Page 277 - Modeling of Chemical Kinetics and Reactor Design

Industrial and Laboratory Reactors 247

Figure 4-19. Stirred batch reactor. (Source: V. W. Weekman, “Laboratory
Reactors and Their Limitations,” AIChEJ, Vol. 20, p. 833, 1974. Used with
permission of the AIChEJ.)

rotate at high speeds to minimize external mass transfer effects, and
also maintain well-mixed fluid contents. This type of operation provides
good isothermal conditions, which can be maintained, and there is
good contact between the catalyst and the fluid. However, if the
catalyst particle size is small, there may be difficulties in containing
the particles in the paddle screens. This reactor rates well in ease of
sampling and analysis of the product composition. The residence time
of the solid is accurately known and, with good mixing, the gas-vapor
residence times can also be measured quite accurately. The dis-
advantage of this type of reactor is its unsteady state, which can affect
its selectivity. However, it is unable to generate useful data when the
catalyst being studied decays.