The cell model was applied to simulate the mass transfer in a swarm of spherical solid particles under intermediate Reynolds numbers based on the numerically resolved flow field in the cell. Simulations were conducted in the range of 1 less than or equal to Re less than or equal to 500, 0.4 less than or equal to epsilon less than or equal to 0.9 and 1 less than or equal to Pe less than or equal to 3000. Numerical simulation results suggest the significant effect of swarm voidage epsilon and the Peclet number Pe, and indicate that the conventional definition of the mass transfer factor as a simple function of Re(1 - epsilon), as found in empirical correlations in the literature, fails to account for the effects of Pe and the voidage. Comparison of the simulation results for the mass transfer factor with two recommended correlations is reasonable and the deviation from the correlations seems to increase as Re/(1 - epsilon)>100. This suggests the need for further improvement on cell models for the high Reynolds number range. (C) 2003 Elsevier B.V. All rights reserved.