Polyurethane Fuel Pellets with Controlled Chlorine and Density

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Solution Overview

Problem

The challenge lies in effectively utilizing polyurethane foam from discarded electrical appliances as fuel due to high residual chlorine concentrations, low bulk specific gravity leading to high transportation costs, and difficulties in handling and dust prevention during compression molding.

Innovation Solution

The development of a fuel pellet with a bulk specific gravity of 0.45 to 0.55 and residual chlorine concentration of 0.3 wt. percent or less, formed by compression molding powdered polyurethane, using a cylindrical shape with a specific length-to-diameter ratio, and processed under negative pressure conditions to enhance degassing efficiency without forced heating or dechlorination agents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If chlorofluorocarbon-expanded urethane foam is crushed into powdered state, then it can be processed as fuel, but the residual chlorine concentration remains high (1.0 wt. percent or more) making it unsuitable for ordinary fuel use

Engineering Contradiction:
Improveprocessability as fuelVSAvoidresidual chlorine concentration
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The patent changes the physical parameters of the polyurethane foam by controlling particle size distribution (mixing fine particles of 0.1-1mm with coarse particles of 1-10mm) and bulk density (0.45-0.55 g/cm³) to enable direct combustion without chemical dechlorination, thus reducing residual chlorine to acceptable levels while maintaining fuel usability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite fuel structure by mixing polyurethane foam particles of different sizes and densities, forming a heterogeneous material that optimizes both combustion characteristics and chlorine release behavior, enabling effective fuel utilization

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If urethane foam is light weight with small bulk specific gravity, then it is easy to handle, but it becomes difficult to transport due to high transportation costs

Engineering Contradiction:
Improvehandling easeVSAvoidtransportation cost
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent optimizes the bulk specific gravity parameter to 0.45-0.55 g/cm³ by controlling particle size distribution and packing density, achieving a balance between handling ease and transportation efficiency, reducing transportation costs while maintaining operational convenience

Inventive Principle:
Principle #35Parameter changes

3Loss of energy

If polyurethane foam is compressed into pellets, then transportation efficiency improves, but dust generation and handling difficulties increase

Engineering Contradiction:
Improvetransportation efficiencyVSAvoiddust generation
Core Design Contradiction:
Loss of energyVSObject-generated harmful factors

Solution Approach 1:

The patent applies different particle size qualities to different functional requirements: fine particles (0.1-1mm) fill gaps to reduce dust, while coarse particles (1-10mm) maintain structural integrity during handling, creating a locally optimized mixed-grain fuel pellet

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent creates a composite particle structure combining different size classes of polyurethane foam particles, forming a multi-scale material that reduces dust generation through interlocking fine particles while maintaining bulk handling efficiency

Inventive Principle:
Principle #40Composite materials

4Device complexity

If ordinary compression molding is used on polyurethane foam, then the process is simple, but the residual chlorine concentration remains high and fuel standards are not met

Engineering Contradiction:
Improveprocessing simplicityVSAvoidresidual chlorine concentration
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the compression parameters (pressure, temperature, duration) and particle configuration (size distribution, bulk density) to optimize chlorine release during compression, achieving fuel compliance through physical parameter optimization rather than complex chemical treatment processes

Inventive Principle:
Principle #35Parameter changes

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 solution allows the polyurethane fuel pellets to be used in ordinary incinerators and boilers, reducing transportation costs, preventing dust generation, and improving handling while maintaining safety and efficiency in the manufacturing process.

Implementation Method 1

formed by compression molding powdered polyurethane that is obtained by crushing urethane foam, with the bulk specific gravity set to 0.45 to 0.55

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 2

processed under negative pressure conditions to enhance degassing efficiency

Methodology Applied
Scientific EffectVacuum degassing: Vacuum

Data Source

PatentEP2474600B1Fuel pellet, fuel pellet production method, and fuel pellet production device
Publication Date: 2015.04.15 PANASONIC HOLDINGS CORP
  • EP2474600B1 patent drawingFigure 1
  • EP2474600B1 patent drawingFigure 2
  • EP2474600B1 patent drawingFigure 3

AI summary

The fuel pellet of the present invention is formed by compression molding, powdered polyurethane that is obtained by crushing urethane foam, with the bulk specific gravity being 0.45 to 0.55, and the residual chlorine concentration being 0.3 wt. percent or less.