Microwave Pyrolysis of Polymer Waste for Reduced Char

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Solution Overview

Problem

Current recycling methods for polymeric waste materials, particularly rubber and plastics, are inefficient, energy-intensive, and costly, with existing pyrolysis methods producing unwanted carbonaceous residues and low yields of marketable recycled materials.

Innovation Solution

A fast thermal pyrolysis method using microwave radiation to decompose polymer materials and waste materials, particularly rubber tires, in a sequential process with differing target temperatures for various material components, allowing for efficient recovery of reusable materials and energy as combustible biogas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional pyrolysis methods are used to decompose polymer waste materials, then thermal decomposition occurs, but carbonaceous residues are produced and yields of marketable recycled materials are low

Engineering Contradiction:

Improvecarbonaceous residuesVSAvoidyields of marketable recycled materials

Core Design Contradiction:

Loss of substanceVSProductivity

Solution Approach 1:

The patent applies parameter changes by optimizing pyrolysis temperature, heating rate, and residence time to maximize the production of liquid and gas products while minimizing carbonaceous residue formation. By controlling these parameters, the process shifts product distribution toward more valuable recyclable materials.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces conventional slow pyrolysis with fast pyrolysis technology, fundamentally changing the decomposition mechanism through rapid heating and short residence times. This substitution transforms the product yield profile, significantly reducing char formation and increasing liquid bio-oil and syngas production.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Ease of manufacture

If grinding process is used to create crumb rubber, then rubber waste is processed, but power consumption increases and wear and tear intensifies

Engineering Contradiction:

Improverubber processingVSAvoidpower consumption

Core Design Contradiction:

Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent replaces mechanical grinding with thermal pyrolysis, substituting a mechanical size-reduction process with a thermal decomposition process. This eliminates the need for high-power grinding equipment and reduces mechanical wear, while converting the rubber into valuable pyrolysis products.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes phase transitions during pyrolysis, where solid rubber waste is converted into liquid bio-oil and gaseous syngas through controlled thermal decomposition. This phase change approach avoids mechanical processing entirely and directly transforms the material into recyclable products.

Inventive Principle:

Principle #36Phase transitions

3Use of energy by moving object

If cryogenic techniques are used to reduce energy consumption for grinding, then processing energy decreases, but cryogenic liquid costs and process time increase

Engineering Contradiction:

Improvegrinding energy consumptionVSAvoidcooling process time

Core Design Contradiction:

Use of energy by moving objectVSLoss of time

Solution Approach 1:

The patent replaces cryogenic mechanical grinding with thermal pyrolysis, eliminating the need for cryogenic cooling and associated time losses. The thermal process directly decomposes the rubber at elevated temperatures, achieving material transformation without the time-consuming cooling and heating cycles required by cryogenic methods.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Strength

If vulcanization is used to convert rubber into durable materials, then material durability improves, but harmful emissions are released

Engineering Contradiction:

Improvematerial durabilityVSAvoidharmful emissions

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful emissions from conventional vulcanization and incineration into beneficial products through controlled pyrolysis. The organic components are transformed into liquid bio-oil and gaseous syngas that can be used as fuels or chemical feedstocks, while the sulfur and inorganic materials are concentrated in the char for potential recovery or safe disposal.

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

The method achieves efficient thermal decomposition of polymer waste materials with reduced carbonaceous residues, high yields of recyclable materials, and cost-effective energy recovery, promoting sustainable waste management and circular economies.

Implementation Method 1

heated to a decomposition temperature of the waste material by microwave radiation

Methodology Applied

Scientific EffectMicrowave radiation: Microwave Radiation

Implementation Method 2

pyrolysis method for thermal decomposition of polymer materials and polymer waste materials

Methodology Applied

Scientific EffectThermal decomposition: Pyrolysis

Data Source

PatentUS12325638B2Pyrolysis of polymer waste materials

Publication Date: 2025.06.10 MICROWAVE SOLUTIONS GMBH

AI summary

A pyrolysis method and a pyrolysis reactor for thermal decomposition of polymer waste materials, particularly rubber and plastics waste materials, using a fast pyrolysis process, are disclosed. The waste material is delivered to a pyrolytic chamber, and is heated to a decomposition temperature of the waste material by microwave radiation.