be introduced into the inlet of the cracker furnace 14, or all or a portion of the pyrolysis gas stream may be introduced downstream of the furnace outlet, at a location upstream of or within the separation zone of the cracker facility.
  • the pyrolysis gas when introduced into or upstream of the separation zone, can be introduced upstream of the last stage of compression in the compressor, or prior to the inlet of at least one fractionation column in a fractionation section of the separator.
  • the olefin-containing effluent stream may be cooled rapidly (e.g., quenched) in the quench system 16 in order to prevent production of large amounts of undesirable by-products and to minimize fouling in downstream equipment.
  • At least a portion of one or more of the above streams may be introduced into one or more of the facilities shown in FIG. 1 , while, in other embodiments, all or a portion of the streams withdrawn from the separation zone of the cracking facility may be routed to further separation and/or storage, transportation, sale, and/or use.
  • At least a portion of the liquid products stream from the cracking facility may be routed to the separator in the pyrolysis facility, so as to recover the aromatics and diolefins from this stream.
  • the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.
  • the phrase “at least a portion” includes at least a portion and up to and including the entire amount or time period.
  • the term “chemical recycling” refers to a waste plastic recycling process that includes a step of chemically converting waste plastic polymers into lower molecular weight polymers, oligomers, monomers, and/or non-polymeric molecules (e.g., hydrogen, carbon monoxide, methane, ethane, propane, ethylene, and propylene) that are useful by themselves and/or are useful as feedstocks to another chemical production process(es).
  • the term “chemical recycling facility” refers to a facility for producing a recycle content product via chemical recycling of waste plastic.
  • co-located refers to the characteristic of at least two objects being situated on a common physical site, and/or within one mile of each other.
  • the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.
  • the term “depleted” refers to having a concentration (on a dry weight basis) of a specific component that is less than the concentration of that component in a reference material or stream.
  • directly derived refers to having at least one physical component originating from waste plastic.
  • enriched refers to having a concentration (on a dry weight basis) of a specific component that is greater than the concentration of that component in a reference material or stream.
  • halide refers to a composition comprising a halogen atom bearing a negative charge (i.e., a halide ion).
  • halogen refers to organic or inorganic compounds, ionic, or elemental species comprising at least one halogen atom.
  • the term “indirectly derived” refers to having an assigned recycle content i) that is attributable to waste plastic, but ii) that is not based on having a physical component originating from waste plastic.
  • the term “isolated” refers to the characteristic of an object or objects being by itself or themselves and separate from other materials, in motion or static.
  • mixed plastic waste and “MPW” refer to a mixture of at least two types of waste plastics including, but not limited to the following plastic types: polyethylene terephthalate (PET), one or more polyolefins (PO), and polyvinylchloride (PVC).
  • PET polyethylene terephthalate
  • PO polyolefins
  • PVC polyvinylchloride
  • overhead refers to the physical location of a structure that is above a maximum elevation of quantity of particulate plastic solids within an enclosed structure.
  • partially processed waste plastic means waste plastic that has been subjected to at least on automated or mechanized sorting, washing, or comminuted step or process.
  • Partially processed waste plastics may originate from, for example, municipal recycling facilities (MRFs) or reclaimers. When partially processed waste plastic is provided to the chemical recycling facility, one or more preprocessing steps may me skipped.
  • MRFs municipal recycling facilities
  • preprocessing steps may me skipped.
  • physical recycling also known as “mechanical recycling” refers to a waste plastic recycling process that includes a step of melting waste plastic and forming the molten plastic into a new intermediate product (e.g., pellets or sheets) and/or a new end product (e.g., bottles). Generally, physical recycling does not substantially change the chemical structure of the plastic, although some degradation is possible.
  • plastic may include any organic synthetic polymers that are solid at 25°C and 1 atmosphere of pressure.
  • the term “predominantly” means more than 50 percent by weight.
  • a predominantly propane stream, composition, feedstock, or product is a stream, composition, feedstock, or product that contains more than 50 weight percent propane.
  • preprocessing refers to preparing waste plastic for chemical recycling using one or more of the following steps: (i) comminuting, (ii) particulating, (iii) washing, (iv) drying, and/or (v) separating.
  • pyrolysis refers to thermal decomposition of a feedstock of a biomass and/or a plastic material in solid or liquid form at elevated temperatures in an inert (i.e., substantially molecular oxygen free) atmosphere.
  • pyrolysis char refers to a carbon- containing composition obtained from pyrolysis that is solid at 200°C and 1 atm.
  • pyrolysis gas and “pygas” refer to a composition obtained from pyrolysis that is gaseous at 25°C at 1 atm.
  • pyrolysis heavy waxes refers to C20+ hydrocarbons obtained from pyrolysis that are not pyrolysis char, pyrolysis gas, or pyrolysis oil.
  • pyrolysis oil or “pyoil” refers to a composition obtained from pyrolysis that is liquid at 25°C and 1 atm.
  • pyrolysis residue refers to a composition obtained from pyrolysis that is not pyrolysis gas or pyrolysis oil and that comprises predominantly pyrolysis char and pyrolysis heavy waxes.
  • cycle content and “r-content” refer to being or comprising a composition that is directly and/or indirectly derived from waste plastic.
  • r-pyrolysis gas or “r-pygas” refer to being or comprising a pyrolysis gas that is directly and/or indirectly derived from waste plastic.
  • r-pyrolysis oil or “r-pyoil” refer to being or comprising a pyrolysis oil that is directly and/or indirectly derived from waste plastic.
  • waste plastic and “plastic waste” refer to used, scrap, and/or discarded plastic materials.
  • the waste plastic fed to the chemical recycling facility may be unprocessed or partially processed.
  • unprocessed waste plastic means waste plastic that has not be subjected to any automated or mechanized sorting, washing, or comminuting.
  • unprocessed waste plastic include waste plastic collected from household curbside plastic recycling bins or shared community plastic recycling containers.
  • downstream means a target unit operation, vessel, or equipment that: a. is in fluid (liquid or gas) communication, or in piping communication, with an outlet stream from the radiant section of a cracker furnace, optionally through one or more intermediate unit operations, vessels, or equipment, or b. was in fluid (liquid or gas) communication, or in piping communication, with an outlet stream from the radiant section of a cracker furnace, optionally through one or more intermediate unit operations, vessels, or equipment, provided that the target unit operation, vessel, or equipment remains within the battery limits of the cracker facility (which includes the furnace and all associated downstream separation equipment).
  • each number is modified the same as the first number or last number in the numerical sequence or in the sentence, e.g., each number is “at least,” or “up to” or “not more than” as the case may be; and each number is in an “or” relationship.
  • “at least 10, 20, 30, 40, 50, 75 wt.%...” means the same as “at least 10 wt.%, or at least 20 wt.%, or at least 30 wt.%, or at least 40 wt.%, or at least 50 wt.%, or at least 75 wt.%,” etc.; and “not more than 90 wt.%, 85, 70, 60...” means the same as “not more than 90 wt.%, or not more than 85 wt.%, or not more than 70 wt.%....” etc.; and “at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% by weight...” means the same as “ at least 1 wt.%, or at least 2 wt.%, or at least 3 wt.% ...” etc.; and “at least 5, 10, 15, 20 and/or not more than 99, 95, 90 weight percent” means the same as “at least 5 wt.%,

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Abstract

It has been discovered that high volumes of valuable recycle content products may be directly derived from waste plastic pyrolysis effluent. More particularly, one or more valuable recycle content hydrocarbons, such as aromatics and diolefins, can be separated from recycle content pyrolysis oil prior to further treatment in a downstream cracker facility. Consequently, by recovering these valuable recycle content products upstream of the cracking facility, one can optimize recovery and utilization of recycle content products from waste plastics.

Description

RECOVERY OF VALUABLE CHEMICAL PRODUCTS FROM RECYCLE CONTENT PYROLYSIS OIL
BACKGROUND
[0001] Waste plastic pyrolysis plays a part in a variety of chemical recycling technologies. The pyrolysis of waste plastic produces heavy components (e.g., waxes, tar, and char), as well as recycle content pyrolysis oil (r-pyoil) and recycle content pyrolysis gas (r-pygas). When the pyrolysis facility is located near another processing facility, such as a cracker facility, it is desirable to send as much of the r-pyoil and r-pygas as possible to the downstream processing facility to be used as a feedstock in forming other recycle content products (e.g., olefins, paraffins, etc.).
[0002] However, when pyrolysis facilities are added to existing downstream facilities, such as a cracking facility, the direct recovery of desirable recycle products from the pyrolysis effluent may not be considered. Consequently, even though recycle content products are being produced by the pyrolysis facilities, these recycle content products are typically broken down in downstream processes and not sufficiently recovered. Therefore, such combined facilities may exhibit one or more process deficiencies that negatively impact the ability to directly recover valuable recycle content products from the pyrolysis effluent. Thus, a processing scheme for waste plastic pyrolysis that provides superior recycle content product recovery is needed.
SUMMARY
[0003] In one aspect, the present technology concerns a chemical recycling process. Generally, the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis oil stream; (b) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; and (c) introducing at least a portion of the raffinate stream into a cracker furnace. [0004] In one aspect, the present technology concerns a chemical recycling process. Generally, the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent; (b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream; (c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; (d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed; (e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; (f) compressing at least a portion of the cracked product in at least one compressor to form a compressed product; and (g) separating at least one hydrocarbon from the compressed product to thereby form a recycle content hydrocarbon stream.
