Compact string reactor for autothermal hydrogen production

Abstract

This study addresses the development of a compact reactor for oxidative steam-reforming of methanol (OSRM) to produce hydrogen in autothermal mode for fuel cells. The string reactor uses catalytically active brass wires with a diameter of 500 mm placed in parallel into a tube. The micro-channels in the reactor for gases are formed between the wires presenting hydrodynamics similar to the one in multi-channel micro-reactors. Due to the high thermal conductivity of brass, the heat generated during methanol oxidation at the reactor entrance is transferred to the zone of the endothermic steam-reforming. The catalysts are prepared by Al-alloy formation on the surface of the brass wires followed by the partial leaching of Al. The catalyst presents a porous layer with the morphology of Raney metals and the chemical composition consistent with the Cu/Zn/Al-mixed oxide. The catalyst surface was additionally modified by incorporating chromium leading to Cr/Cu-spinel. This decreases the degree of the reduction of copper oxide and sintering leading to a stable catalyst. The catalyst was tested in OSRM showing high activity and selectivity to carbon dioxide and hydrogen. The string reactor presents nearly isothermal profile since the temperatures gradient within the reactor length is about 3 K. Micro-structured string reactor presents a short start-up and a fast transient behavior showing a rapid temperature change when adjusting the oxygen amount introduced into the reactor. #

Experimental study and mechanistic kinetic modeling for selective production of hydrogen via catalytic steam reforming of methanol

“…(10)). Recently many researchers have also proposed the CO formation via rWGS (Agrell et al, 2001;Purnama et al, 2004;Reuse et al, 2004;Patel and Pant, 2006b;Horny et al, 2007) that uses the products of the reforming reaction i.e. H 2 and CO 2 .…”

Selective production of hydrogen via oxidative steam reforming of methanol using Cu–Zn–Ce–Al oxide catalysts

“…Recently, many researchers have also proposed the CO formation via rWGS reaction (Eq. (4)) (Agrell et al, 2001;Purnama et al, 2004;(Reuse et al, 2004;Horny et al, 2007).…”

Applications and Preparation Methods of Copper Chromite Catalysts: A Review

“…it does not require any external heating or cooling once the operational temperature is reached. For fast transient response, the methanol/ oxygen ratio can be varied as in the case of the Hot -Spot reformer [151]. OSRM is combination of steam reforming and partial oxidation processes.…”

“…Horny et al [151] developed a compact microstructured string reactor with catalytic brass wires for OSRM to produce hydrogen in auto-thermal mode for fuel cells. CuCr2O4 catalyst used in OSRM showed high activity, and selectivity to carbon dioxide and hydrogen.…”