Abstract: The construction with an adiabatic and tube shell catalytic bed has been proposed for large capacity methanol converter. Two dimensional mathematical model of the converter was developed with hydrogenation of CO and CO 2 as the independent reactions and methanol and CO 2 as the key components, and solved by orthogonal collocation method to obtain axial and radial profiles of temperature and the gaseous concentration in the catalytic bed. The effect of the inlet temperature and the operating pressure on the temperature distribution in the bed and methanol yield was simulated. In the middle and later period the same productivity can be obtained by increasing temperature of boiling water and operating pressure slightly. The predicted values of temperature distribution in the bed and yield was coincident with the practical data very well.