Recovery of heat from low pressure waste streams

Abstract

It has been found that thermal energy previously lost due to evacuation can be captured from a typical waste stream, such as a flue gas stream. More specifically, it has been found that residual thermal energy from various waste streams in a chemical recovery facility can be used to preheat a waste plastic stream and provide heat for waste plastic pyrolysis. Thus, the pyrolysis methods and systems described herein enable lower carbon footprint to be obtained.

Description

Background Art

[0001] Pyrolysis of waste plastics plays a role in a variety of chemical recycling technologies. Pyrolysis of waste plastics produces heavy components (e.g., wax, tar, and coke), as well as recycled component pyrolysis oil (r-pyrolysis oil (r-pyoil)) and recycled component pyrolysis gas (r-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 r-pyrolysis oil and r-pyrolysis gas as possible to downstream processing facilities to be used as raw materials for forming other recycled component products (e.g., olefins, paraffins, etc.).

[0002] However, the combustion of fossil fuels is usually used to provide heat for melting the waste plastics for pyrolysis reaction, and to provide heat for the pyrolysis reaction itself. Therefore, this combustion of fossil fuels will increase CO2 emissions. In other words, the current methods for melting waste plastics and pyrolysis of waste plastics usually require the combustion of fossil fuels, which can adversely affect the carbon footprint of chemical recycling facilities. Therefore, a thermal treatment scheme that provides a lower carbon footprint for pyrolysis of waste plastics is needed. Summary of the invention

[0003] In one aspect, the present technology relates to a chemical recovery method. Generally, the method includes: (a) liquefying at least a portion of the waste plastic in a liquefaction system to form liquefied waste plastic; (b) pyrolyzing at least a portion of the liquefied waste plastic to produce a pyrolysis effluent; and (c) preheating at least a portion of the initial stream with a fluid energy source. In addition, the initial stream contains one or more of the following items: (i) waste plastic subjected to liquefaction of step (a), (ii) a combustion fuel stream for generating heat for liquefaction of step (a) or pyrolysis of step (b), or (iii) a combustion air stream for generating heat for liquefaction of step (a) or pyrolysis of step (b). In addition, the fluid energy source has a temperature in the range of 80°C to 260°C.

[0004] In one aspect, the present technology relates to a chemical recovery method. Generally, the method includes: (a) liquefying at least a portion of the waste plastic in a liquefaction system to form liquefied waste plastic; (b) pyrolyzing at least a portion of the liquefied waste plastic to produce a pyrolysis effluent; (c) preheating at least a portion of the initial stream with a flue gas stream to form a cooled flue gas stream; and (d) recovering a carbon dioxide stream from at least a portion of the cooled flue gas stream. In addition, the initial stream contains one or more of the following items: (i) waste plastic subjected to liquefaction in step (a), (ii) a combustion fuel stream for generating heat for liquefaction in step (a) or pyrolysis in step (b), or (iii) a combustion air stream for generating heat for liquefaction in step (a) or pyrolysis in step (b).

[0005] In one aspect, the present technology relates to a chemical recovery method. Generally, the method includes: (a) liquefying at least a portion of the waste plastic in a liquefaction system to form liquefied waste plastic; (b) pyrolyzing at least a portion of the liquefied waste plastic to produce a pyrolysis effluent and a pyrolysis flue gas; (c) cracking at least a portion of the pyrolysis effluent in a cracking furnace to form cracked products and cracked flue gas; (d) quenching at least a portion of the cracked products to form a quenched product stream and a quenched fluid stream; (e) compressing at least a portion of the quenched product stream to form a compressed product stream and a residual steam stream; (f) separating at least a portion of the compressed product stream to form a recovered component hydrocarbon stream; (g) generating a secondary steam stream, wherein the generating also forms a combustion flue gas; and (h) preheating at least a portion of the initial stream with at least a portion of the pyrolysis flue gas, cracker flue gas, quenched fluid stream, residual steam stream and / or combustion flue gas. In addition, the initial stream comprises one or more of the following: (i) waste plastics subjected to liquefaction in step (a); (ii) a combustion fuel stream for generating heat for liquefaction in step (a), pyrolysis in step (b), cracking in step (c) and / or generation in step (g); or (iii) a combustion air stream for generating heat for liquefaction in step (a), pyrolysis in step (b), cracking in step (c) and / or generation in step (g).

[0006] In one aspect, the present technology relates to a chemical recovery method. Generally, the method includes: (a) providing a waste stream that is undergoing or is otherwise to be emptied, wherein the waste stream originates from a pyrolysis facility and / or a cracking facility and has a temperature in the range of 80°C to 260°C; and (b) preheating at least a portion of an initial stream with the waste stream. In addition, the initial stream includes one or more of the following: (i) solid waste plastic feedstock that is subjected to liquefaction, (ii) combustion fuel for generating heat for the pyrolysis facility and / or the cracking facility, or (iii) a combustion air stream for generating heat for the pyrolysis facility and / or the cracking facility. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 is a block flow diagram illustrating the main steps of a method and facility for chemically recycling waste plastics and reusing heat from various flue gas streams according to an embodiment of the present technology. DETAILED DESCRIPTION

[0008] We have discovered that heat energy previously lost to evacuation can be captured from waste streams such as flue gas streams. More specifically, we have discovered that heat energy from these waste streams can be used to preheat waste plastic streams and provide heat for waste plastic pyrolysis. Thus, the pyrolysis methods and systems described herein can achieve a lower carbon footprint.

[0009] the following Figure 1An exemplary chemical recycling facility 10 is depicted that includes a pyrolysis facility (e.g., a plastic liquefaction system 12 and a pyrolysis reactor 14) and a cracking facility (e.g., a cracking furnace 16, a quenching system 18, a compression system 20, and a separator 22). Figure 1 As shown, the chemical recovery facility 10 may also contain a waste plastic source 24 and a CO2 purification system 26 for recovering CO2 from at least a portion of the cooled waste stream. As described above, the chemical recovery facility 10 described herein is capable of recovering thermal energy from a variety of different waste streams that are typically reserved for venting, such as flue gas streams from the liquefaction system 12, the pyrolysis reactor 14, the cracking furnace 16, and / or the utility boiler 40; oil and / or water streams from the quench system 18; and / or waste steam streams from the quench system 18, the compressor 20, and / or the separator 22. Figure 1 As depicted, at least a portion of the heat energy from these waste streams can be used to preheat: (i) the waste plastic prior to pyrolysis reaction, (ii) the combustion fuel prior to combustion, and / or (iii) the combustion air prior to combustion. It should be understood that Figure 1 An exemplary embodiment of the present technology is depicted. Figure 1 Certain features described in and / or additional features described elsewhere herein may be added to Figure 1 In the system depicted in . The individual method steps will be described in more detail below.

[0010] Integrated Chemical Recovery Facility

[0011] Now turn to Figure 1 , showing the main steps of a method for chemically recycling waste plastics in a chemical recycling facility 10. The chemical recycling method and facility as described herein can be used to convert waste plastics into recycled content products or chemical intermediates for forming various end-use materials. The waste plastics fed to the chemical recycling facility / process can be mixed plastic waste (MPW), pre-sorted waste plastics and / or pre-treated waste plastics. Figure 1 As shown, waste plastic feed stream 28 may originate from a waste plastic source 24, which may include a waste plastic pre-processing facility.

[0012] In an embodiment or in combination with any embodiment mentioned herein, the chemical recycling facility 10 can be a commercial scale facility capable of processing large quantities 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 a year.

[0013] In an embodiment or in combination with any embodiment mentioned herein, Figure 1Two or more of the facilities shown, such as the pyrolysis facility (e.g., pyrolysis reactor 14, waste plastic source 24, and plastic liquefaction system 12) and the cracking facility (e.g., cracking furnace 16, quenching system 18, compressor system 20, and separator 22), may be co-located with each other. As used herein, the term "co-located" refers to facilities where two facilities share at least a portion of a facility that processes a stream and / or supports equipment or service providers. Figure 1 When two or more of the facilities shown are co-located, the facilities may meet at least one of the following criteria (i) to (v): (i) the facilities share at least one non-residential utility service; (ii) the facilities share at least one service fleet; (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 pipeline configured to transport at least one process material (e.g., solids, liquids, and / or gases fed to, used by, or generated in the facilities) from one facility to another; and (v) the facilities are within 40 miles, within 35 miles, within 30 miles, within 20 miles, within 15 miles, within 12 miles, within 10 miles, within 8 miles, within 5 miles, within 2 miles, or within 1 mile of each other as measured from their geographic centers. At least one, at least two, at least three, at least four, or all of the above statements (i) to (v) may be met.

[0014] With respect to (i), examples of suitable utility services include, but are not limited to, steam systems (cogeneration and distribution systems), cooling water systems, heat transfer fluid systems, plant or instrument air systems, nitrogen systems, hydrogen systems, non-residential power generation and distribution (including distribution above 8000V), non-residential wastewater / sewer systems, storage facilities, transportation pipelines, flare systems, and combinations thereof.

[0015] With respect to (ii), examples of service teams and facilities include, but are not limited to, emergency service personnel (fire and / or medical), third-party vendors, state or local government oversight groups, and combinations thereof. Government oversight groups may include, for example, regulatory or environmental agencies, as well as municipal and tax agencies at the city, county, and state levels.

[0016] With respect to (iii), the boundary may be, for example, a fence line, a property line, a gate, or a common boundary with at least one boundary of land or facilities owned by a third party.

