Integration of Polymeric Waste Co-Processing in Cokers to Produce Circular Chemical Products from Coker Gas Oil

This application claims the benefit of and priority to U.S. Provisional Application No. 63/374,946 filed Sep. 8, 2022, the disclosure of which is incorporated herein by reference.

in cokers to produce circular chemical products from coker gas oil.

Processing of polymeric waste is a subject of increasing importance. It is desirable to have a processing pathway that allows for production of circular chemical products. Specifically, it is desirable to produce circular chemical products through a processing pathway that includes polymeric waste recycling. Although dedicated processing systems could be used for polymeric waste recycling, such dedicated systems require substantial initial capital costs and a constant supply of waste feedstock. Thus, it is desirable to leverage an existing processing unit to be able to co-process polymeric waste into feedstock for production of circular chemical products.

Disclosed herein is an example method of producing circular chemical products comprising: providing a coker gas oil that is at least partially derived from polymeric waste, wherein the coker gas oil has a paraffin content of about 5 wt % to about 50 wt %, a sulfur content of about 0.1 wt % to about 7 wt %, and a halide content of about 0.1 wppm to about 5 wppm; and converting the coker gas oil into at least a polymer.

Further disclosed herein is an example method of producing circular chemical products comprising: providing a coker gas oil that is at least partially derived from polymeric waste, wherein the coker gas oil has a paraffin content of about 5 wt % to about 50 wt %, a sulfur content of about 0.1 wt % to about 7 wt %, and a halide content of about 0.1 wppm to about 5 wppm; hydroprocessing at least a portion of the coker gas oil to form at least a hydroprocessing effluent; steam cracking at least a portion of the hydroprocessing effluent to form at least a steam cracking effluent; recovering olefins from the steam cracking effluent; and polymerizing at least a portion of the olefins to form at least polyolefins.

These and other features and attributes of the disclosed methods and systems of the present disclosure and their advantageous applications and/or uses will be apparent from the detailed description which follows.

In various embodiments, systems and methods are provided for chemical recycling of polymeric waste, such as plastic waste. In some embodiments, the polymeric waste is co-processed in a coker to produce coker products, including coker gas oil. Example embodiments further include includes production of circular chemical products from the coker gas oil that are at least partially derived from polymeric waste. In some embodiments, the circular products include circular olefins, which can be further processed to produce circular polyolefins.

Circular chemical products are chemical products derived from polymeric waste wherein the molecules of the chemical product can be attributed to the polymers in the polymeric waste, such as by crediting, allocating offsetting for other hydrocarbons, and/or substituting for other hydrocarbons in a mass or energy balance for a system. Circular chemical products include circular monomers, circular aromatics, and circular polymers, among others. Polymers that are certified for their circularity by third party certification may be referred to as certified circular. One example of such a certification is the mass balance chain of custody method set forth by the International Sustainability and Carbon Certification.

Coker gas oil is a coker effluent fraction that is formed in the coker with a T10 distillation point of 225° C. or higher and a T90 distillation point of 650° C. or less. Coker gas oil is a mixture of many different hydrocarbons, including paraffins, olefins, and aromatics. Coker gas oil can include hydrocarbons ranging from 8 carbon atoms to 70 carbon atoms. Coker gas oil is typically considered “heavy” if it has a boiling point range of 340° C. to 525° C. Coker gas oil is typically considered “light” if it has a boiling point range of 220° C. to 345° C. In some embodiments, coker gas oil is separated into light and heavy fractions.

Coker gas oil typically has a number of uses, including as a fuel that can be burned in a furnace or boiler for generation of energy. Coker gas oil can also be upgraded, for example, in a fluid catalytic cracking (“FCC”) unit. However, while coker gas oil can be used as an FCC feedstock, coker gas oil typically presents challenges making it use as a feedstock for subsequent processing. For example, coker gas oil typically contains levels of sulfur that results in poor quality of resultant chemical products as well as posing challenges with process reliability. In addition, metals (e.g., lead, iron, and copper), aromatic content (e.g., multi-ring aromatics) and olefin content of the coker gas oil relative to paraffins also poses challenges to process reliability while also making chemical production less cost effective. Accordingly, coker gas oil typically must undergo extension pre-treatment, including hydrotreating, amine/caustic treatment, and/or water wash prior to chemical production, as well as fractionation for concentrating olefins prior to polymerization.

