Supercritical fluid extraction of post-consumer recyclate

Abstract

A method for recycling plastic waste including the step of extracting and separating (i) post- consumer recycled (PCR) resin components, (ii) post-industrial recycled (PIR) resin components, or both from plastic waste with a supercritical fluid, wherein the plastic waste is selected from the group consisting of post-consumer recyclate and post-industrial recyclate.

Description

SUPERCRITICAL FLUID EXTRACTION OF POST-CONSUMER RECYCLATEFIELD OF THE INVENTION

[0001] In general, the present disclosure relates to the field of chemistry. More specifically, the present disclosure relates to post-consumer recyclate. In particular, the present disclosure relates to supercritical fluid extraction of post-consumer recyclate and products prepared therefrom.BACKGROUND OF THE INVENTION

[0002] The downside to the demand for polyolefin plastics is an increase in plastic waste. As such, there is considerable interest in developing methods to recycle plastic waste. In addition to reducing the amount of plastic waste, other benefits of recycling plastic waste include reducing carbon footprint, consuming less energy, improving water consumption, and using less raw materials.

[0003] In many instances, before plastic waste is recycled and turned into usable resin, the plastic materials are gathered and sent through a process to produce plastic resin pellets. In some instances, the plastics recycling system is a mechanical recycling system, including the steps of sorting, cleaning, shredding, melting, and remolding.

[0004] In some instances, the resulting plastic resin pellets are made from or containing polyolefins, non-polyolefinic polymers, and other contaminants. In some instances, the non- polyolefinic polymers or the other contaminants are present in an amount that adversely affects the properties of the plastic resin pellets. In some instances, the non-polyolefinic polymers or the other contaminants provide stress points in articles made from or containing the plastic resin pellets.BRIEF SUMMARY OF THE INVENTION

[0005] In a general embodiment, the present disclosure provides a method for recycling plastic waste including the step of extracting and separating (i) post-consumer recycled (PCR) resin components, (ii) post-industrial recycled (PIR) resin components, or both from plastic waste with a supercritical fluid, wherein the plastic waste is selected from the group consisting of postconsumer recyclate and post-industrial recyclate.

[0006] In some embodiments, the present disclosure provides a post-consumer recycled resin prepared from a post-consumer recyclate, wherein the resin is selected from the group consisting of polyethylene and polypropylene. In some embodiments, the polyethylene is a high- density polyethylene.

[0007] In some embodiments, the present disclosure provides a post-industrial recycled resin prepared from a post-industrial recyclate, wherein the resin is selected from the group consisting of polyethylene and polypropylene. In some embodiments, the polyethylene is a high- density polyethylene.

[0008] In some embodiments, the present disclosure provides a polymer composition made from or containing resin selected from the group consisting of a post-consumer recycled resin and a post-industrial recycled resin.

[0009] In some embodiments, the present disclosure provides an article of manufacture made from or containing a resin selected from the group consisting of post-consumer recycled resins and post-industrial recycled resins.

[0010] While multiple embodiments are disclosed, still other embodiments will become apparent to those skilled in the art from the following detailed description. As will be apparent, certain embodiments, as disclosed herein, are capable of modifications in various aspects, without departing from the spirit and scope of the claims as presented herein. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.DETAILED DESCRIPTION OF THE INVENTION

[0011] While the provided embodiments will be described more fully hereinafter, these embodiments are provided to satisfy applicable laws and regulations. As such, it will be apparent to those skilled in the art that the embodiments can incorporate changes and modifications without departing from the general scope. This disclosure is intended to include the modifications and alterations in so far as the modifications and alterations come within the scope of the appended claims or the equivalents thereof.

[0012] As used in this specification and the claims, the singular forms “a,” “an,” and “the” include plural referents unless the context dictates otherwise.

[0013] As used in this specification and the claims, the terms “comprising,” “containing,” or “including” mean that at least the named compound, element, material, particle, or method stepis present in the composition, the article, or the method, but does not exclude the presence of other compounds, elements, materials, particles, or method steps even if the other such compounds, elements, materials, particles, or method steps have the same function as that which is named, unless expressly excluded in the claims. It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps before or after the combined recited steps or intervening method steps between those steps expressly identified.

