ABSTRACT
The sizing of a chemical reactor starts with a consideration of the material balance equation for the reactor. This applies equally to batch and continuous flow systems. This chapter develops material balance equations for the principal classes of reactor on the assumption that flow conditions in the reactor are 'ideal'. Reactors in which the flow conditions approximate to plug flow are normally tubular and may or may not contain a bed of catalyst. The residence time (t) of any element of fluid in a reactor is the time spent by that element in the reactor. In an ideal plug flow reactor the residence times of all elements of fluid for given flow rate are the same, i.e. there is a single residence time. In an 'ideal' continuous stirred tank reactor (CSTR), the fluid elements leaving the reactor will have spent a range of times within the reactor.
