The present work deals with a study coupling experiments and modeling of catalytic steam gasification of municipal solid waste (MSW) for producing hydrogen-rich gas or syngas (H(2) + CO) with calcined dolomite as a catalyst in a bench-scale downstream fixed bed reactor. The influence of steam to MSW ratios (S/M) on gas production and composition was studied at 900 degrees C over the S/M range of 0.39-1.04, for weight hourly space velocity (WHSV) in the range of 1.22-1.51 h(-1). over the ranges of experimental conditions examined, calcined dolomite revealed better catalytic performance at the presence of steam. H(2) and CO(2) contents increased with S/M increasing, while CO and CH(4) contents decreased sharply, the contents of CH(4), C(2)H(4) and C(2)H(6) were relatively small, and the influence of S/M was insignificant. The highest H(2) content of 53.22 mol%, the highest H(2) yield of 42.98 mol H(2)/kg MSW, and the highest H(2) potential yield of 59.83 mol H(2)/kg MSW were achieved at the highest S/M level of 1.04. Furthermore, there was a good agreement between the experimental gas composition and that corresponding to thermodynamic equilibrium data calculated using GasEq model. Consequently, a kinetic model was proposed for describing the variation of H(2) yield and carbon conversion efficiency with S/M during the catalytic steam gasification of MSW. The kinetic model revealed a good performance between experimental results and the kinetic model. (C) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.