Abstract To intensify chemical processes, it is sometimes required to connect several reactors in series. In addition, real reactors are always modeled as combinations of ideal reactors. However, a detailed description of reactor combinations is not always covered in undergraduate lecturing. In this paper, the general equations to calculate the conversion in ideal reactors in both series and parallel are first derived. Next, the effect of the combination mode in which an irreversible first-order liquid phase reaction is carried out on the reactant conversion or the reactor volume is discussed. Finally, a general expression for the residence time distribution of the combination where one continuous stirred tank reactor and another plug flow reactor in series is obtained. Lecturing the combination of ideal reactors can help the students to enhance their critical and creative thinking skills.
