Fermentation Broth Carboxylic Acid Recovery via Supercritical Esterification
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Solution Overview
Problem
Current methods for recovering polycarboxylic acids from fermentation broths are costly and inefficient, requiring multiple steps and generating significant waste due to the need for salt formation and subsequent neutralization, which increases processing costs and environmental impact.
Innovation Solution
A process involving the conversion of polycarboxylic acids to their corresponding esters under supercritical or critical conditions using a CO2 atmosphere without additional acid catalysts, allowing for direct recovery and recycling of by-products, thereby simplifying downstream processing and reducing waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If calcium carbonate is used to maintain pH during fermentation, then the diacid is recovered as calcium salt, but the calcium salt has very low solubility and is not suitable for many applications requiring free acid
Solution Approach 1:
The patent changes the pH parameter during fermentation to maintain it below the pKa of the carboxylic acid, preventing salt formation and enabling direct recovery of free acid. This parameter change resolves the contradiction by allowing the acid to be recovered in its free form rather than as insoluble calcium salt.
Solution Approach 2:
Instead of the conventional approach of forming salts and then converting them to free acid, the patent inverts the process by preventing salt formation altogether through pH control, directly obtaining free acid suitable for various applications.
2Adaptability or versatility
If magnesium oxygen compounds are used to maintain pH, then the free acid can be produced, but the process becomes expensive due to higher cost of magnesium compounds and additional energy costs for temperature reduction
Solution Approach 1:
The patent changes the pH parameter to remain below the acid's pKa throughout fermentation, eliminating the need for expensive magnesium compounds and subsequent cooling steps. This approach produces free acid directly while avoiding additional energy costs.
3Productivity
If conventional salt formation and neutralization steps are used for acid recovery, then the acid can be separated, but multiple processing steps are required generating significant waste and increasing costs
Solution Approach 1:
The patent extracts the acid in its free form directly from the fermentation broth by maintaining pH below the pKa, eliminating the need for salt formation and neutralization steps. This simplifies the process by removing unnecessary processing steps and reduces waste generation.
Solution Approach 2:
The fermentation system itself maintains conditions that prevent salt formation when pH is controlled below pKa, allowing direct free acid recovery without additional processing steps for salt formation and subsequent neutralization.
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 enables efficient and cost-effective recovery of polycarboxylic acids as esters, reducing processing steps and waste generation, and allows for the recycling of by-products back into the fermentation process, improving overall efficiency and sustainability.
Implementation Method 1
synthesizing an ester by reacting said polycarboxylic acid in said powder with an alcohol solvent under a CO2 atmosphere, where any other acid catalyst is present at a level less than 10% weight/weight relative to the polycarboxylic acid in the reaction, at either a reaction temperature or pressure or both which corresponds to supercritical, critical, or near critical conditions for at least one of said alcohol or CO2
Implementation Method 2
at either a reaction temperature or pressure or both which corresponds to supercritical, critical, or near critical conditions for at least one of said alcohol or CO2
Data Source
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AI summary
A process for recovering and using an carboxylic acid derived from a fermentation broth by means of making an ester of the free carboxylic acid and alcohol in carbon dioxide (CO2) without the presence of any other acid catalyst at a reaction temperature and pressure that corresponds to supercritical, critical or near critical conditions for the alcohol and/or CO2 is described. The process can constitute part of a general process of refining carboxylic acids derived from a fermentation broth for use in the production of a variety of chemical compounds, such as C4 platform compounds, polymers, or fuels.