Evaluation of Differential Evolution and Tabu Search for Benchmark and Phase Stability Problems

Phase stability (PS) problems play a crucial role in the simulation, design and optimization of separation process such as distillation and extraction. The problem involves the global minimization of tangent plane distance function (TPDF) known as tangent plane criterion. In this work, two promising global optimization techniques: differential evolution (DE) and tabu search (TS) have been evaluated for the first time and compared for benchmark and PS problems. A local optimization technique is used at the end of both TS and DE to improve the accuracy of the final solution. Benchmark problems involve 2 to 20 variables with a few to hundreds of local minima whereas PS problems consist of multiple components and modeled with popular thermodynamic models. The results show that DE is more reliable but computationally less efficient compared to TS for benchmark and PS problems tested.