AbstractThe optimal control problem is formulated, and a weak maximum principle for such distributed parameter systems is derived. From this principle an efficient computational algorithm is presented which allows the simultaneous solution of the problems of both catalyst distribution (along the reactor) and optimal control. Detailed numerical examples are worked for isothermal reactors, adiabatic reactors, and adiabatic reactors with both a catalyst distribution problem and an optimal control problem. For irreversible reactions constant conversion policies are found to be optimal a significant portion of the time.