Direct synthesis of dimethyl ether from syngas over copper catalysts prepared using the sol-gel method

摘要

Dimethyl ether (DME) is slightly expensive chemical now, because DME is manufactured by dehydration of methanol. However, DME is expected as a clean fuel for the 21st century, from the reasons that DME does not contain poisonous substances, and DME burns without particulate matters (PM) [1]. DME will be used as substitutes of liquefied petroleum gas (LPG) and diesel oil, and will be used for hydrogen carrier. Therefore, demand of DME will increase rapidly, and it is necessary to mass-produce DME economically. There is a method, direct synthesis of DME, that DME is synthesized directly from syngas (hydrogen and carbon monoxide), not synthesized by dehydration of methanol. Excellent catalysts for the direct synthesis are necessary. In this study, copper alumina catalysts prepared using the sol-gel method that is appropriate for DME steam reforming [2, 3] are applied for direct DME synthesis (3H2 + 3CO → CH3OCH3 + 2CO2) that is a kind of reverse reaction of DME steam reforming (CH3OCH3 + 3H2O → 3H2 + 2CO2).