[0005] In one aspect, the present technology concerns a chemical recycling process. Generally, the process comprises: (a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent; (b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream; (c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins; (d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed; (e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; and (f) subjecting at least a portion of the extract stream to a chemical process so as to synthesize a chemical derivative and/or a polymer therefrom.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a block flow diagram illustrating the main steps of a process and facility for chemically recycling waste plastic and recovering desirable recycle content products from the pyrolysis effluent according to embodiments of the present technology;
[0007] FIG. 2 is an exemplary depiction of a solvent extraction process and facility for recovering aromatics and/or diolefins from the pyrolysis oil stream; and
[0008] FIG. 3 is an exemplary depiction of an extractive distillation process and facility for recovering aromatics and/or diolefins from the pyrolysis oil stream.
DETAILED DESCRIPTION
[0009] We have discovered that high volumes of valuable recycle content products may be directly derived from waste plastic pyrolysis effluent. More particularly, we have discovered that one or more valuable recycle content hydrocarbons can be separated from recycle content pyrolysis oil prior to further treatment in a downstream cracker facility. Consequently, by recovering these valuable recycle content products upstream of the cracking facility, we can optimize recovery and utilization of recycle content products from waste plastics.
[0010] FIG. 1 depicts an exemplary chemical recycling facility 10 comprising a pyrolysis reactor 12 and a cracking facility comprising a cracker furnace 14, a quench system 16, a compression system 18, and a separator 20.
[0011] As shown in FIG. 1 , the chemical recycling facility 10 may also contain a waste plastic source 22 and a condenser 24 for separating the pyrolysis effluent into a pyrolysis oil stream and a pyrolysis gas stream. As noted above, the chemical recycling facility 10 described herein is able to recover a number of valuable recycle content products from the pyrolysis effluent, prior to downstream treatment in a cracking facility. As depicted in FIG. 1 , at least a portion of the pyrolysis oil stream may be treated in a separator 26, such a solvent extraction vessel, to thereby form an extract stream 28 that is enriched in aromatics and/or diolefins and a raffinate stream 30 that is depleted in aromatics and/or diolefins, both relative to the pyrolysis oil stream. The extract stream 28 may be removed from the facility and be used in or sold to chemical facilities who can produce various products, polymers, and/or chemical derivatives from the aromatics and/or diolefins. It should be understood that FIG. 1 depicts one exemplary embodiment of the present technology. Certain features depicted in FIG. 1 may be omitted and/or additional features described elsewhere herein may be added to the system depicted in FIG. 1 . The various process steps are described below in greater detail.
Overall Chemical Recycling Facility
[0012] Turning now to FIG. 1 , the main steps of a process for chemically recycling waste plastic in a chemical recycling facility 10 are shown.
Chemical recycling processes and facilities as described herein may be used to convert waste plastic to recycle content products or chemical intermediates used to form a variety of end use materials. The waste plastic fed to the chemical recycling facility/process can be mixed plastic waste (MPW), presorted waste plastic, and/or pre-processed waste plastic. As shown in FIG. 1 , the waste plastic feed stream 32 may be derived from the waste plastic source 22, which may include a waste plastic preprocessing facility.
[0013] In an embodiment or in combination with any embodiment mentioned herein, the chemical recycling facility 10 may be a commercialscale facility capable of processing significant volumes of mixed plastic waste. As used herein, the term “commercial scale facility” refers to a facility having an average annual feed rate of at least 500 pounds per hour, averaged over one year.
[0014] In an embodiment or in combination with any embodiment mentioned herein, two or more of the facilities shown in FIG. 1 , such as the pyrolysis facility (e.g., the pyrolysis reactor 12, the waste plastic source 22, the condenser 24, and the separator 26) and the cracking facility (e.g., the cracker furnace 14, the quench system 16, the compressor system 18, and the separator 20) may be co-located with one another. As used herein, the term “co-located” refers to facilities in which at least a portion of the process streams and/or supporting equipment or services are shared between the two facilities. When two or more of the facilities shown in FIG. 1 are co-located, the facilities may meet at least one of the following criteria (i) through (v): (i) the facilities share at least one non-residential utility service; (ii) the facilities share at least one service group; (iii) the facilities are owned and/or operated by parties that share at least one property boundary; (iv) the facilities are connected by at least one conduit configured to carry at least one process material (e.g., solid, liquid and/or gas fed to, used by, or generated in a facility) from one facility to another; and (v) the facilities are within 40, within 35, within 30, within 20, within 15, within 12, within 10, within 8, within 5, within 2, or within 1 mile of one another, measured from their geographical center. At least one, at least two, at least three, at least four, or all of the above statements (i) through (v) may be true.
[0015] Regarding (i), examples of suitable utility services include, but are not limited to, steam systems (co-generation and distribution systems), cooling water systems, heat transfer fluid systems, plant or instrument air systems, nitrogen systems, hydrogen systems, non-residential electrical generation and distribution, including distribution above 8000V, non- residential wastewater/sewer systems, storage facilities, transport lines, flare systems, and combinations thereof.
[0016] Regarding (ii), examples of service groups and facilities include, but are not limited to, emergency services personnel (fire and/or medical), a third- party vendor, a state or local government oversight group, and combinations thereof. Government oversight groups can include, for example, regulatory or environmental agencies, as well as municipal and taxation agencies at the city, county, and state level.
[0017] Regarding (iii), the boundary may be, for example, a fence line, a property line, a gate, or common boundaries with at least one boundary of a third-party owned land or facility.
[0018] Regarding (iv), the conduit may be a fluid conduit that carries a gas, a liquid, a solid/liquid mixture (e.g., slurry), a solid/gas mixture (e.g., pneumatic conveyance), a solid/liquid/gas mixture, or a solid (e.g., belt conveyance). In some cases, two units may share one or more conduits selected from the above list.
[0019] Turning again to FIG. 1 , a stream of waste plastic, which can be mixed plastic waste (MPW), may be introduced into the chemical recycling facility 10 from the waste plastic source 22. As used herein, the terms “waste plastic” and “plastic waste” refer to used, scrap, and/or discarded plastic materials, such as plastic materials typically sent to a landfill. The waste plastic stream 32 fed to the chemical recycling facility 10 may include unprocessed or partially processed waste plastic. As used herein, the term “unprocessed waste plastic” means waste plastic that has not be subjected to any automated or mechanized sorting, washing, or comminuting. Examples of unprocessed waste plastic include waste plastic collected from household curbside plastic recycling bins or shared community plastic recycling containers. Partially processed waste plastics may originate from, for example, municipal recycling facilities (MRFs) or reclaimers. In certain embodiments, the waste plastic may comprise at least one of post-industrial (or pre-consumer) plastic and/or post-consumer plastic.
[0020] In an embodiment or in combination with any embodiment mentioned herein, the mixed waste plastic (MPW) includes at least two distinct types of plastic.
[0021] In an embodiment or in combination with any embodiment mentioned herein, all or a portion of the MPW in the waste plastic stream 32 can originate from a municipal recycling facility (MRF).
[0022] In an embodiment or in combination with any embodiment mentioned herein, all or a portion of the MPW in the waste plastic stream 32 can originate from a reclaimer facility.
[0023] Examples of suitable waste plastics can include, but are not limited to, polyolefins (PO), aromatic and aliphatic polyesters, polyvinyl chloride (PVC), polystyrene, cellulose esters, polytetrafluoroethylene, acrylobutadienestyrene (ABS), cellulosics, epoxides, polyamides, phenolic resins, polyacetal, polycarbonates, polyphenylene-based alloys, poly(methyl methacrylate), styrene-containing polymers, polyurethane, vinyl-based polymers, styrene acrylonitrile, and urea-containing polymers and melamines. [0024] Examples of specific polyolefins may include linear low-density polyethylene (LLDPE), low density polyethylene (LDPE), polymethylpentene, polybutene-1 , high density polyethylene (HDPE), atactic polypropylene, isotactic polypropylene, syndiotactic polypropylene, crosslinked polyethylene, amorphous polyolefins, and the copolymers of any one of the aforementioned polyolefins.
[0025] Examples of polyesters can include those having repeating aromatic or cyclic units such as those containing a repeating terephthalate, isophthalate, or naphthalate units such as PET, modified PET, and PEN, or those containing repeating furanate repeating units. As used herein, “PET” or “polyethylene terephthalate” refers to a homopolymer of polyethylene terephthalate, or to a polyethylene terephthalate modified with one or more acid and/or glycol modifiers and/or containing residues or moieties of other than ethylene glycol and terephthalic acid, such as isophthalic acid, 1 ,4- cyclohexanedicarboxylic acid, diethylene glycol, 2,2,4,4-tetramethyl-1 ,3- cyclobutanediol (TMCD), cyclohexanedimethanol (CHDM), propylene glycol, isosorbide, 1 ,4-butanediol, 1 ,3-propane diol, and/or neopentyl glycol (NPG). [0026] In an embodiment or in combination with any embodiment mentioned herein, the waste plastic stream 32 comprises at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent of one or more polyolefins, based on the total weight of the stream. Alternatively, or in addition, the waste plastic stream 32 comprises not more than 99.9, not more than 99, not more than 97, not more than 92, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, or not more than 5 weight percent of one or more polyolefins, based on the total weight of the stream. [0027] In one embodiment or in combination with any of the mentioned embodiments, the waste plastic stream 32 comprises not more than 20, not more than 15, not more than 12, not more than 10, not more than 8, not more than 6, not more than 5, not more than 4, not more than 3, not more than 2, or not more than 1 weight percent of polyesters, based on the total weight of the stream.
[0028] In one embodiment or in combination with any of the mentioned embodiments, the waste plastic stream 32 comprises not more than 20, not more than 15, not more than 12, not more than 10, not more than 8, not more than 6, not more than 5, not more than 4, not more than 3, not more than 2, or not more than 1 weight percent of biowaste materials, based on the total weight of the stream. As used herein, the term “biowaste” refers to material derived from living organisms or of organic origin. Exemplary biowaste materials include, but are not limited to, cotton, wood, saw dust, food scraps, animals and animal parts, plants and plant parts, and manure.
