Multi-Point Solvent Injection for Oligosaccharide Recovery
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Solution Overview
Problem
Current processes for producing alcohols from cellulosic materials, such as rice straw, face challenges in efficiently recovering oligosaccharides and recycling acids, particularly in large-scale commercial production, due to limitations in solvent extraction and recycling methods.
Innovation Solution
The process involves introducing an extraction solvent at multiple points along the oligosaccharide flow path in a separator, with controlled timing and positioning to enhance oligosaccharide recovery, and recycling the acid-containing solvent, using a multi-column separator system with mixers and baffles to minimize entrainment and maximize residence time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If extraction solvent is introduced at a single point in the separator, then the process is simple to operate, but oligosaccharide recovery is insufficient
Solution Approach 1:
The extraction solvent introduction system is segmented into multiple injection points along the flow path of the hydrolysate. This segmentation allows the solvent to contact oligosaccharides at different stages of flow, enhancing recovery efficiency while maintaining a relatively simple overall system structure.
Solution Approach 2:
The extraction process transitions from a single-point contact to multi-point contact along the flow path dimension. This dimensional expansion of solvent introduction creates multiple extraction opportunities without significantly increasing system complexity.
2Productivity
If extraction solvent is removed early from the separator, then the residence time is short and processing is efficient, but oligosaccharide recovery is incomplete
Solution Approach 1:
The extraction solvent is introduced at multiple points before the final discharge point, allowing preliminary extraction actions to occur at different stages. This ensures complete oligosaccharide recovery while maintaining efficient processing by removing solvent only at the optimal later point.
3Productivity
If acid-containing extraction solvent is not recycled, then the process is simpler to operate, but acid and extraction solvent are wasted
Solution Approach 1:
Instead of discarding the acid-containing extraction solvent, the system recovers and recycles both the acid and solvent components. This approach improves resource utilization while the integrated design keeps the recovery process manageable.
Solution Approach 2:
The recycled acid and solvent are fed back into the hydrolysis and extraction processes respectively, creating a closed-loop system that improves productivity while maintaining operational simplicity through automated feedback control.
4Productivity
If multiple extraction solvent inlets are used, then oligosaccharide recovery is enhanced, but the device becomes more complex
Solution Approach 1:
The separator system is divided into multiple columns or sections, each with its own extraction solvent inlet. This segmentation enables enhanced oligosaccharide recovery through staged extraction while keeping each individual column relatively simple in design.
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 enhances oligosaccharide recovery and acid recycling, optimizing the production of fermentable sugars and alcohols from cellulosic materials, thereby improving the efficiency and economic viability of biofuel production.
Implementation Method 1
contacting the hydrolysate with an organic extraction solvent, for example methyl ethyl ketone, with separation of the solid lignin and precipitated sugars to yield an acid solution comprising water, extraction solvent, acid and some dissolved sugars
Implementation Method 2
For continuous operation, the extraction solvent is fed into the base of a counterflow separation column and the acid-containing extraction solvent is removed from the top of the column while the hydrolysate is fed into the top of the column and a slurry comprising lignin and undissolved oligosaccharides is removed from the base
Implementation Method 3
The extraction solvent in the acid solution was then evaporated off under vacuum to be recycled and to leave an aqueous acid and sugar solution which was further evaporated off to yield a concentrated acid/sugar mixture
Data Source
AI summary
The invention provides a process for alcohol production from a cellulosic material wherein a said cellulosic material is subjected to acid hydrolysis to yield an aqueous hydrolysate, said hydrolysate is introduced into a separator at a hydrolysate inlet, an extraction solvent is introduced into said separator at at least two extraction solvent inlets, a residue containing oligosaccharides is removed from said separator at a residue discharge outlet, and acid-containing extraction solvent is removed from said separator at an extraction solvent discharge outlet, wherein removal of said extraction solvent from said separator through said discharge outlet occurs downstream of at least one said extraction solvent inlet and upstream of at least one other said extraction solvent inlet.