Effect of Phosphorus Impregnation on γ-Al2O3 for Methanol Dehydration to Dimethyl Ether

Dimethyl ether has gained great attention by Indonesian Government since it will be used for the substitution for liquid petroleum gas. This work was aimed to study the effect of phosphorus addition on gamma-Al2O3 catalyst for methanol dehydration to DME synthesis. The catalysts were prepared using sonication-assisted impregnation. The modified catalysts were characterized (XRD, BET, and NH3-TPR analysis), and their activity was tested in bench scale reactor. The results showed that the 5%P/gamma-Al2O3 catalyst had medium acidity which was good for dehydration of methanol to DME. The surface area, pore volume, and pore diameter were measured as 132 m(2)/g, 0.42 mL/g, and 127 angstrom, respectively. The activity test was carried out at 240-280 degrees C, atmospheric pressure, and GHSV 2,142 h(-1). The 5%P/gamma-Al2O3 catalyst exhibited good performances at a temperature of 240 degrees C with 42% of methanol conversion, 18% of yield of DME, and 75% of selectivity of DME. Methanol dehydration using modified 5% P/gamma-Al2O3 did not produceH(2) by-products and other compounds whichwere produced during methanol dehydration with unmodified gamma-Al2O3.