Sensitivity analysis of ethanol production process using Aspen Plus

Abstract

The responsesof liquid ETBE mole fraction towards ethanol volumetric flow rate, butene volumetric flow rate, reflux ratio and reboiler duty have been investigated in this work using sensitivityanalysisof an etherification process carried out in a reactive packed distillation column. The process was modeled as an equilibrium type taking place in liquid phase with the aid of Aspen PLUS. The column used had 19 segments including the condenser and the reboiler. The results obtained from the analysis showed that the responses of liquid ETBE mole fraction towards ethanol flow rate were obtained without any “status error”, but those towards the other parameters were with “status errors”. Simulating the process with the optimum parameters obtainedfrom the analyses, the values of butene flow rate, reflux ratio and reboiler duty could not reproduce the maximum liquid ETBE mole fractions given by the sensitivity analyses, but that of ethanol volumetric flow rate could approximately reproduce the result. Therefore, the importance of volumetric flow rate of ethanol in influencing the purity of liquid ETBE obtained from the etherification process carried out in the reactive packed distillation column as well as the necessities of sensitivity analyses to chemical processes has been demonstrated.