| In methanol synthesis using a copper-zinc oxide catalyst, the reactant mixture of CO, CO(,2) and H(,2) can under go three reactions: CO + 2 H(,2) = CH(,3)OH, CO(,2) + 3 H(,2) = CH(,3)OH + H(,2)O and the water-gas shift reaction. This research addressed the questions of whether methanol is produced from CO or CO(,2), and what are the roles played by CO(,2) and H(,2)O.; The initial rates of methanol production were measured in a batch reactor at 195 to 225(DEGREES)C and 17 atmosphere. All the measurements were made in the absence of mass and heat transport influence. The rates were found to increase with increasing CO(,2)/CO ratio in the feed, and were suppressed by the presence of water. From the C('1 8)O(,2) isotope experiments, water was shown to suppress the production of C('18)O and methanol -('18)O but not methanol -('16)O. There are at least four parallel reactions on the catalyst: CO-CO(,2) exchange which was the fastest, CO hydrogenation, CO(,2) hydrogenation, and water-gas shift. Exchange of lattice oxygen with oxygen in CO(,2) also took place. There was no evidence for the production of methanol from the reaction of CO and water.; A relaxation method employing nonequilibrium thermodynamics for data analysis was applied to determine the equilibrium exchange rates of the three reactions in methanol synthesis. The magnitudes of these exchange rates were of the order of the initial rates of methanol production measured under similar conditions. |
