Polyurethane Waste Recycling via Pyrolysis and Electrolysis

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Solution Overview

Problem

Current methods for producing isocyanates and polyurethanes rely heavily on fossil fuels, leading to high carbon footprints and inefficient recycling of polyurethane material waste.

Innovation Solution

A method involving the recycling of polyurethane material waste through pyrolysis, followed by electrolysis of carbon dioxide to produce carbon monoxide, which is then converted into isocyanates and ultimately new polyurethane materials, while utilizing renewable energy and reducing fossil fuel dependency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If polyurethane waste is incinerated with air to produce energy, then energy recovery is achieved, but carbon dioxide emissions increase and carbon feedstock is lost

Engineering Contradiction:

Improveenergy recoveryVSAvoidcarbon dioxide emissions

Core Design Contradiction:

Use of energy by moving objectVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful carbon dioxide emissions from incineration into a beneficial resource by capturing CO2 and using it as feedstock for electrochemical conversion to produce isocyanates and polyurethanes, transforming a waste product into valuable chemical building blocks

Inventive Principle:

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

Solution Approach 2:

Instead of completely discarding polyurethane waste through conventional incineration, the patent recovers carbon feedstock in the form of CO2 and CO, which are then converted into new polyurethane materials, achieving circular economy principles

Inventive Principle:

Principle #34Discarding and recovering

2Loss of substance

If polyurethane material waste is recycled through conventional methods, then material recovery is achieved, but the process is inefficient and does not close the value chain

Engineering Contradiction:

Improvematerial recoveryVSAvoidrecycling efficiency

Core Design Contradiction:

Loss of substanceVSProductivity

Solution Approach 1:

The patent replaces conventional mechanical and thermal recycling methods with electrochemical conversion processes, using electricity to directly convert CO2 into isocyanates, which significantly improves recycling efficiency and enables true value chain closure

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the chemical parameters of the waste material by converting CO2 into different chemical forms (CO, isocyanates) through electrochemical reactions, transforming low-value waste into high-value chemical feedstock

Inventive Principle:

Principle #35Parameter changes

3Productivity

If fossil fuels are used for producing isocyanates and polyurethanes, then production volume is maintained, but carbon footprint increases and sustainability decreases

Engineering Contradiction:

Improveproduction volumeVSAvoidcarbon footprint

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent enables the polyurethane industry to serve itself by using CO2 from its own waste streams as feedstock for producing new polyurethanes, creating a self-sustaining circular system that reduces external fossil fuel dependency

Inventive Principle:

Principle #25Self-service

Solution Approach 2:

The patent makes CO2 serve multiple functions: it acts as both a waste product from incineration and as a valuable chemical feedstock for producing isocyanates and polyurethanes, demonstrating multi-functionality of the same material

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 effectively closes the value chain for polyurethane production, reduces the reliance on fossil fuels, and decreases carbon emissions by utilizing recycled materials and renewable energy sources.

Implementation Method 1

starting from polyurethane material waste, carbon dioxide and hydrocarbons and possibly carbon monoxide and hydrogen are generated by pyrolysis

Methodology Applied

Scientific EffectPyrolysis: Pyrolysis

Implementation Method 2

the carbon dioxide is converted by electrolysis to carbon monoxide and possibly hydrogen

Methodology Applied

Scientific EffectElectrolysis: Electrolysis

Implementation Method 3

use of oxygen for incinerating materials containing polyurethane to obtain carbon dioxide

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS12275689B2Method for the recycling of polyurethane material waste for producing chemical feedstock for the production of isocyanates and polyurethanes

Publication Date: 2025.04.15 COVESTRO INTELLECTUAL PROPERTY GMBH & CO KG

AI summary

The invention relates to a method for recycling polyurethane material waste (18a) for producing chemical feedstock for the production of isocyanates (10a) and then polyurethanes (16a), in which method, proceeding from polyurethane material waste (18a), carbon dioxide (1a) and hydrocarbons (1c) are generated by pyrolysis (1), the carbon dioxide (1a; 4a) is converted by electrolysis (5) into carbon monoxide (7b) and hydrogen (7a), as appropriate, the carbon monoxide (7b; 7c) obtained is converted via phosgene to isocyanate (10a) and the isocyanate (10a) can be further processed into new polyurethane material (16a).