Conversion of Bioethanol and Ethylene to Drop-in Fuel Hydrocarbons Under Supercritical Conditions

The conversion of bioethanol to hydrocarbons is a promising technology for the production of drop-in fuels from lignocellulosic biomass. This process is heterogeneously catalyzed by HZSM-5 and it takes place in two steps: 1) dehydration of ethanol to ethylene, 2) oligomerization of ethylene to various lengths of hydrocarbon molecules. To characterize these steps, we will present experimental results which include supercritical conditions. Our results indicate that supercritical conditions decrease selectivity to aromatic hydrocarbons, which is an advantage from an emissions perspective. This, in turn, is expected to reduce coke formation and improve catalyst lifetime. In this talk, we will report results from: 1) the conversion of ethanol to hydrocarbons, 2) the oligomerization of ethylene to drop-in fuel molecules. Our goal is to understand the role of supercritical conditions and develop kinetic models for this process to predict the yields of permanent gases, linear/branched paraffins, olefins, naphthenes, aromatics, and solid char.