Research output per year
Research output per year
H. Mert Polat, Frédérick de Meyer, Céline Houriez, Othonas A. Moultos, Thijs J.H. Vlugt^{*}
Research output: Contribution to journal › Article › Scientific › peer-review
We developed an open-source chemical reaction equilibrium solver in Python (CASpy, https://github.com/omoultosEthTuDelft/CASpy) to compute the concentration of species in any reactive liquid-phase absorption system. We derived an expression for a mole fraction-based equilibrium constant as a function of excess chemical potential, standard ideal gas chemical potential, temperature, and volume. As a case study, we computed the CO_{2} absorption isotherm and speciation in a 23 wt % N-methyldiethanolamine (MDEA)/water solution at 313.15 K, and compared the results with available data from the literature. The results show that the computed CO_{2} isotherms and speciations are in excellent agreement with experimental data, demonstrating the accuracy and the precision of our solver. The binary absorptions of CO_{2} and H_{2}S in 50 wt % MDEA/water solutions at 323.15 K were computed and compared with available data from the literature. The computed CO_{2} isotherms showed good agreement with other modeling studies from the literature while the computed H_{2}S isotherms did not agree well with experimental data. The experimental equilibrium constants used as an input were not adjusted for H_{2}S/CO_{2}/MDEA/water systems and need to be adjusted for this system. Using free energy calculations with two different force fields (GAFF and OPLS-AA) and quantum chemistry calculations, we computed the equilibrium constant (K) of the protonated MDEA dissociation reaction. Despite the good agreement of the OPLS-AA force field (ln[K] = −24.91) with the experiments (ln[K] = −23.04), the computed CO_{2} pressures were significantly underestimated. We systematically investigated the limitations of computing CO_{2} absorption isotherms using free energy and quantum chemistry calculations and showed that the computed values of μ_{i}^{ex} are very sensitive to the point charges used in the simulations, which limits the predictive power of this method.
Original language | English |
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Pages (from-to) | 2616-2629 |
Journal | Journal of chemical theory and computation |
Volume | 19 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2023 |
Research output: Thesis › Dissertation (TU Delft)
Polat, H. M. (Creator), De Meyer, F. (Creator), Houriez, C. (Creator), Moultos, O. (Creator) & Vlugt, T. J. H. (Creator), TU Delft - 4TU.ResearchData, 17 Aug 2023
DOI: 10.4121/F30869D9-1300-4DAE-AED8-DA8992DA6976
Dataset/Software: Dataset