[0017] Regarding (iv), the pipeline may be a fluid pipeline that transports gas, liquid, solid / liquid mixture (e.g., slurry), solid / gas mixture (e.g., pneumatic conveying), solid / liquid / gas mixture or solid (e.g., belt conveying). In some cases, two units may share one or more pipelines selected from the above list.

[0018] Turn again Figure 1 , a waste plastic (which may be mixed plastic waste (MPW)) stream may be introduced into a chemical recycling facility 10 from a waste plastic source 24. As used herein, the terms "waste plastic" and "plastic waste" refer to used, discarded and / or discarded plastic materials, such as plastic materials that are typically sent to landfills. The waste plastic stream fed into the chemical recycling facility 10 may include untreated or partially treated waste plastics. As used herein, the term "untreated waste plastic" means waste plastics that have not yet been sorted, washed or shredded by any automation or mechanization. Examples of untreated waste plastics include waste plastics collected from household curbside plastic recycling bins or shared community plastic recycling containers. Partially processed waste plastics may originate from, for example, a municipal recycling facility (MRF) or a reclaimer. In certain embodiments, waste plastics may include at least one of post-industrial (or pre-consumer) plastics and / or post-consumer plastics.

[0019] In an embodiment or in combination with any of the embodiments mentioned herein, the mixed plastic waste (MPW) comprises at least two different types of plastics.

[0020] In an embodiment or in combination with any of the embodiments mentioned herein, all or a portion of the MPW in the waste plastic stream may originate from a municipal recycling facility (MRF).

[0021] In an embodiment or in combination with any of the embodiments mentioned herein, all or a portion of the MPW in the waste plastic stream may originate from a regenerator facility.

[0022] Examples of suitable waste plastics may include, but are not limited to, polyolefins (PO), aromatic and aliphatic polyesters, polyvinyl chloride (PVC), polystyrene, cellulose esters, polytetrafluoroethylene, acrylonitrile-butadiene-styrene (ABS), cellulosics, epoxy derivatives, polyamides, phenolic resins, polyacetals, polycarbonates, polyphenylene-based alloys, poly(methyl methacrylate), styrene-containing polymers, polyurethanes, vinyl polymers, styrene acrylonitrile, and urea-containing polymers and melamine.

[0023] 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, cross-linked polyethylene, amorphous polyolefins, and copolymers of any of the foregoing polyolefins.

[0024] Examples of polyesters may include those having repeating aromatic or cyclic units, such as those containing repeating terephthalate, isophthalate or naphthalate units, such as PET, modified PET and PEN, or those containing repeating furanoate repeating units. As used herein, "PET" or "polyethylene terephthalate" refers to homopolymers of polyethylene terephthalate, or polyethylene terephthalate modified with one or more acid and / or glycol modifiers and / or containing residues or moieties 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-propylene glycol and / or neopentyl glycol (NPG).

[0025] In an embodiment or in combination with any of the embodiments mentioned herein, the waste plastic stream comprises at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, at least 95 wt%, or at least 99 wt% of one or more polyolefins, based on the total weight of the stream. Alternatively or additionally, the waste plastic stream comprises no more than 99.9 wt%, no more than 99 wt%, no more than 97 wt%, no more than 92 wt%, no more than 90 wt%, no more than 85 wt%, no more than 80 wt%, no more than 75 wt%, no more than 70 wt%, no more than 65 wt%, no more than 60 wt%, no more than 55 wt%, no more than 50 wt%, no more than 45 wt%, no more than 40 wt%, no more than 35 wt%, no more than 30 wt%, no more than 25 wt%, no more than 20 wt%, no more than 15 wt%, no more than 10 wt%, or no more than 5 wt% of one or more polyolefins, based on the total weight of the stream.

[0026] In one embodiment or in combination with any of the mentioned embodiments, the waste plastic stream comprises no more than 20 wt%, no more than 15 wt%, no more than 12 wt%, no more than 10 wt%, no more than 8 wt%, no more than 6 wt%, no more than 5 wt%, no more than 4 wt%, no more than 3 wt%, no more than 2 wt%, or no more than 1 wt% polyester, based on the total weight of the stream.

[0027] In one embodiment or with any embodiment combination mentioned, based on the gross weight of stream, the waste plastic stream comprises the biowaste material that is no more than 20 % by weight, no more than 15 % by weight, no more than 12 % by weight, no more than 10 % by weight, no more than 8 % by weight, no more than 6 % by weight, no more than 5 % by weight, no more than 4 % by weight, no more than 3 % by weight, no more than 2 % by weight or no more than 1 % by weight.As used herein, term " biowaste " refers to the material deriving from living organism or organic source.Exemplary biowaste material includes but is not limited to cotton, timber, sawdust, food scraps, animal and animal parts, plant and plant parts and fertilizer.

[0028] In an embodiment or in combination with any embodiment mentioned herein, the waste plastic stream may contain no more than 10 wt%, no more than 5 wt%, no more than 4 wt%, no more than 3 wt%, no more than 2 wt%, no more than 1 wt%, no more than 0.75 wt%, or no more than 0.5 wt% polyvinyl chloride (PVC), based on the total weight of the stream.

[0029] The following will now be described in further detail starting with the optional pre-treatment facilities of the waste plastic source 24. Figure 1 The general configuration and operation of each facility that may be present in chemical recovery facility 10 is shown.

[0030] Optional plastic pretreatment

[0031] like Figure 1 As shown, untreated, partially treated and / or treated waste plastics (such as mixed plastic waste (MPW)) may first be introduced into the chemical recovery facility 10 via a waste plastic stream from a waste plastic source 24. As described above, the waste plastic source 24 may include an optional pretreatment facility that can prepare the waste plastic feedstock for the downstream recycling process. While in the optional pretreatment facility, the waste plastic feedstock may undergo one or more pretreatment steps to prepare it for chemical recovery. As used herein, the term "pretreatment facility" refers to a facility that includes all equipment, pipelines, and control devices required for pretreatment of waste plastics. The pretreatment facility as described herein may use any suitable method to prepare the waste plastics for chemical recovery using one or more of the following steps, which will be described in further detail below. Optionally, in certain embodiments, the waste plastic source 24 does not contain a pretreatment facility, and the waste plastic stream does not undergo any pretreatment before any downstream chemical recovery steps described herein.

[0032] In an embodiment or in combination with any of the embodiments mentioned herein, the pre-treatment facility of the waste plastic source 24 can include at least one separation step or zone. The separation step or zone can be configured to separate the waste plastic stream into two or more streams enriched in certain types of plastics. This 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 used to separate waste plastics into two or more streams enriched in certain types of plastics, such as, for example, a PET-rich stream and a PO-rich stream. Examples of suitable types of separation include mechanical separation and density separation, the latter of which may include float-sink separation and / or centrifugal density separation. As used herein, the term "float-sink separation" refers to a density separation process in which 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 in which the separation of materials is primarily caused by centrifugal force.

[0034] Reference again Figure 1 , the waste plastic stream can be introduced into one or more downstream processing facilities within the chemical recycling facility 10 (or undergo one or more downstream processing steps). In an embodiment or in combination with any of the embodiments mentioned herein, at least a portion of the waste plastic stream can be introduced directly or indirectly into the plastic liquefaction system 12 within or outside the waste plastic source 24. Additional details of each step according to one or more embodiments of the present technology, as well as the overall integration of each of these steps or facilities with one or more of the other steps or facilities, will be discussed in further detail below.

[0035] Liquefaction / Dehalogenation

[0036] like Figure 1 As shown, the waste plastic stream may be introduced into the plastic liquefaction system 12 prior to introduction into the pyrolysis reactor 14. As used herein, the term "liquefaction" system refers to a chemical processing zone or step where at least a portion of the incoming plastic is liquefied. Figure 1 The step of liquefying the plastic may include chemical liquefaction, physical liquefaction, or a combination thereof. Exemplary methods of liquefying the plastic introduced into the liquefaction system 12 may include: (i) heating / melting; (ii) dissolving in a solvent; (iii) depolymerization; (iv) plasticization; and combinations thereof. In addition, one or more of options (i) to (iv) may also be accompanied by the addition of a blending agent or liquefier to help promote the liquefaction of the polymer material (reducing viscosity). Therefore, various rheology modifiers (e.g., solvents, depolymerizers, plasticizers, and blending agents) may be used to enhance the flow and / or dispersibility of the liquefied waste plastic.

[0037] When added to the liquefaction system 12, at least 50% by weight, at least 55% by weight, at least 60% by weight, at least 65% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, at least 85% by weight, at least 90% by weight, at least 95% by weight, or at least 99% by weight of the plastics originally present in the waste plastics stream will experience a decrease in viscosity. In some cases, the decrease in viscosity can be promoted by heating (e.g., adding steam that directly or indirectly contacts the plastics), while in other cases, the decrease in viscosity can be promoted by combining the plastics with a solvent that can dissolve the plastics. Examples of suitable solvents may include, but are not limited to, alcohols (such as methanol or ethanol), glycols (such as ethylene glycol, diethylene glycol, triethylene glycol, neopentyl glycol, cyclohexanedimethanol), glycerol, pyrolysis oil, motor oil, and water. This dissolving solvent can be added directly to the liquefaction vessel in the liquefaction system 12, or it can be pre-combined with one or more streams (including the waste plastics stream) fed to the liquefaction system 12.

[0038] In an embodiment or in combination with any of the embodiments mentioned herein, the dissolution solvent may include a stream withdrawn from one or more other facilities within the chemical recovery facility 10. For example, the solvent may include a stream withdrawn from the pyrolysis reactor 14 and / or the separation zone. In certain embodiments, the dissolution solvent may be or include pyrolysis oil.

