Temperature Control by Reactant Feed

1 Temperature Control by Reactant Feed - The underlying idea of this innovation is that if the reactant is distributed along the tube in a PBMR configuration, then for exothermic reactions, such as partial oxidations, the release of energy will be more gradual. This could lead to a lower hotspot, and to a wider feasible range of operation. 

For an inlet temperature of 640 K, the fixed bed exhibited runaway. With the membrane reactor, profiles from inlet temperatures of 630 and 640 K showed no hotspots, and the inlet temperature eould be increased to 670 K without runaway. The yield to desired products was lower, however, due to the reduced reaction rates in the 02-metered membrane reactor. So for the same inlet conditions and catalyst volume, the increased temperature control of the membrane reactor did not improve seleetivity enough to overcome the decreased conversion typically seen in the reactant feed configuration. 

More recent work ° has examined whether running the membrane reactor at a higher inlet temperature than the fixed bed is advantageous, at the same catalyst volume. Preliminary results show that a small increase in the inlet temperature of 

These studies have shown that distributing the O2 feed via a membrane in hydrocarbon oxidations results in both improved selectivities and better temperature control. The challenge will be to adjust reactor operating conditions to maintain these advantages while overcoming the lower catalyst point utilization that accompanies them. 

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