Simulation of isothermal fixed-bed reactor for ethanol dehydration to ethylene

Based on semi-empirical kinetic model of ethanol dehydration to ethylene on γ-Al₂O₃ catalyst, a one-dimensional mathematical model of isothermal fixed-bed reactor for ethanol dehydration to ethylene was established. Using industrial production data to verify the model, the deviations of calculated values of reactor outlet temperature, ethanol conversion and ethylene selectivity from the actual data of the plant were -1.65 K, -0.66% and 0.43%, respectively. Effects of heating medium temperature, feed space velocity and reactant concentrations in feed on axial temperature distribution in catalyst bed, conversions of ethanol, selectivity to ethylene were simulated. When heating medium temperature is controlled in range of 643-683 K, appropriate axial temperature distribution and better reaction results can be obtained. Appropriate feed hourly space velocity is about 0.6 h^-1. Higher hourly space will lead to lower conversion of ethanol. Higher content of ethanol in feed is favorable to ethylene selectivity and volume fraction of 95% is appropriate.