In one or more embodiments, the chemical products are produced from coker gas oil that is at least partially derived from polymeric waste. In some embodiments, the coker gas oil is produced by co-processing of polymeric waste with a conventional coker feedstock. Accordingly, at least a portion of the chemical products produced from the coker gas oil can be considered circular chemical products. Circular chemical products can have inherently higher value than chemical products produced from conventional coker gas oil, thus providing improved economics for chemical production from coker gas, oil for example, by having increased olefin content with reduced paraffin content, as well as lower aromatic content. In addition, the co-processing of the polymeric waste should also provide coker gas oil with reduced sulfur content. Advantageously, the reduction in sulfur and paraffin content from co-processing of polymeric waste should increase the value of coker gas oil for subsequent chemical production, for example, by reducing the extent of pre-treatment and/or fractionation that may be required.

In addition, processing of the coker gas oil that is at least partially derived from polymeric waste to form chemical products presents unique challenges. For example, coker gas oil from polymeric waste has increased halides as compared to conventional coker gas oil. The increased halide content is from halides present in the polymeric waste (e.g., polyvinyl chloride, polyvinylidene chloride, fire retardants, inks, dyes, fluoropolymer processing aids) that at least a portion of which ultimately end up in the coker gas. Additionally, the coker gas oil can also include increased levels of oxygen-containing compounds (e.g., ketones esters, acids, aldehydes, and combinations thereof) and nitrogen-containing compounds (e.g., pyrroles, pyridines, amines, amides, and combinations thereof) from coking of polymer waste. Accordingly, example embodiments include treatment of the coker gas oil for removal of these compounds, including halides, oxygen, and nitrogen.

Accordingly, present embodiments utilize the coker gas oil that is at least partially derived from polymeric waste as a feedstock for chemical production. This integration of a coker with chemical production allows the polymeric waste to be chemically recycled into chemical products, such as monomers (e.g., olefins), aromatics, polymers, synthetic elastomers and rubbers, plastic additives, epoxies, and resins, and specialty fluids, such as isopropyl alcohol, oxo-alcohols, detergents, and lubricants.

illustrates an example configuration for chemical recycling of polymeric waste that includes an integrated processfor coking of polymeric waste with polymer production. As illustrated, the integrated processincludes a coking stage, a hydroprocessing stage, a steam cracking stage, an olefins recovery stage, and a polymerization stage.

In, a waste feedstockand one or more conventional coking feedstocksare fed into the coking stage. The waste feedstockincludes polymeric waste. The one or more conventional coking feedstocksinclude, for example, a heavy oil with a T10 distillation point of 343° C. or greater, such as petroleum vacuum resid. Coking stagecorresponds to any suitable coking for coking the polymeric waste, including a delayed coker, a fluidized coker, flexicoker, or a combination thereof. In the coking stage, the combined feedstock of the waste feedstockand the one or more conventional coking feedstocksare processed to form at least a coking effluent. In the example shown in, the coking effluent can be separated to form a coker gas fractionand a coker liquids fraction, which may be further separated, for example, into coker a naphtha fractionand a coker gas oil fraction. In some embodiments, one or more of the fractions from the coking stagemay be combined. In some embodiments, one or more additional fractions may be produced in the coking stage. A coke productalso shown, but it should be understood that the coke productis typically withdrawn from a coker separately from the coker effluent or gasified in a flexicoker, for example.

The coker gas oil fractionthat is at least partially derived from polymeric waste can then be passed into the hydroprocessing stage. Hydroprocessing stagecorresponds to any suitable process for hydroprocessing the coker gas oil, including hydrotreatment, hydrocracking, catalytic dewaxing and/or hydroisomerization, aromatic saturation. In some embodiments, hydroprocessing stagecorresponds to hydrotreatment of at least a portion of the coker gas oil fractionthat treatment of the coker gas oil with hydrogen in the presence of a hydroprocessing catalyst, for example at elevated temperatures and/or pressures. A number of different reactions can occur during hydrotreatment, including hydrodesulfurization, hydrodenitrogenation, and/or hydrogenation, among others. Hydrotreatment can reduce halides, sulfur, and metal levels in the coker gas oil, as well as nitrogen-and oxygen-containing compounds, in addition to other impurities. In some embodiments, the coker gas oil fractionis co-processed in the hydroprocessing stagewith one or more additional gas oils, which may be from different sources. In the example shown in, all of the coker gas oil fractionfrom the coking stageis passed into the hydroprocessing stage. In other embodiments, a portion of the coker gas oil fractionfrom the coking stageis used for another purpose with another portion of the coker gas oil fractionpassed to the hydroprocessing stage.

