Optimization Of Ethanol-ether Biofuels Mixtures Separation Process

A process conbining ethanol dehydration and ethanol-ethyl tert butyl ether (ETBE) separation was proposed on the basis of previous ETBE preparation process and the multiple azeotropic property of water-ethanol-ETBE system in this paper. And the phase equilibrium, distillation, extraction and total process were studied. It showed that UNIQUAC method was appropriate for the simulation of phase equilibrium. Distillation and extraction column were optimized by Aspen Plus, and the distillation simulation results were consistent with the experiment. Then dehydrated ethanol as water content below 0.5 wt% and pure ETBE as 99 wt% content above could be obtained through the new process. Compred with the typical processes, energy consumption in this process could be reduced by more than 30%, with 1 Kg ETBE produced as well as 0.94 Kg 92.5 wt% ethanol. Finally, the new process utilizing water and dilute ethanol solution as the extractants was put forward, and 0.24 Kg water was saved per unit of ETBE with 11.93 KJ per unit of ethanol recovery.