[0014] Moreover, it is also to be understood that the lettering of process steps or ingredients is for identifying discrete activities or ingredients and the recited lettering can be arranged in any sequence, unless expressly indicated.

[0015] For the purpose of the present description and of the claims which follow, except where otherwise indicated, numbers expressing amounts, quantities, percentages, and so forth, are to be understood as being modified by the term “about”. Also, ranges include any combination of the maximum and minimum points disclosed and include any intermediate ranges therein, which may or may not be specifically enumerated herein.

[0016] Definitions

[0017] In the present description, the term “additive composition” refers to a composition made from or containing an additive.

[0018] In the present description, the term “a-olefin” or “alpha-olefin” means an olefin of formula CHz=CH — R, wherein R is a linear or branched alkyl containing from 1 to 10 carbon atoms. In some embodiments, the a-olefin is selected from the group consisting of propylene, 1- butene, 1 -pentene, 1 -hexene, 1 -octene, and 1 -decene.

[0019] In the present description, the term “critical point” refers to the pressure and temperature at which a chemical compound’s liquid and vapor phases become identical, thereby exhibiting zero surface tension. For example, the critical pressure for carbon dioxide is about 73 atm (or about 7.39672 MPa), and the critical temperature for carbon dioxide is about 31 degrees Celsius.

[0020] In the present description, the term “contaminant” refers to any chemical substance present in a post-consumer recyclate (PCR), a post-industrial recyclate (PIR), a post-consumer recycled resin (PCR resin), or a post-industrial recycled resin (PIR resin), wherein the PCR, the PIR, the PCR resin, or the PIR resin is made from or containing a selected polymer and the presence of the chemical substance thereby renders the PCR, the PIR, the PCR resin, or the PIRresin compositionally different from the pure, selected polymer. In some embodiments, the contaminant is present in an amount ranging from parts per billion (ppb) to percentages, based upon the total weight of the PCR, the PIR, the PCR resin, or the PIR resin. In some embodiments, a multiplicity of contaminants is present. In some embodiments, the contaminant is selected from the group consisting of acrylonitrile butadiene styrene (ABS), calcium carbonate, coffee grounds, diapers, dirt, fillers, food stuffs, glass, grass, labels, metals (including aluminum), nylon, other inorganics, other polymers, paper, plant stems, polycarbonates, polyethylene terephthalate (PET), processing additives, property -imparting additives, rubbers, and wood.

[0021] In the present description, the term “elastomer” refers to polymer compounds having rubber-like properties and crystallinity in the range of from about 0 percent to about 20 percent.

[0022] In the present description, the term “first” refers to the order in which a particular species is presented and does not necessarily indicate that a “second” species will be presented. For example, “first polymer composition” refers to the first of at least one polymer composition. The term does not reflect priority, importance, or significance in any other way. Similar terms used that can be used herein include “second,” “third,” “fourth,” etc.

[0023] In the present description, the term “homopolymer” refers to polymers derived from a single monomeric unit. To the extent that a homopolymer is derived from more than a single monomeric unit, the incorporation of additional monomeric units has no measurable effect on the polymer’s primary, secondary or tertiary structure or no effect on the polymer’s physical or chemical properties. In other words, there is no measurable difference between a polymer, comprising 100 weight percent of a first monomeric unit, and a copolymer, including more than a single monomeric unit.

[0024] In the present description, the term “International Code Council (ICC) Certification” refers to products certified as using 100% post consumer resins.

[0025] In the present description, the term “interpolymer” means a polymer prepared by the polymerization of at least two types of monomers or comonomers. The term “interpolymer” includes copolymers, terpolymers, tetrapolymers, and the like. In some embodiments, the term “copolymer” refers to polymers prepared from two different types of monomers or comonomers. In some embodiments, the term “terpolymer” refers to polymers prepared from three different types of monomers or comonomers. In some embodiments, the term “tetrapolymer” refers topolymers prepared from four different types of monomers or comonomers. In some embodiments, the term “copolymer” is used interchangeably with “interpolymer” and refers to polymers made from three or more different types of monomers or comonomers.