[0029] In an embodiment or in combination with any embodiment mentioned herein, the waste plastic stream 32 can include not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.75, or not more than 0.5 weight percent of polyvinyl chloride (PVC), based on the total weight of the stream.
[0030] The general configuration and operation of each of the facilities that may be present in the chemical recycling facility 10 shown in FIG. 1 will now be described in further detail below, beginning with the optional preprocessing facility of the waste plastic source 22.
Optional Plastic Preprocessing
[0031] As shown in FIG. 1 , unprocessed, partially processed, and/or processed waste plastic, such as mixed plastic waste (MPW), may first be introduced into the chemical recycling facility 10 via the waste plastic stream 32 from the waste plastic source 22. As noted above, the waste plastic source 22 may include an optional preprocessing facility that can prepare the waste plastic feedstock for the downstream recycling processes. While in the optional preprocessing facility, the waste plastic feedstock may undergo one or more preprocessing steps to prepare it for chemical recycling. As used herein, the term “preprocessing facility” refers to a facility that includes all equipment, lines, and controls necessary to carry out the preprocessing of waste plastic. Preprocessing facilities as described herein may employ any suitable method for carrying out the preparation of waste plastic for chemical recycling using one or more of following steps, which are described in further detail below. Alternatively, in certain embodiments, the waste plastic source 22 does not contain a preprocessing facility and the waste plastic stream 32 is not subjected to any preprocessing before any of the downstream chemical recycling steps described herein.
[0032] In an embodiment or in combination with any embodiment mentioned herein, the preprocessing facility of the waste plastic source 22 may include at least one separation step or zone. The separation step or zone may be configured to separate the waste plastic stream 32 into two or more streams enriched in certain types of plastics. Such separation is particularly advantageous when the waste plastic fed to the chemical recycling facility 10 is MWP.
[0033] Any suitable type of separation device, system, or facility may be employed to separate the waste plastic into two or more streams enriched in certain types of plastics such as, for example, a PET-enriched stream and a PO-enriched stream. Examples of suitable types of separation include mechanical separation and density separation, which may include sink-float separation and/or centrifugal density separation. As used herein, the term “sink-float separation” refers to a density separation process where the separation of materials is primarily caused by floating or sinking in a selected liquid medium, while the term “centrifugal density separation” refers to a density separation process where the separation of materials is primarily caused by centrifugal forces.
[0034] Referring again to FIG. 1 , the waste plastic stream 32 may be introduced into one or more downstream processing facilities (or undergo one or more downstream processing steps) within the chemical recycling facility 10. In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the waste plastic stream 32 may be directly or indirectly introduced into a plastic liquification zone within the waste plastic source 22 or outside of it. Additional details of each step, as well as the general integration of each of these steps or facilities with one or more of the others according to one or more embodiments of the present technology are discussed in further detail below.
Liquification/Dehalogenation
[0035] The waste plastic stream 32 may be introduced into a plastic liquification zone prior to being introduced into the pyrolysis reactor 12. The plastic liquification zone may be present in the waste plastic source 22 or it may be positioned separately and independently. As used herein, the term “liquification” zone refers to a chemical processing zone or step in which at least a portion of the incoming plastic is liquefied. The step of liquefying plastic can include chemical liquification, physical liquification, or combinations thereof. Exemplary methods of liquefying the plastic introduced in the liquification zone can include: (i) heating/melting; (ii) dissolving in a solvent; (iii) depolymerizing; (iv) plasticizing; and combinations thereof. Additionally, one or more of options (i) through (iv) may also be accompanied by the addition of a blending or liquification agent to help facilitate the liquification (reduction of viscosity) of the polymer material. As such, a variety of rheology modification agents (e.g., solvents, depolymerization agents, plasticizers, and blending agents) can be used the enhance the flow and/or dispersibility of the liquified waste plastic.
[0036] When added to the liquification zone, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent of the plastic (usually waste plastic) originally present in the waste plastic stream 32 undergoes a reduction in viscosity. In some cases, the reduction in viscosity can be facilitated by heating (e.g., addition of steam directly or indirectly contacting the plastic), while, in other cases, it can be facilitated by combining the plastic with a solvent capable of dissolving it. Examples of suitable solvents can include, but are not limited to, alcohols such as methanol or ethanol, glycols such as ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, cyclohexanedimethanol, glycerin, pyrolysis oil, motor oil, and water. This dissolution solvent can be added directly to the liquification vessel in the liquification zone, or it can be previously combined with one or more streams fed to the liquification zone, including the waste plastic stream 32.
[0037] In an embodiment or in combination with any embodiment mentioned herein, the dissolution solvent can comprise a stream withdrawn from one or more other facilities within the chemical recycling facility 10. For example, the solvent can comprise a stream withdrawn from the pyrolysis reactor 12 and/or the separation zone. In certain embodiments, the dissolution solvent can be or comprise pyrolysis oil.
[0038] In some cases, the waste plastic can be depolymerized such that, for example, the number average chain length of the plastic is reduced by contact with a depolymerization agent. In an embodiment or in combination with any embodiment mentioned herein, at least one of the previously-listed solvents may be used as a depolymerization agent, while, in one or more other embodiments, the depolymerization agent can include an organic acid (e.g., acetic acid, citric acid, butyric acid, formic acid, lactic acid, oleic acid, oxalic, stearic acid, tartaric acid, and/or uric acid) or inorganic acid such as sulfuric acid (for polyolefins). The depolymerization agent may reduce the melting point and/or viscosity of the polymer by reducing its number average chain length.
[0039] Alternatively, or additionally, a plasticizer can be used in the liquification zone to reduce the viscosity of the plastic. Plasticizers for polyethylene include, for example, dioctyl phthalate, dioctyl terephthalate, glyceryl tribenzoate, polyethylene glycol having molecular weight of up to 8,000 Daltons, sunflower oil, paraffin wax having molecular weight from 400 to 1 ,000 Daltons, paraffinic oil, mineral oil, glycerin, EPDM, and EVA.
Plasticizers for polypropylene include, for example, dioctyl sebacate, paraffinic oil, isooctyl tallate, plasticizing oil (Drakeol 34), naphthenic and aromatic processing oils, and glycerin. Plasticizers for polyesters include, for example, polyalkylene ethers (e.g., polyethylene glycol, polytetramethylene glycol, polypropylene glycol or their mixtures) having molecular weight in the range from 400 to 1500 Daltons, glyceryl monostearate, octyl epoxy soyate, epoxidized soybean oil, epoxy tallate, epoxidized linseed oil, polyhydroxyalkanoate, glycols (e.g., ethylene glycol, pentamethylene glycol, hexamethylene glycol, etc.), phthalates, terephthalates, trimellitate, and polyethylene glycol di-(2-ethylhexoate). When used, the plasticizer may be present in an amount of at least 0.1 , at least 0.5, at least 1 , at least 2, or at least 5 weight percent and/or not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent, based on the total weight of the waste plastic stream 32, or it can be in a range of from 0.1 to 10 weight percent, 0.5 to 8 weight percent, or 1 to 5 weight percent, based on the total weight of the waste plastic stream 32. [0040] Further, one or more of the methods of liquefying the waste plastic stream 32 can also include adding at least one blending agent to the plastic stream before, during, or after the liquification process in the liquification zone. Such blending agents may include for example, emulsifiers and/or surfactants, and may serve to more fully blend the liquified plastic into a single phase, particularly when differences in densities between the plastic components of a mixed plastic stream result in multiple liquid or semi-liquid phases. When used, the blending agent may be present in an amount of at least 0.1 , at least 0.5, at least 1 , at least 2, or at least 5 weight percent and/or not more than 10, not more than 8, not more than 5, not more than 3, not more than 2, or not more than 1 weight percent, based on the total weight of the waste plastic stream 32, or it can be in a range of from 0.1 to 10 weight percent, 0.5 to 8 weight percent, or 1 to 5 weight percent, based on the total weight of the waste plastic stream 32.
[0041] In an embodiment or in combination with any embodiment mentioned herein, a portion of the pyrolysis oil stream withdrawn from the condenser 24 can be combined with the waste plastic stream 32 to form a liquified plastic. Generally, in such embodiments, all or a portion of the pyrolysis oil stream may be combined with the waste plastic stream 32 prior to introduction into the liquification zone, or after the waste plastic stream 32 enters the liquification vessel within the liquification zone.
[0042] In an embodiment or in combination with any embodiment mentioned herein, the liquified (or reduced viscosity) plastic stream withdrawn from the liquification zone can include at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95, or at least 99 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, not more than 2, or not more than 1 weight percent of one or more polyolefins, based on the total weight of the stream, or the amount of polyolefins can be in the range of from 1 to 99 weight percent, 5 to 90 weight percent, or 10 to 85 weight percent, based on the total weight of the stream.
[0043] In an embodiment or in combination with any embodiment mentioned herein, the liquified plastic stream exiting the liquification zone can have a viscosity of less than 3,000, less than 2,500, less than 2,000, less than 1 ,500, less than 1 ,000, less than 800, less than 750, less than 700, less than 650, less than 600, less than 550, less than 500, less than 450, less than 400, less than 350, less than 300, less than 250, less than 150, less than 100, less than 75, less than 50, less than 25, less than 10, less than 5, or less than 1 poise, as measured using a Brookfield R/S rheometer with a V80-40 vane spindle operating at a shear rate of 10 rad/s and a temperature of 350°C.
[0044] In an embodiment or in combination with any embodiment mentioned herein, the liquification zone may comprise at least one melt tank and/or at least one extruder to facilitate the plastic liquification. Additionally, in certain embodiments, the liquification zone may also contain at least one stripping column and at least one disengagement vessel to facilitate the removal of halogenated compounds that may be formed in the melt tank and/or the extruder.
