Development of a novel approach for modeling acid gas solubility in alkanolamine aqueous solution

In this communication, a new approach for the modeling of acid gas (H2S/CO2) solubility in aqueous solutions of alkanolamines (MEA, DEA, TEA, MDEA and DGA) is introduced. The modeling and calculation approach is comparatively easier than similar methods presented in the literature and is capable of solving a non-linear set of equations using a Newton-Raphson algorithm. The distinct advantages of the approach are the ability to model solubility for the systems concerned via significantly reduced calculation routines and computational times, and without the use of optimization methods, while producing comparable modeling performance. A detailed development of the model construction and computational approach is presented, along with possible problems, as well as proposed solutions. The proposed method (Soltani Panah, Mohammadi, Ramjugernath: SMR) is demonstrated for the estimation of the solubility of H2S/CO2 in the aforementioned alkanolamines using the Deshmukh-Mather model. The results obtained from the SMR method were compared with that using the Smith-Missen method. The methods have been compared in terms of accuracy and convergence speed. Moreover, for examining capability of the SMR method to predict the solubility of H2S and CO2 once they are being absorbed together, the solubility of the latter two acid gases in aqueous solution of DEA was estimated and compared using the SMR and the Smith-Missen algorithms.