The catalytic activity of Co/kaolinite catalyst for dimethyl ether synthesis via methanol dehydration

Abstract

The production of dimethyl ether (DME), renewable fuel, using dehydration of methanol over Co supported on kaolinite catalysts was investigated. In this study, kaolinite was modified by impregnation of the various percentage of Co (5%Co/KN, 10%Co/KN, and 15%Co/KN) to improve the activity of the catalyst. The prepared catalysts were characterized by nitrogen gas adsorption using the Brunauer–Emmett–Teller (BET) method, and the X-ray diffractometer (XRD). The thermogravimetric analysis (TGA) was used to analyze of coke formation on spent catalysts. The catalytic performances of catalysts were tested in a fixed-bed reactor at atmospheric pressure at the temperature range of 250–350 °C with a fixed weight hourly space velocity (WHSV) of 2.054 h−1. It was found that 5%Co/kaolinite showed the highest methanol conversion of 81.7% among the Co/KN catalysts; however, the DME selectivity was less than 80%. The presence of Co gave the less formation of coke on used catalysts indicating that the Co/KN catalyst had more stable than unmodified kaolinite. The 15%Co/KN is an active, selective, and durable catalyst for DME production at the temperature of 300 °C.