PHA Production from PET Waste via Bacterial Fermentation

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The recycling of polyethylene terephthalate (PET) is inefficient due to high costs associated with sorting and the low value of downstream products, with less than 25% of PET bottles being recycled globally, leading to significant waste accumulation in landfills.

Innovation Solution

A method for producing biodegradable polyhydroxyalkanoate (PHA) using bacterial strains such as Pseudomonas putida and Pseudomonas frederiksbergensis, which accumulate PHA from terephthalic acid derived from PET pyrolysis, allowing for the conversion of PET waste into a high-value, biodegradable polymer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If PET is recycled through mechanical grinding or reprocessing, then waste PET can be utilized, but the sorting cost is high and the downstream product has low value

Engineering Contradiction:

Improverecycling process feasibilityVSAvoidrecycling efficiency

Core Design Contradiction:

Ease of manufactureVSProductivity

Solution Approach 1:

The patent changes the chemical parameter of PET from its original polymer form to monomeric components (terephthalic acid and ethylene glycol) through pyrolysis, enabling complete degradation and conversion to high-value PHA product, thereby resolving the low value issue of downstream products

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful waste PET into beneficial PHA polymer through pyrolysis and bacterial fermentation processes, transforming the waste problem into a valuable biodegradable polymer product with high economic value

Inventive Principle:

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

2Loss of substance

If PET is recycled, then waste material is reduced, but the cost of sorting and processing is high

Engineering Contradiction:

Improvewaste reductionVSAvoidprocessing cost

Core Design Contradiction:

Loss of substanceVSEase of manufacture

Solution Approach 1:

The patent converts waste PET into valuable PHA polymer through pyrolysis and fermentation, creating a high-value product that justifies the processing cost and eliminates the need for expensive sorting operations

Inventive Principle:

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

Solution Approach 2:

The patent changes the physical and chemical state of PET from solid polymer to monomeric components and finally to PHA polymer, enabling complete material conversion and eliminating waste while reducing processing costs

Inventive Principle:

Principle #35Parameter changes

3Reliability

If conventional PHA production substrates are used, then PHA can be produced, but the substrate cost is high and not economically viable

Engineering Contradiction:

ImprovePHA production feasibilityVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent changes the substrate from expensive conventional sources to low-cost PET waste derivatives, specifically using terephthalic acid and ethylene glycol from pyrolysis, thereby dramatically reducing production cost while maintaining PHA production feasibility

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts low-value PET waste into valuable PHA polymer through bacterial fermentation, creating a economically viable process that produces high-value biodegradable polymer from inexpensive feedstock

Inventive Principle:

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

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

This method provides a cost-effective and clean process for producing PHA, utilizing inexpensive PET waste as a feedstock, resulting in a polymer with desirable properties suitable for various applications, including biomedical and packaging uses, while addressing the waste management issues associated with PET recycling.

Implementation Method 1

culturing in a culture medium comprising terephthalic acid and/or a salt thereof and/or an ester thereof one or more bacterial strains which are capable of accumulating PHA from terephthalic acid

Methodology Applied

Scientific EffectFermentation: Fermentation

Implementation Method 2

PET can be degraded by pyrolysis to its monomeric components, terephthalic acid and ethylene glycol. pyrolysis (thermal treatment in the absence of air) of waste PET

Methodology Applied

Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentEP2276841B1Method for producing polyhydroxyalkanoate

Publication Date: 2011.09.07 UNIV COLLEGE DUBLIN NAT UNIV OF IRELAND DUBLIN

Figure 1(A)~1(C)
Figure 2
Figure 3

AI summary

A method for producing polyhydroxyalkanoate (PHA), comprising (i) culturing in a culture medium comprising terephthalic acid and/or a salt thereof and/or an ester thereof one or more bacterial strains which are capable of accumulating PHA from terephthalic acid or a salt or ester thereof and which are selected from Pseudomonas putida strain GO 16 having the accession number NCIMB 41538, Pseudomonas putida strain GO 19 having the accession number NCIMB 41537, and Pseudomonas frederiksbergensis strain GO23 having the accession number NCIMB 41539; and (ii) recovering the PHA produced from the culture medium. The invention also provides Pseudomonas putida strain GO16 having the accession number NCIMB 41538; Pseudomonas putida strain GO 19 having the accession number NCIMB 41537; and Pseudomonas frederiksbergensis strain GO23 having the accession number NCIMB 41539.