Solvolysis Coproduct Recycling for Low-Value Plastic Waste Streams

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Solution Overview

Problem

Conventional recycling technologies are unable to economically process low-value waste streams, leading to additional waste disposal issues and environmental impact, while some processes generate further waste streams that are not economically recoverable.

Innovation Solution

A chemical recycling method involving solvolysis and subsequent processing in facilities such as partial oxidation gasification, pyrolysis, solidification, cracker, and energy generation to convert mixed plastic waste into valuable products, minimizing waste production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional recycling technologies are used, then processing costs are reduced, but the ability to process low-value waste streams is insufficient

Engineering Contradiction:

Improveprocessing costVSAvoidability to process low-value waste streams

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by using solvolysis to chemically break down PET polymers into monomers under controlled conditions (temperature, pressure, catalyst), transforming the chemical structure and properties of the waste material to enable recovery of valuable components from low-value streams

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces mechanical sorting and processing methods with chemical recycling processes (solvolysis, gasification, pyrolysis), substituting chemical reactions for mechanical operations to achieve more effective processing of complex waste streams

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Device complexity

If conventional recycling processes are used, then production simplicity is maintained, but additional waste streams are generated that are not economically recoverable

Engineering Contradiction:

Improveprocess simplicityVSAvoideconomically recoverable waste streams

Core Design Contradiction:

Device complexityVSLoss of substance

Solution Approach 1:

The patent converts harmful waste streams into valuable products by using gasification and pyrolysis processes that transform non-recoverable residues into syngas, fuel oils, and other energy carriers, turning environmental burdens into economic assets

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent creates a multi-functional integrated system where the same facility performs multiple functions: solvolysis for PET depolymerization, gasification for carbon-containing waste conversion, pyrolysis for plastic decomposition, and energy generation, allowing one facility to handle diverse waste streams and produce multiple valuable outputs

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Loss of substance

If chemical recycling methods are used, then waste stream recovery is improved, but process complexity increases

Engineering Contradiction:

Improvewaste stream recoveryVSAvoidprocess complexity

Core Design Contradiction:

Loss of substanceVSDevice complexity

Solution Approach 1:

The patent merges multiple chemical recycling processes (solvolysis, gasification, pyrolysis) and energy generation into a single integrated facility, combining separate functions into one cohesive system that shares infrastructure and optimizes resource utilization

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method effectively processes a wide range of plastics, reducing waste streams and producing commercially valuable end products, enhancing efficiency and minimizing environmental impact.

Implementation Method 1

subjecting at least a portion of the PET-enriched stream to solvolysis in a solvolysis facility to form a principal glycol product, a principal terephthalyl product

Methodology Applied

Scientific EffectSolvolysis:

Implementation Method 2

introducing a polyolefin-containing coproduct stream from a solvolysis facility into at least one of the following: (i) a partial oxidation (POX) gasification facility

Methodology Applied

Scientific EffectPartial oxidation: Oxidation

Implementation Method 3

introducing a polyolefin-containing coproduct stream from a solvolysis facility into at least one of the following: (ii) a pyrolysis facility

Methodology Applied

Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentUS12516250B2Chemical recycling of solvolysis coproduct streams

Publication Date: 2026.01.06 EASTMAN CHEM CO

AI summary

Chemical recycling facilities for processing mixed plastic waste are provided herein. Such facilities have the capability of processing mixed plastic waste streams and utilize a variety of recycling facilities, such as, for example, solvolysis facility, a pyrolysis facility, a cracker facility, a partial oxidation gasification facility, an energy generation/energy production facility, and a solidification facility. Streams from one or more of these individual facilities may be used as feed to one or more of the other facilities, thereby maximizing recovery of valuable chemical components and minimizing unusable waste streams.