Estimando parâmetros de interação binária para a equação de Peng-Robinson via otimização multiobjetivo: um estudo com a regra clássica de mistura de Van Der Waals

Abstract

Cubic equations of state, despite their mathematical simplicity, have proved to be very versatile in the simulation of thermodynamic models. They are able to represent the continuity between fluid phases and, consequently, can be used to represent vapor-liquid equilibrium (V LE) of pure substances and mixtures. Over time, these equations have gained wide acceptance in the oil industry as a robust and reliable model for predicting V LE of high pressure systems. Mixing rules are used in combination with cubic equations of state for a complete representation of mixtures and fluids. These mixing rules require empirically determined binary interaction parameters Kij to describe the V LE more accurately. The lack of these binary interaction parameters often results in inaccurate V LEs. In recent decades, there has been an increase in the use of multi-objective optimization to solve various optimization problems in different areas of mathematics and engineering. Based on this approach, the objective of this work is to estimate the binary interaction parameters Kij , using the classic van der Waals rule of mixtures, linked to the Peng-Robinson equation of state, applying the multi-objective optimization method MOPSO light. The present work shows excellent results in minimizing the errors of the analyzed properties (pressure and composition), of the Kij parameters for 22 non-polar mixtures in comparison with four other equations found in the literature.