- Title
- The determination of the Henry's coefficient of reactive gases - an example of CO₂ in aqueous solutions of monoethanolamine (MEA)
- Creator
- Li, Lichun; Burns, Robert C.; Maeder, Marcel; Puxty, Graeme; Wang, Shujuan; Yu, Hai
- Relation
- Chemical Engineering Science Vol. 173, p. 474-482
- Publisher Link
- http://dx.doi.org/10.1016/j.ces.2017.08.008
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2017
- Description
- The Henry's Coefficient of CO₂ is a fundamental property, it quantifies the equilibrium between the partial pressure of CO₂ in the gas phase and the concentration of dissolved free CO₂ in the liquid phase. This value is critical for simulation and may lead to improvements in the process of post combustion capture of CO₂. However, because of its reactive nature, CO₂ reacts in amine solutions and forms multiple carbon-containing species, so that the free CO₂ concentration is very small and difficult to determine. The "N₂O analogy" has been used to estimate the physical solubility of CO₂ based on the assumption that the two gases behave similarly in water and amine solutions. In the current study, a direct way is proposed for the determination of the Henry's Coefficient of CO₂ in MEA solutions. The method only requires vapor-liquid equilibriu m (VLE) measurements of the MEA-CO₂-H₂O system; and all equilibrium/protonation constants for all solution reactions are sourced from the open literature while activity coefficients for all ionic species were estimated using the Davis equation. The free CO₂ concentration in solution can be computed using the total MEA concentration, total CO₂ concentration and temperature, which allows the determination of the Henry's Coefficient from the CO₂ partial pressure. A 10-parameter polynomial is used to approximate the Henry's Coefficient as a function of the total MEA concentration, total CO₂ concentration and temperature. VLE calculations were performed using the liquid-phase equilibrium calculations and the polynomial function calculating the Henry's Coefficient, and the results show the VLE calculations are adequate to describe the VLE data.
- Subject
- Henry’s coefficient; PCC; MEA; CO₂; reactive gases
- Identifier
- http://hdl.handle.net/1959.13/1395699
- Identifier
- uon:33929
- Identifier
- ISSN:0009-2509
- Language
- eng
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