The hydroprocessing effluentthat is at least partially derived from polymeric waste can then be passed into the steam cracking stage. Steam cracking stagecorresponds to any suitable process for steam cracking saturated hydrocarbons into small hydrocarbons, including olefins such as ethylene, propylene, butylene (e.g., isobutylene), and butadiene, among others. For example, the hydroprocessing effluentmay be diluted with steam and heated to reaction temperatures for steam cracking. In some embodiments, the hydroprocessing effluentfrom co-processing of the coker gas oil is co-processed in the steam cracking stagewith one or more additional steam cracking feeds. In the example shown in, all of the hydroprocessing effluentfrom the hydroprocessing stageis passed into the steam cracking stage. In other embodiments, a portion of the hydroprocessing effluentfrom the hydroprocessing stageis used for another purpose with another portion of the hydroprocessing effluentpassed to the steam cracking stage.

After the steam cracking stage, the steam cracking effluentthat is at least partially derived from polymeric waste can then be passed into the olefins recovery stage. In the example shown in, all of the steam cracking effluentfrom the steam cracking stageis passed into the olefins recovery stage. In other embodiments, a portion of the steam cracking effluentfrom the steam cracking stageis used for another purpose with another portion of the steam cracking effluentpassed to the olefins recovery stage. In some embodiments, the steam cracking effluent(or portion thereof) may be treated, for example, to at least partially remove one or more components (e.g., halides, oxygen, nitrogen) before the olefins recovery stage. In the olefins recovery stage, olefins are separated from the steam cracking effluentto form at least an olefins streamand an additional product stream. The olefins streamdoes not necessarily include 100% olefins but should generally include a substantial portion of olefins, for example, 50 wt %, 60 wt %, 80 wt %, 90 wt %, 95 wt %, or more of olefins. Separation of the olefins from the steam cracking effluentcan occur in one or more vessels and/or one or more different operations. For example, the steam cracking effluentcan be fractionated or otherwise separated to form at least the olefins streamand additional products stream. At least a portion of the olefins separated from the steam cracking effluentinclude circular olefins, such as circular ethylene, circular propylene, and circular butylene (e.g., circular butylene), and circular butadiene, among others. Circular olefins can be attributed, for example, to polymers in the polymeric waste. In some embodiments, the olefins streamcan be separated into one or more additional fractions, such as an ethylene fraction including circular ethylene, a butylene fraction including circular butylene, a propylene fraction including circular propylene, and/or a butadiene fraction including circular butadiene, among others. At least a portion of the products in the additional product streaminclude circular products, such as aromatics, including benzene, toluene, xylene, and styrene. Additional circular products include, for example, cyclohexane, cyclopentadiene, and dicyclopentadiene. In some embodiments, the additional product streamis separated into one or more fractions, such as an aromatics stream.

The olefins streamfrom the olefins recovery stagecan then be passed to a polymerization stagefor production of chemical products, such as polymer products. For example, an ethylene fraction, propylene fraction, and/or butylene fraction can be separately passed to a polymerization stage. Polymerization stagecorresponds to any suitable polymerization process for bonding two or more olefins, including chain growth propagation, step-growth, and condensation polymerization. The polymerization processes may be in the solution, slurry, or gas-phase, among others. In some embodiments, the polymer productsinclude polyolefins. At least a portion of the polymer productsproduced in the polymerization stageinclude circular polymers, such as circular polyethylene, circular polypropylene, circular polybutylene (e.g., circular polyisobutylene), circular polybutadiene, circular polyethylene terephthalate, circular polystyrene, circular polycarbonate, and circular polycaprolactam, among others. Circular polymers can be attributed, for example, to polymers in the polymeric waste. In the example shown in, all of the olefins streamfrom the olefins recovery stageis passed into the polymerization stage. In other embodiments, a portion of the olefins streamfrom the olefins recovery stageis used for another purpose with another portion of the olefins streampassed to the polymerization stage.

illustrates another example configuration for chemical recycling of polymeric waste that includes an integrated processfor coking of polymeric waste with polymer production. The embodiment ofis similar toexcept the integrated processfurther includes a hydrotreating stageand a hydrocracking stage. As illustrated, the integrated processincludes a coking stage, a hydrotreating stage, a hydrocracking stage, a steam cracking stage, an olefins recovery stage, and a polymerization stage.

In, a waste feedstockand one or more conventional coking feedstocksare fed into the coking stage. The waste feedstockincludes polymeric waste. The one or more conventional coking feedstocksinclude, for example, a heavy oil with a T10 distillation point of 343° C. or greater, such as petroleum vacuum resid. Coking stagecorresponds to any suitable coking for coking the polymeric waste, including a delayed coker, a fluidized coker, flexicoker, or a combination thereof. In the coking stage, the combined feedstock of the waste feedstockand the one or more conventional coking feedstocksare processed to form at least a coking effluent. In the example shown in, the coking effluent can be separated to form a coker gas fractionand a coker liquids fraction, which may be further separated, for example, into coker a naphtha fractionand a coker gas oil fraction. In some embodiments, one or more of the fractions from the coking stagemay be combined. In some embodiments, one or more additional fractions may be produced in the coking stage. A coke productalso shown, but it should be understood that the coke productis typically withdrawn from a coker separately from the coker effluent or gasified in a flexicoker, for example.