[0039] In some cases, waste plastics can be depolymerized so that, for example, the number average chain length of the plastic is reduced by contact with a depolymerizing agent. In an embodiment or in combination with any embodiment mentioned herein, at least one of the previously listed solvents can be used as a depolymerizing agent, while in one or more other embodiments, the depolymerizing agent can include an organic acid (e.g., acetic acid, citric acid, butyric acid, formic acid, lactic acid, oleic acid, oxalic acid, stearic acid, tartaric acid and / or uric acid) or an inorganic acid, such as sulfuric acid (for polyolefins). The depolymerizing agent can reduce the melting point and / or viscosity of the polymer by reducing the number average chain length of the polymer.

[0040] Alternatively or additionally, a plasticizer may be used in the liquefaction system 12 to reduce the viscosity of the plastic. Plasticizers for polyethylene include, for example, dioctyl phthalate, dioctyl terephthalate, glyceryl tribenzoate, polyethylene glycols with molecular weights up to 8,000 Daltons, sunflower oil, paraffins with molecular weights of 400 to 1,000 Daltons, paraffin oils, mineral oils, glycerine, EPDM, and EVA. Plasticizers for polypropylene include, for example, dioctyl sebacate, paraffin oils, isooctyl resinate, plasticizing oils (Drakeol 34), naphthenic and aromatic process oils, and glycerine. Plasticizers for polyesters include, for example, polyalkylene ethers having a molecular weight in the range of 400 to 1500 Daltons (e.g., polyethylene glycol, polytetramethylene glycol, polypropylene glycol, or mixtures thereof), glyceryl monostearate, octyl epoxidized soy oleate, epoxidized soybean oil, epoxytallate, epoxidized linseed oil, polyhydroxyalkanoates, glycols (e.g., ethylene glycol, pentamethylene glycol, hexamethylene glycol, etc.), phthalates, terephthalates, trimellitates, and polyethylene glycol di-(2-ethyl hexanoate). When used, the plasticizer can be present in an amount of at least 0.1 wt%, at least 0.5 wt%, at least 1 wt%, at least 2 wt%, or at least 5 wt% and / or no more than 10 wt%, no more than 8 wt%, no more than 5 wt%, no more than 3 wt%, no more than 2 wt%, or no more than 1 wt%, based on the total weight of the waste plastic stream, or the plasticizer can be in a range of 0.1 wt% to 10 wt%, 0.5 wt% to 8 wt%, or 1 wt% to 5 wt%, based on the total weight of the waste plastic stream.

[0041] In addition, one or more methods of liquefying the waste plastic stream may also include adding at least one blending agent to the plastic stream before, during or after the liquefaction process in the liquefaction system 12. In particular, when the density difference between the plastic components of the mixed plastic stream leads to multiple liquid or semi-liquid phases, such blending agents may include, for example, emulsifiers and / or surfactants, and can be used to more fully blend the liquefied plastic into a single phase. When used, based on the total weight of the waste plastic stream, the blending agent can be at least 0.1 weight %, at least 0.5 weight %, at least 1 weight %, at least 2 weight %, or at least 5 weight % and / or no more than 10 weight %, no more than 8 weight %, no more than 5 weight %, no more than 3 weight %, no more than 2 weight %, or no more than 1 weight % The amount exists, or based on the total weight of the waste plastic stream, the blending agent can be in the range of 0.1 weight % to 10 weight %, 0.5 weight % to 8 weight %, or 1 weight % to 5 weight %.

[0042] In an embodiment or in combination with any of the embodiments mentioned herein, a portion of the pyrolysis oil stream from the pyrolysis reactor 14 can be combined with the waste plastic stream to form the liquefied plastic. Typically, in such embodiments, all or a portion of the pyrolysis oil stream can be combined with the waste plastic stream before being introduced into the liquefaction system 12, or after the waste plastic stream enters the liquefaction vessel within the liquefaction system 12.

[0043] In an embodiment or in combination with any of the embodiments mentioned herein, the liquefied (or reduced viscosity) plastic stream removed from the liquefaction system 12 may include at least 1 weight percent, at least 5 weight percent, at least 10 weight percent, at least 15 weight percent, at least 20 weight percent, at least 25 weight percent, at least 30 weight percent, at least 35 weight percent, at least 40 weight percent, at least 45 weight percent, at least 50 weight percent, at least 55 weight percent, at least 60 weight percent, at least 65 weight percent, at least 70 weight percent, at least 75 weight percent, at least 80 weight percent, at least 85 weight percent, at least 90 weight percent, at least 95 weight percent, or at least 99 weight percent and / or no more than 95 weight percent, no more than 99 weight percent, based on the total weight of the stream. %, no more than 85 wt %, no more than 80 wt %, no more than 75 wt %, no more than 70 wt %, no more than 65 wt %, no more than 60 wt %, no more than 55 wt %, no more than 50 wt %, no more than 45 wt %, no more than 40 wt %, no more than 35 wt %, no more than 30 wt %, no more than 25 wt %, no more than 20 wt %, no more than 15 wt %, no more than 10 wt %, no more than 5 wt %, no more than 2 wt %, or no more than 1 wt % of one or more polyolefins, or the amount of polyolefins may range from 1 wt % to 99 wt %, from 5 wt % to 90 wt %, or from 10 wt % to 85 wt %, based on the total weight of the stream.

[0044] In an embodiment or in combination with any embodiment mentioned herein, the liquefied plastic stream 30 exiting the plastic liquefaction system 12 may 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 rotor operating at a shear rate of 10 rad / s and a temperature of 350°C.

[0045] In an embodiment or in combination with any of the embodiments mentioned herein, the plastic liquefaction system 12 may include at least one liquefaction vessel to facilitate the liquefaction of the waste plastic. In various embodiments, the liquefaction vessel may include at least one melting tank and / or at least one extruder to facilitate the liquefaction of the plastic. Additionally, in certain embodiments, the liquefaction system 12 may also contain at least one stripping column and at least one separation vessel to facilitate the removal of halogenated compounds that may be formed in the liquefaction vessel.

[0046] In an embodiment or in combination with any of the embodiments mentioned herein, the melt tank can include one or more continuously stirred tanks. When one or more rheology modifiers (e.g., solvents, deagglomerants, plasticizers, and blending agents) are used in the liquefaction system 12, such rheology modifiers can be added to and / or mixed with the waste plastic stream in the melt tank or prior to introduction into the melt tank.

[0047] In an embodiment or in combination with any embodiment mentioned herein, a liquefaction vessel such as a melt tank and / or an extruder may receive a waste plastic feed stream 28 and heat the waste plastic via a heating mechanism in the melt tank and / or via an extrusion process in the extruder.

[0048] In an embodiment or in combination with any embodiment mentioned herein, the interior space of the liquefaction container in which the plastic is heated is maintained at a temperature of at least 200° C., at least 210° C., at least 220° C., at least 230° C., at least 240° C., at least 250° C., at least 260° C., at least 270° C., at least 280° C., at least 290° C., at least 300° C., at least 310° C., at least 320° C., at least 330° C., at least 340° C., at least 350° C., at least 360° C., at least 370° C., at least 380° C., at least 390° C., or at least 400° C. Additionally or alternatively, the interior space of the liquefaction container may be maintained at a temperature of no more than 500° C., no more than 475° C., no more than 450° C., no more than 425° C., no more than 400° C., no more than 390° C., no more than 380° C., no more than 370° C., no more than 365° C., no more than 360° C., no more than 355° C., no more than 350° C., or no more than 345° C. Generally, in one or more embodiments, the interior space of the liquefaction vessel can be maintained at a temperature ranging from 200°C to 500°C, 240°C to 425°C, 280°C to 380°C, or 320°C to 350°C.

[0049] In embodiments or in combination with any of the embodiments mentioned herein, such as Figure 1 As shown, the liquefaction vessel (such as a melting tank and / or an extruder) can be heated at least in part by a combustion system comprising a plurality of burners that burn a combustion fuel and combustion air. Figure 1As depicted, the combustion system can produce a flue gas stream that can be removed from the liquefaction system 12. The combustion fuel can include conventional fossil fuels and / or recycled content fuels, such as recycled content alkanes (eg, r-methane) and / or recycled content hydrogen derived from the chemical recovery facility 10.

[0050] In an embodiment or in combination with any of the embodiments mentioned herein, the liquefaction system 12 may optionally contain equipment for removing halogens from the waste plastic stream. When the waste plastic is heated in the liquefaction system 12, halogen-rich gases are released. By separating the released halogen-rich gases from the liquefied plastic, the halogen concentration in the liquefied plastic stream 30 can be reduced.

[0051] In an embodiment or in combination with any of the embodiments mentioned herein, dehalogenation may be facilitated by injecting a stripping gas (eg, steam) into the liquefied plastic in the melt tank.

[0052] In an embodiment or in combination with any embodiment mentioned herein, the liquefied plastic stream 30 exiting the liquefaction system 12 may 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.

[0053] In an embodiment or in combination with any embodiment mentioned herein, the halogen content of the liquefied plastic stream 30 leaving the liquefaction system 12 may not exceed 95 weight percent, not exceed 90 weight percent, not exceed 75 weight percent, not exceed 50 weight percent, not exceed 25 weight percent, not exceed 10 weight percent or not exceed 5 weight percent of the halogen content of the waste plastic stream introduced into the liquefaction system 12.

[0054] In an embodiment or in combination with any embodiment mentioned herein, the liquefied waste plastic stream 30 leaving the plastic liquefaction system 12 may have a temperature of at least 200°C, at least 225°C, at least 250°C, at least 275°C, at least 300°C, at least 310°C, at least 320°C, at least 330°C, or at least 340°C and / or less than 450°C, less than 425°C, less than 400°C, less than 375°C, or less than 350°C.

