Measurement of the absorption rate of carbon dioxide into aqueous diethanolamine
- Brigham Young Univ., Provo, UT (United States). Dept. of Chemical Engineering
Aqueous alkanolamine solutions are commonly used in natural gas sweetening processes to remove the acid gases CO{sub 2} and H{sub 2}S. Absorption rates of gaseous CO{sub 2} into aqueous diethanolamine (DEA) solutions were measured in a quiescent, inverted-tube diffusiometer by monitoring the rate of pressure drop. The absorption rate was found to be insensitive to the diffusion coefficient of CO{sub 2} in solution but very sensitive to the diffusion rate of bicarbonate, protonated DEA, and carbamate ions. Evidence also suggested that chemical reaction equilibrium is rapid relative to diffusion. The diffusion coefficient of DEA in water was also measured using a Taylor dispersion apparatus. A numerical model was developed and used to regress diffusion coefficients of bicarbonate, carbamate, and protonated amine from measured absorption rates. CO{sub 2} absorption rates and diffusion coefficients of bicarbonate, carbamate, and protonated DEA were obtained at 298.2 K and 318.2 K in solutions containing 20, 35, and 50 mass % DEA in water.
- OSTI ID:
- 624361
- Journal Information:
- Journal of Chemical and Engineering Data, Journal Name: Journal of Chemical and Engineering Data Journal Issue: 3 Vol. 43; ISSN JCEAAX; ISSN 0021-9568
- Country of Publication:
- United States
- Language:
- English
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