The coker gas oil fractionthat is at least partially derived from polymeric waste can then be passed into the hydrotreating stage. Any suitable technique for hydrotreatment may be used in accordance with one or more embodiments. In some embodiments, hydrotreatment of at least a portion of the coker gas oil fraction includes treatment of the coker gas oil with hydrogen in the presence of a hydrotreatment catalyst, for example at elevated temperatures and/or elevated pressures. A number of different reactions can occur during hydrotreatment, including hydrodesulfurization, hydrodenitrogenation, and/or hydrogenation, among others. Hydrotreatment can reduce sulfur and metal levels in the coker gas oil, as well as nitrogen-and oxygen-containing compounds. In the example shown in, all of the coker gas oil fractionfrom the coking stageis passed into the hydrotreating stage. In other embodiments, a portion of the coker gas oil fractionfrom the coking stageis used for another purpose with another portion of the coker gas oil fractionpassed to the hydrotreating stage.

The hydrotreated effluentthat is at least partially derived from polymeric waste can then be passed into the hydrocracking stage. Hydrocracking generally includes treatment of the hydrotreated effluentwith hydrogen in the presence of a hydrocracking catalyst. In hydrocracking larger hydrocarbon molecules are broken down into smaller molecules, for example, by addition of hydrogen under pressure and in the presence of a catalyst. Additional reactions can occur in hydrocracking including, for example, hydrodesulfurization, hydrodenitrogenation, and/or hydrogenation, among others. Hydrocracking can reduce sulfur and metal levels in the coker gas oil, as well as nitrogen-and oxygen-containing compounds, in addition to other impurities. In the example shown in, all of the hydrotreated effluentfrom the hydrotreating stageis passed into the hydrocracking stage. In other embodiments, a portion of the hydrotreated effluentfrom the hydrotreating stageis used for another purpose with another portion of the hydrotreated effluentpassed to the hydrocracking stage.

The hydrocracking effluentfrom the hydrocracking stagethat is at least partially derived from polymeric waste can then be passed to the steam cracking stage. Steam cracking stagecorresponds to any suitable process for steam cracking saturated hydrocarbons into small hydrocarbons, including olefins such as ethylene, propylene, butylene (e.g., isobutylene), and butadiene, among others. For example, the hydrocracking effluentmay be diluted with steam and heated to reaction temperatures for steam cracking. In the example shown in, all of the hydrocracking effluentfrom the hydrocracking stageis passed into the steam cracking stage. In other embodiments, a portion of the hydrocracking stagefrom the hydrocracking stageis used for another purpose with another portion of the hydrocracking stagepassed to the steam cracking stage.

After the steam cracking stage, the steam cracking effluentthat is at least partially derived from polymeric waste can then be passed into the olefins recovery stage.

In the example shown in, all of the steam cracking effluentfrom the steam cracking stageis passed into the olefins recovery stage. In other embodiments, a portion of the steam cracking effluentfrom the steam cracking stageis used for another purpose with another portion of the steam cracking effluentpassed to the olefins recovery stage. In some embodiments, the steam cracking effluent(or portion thereof) may be treated, for example, to at least partially remove one or more components (e.g., halides, oxygen, nitrogen) before the olefins recovery stage. In the olefins recovery stage, olefins are separated from the steam cracking effluentto form at least an olefins streamand an additional product stream. The olefins streamdoes not necessarily include 100% olefins but should generally include a substantial portion of olefins, for example, 50 wt %, 60 wt %, 80 wt %, 90 wt %, 95 wt %, or more of olefins. Separation of the olefins from the steam cracking effluentcan occur in one or more vessels and/or one or more different operations. For example, the steam cracking effluentcan be fractionated or otherwise separated to form at least the olefins streamand additional products stream. At least a portion of the olefins separated from the steam cracking effluentinclude circular olefins, such as circular ethylene, circular propylene, and circular butylene (e.g., circular butylene), and circular butadiene, among others. Circular olefins can be attributed, for example, to polymers in the polymeric waste. In some embodiments, the olefins streamcan be separated into one or more additional fractions, such as an ethylene fraction including circular ethylene, a butylene fraction including circular butylene, a propylene fraction including circular propylene, and/or a butadiene fraction including circular butadiene, among others. At least a portion of the products in the additional product streaminclude circular products, such as aromatics, including benzene, toluene, xylene, and styrene. Additional circular products include, for example, cyclohexane, cyclopentadiene, and dicyclopentadiene. In some embodiments, the additional product streamis separated into one or more fractions, such as an aromatics stream.

