Interval analysis for thermodynamic calculations in process design: a novel and completely reliable approach

Recently, a robust new computational technique, based on interval analysis, has been developed for solving the difficult nonlinear problems arising in the modeling of phase behavior. This technique can be used, with mathemati cal and computational guarantees of certainty, to find the global optimum o f a nonlinear function or to enclose any and all roots of a system of nonli near equations. As shown in the applications here to phase stability analys is and to the location of homogeneous azeotropes, it provides a method that can guarantee that the correct result is found; thus, eliminating computat ional problems that may potentially be encountered with currently available techniques. The method is initialization independent; it is also model ind ependent, straightforward to use, and can be applied in connection with any equation of state or activity coefficient model. (C) 1999 Elsevier Science B.V. All rights reserved.