Document Type : Research Paper


University of Technology, Department of Chemical Engineering ,Baghdad, Iraq,


Absorption of CO2 into promoted-NH3 solution utilize a packed column (1.25 m long, 0.05m inside diameter) was examined in the present work. The process performance of four different blended promoters monoethanolamine (MEA)+ piperazine (PZ), piperazine (PZ)+ potassium argininate (ArgK) and monoethanolamine +potassium argininate was compared with unpromoted-NH3 solution by evaluated the absorption rate (φ_(CO_2 )) and overall mass transfer coefficient (K_(G,CO_2.) a_v) over the operating ranges of the studied process variables (1-15Kpa initial partial pressure of CO2, 5-15 Liter/min gas flow rate, 0.25-0.85 Liter/min liquid flow rate). The results exhibit that the absorption behavior and efficiency can be enhanced by rising volumetric liquid flow rate and initial CO2 partial pressure. However, the gas flow rate should be kept at a suitable value on the controlling gas film. Furthermore, it has been observed that the (PZ+ArgK) promoter was the major species that can accelerate the absorption rate and reached almost 66.166% up to123.23% over that of the unpromoted-NH3 solution.


[1] C.T. Molina, C. Bouallou, "Assessment of different methods of CO2 capture in post combustion using ammonia as solvent", J. Clean. Prod. 103,463–468, 2015.
[2] H. Jooa , S. J. Chob , K. Na, "Control of CO2 absorption capacity and kinetics by MgO-based dry sorbents promoted with carbonate and nitrate salts", Journal of CO2 Utilization 19, 194–201,2017.
[3] B. Aghel , E. Heidaryan , S. Sahraie, M.Nazari , "Optimization of monoethanolamine for CO2 absorption in a microchannel Reactor" , Journal of CO₂ Utilization 28 ,264–273,2018.
[4] H.E. Benson, J.H. Field, R.M. Jimeson, "CO2 Absorption Employing Hot Potassium Carbonate Solutions", Chemical Engineering Progress, 50,356-364,2018.
[5] G. Hua, N. J. Nicholas, K. H. Smith, K. A. Mumford, S. E. Kentish, G. W. Stevens, "Carbon dioxide absorption into promoted potassium carbonate solutions: A review", International Journal of Greenhouse Gas Control, 53,28–40,2016
[6] F. Wang, J. Zhao, H. Miao, J. Zhao, H. Zhang, J. Yuan, J. Yan, "Current status and challenges of the ammonia escape inhibition technologies in ammonia-based CO2 capture process", Applied Energy ,230 734–749,2018.
[7] T. Suda, M. Iijma, "Countercurrent Absorption of CO2 in a Real Flue Gas into Aqueous Alkanolamine Solutions in a Wetted Wall Column", Environ. Progress, 16, 200-207,1997.
[8] R. J. Little, G.F. Versteeg, W.P.M. van Swaaij," Kinetics of CO2 with Primary and Secondary Amines in Aqueous Solutions—I. Zwitterion Deprotonation Kinetics for DEA and DIPA in Aqueous Blends of Alkanolamines", Chem. Eng. Sci., 47, 2027-2035,1992.
[9] N.Haimour, A.Bidarian, O.C. Sandall, "Kinetics of the Reaction between Carbon Dioxide and Methyldiethanolamine" Chem. Eng. Sci. 42, 1393-1398, 1987.
[10] R.J.Little, W.P M.van Swaaij, G.F. Versteeg, "The Kinetics of Carbon Dioxide with Tertiary Amines in Aqueous Solution", AIChE J., 36, 1633-1640,1990.
[11] Y. F. Diao, X. Y. Zheng, B. S. He, C.H. Chen, X. C. Xu, "Experimental study on capturing CO2 greenhouse gas by ammonia scrubbing", Energy Convers. Manage, 45 , 2283–2296,2004.
