Ethylene Formation from Ethanol Dehydration Using ZSM-5 Catalyst.

Catalysts prepared for ethanol dehydration in a fixed-bed reactor acted as strong active acidic catalysts under reaction conditions at lower temperatures. Experimental conditions including the catalyst type [active aluminum oxide (γ-AlO) and ZSM-5 zeolite catalyst modified using two-stage through dealumination or desilication and by using the impregnation method with phosphorous and lanthanum], weight hourly space velocity (WHSV), ethanol concentration, and reaction temperature were investigated to obtain optimal reaction conditions. The catalysts were characterized using the Brunauer-Emmett-Teller method, temperature-programmed desorption of ammonia gas, thermogravimetric analysis, X-ray photoelectron spectroscopy, and X-ray diffraction. The results revealed that the ethylene yield and selectivity were 98.5 and 100%, respectively, for the ZSM-5 zeolite catalyst modified through dealumination at a temperature of 220 °C and WHSV of 2.5 h when the ethanol concentration was 95%. The ethylene yield and selectivity were 94.3 and 94.4%, respectively, for the ZSM-5 zeolite catalyst modified using phosphorous at a temperature of 240 °C and WHSV of 1.5 h when the ethanol concentration was 20%. Both of these catalysts were the most favorable among all prepared catalysts.