Effect of precursor on the performance of alumina for the dehydration of methanol to dimethyl ether

Dimethyl ether (DME) is amongst one of the most promising alternative, renewable and clean fuels being considered as a future energy carrier. In this study, the comparative catalytic performance of gamma-Al2O3 prepared from two common precursors (aluminum nitrate (AN) and aluminum chloride (AC)) is presented. The impact of calcination temperature was evaluated in order to optimize both the precursor and pre-treatment conditions for the production of DME from methanol in a fixed bed reactor. The catalysts were characterized by TGA, XRD, BET and TPD-pyridine. Under reaction conditions where the temperature ranged from 180 degrees C to 300 degrees C with a WHSV = 12.1 h(-1) it was found that all the catalysts prepared from AN(eta-Al2O3) showed higher activity, at all calcination temperatures, than those prepared from AC(gamma-Al2O3). In this study the optimum catalyst was produced from AN and calcined at 550 degrees C. This catalyst showed a high degree of stability and had double the activity of the commercial gamma-Al2O3 or 87% of the activity of commercial ZSM-5(80) at 250 degrees C. (C) 2012 Published by Elsevier B.V.