Modified Sulfuric Acid Composition for Low-Energy Biomass Delignification

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Solution Overview

Problem

Current pulping processes, particularly the kraft process, are energy-intensive and emit substantial odors and emissions, making them environmentally and economically inefficient, and there is a need for a more efficient delignification method that does not require high temperatures and pressures.

Innovation Solution

An aqueous acidic composition comprising sulfuric acid, alkanesulfonic acid, and peroxide is used to delignify biomass at room temperature, reducing energy and pressure requirements, and includes a molar ratio of sulfuric acid to alkanesulfonic acid ranging from 1:1 to 30:1, allowing for efficient lignin removal with minimal cellulose degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If the kraft process is used for delignification, then effective lignin removal is achieved, but high energy consumption and high capital expenditures are required due to high temperatures and pressures

Engineering Contradiction:
Improvelignin removal efficiencyVSAvoidenergy consumption
Core Design Contradiction:
Loss of substanceVSUse of energy by moving object

Solution Approach 1:

The patent changes the chemical parameters by introducing a modified sulfuric acid composition with specific additives (sodium metabisulfite and formaldehyde) that enable delignification to proceed effectively at lower temperatures (20-60°C) and atmospheric pressure, thereby reducing energy consumption while maintaining lignin removal efficiency

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses sodium metabisulfite and formaldehyde as intermediary substances that facilitate the delignification process under milder conditions. These additives act as mediators that enhance the effectiveness of modified sulfuric acid, allowing lignin degradation without requiring the extreme temperatures and pressures of conventional kraft processing

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of substance

If the kraft process is used for delignification, then effective lignin removal is achieved, but high capital expenditures are required for high temperature and pressure equipment

Engineering Contradiction:
Improvelignin removal efficiencyVSAvoidcapital expenditures
Core Design Contradiction:
Loss of substanceVSEase of manufacture

Solution Approach 1:

By changing the temperature and pressure parameters to lower values (20-60°C and atmospheric pressure), the patent eliminates the need for expensive high-pressure vessels and high-temperature equipment, thereby reducing capital expenditures while achieving effective delignification through chemical modification

Inventive Principle:
Principle #35Parameter changes

3Loss of substance

If conventional sulfuric acid and peroxide are used, then delignification can occur, but the composition is aggressive and presents handling difficulties

Engineering Contradiction:
Improvelignin removalVSAvoidhandling safety
Core Design Contradiction:
Loss of substanceVSEase of operation

Solution Approach 1:

The patent modifies the sulfuric acid composition by adding sodium metabisulfite and formaldehyde, which alter the chemical reactivity profile. This modification reduces the aggressive nature of the composition while maintaining delignification effectiveness, making it safer and easier to handle during operation

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite chemical composition by combining sulfuric acid with sodium metabisulfite and formaldehyde. This composite formulation achieves synergistic effects where the combined components provide effective delignification with reduced aggression and improved handling characteristics compared to conventional sulfuric acid and peroxide mixtures

Inventive Principle:
Principle #40Composite materials

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 achieves delignification at significantly lower temperatures (20-60°C) and atmospheric pressure, reducing energy consumption, emissions, and capital expenditures while maintaining high cellulose yield and safety, suitable for large-scale operations.

Implementation Method 1

decomposing organic material by oxidation such as, but not limited to, the delignification of wood or plant substance

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

an aqueous acidic composition comprising sulfuric acid, alkanesulfonic acid, and peroxide

Methodology Applied
Scientific EffectPeroxide oxidation: Oxidation

Data Source

PatentUS12371854B2Modified sulfuric acid and uses thereof
Publication Date: 2025.07.29 SIXRING INC

AI summary

One-pot processes to separate lignin from a lignocellulosic feedstock include providing a vessel; providing a lignocellulosic feedstock; providing a composition comprising an acid, a modifying agent comprising an alkanesulfonic acid, and a peroxide; and exposing the lignocellulosic feedstock to the composition in the vessel for a period of time sufficient to remove at least 80% of the lignin present in the lignocellulosic feedstock. In some instances, such one-pot process can further include removing a liquid phase comprising dissolved lignin fragments from a solid phase comprising cellulose fibres.