The olefins streamfrom the olefins recovery stagecan then be passed to a polymerization stagefor production of chemical products, such as polymer products. For example, an ethylene fraction, propylene fraction, and/or butylene fraction can be separately passed to a polymerization stage. Polymerization stagecorresponds to any suitable polymerization process for bonding two or more olefins, including chain growth propagation, step-growth, and condensation polymerization. The polymerization processes may be in the solution, slurry, or gas-phase, among others. In some embodiments, the polymer productsinclude polyolefins. At least a portion of the polymer productsproduced in the polymerization stageinclude circular polymers, such as circular polyethylene, circular polypropylene, circular polybutylene (e.g., circular polyisobutylene), circular polybutadiene, circular polyethylene terephthalate, circular polystyrene, circular polycarbonate, and circular polycaprolactam, among others. Circular polymers can be attributed, for example, to polymers in the polymeric waste. In the example shown in, all of the olefins streamfrom the olefins recovery stageis passed into the polymerization stage. In other embodiments, a portion of the olefins streamfrom the olefins recovery stageis used for another purpose with another portion of the olefins streampassed to the polymerization stage.

illustrates another example configuration for chemical recycling of polymeric waste that includes an integrated processfor coking of polymeric waste with polymer production. As illustrated, the integrated processincludes a coking stage, a fluid catalytic cracking (“FCC”) stage, an olefins recovery stage, and a polymerization stage.

In, a waste feedstockand one or more conventional coking feedstocksare fed into the coking stage. The waste feedstockincludes polymeric waste. The one or more conventional coking feedstocksinclude, for example, a heavy oil with a T10 distillation point of 343° C. or greater, such as petroleum vacuum resid. Coking stagecorresponds to any suitable coking for coking the polymeric waste, including a delayed coker, a fluidized coker, flexicoker, or a combination thereof. In the coking stage, the combined feedstock of the waste feedstockand the one or more conventional coking feedstocksare processed to form at least a coking effluent. In the example shown in, the coking effluent can be separated to form a coker gas fractionand a coker liquids fraction, which may be further separated, for example, into a coker naphtha fractionand a coker gas oil fraction. In some embodiments, one or more of the fractions from the coking stagemay be combined. In some embodiments, one or more additional fractions may be produced in the coking stage. A coke productis also shown, but it should be understood that the coke productis typically withdrawn from a coker separately from the coker effluent or gasified in a flexicoker, for example.

The coker gas oil fractionthat is at least partially derived from polymeric waste can then be passed into the FCC stage. FCC stagecorresponds to any suitable process for fluid catalytic cracking of hydrocarbons into smaller hydrocarbons, including olefins such as ethylene, propylene, butylene (e.g., isobutylene), and butadiene, among others. Fluid catalytic cracking includes, for example, heating of the feed of the coker gas oil fractionand contacting the feed with a hot, powdered catalyst. The FCC stagegenerates at least FCC gasand FCC liquids. The FCC gasincludes C-Colefins, such as ethylene, propylene, and butylene. The FCC liquids includes hydrocarbons, such as, for example, a naphtha fraction and heavier hydrocarbons. In the example shown in, all of the coker gas oil fractionfrom the coking stageis passed into the FCC stage. In other embodiments, a portion of the coker gas oil fractionfrom the coking stageis used for another purpose, such as fuel, with another portion of the coker gas oil fractionpassed to the FCC stage.

After the FCC stage, the FCC gascan be passed to an olefins recovery stage. In the olefins recovery stage, olefins are separated from the FCC gasto form at least an olefins streamand a paraffins stream. It should be understood that separation of the olefins from the FCC gascan occur in one or more vessels and/or one or more different operations. For example, the FCC gascan be fractionated or otherwise separated to form at least the olefins streamand paraffins stream. At least a portion of the olefins separated from the FCC gasinclude circular olefins, such as circular ethylene, circular propylene, and circular butylene (e.g., circular butylene), and circular butadiene, among others. Circular olefins can be attributed, for example, to polymers in the polymeric waste. In some embodiments, the olefins streamcan be separated into one or more additional fractions, such as an ethylene fraction including circular ethylene, a butylene fraction including circular butylene, a propylene fraction including circular propylene, and/or a butadiene fraction including circular butadiene, among others.

