A plate-type auto-thermal reforming (ATR) reactor with both hydrogen permeable and oxygen permeable membranes has unique characteristics of mass transfer and heat transfer, which have a big effect on the hydrogen production and hydrogen recovery. In order to study the special mass and heat transfer inside the two-membrane ATR reactor, a 2-D reactor model was developed, and a reactor simulation was carried out. In the single-stage two-membrane ATR reactor, the large gradients of temperature and hydrogen concentration indicate the limitation of mass transfer and heat transfer. To improve the mass and heat transfer, multistage reactors are suggested. The simulation results show that the multistage reactors have better mass and heat transfer, a lower rate of oxygen consumption, higher operating temperatures of the H-2 membrane, and a larger driving force for hydrogen permeation, and hence can produce more than three times the amount of pure hydrogen than the single-stage reactor. (c) 2007 Elsevier Ltd. All rights reserved.