Modified Acid Delignification and Esterification of Lignocellulosic Biomass
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Solution Overview
Problem
Current processes for delignification of lignocellulosic biomass are inefficient, expensive, and difficult to scale, particularly in separating lignin and hemicellulose from cellulose, which hinders the use of biomass as a viable alternative to fossil fuel-based products.
Innovation Solution
A combined lignin depolymerization and esterification reaction method that treats lignocellulosic biomass to convert lignin into small chemicals, using an acidic composition with a pH of less than 1, comprising sulfuric acid, a source of peroxide, and an alcohol, to achieve delignification and esterification in a single step.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional kraft process is used for delignification, then lignin can be removed from biomass, but high energy input in the form of heat and pressure is required
Solution Approach 1:
The patent changes the chemical parameters of the delignification process by using modified Caro's acid (peroxymonosulfuric acid) instead of conventional kraft chemicals, enabling the reaction to proceed at reduced temperatures and pressures while maintaining effective lignin removal
Solution Approach 2:
The patent employs modified Caro's acid, a strong oxidizing agent, to accelerate the delignification reaction. This allows the process to achieve effective lignin removal under milder conditions (lower temperature and pressure) compared to conventional kraft process, thereby reducing energy input
2Reliability
If conventional delignification processes are used, then lignin can be separated from cellulose, but the process is inefficient and expensive
Solution Approach 1:
The patent combines delignification and esterification reactions into a single integrated process step. The modified Caro's acid simultaneously removes lignin from biomass and esterifies the released lignin compounds, improving overall process efficiency and reducing the number of separate processing steps required
Solution Approach 2:
The esterification reaction is performed in-situ during delignification, where the lignin compounds released from biomass automatically undergo esterification with the modified Caro's acid without requiring separate extraction and processing steps, thereby improving productivity and reducing costs
3Reliability
If conventional delignification is performed, then lignin fragments are obtained, but they tend to condense and become difficult to remove
Solution Approach 1:
The patent applies preliminary anti-action by performing esterification concurrently with delignification. The esterification reaction modifies the lignin fragments as they are released, preventing them from undergoing condensation reactions that would make them difficult to remove and process further
4Adaptability or versatility
If existing infrastructure is utilized for biomass processing, then current oil & gas infrastructure can be used, but the biomass must be converted to fuels through energy-intensive processes
Solution Approach 1:
The patent changes the physical state and chemical composition of lignin products through esterification, transforming them into liquid hydrocarbon-like compounds that can be directly compatible with existing oil and gas infrastructure without requiring additional energy-intensive conversion steps such as pyrolysis or gasification
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 method effectively delignifies biomass at reduced temperatures and pressures, minimizing energy input and capital expenditures, while producing valuable ester compounds such as vanillate esters and diesters, which are not accessible through conventional two-step processes.
Implementation Method 1
a combined lignin depolymerization and esterification reaction method that treats lignocellulosic biomass to convert lignin into small chemicals
Implementation Method 2
an acidic composition with a pH of less than 1, comprising sulfuric acid, a source of peroxide, and an alcohol
Implementation Method 3
a combined lignin depolymerization and esterification reaction method that treats lignocellulosic biomass to convert lignin into small chemicals
Data Source
AI summary
Method for controlled delignification of lignocellulosic feedstock and conversion of lignin depolymerization products into at least one ester compound, said method comprising the steps of: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; andan arylsulfonic acid;a source of peroxide;an alcohol selected from the group consisting of C1-C6 linear alcohol and C3-C6 branched alcohol and mixtures thereof;exposing said lignocellulosic feedstock to said acidic composition for a period of time sufficient for the acidic composition to react with the lignocellulosic feedstock to obtain a liquid phase containing lignin depolymerization products and diester compounds and a solid phase comprising cellulose fibers;optionally, separating the liquid phase from the solid phase recovering a mixture of diesters, lignin monomers and cellulose fibers; andoptionally, separating said lignin depolymerization products from said diester compounds.