The comparative modeling of solubility of carbon dioxide in amine solutions using SAFT-HR and PC-SAFT equation of state

In this paper, we applied PC-SAFT and SAFT-HR equations of state so as to reproduce the solubility of carbon dioxide in aqueous diethanolamine solution. By using these equations, we have been able to model the solubility of carbon dioxide in aqueous amine solution in more than 350 experimental data points with wide range of amine molar concentration (0.01-0.12), temperature (300 K - 478 K), carbon dioxide partial pressure (0.0001 KPa - 5473 KPa), and carbon dioxide loading (0.04 - 1.1). Ternary systems including water, carbon dioxide and diethanolamine have also been modeled by PC-SAFT and SAFT-HR equations of state based on bubble pressure algorithm. Binary interaction parameters are set to zero to show the genuine capability of equations of state in reproducing such experimental data. Provided modeling results have been obtained from MATLAB R2019b software for PC-SAFT equation of state are less deviated with experimental data. Overall average relative deviation of SAFT-HR and PC-SAFT are 45.452% and 4.374% respectively which show that PC-SAFT is a robust equation of state in predicting the solubility data of carbon dioxide in aqueous alkanolamine solutions.

Automated summary

In this study, the solubility of carbon dioxide in aqueous diethanolamine solution was modeled using PC-SAFT and SAFT-HR equations of state. These equations were able to accurately reproduce the solubility data from over 350 experimental points, covering a wide range of variables including amine molar concentration, temperature, carbon dioxide partial pressure, and carbon dioxide loading. PC-SAFT and SAFT-HR equations were also used to model ternary systems consisting of water, carbon dioxide, and diethanolamine using the bubble pressure algorithm. The results showed that PC-SAFT was more reliable with an overall average relative deviation of 4.374% compared to 45.452% for SAFT-HR, indicating its robustness in predicting the solubility of carbon dioxide in aqueous alkanolamine solutions.