MODELING OF A MEMBRANE MICRO‘CHANNEL REACTOR FOR A WATER GAS SHIFT REACTION

Abstract

Micro-channel reactor offer unique possibilities for temperature control of chemical reaction due to the strong coupling of channel and wall temperature. For the reformation of hydrocarbons for fuel-cell applications a low CO conversion of the product gas is desired. For every gas composition arising during the reaction process an optimum temperatures exists at which the reaction rate is highest. We have demonstrate that this optimum temperature profile to a good approximation can be achieved in a single step water gas shift reactor by controlling the temperature via . cooling gas flowing in parallel to the reformate. Here, we have discusses the development of an integrated reaction and heat exchange approach to micro-channel reactor design that enhances the reaction yields. We detail the formulation of one-dimensional models for micro-channel reactor with and without heat conduction through the wall-channel and apply these models to study WGS reaction. The parametric study investigated the sensitivities of design parameters of the micro-channel reactor. Results from study are presented and discussed, and the optimized operating parameters are identified for the both case of micro-channel reactor. We also detail the formulation of one-dimensional models for membrane micro-channel reactor with the consideration of heat conduction through the wall-channel and apply these models to WGS reaction. We also considered the case of membrane micro-channel reactor without the heat conduction through the wall-channel and also with and without heat exchange stream-cooling medium i.e. air. For this case, we have used the optimized parameters to study WGS for the three case of membrane micro-channel reactor. Here, we have considered palladium as membrane for this study which has an infinite selectivity towards H2 against any other species. The synthesis gases from a steam reformer or autothermal reactor are used as the feed gas, while we have considered there is no sweep gas. A published WGS reaction rate with the commercial 5 wt. % copper on alumina catalyst is incorporated into the model. From our study, we have seen that we need small micro-channel reactor length with heat conduction as compared to without heat conduction through wall-channel. III