Lignin Esterification via Modified Caro's Acid Delignification

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Solution Overview

Problem

Current methods for converting lignin from biomass into valuable chemicals are inefficient, often resulting in unstable bio-oils with high oxygen content, and are hindered by lignin's complex structure and susceptibility to condensation reactions.

Innovation Solution

A method using a modified Caro's acid delignification process to convert lignin into lignin-derived material (LHDO), which is then esterified to produce valuable aromatic and aliphatic esters, overcoming issues of aldehyde production and acid stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional delignification methods are used to convert lignin into chemicals, then the process is simple and widely available, but the products are unstable bio-oils with high oxygen content

Engineering Contradiction:
Improveproduct stabilityVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the chemical parameters of the delignification process by using modified Caro's acid (peroxymonosulfuric acid) instead of conventional methods. This chemical parameter change transforms the product from unstable bio-oil to stable lignin-derived material with reduced oxygen content, resolving the contradiction between product stability and process complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs modified Caro's acid, a strong oxidizing agent, to accelerate the oxidation process during delignification. This strong oxidation breaks down the complex lignin structure more effectively, producing stable aromatic compounds with lower oxygen content, thereby improving product stability while maintaining reasonable process complexity.

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

2Quantity of substance

If lignin is depolymerized to obtain aromatic monomers, then valuable chemicals can be produced, but lignin condensation reactions hinder the isolation of constituents

Engineering Contradiction:
Improveyield of aromatic monomersVSAvoidlignin condensation
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by performing delignification and depolymerization simultaneously using modified Caro's acid before condensation can occur. This preliminary breakdown of lignin into monomeric units prevents subsequent condensation reactions, maximizing the yield of aromatic monomers and resolving the contradiction between quantity produced and harmful condensation effects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The strong oxidizing action of modified Caro's acid rapidly depolymerizes lignin into monomeric units faster than condensation reactions can occur. This kinetic advantage prevents lignin condensation, allowing high yields of aromatic monomers to be achieved while minimizing the harmful condensation effect.

Inventive Principle:
Principle #38Strong oxidants (Accelerated oxidation)

3Quantity of substance

If esterification is performed on lignin-derived material, then valuable ester compounds are produced, but water content must be reduced first

Engineering Contradiction:
Improveyield of ester compoundsVSAvoidprocess steps
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent applies preliminary action by performing water removal (concentration) as a prerequisite step before esterification. This preliminary concentration of lignin-derived material reduces water content to levels that enable effective esterification, maximizing the yield of ester compounds while organizing the process steps logically.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent uses an intermediary concentration step that transforms the aqueous lignin-derived material into a more concentrated form suitable for esterification. This intermediary state serves as a bridge between the delignification step and the esterification step, enabling the overall process to proceed efficiently.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 high yields of valuable ester compounds, reduces water content, and enhances the stability and hydrophobicity of the products, making them more suitable for further chemical processing and utilization.

Implementation Method 1

a method using a modified Caro's acid delignification process to convert lignin into lignin-derived material

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

which is then esterified to produce valuable aromatic and aliphatic esters

Methodology Applied
Scientific EffectEsterification: Chemical Bonding

Implementation Method 3

heating up said mixture to a temperature ranging from 25° C. to 120° C.

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentUS20250042834A1Fischer Esterification of Lignin-Derived Material
Publication Date: 2025.02.06 SIXRING INC

AI summary

A method for converting a lignin-derived material into at least one esterified lignin derivative, said method comprising the steps of:providing said lignin-derived material selected from the group consisting of: lignin monomers; lignin depolymerization products; and combinations thereof;providing an acidic composition having a pH of less than 1, said acidic composition comprising:an acid selected from the group consisting of: sulfuric acid; an alkylsulfonic acid; and an arylsulfonic acid; andan alcohol selected from the group consisting of C1-C8 linear alcohol and C3-C8 branched alcohol and mixtures thereof;combining said lignin-derived material with said acidic composition into a reaction mixture;heating up said mixture to a temperature ranging from 25° C. to 120° C.; andallowing sufficient time of reaction to convert at least a portion of said lignin-derived material into said at least one esterified lignin derivative.