Chemical equilibria in methanol synthesis

The chemical equilibria of the methanol reaction and the water—gas shift reaction, starting from carbon monoxide, carbon dioxide and hydrogen, were studied in a fixed-bed catalytic reactor at P = 10–80 bar and T = 200–270°C. It was found that the chemical equilibria could be described very well by thermochemical data based on ideal gas behaviour in combination with a correction for the non-ideality of the gas mixture as predicted by the Soave—Redlich—Kwong equation of state. This correction for non-ideality results in significantly better agreement with experimental data than a correction based on the original Redlich—Kwong equation of state, the Peng—Robinson equation of state, the virial equation truncated after the second virial coefficient, Lewis and Randall's rule, or not correcting at all for non-ideality, thus assuming ideal gas behaviour.