[0045] In an embodiment or in combination with any embodiment mentioned herein, the melt tank and/or the extruder may receive the waste plastic feed stream and heat the waste plastic via heating mechanisms in the melt tank and/or via the extrusion process in the extruder.
[0046] In an embodiment or in combination with any embodiment mentioned herein, the melt tank can include one or more continuously stirred tanks. When one or more rheology modification agents (e.g., solvents, depolymerization agents, plasticizers, and blending agents) are used in the liquification zone, such rheology modification agents can be added to and/or mixed with the waste plastic stream 32 in or prior to introduction into the melt tank.
[0047] In an embodiment or in combination with any embodiment mentioned herein, the interior space of the liquification vessel, where the plastic is heated, is maintained at a temperature of at least 200, at least 210, at least 220, at least 230, at least 240, at least 250, at least 260, at least 270, at least 280, at least 290, at least 300, at least 310, at least 320, at least 330, at least 340, at least 350, at least 360, at least 370, at least 380, at least 390, or at least 400 °C. Additionally, or in the alternative, the interior space of the liquification vessel may be maintained at a temperature of not more than 500, not more than 475, not more than 450, not more than 425, not more than 400, not more than 390, not more than 380, not more than 370, not more than 365, not more than 360, not more than 355, not more than 350, or not more than
345 °C. Generally, in one or more embodiments, the interior space of the liquification vessel may be maintained at a temperature ranging from 200 to 500 °C, 240 to 425 °C, 280 to 380 °C, or 320 to 350 °C.
[0048] In an embodiment or in combination with any embodiment mentioned herein, the liquification zone may optionally contain equipment for removing halogens from the waste plastic stream 32. When the waste plastic is heated in the liquification zone, halogen enriched gases can evolve. By disengaging the evolved halogen-enriched gasses from the liquified plastics, the concentration of halogens in the liquified plastic stream can be reduced. [0049] In an embodiment or in combination with any embodiment mentioned herein, dehalogenation can be promoted by sparging a stripping gas (e.g., steam) into the liquified plastics in the melt tank.
[0050] In an embodiment or in combination with any embodiment mentioned herein, the liquified plastic stream exiting the liquification zone can have a halogen content of less than 500, less than 400, less than 300, less than 200, less than 100, less than 50, less than 10, less than 5, less than 2, less than 1 , less than 0.5, or less than 0.1 ppmw.
[0051] In an embodiment or in combination with any embodiment mentioned herein, the halogen content of the liquified plastic stream exiting the liquification zone can be not more than 95, not more than 90, not more than 75, not more than 50, not more than 25, not more than 10, or not more than 5 percent by weight of the halogen content of the waste plastic stream 32 introduced into the liquification zone.
[0052] In an embodiment or in combination with any embodiment mentioned herein, the liquefied waste plastic stream 32 exiting the plastic liquification system may have a temperature of at least 200, at least 225, at least 250, at least 275, at least 300, at least 310, at least 320, at least 330, or at least 340 °C and/or less than 450, less than 425, less than 400, less than 375, or less than 350 °C.
[0053] As shown in FIG. 1 and described below in greater detail, at least a portion of the liquified plastic stream may be introduced into a downstream pyrolysis reactor 12 at a pyrolysis facility to produce a pyrolysis effluent 34, including pyrolysis oil and pyrolysis gas.
Pyrolysis
[0054] As shown in FIG. 1 , the chemical recycling facility 10 may comprise a pyrolysis facility, including a pyrolysis reactor 12. As used herein, the term “pyrolysis” refers to thermal decomposition of a feedstock of a biomass and/or a plastic material in solid or liquid form at elevated temperatures in an inert (i.e., substantially molecular oxygen free) atmosphere. A “pyrolysis facility” is a facility that includes all equipment, lines, and controls necessary to carry out pyrolysis of waste plastic and feedstocks derived therefrom. In certain embodiments, the pyrolysis facility can comprise the pyrolysis reactor 12 and, optionally, the plastic liquification zone and/or the separation zone.
[0055] As depicted in FIG. 1 , the liquified plastic stream may be introduced into a downstream pyrolysis reactor 12 at a pyrolysis facility so as to produce a pyrolysis effluent stream 34 and an optional pyrolysis residue stream.
[0056] In an embodiment or in combination with any embodiment mentioned herein the liquified plastic stream to the pyrolysis facility may be a PO-enriched stream of waste plastic. The liquified plastic stream introduced into the pyrolysis reactor 12 can be in the form of liquified plastic (e.g., liquified, melted, plasticized, depolymerized, or combinations thereof), plastic pellets or particulates, or a slurry thereof.
[0057] In general, the pyrolysis facility may include the plastic liquification zone, the pyrolysis reactor 12, the condenser 24 for separating the pyrolysis effluent stream 34 from the reactor, and the separator 26 for the pyrolysis oil stream (discussed below).
[0058] While in the pyrolysis reactor 12, at least a portion of the feed may be subjected to a pyrolysis reaction that produces a pyrolysis effluent comprising a pyrolysis oil, a pyrolysis gas, and a pyrolysis residue. Generally, the pyrolysis effluent stream 34 exiting the pyrolysis reactor 12 can be in the form of pyrolysis vapors that comprise the pyrolysis gas and uncondensed pyrolysis oil. As used herein, “pyrolysis vapor” refers to the uncondensed pyrolysis effluent that comprises the majority of the pyrolysis oil and the pyrolysis gas present in the pyrolysis effluent.
[0059] Pyrolysis is a process that involves the chemical and thermal decomposition of the introduced feed. Although all pyrolysis processes may be generally characterized by a reaction environment that is substantially free of oxygen, pyrolysis processes may be further defined, for example, by the pyrolysis reaction temperature within the reactor, the residence time in the pyrolysis reactor 12, the reactor type, the pressure within the pyrolysis reactor 12, and the presence or absence of pyrolysis catalysts.
[0060] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis reactor 12 can be, for example, a film reactor, a screw extruder, a tubular reactor, a tank, a stirred tank reactor, a riser reactor, a fixed bed reactor, a fluidized bed reactor, a rotary kiln, a vacuum reactor, a microwave reactor, or an autoclave. In various embodiments, the pyrolysis reactor 12 may comprise a film reactor, such as a falling film reactor or an up-flow film reactor.
[0061] In an embodiment or in combination with any embodiment mentioned herein, a lift gas and/or a feed gas may be used to introduce the feedstock into the pyrolysis reactor 12 and/or facilitate various reactions within the pyrolysis reactor 12. For instance, the lift gas and/or the feed gas may comprise, consist essentially of, or consist of nitrogen, carbon dioxide, and/or steam. The lift gas and/or feed gas may be added with the waste plastic stream 32 prior to introduction into the pyrolysis reactor 12 and/or may be added directly to the pyrolysis reactor 12. The lift gas and/or feed gas can include steam and/or a reducing gas such as hydrogen, carbon monoxide, and combinations thereof.
[0062] Furthermore, the temperature in the pyrolysis reactor 12 can be adjusted so as to facilitate the production of certain end products. In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis temperature in the pyrolysis reactor 12 can range from 325 to 1 ,100°C, 350 to 900°C, 350 to 700°C, 350 to 550°C, 350 to 475°C, 425 to 1 ,100°C, 425 to 800°C, 500 to 1 ,100°C, 500 to 800°C, 600 to 1 ,100°C, 600 to 800°C, 625 to 1 ,000°C, 700 to 1 ,000°C, or 625 to 800°C. Generally, in certain embodiments, the pyrolysis temperature in the pyrolysis reactor 12 can be greater than 625°C. Alternatively, in certain embodiments, the pyrolysis temperature in the pyrolysis reactor 12 can be less than 625°C.
[0063] In an embodiment or in combination with any embodiment mentioned herein, the residence times of the feedstocks within the pyrolysis reactor 12 can be at least 0.1 , at least 0.2, at least 0.3, at least 0.5, at least 1 , at least 1 .2, at least 1 .3, at least 2, at least 3, or at least 4 seconds. Alternatively, the residence times of the feedstocks within the pyrolysis reactor 12 can be at least 1 , at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 20, at least 30, at least 45, at least 60, at least 75, or at least 90 minutes. Additionally, or alternatively, the residence times of the feedstocks within the pyrolysis reactor 12 can be less than 6, less than 5, less than 4, less than 3, less than 2, less than 1 , or less than 0.5 hours. Furthermore, the residence times of the feedstocks within the pyrolysis reactor 12 can be less than 100, less than 90, less than 80, less than 70, less than 60, less than 50, less than 40, less than 30, less than 20, less than 10, less than 9, less than 8, less than 7, less than 6, less than 5, less than 4, less than 3, less than 2, or less than 1 seconds. More particularly, the residence times of the feedstocks within the pyrolysis reactor 12 can range from 0.1 to 10 seconds, 0.5 to 10 seconds, 30 minutes to 4 hours, or 30 minutes to 3 hours, or 1 hour to 3 hours, or 1 hour to 2 hours. [0064] In an embodiment or in combination with any embodiment mentioned herein, the pressure within the pyrolysis reactor 12 can be maintained at atmospheric pressure or within the range of 0.1 to 100 bar, or 0.1 to 60 bar, or 0.1 to 30 bar, or 0.1 to 10 bar, 0.2 to 1 .5 bar, or 0.3 to 1 .1 bar. As used herein, the term “bar” refers to gauge pressure, unless otherwise noted.
