Simulating the reactions of CO2 in aqueous monoethanolamine solution by reaction ensemble Monte Carlo using the continuous fractional component method

Sayee Prasaad Balaji; Satesh Gangarapu; Mahinder Ramdin; Ariana Torres-Knoop; Han Zuilhof; Earl L V Goetheer; David Dubbeldam; Thijs J H Vlugt

doi:10.1021/acs.jctc.5b00160

Simulating the reactions of CO2 in aqueous monoethanolamine solution by reaction ensemble Monte Carlo using the continuous fractional component method

J Chem Theory Comput. 2015 Jun 9;11(6):2661-9. doi: 10.1021/acs.jctc.5b00160.

Authors

Sayee Prasaad Balaji¹, Satesh Gangarapu², Mahinder Ramdin¹, Ariana Torres-Knoop³, Han Zuilhof^{2

4}, Earl L V Goetheer⁵, David Dubbeldam³, Thijs J H Vlugt¹

Affiliations

¹ Engineering Thermodynamics, Process & Energy Department, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology , Leeghwaterstraat 39, 2628CB Delft, The Netherlands.
² Laboratory of Organic Chemistry, Wageningen University , Dreijenplein 8, 6703HB Wageningen, The Netherlands.
³ Van't Hoff Institute for Molecular Sciences, University of Amsterdam , Science Park 904, 1098XH Amsterdam, The Netherlands.
⁴ Department of Chemical and Materials Engineering, King Abdulaziz University , Jeddah, Saudi Arabia.
⁵ TNO , Leeghwaterstraat 46, 2628CA Delft, The Netherlands.

PMID: 26575563
DOI: 10.1021/acs.jctc.5b00160

Abstract

Molecular simulations were used to compute the equilibrium concentrations of the different species in CO2/monoethanolamine solutions for different CO2 loadings. Simulations were performed in the Reaction Ensemble using the continuous fractional component Monte Carlo method at temperatures of 293, 333, and 353 K. The resulting computed equilibrium concentrations are in excellent agreement with experimental data. The effect of different reaction pathways was investigated. For a complete understanding of the equilibrium speciation, it is essential to take all elementary reactions into account because considering only the overall reaction of CO2 with MEA is insufficient. The effects of electrostatics and intermolecular van der Waals interactions were also studied, clearly showing that solvation of reactants and products is essential for the reaction. The Reaction Ensemble Monte Carlo using the continuous fractional component method opens the possibility of investigating the effects of the solvent on CO2 chemisorption by eliminating the need to study different reaction pathways and concentrate only on the thermodynamics of the system.