Ethanol to high-octane hydrocarbons using HZSM-5 as catalyst

Abstract

Dehydration and oligomerization of ethanol to hydrocarbons was studied using a packed-bed reactor over HZSM-5 (SiO2/Al2O3=280 mol/mol) zeolite as catalyst. Nine experiments were performed at different temperature and weight hourly space velocity (WHSV) conditions. The experiments were conducted in three levels for both variables (T: 300, 350, and 410 °C) and (WHSV: 1.3, 3.7, and 7.9 h–1). For all the experiments, ethanol was dehydrated to ethylene; however, oligomerization only occurred at WHSV=1.3 h-1, where the yields to liquid hydrocarbons were 15, 25, and 10% at 300, 350, and 410 °C, respectively. The liquid hydrocarbon products were analyzed by copper metal corrosion, gum content, octane number, Reid vapor pressure, gas chromatography, and fractional distillation. The octane number was about 95 in all cases, higher than Ecuador premium gasoline octane number (92). These laboratory-scale findings provide good insights on the ethanol-to-gasoline approach that could be scaled up to the industry.