MANUFACTURE OF ETHANOL FROM RECTIFIED SPIRIT
There are two basic processes used for the manufacture of anhydrous ethanol from rectified spirit namely molecular sieve and azeotropic distillation. Both the processes are detailed below.
MOLECULAB SIEVE
A - Design Basis
The factors used to establish the design basis for the vapor phase molecular sieve dehydration system for fuel grade ethanol, are as follows.
Anhydrous Alcohol Production, liter / day 10,000
Product Quality % V/V 99.8 min
Feedstock Rectified spirit
Feedstock Quality, RS 94.68 % v/v, min
B – AZEOTROPIC DISTILLATION
Process Description
Two column azeotropic distillation system is proposed for dehydrating ethanol cyclohexane or benzene can be used as an entrained for the purpose. The total consists of feed pumps preheated, dehydration column, recovery column, condenser, reboiler, decanter, intermediate tanks transfer pump
Highlights of the Technology
- This unit allows the production of 99.95% volume anhydrous alcohol from 96% volume rectified alcohol or from 92% volume raw alcohol for fuel ethanol production
- The process implies a distillation with cyclohexane. The ternary azeotropic mixture, which is formed at the top of dehydration column, allows the removal of water and thus the dehydration of alcohol of alcohol. The azeotropic mixture is heterogeneous and the "heavy" phase, which is high in water content, is extracted by decantation. The regeneration column allows water extraction from the "heavy" phase and cyclohexane recycling.
Advantages
- Minimum Labour
- Stable Operation
- Near theoretical recovery
- Steam Consumption minimized by multi-stage preheating to permit substantial heat recovery and reuse.
- An advanced control system, developed through years of experience, to provide sustained, stable, automatic operation.
- Consistent excellent product quality maintained.
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