[0026] In the present description, the terms “monomer” and “comonomer” are used interchangeably. The terms refer to any compound with a polymerizable moiety that is added to a reactor to produce a polymer. In those instances wherein a polymer is described as made from or containing one or more monomers, for example, a polymer made from or containing propylene and ethylene, the polymer, of course, is made from or containing units derived from the monomers, for example, — CH2 — CH2 — , and not the monomer itself, for example, CH2=CH2.

[0027] In the present description, the term “PCR” refers interchangeably to Post-ConsumerRecycled or Post-Consumer Recyclate, including polymers such as high-density polyethylene (HOPE) and polypropylene (PP), which are recycled and reprocessed into a resin for use in various applications.

[0028] In the present description, the term “PIR” refers interchangeably to Post-Industrial Recycled or Post-Industrial Recyclate.

[0029] In the present description, the term “polymer” means a macromolecular compound prepared by polymerizing monomers of the same or different type. The term “polymer” includes homopolymers, copolymers, terpolymers, interpolymers, and so on.

[0030] In the present description, the term “polymer composition” refers to a composition made from or containing a polymer.

[0031] In the present description, the term “polyolefin” is used herein broadly to include polymers such as polyethylene, ethylene-alpha olefin copolymers (EAO), polypropylene, polybutene, and ethylene copolymers having at least about 50 percent by weight of ethylene polymerized with a lesser amount of a comonomer such as vinyl acetate, and other polymeric resins within the "olefin" family classification.

[0032] Polyolefins can be made by a variety of processes including batch and continuous processes using single, staged, or sequential reactors, slurry, solution, and fluidized bed processes and one or more catalysts including for example, heterogeneous and homogeneous systems and Ziegler, Phillips, metallocene, single-site, and constrained geometry catalysts to produce polymers having different combinations of properties.

[0033] In the present description, the term “post consumer recycled (PCR) resin” refers to the recycled product of waste created by consumers, including high-density polyethylene postconsumer recycled resin (HDPE PCR) and polypropylene post-consumer recycled resin (PP PCR). Among other forms, PCR resins may take the form of granules, pellets, and powders.

[0034] In the present description, the term “post industrial recycled (PIR) resin” refers to the recycled product of waste generated by manufacturers during the preparation of polymer-based products. In the present description, the disclosed, recycling processes for preparing and using PCR resins are extendable to PIR resins.

[0035] In the present description, the term “recycle” refers to the conversion of waste into a reusable material. The waste is created by consumers, in the case of post-consumer waste, or by manufacturers during the preparation of polymer-based products, in the case of post-industrial waste.

[0036] In the present description, the term “room temperature” refers to a temperature of about 25 degrees Celsius.

[0037] In the present description, the term “supercritical fluid” refers to a gas or liquid at conditions above the critical temperature and the critical pressure of the gas or liquid. It is believed that supercritical fluids exhibit a pressure-tunable dissolving power, possess a liquid-like density, and possess gas-like transport properties for extraction. Specifically, the supercritical fluid exhibits gas-like viscosity and diffusion coefficients and can penetrate into a solid matrix due to negligble surface tension and viscosity. It is further believed that the properties of the supercritical fluid near the critical point can be changed by varying the pressure and temperature, thereby allowing selective and faster extraction.

[0038] In the present description, the term “supercritical fluid extraction” refers to a process of using a supercritical fluid as a solvent to separate and extract a component from a composition made from or containing the component.

[0039] In the present description, the term “thermoplastic polymer” means a polymer that softens when exposed to heat and returns to its original condition when cooled to room temperature.

[0040] In the present description, the term “virgin polymers” refers to polymers prepared in polymerization processes from monomers, with or without catalysts or processing aids, and which are yet to be manufactured into first-use consumer or industrial products.

