The coupling performance of nano-CaO carbonation with the steam methane reforming (SMR) during reactive sorption enhanced reforming process (ReSER) for hydrogen production was studied by simulation and experimental evaluation. A two-dimensional axial symmetric pseudo-homogeneous mathematic model was established based on nano-CaO carbonation kinetics with the Boltzmann equation style and SMR reaction kinetics. The coupling performance was studied by varying carbonation rate constant (k(carb)) and the maximum carbonation conversion (X-max) in the model. The mathematic model was numerically solved by the COMSOL Multiphysics software and experimentally evaluated using commercial nano-CaO as the CO2 adsorbent. An average relative deviation of 3.86% of CH4 conversion was obtained between the simulated and experimental results. The simulation results indicated the conversion of the CH4 was improved from 88% to 95.3% by increasing k(carb) from 1.6 s(-1) to 5.74 s(-1) and the period of pre-breakthrough time could be extended from 2 min to 20 min by increasing X-max from 0.3 to 0.9. CH4 conversion of maximum 94.1% when reaction was under 650 degrees C and 1 bar, the highest molar fraction of H-2 of 99.7% when reaction at 600 degrees C and 1 bar, and the maximum enhancement factor of 45.4% was obtained at 576.3 degrees C, 2.8 bar. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.