RESIDENCE TIME DISTRIBUTION AND MIXINGRESIDENCE TIME DISTRIBUTION AND MIXINGThe time spent by reactants and intermediates at reaction conditions determines conversion (and perhaps selectivity). It is therefore often important to understand the residence time distribution (RTD) of reaction species in the reactor. This RTD could be considerably different from what is expected from ideal reactor behavior. Reasons for the deviation could be channeling of fluid, recycling of fluid, or creation of stagnant regions in the reactor, as illustrated in Fig. 19-6.