The recovery of H-2 from H2S is an economical alternative to the Claus process in petroleum and minerals processing industries. Previous studies [React. Kinet. Catal. Lett. 62 (1997) 55; Catal. Lett. 37 (1996) 167] have demonstrated that catalytic decomposition of H2S over bimetallic sulfide can proceed at relatively higher rates than over mono-metallic systems due to chemical synergism although conversions are still thermodynamically limited. In the present study, the performance of a catalytic membrane reactor containing a packed bed of Ru-Mo sulfide catalyst has been investigated with a view to improving H-2 yield beyond the equilibrium ceiling. A system of differential equations describing the non-isothermal reactor model has been solved To examine the effect ai important hydrodynamic and transport properties an conversion. The results were obtained using a Pt-coated Nb membrane tube as the catalytic reactor enclosed in a quartz shell cylinder. Reynolds number for shell and tube side (Re-s and Re-t) as well as the modified wall Peclet number, Pe(m), dramatically affect H2S conversions. Membrane reactor conversion rose monotonically with axial distance exceeding the equilibrium conversion by as much as right times under some conditions. (C) 2000 Elsevier Science B.V. All rights reserved.