Ethanol Separation from Fermented Broth at Low Temperatures
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Solution Overview
Problem
Conventional ethanol separation methods from fermented broths containing live microorganisms are inefficient due to high temperatures that kill microbes, high energy consumption, and increased capital and operating expenses, particularly in gas fermentation processes where low temperature and short residence time are critical for maintaining microbial activity.
Innovation Solution
An integrated process utilizing a broth stripper column (vacuum distillation system) and a vapor compressing unit (turbofans) with a falling film evaporator, operating at temperatures below 50°C and residence times of 1-10 minutes, which effectively separates ethanol and other organic compounds while protecting live microbes and reducing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional distillation is used for ethanol separation, then ethanol recovery efficiency is improved, but microorganisms are killed due to high temperature
Solution Approach 1:
The patent changes the operating parameters of the distillation system by operating under vacuum conditions (reduced pressure), which allows ethanol separation at temperatures below 50°C instead of conventional high temperatures, thereby preserving microorganism viability while maintaining separation efficiency
Solution Approach 2:
The patent utilizes phase transition of water from liquid to vapor through evaporators, where water evaporates at low temperature under vacuum conditions to strip ethanol from the broth, and the vapor is then condensed back to liquid form, enabling separation without thermal damage to microorganisms
2Temperature
If membrane separation is used for ethanol recovery, then low temperature operation is achieved, but capital expenditure and maintenance cost increase
Solution Approach 1:
The patent replaces the membrane separation system with a thermal-based vacuum distillation system using evaporators and condensers, eliminating the need for expensive membrane modules while achieving similar low-temperature operation through vacuum conditions and phase transitions
Solution Approach 2:
The patent changes the separation mechanism from membrane-based physical barrier to thermal-based phase transition under vacuum, operating at temperatures below 50°C through controlled evaporation and condensation processes, thereby avoiding high capital costs of membrane systems
3Manufacturing precision
If conventional distillation is used for ethanol separation, then ethanol purity is improved, but energy consumption increases
Solution Approach 1:
The patent implements continuous operation of the vacuum distillation system with continuous evaporation, separation, and condensation processes, maintaining steady-state operation that reduces energy fluctuations and improves overall energy efficiency compared to batch conventional distillation
Solution Approach 2:
The patent utilizes phase transitions (evaporation and condensation) under vacuum conditions to achieve ethanol separation and purification at low temperatures, where the latent heat of vaporization and condensation provides efficient heat transfer and energy utilization, reducing overall energy consumption while maintaining high ethanol purity
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 enables efficient ethanol recovery at low temperatures, maintaining microbial activity and reducing energy and operational costs, with approximately 40-50% power reduction and 60-70% cooling water reduction compared to conventional methods, while being applicable for fermentation technologies with temperature and residence time limitations.
Implementation Method 1
routing the compressed vapors obtained in step (c) to the falling film evaporator(E-1) for heat transfer from the compressed vapors to the demineralized water for generating a stripping steam
Implementation Method 2
wherein the compressed vapor is condensed to obtain a mixture of a condensed liquid and remaining vapors
Implementation Method 3
feeding the degassed and pre-heated fermented broth into a broth stripper vacuum column (C-1) for generating overhead vapors
Implementation Method 4
broth stripper column (vacuum distillation system)
Implementation Method 5
compressing the overhead vapors from the broth stripper column with a turbofan(K-1) to obtain compressed vapors at a pressure ranging from 160 to 200 mmHg
Implementation Method 6
routing demineralized water from bottom of the broth stripper column to a falling film evaporator(E 1)... for generating a stripping steam
Data Source
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AI summary
The present invention provides to a process for recovery of an organic compound (i.e. Ethanol, propanol, butanol, Acetone, iso-propyl alcohol) from a fermented broth which is produced from different fermentation technologies. The present invention particularly relates to an integrated process for ethanol separation from the fermentation broth using integrated vapor compressing unit (turbofans), evaporator (falling film) and a broth stripper column (vacuum distillation system). The process is operated under low temperature for the separation and recovery of the organic compound (particularly ethanol) from the fermented broth containing live microbes typically below or at 50°C to ensure the activity of the microbes in the broth recycle. Again, the activity of the microbes is further ensured by maintaining the residence time of the microbe containing broth outside the Fermentor is less than or equal to 10 minutes.