Process Design Of Pressure Swing Distillation For Ethanol-Water Separation System

Abstract

Nowadays, Bio ethanol has usage demand in all around the world in replacement for petroleum. So, it is require to separation of ethanol-water mixture after alcohol produce from the fermentation for producing the bio ethanol. So that, Distillation used for separation of ethanol-water mixture. However this distillation process is a well known process as an energy- consuming process because of ethanol and water form an azeotropic mixture. It is impossible to recover pure ethanol from simple distillation due to reason of azeotrope. The most commonly methods used for separation of ethanol-water mixture are currently extractive distillation, pressure swing distillation, pressure swing adsorption of water on molecular sieves & pervaporation. Property package is useful for a represent the behavior of level and phase equilibrium of mixture and pure compound system. Thermodynamic models help in optimization of equipment, Operation and process in process simulator. It is carried out because of optimization involves both simulation accuracy aspects and economic. So that, simulation of ethanol-water mixture separation by distillation in process simulator it required a thermodynamic model for generating an accurate result and also to optimization the process with optimum results. Designing for dehydration of ethanol-water by using distillation would require vapor-liquid equilibrium (VLE) data at vacuum as well as appropriate azeotropic data to ensure the techno economical feasibility of the system. Ethanol is commonly use as alcohol or spirits. Bio ethanol may also be used as raw material for the production of different chemicals, thus falling a full renewable chemical industry. Bio ethanol is production from the fermentation of sugars obtain from biomass. Bio ethanol raw material can contain either sucrose. Ethanol-water mixture is separated by distillation so that thermodynamic property are important for consideration, we found the most suitable thermodynamic model for ethanol-water system which is used in process simulator for simulate process flow sheet in process simulator (Aspen HYSYS). The PSD process is important to break the azeotrope without using any entrainer / solvents. The PSD is effective when the azeotropic composition is a pressure sensitive. Once fluid package was decided next was to simulate the operation and the to optimize considering in mind economic cost as required product purity. Finally Heat exchangers were designed for the the cases for which literature review was carried out for selection of type of exchanger and then designing was carried out using manual calculation as well HTRI software.