ROBUST PHASE STABILITY ANALYSIS USING INTERVAL METHODS
Mark A. Stadtherr, Carol Ann Schnepper · 1998
Conventional equation solving and optimization techniques for solving the phase stability problem may fail to converge or may converge to an incorrect result. A technique for solving the problem with mathematical certainty is needed. One approach to providing such assurance can be found in the use of interval methods. An interval Newton/generalized bisection technique is applied here to solve the phase stability problem. Results for two models of liquid-phase systems, using several different feed compositions, indicate that the technique used is reliable and very efficient. Keywords Phase stability, Interval computations, Nonlinear equation solving, Interval Newton method, Tangent plane criterion, NRTL equation Introduction The determination of phase stability is a recurrent problem in the computation of phase equilibria, and thus is especially important in the analysis and design of separation operations such as distillation and extraction. The problem is basically to determine whet...