Lactic Ester Production via Reactive Distillation
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Solution Overview
Problem
Current industrial processes for producing lactic esters from fermentation juice containing ammonium lactate face challenges such as simultaneous production of gypsum, low yield, significant loss of lactic ester as lactamide, and racemization, making it difficult to scale up and environmentally costly.
Innovation Solution
A process involving pre-purification, concentration, and reactive distillation of ammonium lactate with an aliphatic alcohol in a 3-stage column, minimizing lactamide formation and racemization, and achieving high yield and purity of lactic ester without gypsum production.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a large molar excess of alcohol (20-100 moles per mole of ammonium lactate) is used to avoid lactamide formation, then selectivity improves, but energy consumption increases significantly due to distillation requirements
Solution Approach 1:
The invention changes the concentration parameter from using large excess of alcohol (20-100 moles) to a controlled molar ratio (1.05-2.0 moles), and changes the reaction condition from batch to continuous reactive distillation, thereby reducing energy consumption while maintaining selectivity
Solution Approach 2:
The invention implements continuous reactive distillation where the esterification reaction and separation occur simultaneously and continuously, allowing immediate removal of water and alcohol to drive the reaction forward without requiring large excess of alcohol, thus reducing energy consumption for subsequent distillation
2Ease of manufacture
If fermentation by-products are present in the fermentation juice, then the process uses unpurified ammonium lactate, but precipitation occurs during concentration and esterification making the process difficult and reducing yield
Solution Approach 1:
The invention performs preliminary filtration of the fermentation juice before concentration and esterification steps to remove fermentation by-products and precipitates, thereby preventing precipitation issues during subsequent processing and maintaining high esterification yield
Solution Approach 2:
The invention extracts and removes fermentation by-products and precipitates from the fermentation juice through filtration before the concentration and esterification steps, separating the harmful components from the useful ammonium lactate
3Object-affected harmful factors
If the process uses ammonium salts to produce lactic acid esters without gypsum, then environmental impact is reduced, but lactamide formation decreases selectivity and yield
Solution Approach 1:
The invention uses continuous reactive distillation where the esterification reaction and separation occur simultaneously, allowing immediate removal of water to drive the reaction forward and prevent lactamide formation, thereby maintaining high selectivity while using ammonium salts for environmental benefits
Solution Approach 2:
The invention changes the reaction conditions by implementing continuous reactive distillation with controlled molar ratios and temperature, which prevents lactamide formation and maintains high selectivity while using ammonium salts instead of calcium carbonate
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
The process achieves a lactic ester yield greater than 95% with less than 5% lactamide loss and racemization below 2%, effectively addressing the limitations of existing methods and enabling environmentally friendly and cost-effective production.
Implementation Method 1
reactive distillation of ammonium lactate with an aliphatic alcohol in a 3-stage column
Implementation Method 2
concentration and then to reactive distillation
Data Source
Figure 1
AI summary
The present invention relates to an industrial process for producing a lactic ester containing in total at least seven carbon atoms, from a fermentation liquor containing ammonium lactate in order to avoid the inherent production of gypsum, with a high yield and according to which the loss of lactic ester in the form of lactamide is limited as much as possible.