Application of Surface Tension Model for Prediction of Interfacial Speciation of CO₂-Loaded Aqueous Solutions of Monoethanolamine

Journal Article · Tue Apr 25 00:00:00 EDT 2017 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/acs.iecr.7b00041· OSTI ID:1461275

Matin, Naser S. ^[1]; Steckel, Janice A. ^[2]; Thompson, Jesse ^[1]; Sarma, Moushumi ^[1]; Liu, Kunlei  ^[3]

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1. Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research
2. National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)
3. Univ. of Kentucky, Lexington, KY (United States). Center for Applied Energy Research and Dept. of Mechanical Engineering

A thermodynamic platform in combination with experimental surface tension data is used to predict the surface phase speciation of CO₂-loaded aqueous solutions of 30 weight percent (%) monoethanolamine (MEA) at 20, 40, and 60 °C from their corresponding bulk phase speciation. The osmotic coefficient dependency of the surface tension of an electrolyte solution has been employed to estimate the surface tension. In order to calculate the osmotic coefficients, the Pitzer equation for the excess Gibbs energy was applied. According to the results of this study, molecular MEA, and to some extent protonated MEA and the MEA-carbamate have surface propensity and will accumulate at the surface phase. The carbonate ion shows nearly even distribution between bulk and surface phases, and bicarbonate displays a tendency to remain in the bulk phase that increases with CO₂ loading. The differences in the behaviors of protonated MEA, MEA-carbamate, carbonate and bicarbonate are due to differences among their sizes and polarizabilities. Using first principles calculations, the static isotropic dipole polarizabilities for bicarbonate, carbonate, MEA carbamate and protonated MEA were calculated. The bulk and surface phases’ ionic strengths reasonably represent this behavior of ionic species at the surface phase.

• Research Organization: National Energy Technology Laboratory (NETL), Pittsburgh, PA, Morgantown, WV (United States)
• Sponsoring Organization: USDOE; Duke Energy, Charlotte, NC (United States); Electric Power Research Inst. (EPRI), Palo Alto, CA (United States); Kentucky Dept. of Energy Development and Independence (KY-DEDI), Frankfort, KY (United States); Louisville Gas & Electric (LG&E), Louisville, KY (United States); Kentucky Utilities (KU), Lexington, KY (United States)
• OSTI ID: 1461275
• Report Number(s): NETL-PUB-20941
• Journal Information: Industrial and Engineering Chemistry Research, Vol. 56, Issue 19; ISSN 0888-5885
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

20 FOSSIL-FUELED POWER PLANTS
03 NATURAL GAS
surface tension
osmotic coefficient
monoethanolamine
speciation
polarizability