Reactor Performance Plane

This figure is a plot of the ratio of packed bed membrane reactor (MR) yield to plug flow reactor (PFR) yield, against the ratio of MR maximum temperature rise to PFR maximum temperature rise. The top left quadrant is the region in which the membrane reactor gives improved yield with no higher maximum temperature. Da is the ratio of reaction rate to feed rate, while B is related to the dimensionless heat of reaction. For fixed values of B and Da the membrane reactor model was solved for a series of increasing values of the permeability through the membrane of the distributed reactant. This resulted in a trajectory in the membrane performance plane shown to the right, that started at low yield and temperature rise ratios, and in general both increased as the amount of reactant increased. Three types of trajectory are illustrated: for B=14, Da=1 the MR temperature rise exceeded that of the PFR while the yield was still less, so no range of membrane permeability gave rise to an advantage; for B=14, Da=3 the MR to PFR yield ratio exceeded unity for a range of permeability, before falling below unity again; and for B=20, Da=6 the MR to PFR yield ratio again exceeded unity for a range of permeability, after which the MR to PFR temperature rise ratio exceeded unity.