[0065] In an embodiment or in combination with any embodiment mentioned herein, a pyrolysis catalyst may be introduced into the liquified plastic stream prior to introduction into the pyrolysis reactor 12 and/or introduced directly into the pyrolysis reactor 12. The catalyst can be homogenous or heterogeneous and may include, for example, certain types of zeolites and other mesostructured catalysts. In some embodiments, the pyrolysis reaction may not be catalyzed (e.g., carried out in the absence of a pyrolysis catalyst), but may include a non-catalytic, heat-retaining inert additive, such as sand, in the reactor in order to facilitate the heat transfer. Such catalyst-free pyrolysis processes may be referred to as “thermal pyrolysis.” [0066] After exiting the pyrolysis reactor 12, the pyrolysis effluent may be separated into the pyrolysis oil stream and the pyrolysis gas stream in a separation system, such as the condenser 24 depicted in FIG. 1. Although not depicted in FIG. 1 , this condenser 24 can include various types of equipment including, but not limited to a filter system, a multistage separator, a condensation zone, and/or a quench tower. While in the condenser 24, the pyrolysis effluent, such as the pyrolysis vapors, may be cooled to condense the pyrolysis oil fraction originally present in the pyrolysis effluent stream. [0067] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, or at least 75 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors. Additionally, or alternatively, the pyrolysis effluent or pyrolysis vapors may comprise not more than 99, not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, or not more than 25 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors. As discussed above, the pyrolysis oil may be in the form of uncondensed vapors in the pyrolysis effluent upon exiting the heated reactor; however, these vapors may be subsequently condensed into the resulting pyrolysis oil. The pyrolysis effluent or pyrolysis vapors may comprise in the range of 20 to 99 weight percent, 25 to 80 weight percent, 30 to 85 weight percent, 30 to 80 weight percent, 30 to 75 weight percent, 30 to 70 weight percent, or 30 to 65 weight percent of the pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors.
[0068] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, or at least 80 weight percent of the pyrolysis gas, based on the total weight of the pyrolysis effluent or pyrolysis vapors. Additionally, or alternatively, the pyrolysis effluent or pyrolysis vapors may comprise not more than 99, not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, not more than 50, or not more than 45 weight percent of the pyrolysis gas, based on the total weight of the pyrolysis effluent or pyrolysis vapors. The pyrolysis effluent may comprise 1 to 90 weight percent, 10 to 85 weight percent, 15 to 85 weight percent, 20 to 80 weight percent, 25 to 80 weight percent, 30 to 75 weight percent, or 35 to 75 weight percent of the pyrolysis gas, based on the total weight of the stream.
[0069] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 12 may comprise at least 0.5, at least 1 , at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, or at least 10 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors. Additionally, or alternatively, the pyrolysis effluent may comprise not more than 60, not more than 50, not more than 40, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 9, not more than 8, not more than 7, not more than 6, or not more than 5 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors. The pyrolysis effluent may comprise in the range of 0.1 to 25 weight percent, 1 to 15 weight percent, 1 to 8 weight percent, or 1 to 5 weight percent of the pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapors. This pyrolysis residue may be removed from the pyrolysis reactor 12 (where it may form) and/or separated from the pyrolysis effluent in a downstream separator, such as the condenser 24.
[0070] The resulting pyrolysis oil stream and pyrolysis gas stream may be directly used in various downstream applications based on their formulations. The various characteristics and properties of the pyrolysis oil, pyrolysis gas, and pyrolysis residue are described below. It should be noted that, while all of the following characteristics and properties may be listed separately, it is envisioned that each of the following characteristics and/or properties of the pyrolysis gas, pyrolysis oil, and/or pyrolysis residue are not mutually exclusive and may be combined and present in any combination.
[0071] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil may predominantly comprise hydrocarbons having from 4 to 30 carbon atoms per molecule (e.g., C4 to C30 hydrocarbons). As used herein, the term “Cx” or “Cx hydrocarbon,” refers to a hydrocarbon compound including “x” total carbons per molecule, and encompasses all olefins, paraffins, aromatics, heterocyclic, and isomers having that number of carbon atoms. For example, each of normal, iso, and tert-butane and butene and butadiene molecules would fall under the general description “C4.” The pyrolysis oil may have a C4-C30 hydrocarbon content of at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent based on the total weight of the pyrolysis oil stream.
[0072] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil can predominantly comprise C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons. For example, the pyrolysis oil may comprise at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or at least 95 weight percent of C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons, based on the total weight of the pyrolysis oil stream.
[0073] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil may also include various amounts of diolefins and aromatics, depending on the pyrolysis reactor 12 conditions and whether a pyrolysis catalyst is employed. For example, the pyrolysis oil may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent of diolefins and/or aromatics, based on the total weight of the pyrolysis oil stream. Additionally, or alternatively, the pyrolysis oil may include not more than 90, not more than 80, not more than 70, not more than 60, not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, not more than 20, not more than 15, not more than 10, not more than 5, or not more than 1 weight percent of diolefins and/or aromatics, based on the total weight of the pyrolysis oil stream. As used herein, the term “aromatics” refers to the total amount (in weight) of any compounds containing an aromatic moiety, such as benzene, toluene, xylene, and styrene.
[0074] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil may have a mid-boiling point in the range of 75 to 250 °C, 90 to 225 °C, or 115 to 190 °C as measured according to ASTM D-5399. As used herein, “mid-boiling point” refers to the median boiling point temperature of the pyrolysis oil, where 50 percent by volume of the pyrolysis oil boils above the mid-boiling point and 50 percent by volume boils below the mid-boiling point.
[0075] In an embodiment or in combination with any embodiment mentioned herein, the boiling point range of the pyrolysis oil may be such that at least 90 percent of the pyrolysis oil boils off at a temperature of 250°C, of 280°C, of 290°C, of 300°C, or of 310°C, as measured according to ASTM D- 5399.
[0076] As noted above, the pyrolysis conditions, such as temperature, may be controlled so as to maximize the production of certain hydrocarbons and chemical compounds in the resulting pyrolysis gas and pyrolysis oil.
[0077] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis reaction can occur at temperatures of least 625°C. In such embodiments, the pyrolysis effluent, the pyrolysis vapors, and/or the pyrolysis oil derived from such pyrolysis reactions may comprise the following compounds (all of the following weight percentages are based on the total weight of the associated stream):
• at least 5, at least 10, at least 15, at least 20, at least 25, or at least 30 weight percent and/or not more than 95, not more than 90, not more than 85, or not more than 80 weight percent of benzene, based on the total weight of the stream; • at least 0.05, at least 0.1 , at least 0.5, or at least 1 weight percent and/or not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, or not more than 20 weight percent of ethyl benzene, based on the total weight of the stream;
• at least 0.5, at least 1 , at least 3, or at least 5 weight percent and/or not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, or not more than 50 weight percent of toluene, based on the total weight of the stream;
• at least 0.5, at least 1 , at least 3, or at least 5 weight percent and/or not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, or not more than 50 weight percent of xylene, based on the total weight of the stream;
• at least 0.5, at least 1 , at least 3, or at least 5 weight percent and/or not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, not more than 65, not more than 60, not more than 55, or not more than 50 weight percent of styrene, based on the total weight of the stream;
• at least 0.1 , at least 0.5, at least 1 , at least 3, or at least 5 weight percent and/or not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, or not more than 20 weight percent of cyclopentadiene, dicyclopentadiene, and/or their derivatives, based on the total weight of the stream; and/or
• at least 0.5, at least 1 , at least 3, at least 5, or at least 10 weight percent and/or not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, or not more than 20 weight percent of total diolefins, based on the total weight of the stream. [0078] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis reaction can occur at temperatures of less than 625°C. In such embodiments, the pyrolysis effluent, the pyrolysis vapors, and/or the pyrolysis oil derived from such pyrolysis reactions may comprise the following compounds (all of the following weight percentages are based on the total weight of the associated stream):
• at least 0.1 , at least 0.5, or at least 1 weight percent and/or not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, or not more than 20 weight percent of C1 -C8 compounds, based on the total weight of the stream;
• at least 0.1 , at least 0.5, or at least 1 weight percent and/or not more than 50, not more than 45, not more than 40, not more than 35, not more than 30, not more than 25, or not more than 20 weight percent of benzene, ethyl benzene, toluene, xylene, styrene, cyclopentadiene, dicyclopentadiene, and/or derivatives thereof, based on the total weight of the stream; and/or
• at least 5, at least 10, at least 15, at least 20, at least 25, or at least 30 weight percent and/or not more than 95, not more than 90, or not more than 85 weight percent of C15+ compounds, based on the total weight of the pyrolysis oil stream.
[0079] T urning to the pyrolysis gas, the pyrolysis gas can have a methane content in the range of 1 to 50 weight percent, 5 to 50 weight percent, or 15 to 45 weight percent, based on the total weight of the pyrolysis gas stream.
[0080] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis gas can have a C3 and/or C4 hydrocarbon content (including all hydrocarbons having 3 or 4 carbon atoms per molecule) in the range of 10 to 90 weight percent, 25 to 90 weight percent, or 25 to 80 weight percent, based on the total weight of the pyrolysis gas stream.
[0081] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis gas can have a combined ethylene and propylene content of at least 25, at least 40, at least 50, at least 60, at least 70, or at least 75 weight percent, based on the total weight of the pyrolysis gas stream.
[0082] Turning to the pyrolysis residue, in an embodiment or in combination with any embodiment mentioned herein, the pyrolysis residue comprises at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, or at least 85 weight percent of C20+ hydrocarbons based on the total weight of the pyrolysis residue. As used herein, “C20+ hydrocarbon” refers to hydrocarbon compounds containing at least 20 total carbons per molecule, and encompasses all olefins, paraffins, and isomers having that number of carbon atoms.
[0083] In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the pyrolysis gas stream and/or pyrolysis residue stream may be routed to one or more other chemical processing facilities, including, for example, the cracking facility. As shown in FIG. 1 , in some embodiments, at least a portion of the pyrolysis gas stream may be routed from the condenser 24 to the compressor system 18 of the cracking facility. The pyrolysis gas stream may be introduced into any stage of the downstream compressor 18.
