An accurate one-dimensional, heterogeneous model taking account of axial dispersion and heat transferto the reactor wall, and heat conduction through the reactor wall for methanol synthesis in a bench scale reactorunder periodic reversal of flow direction is presented. Adjustable parameters in this model are the effectivenessfactors for each of the three reactions occurring in the synthesis and a factor for the bed to wall heat transfercoefficient correlation. Experimental data were used to evaluate these parameters and reasonable values of theseparameters were obtained. The model was found to closely predict the reactor performance under a wide range ofoperating conditions, such as carbon oxide concentrations, volumetric flow rate, and cyclic period.