Biomass Cooling via Dewatering and Segmentation
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Solution Overview
Problem
Current biomass treatment methods face inefficiencies in cooling and achieving high biomass concentrations in the slurry for effective hydrolysis and post-processing, leading to suboptimal enzymatic activity and increased costs due to low cooling efficiency and excessive liquid handling.
Innovation Solution
A method involving prehydrolysis, dewatering, and cooling of biomass using a liquid at a lower temperature, followed by enzymatic hydrolysis, which includes a pressurized prehydrolysis reactor, dewatering unit, and cooling unit to efficiently adjust biomass concentration and temperature for optimal hydrolysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If cold liquid is added to cool the pretreated biomass, then the temperature is reduced to the required range, but the biomass concentration in the slurry decreases below 15 wt%, requiring additional liquid removal and increasing processing costs
Solution Approach 1:
The cooling process is segmented into two distinct stages: first dewatering the hot pretreated biomass to concentrate it, then cooling the dewatered biomass with cold liquid. This segmentation allows achieving both high biomass concentration (15-25 wt%) and appropriate cooling without the trade-off present in conventional single-step cooling methods.
Solution Approach 2:
Dewatering is performed as a preliminary action before cooling. By removing excess liquid first, the biomass concentration is increased to the optimal range for enzymatic hydrolysis, and then cooling can be applied without diluting the biomass further. This preliminary dewatering step prevents the need for additional liquid removal after cooling.
2Temperature
If heat exchangers are used to cool the pretreated biomass, then the temperature is reduced, but the cooling efficiency is low and the equipment can easily plug
Solution Approach 1:
The problematic heat exchanger component is extracted from the process sequence. Instead of using heat exchangers for cooling, the invention employs direct mixing with cold liquid after dewatering. This eliminates the heat exchanger entirely, avoiding its low cooling efficiency and plugging issues while maintaining effective temperature reduction.
Solution Approach 2:
The thermal exchange mechanism of heat exchangers is replaced with a mechanical mixing approach. Cold liquid is directly mixed with the dewatered biomass in a mixing vessel, transferring heat through the liquid-biomass interface. This substitution of the cooling mechanism eliminates the mechanical and thermal inefficiencies of heat exchangers.
3Temperature
If the weight amount of biomass in the slurry is reduced below 15 wt%, then more liquid can be added for cooling, but enzymatic hydrolysis becomes suboptimal and processing costs increase
Solution Approach 1:
Dewatering is performed as a preliminary action before cooling. By removing excess liquid first, the biomass concentration is increased to the optimal range for enzymatic hydrolysis, and then cooling can be applied without diluting the biomass further. This preliminary dewatering step prevents the need for additional liquid removal after cooling.
Solution Approach 2:
The cooling process is segmented into two distinct stages: first dewatering the hot pretreated biomass to concentrate it, then cooling the dewatered biomass with cold liquid. This segmentation allows achieving both high biomass concentration (15-25 wt%) and appropriate cooling without the trade-off present in conventional single-step cooling methods.
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 enables efficient cooling and concentration adjustment of biomass slurry, enhancing enzymatic hydrolysis efficiency and reducing downstream processing costs by minimizing liquid handling and optimizing biomass concentration.
Implementation Method 1
a dewatering unit for separating the discharged thermally treated aqueous slurry of biomass into a dewatered thermally treated aqueous slurry of biomass and a filtrate of hot aqueous solution
Implementation Method 2
Cooling the dewatered thermally treated aqueous slurry of biomass by mixing the dewatered thermally treated aqueous slurry of biomass with a liquid which has a lower temperature than the dewatered thermally treated aqueous slurry of biomass in the cooling unit
Implementation Method 3
Thermally treating the biomass in the pressurized prehydrolysis reactor unit
Implementation Method 4
Feeding biomass to a pressurized prehydrolysis reactor unit
Implementation Method 5
Treating the cooled aqueous slurry of biomass with an enzyme
Implementation Method 6
enzymatic hydrolysis step
Data Source
Figure 1
AI summary
The present invention relates to an improved method and device for treating biomass in which thermally treated biomass is discharged from a pressurized prehydrolysis reactor unit and dewatered before it is cooled with cold liquid. The cooled slurry of biomass is then enzymatically treated.