The transient behaviour of an adiabatic fixed-bed methanator has been studied using the.hydrogenation of mixtures of CO and CO, at concentrations up to 2.7 vol. % carbon oxide in hydrogen as the test reactions. Responses to disturbances in feed conditions were studied by measuring the axial temperature profile as a function of time. The results show that the dynamic behaviour of the reactor is complicated by the inhibition by CO of fhe methanation of co,.
The agreement between theory and experiment was again quite satisfactory: the quasi-homogeneous plug flow model which applied to experiments using biiy mixtures of hydrogen and a car& oxide applies to the data obtained with mixtures of CO, CO, and hydrogen, provided that the successive hydrogenation of CO and CO, is taken into account. However, it is improbable that the quasi-homogeneous model can be applied to industrial methanation, when the higher temperatures and consequent faster rates of methanation are likely to cause heat and mass transfer limitations. Nevertheless, there is no doubt that response times of but a few seconds must be expected in industrial methanation.