Millisecond catalytic wall reactors: I. Radiant burner

Short-contact-time reactors have potential for high throughput in reactors much smaller than their traditional counterparts. While they operate adiaba tically, heat can be exchanged at short contact time by integrating heat ex change into the reactor. Hot effluent of exothermic reaction systems can be redirected over feed gases to recuperate a portion of the sensible heat. P lacing catalyst directly on reactor walls eliminates the resistance to heat transfer in the thermal boundary layer so that heat released by combustion can be effectively coupled to an emitter, such as in a radiant burner. A r adiant heater was constructed operated, and simulated incorporating short c ontact time, energy recuperation, and a catalytic wall. This burner operate d stably for many hours at a filing rate from similar to 50 to > 160 kW/m(2 ) at a radiant temperature of 950 to 1,150 K at a radiant efficiency of sim ilar to 60% with a residence time in the reacting zone of similar to 10 ms. This reactor was modeled using 2-D Navier-Stokes equations including detai led models for chemistry and heat transport. Temperature and compositions p redicted agreed well with experimental measurements.