Butanol Esterification for Fermentation Toxicity and Extractant Degradation
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Solution Overview
Problem
Existing methods for butanol production in fermentation face challenges due to low butanol toxicity thresholds in microorganisms, leading to inefficient production and extractive fermentation processes that require costly fractionation and result in degradation of the partition coefficient of the extractant, especially with lipid contamination.
Innovation Solution
Converting butanol into butyl esters by contacting it with carboxylic acids and catalysts, such as enzymes, to form a two-phase mixture where the esters can be separated and recycled, reducing lipid contamination and maintaining high production yields without the need for extensive fractionation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If liquid-liquid extraction is used to remove butanol from fermentation medium, then butanol toxicity to microorganisms is reduced, but extractant partition coefficient degrades due to lipid contamination
Solution Approach 1:
The patent extracts lipids from the fermentation medium before the extraction process begins. By removing lipids upfront using adsorbents or centrifugation, the extractant is protected from contamination that would otherwise degrade its partition coefficient over time, while still maintaining the ability to extract butanol effectively.
Solution Approach 2:
The patent performs preliminary lipid removal from the fermentation medium before initiating the liquid-liquid extraction process. This preliminary action prevents lipid accumulation in the extractant, thereby maintaining the extractant's partition coefficient stability throughout the fermentation and extraction operations.
2Quantity of substance
If extensive fractionation is performed to remove lipids from extractant, then extractant purity is improved, but process complexity and cost increase
Solution Approach 1:
Instead of using complex fractionation processes to remove lipids from the extractant after contamination, the patent extracts lipids from the fermentation medium beforehand. This approach achieves the same purity goal with simpler, less costly operations.
Solution Approach 2:
The patent inverts the conventional approach by removing lipids from the fermentation medium before extraction rather than removing lipids from the extractant after it has been contaminated. This reversal simplifies the overall process while achieving the same result.
3Productivity
If butanol concentration is allowed to increase in fermentation medium, then production yield is improved, but microorganism viability decreases due to toxicity
Solution Approach 1:
The patent introduces an intermediary extraction step that acts as a mediator between butanol production and microorganism viability. The extractant continuously removes butanol from the fermentation medium, maintaining a safe concentration for the microorganisms while still achieving high overall production yields through accumulated extraction.
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 method allows for increased butanol production by reducing toxic effects on microorganisms and minimizing extractant degradation, enhancing fermentation efficiency and economic viability.
Implementation Method 1
the fermentation medium which includes the microorganism is contacted with an organic extractant at a time before the butanol concentration reaches a toxic level. The organic extractant and the fermentation medium form a biphasic mixture. The butanol partitions into the organic extractant phase decreasing the concentration of butanol in the aqueous phase containing the microorganism
Implementation Method 2
The butanol partitions into the organic extractant phase decreasing the concentration of butanol in the aqueous phase
Implementation Method 3
converting butanol into butyl esters by contacting it with carboxylic acids and catalysts, such as enzymes, to form a two-phase mixture
Implementation Method 4
The catalyst can be supplied to the feedstock prior to fermentation or can be supplied to the fermentation vessel before or contemporaneously with the supplying of the feedstock. When the catalyst is supplied to the fermentation vessel, alcohol esters can be obtained by hydrolysis of the lipids into carboxylic acid
Data Source
AI summary
An alcohol fermentation process and composition that includes production of alcohol esters by esterification of product alcohol in a fermentation medium with a carboxylic acid (e.g., fatty acid) and a catalyst (e.g., lipase) capable of esterifying the product alcohol, such as butanol, with the carboxylic acid to form the alcohol esters. The alcohol esters can be extracted from the fermentation medium, and the product alcohol recovered from the alcohol esters. The carboxylic acid can also serve as an extractant for removal of the alcohol esters from the fermentation medium.