[12] Q. Zeng, Y. Guo, Z. Niu, W. Lin , "Mass Transfer Coefficients for CO2 Absorption into Aqueous Ammonia Solution Using a Packed Column", Ind. Eng. Chem. Res., 50, 10168–10175,2011.
[13] G. H.Kim, S. Y.Park, J. K.You, W. H.Hong, J.N.Kim, J. D.Kim, "CO2 absorption kinetics in a CO2-free and partially loaded aqueous ammonia solution", Chemical Engineering Journal, 250, 83-90,2014.
[14] F. Chu, L. Yang, X. Du, Y. Yang, "Mass transfer and energy consumption for CO2 absorption by ammonia solution in bubble column", Applied Energy, 190,1068–1080,2017.
[15] A.C.Yeh, H.L. Bai, Comparison of ammonia and monoethanolamine solvents to reduce CO2 greenhouse gas emissions, The Science of the Total Environment 228 (1999)121-133.
[16] D. Gonzalez-Garza, R. R. Tinoco, C. "Bouallou ,Comparison of Ammonia, MonoEthanolAmine, DiEthanolAmine and MethylDiEthanolAmine Solvents to Reduce CO2 Greenhouse Gas Emissions", 12th International Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, PRES'09, May 2009, Rome, Italy. The Italian Association of Chemical Engineering, 18,279-284, 2009
[17] M. Fang, Q. Xiang, X. Zhou, Q. Ma, Z. Luo, "Experimental study on CO2 absorption into aqueous ammonia-based blended absorbents", Energy Procedia ,61, 2284 – 2288,2014
[18] C. T.Molina , C. Bouallou ,"Comparison of post-combustion CO2 capture by solutions of ammonia and organic amines: Assessment using direct and indirect contactors ", Energy Procedia,63, 550 – 558,2014.
[19] F. Shakerian, K.Kim, J. E. Szulejko, J. W. Park ,"A comparative review between amines and ammonia as sorptive media for post-combustion CO2 capture", Applied Energy ,148 10–22,2015.
[20] J.L. Kang, D. S.H. Wong ,S.S. Jang , C.S. Tan , "A comparison between packed beds and rotating packed beds for CO2 capture using monoethanolamine and dilute aqueous ammonia solutions", International Journal of Greenhouse Gas Control, 46 ,228–239,2016.
[21] D.Bonalumi, G.Valenti,S. Lillia, P.L.Fosbøl, K.Thomsen, "A layout for the carbon capture with aqueous ammonia without salt precipitation", Energy Procedia ,86, 134–143,2016
[22] N. Yang , D.Y.Xu , H.Yu , W.Conway , M.Maeder , P.Feron , "Potassium sarcosinate promoted aqueous ammonia solution for post‐combustion capture of CO2", Greenhouse Gases: Science and Technology, 4, 555-257,2014.
[23] H. Yu , Q.Y. Xiang , M.X. Fang, P. Y. Q.Feron , Promoted CO2 absorption in aqueous ammonia . Greenhouse Gas Sci Technol 2, 1 – 9,2012.
[24] L. Li , W.H.H. Yu , H.Tang, "CO2 absorption by piperazine promoted aqueous ammonia solution: Absorption kinetics and ammonia loss" , Greenhouse Gas Sci Technol ,3, 231 – 245 ,2013.
[25] S. A Al-Naimi, F.T.Jasim, A. N. Kokaz," Dynamic Study of Carbon Dioxide Absorption Using Promoted Absorbent in Bubble Column Reactor", Engineering and Technology Journal, 37(partC),70-78, 2019.
[26] C. K.Ahn, K.Han, M. S.Lee, J. Y.Kim,H. D.Chun,Y,Kim,J. M.Park, " Experimental studies of additives for suppression of ammonia vaporization in the ammonia based CO2 capture process" , Energ Procedia, 37, 7108 – 7116,2013.
[27] JK. You , H. Park , SH. Yang , WH. Hong , W. