New model predicts solubility in glycols

A new numerical model predicts the amount of H2S and CO2 absorbed per volume of different glycols circulated vs. the partial pressure of acid-gas components and the absorber’s temperature. The model covers the full range of dehydration-plant operating conditions and a wide range of experimental data results. This study shows that the proposed approach is more accurate than routine equations of state approaches in predicting the solubility of acid gases in different glycols. Equation-of-state methods do a generally good job of determining vapor-phase properties, but the liquid phase is much more difficult, especially when the liquid contains dissimilar molecules and polar molecules, such as H2S, CO2, alcohols, and glycols, that are not handled easily. This article also compares results of the proposed model with experimental data and Peng-Robinson equation-of-state results. The average absolute deviation for the proposed numerical model falls between 2 and 3%, or 2.5% on average. The equation of state’s average absolute deviation results fall between 4 and 24%, or 14% on average.