[0055] like Figure 1 As shown and described in more detail below, at least a portion of the liquefied plastic stream 30 may be introduced into a downstream pyrolysis reactor 14 at a pyrolysis facility to produce a pyrolysis effluent 32 including pyrolysis oil and pyrolysis gas.

[0056] Pyrolysis

[0057] like Figure 1As shown, the chemical recycling facility 10 may include a pyrolysis reactor 14. As used herein, the term "pyrolysis" refers to the thermal decomposition of feedstock of biomass and / or plastic materials in solid or liquid form at high temperatures in an inert (i.e., substantially free of molecular oxygen) atmosphere. A "pyrolysis facility" is a facility that includes all equipment, pipelines, and control devices required for pyrolysis of waste plastics and feedstocks derived therefrom. In certain embodiments, the pyrolysis facility may include a pyrolysis reactor 14 and an optional plastic liquefaction system 12 and / or a waste plastic source 24.

[0058] like Figure 1 As depicted, a liquefied plastic stream 30 may be introduced into a downstream pyrolysis reactor 14 at a pyrolysis facility to produce a pyrolysis effluent stream 32 comprising pyrolysis oil, pyrolysis gas, and pyrolysis residue.

[0059] In an embodiment or in combination with any of the embodiments mentioned herein, the liquefied plastic stream 30 to the pyrolysis facility can be a PO-rich stream of waste plastic. The liquefied plastic stream 30 introduced into the pyrolysis reactor 14 can be in the form of liquefied plastic (e.g., liquefied, melted, plasticized, depolymerized, or a combination thereof), plastic pellets or granules, or a slurry thereof.

[0060] Generally speaking, a pyrolysis facility may include a plastic liquefaction system 12, a pyrolysis reactor 14, and a separation system for the pyrolysis effluent ( Figure 1 The separation system may separate the pyrolysis effluent into a pyrolysis gas flow, a pyrolysis oil flow and / or a pyrolysis residue flow.

[0061] While in the pyrolysis reactor 14, at least a portion of the feed can undergo a pyrolysis reaction that produces a pyrolysis effluent comprising pyrolysis oil, pyrolysis gas, and pyrolysis residue. Typically, the pyrolysis effluent stream 32 exiting the pyrolysis reactor 14 can be in the form of pyrolysis vapor comprising pyrolysis gas and uncondensed pyrolysis oil. As used herein, "pyrolysis vapor" refers to uncondensed pyrolysis effluent comprising a majority of the pyrolysis oil and pyrolysis gas present in the pyrolysis effluent.

[0062] Pyrolysis is a process involving the chemical and thermal decomposition of the introduced feed. Although all pyrolysis processes may generally be characterized by a reaction environment that is substantially free of oxygen, pyrolysis processes may also be defined, for example, by the pyrolysis reaction temperature within the reactor, the residence time in the pyrolysis reactor 14, the type of reactor, the pressure within the pyrolysis reactor 14, and the presence or absence of a pyrolysis catalyst.

[0063] In embodiments or in combination with any of the embodiments mentioned herein, the pyrolysis reactor 14 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 14 can include a film reactor, such as a falling film reactor or an upflow film reactor.

[0064] In an embodiment or in combination with any of the embodiments mentioned herein, a lift gas and / or feed gas can be used to introduce feedstock into the pyrolysis reactor 14 and / or promote various reactions within the pyrolysis reactor 14. For example, the lift gas and / or feed gas can include, consist essentially of, or consist of nitrogen, carbon dioxide, and / or steam. The lift gas and / or feed gas can be added with the waste plastic stream prior to introduction into the pyrolysis reactor 14 and / or can be added directly to the pyrolysis reactor 14. The lift gas and / or feed gas can include steam and / or a reducing gas, such as hydrogen, carbon monoxide, and combinations thereof.

[0065] In addition, the temperature in the pyrolysis reactor 14 can be adjusted to promote the production of certain end products. In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis temperature in the pyrolysis reactor 14 can range from 325°C to 1,100°C, 350°C to 900°C, 350°C to 700°C, 350°C to 550°C, 350°C to 475°C, 425°C to 1,100°C, 425°C to 800°C, 500°C to 1,100°C, 500°C to 800°C, 600°C to 1,100°C, 600°C to 800°C, 650°C to 1,000°C, 700°C to 1,000°C, or 650°C to 800°C. Typically, in certain embodiments, the pyrolysis temperature in the pyrolysis reactor 14 can be greater than 650°C.

[0066] In an embodiment or in combination with any of the embodiments mentioned herein, the residence time of the feedstock within the pyrolysis reactor 14 may be at least 0.1 seconds, at least 0.2 seconds, at least 0.3 seconds, at least 0.5 seconds, at least 1 second, at least 1.2 seconds, at least 1.3 seconds, at least 2 seconds, at least 3 seconds, or at least 4 seconds. Alternatively, the residence time of the feedstock within the pyrolysis reactor 14 may be at least 1 minute, at least 2 minutes, at least 3 minutes, at least 4 minutes, at least 5 minutes, at least 6 minutes, at least 7 minutes, at least 8 minutes, at least 9 minutes, at least 10 minutes, at least 20 minutes, at least 30 minutes, at least 45 minutes, at least 60 minutes, at least 75 minutes, or at least 90 minutes. Additionally or alternatively, the residence time of the feedstock within the pyrolysis reactor 14 may be less than 6 hours, less than 5 hours, less than 4 hours, less than 3 hours, less than 2 hours, less than 1 hour, or less than 0.5 hours. In addition, the residence time of the feedstock in the pyrolysis reactor 14 may be less than 100 seconds, less than 90 seconds, less than 80 seconds, less than 70 seconds, less than 60 seconds, less than 50 seconds, less than 40 seconds, less than 30 seconds, less than 20 seconds, less than 10 seconds, less than 9 seconds, less than 8 seconds, less than 7 seconds, less than 6 seconds, less than 5 seconds, less than 4 seconds, less than 3 seconds, less than 2 seconds, or less than 1 second. More specifically, the residence time of the feedstock in the pyrolysis reactor 14 may 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.

[0067] In an embodiment or in combination with any of the embodiments mentioned herein, the pressure within the pyrolysis reactor 14 can be maintained at atmospheric pressure or in 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. Unless otherwise specified, as used herein, the term "bar" refers to gauge pressure.

[0068] In an embodiment or in combination with any of the embodiments mentioned herein, a pyrolysis catalyst can be introduced into the liquefied plastic stream 30 prior to introduction into the pyrolysis reactor 14 and / or directly into the pyrolysis reactor 14. The catalyst can be homogeneous or heterogeneous and can include, for example, certain types of zeolites and other mesostructured catalysts.

[0069] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis reaction may not be catalyzed (e.g., carried out in the absence of a pyrolysis catalyst), but a non-catalytic, heat-retaining inert additive (such as sand) may be included in the reactor to facilitate heat transfer. Such catalyst-free pyrolysis methods may be referred to as "thermal pyrolysis".

[0070] In embodiments or in combination with any of the embodiments mentioned herein, such as Figure 1 As shown, the pyrolysis reactor 14 can be heated at least in part by a combustion system including a plurality of burners that burn a combustion fuel and combustion air. Figure 1 As depicted, the combustion system can produce a flue gas stream that can be removed from the pyrolysis reactor 14. The combustion fuel can include conventional fossil fuels and / or recycled content fuels, such as recycled content alkanes (e.g., r-methane) and / or recycled content hydrogen derived from the chemical recovery facility 10.

[0071] After leaving the pyrolysis reactor 14, the pyrolysis effluent can be separated into a pyrolysis oil stream and a pyrolysis gas stream in a separation system. Figure 1 32, but the separation system may include various types of equipment, including but not limited to filtration systems, multi-stage separators, condensation zones, distillation columns, and / or quench columns. While in the separation system, the pyrolysis effluent (such as pyrolysis vapor) may be cooled to condense the pyrolysis oil fraction originally present in the pyrolysis effluent stream 32.

[0072] In an embodiment or in combination with any of the embodiments mentioned herein, the pyrolysis effluent or pyrolysis vapors from the pyrolysis reactor 14 may contain at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, or at least 75 wt% pyrolysis oil, based on the total weight of the pyrolysis effluent or pyrolysis vapors. Additionally or alternatively, the pyrolysis effluent or pyrolysis vapors may contain no more than 99 wt%, no more than 95 wt%, no more than 90 wt%, no more than 85 wt%, no more than 80 wt%, no more than 75 wt%, no more than 70 wt%, no more than 65 wt%, no more than 60 wt%, no more than 55 wt%, no more than 50 wt%, no more than 45 wt%, no more than 40 wt%, no more than 35 wt%, no more than 30 wt%, or no more than 25 wt% of 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 when leaving the heated reactor; however, these vapors may subsequently be condensed into the resulting pyrolysis oil. The pyrolysis effluent or pyrolysis vapors may contain pyrolysis oil in a range of 20 wt % to 99 wt %, 25 wt % to 80 wt %, 30 wt % to 85 wt %, 30 wt % to 80 wt %, 30 wt % to 75 wt %, 30 wt % to 70 wt %, or 30 wt % to 65 wt %, based on the total weight of the pyrolysis effluent or pyrolysis vapors.