[0041] In a general embodiment, the present disclosure provides a method for recycling plastic waste including the step of extracting and separating (i) post-consumer recycled (PCR) resin components, (ii) post-industrial recycled (PIR) resin components, or both from plastic waste with a supercritical fluid, wherein the plastic waste is selected from the group consisting of postconsumer recyclate and post-industrial recyclate.

[0042] In some embodiments, the method for recycling plastic waste includes the steps of:(a) collecting the plastic waste from residential, commercial, and industrial sites, wherein the plastic waste is selected from the group consisting of postconsumer recyclate and post-industrial recyclate, and made from or containing a polyolefin and a contaminant;(b) extracting and separating the contaminant from the polyolefin with a supercritical fluid, thereby yielding a polymer composition made from or containing the polyolefin;(c) precipitating the polymer composition from the supercritical fluid; and(d) pelletizing the precipitant, thereby forming a pelletized resin selected from the group consisting of a pelletized, post-consumer recycled (PCR) resin and a pelletized, post-industrial recycled (PIR) resin.

[0043] In some embodiments, the method for recycling plastic waste further includes the steps of:(a.i) sorting the plastic waste; and(a.ii) cleaning the plastic waste.

[0044] It is believed that surface-area-to-volume ratio affects the rate of diffusivity. As such and in some embodiments, the method for recycling plastic waste further includes the step of:(a.iii) grinding the plastic waste, thereby yielding a powder made from or containing the polyolefin and the contaminant.

[0045] In some embodiments, the method for recycling plastic waste includes the steps of:(a) collecting the plastic waste from residential, commercial, and industrial sites, wherein the plastic waste is selected from the group consisting of post-consumer recyclate and post-industrial recyclate, and made from or containing a polyolefin and a contaminant;(a.i) sorting the plastic waste;(a.ii) cleaning the plastic waste;(a.iii) grinding the plastic waste, thereby yielding a powder made from or containing the polyolefin and the contaminant;(b) extracting and separating the contaminant from the polyolefin with a supercritical fluid through supercritical fluid extraction of the powder, thereby yielding a polymer composition made from or containing the polyolefin;(c) precipitating the polymer composition from the supercritical fluid; and(d) pelletizing the precipitant, thereby forming a pelletized resin selected from the group consisting of a pelletized, post-consumer recycled (PCR) resin and a pelletized, post-industrial recycled (PIR) resin.

[0046] In some embodiments, the method for recycling plastic waste include one or more cleaning steps. As previously noted, the mention of one or more method steps does not preclude the presence of additional method steps before or after the combined recited steps or intervening method steps between those steps expressly identified.

[0047] In some embodiments, the plastic waste is made from or containing automobile parts, bleach bottles, food containers, freezer and shopping bags, milk jugs, outdoor furniture, packaging materials, piping, plastic bottles, playground equipment, shampoo bottles, signage and fixtures, toys, and contaminants. In some embodiments, the contaminants are selected from the group consisting of acrylonitrile butadiene styrene (ABS), calcium carbonate, coffee grounds, diapers, dirt, fillers, food stuffs, glass, grass, labels, metals (including aluminum), nylon, other inorganics, other polymers, paper, plant stems, polycarbonates, polyethylene terephthalate (PET), processing additives, property-imparting additives, rubbers, and wood.

[0048] In some embodiments, the supercritical fluid is derived from a chemical compound selected from the group consisting of carbon dioxide, propane, butane, hexane, ethanol, methanol, ethylene, propylene, butylene, dimethyl ether, sulfur hexafluoride, nitrous oxide, halogenated hydrocarbons, and water. In some embodiments, the supercritical fluid is derived from carbon dioxide.

