This paper presents the last results obtained using a new optimization procedure based on the vapor-liquid equilibrium in mixtures of two chemicals. This method was developed to solve complex optimization problems with variables in real domains. The search for the optimum is done by simulating the equilibrium of phases by means of a simple thermodynamic model widely applied in the chemical process industry. Each variable is treated as the most volatile component of a saturated binary system at a given temperature and pressure. The changes in each element of solution vector are made by using two new movement operators, the bubble point and the dew point. The algorithm has been tested with new mathematical reference functions producing results comparable to those achieved by other procedures.