Modified PET-Degrading Polypeptide for Closed-Loop Monomer Recycling

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Solution Overview

Problem

Current methods for PET degradation and recycling face challenges such as quality deterioration, carbon neutrality issues, and environmental impact, with no existing technology being considered perfect.

Innovation Solution

A modified polypeptide with PET degradation activity is developed, along with methods for synthesizing and recycling PET using mono(2-hydroxymethyl) terephthalate (MHET), terephthalic acid (TPA), and ethylene glycol (EG), enabling enzymatic degradation of PET into high-value degradation products.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If mechanical recycling is used for PET waste, then recycling efficiency is improved, but quality deterioration occurs due to downcycling

Engineering Contradiction:

Improverecycling efficiencyVSAvoidproduct quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent replaces mechanical recycling methods with an enzymatic system using modified polypeptides (PETase variants) to degrade PET. This biochemical approach substitutes physical mechanical processes with enzyme-catalyzed chemical reactions, enabling high-quality monomer recovery without the quality deterioration associated with mechanical downcycling.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs engineered polypeptides with modified amino acid sequences and altered catalytic parameters. By changing the biochemical parameters of the degrading agent (enzyme structure, active site configuration, stability characteristics), the system achieves complete PET degradation to high-purity monomers, resolving the quality loss issue while maintaining high recycling efficiency.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If chemical recycling methods are applied, then complete degradation is achieved, but environmental harm increases due to eutrophication and carbon neutrality issues

Engineering Contradiction:

Improvedegradation completenessVSAvoidenvironmental impact

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces harsh chemical recycling processes with a biochemical enzymatic system. Instead of using strong chemicals that cause eutrophication and carbon emissions, the system employs modified polypeptides that catalyze PET degradation under mild conditions, producing the same complete degradation effect without the harmful environmental byproducts.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The enzymatic system operates under mild physiological conditions without requiring additional chemicals or extreme energy inputs. The modified polypeptides self-catalyze the degradation process, converting PET directly into monomers through bio-friendly pathways, thereby achieving complete degradation while minimizing environmental harm and aligning with carbon neutrality goals.

Inventive Principle:

Principle #25Self-service

3Productivity

If existing recycling technologies are used, then waste plastic processing is achieved, but resource depletion continues due to imperfect recycling

Engineering Contradiction:

Improvewaste processing capabilityVSAvoidresource depletion

Core Design Contradiction:

ProductivityVSLoss of substance

Solution Approach 1:

The patent implements a complete recovery system where PET waste is fully degraded into its original monomers (terephthalic acid and ethylene glycol) using modified polypeptides. These recovered monomers can be directly reused for synthesizing new PET, achieving closed-loop recycling that eliminates resource depletion while maintaining high waste processing capability.

Inventive Principle:

Principle #34Discarding and recovering

Solution Approach 2:

The enzymatic degradation system enables continuous recycling operations where PET waste is continuously converted back into usable monomers without quality loss. This continuous cycle of degradation and re-synthesis ensures that resources are perpetually recovered and reused, preventing resource depletion while maintaining efficient waste processing.

Inventive Principle:

Principle #20Continuity of useful action

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 modified polypeptide degrades PET in an environmentally friendly manner, producing MHET, TPA, and EG that can be recycled for polyester synthesis, addressing the inefficiencies of existing recycling methods.

Implementation Method 1

a modified polypeptide having a PET degradation activity

Methodology Applied

Scientific EffectEnzymatic degradation: Enzyme

Implementation Method 2

degradation products with high commercial value, such as mono(2-hydroxymethyl) terephthalate (MHET), terephthalic acid (TPA), and/or ethylene glycol (EG) are produced

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP4715050A1Modified polypeptide having pet degradation activity

Publication Date: 2026.03.25 ZYEN CO LTD

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AI summary

Provided are a modified polypeptide having a PET degradation activity and use thereof.