Granular Carbon Production from Lignin Without Swelling or Dusting

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Solution Overview

Problem

Conventional methods for converting lignin into carbon-enriched materials face issues such as plastic deformation, melting, aggressive swelling, and foaming during thermal conversion, which limit processability and scalability, especially when using lignin powder.

Innovation Solution

A process involving agglomeration and thermal stabilization of lignin into macroscopic particles, followed by controlled heating to retain shape and dimension, producing granular carbon suitable for various applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If lignin powder is used as raw material for thermal conversion, then the process can be simple and direct, but the lignin undergoes plastic deformation, melting, aggressive swelling and foaming which severely limits processability

Engineering Contradiction:
Improveprocess simplicityVSAvoidprocessability
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent applies preliminary action by agglomerating lignin powder into granules before thermal conversion. This pre-treatment step creates larger particles with reduced surface area to volume ratio, which prevents the plastic deformation and melting issues that occur with fine powder during subsequent heating processes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the physical parameter of lignin particle size from fine powder to granules through agglomeration. This parameter change fundamentally alters the thermal behavior during conversion, eliminating the harmful plastic deformation and foaming while maintaining process simplicity.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If lignin is heated for thermal conversion, then carbon-enriched intermediates can be produced, but aggressive swelling and foaming occur which limits equipment dimensioning and process throughput

Engineering Contradiction:
Improveprocess throughputVSAvoidequipment dimensioning
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

By agglomerating lignin into granules before processing, the patent performs a preliminary action that prevents aggressive swelling during heating. This allows for more compact equipment design and higher process throughput since the granules maintain their structural integrity during thermal conversion.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If lignin powder is handled during processing, then the material can be processed, but strong tendency for dust formation occurs which limits industrial scale processing

Engineering Contradiction:
ImproveprocessabilityVSAvoiddust formation
Core Design Contradiction:
Ease of manufactureVSObject-generated harmful factors

Solution Approach 1:

The patent changes the physical state of lignin from fine powder to granules through agglomeration. This parameter change eliminates dust formation during handling while maintaining all necessary processability requirements for industrial-scale manufacturing.

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

The process enables the production of granular carbon that maintains its shape and dimension, reducing dusting and facilitating the production of bio-chars and activated carbons, suitable for large-scale industrial use.

Implementation Method 1

heating the agglomerated lignin to a temperature in the range of from 180 to 250°C for a period of at least 1.5 hours and less than 12 hours, to obtain thermally stabilized agglomerated lignin; subjecting the thermally stabilized agglomerated lignin to heat treatment at one or more temperatures in the range of from 300°C to 1500°C

Methodology Applied
Scientific EffectPyrolysis: Pyrolysis

Data Source

PatentEP4165056B1Process for producing carbon from heat treated lignin
Publication Date: 2026.04.22 STORA ENSO OYJ

AI summary

The present invention is directed to production of granular carbon, prepared from lignin. The process comprises the steps of providing agglomerated lignin, heating the agglomerated lignin to obtain thermally stabilized lignin and subjecting the thermally stabilized agglomerated lignin to heat treatment to obtain granular carbon.