Ultra-compact microstructured methane steam reformer with integrated Palladium membrane for on-site production of pure hydrogen: Experimental demonstration

Abstract A novel metal-based modular microstructured reactor with integrated Pd membrane for hydrogen production by methane steam reforming is presented. Thin Pd foils with a thickness of 12.5 μm were leak-tight integrated with laser welding between microstructured plates. The laser-welded membrane modules showed ideal H 2 /N 2 permselectivities between 16,000 and 1000 at 773 K and 6 bar retentate pressure. An additional metal microsieve support coated with an YSZ diffusion barrier layer (DBL) facilitated the operation at temperatures up to 873 K and pressures up to 20 bar pressure difference. The membrane permeability in this configuration is expressed with Q  = 1.58E-07*exp(−1460.2/T) mol/(msPa 0.5 ). In the first proof-of-concept reaction experiments the influence of W / F ratio ( 0.33 – 1 . 32 g Cat h / mol CH 4 ) , S / C ratio (3 and 4), temperature (773 and 823 K) and retentate/reformate pressure (6–12 bar) was studied. Methane conversion of 87% and a hydrogen recovery of 92% were obtained at a W / F ratio of 0.33 g Cat h / mol CH 4 , corresponding to a GHSV of 29,000 h −1 , a temperature of 823 K and a feed pressure of 12 bar without the use of sweep gas. The microstructured membrane reactor showed a promising performance for the production of pure hydrogen in a very compact and modular system.