[0073] In an embodiment or in combination with any of the embodiments mentioned herein, the pyrolysis effluent or pyrolysis vapor from the pyrolysis reactor 14 may contain at least 1 wt%, at least 5 wt%, at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, or at least 80 wt% pyrolysis gas, based on the total weight of the pyrolysis effluent or pyrolysis vapor. Additionally or alternatively, based on the total weight of the pyrolysis effluent or pyrolysis vapor, the pyrolysis effluent or pyrolysis vapor may comprise no more than 99 wt %, no more than 95 wt %, no more than 90 wt %, no more than 85 wt %, no more than 80 wt %, no more than 75 wt %, no more than 70 wt %, no more than 65 wt %, no more than 60 wt %, no more than 55 wt %, no more than 50 wt %, or no more than 45 wt % of the pyrolysis gas. Based on the total weight of the stream, the pyrolysis effluent may comprise 1 wt % to 90 wt %, 10 wt % to 85 wt %, 15 wt % to 85 wt %, 20 wt % to 80 wt %, 25 wt % to 80 wt %, 30 wt % to 75 wt %, or 35 wt % to 75 wt % of the pyrolysis gas.

[0074] In an embodiment or in combination with any of the embodiments mentioned herein, the pyrolysis effluent or pyrolysis vapor from the pyrolysis reactor 14 may contain at least 0.5 wt%, at least 1 wt%, at least 2 wt%, at least 3 wt%, at least 4 wt%, at least 5 wt%, at least 6 wt%, at least 7 wt%, at least 8 wt%, at least 9 wt%, or at least 10 wt% of pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapor. Additionally or alternatively, the pyrolysis effluent may contain no more than 60 wt%, no more than 50 wt%, no more than 40 wt%, no more than 30 wt%, no more than 25 wt%, no more than 20 wt%, no more than 15 wt%, no more than 10 wt%, no more than 9 wt%, no more than 8 wt%, no more than 7 wt%, no more than 6 wt%, or no more than 5 wt% of pyrolysis residue, based on the total weight of the pyrolysis effluent or pyrolysis vapor. Based on the total weight of the pyrolysis effluent or pyrolysis vapor, the pyrolysis effluent may contain 0.1 wt % to 25 wt %, 1 wt % to 15 wt %, 1 wt % to 8 wt %, or 1 wt % to 5 wt % of the pyrolysis residue. Such pyrolysis residue may be removed from the pyrolysis reactor 14 (where the pyrolysis residue may be formed) and / or separated from the pyrolysis effluent in a downstream separator (such as a condenser).

[0075] The resulting pyrolysis oil stream and pyrolysis gas stream can be used directly in various downstream applications based on their formulation. Various characteristics and properties of pyrolysis oil, pyrolysis gas and pyrolysis residue are described below. It should be noted that although all of the following characteristics and properties can be listed individually, it is contemplated that each of the following characteristics and / or properties of pyrolysis gas, pyrolysis oil and / or pyrolysis residue are not mutually exclusive and can be combined and present in any combination.

[0076] In embodiments or in combination with any embodiment mentioned herein, pyrolysis oil may mainly comprise hydrocarbons (e.g., C4 to C30 hydrocarbons) having 4 to 30 carbon atoms per molecule. As used herein, the term "Cx" or "Cx hydrocarbons" refers to hydrocarbon compounds containing a total of "x" carbons per molecule, and encompasses all olefins, paraffins, aromatic hydrocarbons, heterocycles, and isomers with this number of carbon atoms. For example, n-butane, isobutane, and tert-butane, as well as each of butene and butadiene molecules will fall under the general description "C4". Based on the gross weight of the pyrolysis oil stream, the pyrolysis oil may have a C4-C30 hydrocarbon content of at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt%.

[0077] In an embodiment or in combination with any of the embodiments mentioned herein, the pyrolysis oil may comprise primarily C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons. For example, based on the total weight of the pyrolysis oil stream, the pyrolysis oil may comprise at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90 wt%, or at least 95 wt% of C5 to C25 hydrocarbons, C5 to C22 hydrocarbons, or C5 to C20 hydrocarbons.

[0078] In an embodiment or in combination with any of the embodiments mentioned herein, the pyrolysis oil may have a medium boiling point in the range of 75° C. to 250° C., 90° C. to 225° C., or 115° C. to 190° C. as measured according to ASTM D-5399. As used herein, "medium boiling point" refers to the median boiling point temperature of the pyrolysis oil, wherein 50% by volume of the pyrolysis oil boils above the medium boiling point and 50% by volume of the pyrolysis oil boils below the medium boiling point.

[0079] In an embodiment or in combination with any embodiment mentioned herein, the boiling point range of the pyrolysis oil can be such that at least 90% of the pyrolysis oil boils at a temperature of 250°C, 280°C, 290°C, 300°C, or 310°C as measured according to ASTM D-5399.

[0080] As described above, pyrolysis conditions, such as temperature, may be controlled in order to maximize the yield of certain hydrocarbons and chemical compounds in the resulting pyrolysis gas and pyrolysis oil.

[0081] Turning to the pyrolysis gas, the pyrolysis gas can have a methane content in a range of 1 wt % to 50 wt %, 5 wt % to 50 wt %, or 15 wt % to 45 wt %, based on the total weight of the pyrolysis gas stream.

[0082] In an embodiment or in combination with any embodiment mentioned herein, the pyrolysis gas may have a C3 and / or C4 hydrocarbon content (including all hydrocarbons having 3 or 4 carbon atoms per molecule) in the range of 10 wt% to 90 wt%, 25 wt% to 90 wt%, or 25 wt% to 80 wt%, based on the total weight of the pyrolysis gas stream.

[0083] In an embodiment or in combination with any of the embodiments mentioned herein, the pyrolysis gas can have a combined ethylene and propylene content of at least 25 wt%, at least 40 wt%, at least 50 wt%, at least 60 wt%, at least 70 wt%, or at least 75 wt%, based on the total weight of the pyrolysis gas stream.

[0084] Turning to the pyrolysis residue, in an embodiment or in combination with any of the embodiments mentioned herein, the pyrolysis residue comprises at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, or at least 85 wt% C20+ hydrocarbons, based on the total weight of the pyrolysis residue. As used herein, "C20+ hydrocarbons" refers to hydrocarbon compounds containing a total of at least 20 carbons per molecule, and encompasses all olefins, paraffins, and isomers having that number of carbon atoms.

[0085] like Figure 1 As shown, at least a portion of the pyrolysis effluent (such as a pyrolysis gas stream, a pyrolysis oil vapor, and / or a pyrolysis residual stream) can be conveyed to one or more other chemical processing facilities, including, for example, a cracking facility. In an embodiment or in combination with any embodiment mentioned herein, at least a portion of the pyrolysis effluent (such as a pyrolysis oil stream and / or a pyrolysis gas stream) can be conveyed to a cracking furnace 16 of a cracking facility.

[0086] Cracking

[0087] In an embodiment or in combination with any embodiment mentioned herein, at least a portion of one or more streams (including pyrolysis oil stream and / or pyrolysis gas stream) from a pyrolysis facility may be introduced into a cracking facility. As used herein, the term "cracking" refers to the decomposition of complex organic molecules into simpler molecules by the breaking of carbon-carbon bonds. "Cracking facility" refers to a facility comprising all equipment, pipelines and control devices required for cracking raw materials derived from waste plastics. The cracking facility may include one or more cracking furnaces, a quenching system 18 for cooling the cracked products 34, a compression system 20, and a downstream separation zone 22 including equipment for processing the effluent of the cracking furnace 16. As used herein, the terms "cracker" and "cracking" are used interchangeably.

[0088] In general, a cracker facility may include a cracking furnace 16, a quench system 18, a compression system, and a separation zone located downstream of the cracking furnace 16 for separating the furnace effluent into various end products, such as a recovery component hydrocarbon (e.g., r-hydrocarbon) stream. In an embodiment or in combination with any of the embodiments mentioned herein, at least a portion of the pyrolysis oil stream and / or the pyrolysis gas stream may be sent to the cracking facility. The pyrolysis oil stream may be introduced into the inlet of the cracking furnace 16, and the pyrolysis gas stream may be introduced into a location upstream or downstream of the furnace. As Figure 1 As shown, the effluent from the cracking furnace 16 may be separated into various recovered component products in a downstream separator 22. When used, the pyrolysis oil stream and / or the pyrolysis gas stream may optionally be combined with the cracker feed stream to form the feed stream to the cracking facility.

[0089] In an embodiment or in combination with any embodiment mentioned herein, the cracker feed stream may include a hydrocarbon feed other than the pyrolysis gas and pyrolysis oil streams, in an amount of 5 wt% to 95 wt%, 10 wt% to 90 wt%, or 15 wt% to 85 wt%, based on the total weight of the cracker feed.

[0090] In an embodiment or in combination with any of the embodiments mentioned herein, the cracker facility may include a single cracking furnace, or it may 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 operating in parallel. Any one or each furnace may be a gas cracking furnace, or a liquid cracking furnace, or a split furnace.

[0091] The cracker feed stream may be passed through a cracking furnace along with a pyrolysis oil stream and / or pyrolysis gas, wherein the hydrocarbon components in the stream 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 may be in the range of 0.15 to 2 seconds, 0.20 to 1.75 seconds, or 0.25 to 1.5 seconds.

[0092] The temperature of the cracked olefin-containing effluent withdrawn from the furnace outlet may be in the range of 730°C to 900°C, 750°C to 875°C, or 750°C to 850°C.

[0093] In an embodiment or in combination with any of the embodiments mentioned herein, the cracking furnace 16 can be heated at least in part by a combustion system that includes a plurality of burners that combust a combustion fuel and combustion air. Additionally, the combustion system can produce a flue gas stream that can be removed from the cracking furnace 16. The combustion fuel can include conventional fossil fuels and / or recycled component fuels, such as recycled component alkanes (e.g., r-methane) and / or recycled component hydrogen derived from the chemical recovery facility 10.

