For reactions in which the rate depends only on the concentration of one species [i.e., –rA = f(CA)], it may be convenient to report –rA as a function of concentration rather than conversion. We can rewrite the design equation for a plug-flow reactor
in terms of the concentration, CA, rather than in terms of conversion for the special case when v = v0. On the CDROM we develop and discuss the following equation for space time and the figure below.