US-12617921-B2 - Chemical recycling of reclaimer flake reject

Abstract

A method of recycling plastic waste by feeding a quantity of PET and PVC-containing reclaimer flake reject separated from the plastic waste to a chemical recycling facility; and depolymerizing in said chemical recycling facility at least a portion of said PET- and PVC-containing reclaimer flake reject which further comprises feeding at least a portion of the flake reject into at least one density separation stage before depolymerizing, in which a PET-enriched stream and a polyolefins-enriched stream are produced from a waste plastic stream comprising the flake reject; wherein the flake reject comprises at least 1 weight percent of PVC on a dry basis, and wherein the flake reject comprises at least 0.1 weight percent and/or not more than 20 weight percent polyolefins on a dry basis, wherein the flake reject is fed directly into a solvolysis facility within the chemical recycling facility and the solvolysis facility is a methanolysis facility.

Inventors

• Bruce Roger DeBruin
• Michael Paul Ekart
• Anne-Martine Sherbeck Jackson
• Nathan Mitchell West
• Zhufang Liu

Assignees

• EASTMAN CHEMICAL COMPANY

Dates

Publication Date

20260505

Application Date

20210413

Claims (9)

1. 1 . A method of recycling a plastic waste comprising: (a) feeding a quantity of PET and PVC-containing reclaimer flake reject separated from said plastic waste to a chemical recycling facility; and (b) depolymerizing in said chemical recycling facility at least a portion of said PET- and PVC-containing reclaimer flake reject further comprising feeding at least a portion of said flake reject into at least one density separation stage before said depolymerizing (b), in which a PET-enriched stream and a polyolefins-enriched stream are produced from a waste plastic stream comprising said flake reject; wherein said flake reject comprises at least 1 weight percent of PVC on a dry basis, and wherein said flake reject comprises at least 0.1 weight percent and/or not more than 20 weight percent polyolefins on a dry basis, wherein said flake reject is fed directly into a solvolysis facility within said chemical recycling facility and the solvolysis facility is a methanolysis facility.
2. 2 . The method of claim 1 , wherein said flake reject comprises at least 0.1 weight percent PET on a dry basis.
3. 3 . The method of claim 1 , further comprising feeding at least a portion of said PET-enriched stream into a solvolysis facility.
4. 4 . The method of claim 1 , further comprising feeding at least a portion of said polyolefins-enriched stream into a partial oxidation (POX) gasifier.
5. 5 . The method of claim 1 , further comprising feeding at least a portion of said polyolefins-enriched stream into a pyrolysis facility.
6. 6 . The method of claim 1 , further comprising feeding at least a portion of said polyolefins-enriched stream into an energy recovery facility.
7. 7 . The method of claim 1 , further comprising feeding at least a portion of said flake reject into a mechanical dewatering apparatus before said depolymerizing (b).
8. 8 . The method of claim 7 , wherein said flake reject is fed into a thermal dryer after said mechanical dewatering apparatus.
9. 9 . The method of claim 1 , wherein a caustic component or caustic solution is introduced along with said flake reject to a dissolver and/or a solvolysis reactor within said solvolysis facility.

Description

CROSS-REFERENCE TO RELATED APPLICATION(S) This application is a national stage filing under 35 USC § 371 of International Application Number PCT/US2021/026981, filed on Apr. 13, 2021 which claims the benefit of the filing date to U.S. Provisional Application No. 63/008,920, filed on Apr. 13, 2020, the entire disclosures of which are incorporated by reference herein. BACKGROUND Waste materials, especially non-biodegradable waste materials, can negatively impact the environment when disposed of in landfills after a single use. Thus, from an environmental standpoint, it is desirable to recycle as much waste material as possible. However, there still exist streams of low value waste that are nearly impossible or economically unfeasible to recycle with conventional recycling technologies. In addition, some conventional recycling processes produce waste streams that are themselves not economically feasible to recover or recycle, resulting in additional waste streams that must be disposed of or otherwise handled. For example, plastic reclaimer facilities can produce significant amounts of waste plastics that are undesirable or unusable by consumers and mechanical recycling facilities. In particular, plastic reclaimer facilities can produce quantities of plastic flake reject materials that are undesirable or unusable to mechanical recycling facilities due to the PVC content, but may contain some amount of otherwise desirable or usable PET and/or other plastics. However, flake reject materials are typically disposed of in landfills and/or incinerators. Thus, a need exists for a large-scale facility capable of chemically recycling a variety of plastic-containing waste materials recovered from such sources, particularly otherwise undesirable or unusable flake reject materials from a plastic reclaimer facility, in an economically viable manner. SUMMARY In one aspect, the present technology concerns a method of recycling a plastic waste. Generally, the method comprises: (a) feeding a quantity of PET and PVC-containing reclaimer flake reject separated from the plastic waste to a chemical recycling facility; and (b) depolymerizing in the chemical recycling facility at least a portion of the PET and PVC-containing reclaimer flake reject. In one aspect, the present technology concerns the use of PET and PVC-containing reclaimer flake reject as a feedstock to a chemical recycling facility. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block flow diagram illustrating the main steps of a process and facility for chemically recycling waste plastic according to embodiments of the present technology; FIG. 2 is a block flow diagram illustrating a separation process and zone for separating mixed plastic waste according to embodiments of the present technology; FIG. 3 is a block flow diagram illustrating the main steps of a process and facility for PET solvolysis according to embodiments of the present technology; FIG. 4 is a block flow diagram illustrating typical rPET products and co-products derived from a PET reclaimer facility; FIG. 5 is a block flow diagram illustrating the main steps of a PET reclaimer process, and the resulting products and co-products produced therefrom; FIG. 6 is a block flow diagram illustrating an exemplary liquification zone of the chemical recycling facility shown in FIG. 1 according to embodiments of the present technology; FIG. 7 is a block flow diagram illustrating the main steps of a pyrolysis process and facility for converting waste plastic into a pyrolyzed product streams according to embodiments of the present technology; FIG. 8A is a block flow diagram illustrating the main steps of an integrated pyrolysis process and facility and a cracking process and facility according to embodiments of the present technology; FIG. 8B is a schematic diagram of a cracking furnace according to embodiments of the present technology; FIG. 9 is a schematic diagram of a POx reactor according to embodiments of the present technology; and FIG. 10 is a schematic diagram illustrating various definitions of the term “separation efficiency” as used herein. DETAILED DESCRIPTION We have discovered new methods and systems for using one or more PET-containing materials from various sources as a feedstock to a chemical recycling facility, and in particular a solvolysis facility. More particularly, we have discovered that PET-containing materials used as feedstock for chemical recycling or solvolysis may include flake reject materials derived from plastic reclaimer facilities. While these flake reject materials are generally considered undesirable or unusable by mechanical recycling facilities due to their PVC content, they can contain some amount of recoverable and useful plastics, such as PET-plastics. The methods and systems described herein are capable of using such PET and PVC-containing reclaimer flake reject materials as a feedstock source in chemical recycling facilities and processes. When a numerical sequence is in