[0049] In some embodiments, the supercritical fluid is further made from or containing a cosolvent selected from the group consisting of alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, esters, ethers, hydrocarbon gases, and ketones. In some embodiments, the supercritical fluid is further made from or containing a cosolvent selected from the group consisting of acetone, dichloromethane ethanol, dimethylformamide, dimethyl sulfoxide, ethyl acetate, heptane, isobutane, isopropanol, methanol, n-hexane, nitrogen, pentane, tetrahydrofuran, and toluene. In some embodiments, the supercritical fluid is further made from or containing a cosolvent, thereby facilitating supercritical fluid extractions at conditions milder than achievable in the absence of the cosolvent. In some embodiments, the cosolvent is a polymer solubilizer.

[0050] In some embodiments, the supercritical fluid is further made from or containing a modifier selected from the group consisting of acetone, acetonitrile, acetyl acetone, methanol, and methyl isobutyl ketone.

[0051] In some embodiments, the supercritical fluid is futher made from or containing chelating agents.

[0052] In some embodiments, the supercritical fluid is further made from or containing surfactants. In some embodiments, the surfactants are selected from the group consisting of cetyltrimethylammonium bromide, olyoxyethylene sorbitan monostearate, polyethylene glycol octylphenyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, and sodium dodecyl sulfate.

[0053] In some embodiments, a supercritical fluid composition is used and made from or containing the supercritical fluid, optionally a cosolvent, optionally a modifier, optionally a chelating agent, or optionally a surfactant, wherein a component of the supercritical fluid composition acts a reactant.

[0054] In some embodiments, the supercritical fluid is made from or containing nonpolar chemical compounds, polar chemical compounds, or combinations thereof.

[0055] In some embodiments, the composition of the supercritical fluid is tailored to the separation or extraction of the components of the plastic waste. In some embodiments, cosolvents and modifiers were added to the supercritical fluid, thereby increasing the solubility of polar chemical compounds. In some embodiments, the composition of the supercritical fluid is selected, thereby providing post-consumer recycled resin for food-packaging applications. In some embodiments, the composition of the supercritical fluid is selected to not be made from orcontaining volatile organic compounds, to limit toxicity, to minimize flammability concerns, to avoid impacting adversely the environment, and to manage reactivity during the extraction.

[0056] In some embodiments, the plastic waste is charged to an extraction vessel, which is subsequently secured for pressure operation. In some embodiments, the chemical compound for preparing the supercritical fluid is added to the extraction vessel. In some embodiments, the chemical compound is further provided with a cosolvent, a modifier, a chelating agent, a surfactant, or a combination thereof. In some embodiments, the temperature and the pressure of the extraction vessel are adjusted, thereby providing a supercritical fluid made from or containing the chemical compound and any optional compounds.

[0057] In some embodiments, the pressure and temperature of the extraction vessel are controlled to provide conditions for extracting the components of the plastic waste. In some embodiments, the components of the plastic waste have differing dissolution characteristics.

[0058] In some embodiments, a first set of components (I) dissolves into the supercritical fluid within a first pressure range (Pl) and a first temperature range (T 1 ), wherein the resin selected from the group consisting of polyethylene and propylene is relatively insoluble at the combination of the first pressure and the first temperature; a second set of components (II), made from or containing the resin, dissolves into the supercritical fluid within a second pressure range (P2) and a second temperature range (T2); and a third set of components (III) is insoluble within the combination of the second pressure range and the second temperature range, wherein P2 > Pl, T2 > Tl, or both.

[0059] In some embodiments, the first set of solubilized components is collected or discharged. In some embodiments, the first set of solubilized components is made from or containing compounds selected from the group consisting of oligomers, low molecular weight species, and plastics. In some embodiments, the low molecular weight species are derived from polymer degradation, food waste, or packaging waste. In some embodiments, the low molecular weight species adversely affect taste or odor, and accordingly, exclude resulting compositions from use in food packaging applications.

[0060] In some embodiments, the temperature and pressure profile extracts and separates the second set of components from other components of the plastic waste, thereby yielding a solubilized post-consumer or post-industrial recycled resin. In some embodiments, the solubilized post-consumer or post-industrial recycled resin is collected in a collection vessel and then thetemperature and the pressure are subsequently reduced, thereby precipitating the post-consumer or post-industrial recycled resin.