[0084] As shown in FIG. 1 , at least a portion of the pyrolysis oil stream may be routed to a separation system (as shown as a separator 26 in FIG. 1) to thereby form an extract stream 28 and a raffinate stream 30. In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis oil stream may be separated into the extract stream 28 and the raffinate stream 30 in the separation system via: (i) a solvent extraction process, which can separate these two streams based on their relative solubilities; (ii) membrane separation; (iii) adsorption, or (iv) extractive distillation. In specific embodiments, the pyrolysis oil stream subjected to separation in the separation system may not undergo any hydroprocessing and/or hydrotreating prior to this separation step. Rather, in such embodiments, the pyrolysis oil stream may be immediately introduced into the separation system upon leaving the aforementioned condenser 24. [0085] Generally, the solvent extraction process exploits the different solubilities of the various components (e.g., aromatics and diolefins) of the pyrolysis oil stream in a solvent. The solvent extraction process generally involves placing the pyrolysis oil stream in contact with at least one extraction solvent that is either immiscible or only partially miscible with the pyrolysis oil stream. The solvent may be chosen so that it can preferentially dissolve or extract the desired components (e.g., aromatics and/or diolefins) from the pyrolysis oil stream. The two liquid phases that are then formed can be physically separated and the extract stream 28 (enriched in aromatics and/or diolefins) may be recovered and separated from the raffinate phase, usually by distillation. Solvent extraction may also be used to further separate out specific types of lighter aromatics (e.g., benzene) from heavier aromatics (e.g., toluene). Exemplary commercial solvent extraction systems that may be used as the separator 26 may include Sulfolane® by UQP, Udex™ by UOP, Tetra™ by UOP, Carom™ by UOP, Arosolvan® by Lurgi, Morphylex® by Krupp Kopper and IFP, and Formex® by Enichem.
[0086] An exemplary solvent extraction process and system 26 is depicted in FIG. 2. As shown in FIG. 2, the pyrolysis oil stream can be introduced into the extraction vessel 36, along with one or more extraction solvents, where the pyrolysis oil stream may flow in a countercurrent manner relative to the extraction solvents disclosed herein. As the pyrolysis oil stream flows through the extraction vessel 36, the aromatics and/or diolefins may be selectively dissolved in the extraction solvent. Consequently, as shown in FIG. 2, a raffinate stream 38, which is depleted in aromatics and/or diolefins (relative to the pyrolysis oil stream), may be removed from the overhead or near the top of the extraction vessel 36, washed in a water wash vessel 40, and then removed from the system. Meanwhile, the extract stream 42 from the bottom of the extraction vessel 36, which is enriched with aromatics and/or diolefins (relative to the pyrolysis oil stream), may be removed from the bottom of the extraction vessel 36 and further treated in a downstream distillation column 44. The resulting overhead stream from the distillation column 44 may be sent as a reflux stream 46 back to the extraction vessel 36, while the bottom stream 48 may be further treated in a solvent recovery vessel 50 so as to form an overhead stream comprising the extract stream and a bottom stream 54 with the recovered solvent, which may be recycled back to the extraction vessel 36. The overhead stream 52 may then be treated in a downstream separator 56 so as to form the extract stream, which may be removed for further processing and/or introduced back into the solvent recovery vessel 50. In an embodiment or in combination with any embodiment mentioned herein, the solvent extraction process may occur at temperatures in the range of 15 to 250 °C, 30 to 200 °C, or 40 to 175 °C.
[0087] Alternatively, as shown in FIG. 3, extractive distillation processes may be used to separate the pyrolysis oil stream into the raffinate stream 30 and extract stream 28. Generally, extractive distillation refers to processes in which a high-boiling solvent is added to a feed mixture (e.g., the pyrolysis oil stream) to alter the relative volatilities of the components to be separated. The solvent increases the difference between the volatilities because of the nonideal behavior of the mixture. The solvent may be withdrawn in the bottom (extract) product with the aromatics and/or diolefins, and solvent recovery can be accomplished via distillation. Extractive distillation has been favored for feedstocks that generally have a high aromatics content.
Exemplary commercial extractive distillation systems that may be used as the separator 26 include, for example, those by Glitsch, Krupp Koppers, and/or Lurgi. An exemplary extractive distillation process and system is depicted in FIG. 3.
[0088] As shown in FIG. 3, the extractive distillation process can involve feeding the pyrolysis oil stream and at least one extraction solvent to an extractive distillation column 58. The resulting raffinate stream 30 may be removed from the overhead of the extractive distillation column. Meanwhile, the bottom stream 60 from the column may then be introduced into a solvent recovery vessel 50, which can further separate and recover the extraction solvent from this bottoms stream. The recovered solvent 54 may be recycled back to the extractive distillation column. The overhead stream 52 may then be treated in a downstream separator so as to form the extract stream, which may be removed for further processing and/or introduced back into the solvent recovery vessel 50. In an embodiment or in combination with any embodiment mentioned herein, the extractive distillation process may occur at temperatures in the range of 15 to 350 °C, 30 to 325 °C, or 40 to 300 °C. [0089] Generally, in certain embodiments, the pyrolysis oil stream may be separated into the extract stream 28 and the raffinate stream 30 via a solvent extraction process or an extractive distillation process. The extraction solvents used may include, for example, sulfolane, water, N- formylmorpholine, tetrahydrofurfuryl alcohol (THFA), sulfolane, furfural, tetraethylene glycol, dimethylsulfoxide, N-methyl-2-pyrrolidone, or combinations thereof.
[0090] The separator 26 shown in FIG. 1 can include various types of equipment including, but not limited to, a filter system, a multistage separator, a distillation column, an extractive distillation column, a tank, a separatory funnel, a countercurrent distribution system, a membrane system, a Craig apparatus, a spray column, a centrifugal contractor, a thin layer extraction vessel, a pulsed column, a rotating disk contractor, a sieve tray extractor, a Kuhni column, and/or a multistage mixer-settler. In certain embodiments, the separator 26 in FIG. 1 can be a conventional Benzene-Toluene-Xylene (BTX) Unit, which is commonly used in the petrochemical industry. For example, the separator 26 in FIG. 1 can comprise a solvent extraction system comprising: (i) at least one extraction device (e.g., a rotating disk contractor, a sieve tray extractor, a vertical multistage mixer-settler, and/or a Kuhni column) and (ii) at least one distillation column in fluid communication with the extraction device. [0091] The separator system 26 depicted in FIG. 1 can be used to recover most of the aromatics and/or diolefins present in the pyrolysis oil stream.
[0092] In an embodiment or in combination with any embodiment mentioned herein, and as shown in FIG. 1 , at least a portion of the liquid products derived from the separator 20 in the cracking facility may also be introduced into the separation system 26 with the pyrolysis oil stream. These liquid products from the cracking facility may contain large amounts of aromatics, such as benzene, toluene, xylene, and styrenes, and diolefins, such as cyclopentadiene and dicyclopentadiene. Thus, in such embodiments, this separator 26 in the pyrolysis facility may separate a combined stream containing the pyrolysis oil stream and the liquid products stream from the cracking facility into the extract stream and the raffinate stream.
[0093] In an embodiment or in combination with any embodiment mentioned herein, the feed stream into the separator 26 may comprise at least 10, at least 25, at least 50, at least 75, at least 90, at least 95, or at least 99 weight percent of the pyrolysis oil stream, based on the total weight of the feed stream. Additionally, or in the alternative, the feed stream into the separator 26 may comprise not more than 99, not more than 90, not more than 80, not more than 70, not more than 60, not more than 50, not more than 40, not more than 30 weight percent of the pyrolysis oil stream, based on the total weight of the feed stream.
[0094] In an embodiment or in combination with any embodiment mentioned herein, the feed stream into the separator 26 may comprise at least 10, at least 25, at least 50, at least 75, at least 90, at least 95, or at least 99 weight percent of the liquid product stream from the cracking facility, based on the total weight of the feed stream. Additionally, or in the alternative, the feed stream into the separator 26 may comprise not more than 99, not more than 90, not more than 80, not more than 70, not more than 60, not more than 50, not more than 40, not more than 30 weight percent of the liquid product stream from the cracking facility, based on the total weight of the feed stream. [0095] As noted above, the extract stream 28 may be enriched in aromatics (e.g., benzene, toluene, ethyl benzene, styrene, and/or xylene) and diolefins (e.g., cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof), which have been derived from the pyrolysis oil stream.
[0096] In an embodiment or in combination with any embodiment mentioned herein, the extract stream 28 may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, or not more than 65 weight percent of one or more aromatics, based on the total weight of the stream. Exemplary aromatics may include benzene, ethyl benzene, toluene, xylene, styrene, and/or derivatives thereof.
[0097] In an embodiment or in combination with any embodiment mentioned herein, the extract stream 28 may comprise at least 0.01 , at least 0.05, at least 0.1 , at least 0.5, at least 1 , least 2, or least 3 weight percent and/or not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of one or more diolefins, based on the total weight of the stream. Exemplary diolefins may include cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof.
[0098] Although not depicted in FIG. 1 , the extract stream 28 may be subjected to further downstream separation, so as to recover specific diolefins and/or aromatics from the extract stream 28. For example, the diolefins, benzene, toluene, and/or xylene may be individually recovered from the extract stream 28 via a downstream solvent extraction process, an adsorption process, a membrane separation process, and/or an extract distillation process (described above). Additionally, or in the alternative, at least a portion of the extract stream 28 itself and/or the individual chemical components therein (e.g., the aromatics and/or diolefins) may be removed from the chemical recycling facility 10 and sold to downstream chemical processors. In yet other embodiments, at least a portion of the extract stream 28 itself and/or the individual chemical components therein (e.g., the aromatics and/or diolefins) may be subjected to further downstream processing to thereby form other chemical derivatives and/or polymers. For instance, at least a portion of the diolefins recovered from the extract stream 28 may be used to form hydrocarbons or other chemical derivatives.