[0094] In an embodiment or in combination with any of the embodiments mentioned herein, based on the total weight of the olefin-containing effluent stream, from a separator 22 (e.g. Figure 1 The recovered olefin-containing stream removed from the effluent stream (shown in the figure) may contain at least 10 wt%, at least 15 wt%, at least 20 wt%, at least 25 wt%, at least 30 wt%, at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, or at least 90 wt% of recovered C2 to C4 olefins. The recovered olefin-containing stream may contain primarily recovered ethylene, primarily recovered propylene, or primarily recovered ethylene and recovered propylene, based on the total weight of the olefin-containing effluent stream.

[0095] In an embodiment or in combination with any of the embodiments mentioned herein, when introduced into a cracker facility, the pyrolysis gas stream may be introduced into the inlet of the cracking furnace 16, or all or a portion of the pyrolysis gas stream may be introduced downstream of the furnace outlet, upstream of or within a separation zone of the cracker facility. When introduced into or upstream of the separation zone, the pyrolysis gas may be introduced upstream of the last stage of compression in the compressor 20, or before the inlet of at least one fractionation column in the fractionation section of the separator 22.

[0096] Upon leaving the cracking furnace outlet, the olefin-containing effluent stream 34 may be rapidly cooled (e.g., quenched) in the quench system 18 to prevent the production of large amounts of undesirable byproducts and minimize fouling in downstream equipment. The quench system 18 may produce a quenched olefin-containing effluent stream 36 and a quench waste fluid stream that may contain water, residual quench oil, and / or residual steam.

[0097] Finally, if Figure 1As shown, the cracking facility may include one or more utility boilers 40 or gas turbines to generate steam and / or additional mechanical work for the facility. As with the cracking furnace 16, the utility boilers 40 or gas turbines may be heated at least in part by a combustion system including a plurality of burners that combust a combustion fuel and combustion air. As discussed below, the utility boilers and gas turbines may generate additional flue gas streams that may be used for heat recovery purposes.

[0098] In an embodiment or in combination with any of the embodiments mentioned herein, at least a portion of one or more of the above streams may be introduced into Figure 1 In one or more of the facilities shown, while in other embodiments, all or a portion of the stream removed from the separation zone of the cracking facility may be routed for further separation and / or storage, transportation, sale and / or use.

[0099] Thermal integration with waste streams

[0100] As described above, we have found that the carbon footprint of a chemical recovery facility 10 can be reduced by recovering waste heat from various waste streams back into the chemical recovery process. Figure 1 , the chemical recovery facility 10 may contain at least one heat transfer medium loop 38, the heat transfer medium loop containing at least one fluid energy source, the fluid energy source can transfer at least a portion of the heat energy from the fluid energy source to the following items: (i) the waste plastic undergoing liquefaction in step (a), (ii) a combustion fuel stream used to generate heat for plastic liquefaction, waste plastic pyrolysis, cracking furnace 16, gas turbine and / or utility boiler 40, and / or (iii) a combustion air stream used to generate heat for plastic liquefaction, waste plastic pyrolysis, cracking furnace 16, gas turbine and / or utility boiler 40. Figure 1 As shown, the fluid energy source may include a variety of different waste streams that are typically undergoing or being emptied, such as flue gas from the liquefaction system 12, flue gas from the pyrolysis reactor 14, flue gas from the cracking furnace 16, flue gas from the utility boiler 40 used to generate steam from the quench system 18, oil and / or water waste streams, a waste steam stream from the quench system 18, a residual waste steam stream from the compressor 20, a waste steam stream from the cracking separator 22 and / or a flue gas stream from a gas turbine.

[0101] As described above, a fluid energy source for heat recovery purposes may include any waste stream in a chemical facility that is or normally undergoes drainage. Figure 1As shown, these waste streams may include: (i) flue gas from the plastic liquefaction system 12, (ii) flue gas from the pyrolysis reactor 14, (iii) flue gas from the cracking furnace 16, (iv) flue gas from the utility boiler 40 for generating steam, (v) oil and / or water waste streams from the quench system 18, (vi) waste steam stream from the quench system 18, (vii) waste steam stream from the compressor 20, (viii) waste steam stream from the cracking separator 22, and / or (ix) flue gas stream from the gas turbine.

[0102] In an embodiment or in combination with any of the embodiments mentioned herein, each of the above waste streams may have a temperature of at least 80° C., at least 90° C., at least 100° C., or at least 110° C. Additionally, or alternatively, the above waste streams may have a temperature of no more than 260° C., no more than 250° C., no more than 240° C., no more than 230° C., no more than 220° C., no more than 210° C., no more than 200° C., no more than 190° C., no more than 180° C., no more than 170° C., no more than 160° C., or no more than 150° C. In certain embodiments, the above waste streams may have a temperature in the range of 80° C. to 260° C., 90° C. to 260° C., 100° C. to 260° C., or 110° C. to 260° C.

[0103] In an embodiment or in combination with any of the embodiments mentioned herein, each of the above waste streams can have an enthalpy of at least 800 BTU / lb, at least 850 BTU / lb, at least 900 BTU / lb, at least 950 BTU / lb, at least 1,000 BTU / lb, at least 1,050 BTU / lb, at least 1,100 BTU / lb, or at least 1,050 BTU / lb. Additionally, or alternatively, each of the above waste streams can have an enthalpy of no more than 1,600 BTU / lb, no more than 1,550 BTU / lb, no more than 1,500 BTU / lb, no more than 1,450 BTU / lb, no more than 1,400 BTU / lb, no more than 1,350 BTU / lb, or no more than 1,300 BTU / lb. In certain embodiments, each of the above waste streams may have an enthalpy in the range of 800 to 1,600 BTU / lb, 900 to 1,550 BTU / lb, or 1,000 to 1,400 BTU / lb.

[0104] In an embodiment or in combination with any embodiment mentioned herein, each of the above waste streams may have a pressure of no more than 400 psi, no more than 350 psi, no more than 300 psi, no more than 250 psi, no more than 200 psi, no more than 150 psi, no more than 100 psi, no more than 75 psi, no more than 50 psi, no more than 25 psi or no more than 10 psi.

[0105] In an embodiment or in combination with any embodiment mentioned herein, the waste stream may comprise steam at a pressure of no more than 400 psi, no more than 350 psi, no more than 300 psi, no more than 250 psi, no more than 200 psi, no more than 150 psi, no more than 100 psi, no more than 75 psi, no more than 50 psi, no more than 25 psi, or no more than 10 psi.

[0106] like Figure 1 As shown, one or more of the above waste streams may be recovered and utilized in a heat transfer medium ("HTM") loop 38. Figure 1 As depicted, any one or a combination of the above waste streams may be recovered and provide thermal energy to: (i) waste plastics undergoing plastic liquefaction, (ii) a combustion fuel stream used to generate heat for plastic liquefaction, waste plastic pyrolysis, a cracking furnace 16, a gas turbine, and / or a utility boiler 40, and / or (iii) a combustion air stream used to generate heat for plastic liquefaction, waste plastic pyrolysis, a cracking furnace 16, a gas turbine, and / or a utility boiler 40. Heat exchange between the above waste streams and the waste plastic stream, the combustion fuel stream, and / or the combustion air stream may be performed via indirect heat exchange in a heat exchanger 42. The heat exchanger 42 may include any conventional cross-flow heat exchanger known in the art, such as a transfer line exchanger. In certain embodiments, the heat exchanger 42 may include a brazed aluminum heat exchanger including a plurality of cooling and heating passages (e.g., cores) disposed therein to facilitate indirect heat exchange between one or more process streams and at least one heat transfer medium stream. Although in Figure 1 4. Heat exchanger 42 is generally shown as including a single core or "shell", but it should be understood that heat exchanger 42 may include two or more separate cores or shells.

[0107] like Figure 1 As shown, the terms "HTM outgoing" and "HTM incoming" are used for the sake of brevity and to depict where the indicated waste streams may be recovered and / or introduced downstream in the chemical recovery facility 10. Although Figure 1 It is not depicted, but the relevant waste streams may undergo additional processing and / or separation after the "HTM Outgoing" notation and before the "HTM Incoming" notation. It should be understood that unless otherwise indicated, Figure 1 In the example, any waste stream removed at the point labeled "HTM Out" can be introduced at any point labeled "HTM In".

[0108] In an embodiment or in combination with any of the embodiments mentioned herein, the waste stream in the heat transfer medium loop 38 may include flue gas from the plastic liquefaction system 12, flue gas from the pyrolysis reactor 14, and / or flue gas from the cracking furnace 16. In such embodiments, at least a portion of the waste stream can be used to heat: (i) waste plastic undergoing plastic liquefaction, (ii) a combustion fuel stream for generating heat for plastic liquefaction, waste plastic pyrolysis, and / or cracking furnace 16, and / or (iii) a combustion air stream for generating heat for plastic liquefaction, waste plastic pyrolysis, and / or cracking furnace 16.

[0109] After indirect heat exchange with a specified waste stream, the temperature of the treated stream (i.e., the waste plastic stream, the combustion fuel stream, and / or the combustion air stream before liquefaction) may increase. In an embodiment or in combination with any embodiment mentioned herein, after indirect heat exchange with a specified waste stream, the temperature of the treated stream may increase by at least 10°C, at least 25°C, at least 50°C, at least 75°C, at least 100°C, at least 125°C, at least 150°C, at least 175°C, or at least 200°C and / or no more than 300°C, no more than 250°C, no more than 200°C, or no more than 150°C.

