AbstractThe mathematical problems of reactor design and performance depend primarily on the solution of a set of partial differential or difference equations. These equations are linear if the reactions are first‐order, if temperature variations are not significant, and if mass transfer by diffusion obeys Fick's law. When a reactor problem can be solved for a single irreversible first‐order reaction, it can also be solved for a system of coupled first‐order reactions of any number of chemical species and of arbitrary compl