Nanofiltration Membrane Separation of Lignin and Sugars
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Solution Overview
Problem
Current methods for separating lignin and monomeric sugars from organosolv liquors are energy-intensive and costly due to the need for distillation, limiting the economic viability of biomass conversion processes for biofuels and chemicals.
Innovation Solution
A process utilizing membrane filtration techniques, specifically nanofiltration and selective permeation, to separate lignin and monomeric sugars without the need for distillation, allowing for the reuse of solvents and reducing energy consumption by passive cooling, thereby isolating both components efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If distillation is used to separate lignin and monomeric sugars from organosolv liquor, then separation efficiency is improved, but energy consumption increases significantly
Solution Approach 1:
The patent replaces the thermal distillation system with a membrane filtration system that uses mechanical pressure differential instead of thermal energy to achieve separation. The nanofiltration membrane physically separates lignin and monomeric sugars from the organosolv liquor based on size exclusion, eliminating the need for energy-intensive heating and condensation cycles while maintaining high separation efficiency.
Solution Approach 2:
The patent employs nanofiltration membranes with specific pore sizes and selective permeability properties to separate different components of the organosolv liquor. The porous membrane structure allows monomeric sugars to pass through while retaining larger lignin molecules, providing efficient separation without thermal processing and enabling solvent reuse.
2Manufacturing precision
If distillation is used to separate and recover solvents from organosolv liquor, then solvent purity is improved, but process cost increases
Solution Approach 1:
The patent replaces costly thermal distillation with affordable membrane filtration technology. The nanofiltration process achieves effective solvent separation and purification at a fraction of the energy and operational costs associated with distillation, making the overall process economically viable while maintaining solvent purity suitable for reuse.
Solution Approach 2:
The patent changes the separation parameter from thermal gradient (distillation) to pressure gradient (membrane filtration). This parameter change enables solvent recovery at lower temperatures and pressures, reducing equipment requirements and operational costs while achieving the necessary solvent purity for循环利用 in the organosolv process.
3Ease of operation
If dilution with water is used to precipitate lignin from organosolv liquor, then lignin separation is simplified, but process economy deteriorates due to increased energy input for subsequent distillation
Solution Approach 1:
The patent replaces the two-step process of water dilution followed by thermal distillation with a direct membrane filtration approach. The nanofiltration membrane enables lignin precipitation and separation in a single step without requiring water dilution or subsequent energy-intensive distillation, maintaining operational simplicity while eliminating the energy penalty.
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 approach significantly reduces energy and costs associated with separation, enabling the efficient recovery of lignin and monomeric sugars for further use, enhancing the economic attractiveness of biomass conversion to biofuels and chemicals.
Implementation Method 1
subjecting the solution to nanofiltration over a membrane capable of retaining lignin and permeating at least monomeric sugars
Implementation Method 2
subjecting a permeate originating from step (a) to selective permeation using a membrane selective for permeation of water molecules
Implementation Method 3
subjecting a permeate originating from step (a) to selective permeation using a membrane selective for permeation of water molecules to obtain a suspension containing precipitated monomeric sugars
Implementation Method 4
precipitating lignin from a retentate originating from step (a)
Data Source
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AI summary
The invention relates to an improved process for separating lignin and monomeric sugars from a liquor comprising lignin and monomeric sugars in a solvent mixture of water and at least one organic solvent, which employs membrane filtration techniques such as nanofiltration and selective water removal, preferably bypermeation through a membrane which is selective for water molecules. The invention further relates to a modular system for executing the process according to the invention. The process and system according to the invention are particularly suitable to be incorporated with pre-treatment of lignocellulosic biomass, in particular by organosolv fractionation or solvolysis.