Stabilized Lignin via Hydrothermal Carbonization

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Solution Overview

Problem

Existing methods for producing lignin from biomass fractionation processes result in thermoplastic lignin that is not temperature-stable, limiting its applications, and previous stabilization methods are costly or unclear in controlling particle size distribution during hydrothermal carbonization.

Innovation Solution

Adjusting the H+ ion concentration in the lignin-containing liquid before and during hydrothermal carbonization to control the grain size distribution of the resulting carbonized lignin, allowing for separation and purification of stabilized lignin with defined properties.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If lignin is obtained from biomass fractionation processes, then lignin is produced as a byproduct, but the lignin is thermoplastic and not temperature-stable, limiting its applications

Engineering Contradiction:
Improvethermal stabilityVSAvoidapplication range
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent applies hydrothermal carbonization by changing temperature (150-280°C), pressure (autogenous), and pH (3-11) parameters to transform thermoplastic lignin into thermally stable carbonized lignin. This parameter change resolves the contradiction by achieving both thermal stability and expanded application versatility through controlled chemical transformation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition during hydrothermal carbonization where lignin transforms from dissolved/colloidal state to solid carbonized particles. This phase transition fundamentally changes the thermal properties from thermoplastic to thermally stable, resolving the contradiction between thermal stability and application versatility.

Inventive Principle:
Principle #36Phase transitions

2Stability of the object's composition

If stabilization methods are applied to lignin, then thermal stability is improved, but the methods are costly

Engineering Contradiction:
Improvethermal stabilityVSAvoidproduction cost
Core Design Contradiction:
Stability of the object's compositionVSEase of manufacture

Solution Approach 1:

The patent employs self-service through autocatalytic hydrothermal carbonization where the lignin-containing liquid itself provides the catalyst and reaction medium. No external expensive catalysts or stabilization agents are needed, resolving the contradiction between achieving thermal stability and maintaining low production costs.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent uses readily available lignin-containing liquids from industrial waste streams as feedstock, transforming low-value waste into high-value stabilized lignin. This approach resolves the cost contradiction by using inexpensive or free raw materials for stabilization.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Stability of the object's composition

If hydrothermal carbonization is performed, then lignin is converted to carbonized lignin, but control over particle size distribution is unclear

Engineering Contradiction:
Improvethermal stabilityVSAvoidparticle size distribution control
Core Design Contradiction:
Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent establishes precise control over particle size distribution by systematically adjusting hydrothermal carbonization parameters: temperature (150-280°C range), pH (3-11 range), and residence time. These parameter changes enable manufacturing precision while achieving thermal stability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements feedback control by measuring particle size distribution and adjusting hydrothermal carbonization conditions accordingly. This feedback mechanism enables precise control over final particle size while maintaining thermal stability benefits.

Inventive Principle:
Principle #23Feedback

4Manufacturing precision

If separation and purification of carbonized lignin are performed, then defined particle size distribution is achieved, but process complexity increases

Engineering Contradiction:
Improveparticle size distributionVSAvoidseparation process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent simplifies separation by adjusting pH to create equipotential conditions where carbonized lignin particles have uniform charge and size distribution. This enables simple gravity-based or centrifugal separation without complex equipment, achieving manufacturing precision while minimizing device complexity.

Inventive Principle:
Principle #12Equipotentiality

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 enables the production of stabilized lignin with a defined grain size distribution, improving its thermal stability and simplifying separation and purification, while allowing for tailored particle size and polarity adjustments for specific applications.

Implementation Method 1

The lignin-containing liquid is subjected to hydrothermal carbonization at temperatures in a range of approximately 150°C to approximately 280°C, in particular in a temperature range between 180°C and 280°C, and especially in a temperature range between 190°C and 250°C

Methodology Applied
Scientific EffectHydrothermal carbonization:

Implementation Method 2

The particle size distribution of the carbonized lignin is adjusted by adapting the H+ ion concentration in the lignin-containing liquid before and/or during the hydrothermal carbonization

Methodology Applied
Scientific EffectpH control:

Implementation Method 3

the carbonized lignin is separated from the liquid containing the carbonized lignin

Methodology Applied
Scientific EffectSedimentation: Sedimentation

Data Source

PatentEP3177767B1Method for obtaining stabilized lignin having a defined particle-size distribution from a lignin-containing liquid
Publication Date: 2020.04.08 SUNCOAL INDS GMBH
  • EP3177767B1 patent drawingFigure 1~2
  • EP3177767B1 patent drawingFigure 3
  • EP3177767B1 patent drawingFigure 4

AI summary

The invention relates to a method for obtaining stabilized lignin having a defined particle-size distribution from a lignin-containing liquid, wherein prior to and/or during a hydrothermal carbonization, the H+ ion concentration of a lignin-containing liquid is adjusted such that the desired particle-size distribution of the hydrothermal carbonized lignin is obtained, and that it can be separated from the liquid containing the carbonized lignin and can optionally be cleaned.