[0061] In some embodiments, the insoluble, third set of components is collected or discharged from the extraction vessel. In some embodiments, the third set is made from or containing compounds selected from the group consisting of cellulose fibers, inorganic fillers, and insoluble polymers. In some embodiments, the insoluble polymers are selected from the group consisting of polyamide-imides, polybenzimidazole, polybenzoxazole, polycaprolactone, polyethylene terephthalate, polymethyl methacrylate, polytetrafluoroethylene, polyvinyl chloride, and poly vinylidene fluoride. In some embodiments, the third set of components are separated from the second set of components by mechanical fdtration or centrifugation.

[0062] In some embodiments, the supercritical fluid is recycled to the extraction vessel.

[0063] In some embodiments, the supercritical fluid extraction is completed batchwise or continuously.

[0064] In some embodiments, a first set of components (1) dissolves into the supercritical fluid within a first pressure range (Pl) and a first temperature range (Tl), wherein the components are made from or containing the resin selected from the group consisting of polyethylene and propylene; and a second set of components (II) is insoluble at the combination of the first pressure range and the second temperature range. In some embodiments, the second set of components are separated from the first set of components by mechanical filtration or centrifugation. In some embodiments, the pressure and the temperature of the supercritical fluid are subsequently reduced, thereby precipitating the post-consumer or post-industrial recycled resin. In some embodiments, other components remain solubilized at the reduced pressure and temperature and are subsequently collected or discharged.

[0065] In some embodiments, the present disclosure provides a post-consumer recycled resin prepared from a post-consumer recyclate, wherein the resin is selected from the group consisting of polyethylene and polypropylene. In some embodiments, the polyethylene is a high- density polyethylene.

[0066] In some embodiments, the present disclosure provides a post-industrial recycled resin prepared from a post-industrial recyclate, wherein the resin is selected from the group consisting of polyethylene and polypropylene.

[0067] In some embodiments, the present disclosure provides a polymer composition made from or containing resin selected from the group consisting of a post-consumer recycled resin and a post-industrial recycled resin. In some embodiments, the polymer composition is made from or containing:(a) from 5 % by weight to 95 % by weight, based upon the total weight of the polymer composition, of a resin selected from the group consisting of a post-consumer recycled resin and a post-industrial recycled resin; and(b) from 5 % by weight to 95 % by weight, based upon the total weight of the polymer composition, of a virgin polymer.

[0068] In some embodiments, the resin is selected from the group consisting of HDPE PCR and PP PCR. In some embodiments, the resin is the base resin of the polymer composition. In some embodiments, the resin is a complementary resin. In some embodiments, the resin is a component in an additive composition or a filler, for use with a virgin or other PCR resin. In some embodiments, the resin is used as a filler in amount up to 50 % by weight, alternatively from 0.5 % by weight to 30 % by weight, alternatively from 1.0 % by weight to 20% by weight, based upon the total weight of the polymer composition.

[0069] In some embodiments, the resin bears the International Code Council (ICC) Certification.

[0070] In some embodiments, the polymer composition is further made from or containing an additive composition. In some embodiments, the additive composition imparts properties such as thermal stability, light and ultraviolet protection, and color. In some embodiments, the additive composition is present in an amount from 0.05 % by weight to 10 % by weight, alternatively from 0.1 % by weight to 8 % by weight, based upon the total weight of the polymer composition.

[0071] In some embodiments, the present disclosure provides an article of manufacture made from or containing a resin selected from the group consisting of post-consumer recycled resins and post-industrial recycled resins. In some embodiments, the article of manufacture is selected from the group consisting of blow-molded articles, films, flexibles, injection-molded articles, packaging, and piping. In some embodiments, the article of manufacture is useful in noncosmetic-intensive, post consumer recycled resin applications, including agricultural film and trash bags.

