Modeling of Selective Hydrogen Sulfide Absorption Using MDEA Solution in a Packed Column

Document Type : Research Article


Department of Chemical Engineering, Faculty of Engineering, Persian Gulf University, Bushehr, I.R. IRAN


In this paper, a steady-state model based on mass transfer for selective absorption of hydrogen sulfide gas in MethylDiEthanolAmine (MDEA) solution, in the packed absorption tower is presented. This model is able to predict the concentration and temperature profiles in gas and liquid phases for the (MDEA-H2S-CO2-H2O) system. In order to predict the profile of CO2 concentration, the second-order kinetic constants of reaction between gas and MDEA solution was used. Also, among the existing kinetic data, the best one was selected. In addition, the effective parameters in obtaining these profiles and the maximum point of selectivity factor were examined in this model. In order to evaluate accuracy of proposed model, the results were compared with from a pilot plant test as well as using  operating data from absorption packed tower of the gas sweetening unit of phases 4 and 5 of South Pars Gas Complex. The obtained results reveal an acceptable compatibility between experimental data and prediction of the presented model.


Main Subjects

[1] Pacheco M.A., Rochelle G.T., Rate-Based Modeling of Reactive Absorption of CO2 and H2S into Aqueous Methyldiethanolamine, Ind. Eng. Chem. Res., 37, p. 4107 (1998).
[2] Bolhar N., Friedl A., Koss U., Tork T., Modeling SelectiveH2S Absorption and Desorption in an Aqueous MDEA-Solution Using a Rate-Based Nonequilibrium Approach, Chem. Eng. Proc., 43, p. 701 (2004).
[3] Pandya J.D., Adiabatic Gas Absorption and Stripping with Chemical Reaction in Packed Towers, Chem. Eng. Commun., 19, p. 343 (1983). 
[4] Tontiwachwuthikul P., Meisen, A., Lim CJ., CO2 Absorption by NaOH- Monoethanolamine and 2-Amino-2-Methyl-1-Propanol Solutions in a Packed Column, Chem Eng Sci., 47, p. 381 (1992).
[5] Gabrielsen J., Michelsen M.L., Stenby E.H., Kontogeorgis G.M., Modeling of CO2 Absorber Using an AMP Solution, AIChE J., 52, p. 3443 (2006).
[6] Mandal B. P., Biswas A. K., Bandyopadhyay S.S., Selective Absorption of H2S from Gas Streams Containing H2S and CO2 in Aqueous Solutions of N-Methyldiethanolamine and 2-Amino-2-Methyl-1-Propanol., Sep. Purif. Technol., 35, p. 191 (2004).
[7] Posey M.L., Rochelle G.T., A Thermodynamic Model of Methyldiethanolamine-CO2-H2S-Water, Ind. Eng. Chem. Res., 36 (9), p. 3944 (1997). 
[8] Posey M., "Thermodynamic Model for Acid Gas Loaded Aqueous Alkanolamine Solutions", Ph.D. Dissertation, the University of Texas at Austin, Austin, TX, (1996).
[9] Al-Ghawas H.A., Hagewiesche D.P., Ruiz-Ibanez G., Sandall O.C., Physicochemical Properties Important for Carbon Dioxide Absorption in Aqueous Methyldiethanolamine, J. Chem. Eng. Data, 34(4), p. 385 (1989).
[10] Little R.J., Van Swaaij W.P.M., Versteeg G.F., Kinetics of CO2 with Tertiary Amines in Aqueous Solutions, AIChE J., 3 (11), p. 1633 (1990).
[11] Meng-Hui Li., Jiun-Jie KO., Kinetics of Absorption of Carbon Dioxide into Solutions of N-Methyldiethanolamine+Water, Chem. Eng. Sci., 55, p. 4139 (2000).
[12] Jamal A., Meisen A., Jim C., Kinetics of Carbon Dioxide Absorption and Desorption in Aqueous Alkanolamine Solutions Using a Novel Hemispherical Contactor-II. Experimental Results and Parameter Estimation, Chem. Eng. Sci., 61, p. 6590 (2006).
[13] Mandal B., Shyamalendu S., Bandyopadhyay S., Simultaneous Absorption of CO2 and H2S into Aqueous Blends of N-Methyldiethanolamine and Diethanolamine, Environ. Sci. Technol., 40 (19), p. 6076 (2006).
[14] Onda K., Takeuchi H., Okumoto Y., Mass Transfer Coefficients between Gas and Liquid Phases in Packed Columns, J.Chem. Eng. Jpn., 1, p. 56 (1968).
[15] Bird R.B., Stewart, W.E., Lightfoot E.N., “Transport Phenomena”, John Wiley & Sons, New York, (1960).
[16] Ayyaz M., Abdul Mutalib M., Wilfred C., Murugesan T., ShafeeqA.,  Viscosity, Refractive Index, Surface Tension, and Thermal Decomposition of Aqueous N-Methyldiethanolamine Solutions from 298.15 to 338.15 K., J. Chem. Eng. Data, 53, p. 2226 (2008).
[17] Rinker E.B., Hanna O.T., Sandall O.C., Asymptotic Models for H2S Absorption into Single and Blended Aqueous Amines, AIChE J., 43(1), p. 58 (1997).
[18] Snijder E.D., Te Riel, M.J.M., Versteeg G.F., van Swaaij W.P.M., Diffusion Coefficients of Several Aqueous AlkanolamineSolutions, J. Chem. Eng. Data, 38, p. 475 (1993).
[19] Reid R.C., Poling BE., “The Properties of Gases and Liquids”, 4th Ed., New York, McGraw-Hill, (1987). 
[20] Design Institute for Physical Properties, “DIPPR Evaluated Pure Component Database”, American Institute of Chemical Engineers, New York, (2005).
[21] Chiu L-F., Liu H-F., Li M-H., Heat Capacity of Alkanolamines by Differential Scanning Calorimetry., J. Chem. Eng. Data, 44, p. 631 (1999).
[22] "Engineering Data Book, Physical Properties", 12th ed., Sec. 23, Gas Processors Supply Association, Tulsa, Oklahoma, (2004).
[23] Barbara M., Hvard L., Sandall C., Physical Solubility of Hydrogen Sulfide in Aqueous Solutions of 2-(tert-Butylaminoo PDF) ethanol, J. Chem. Eng. Data, 45 (6), p. 1201 (2000).
[24] Afkhamipour M., Khorrami Z., Gholizadeh A., Rate-Based Modeling for CO2 Absorption into AMP Solution in a Random Packed Column., IPCBEE, 14, p. 135 (2011).
[25] "Operating Manual of Refinery Phases 4&5 of South Pars Gas Company".
[26] Kasiri N., Ghayyem M.A.,Rate Based Model in H2S and CO2 Absorption Column Using Alkanolamine Solutions., Int. J. Eng. Sci., 19, p. 89 (2008).