This work describes the research aimed at developing mathematical model for predicting the performance of the monolith reactor. Two heterogeneous models were applied to describe a single channel of the reactor. Comparison between the mass transfer coefficients, obtained using the model with ID description of the gas phase and 2D description of the solid phase and a complete 2D model (2D description of both gas and solid phase) was made and discussed. The proposed models were verified by comparing the experimental data with theoretical predictions. Particular emphasis was put on the interphase mass transfer. (C) 2004 Elsevier B.V. All rights reserved.