Direct synthesis of ethanol from dimethyl ether and syngas over combined H-Mordenite and Cu/ZnO catalysts

Ethanol was directly synthesized from dimethyl ether (DME) and syngas with the combined H-Mordenite and Cu/ZnO catalysts that were separately loaded in a dual-catalyst bed reactor. Methyl acetate (MA) was formed by DME carbonylation over the H-Mordenite catalyst. Thereafter, ethanol and methanol were produced by MA hydrogenation over the Cu/ZnO catalyst. With the reactant gas containing 1.0 % DME, the optimized temperature for the reaction was at 493 K to reach 100 % conversion. In the products, the yield of methanol and ethanol could reach 46.3 % and 42.2 %, respectively, with a small amount of MA, ethyl acetate, and CO₂. This process is environmentally friendly as the main byproduct methanol can be recycled to DME by a dehydration reaction. In contrast, for the physically mixed catalysts, the low conversion of DME and high selectivity of methanol were observed.Do or dual not: A dual-catalyst bed reactor loaded separately with the Cu/ZnO and H-Mordenite catalyst is employed to directly synthesize ethanol from dimethyl ether (DME) and syngas. The yield of ethanol and the main byproduct methanol are 42.2 % and 46.3 %, respectively. The latter can be further recycled to DME realizing an environmentally friendly process.