Fed Batch Biomass Saccharification with Particle Size Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Achieving high concentrations of fermentable sugars in biomass hydrolysates for economical ethanol production has been challenging due to difficulties in maintaining thorough mixing and pH/temperature control in high dry weight biomass saccharification processes, especially in traditional reactor systems.
Innovation Solution
A fed batch reactor system with multiple size reduction steps and thorough mixing in a vertical, agitated tank is used, incorporating a particle size reduction mechanism and sequential additions of pretreated biomass and saccharification enzymes to maintain low yield stress and achieve high sugar content hydrolysates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If high dry weight biomass content is used in saccharification process, then sugar concentration in hydrolysate is improved, but mixing and pH/temperature control becomes difficult
Solution Approach 1:
The biomass is divided into smaller particles through size reduction mechanisms (grinders, mills, or shear forces) to reduce slurry viscosity and improve mixability. This segmentation allows high biomass dry weight content (≥20%, preferably ≥30%) to be maintained while enabling thorough mixing and proper pH/temperature control in traditional stirred tank reactors.
Solution Approach 2:
The process changes the physical parameter of particle size by applying mechanical size reduction during the saccharification process. This parameter change reduces the yield stress and viscosity of the biomass slurry, allowing high solids content to be processed with adequate mixing and control in conventional reactor systems.
2Ease of manufacture
If traditional stirred tank reactor system is used, then capital cost is reduced, but thorough mixing at high biomass concentration cannot be maintained
Solution Approach 1:
Biomass size reduction is performed preliminarily or concurrently with saccharification to prepare the slurry for effective mixing. By reducing particle size before or during the reaction, the slurry viscosity is lowered in advance, enabling traditional stirred tank reactors to achieve thorough mixing at high biomass concentrations that would otherwise be impossible.
Solution Approach 2:
The system dynamically adjusts biomass particle size through size reduction mechanisms activated during the process. This dynamic modification of particle dimensions allows the slurry rheology to change from a mixing-resistant state to a mixable state, enabling conventional reactors to operate effectively at high solids content.
3Productivity
If multiple size reduction steps are applied, then sugar yield is improved, but process complexity increases
Solution Approach 1:
Multiple size reduction steps are merged and integrated within the single saccharification process. The biomass undergoes size reduction either before enzyme addition or concurrently during saccharification, combining what would otherwise be separate preprocessing and reaction stages into a unified process that achieves high sugar yield without proportionally increasing complexity.
Solution Approach 2:
The size reduction action continues throughout the saccharification process rather than being a discrete preliminary step. This continuous or repeated size reduction maintains optimal particle dimensions for enzyme access throughout the reaction, maximizing sugar yield while using the same reactor system for both size reduction and saccharification.
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 enables the production of high concentration sugar hydrolysates with yields of up to 95% glucose, facilitating economical fermentation of valuable products like ethanol while maintaining low capital and energy costs.
Implementation Method 1
applying the particle size reduction mechanism
Implementation Method 2
a portion of a first saccharification enzyme consortium comprising at least one enzyme capable of hydrolyzing cellulose
Implementation Method 3
Saccharification enzymes used to produce fermentable sugars from pretreated biomass typically include one or more glycosidases
Implementation Method 4
mixing to maintain thorough mixing in a vertical, agitated tank
Data Source
AI summary
Processes for saccharification of pretreated biomass to obtain high concentrations of fermentable sugars are provided. Specifically, a process was developed that uses a fed batch approach with particle size reduction to provide a high dry weight of biomass content enzymatic saccharification reaction, which produces a high sugars concentration hydrolysate, using a low cost reactor system.