Prediction of H ₂S and CO ₂ solubilities in aqueous triethanolamine solutions using a simple model of Kent-Eisenberg type

Absorption of acid gases (H ₂S and CO ₂) by aqueous solutions of alkanolamines is the most commonly used process in the gas treatment industry. Recent process investigations on the use of triethanolamine (TEA) show its potential to render the gas sweetening operation more energy efficient in particular when mixed to methyldiethanolamine (MDEA). This paper presents a simple model of Kent-Eisenberg type that computes the dissociation of the protonated triethanolamine (TEA) equilibrium constant. The model can be used to correlate mixed acid gases solubility data over 2, 3.5, and 5 M of aqueous TEA solutions at 50, 75, and 100 °C. Results for the new model shows high fitting percentage errors for both acid gases; however, the model was able to predict H ₂S and CO ₂ partial pressures accurately for another set of unfitted data. Despite the highly fitted percentage errors, the model was used as an initial guess for a different Kent-Eisenberg model which resulted into a significantly lower percentage error at 50 °C.