The model, developed by Senkam et al. did not correlate the experimentally measured carbon monoxide mole fraction profiles in an annular tube-wall methanation reactor (outer tube 2.0 in. dia coated on the inside with Raney nickel catalyst and solid inner tube 1.5 in. dia) at 300 psig and 385/sup 0/C, with a 3 : 1 hydrogen/carbon monoxide feed at a flow rate of 450 std cu ft/hr. Results showed that the reaction is not diffusion-limited and that kinetic resistance must be included. By using a model for methanation reactors with thermally sprayed catalyst which includes both diffusion and kinetic resistance, e.g., that of Lee and Feldkirchner (Abstract No. S3-528), a remarkably good agreement with experimental data was obtained. The model predicted a CO conversion of 93.7% compared with the measured 91.3%.