Development of a microchannel reactor concerning steam reforming of methanol

To develop a portable power device using fuel cell technology, the miniaturization of the hydrogen production unit is indispensable. In this paper, preparation of a microchannel reactor concerning steam reforming of methanol (SRM) has been investigated by optimizing the parameters of diffusion bonding and the composition of catalyst coatings. The results show the microchannel reactor can be sealed successfully by diffusion bonding at the optimized parameters (900 degrees C, 20 MPa, 1 h). The most active and selective catalyst coating is Cu50/Zn50 [Ce5] (Cu/Zn/Ce=50/50/5, molar). It has been found that CeO2, has an important influence on improving catalytic activity, decreasing the outlet CO concentration, and strengthening the stability. Based on the characterization of catalyst coatings, it can be attributed to the increase in copper area and to the change in oxidation state of copper that results in the synergetic effect of Cu-0 and Cu+. In addition, the effects of reaction temperature, space velocity, molar ratio of methanol to water, and reaction time were also investigated in the developed microchannel reactor with the Cu50/Zn50 [Ce5]. The results show that the microchannel reactor can generate enough hydrogen for a power output of 11 W. (c) 2005 Elsevier B.V. All rights reserved.