Membrane reactors for catalytic series and series-parallel reactions

The use of membrane reactors to improve the yield of intermediate products of series and series-parallel heterogeneous catalytic reactions has been investigated. For series reactions the most critical dimensionless parameters related to improving the yield are a Damköhler-Peclet number product (rate of reaction relative to rate of membrane permeation) and the permeability of the intermediate product relative to the reactant. The relative inert gas sweep rate, the pressure differential between the reactant and sweep zones, and the rate of the desired reaction relative to the undesired reaction also affect performance. When series-parallel reactions are considered the relative permeabilities of the reactants are also important in addition to the critical parameters identified for series reactions. For both classes of reactions, mathematical models have been used to identify ranges of these parameters where a membrane reactor can substantially increase the yield of intermediate products compared to a conventional packed bed reactor.