Modeling of Gas Solubility Process in Liquid Based on State Equations for Low Temperature Working Fluids

摘要

Data on solubility are necessary in modeling a number of processes of low-temperature equipment, as well as chemical production. At present, the amount of experimental information for promising industrial solutions is significantly limited. At the moment, the laws of Raoul and Henry diluted solutions, as well as thermodynamic models based on them, are mainly used for analytical determination of solubility. More promising is the thermodynamic approach considered in this work, which uses the general conditions of vapor-liquid equilibrium of the binary mixture. The necessity and relevance of this approach is noted in the literature on thermodynamics of diluted solutions. The aim of the research is to develop an algorithm for calculating of gas solubility in liquid using the equation of state and Newton's method to solve a system of nonlinear equations formed from the conditions of vapor-liquid equilibrium of binary mixtures. This algorithm has been tested for a number of binary cryo- and refrigerant systems. Using Newton's method to solve the solubility problem in question resulted in convergence of the calculation process in all computations. The results of solubility calculations and experimental data for nitrogen-neon, butane-ethylene systems are compared. As shown in this work, the use of empirical evidence on pure components only provides acceptable solubility accuracy for the binary systems mentioned above.