A comprehensive two-dimensional (2D) reactor model has been developed to simulate the flow behavior in a fixed-bed reactor for preparing olefins from methanol. An exponent-function kinetic model based on a lumped-species reaction scheme has been incorporated to a commercial computational fluid dynamics (CFD) code Fluent by user defined functions for simulating the methanol to olefins (MTO) reaction. The approach and model have been validated with the actual data collected from open reports where the above kinetic model is adopted. Furthermore, the coke deposition and the component distributions during the MTO reaction over SAPO-34 have been simulated in the fixed bed reactor as a function of feed temperature (673-753 K), space velocity (57-113g.(gcat.h)(-1)) and feed composition. In addition, the optimizational simulation has also been done. The simulation results show that the methanol conversion and the catalytic deactivation are closely related to each other and are obviously influenced by operation conditions studied in this work. (C) 2012 Elsevier B.V. All rights reserved.