Evaporative Distillation for Ethanol Production Steam Reduction
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Solution Overview
Problem
Conventional ethanol production processes require high steam consumption during distillation, which is economically inefficient, especially when the ethanol concentration in the fermented wash is low.
Innovation Solution
The process involves preheating a fermented wash and subjecting it to degasifying and evaporative distillation steps, with energy integration between columns to minimize steam usage, allowing for efficient evaporation and condensation of ethanol vapors, thereby reducing steam consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If conventional distillation is used to produce ethanol from fermented wash, then ethanol can be obtained, but steam consumption is high (2-3 kg per litre of ethanol)
Solution Approach 1:
The patent applies preliminary action by performing evaporation of fermented wash before distillation. The process includes preheating the fermented wash and subjecting it to evaporation in an evaporator to generate a concentrated ethanol stream, which then undergoes distillation. This preliminary concentration step reduces the load on the distillation column and decreases steam consumption during the actual distillation process.
Solution Approach 2:
The patent changes the physical parameters of the fermented wash by controlling evaporation at specific temperatures. The evaporator operates to concentrate ethanol without complete vaporization, and the process maintains temperature control to optimize energy efficiency. This parameter change approach allows concentration of ethanol before distillation, reducing overall steam requirements.
2Quantity of substance
If evaporation distillation is used to reduce steam consumption, then steam usage decreases to 1.3 kg per litre, but process complexity increases with multiple columns and energy integration
Solution Approach 1:
The patent merges multiple functions into an integrated process system. The evaporator and distillation column are energy-integrated, where vapors from the distillation column are condensed and used to preheat the fermented wash before evaporation. This merging of heating functions reduces external steam requirements and optimizes energy utilization within the system.
Solution Approach 2:
The condenser serves multiple functions: it condenses vapors from the distillation column, generates preheating steam for the evaporator, and maintains system pressure balance. This multi-functionality reduces the need for separate heating systems and external steam inputs, thereby reducing overall steam consumption despite the added process integration.
3Quantity of substance
If evaporation is performed before distillation, then steam consumption is reduced, but energy integration and heat exchange requirements increase
Solution Approach 1:
The system implements feedback through heat integration, where the output from the distillation column (hot vapors) is fed back to preheat the input stream for the evaporator. This feedback loop optimizes energy utilization by recovering heat that would otherwise be wasted, reducing the net external energy input required for the process.
Solution Approach 2:
The process system serves itself by using its own internal heat sources to provide necessary heating. The distillation column vapors self-generate the preheating steam needed for the evaporator, and the condensed vapors self-condense to provide heating medium. This self-service approach minimizes external steam requirements and reduces overall energy input.
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 significantly reduces steam consumption per liter of ethanol produced, achieving an ethanol concentration of up to 95% with only 1.3 kilograms of steam per liter, compared to the typical 2-3 kilograms in conventional methods.
Implementation Method 1
subjecting said second stream to a first evaporator forming a second vapour stream and a depleted ethanol stream
Implementation Method 2
The evaporator is heat integrated with a mash column downstream
Implementation Method 3
condensing said second vapour stream using a second evaporator forming a third stream and collecting it in said collection tank forming said high ethanol stream
Implementation Method 4
The evaporator is heat integrated with a mash column downstream
Implementation Method 5
subjecting said depleted ethanol stream to a distillation column forming a third vapour stream and a spent stream
Data Source
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AI summary
A process for producing ethanol by evaporative distillation is disclosed, wherein fermented wash is first evaporated in an evaporator to generate a concentrated ethanol stream. The remaining part of said wash is then further purified in a mash column to isolate remaining ethanol from said wash. In this process as a large part of fermented wash is removed in evaporation process, the load on the mash column is significantly less and hence small size of mash column is required.