화학공학소재연구정보센터
Chemical Engineering Science, Vol.49, No.2, 209-221, 1994
Kinetics of the Synthesis of Methanol from Co+h2 and Co+co2+h2 over Copper-Based Amorphous Catalysts
The catalytic behaviour of amorphous alloys (prepared by spark-erosion) for the synthesis of methanol from mixtures of H-2 + CO and H-2 + CO + CO2 was studied at 10 bar and 200, 225 and 250-degrees-C. Measurements of the rates of methanol production from feeds containing from 0 to 20 mol% CO2, at a constant H-2 : CO ratio, quite surprisingly revealed that the presence of carbon dioxide resulted in a large increase in the rate of production of methanol. For a catalyst of composition Cu70Zn30, maximum rates were observed at 2 mol% CO2, whereas for a Cu70Zr30 catalyst, the activity increased with increasing CO2 contents, up to 10 mol%. These results suggest that with these catalysts the hydrogenation of carbon dioxide is significantly faster than that of carbon monoxide. Two models for the kinetics of methanol production have been developed from mechanistic considerations reported recently in the literature. It turns out that it is best to describe the rate of formation of methanol from H-2 + CO and H-2 + CO + CO2 as a combination of these two models; this corresponds to a mechanism whereby CO2 is the source of carbon for methanol from a mixture of H-2 + CO + CO2.