Synthetic fuels and chemicals production from biomass synthesis gas

Experimental research on the synthesis of dimethyl ether (DME), ethylene glycol (EG), methyl glycolate (MG) from syngas, produced by biomass gasification and catalytic reforming, was carried out. The improved two step process, composed of methanol synthesis and methanol dehydration in a fixed-bed reactor, was employed for the direct DME synthesis. It shows that methanol synthesis catalyst in top stage is more sensitive to the temperature vibration than that of dehydration catalyst in the bottom stage. The process for EG and MG production from biomass-derived syngas involves two steps, the coupling of CO with nitrite esters to dimethyl oxalate (DMO) and the hydrogenation of DMO to ethanol, EG and MG. It reveals that low reaction temperature and H₂/DMO molar ratio and high gas hourly space velocity (GHSV) facilitate to the MG production while the opposite reaction conditions would lead to improve the ethanol selectivity, and the moderate reaction conditions are beneficial to convert DMO to EG.