Non-catalytic Biomass Delignification via Oxygenated Solvent
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Solution Overview
Problem
Current biomass delignification processes are complex, consume high amounts of chemicals, generate significant wastewater, and result in reduced yield and higher modified kappa numbers, necessitating a more efficient and economical method without external catalysts.
Innovation Solution
A non-catalytic delignification method using a treatment liquid mixture of water and oxygenated solvents (30-70% w/w) with an oxygen-containing gas at 120-170°C and 3-100 bar pressure, specifically designed to achieve a modified kappa number below 15, reducing chemical consumption and wastewater while increasing cellulose yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an aqueous organic solvent and catalyst (sulphuric acid) are used to remove lignin and hemicelluloses, then delignification is achieved, but downstream processing complexities increase and yield reduces
Solution Approach 1:
The patent extracts and removes the catalyst (sulphuric acid) from the delignification process, using only an aqueous organic solvent system. This extraction of the harmful catalyst eliminates the formation of side products like furfural and simplifies downstream processing while maintaining effective delignification through the solvent's selective action on lignin and hemicelluloses
Solution Approach 2:
The patent employs a disposable aqueous organic solvent system that can be easily separated and discarded after use, replacing the need for complex catalyst recovery and neutralization processes. The solvent performs its delignification function and is then removed, leaving clean cellulose without requiring additional processing steps
2Manufacturing precision
If catalyst-based delignification is used, then lignin removal is effective, but chemical consumption increases
Solution Approach 1:
The aqueous organic solvent system is self-sufficient for delignification, requiring no external catalyst addition. The solvent naturally selectively dissolves and removes lignin and hemicelluloses through its chemical properties, eliminating the need for continuous catalyst supply and reducing overall chemical consumption while maintaining effective lignin removal
3Manufacturing precision
If traditional delignification processes are used, then lignin is removed, but wastewater load increases
Solution Approach 1:
The patent employs a solvent system that can be easily separated from the delignified cellulose, allowing for recovery and potential reuse. The wastewater generated contains minimal contaminants since no catalyst is used, and the solvent can be recovered through simple separation techniques, significantly reducing the harmful wastewater load compared to traditional catalytic processes
4Manufacturing precision
If catalyst-based processes are used, then delignification occurs, but modified kappa number increases
Solution Approach 1:
By removing the catalyst from the process, the patent prevents the formation of side products and excessive degradation of cellulose that occur with catalytic delignification. The aqueous organic solvent achieves effective lignin removal without increasing the modified kappa number, maintaining higher cellulose quality and purity in the final product
5Manufacturing precision
If complex delignification processes are used, then lignin removal is achieved, but operational robustness decreases
Solution Approach 1:
The patent simplifies the process parameters by eliminating catalyst concentration, temperature control for catalyst activation, and neutralization steps. The aqueous organic solvent system operates under simpler conditions with fewer critical parameters to control, making the process more robust and easier to operate consistently across different scales and conditions
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 effectively reduces chemical usage, wastewater load, and enhances cellulose yield with a lower modified kappa number, making the process more economical and robust, producing high-quality delignified cellulose.
Implementation Method 1
the treatment liquid is a mixture of water and oxygenated solvent... the stream is treated with a treatment liquid in the presence of oxygen-containing gas... to produce a delignified cellulose
Implementation Method 2
the stream is treated with a treatment liquid in the presence of oxygen-containing gas in the apparatus at a temperature of 120-170 °C and initial pressure of 3 to 100 bar
Data Source
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AI summary
The present invention provides a method for non-catalytic delignification of biomass, without externally added catalyst, with a mixed solvent of oxygenated organic solvent and water in the presence of an oxidant, at moderate temperature and pressure. Further, the separation of delignified cellulose from liquid mixture is carried out at around equivalent process conditions. Low modified kappa number delignified cellulose is obtained after separation of a liquid mixture containing a mixed solvent, hemicelluloses, lignin and traces of miscellaneous compounds. Furthermore, the method has lower chemical consumption in the downstream process, ease of operation and robustness.