The olefins streamfrom the olefins recovery stagecan then be passed to a polymerization stagefor production of chemical products, such as polymer products. For example, an ethylene fraction, propylene fraction, and/or butylene fraction can be separately passed to a polymerization stage. Polymerization stagecorresponds to any suitable polymerization process for bonding two or more olefins, including chain growth propagation, step-growth, and condensation polymerization. The polymerization processes may be in the solution, slurry, or gas-phase, among others. In some embodiments, the polymer productsinclude polyolefins. At least a portion of the polymer productsproduced in the polymerization stageinclude circular polymers, such as circular polyethylene, circular polypropylene, circular polybutylene (e.g., circular polyisobutylene), circular polybutadiene, circular polyethylene terephthalate, circular polystyrene, circular polycarbonate, and circular polycaprolactam, among others. Circular polymers can be attributed, for example, to polymers in the polymeric waste. In the example shown in, all of the olefins streamfrom the olefins recovery stageis passed into the polymerization stage. In other embodiments, a portion of the olefins streamfrom the olefins recovery stageis used for another purpose with another portion of the olefins streampassed to the polymerization stage.

illustrates another example configuration for chemical recycling of polymeric waste that includes an integrated processfor coking of polymeric waste with polymer production. As illustrated, the integrated processincludes a coking stage, a partial oxidation stage, and a hydroformylation stage.

In, a waste feedstockand one or more conventional coking feedstocksare fed into the coking stage. The waste feedstockincludes polymeric waste. The one or more conventional coking feedstocksinclude, for example, a heavy oil with a T10 distillation point of 343° C. or greater, such as petroleum vacuum resid. Coking stagecorresponds to any suitable coking for coking the polymeric waste, including a delayed coker, a fluidized coker, flexicoker, or a combination thereof. In the coking stage, the combined feedstock of the waste feedstockand the one or more conventional coking feedstocksare processed to form at least a coking effluent. In the example shown in, the coking effluent can be separated to form a coker gas fractionand a coker liquids fraction, which may be further separated, for example, into a coker naphtha fractionand a coker gas oil fraction. In some embodiments, one or more of the fractions from the coking stagemay be combined. In some embodiments, one or more additional fractions may be produced in the coking stage. A coke productis also shown, but it should be understood that the coke productis typically withdrawn from a coker separately from the coker effluent or gasified in a flexicoker, for example.

The coker gas oil fractionthat is at least partially derived from polymeric waste can then be passed into the partial oxidation stage. The partial oxidation stagecorresponds to any suitable process for partial oxidation including, for example, catalytic and thermal partial oxidation. In partial oxidation, the coker gas oil fractionis partially combusted with oxygen to create a hydrogen-containing syngas. The oxidation effluentgenerated in the partial oxidation stageincludes, for example, carbon monoxide and hydrogen. In some embodiments, the oxidation effluent includes carbon monoxide and hydrogen in an amount of at least 70 wt %, at least 80 wt %, or at least 90 wt %. In the example shown in, all of the coker gas oil fractionfrom the coking stageis passed into the partial oxidation stage. In other embodiments, a portion of the coker gas oil fractionfrom the coking stageis used for another purpose, such as fuel, with another portion of the coker gas oil fractionpassed to the partial oxidation stage.

After the partial oxidation stage, the oxidation effluentcan be passed to a hydroformylation stage. In the hydroformylation stage, the oxidation effluent can be used for production of a variety of chemical products. In some embodiments, the syngas can be combined with olefins over a hydroformylation catalyst to produce oxo alcohols. A variety of chemical products and polymer precursors can also be produced, in some embodiments, from the syngas in the oxidation effluentusing the Fischer-Tropsch process. In some embodiments, oxidation effluentis purified for hydrogen recovery. As illustrated, a product streamis withdrawn from the hydroformylation stage. Product streamincludes, for example, oxo alcohols. In the example shown in, all of the oxidation effluentfrom the coking stageis passed into the hydroformylation stage. In other embodiments, a portion of the oxidation effluentfrom the partial oxidation stageis used for another purpose, such as fuel, with another portion of the oxidation effluentpassed to the hydroformylation stage.

In accordance with present embodiments, coking can be used to process a waste feedstock to produce coking products. In some embodiments, the waste feedstock is co-processed with a conventional coking feedstock.

The waste feedstock for coking can include or consist essentially of one or more types of polymers, such as polymers corresponding to plastic waste. The systems and methods described herein can be suitable for processing polymeric waste corresponding to a single type of polymer and/or polymeric waste corresponding to a plurality of polymers. In aspects where the waste feedstock consists essentially of polymers, the feedstock can include one or more types of polymers as well as any additives, modifiers, packaging dyes, and/or other components typically added to a polymer during and/or after formulation. The waste feedstock can further include components (e.g., paper) typically found in polymeric waste.

In some embodiments, the waste feedstock includes polymeric waste obtained from any source including, but not limited to, municipal, industrial, commercial or consumer sources. In some embodiments, the waste feedstock includes post-consumer use plastics. The polymeric waste further may include plastics obtained from a common source or from mixed sources, including mixed plastic waste obtained from municipal or regional sources and/or from waste streams of PET, HDPE, LDPE, LLDPE, polypropylene, and/or polystyrene. Furthermore, the waste feedstock may include thermoplastic elastomers and thermoset rubbers, such as from tires and other articles made from natural rubber, polybutadiene, styrene-butadiene, butyl rubber and EPDM.

