Influence of process flowrates upon overall hydrogen yield in a ceramic heat-exchanger microreactor
Conference Paper
Overview
Overview
abstract
Our research group has developed a novel cartridge-based ceramic microreactor capable of creating 2-D heat integration schemes for efficiently coupling endothermic steam reforming and exothermic combustion of methanol liquid fuel within a single compact unit. Ceramic materials, with intermediate thermal conductivities, allow rapid radial heat conduction between exothermic and endothermic processes while limiting axial dissipation of reaction heat and heat losses to packaging, thus enabling hot-spot formation and self-insulating designs. In this study, we present the performance of a 25 channel (5 5) ceramic microreactor designed to carry out simultaneous methanol combustion (in a central channel) and methanol steam reforming (in the 9 adjacent channels), with the remaining outer 16 channels provide insulation via flow folding or sealing with stagnant gas. The reforming channels were packed with 0.3 g of CuO/ZnO/Al 2O 3 catalyst (supplied from BASF) while the combustion channel was packed with 0.14 g of Pt/Al 2O 3 (supplied from Sigma-Aldrich) located in the axial mid-section of the reactor. Over the range of flowrates investigated, the reactor was found capable of maintaining a self-insulating axial hot-spot at or near the center of the reactor, such that either end remained below 40oC and the outer (skin) temperature at the mid-section remained below 250C. Net hydrogen yields and thermal efficiencies in excess of 50% and 80%, respectively were observed.