[0099] In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the extract stream 28 may be separated into an aromatics stream and a diolefin stream. Any conventional separation technique may be used to separate the extract stream, such as extractive distillation, solvent extraction, or distillation. In such embodiments, the aromatics stream may be enriched in aromatics and depleted in diolefins (relative to the extract stream) and the diolefin stream may be enriched in diolefins and depleted in aromatics (relative to the extract stream).
Additionally, in certain embodiments, at least a portion of the aromatics stream and/or the diolefin stream may be sold to downstream chemical processors for downstream processing. For example, at least a portion of the aromatics stream and/or the diolefin stream may be subjected to downstream processing to form chemical derivatives, polymers, fuels, and/or other hydrocarbons.
[0100] Turning back to FIG. 1 , the raffinate stream 30 may be depleted in aromatics (e.g., benzene, toluene, ethyl benzene, styrene, and/or xylene) and diolefins (e.g., cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof), relative to the pyrolysis oil stream.
[0101] In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises not more than 50, not more than 40, not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of benzene, ethyl benzene, toluene, xylenes, styrene, and/or total diolefins, based on the total weight of the raffinate stream.
[0102] In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, or not more than 65 weight percent of cyclopentadiene and/or dicyclopentadiene, based on the total weight of the raffinate stream.
[0103] In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises not more than 50, not more than 40, not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of aromatics, such as benzene, ethyl benzene, toluene, xylenes, and/or styrene, based on the total weight of the raffinate stream.
[0104] In an embodiment or in combination with any embodiment mentioned herein, the raffinate stream 30 comprises not more than 50, not more than 40, not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of diolefins, such as cyclopentadiene, dicycloplentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof, based on the total weight of the raffinate stream.
[0105] As shown in FIG. 1 , at least a portion of the raffinate stream 30 may be subjected to further downstream treatment and processing in the cracking facility.
Cracking
[0106] In an embodiment or in combination with any embodiment mentioned herein, at least a portion of one or more streams from the pyrolysis facility, including the raffinate stream 30 and/or the pyrolysis gas stream, may be introduced into a cracking facility. As used herein, the term “cracking” refers to breaking down complex organic molecules into simpler molecules by the breaking of carbon-carbon bonds. A “cracking facility” is a facility that includes all equipment, lines, and controls necessary to carry out cracking of a feedstock derived from waste plastic. A cracking facility can include one or more cracker furnaces 14, a quench system 16 for cooling the cracked products, a compression system, and a downstream separation zone including equipment used to process the effluent of the cracker furnace(s) 14. As used herein, the terms “cracker” and “cracking” are used interchangeably. [0107] In general, the cracker facility may include a cracker furnace 14, a quench system 16, a compression system, and a separation zone downstream of the cracker furnace 14 for separating the furnace effluent into various end products, such as a recycle content olefin (r-olefin) stream. In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the raffinate stream 30 and/or the pyrolysis gas stream can be sent to the cracking facility. The raffinate stream 30 may be introduced into an inlet of the cracker furnace 14, while the pyrolysis gas stream can be introduced into a location upstream or downstream of the furnace. The effluent from the cracker furnace 14 may be separated into gas products and liquid products in the downstream separator, as shown in FIG. 1. When used, the raffinate stream 30 and/or pyrolysis gas stream may optionally be combined with a stream of cracker feed to form the feed stream to the cracking facility.
[0108] In some embodiments, the cracker feed stream can include a hydrocarbon feed other than the pyrolysis gas and the raffinate stream in an amount of from 5 to 95 weight percent, 10 to 90 weight percent, or 15 to 85 weight percent, based on the total weight of the cracker feed.
[0109] In an embodiment or in combination with any embodiment mentioned herein, the cracker facility may comprise a single cracking furnace, or it can have at least 2, or at least 3, or at least 4, or at least 5, or at least 6, or at least 7, or at least 8 or more cracking furnaces operated in parallel. Any one or each furnace(s) may be gas cracker, or a liquid cracker, or a split furnace.
[0110] The cracker feed stream, along with the raffinate stream and/or pyrolysis gas, may pass through the cracking furnace, wherein the hydrocarbon components therein are thermally cracked to form lighter hydrocarbons, including olefins such as ethylene, propylene, and/or butadiene. The residence time of the cracker stream in the furnace can be in the range of from 0.15 to 2 seconds, 0.20 to 1.75 seconds, or 0.25 to 1.5 seconds.
[0111] The temperature of the cracked olefin-containing effluent withdrawn from the furnace outlet can be in the range of from 730 to 900 °C, 750 to 875 °C, or 750 to 850 °C. [0112] In an embodiment or in combination with any embodiment mentioned herein, the olefin-containing gas products stream withdrawn from the separator in the cracking facility (as shown in FIG. 1) can comprise at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, or at least 90 weight percent of C2 to C4 olefins, based on the total weight of the olefin-containing effluent stream. The olefin-containing gas products stream may comprise predominantly ethylene, predominantly propylene, or predominantly ethylene and propylene, based on the total weight of the olefin-containing effluent stream.
[0113] Additionally, a liquid products stream, which is enriched in aromatics and diolefins, may be also recovered from the separator in the cracking facility as shown in FIG. 1 . For example, the liquid products stream derived from cracking facility may comprise at least 0.01 , at least 0.05, or at least 0.1 weight percent and/or not more than 30, not more than 20, not more than 15, not more than 10, not more than 5, not more than 4, not more than 3, not more than 2, not more than 1 , not more than 0.5, or not more than 0.1 weight percent of one or more diolefins, based on the total weight of the stream. Exemplary diolefins may include cyclopentadiene, dicyclopentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof.
[0114] In an embodiment or in combination with any embodiment mentioned herein, the liquid products stream derived from cracking facility may comprise at least 1 , at least 5, at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, or at least 40 weight percent and/or not more than 95, not more than 90, not more than 85, not more than 80, not more than 75, not more than 70, or not more than 65 weight percent of one or more aromatics, based on the total weight of the stream. Exemplary aromatics may include benzene, ethyl benzene, toluene, xylene, styrene, and/or derivatives thereof.
[0115] In an embodiment or in combination with any embodiment mentioned herein, when introduced into the cracker facility, the pyrolysis gas stream may be introduced into the inlet of the cracker furnace 14, or all or a portion of the pyrolysis gas stream may be introduced downstream of the furnace outlet, at a location upstream of or within the separation zone of the cracker facility. When introduced into or upstream of the separation zone, the pyrolysis gas can be introduced upstream of the last stage of compression in the compressor, or prior to the inlet of at least one fractionation column in a fractionation section of the separator.
[0116] Upon exiting the cracker furnace outlet, the olefin-containing effluent stream may be cooled rapidly (e.g., quenched) in the quench system 16 in order to prevent production of large amounts of undesirable by-products and to minimize fouling in downstream equipment.
[0117] In an embodiment or in combination with any embodiment mentioned herein, at least a portion of one or more of the above streams may be introduced into one or more of the facilities shown in FIG. 1 , while, in other embodiments, all or a portion of the streams withdrawn from the separation zone of the cracking facility may be routed to further separation and/or storage, transportation, sale, and/or use.
[0118] As noted above, at least a portion of the liquid products stream from the cracking facility may be routed to the separator in the pyrolysis facility, so as to recover the aromatics and diolefins from this stream.
Definitions
[0119] It should be understood that the following is not intended to be an exclusive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, when accompanying the use of a defined term in context.
[0120] As used herein, the terms “a,” “an,” and “the” mean one or more.
[0121] As used herein, the term “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination, B and C in combination; or A, B, and C in combination.
[0122] As used herein, the phrase “at least a portion” includes at least a portion and up to and including the entire amount or time period.
[0123] As used herein, the term “chemical recycling” refers to a waste plastic recycling process that includes a step of chemically converting waste plastic polymers into lower molecular weight polymers, oligomers, monomers, and/or non-polymeric molecules (e.g., hydrogen, carbon monoxide, methane, ethane, propane, ethylene, and propylene) that are useful by themselves and/or are useful as feedstocks to another chemical production process(es). [0124] As used herein, the term “chemical recycling facility” refers to a facility for producing a recycle content product via chemical recycling of waste plastic.
[0125] As used herein, the term “co-located” refers to the characteristic of at least two objects being situated on a common physical site, and/or within one mile of each other.
[0126] As used herein, the terms “comprising,” “comprises,” and “comprise” are open-ended transition terms used to transition from a subject recited before the term to one or more elements recited after the term, where the element or elements listed after the transition term are not necessarily the only elements that make up the subject.
[0127] As used herein, the term “cracking” refers to breaking down complex organic molecules into simpler molecules by the breaking of carboncarbon bonds.
[0128] As used herein, the term “depleted” refers to having a concentration (on a dry weight basis) of a specific component that is less than the concentration of that component in a reference material or stream.
[0129] As used herein, the term “directly derived” refers to having at least one physical component originating from waste plastic.
[0130] As used herein, the term “enriched” refers to having a concentration (on a dry weight basis) of a specific component that is greater than the concentration of that component in a reference material or stream. [0131] As used herein, the term “halide” refers to a composition comprising a halogen atom bearing a negative charge (i.e., a halide ion).
[0132] As used herein, the term “halogen” or “halogens” refers to organic or inorganic compounds, ionic, or elemental species comprising at least one halogen atom.
[0133] As used herein, the terms “having,” “has,” and “have” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.
[0134] As used herein, the terms “including,” “include,” and “included” have the same open-ended meaning as “comprising,” “comprises,” and “comprise” provided above.
[0135] As used herein, the term “indirectly derived” refers to having an assigned recycle content i) that is attributable to waste plastic, but ii) that is not based on having a physical component originating from waste plastic. [0136] As used herein, the term “isolated” refers to the characteristic of an object or objects being by itself or themselves and separate from other materials, in motion or static.
