Estudo do equilíbrio líquido-vapor de misturas binárias a partir de equações de estado cúbicas

Abstract

Separation processes, important for various industries, involve specific mass transfer processes, such as distillation, and are based on the liquid-vapor equilibrium of substances present in various systems of economic interest. Given this, the quantitative description of multi-component systems involving liquid and vapor phases is relevant and the subject of studies. The experimental determination of these data is not always feasible considering time and cost constraints. Therefore, this work explores the use of equations of state as an analytical and predictive tool for obtaining liquid-vapor equilibrium data from a symmetric approach. The work used experimental data available in the literature as a reference for obtaining accuracy and precision data, applying the Soave-Redlich-Kwong, Peng-Robinson, and Peng-Robinson-Stryjek-Vera equations of state for binary systems relevant to the petroleum industry. Comparison with experimental results indicated that the use of this predictive method for systems involving carbon dioxide is limited, considering its particular behavior near the critical point. Nevertheless, promising results were obtained for the methane-ethane system, which is chemically similar, and for the C5H12+ C6H14 system, which exhibit high critical temperature values. Additionally, the impact of applying three analytical methodologies for determining the binary interaction component was analyzed, and in this context, the methodology proposed by (GAO et al., 1992) yielded the best results. Simulations were performed using the Python computational tool, which was considered suitable for simple analytical predictions, provided that the limitations proposed by the applied equations of state are considered.