Lignocellulosic Biomass Pretreatment with Separated Liquid Streams
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing pretreatment processes for lignocellulosic biomass fail to effectively separate and utilize individual liquid streams, leading to inefficiencies in sugar extraction and increased levels of inhibitory compounds like acetic acid and furfural.
Innovation Solution
A process involving soaking, washing, and compressing lignocellulosic biomass to separate free and released liquid streams, where the released liquid is recycled for acid-catalyzed hydrolysis, reducing added acid usage and minimizing sugar contamination in the compression step, followed by a steam explosion reaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If all liquid extraction streams are combined prior to steam explosion, then the process follows conventional design, but the efficiency of sugar extraction is reduced and inhibitory compounds accumulate
Solution Approach 1:
The liquid extraction streams are divided into separate streams rather than being combined. The free liquid stream (containing sugars and inhibitory compounds) is separated from the released liquid stream (containing primarily water and minimal sugars), allowing differential treatment of each stream to maximize sugar recovery while minimizing inhibitor accumulation in the biomass.
Solution Approach 2:
The process extracts and removes the free liquid stream containing dissolved sugars and inhibitory compounds from the biomass before compression. This extraction step prevents the concentration of inhibitory compounds in the final biomass product while recovering valuable sugars for separate processing or utilization.
2Ease of operation
If released liquid is combined with free liquid, then liquid handling is simplified, but sugar contamination increases and acid catalyst usage increases
Solution Approach 1:
The process maintains separate handling paths for free liquid and released liquid streams. The free liquid stream is removed and processed separately, while the released liquid stream is recycled back to the soaking reactor, avoiding contamination and reducing the need for additional acid catalyst.
Solution Approach 2:
The released liquid stream, which contains minimal sugars and inhibitory compounds, is recycled back to the soaking reactor to provide acid-catalyzed hydrolysis conditions. This self-service approach reduces the need for external acid catalyst addition while maintaining effective sugar extraction.
3Productivity
If acid catalyst is added to promote hydrolysis, then sugar extraction improves, but inhibitory compounds increase
Solution Approach 1:
The process utilizes the released liquid stream from compression, which contains natural acetic acid from biomass hydrolysis, and recycles it back to the soaking reactor. This creates a self-sustaining acid-catalyzed hydrolysis system that promotes sugar extraction without requiring external acid catalyst addition, thereby avoiding the formation of additional inhibitory compounds.
Solution Approach 2:
The process changes the approach from adding external acid catalyst to utilizing the naturally occurring acetic acid in the released liquid stream. By controlling the recycling of this stream and maintaining appropriate temperature and pressure conditions, effective hydrolysis is achieved without the harmful effects of excessive acid catalyst.
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 process effectively separates sugars from biomass, maintaining low levels of inhibitory compounds and allowing for efficient recycling of acetic acid, enhancing the accessibility of lignocellulosic content to enzymes while reducing the need for additional acid catalysts.
Implementation Method 1
the feed stock undergoes hydrolysis
Implementation Method 2
compressing the soaked biomass to create a released liquid
Implementation Method 3
the expansion device rapidly releases the pressure of the feed stock discharged from the second pressurized reactor such that the feed stock undergoes a steam explosion reaction
Data Source
Figure 1
AI summary
The process is for pretreating a lignocellulosic biomass feedstock and comprises: soaking a lignocellulosic biomass feedstock wherein the soaked biomass is present as a mixture with a free liquid and wherein the free liquid comprises at least one dissolved compound selected from the group consisting of glucose, xylose and respective oligomers thereof, washing the mixture of the soaked biomass and the free liquid, wherein at least a portion of the free liquid containing at least one dissolved compound selected from the group consisting of glucose, xylose and respective oligomers thereof is separated from the soaked biomass to create a soaked washed biomass and at least one free liquid stream, compressing the soaked biomass to create a released liquid, separating the released liquid from the soaked biomass, and keeping at least a portion of the released liquid separate from any free liquid.