Exploiting the Gibbs‐Duhem equation in separation calculations
S. Venkataraman, Ángelo Lucia · AIChE Journal · 1986
Abstract Various ways of building quasi‐Newton matrix approximations that satisfy the special form of the Gibbs‐Duhem equation are studied. Partition symmetry, the separability of the functions in γ and in ϕ, and the method of iterated projections are used in order to develop thermodynamically consistent matrix approximations with good secant information. Many examples are presented which show that exploiting the special form of the Gibbs‐Duhem equation results in improved numerical performance. Ways of exploiting the Gibbs‐Helmholtz equation in addition to the special form of Gibbs‐Duhem equation, and thus the isobaric form of the Gibbs‐Duhem equation, are also discussed.