[0137] As used herein, the terms “mixed plastic waste” and “MPW” refer to a mixture of at least two types of waste plastics including, but not limited to the following plastic types: polyethylene terephthalate (PET), one or more polyolefins (PO), and polyvinylchloride (PVC).
[0138] As used herein, the term “overhead” refers to the physical location of a structure that is above a maximum elevation of quantity of particulate plastic solids within an enclosed structure.
[0139] As used herein, the term “partially processed waste plastic” means waste plastic that has been subjected to at least on automated or mechanized sorting, washing, or comminuted step or process. Partially processed waste plastics may originate from, for example, municipal recycling facilities (MRFs) or reclaimers. When partially processed waste plastic is provided to the chemical recycling facility, one or more preprocessing steps may me skipped.
[0140] As used herein, the term “physical recycling” (also known as “mechanical recycling”) refers to a waste plastic recycling process that includes a step of melting waste plastic and forming the molten plastic into a new intermediate product (e.g., pellets or sheets) and/or a new end product (e.g., bottles). Generally, physical recycling does not substantially change the chemical structure of the plastic, although some degradation is possible.
[0141] As used herein, the term “plastic” may include any organic synthetic polymers that are solid at 25°C and 1 atmosphere of pressure.
[0142] As used herein, the term “predominantly” means more than 50 percent by weight. For example, a predominantly propane stream, composition, feedstock, or product is a stream, composition, feedstock, or product that contains more than 50 weight percent propane.
[0143] As used herein, the term “preprocessing” refers to preparing waste plastic for chemical recycling using one or more of the following steps: (i) comminuting, (ii) particulating, (iii) washing, (iv) drying, and/or (v) separating.
[0144] As used herein, the term “pyrolysis” refers to thermal decomposition of a feedstock of a biomass and/or a plastic material in solid or liquid form at elevated temperatures in an inert (i.e., substantially molecular oxygen free) atmosphere.
[0145] As used herein, the term “pyrolysis char” refers to a carbon- containing composition obtained from pyrolysis that is solid at 200°C and 1 atm.
[0146] As used herein, the terms “pyrolysis gas” and “pygas” refer to a composition obtained from pyrolysis that is gaseous at 25°C at 1 atm.
[0147] As used herein, the term “pyrolysis heavy waxes” refers to C20+ hydrocarbons obtained from pyrolysis that are not pyrolysis char, pyrolysis gas, or pyrolysis oil.
[0148] As used herein, the terms “pyrolysis oil” or “pyoil” refers to a composition obtained from pyrolysis that is liquid at 25°C and 1 atm.
[0149] As used herein, the term “pyrolysis residue” refers to a composition obtained from pyrolysis that is not pyrolysis gas or pyrolysis oil and that comprises predominantly pyrolysis char and pyrolysis heavy waxes. [0150] As used herein, the terms “recycle content” and “r-content” refer to being or comprising a composition that is directly and/or indirectly derived from waste plastic.
[0151] As used herein, the terms “r-pyrolysis gas” or “r-pygas” refer to being or comprising a pyrolysis gas that is directly and/or indirectly derived from waste plastic.
[0152] As used herein, the terms “r-pyrolysis oil” or “r-pyoil” refer to being or comprising a pyrolysis oil that is directly and/or indirectly derived from waste plastic.
[0153] As used herein, the terms “waste plastic” and “plastic waste” refer to used, scrap, and/or discarded plastic materials. The waste plastic fed to the chemical recycling facility may be unprocessed or partially processed.
[0154] As used herein, the term “unprocessed waste plastic” means waste plastic that has not be subjected to any automated or mechanized sorting, washing, or comminuting. Examples of unprocessed waste plastic include waste plastic collected from household curbside plastic recycling bins or shared community plastic recycling containers.
[0155] As used herein, “downstream” means a target unit operation, vessel, or equipment that: a. is in fluid (liquid or gas) communication, or in piping communication, with an outlet stream from the radiant section of a cracker furnace, optionally through one or more intermediate unit operations, vessels, or equipment, or b. was in fluid (liquid or gas) communication, or in piping communication, with an outlet stream from the radiant section of a cracker furnace, optionally through one or more intermediate unit operations, vessels, or equipment, provided that the target unit operation, vessel, or equipment remains within the battery limits of the cracker facility (which includes the furnace and all associated downstream separation equipment).
CLAIMS NOT LIMITED TO DISCLOSED EMBODIMENTS
[0156] When a numerical sequence is indicated, it is to be understood that each number is modified the same as the first number or last number in the numerical sequence or in the sentence, e.g., each number is “at least,” or “up to” or “not more than” as the case may be; and each number is in an “or” relationship. For example, “at least 10, 20, 30, 40, 50, 75 wt.%...” means the same as “at least 10 wt.%, or at least 20 wt.%, or at least 30 wt.%, or at least 40 wt.%, or at least 50 wt.%, or at least 75 wt.%,” etc.; and “not more than 90 wt.%, 85, 70, 60...” means the same as “not more than 90 wt.%, or not more than 85 wt.%, or not more than 70 wt.%....” etc.; and “at least 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9% or 10% by weight...” means the same as “ at least 1 wt.%, or at least 2 wt.%, or at least 3 wt.% ...” etc.; and “at least 5, 10, 15, 20 and/or not more than 99, 95, 90 weight percent” means the same as “at least 5 wt.%, or at least 10 wt.%, or at least 15 wt.% or at least 20 wt.% and/or not more than 99 wt.%, or not more than 95 wt.%, or not more than 90 weight percent...” etc.
[0157] The preferred forms of the invention described above are to be used as illustration only and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention.
[0158] The inventors hereby state their intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any apparatus not materially departing from but outside the literal scope of the invention as set forth in the following claims.

Claims

What is claimed is -
1 . A chemical recycling process comprising:
(a) thermally pyrolyzing waste plastic to produce a pyrolysis oil stream;
(b) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins relative to the pyrolysis oil stream and the extract stream is enriched in aromatics and/or diolefins relative to the pyrolysis oil stream; and
(c) introducing at least a portion of the raffinate stream into a cracker furnace.
2. The process according to claim 1 , further comprising recovering the aromatics and/or the diolefins from the extract stream.
3. The process according to claim 1 , further comprising producing one or more hydrocarbons with at least a portion of the diolefins from the extract stream.
4. The process according to claim 1 , further comprising producing one or more fuels with at least a portion of the aromatics from the extract stream.
5. The process according to claim 1 , wherein the raffinate stream comprises not more than 20 weight percent of benzene, ethyl benzene, toluene, xylenes, styrene, and diolefins, based on the total weight of the raffinate stream.
6. The process according to claim 1 , wherein the raffinate stream comprises not more than 20 weight percent of total diolefins, based on the total weight of the raffinate stream.
7. The process according to claim 1 , wherein the extract stream comprises at least 20 weight percent of benzene, ethyl benzene, toluene, xylene, and styrene, based on the total weight of the extract stream; and not more than 20 weight percent of cyclopentadiene, dicycloplentadiene, pentadiene, hexadiene, cyclohexadiene, and/or derivatives thereof based on the total weight of the extract stream.
8. The process according to claim 1 , wherein the separating of step (b) comprises solvent extraction.
9. The process according to claim 1 , wherein the thermally pyrolyzing of step (a) occurs in the substantial absence of a catalyst material at temperature of at least 625°C.
10. A chemical recycling process comprising:
(a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent;
(b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream;
(c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins relative to the pyrolysis oil stream and the extract stream is enriched in aromatics and/or diolefins relative to the pyrolysis oil stream;
(d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed;
(e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; (f) compressing at least a portion of the cracked product in at least one compressor to form a compressed product; and
(g) separating at least one hydrocarbon from the compressed product to thereby form a recycle content hydrocarbon stream. 1. The process according to claim 10, wherein the raffinate stream is depleted in aromatics and diolefins relative to the pyrolysis oil stream and the extract stream is enriched in aromatics and diolefins relative to the pyrolysis oil stream. 2. The process according to claim 10, wherein the separating of step
(c) comprises solvent extraction. 3. The process according to claim 10, wherein the thermally pyrolyzing of step (a) occurs in the substantial absence of a catalyst material. 4. The process according to claim 10, wherein the pyrolysis oil stream comprises at least 10 weight percent of benzene, based on the total weight of the pyrolysis oil stream. 5. A chemical recycling process comprising:
(a) thermally pyrolyzing waste plastic to produce a pyrolysis effluent;
(b) condensing at least a portion of the pyrolysis effluent to thereby form a pyrolysis oil stream and a pyrolysis gas stream;
(c) separating at least a portion of the pyrolysis oil stream into a raffinate stream and an extract stream, wherein the raffinate stream is depleted in aromatics and/or diolefins and the extract stream is enriched in aromatics and/or diolefins;
(d) combining at least a portion of the raffinate stream with a cracker feed to form a combined cracker feed;
(e) cracking at least a portion of the combined cracker feed in a cracker furnace to form a cracked product; and (f) subjecting at least a portion of the extract stream to a chemical process so as to synthesize a chemical derivative and/or a polymer therefrom. 16. The process according to claim 15, wherein the pyrolysis oil stream comprises at least 5 weight percent of total diolefins based on the total weight of the pyrolysis oil stream.
17. The process according to claim 15, wherein the thermally pyrolyzing of step (a) occurs in a pyrolysis reactor within a pyrolysis facility and the cracker furnace is located within a cracker facility, wherein the pyrolysis facility and the cracker facility are co-located.
PCT/US2023/064372 2022-03-17 2023-03-15 Recovery of valuable chemical products from recycle content pyrolysis oil WO2023178132A1 (en)

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