[0110] After indirect heat exchange with a designated stream (i.e., a waste plastic stream prior to liquefaction, a combustion fuel stream, and / or a combustion air stream), the cooled waste stream may have a temperature of no more than 100°C, no more than 95°C, no more than 90°C, no more than 85°C, or no more than 80°C.

[0111] After supplying thermal energy, the cooled waste stream can be vented from the chemical recovery facility 10. Optionally, in many cases, the cooled waste stream may contain a certain amount of carbon dioxide and / or other components that are not desirable for downstream separation and / or other chemical recovery methods. Since the waste stream is cooled in the previous preheating step, the cooled waste stream can be easily processed in the CO2 purification system 26 without any further cooling to effectively recover at least a portion of the CO2 in the cooled waste stream.

[0112] like Figure 1 As shown, we have discovered that the carbon footprint of the chemical recovery facility 10 can be further reduced by recovering (e.g., via capture and / or storage) CO2 from at least a portion of the cooled waste stream. Figure 1 As shown, at least a portion of the cooled waste stream may be introduced into the CO2 purification system 26 to produce a lean CO2 stream and a captured CO2 stream. In certain embodiments, the CO2 purification system 26 may include a CO2 absorber including at least one absorber and at least one stripper / regenerator.

[0113] While in the CO2 purification system 26, at least a portion of the cooled waste stream can be introduced into one or more absorbers, where the stream contacts an absorber solvent (i.e., a lean absorber solvent) that is simultaneously introduced into the one or more absorbers. Upon contact, at least a portion of the carbon dioxide and / or other impurities in the cooled waste stream can be absorbed and removed in the resulting rich absorber solvent stream.

[0114] Typically, the absorber solvent may include an organic solvent. In an embodiment or in combination with any embodiment mentioned herein, the absorber solvent may include an absorption component selected from the group consisting of: amines, methanol, sodium hydroxide, sodium carbonate / bicarbonate, potassium hydroxide, potassium carbonate / bicarbonate, Glycol ethers and combinations thereof. The absorption component may include an amine selected from the group consisting of diethanolamine (DEA), monoethanolamine (MEA), methyldiethanolamine (MDEA), diisopropanolamine (DIPA), diglycolamine (DGA), piperazine, modifications, derivatives, and combinations thereof.

[0115] The resulting CO2-lean stream exits the absorber overhead and is substantially depleted of carbon dioxide relative to the cooled waste stream fed to the absorber.

[0116] The absorbed carbon dioxide in the rich absorber solvent stream can be removed from the absorber solvent in the stripper / regenerator. In the stripper / regenerator, the carbon dioxide can be stripped from the rich absorber solvent by contacting the solvent with water / steam. The recovered carbon dioxide gas can be removed as a captured CO2 stream. After CO2 removal, the resulting lean absorber solvent stream can be recycled back to the absorber.

[0117] like Figure 1 As shown, at least a portion of the CO2 lean stream may be removed from the facility.

[0118] In embodiments or in combination with any of the embodiments mentioned herein, the captured CO2 stream is enriched in CO2 content relative to the cooled waste stream. For example, the recovered CO2 stream may comprise 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%, at least 96%, at least 97%, at least 98%, or at least 99% of the CO2 originally present in the cooled waste stream.

[0119] The captured CO2 stream can be removed from the system and used to produce various end products (e.g., as a raw material for the synthesis of various chemicals and foods, such as carbonation) and / or in Figure 1 Further processing takes place in downstream facilities not depicted.

[0120] definition

[0121] It should be understood that the following is not intended to be an exhaustive list of defined terms. Other definitions may be provided in the foregoing description, such as, for example, where context accompanies the use of a defined term.

[0122] As used herein, the terms "a," "an," and "the" mean one or more.

[0123] 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 may be used alone, or any combination of two or more of the listed items may be used. For example, if a composition is described as containing components A, B, and / or C, the composition may contain only A; only B; only C; a combination of A and B; a combination of A and C, a combination of B and C; or a combination of A, B, and C.

[0124] 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.

[0125] As used herein, "aqueous" means that the fluid contains at least 5% by weight molecular water.

[0126] As used herein, the term "bottom" refers to the physical location of a structure within an enclosed structure that is below other known structures. For example, a "bottom" stream is a stream taken from a container at a location that is lower in height than other streams taken from the container, such as a "top" stream.

[0127] As used herein, the term "chemical recycling" refers to a waste plastic recycling process that includes the steps of chemically converting waste plastic polymers into lower molecular weight polymers, oligomers, monomers and / or non-polymer molecules (e.g., hydrogen, carbon monoxide, methane, ethane, propane, ethylene and propylene) that are useful in themselves and / or can be used as feedstock for another (other) chemical production process.

[0128] As used herein, the term "chemical recycling facility" refers to a facility that produces a recycled content product through the chemical recycling of waste plastics.

[0129] As used herein, the term "co-located" refers to the property of at least two objects being located in the same physical location and / or within one mile of each other.

[0130] As used herein, the terms "comprising," "comprises," and "comprise" are open transition words that are used to transition from an object recited before the term to one or more elements recited after the term, wherein the one or more elements listed after the transition word are not necessarily the only elements that make up the subject matter.

[0131] As used herein, the term "cracking" refers to the decomposition of complex organic molecules into simpler molecules by the breaking of carbon-carbon bonds.

[0132] As used herein, the term "depleted" means that the concentration of a particular component (on a dry weight basis) is less than the concentration of that component in a reference material or stream.

[0133] As used herein, the term "directly sourced" means having at least one physical component derived from waste plastics.

[0134] As used herein, the term "enriched" refers to the concentration of a particular component (on a dry weight basis) being greater than the concentration of that component in a reference material or stream.

[0135] As used herein, the term "exhaustion" or "exhausting" refers to a method of disposing of a specified stream by removing the stream from a facility. Exemplary exhaust methods may include exhausting gas.

[0136] As used herein, the term "fluid" may encompass liquids, gases, supercritical fluids, or combinations thereof.

[0137] As used herein, the term "halide" refers to a composition comprising a halogen atom with a negative charge (ie, a halide ion).

[0138] As used herein, the term "halogen" or "halogens" refers to an organic or inorganic compound, ion or elemental species containing at least one halogen atom.

[0139] As used herein, the terms "having, has, and have" have the same open-ended meaning as "comprising, comprises, and comprise" provided above.

[0140] As used herein, a "heat transfer medium loop" or "HTM loop" refers to a system including one or more heat exchangers through which a common HTM is circulated to a common HTM supply or part of a larger system for the purpose of transferring heat and / or energy into and / or out of a chemical recovery process.

[0141] As used herein, the terms "including, include, and included" have the same open-ended meaning as "comprising, comprise, and comprise" provided above.

[0142] As used herein, the term "indirectly sourced" refers to having an assigned recycled content that is i) attributable to waste plastics but ii) is not based on having a physical component derived from waste plastics.

[0143] As used herein, the term "separate" refers to the property of one or more objects being self-contained or by themselves and separate from other materials, whether in motion or at rest.

[0144] 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 polyvinyl chloride (PVC).

[0145] As used herein, "non-aqueous" refers to fluids containing less than 5% by weight of molecular water.

[0146] As used herein, the term "overhead" refers to a physical location within a closed structure that is above the maximum height of a mass of particulate plastic solids. For example, an "overhead" stream is a stream taken from a container at a location that is higher in height than other streams taken from the container, such as a "bottom" stream.

[0147] As used herein, the term "partially processed waste plastics" means waste plastics that have been subjected to at least one automated or mechanized sorting, washing or shredding step or process. Partially processed waste plastics may originate from, for example, a municipal recycling facility (MRF) or a regeneration unit. When partially processed waste plastics are provided to a chemical recycling facility, one or more pre-processing steps may be skipped.

[0148] As used herein, the term "physical recycling" (also referred to as "mechanical recycling") refers to a waste plastic recycling process that includes the steps of melting the waste plastic and forming the molten plastic into new intermediate products (e.g., pellets or sheets) and / or new end products (e.g., bottles). Typically, physical recycling does not substantially change the chemical structure of the plastic, although some degradation may occur.

[0149] As used herein, the term "plastic" may include any organic synthetic polymer that is solid at 25°C and 1 atmosphere of pressure.

[0150] As used herein, the term "primarily" means greater than 50% by weight. For example, a stream, composition, feedstock, or product that is primarily propane is a stream, composition, feedstock, or product that contains greater than 50% by weight propane.

[0151] As used herein, the term "pretreatment" refers to preparing waste plastic for chemical recycling using one or more of the following steps: (i) comminution, (ii) pelletization, (iii) washing, (iv) drying and / or (v) separation.

[0152] As used herein, the term "pyrolysis" refers to the thermal decomposition of feedstock of biomass and / or plastic materials in solid or liquid form at elevated temperatures in an inert (ie, substantially free of molecular oxygen) atmosphere.

[0153] As used herein, the term "pyrolytic coke" refers to a carbonaceous composition obtained from pyrolysis that is solid at 200°C and 1 standard atmosphere.

[0154] As used herein, the term "pyrolysis gas" and "pygas" refers to a composition obtained from pyrolysis that is gaseous at 25°C and 1 standard atmosphere pressure.

[0155] As used herein, the term "pyrolysis heavy wax" refers to C20+ hydrocarbons obtained from pyrolysis, which are not pyrolysis coke, pyrolysis gas or pyrolysis oil.

