Comparative Study of Fluid Package on Extractive Distillation of Ethanol-water Mixture Using Pure Glycerol and Ethylene Glycol as Extracting Solvents

Abstract

The comparative study of Peng Robinson Strygek Vera (PRSV) and Non-Random Two Liquid (NRTL) fluid packages on the extractive distillation of ethanol-water mixture was done using pure glycerol and ethylene glycol as extracting agents. The process was simulated using HYSYS V. 8.4. Pure glycerol and ethylene glycol-glycerol mixture were used as separating agents. The results showed the highest molar composition of ethanol in the distillate at the solvent feed rate of 80 kmol/hr when pure glycerol was used with NRTL fluid package. With the PRSV fluid package the highest ethanol in the distillate was obtained at pure glycerol feed rate of 50 kmol/hr. The ethanol fraction in the distillate was decreasing with increasing ethylene glycol and decreasing glycerol in the ethylene glycol-glycerol mixture. The comparative study of the base case and alternative designs showed high ethanol composition in distillate in the range of 99.46 - 99.96% and 99.96 - 99.67% for NRTL and PRSV fluid package, respectively. It was concluded from the study that the PRSV fluid package could save cost of operation because of lower solvent requirement and energy consumption in the reboiler for both the base case and alternative designs.