Even further, examples of suitable waste feedstocks may include any of various used polymeric articles without limitation. Some examples of the many types of polymeric articles may include: films (including cast, blown, and otherwise), sheets, fibers, woven and nonwoven fabrics, furniture (e.g., garden furniture), sporting equipment, bottles, food and/or liquid storage containers, transparent and semi-transparent articles, toys, tubing and pipes, sheets, packaging, bags, sacks, coatings, caps, closures, crates, pallets, cups, non-food containers, pails, insulation, and/or medical devices. Further examples include industrial waste streams, such as linear alpha olefins and polypropylene heavy streams (e.g., >50 wt %). Further examples include automotive, aviation, boat and/or watercraft components (e.g., bumpers, grills, trim parts, dashboards, instrument panels and the like), wire and cable jacketing, agricultural films, geomembranes, playground equipment, and other such articles, whether blow molded, roto-molded, injection-molded, or the like. Any of the foregoing may include mixtures of polymeric and non-polymeric items (e.g., packaging or other articles may include inks, paperboards, papers, metal deposition layers, and the like). The ordinarily skilled artisan will appreciate that such polymeric articles may be made from any of various polymer and/or non-polymer materials, and that the polymer materials may vary widely (e.g., ethylene-based, propylene-based, butyl-based polymers, and/or polymers based on any Cto Cor even higher olefins, and further including polymers based on any one or more types of monomers, e.g., Cto Cα-olefin, di-olefin, cyclic olefin, etc. monomers). Common examples include ethylene, propylene, butylene, pentene, hexene, heptene, octene, and styrene; as well as multi-olefinic (including cyclic olefin) monomers such as ethylidene norbornene (ENB) and vinylidene norbornene (VNB) (including, e.g., when such cyclic olefins are used as comonomers, e.g., with ethylene monomers).

In various embodiments, the waste feedstock can include one or more nitrogen-containing polymers. Examples of nitrogen-containing polymers include polyamides (such as Nylon 6), polyurethanes, and polynitriles. The nitrogen-containing polymers can correspond to 0.1 wt % to 25 wt % of the waste feedstock (relative to the weight of the waste feedstock), or 1.0 wt % to 25 wt %, or 5.0 wt % to 25 wt %, or 10 wt % to 25 wt %, or 1.0 wt % to 15 wt %, or 5.0 wt % to 15 wt %, or 1.0 wt % to 10 wt %. For example, nitrogen-containing polymers may be in the waste feedstock in an amount of 25 wt % or less, 10 wt % or less, 5 wt % or less, 1 wt % or less, or 0.1 wt % or less.

In some embodiments, the waste feedstock can include one or more chlorine-containing polymers. Examples of chlorine-containing polymers including PVC (polyvinyl chloride) and PVDC (polyvinylidene chloride). In some aspects, the chlorine-containing polymers can correspond to as 0.001 wt % to 15 wt % of the waste feedstock (relative to the weight of the waste feedstock), or 0.1 wt % to 15 wt %, or 1.0 wt % to 15 wt %, or 0.001 wt % to 10 wt %, or 0.1 wt % to 10 wt %, or 1.0 wt % to 10 wt %, or 0.001 wt % to 5.0 wt %, or 0.001 wt % to 1.0 wt %. For example, the chlorine-containing polymers may be in the waste feedstock in an amount of about 15 wt % or less, 10 wt % or less, 5 wt % or less, 1 wt % or less, or 0.1 wt % or less.

In some embodiments, the waste feedstock can include at least one of polyethylene and polypropylene. The polyethylene can correspond to any convenient type of polyethylene, such as high density or low-density versions of polyethylene. Similarly, any convenient type of polypropylene can be used. Additionally or alternately, the waste feedstock can include one or more of polystyrene, polyamide (e.g., nylon), polyethylene terephthalate, and ethylene vinyl acetate. Still other polyolefins can correspond to polymers (including co-polymers) of butadiene, isoprene, and isobutylene. In some embodiments, the polyethylene and polypropylene can be present in the mixture as a co-polymer of ethylene and propylene. More generally, the polyolefins can include co-polymers of various olefins, such as ethylene, propylene, butenes, hexenes, and/or any other olefins suitable for polymerization.

In this discussion, unless otherwise specified, weights of polymers in a feedstock correspond to weights relative to the total polymer content in the feedstock. Any additives and/or modifiers and/or other components included in a formulated polymer are included in this weight. However, the weight percentages described herein exclude any solvents or carriers that might optionally be used to facilitate transport of the polymer into the coker.

