Molecular dynamics simulation and experimental verification of a biphasic solvent for CO2 capture.

[Display omitted] • Effects of DETA and NMP on CO 2 absorption via MD simulation were investigated. • C-N absorption bond formation and DEEA catalytic role were revealed. • Optimal Composition: 3:2.5:1 DETA: DEEA: NMP ratio found for efficient CO 2 capture. • Biphasic Variability: NMP ratios impact the solid or liquid rich-phase formation. • CN and PRDF parameters analyzed at the atomic scale; C-N bond length is 1.7–1.77 Å. In the context of solvent-based carbon capture, researchers and industries are often interested in improvements in the efficiency of CO 2 capture along with the reduction in the required energy. This study employs molecular dynamics (MD) simulation based on a reax force field and experimental investigation to study the effects and main mechanisms of a mutual amine absorbent including diethylenetriamine (DETA) and diethylethanolamine (DEEA), accompanied by NMP and water co-solvents, on the performance of CO 2 capture in a phase change system. The implementation of time-dependent partial radial distribution functions (TD-PRDF, g α β r t m) and coordination number (CN) analyses revealed the significant formation of C-N bonds between carbon (C) derived from CO 2 and nitrogen (N) within the solution. The direct relationship between changes in DETA molar ratios and CO 2 loading, coupled with examining the catalytic role of DEEA in facilitating CO 2 removal through protonation, has been thoroughly studied with MD. The experimental methodology was followed to validate the MD results. The optimum composition, DETA: DEEA: NMP with a molar ratio of 3:2.5:1, as determined through MD simulations exhibits g α β r | t m = 9.848, CN=0.403 at t m = 1 ns. The stable C-N absorption bond length is calculated to be between 1.7 and 1.77 Å. Experimental results confirm a CO 2 loading capacity of 0.93 mol/mol for this composition. [ABSTRACT FROM AUTHOR]