Investigation of simultaneous reaction of carbon monoxide and carbon dioxide with hydrogen on a commercial copper/zinc oxide catalyst

Abstract

The kinetics of low-pressure methanol synthesis from CO, CO 2 and H 2 on a commercial Cu/ZnO catalyst was investigated in a Berty-type reactor at low overall conversion to reduce the influence of chemical equilibria (reaction conditions: p = 3–5 MPa, T = 483–543 K). At constant H 2 partial pressure the ratio of CO to Co 2 was varied. The results show that the rate of methanol production depends strongly on the age of the catalyst and less strongly on the feed composition. The fresh catalyst gives a maximum rate with an H 2:CO:CO 2 ratio of 70:28:2, whereas the deactivated catalyst gives maximum rates if a synthesis gas with ratio 70:0:30 is used. The activation energy of methanol synthesis from CO 2 and H 2 is considerably lower than that from CO and H 2. The experimental results shed useful light on three contradictory kinetic equations published in the past decade.