Claims

CLAIMSWhat is claimed is:

1. A method for recycling plastic waste comprising the step of: extracting and separating (i) post-consumer recycled (PCR) resin components, (ii) postindustrial recycled (PIR) resin components, or both from plastic waste with a supercritical fluid, wherein the plastic waste is selected from the group consisting of post-consumer recyclate and post-industrial recyclate.

2. The method for recycling plastic waste of Claim 1, comprising the steps of:(a) collecting the plastic waste from residential, commercial, and industrial sites, wherein the plastic waste is selected from the group consisting of post-consumer recyclate and post-industrial recyclate, and made from or containing a polyolefin and a contaminant;(b) extracting and separating the contaminant from the polyolefin with a supercritical fluid, thereby yielding a polymer composition made from or containing the polyolefin;(c) precipitating the polymer composition from the supercritical fluid; and(d) pelletizing the precipitant, thereby forming a pelletized resin selected from the group consisting of a pelletized, post-consumer recycled (PCR) resin and a pelletized, post-industrial recycled (PIR) resin.

3. The method for recycling plastic waste of Claim 1, comprising the steps of:(a) collecting the plastic waste from residential, commercial, and industrial sites, wherein the plastic waste is selected from the group consisting of post-consumer recyclate and post-industrial recyclate, and made from or containing a polyolefin and a contaminant;(a.i) sorting the plastic waste;(a.ii) cleaning the plastic waste;(a.iii) grinding the plastic waste, thereby yielding a powder made from or containing the polyolefin and the contaminant;(b) extracting and separating the contaminant from the polyolefin with a supercritical fluid through supercritical fluid extraction of the powder, thereby yielding a polymer composition made from or containing the polyolefin;(c) precipitating the polymer composition from the supercritical fluid; and(d) pelletizing the precipitant, thereby forming a pelletized resin selected from the group consisting of a pelletized, post-consumer recycled (PCR) resin and a pelletized, post-industrial recycled (PIR) resin.

4. The method for recycling plastic waste of Claim 1, wherein the plastic waste comprises automobile parts, bleach bottles, food containers, freezer and shopping bags, milk jugs, outdoor furniture, packaging materials, piping, plastic bottles, playground equipment, shampoo bottles, signage and fixtures, toys, and contaminants.

5. The method for recycling plastic waste of Claim 4, wherein the contaminants are selected from the group consisting of acrylonitrile butadiene styrene (ABS), calcium carbonate, coffee grounds, diapers, dirt, fillers, food stuffs, glass, grass, labels, metals (including aluminum), nylon, other inorganics, other polymers, paper, plant stems, polycarbonates, polyethylene terephthalate (PET), processing additives, property-imparting additives, rubbers, and wood.

6. The method for recycling plastic waste of Claim 1, wherein the supercritical fluid is derived from a chemical compound selected from the group consisting of carbon dioxide, propane, butane, hexane, ethanol, methanol, ethylene, propylene, butylene, dimethyl ether, sulfur hexafluoride, nitrous oxide, halogenated hydrocarbons, and water.

7. The method for recycling plastic waste of Claim 6, wherein the supercritical fluid further comprises a cosolvent selected from the group consisting of alcohols, aliphatic hydrocarbons, aromatic hydrocarbons, esters, ethers, hydrocarbon gases, and ketones.

8. The method for recycling plastic waste of Claim 6, wherein the supercritical fluid further comprises a modifier selected from the group consisting of acetone, acetonitrile, acetyl acetone, methanol, and methyl isobutyl ketone.

9. The method for recycling plastic waste of Claim 6, wherein the supercritical fluid further comprises a chelating agent.

10. The method for recycling plastic waste of Claim 6, wherein the supercritical fluid further comprises a surfactant selected from the group consisting of cetyltrimethylammonium bromide, oly oxy ethylene sorbitan monostearate, polyethylene glycol octylphenyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monooleate, and sodium dodecyl sulfate.

11. A post-consumer recycled resin comprising a resin selected from the group consisting of polyethylene and polypropylene, prepared by the method for recycling plastic waste according to Claim 1.

12. An article of manufacture comprising the post-consumer recycled resin of Claim 11.