6. Computer science applied to material and enthalpy balances

Software specifically designed to solve chemical engineering problems has a relatively long history (see History box). In fact, automatic calculation using digital computers is well suited to solving problems involving the dimensioning of material and heat transfer operations: compartmentalized operations comprise numerous stages whose operation is governed by formally identical material and heat balances. Assuming that these stages are ideal, equilibrium relationships link the compositions of the effluent phases in each stage. The properties of inter-stage balances allow these balances to be expressed in a recursive form, which is ideally suited to computer-aided design.

Thus, since the 1970s, major commercial software packages have been successfully applied to the dimensioning and operating analysis of equipment used by the process industries. They are commonly...