Generalized Mass Balance for Two Phase Systems

For the sake of generality, we now develop most general mass-balance equations for a two phase system in which each phase has multiple inputs and multiple outputs and in which each phase is undergoing reactions within its boundaries. 

A two-phase heterogeneous system with multiple inputs, multiple outputs, and multiple reactions in each phase and with mass transfer between the two phases 

To change the mass-balance equations (6.34) and (6.35) into design equations we replace rj by V rj and fj by V fj, where r and f denote the rates of reaction per unit volume of the reaction mixture, or per unit mass of catalyst for catalytic reactions for example. More details of the design equations are given below. 

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