In some embodiments, the waste feedstock includes 0.01 wt % to 35 wt % of polystyrene, or 0.1 wt % to 35 wt %, or 1 wt % to 35 wt %, or 0.01 wt % to 20 wt %, or 0.1 wt % to 20 wt %, or 1 wt % to 20 wt %, or 10 wt % to 35 wt %, or 5 wt % to 20 wt %, or 0.01 wt % to 10 wt %, or 0.01 wt % to 1 wt %. In some embodiments, the waste feedstock can also include oxygen-containing polymers, such as polyterephthalates. It is noted that polyamides also contain oxygen as part of the polymer structure. In this discussion, a polymer that includes both oxygen and nitrogen as part of the repeat unit for forming the polymer is defined as a nitrogen-containing polymer for purposes of characterizing the waste feedstock.

In addition to polymers, a waste feedstock can include a variety of other components. Such other components can include additives, modifiers, packaging dyes, and/or other components typically added to a polymer during and/or after formulation. The waste feedstock can further include any components typically found in polymeric waste. Finally, the feedstock can further include a carrier fluid so that the waste feedstock to the cracking process corresponds to a solution or slurry of the polymeric waste.

In embodiments where the waste feedstock is introduced into the coking environment at least partially as solids, having a small particle size can facilitate transport of the solids and/or reduce the likelihood of incomplete conversion. In some embodiments, the waste feedstock includes polymeric waste having a median particle size to 0.01 mm to 50 mm, 0.01 mm to 25 mm, 0.01 mm to 10 mm, 1 mm to 50 mm, 1 mm to 25 mm, 1 mm to 10 mm, 5 mm, or 0.1 mm to 5 mm, or 0.01 mm to 3 mm, or 0.1 mm to 3 mm, or 0.01 mm to 3 mm, or 0.1 mm to 3 mm, or 1 mm to 5 mm, or 1 mm to 3 mm. For determining a median particle size, the particle size is defined as the diameter of the smallest bounding sphere that contains the particle. Additionally or alternately, the polymeric waste in the waste feedstock can be melted and/or pelletized to improve the uniformity of the particle size of the plastic particles. In some embodiments, the polymeric waste has a maximum particles size of 10 mm or less, or 5 mm or less. Additionally or alternately, the polymeric waste can be provided in waste bail. In some embodiments, the waste bale is a composite bale.

It is noted that some types of polymeric waste can also include bio-derived components. For example, some types of plastic labels can include biogenic waste in the form of paper compounds. In some embodiments, 1 wt % to 25 wt % of the waste feedstock can correspond to bio-derived material. Such bio-derived material can also potentially contribute to the nitrogen and/or oxygen content of a waste feedstock.

Optionally, a carrier fluid can also be included in the waste feedstock to assist with introducing the polymeric waste into the cracking environment. For introduction into a cracking environment, it can be convenient for the feedstock to be in the form of a slurry. If a carrier fluid is used for transporting the waste feedstock, any suitable fluid can be used. Examples of suitable carrier fluids can include (but are not limited to) a wide range of petroleum or petrochemical products. For example, some suitable carrier fluids include crude oil, naphtha, kerosene, diesel, light or heavy cycle oils, catalytic slurry oil, and gas-oils. Other potential carrier fluids can correspond to naphthenic and/or aromatics solvents, such as toluene, benzene, methylnaphthalene, cyclohexane, methylcyclohexane, and mineral oil. Still other carrier fluids can correspond to refinery fractions, such as a gas oil fraction or naphtha fraction from a coker. As yet another example, a distillate and/or gas oil boiling range fraction can be used that generated by cracking of the waste feedstock, either alone or with an additional feedstock.

In various embodiments, coking is used to co-process a combined feedstock corresponding to a mixture of a conventional coking feedstock and a waste feedstock. In some embodiments, the conventional coking feedstock is used as the carrier fluid for the waste feedstock. The conventional coking feedstock can correspond to one or more types of petroleum and/or renewable feeds with a suitable boiling range for cracking, such as processing in a coker. The amount of waste feedstock in the combined feedstock can correspond to 1 wt % to 50 wt %, 3 wt % to 50 wt %, 10 wt % to 50 wt %, 25 wt % to 50 wt %, 1 wt % to 25 wt %, 1 wt % to 10 wt %, 1 wt % to 5 wt %, 1 wt % to 3 wt %, 3 wt % to 25 wt %, 10 wt % to 25 wt %, 3 wt % to 15 wt % by weight of the combined feedstock. The conventional coking feedstock can correspond to 50% to 99% by weight of the combined feedstock to the coker.