[0156] As used herein, the term "pyrolysis oil (pyoil)" refers to a composition obtained by pyrolysis that is liquid at 25°C and 1 standard atmosphere.

[0157] As used herein, the term "pyrolysis residue" refers to a composition obtained from pyrolysis that is not pyrolysis gas or pyrolysis oil and primarily comprises pyrolysis coke and pyrolysis heavy wax.

[0158] As used herein, the terms "recycled content" and "r-content" refer to compositions that are or include compositions that are directly and / or indirectly derived from waste plastics.

[0159] As used herein, the term "r-pyrolysis gas" or "r-pyrolysis gas" refers to or contains pyrolysis gas that is directly and / or indirectly derived from waste plastics.

[0160] As used herein, the term "r-pyrolysis oil" or "r-pyrolysis oil" refers to or comprises pyrolysis oil that is directly and / or indirectly derived from waste plastics.

[0161] As used herein, the term "residual" refers to the remaining amount or quantity of an identified product or component remaining from an original source containing the identified product or component. For example, "residual pyrolysis oil" may refer to the remaining pyrolysis oil in the initial pyrolysis effluent after most of the pyrolysis oil has previously been removed from the initial pyrolysis effluent.

[0162] As used herein, the terms "waste plastic" and "plastic waste" refer to used, discarded and / or discarded plastic materials. Waste plastics fed to a chemical recycling facility may be unprocessed or partially processed.

[0163] As used herein, the term "unprocessed waste plastic" means waste plastic that has not yet been subjected to any automated or mechanized sorting, washing or shredding. Examples of unprocessed waste plastic include waste plastic collected from household curbside plastic recycling bins or shared community plastic recycling containers.

[0164] As used herein, "downstream" means a target unit operation, vessel, or equipment that:

[0165] a. in fluid communication or pipe communication with an outlet stream (liquid or gaseous) from a radiant section of a cracking furnace, optionally via one or more intermediate unit operations, vessels or apparatus, or

[0166] b. Fluid or pipeline connection with the outlet stream (liquid or gas) from the radiant section of the cracking 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 limit of the cracker facility (including the furnace and all associated downstream separation equipment).

[0167] The claims are not limited to the disclosed embodiments

[0168] When indicating a numerical sequence, it should be understood that each number is modified to be the same as the first or last number in the numerical sequence or sentence, for example, 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% by weight..." has the same meaning as "at least 10% by weight, or at least 20% by weight, or at least 30% by weight, or at least 40% by weight, or at least 50% by weight, or at least 75% by weight", etc.; and "not more than 90% by weight, 85, 70, 60% by weight..." has the same meaning as "not more than 90% by weight, or not more than 85% by weight, or not more than 70% by weight...", etc.; and "at least 1% by weight, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, 21% by weight, 22% by weight, 23% by weight, 24% by weight, 25% by weight, 26% by weight, 27% by weight, 28% by weight, 29% by weight, 30% by weight, 31% by weight, 32% by weight, 33% by weight, 34% by weight, 36% by weight, 37% by weight, 38% by weight, 39% by weight, 40% by weight, 41% by weight, 42% by weight, 43% by weight, 44% by weight, 45 “At least 1% by weight, or at least 2% by weight, or at least 3% by weight…” has the same meaning as “at least 1% by weight, or at least 2% by weight, or at least 3% by weight…” etc.; and “at least 5, 10, 15, 20 and / or not more than 99, 95, 90% by weight” has the same meaning as “at least 5% by weight, or at least 10% by weight, or at least 15% by weight, or at least 20% by weight and / or not more than 99% by weight, or not more than 95% by weight, or not more than 90% by weight…” etc.

[0169] The preferred forms of the present invention described above are intended to be used as illustrations only and should not be used in a limiting sense to interpret the scope of the present invention. Those skilled in the art may easily make modifications to the above exemplary embodiments without departing from the spirit of the present invention.

[0170] The inventors hereby declare that they intend to determine and assess the reasonable and fair scope of the present invention under the doctrine of equivalents as it relates to any device that does not materially depart from the literal scope of the present invention as set forth in the following claims.

Claims

1. A chemical recovery method comprising: (a) liquefying at least a portion of the waste plastic in a liquefaction system to form liquefied waste plastic; (b) pyrolyzing at least a portion of the liquefied waste plastic to produce a pyrolysis effluent; as well as (c) preheating at least a portion of an initial stream with a fluid energy source, wherein the initial stream comprises one or more of the following: (i) said waste plastics subjected to said liquefaction of step (a), (ii) a combustion fuel stream for generating heat for said liquefaction of step (a) and / or said pyrolysis of step (b), or (iii) a combustion air stream for generating heat for said liquefaction of step (a) and / or said pyrolysis of step (b), Wherein the fluid energy source has a temperature in the range of 80°C to 260°C.

2. The chemical recovery method according to claim 1, wherein the fluid energy source is emptied after the preheating in step (c).

3. The chemical recovery method of claim 1 or 2, wherein the fluid energy source has an enthalpy of at least 800 BTU / lb, at least 850 BTU / lb, at least 900 BTU / lb, at least 950 BTU / lb, at least 1,000 BTU / lb, at least 1,050 BTU / lb, at least 1,100 BTU / lb, or at least 1,050 BTU / lb.

4. The chemical recovery method of any one of claims 1-3, wherein the fluid energy source has an enthalpy of no more than 1,600 BTU / lb, no more than 1,550 BTU / lb, no more than 1,500 BTU / lb, no more than 1,450 BTU / lb, no more than 1,400 BTU / lb, no more than 1,350 BTU / lb, or no more than 1,300 BTU / lb.

5. The chemical recovery method of any one of claims 1-4, wherein the fluid energy source has a pressure of no more than 400 psi, no more than 350 psi, no more than 300 psi, no more than 250 psi, no more than 200 psi, no more than 150 psi, no more than 100 psi, no more than 75 psi, no more than 50 psi, no more than 25 psi or no more than 10 psi.

6. The chemical recovery method according to any one of claims 1-5, wherein the fluid energy source has a temperature of at least 90°C, at least 100°C or at least 110°C.

7. The chemical recovery method according to any one of claims 1-6, wherein the fluid energy source has a temperature of no more than 250°C, no more than 240°C, no more than 230°C, no more than 220°C, no more than 210°C, no more than 200°C, no more than 190°C, no more than 180°C, no more than 170°C, no more than 160°C or no more than 150°C.

8. The chemical recovery method according to any one of claims 1 to 7, wherein the fluid energy source comprises flue gas, steam, oil and / or water.

9. The chemical recovery method according to any one of claims 1 to 8, wherein the fluid energy source comprises flue gas.

10. The chemical recovery method according to claim 9, wherein the flue gas is pyrolysis reactor flue gas, cracking furnace flue gas, steam generator flue gas and / or gas turbine flue gas.

11. The chemical recovery method according to any one of claims 1 to 10, wherein the fluid energy source comprises a quench stream from a quench system.

12. The chemical recovery method according to any one of claims 1 to 11, wherein the preheating of step (c) forms a cooled fluid energy source, and the method further comprises recovering carbon dioxide from the cooled fluid energy source.

13. The chemical recovery process of claim 12, wherein the cooled flue gas stream has a temperature of no more than 100°C, no more than 95°C, no more than 90°C, no more than 85°C, or no more than 80°C.

14. A chemical recovery method comprising: (a) liquefying at least a portion of the waste plastic in a liquefaction system to form liquefied waste plastic; (b) pyrolyzing at least a portion of the liquefied waste plastic to produce a pyrolysis effluent; (c) preheating at least a portion of the initial stream with the flue gas stream to form a cooled flue gas stream, wherein the initial stream comprises one or more of the following: (i) said waste plastics subjected to said liquefaction of step (a), (ii) a combustion fuel stream for generating heat for said liquefaction of step (a) or said pyrolysis of step (b), or (iii) a combustion air stream for generating heat for said liquefaction of step (a) or said pyrolysis of step (b); and (d) recovering a carbon dioxide stream from at least a portion of said cooled flue gas stream.

15. The chemical recovery process according to claim 14, wherein the cooled flue gas stream is vented after the recovery in step (d).

16. The chemical recovery process of claim 14 or 15, wherein the flue gas stream has an enthalpy of at least 800 BTU / lb, at least 850 BTU / lb, at least 900 BTU / lb, at least 950 BTU / lb, at least 1,000 BTU / lb, at least 1,050 BTU / lb, at least 1,100 BTU / lb, or at least 1,050 BTU / lb.

17. The chemical recovery process of any one of claims 14-16, wherein the flue gas stream has an enthalpy of no more than 1,600 BTU / lb, no more than 1,550 BTU / lb, no more than 1,500 BTU / lb, no more than 1,450 BTU / lb, no more than 1,400 BTU / lb, no more than 1,350 BTU / lb, or no more than 1,300 BTU / lb.

18. A chemical recovery method according to any one of claims 14-17, wherein the flue gas stream has a pressure of no more than 400 psi, no more than 350 psi, no more than 300 psi, no more than 250 psi, no more than 200 psi, no more than 150 psi, no more than 100 psi, no more than 75 psi, no more than 50 psi, no more than 25 psi or no more than 10 psi.

19. The chemical recovery process according to any one of claims 14-18, wherein the flue gas stream has a temperature of at least 80°C, at least 90°C, at least 100°C or at least 110°C.

20. The chemical recovery process of any one of claims 14-19, wherein the flue gas stream has a temperature of no more than 260°C, no more than 240°C, no more than 230°C, no more than 220°C, no more than 210°C, no more than 200°C, no more than 190°C, no more than 180°C, no more than 170°C, no more than 160°C or no more than 150°C.

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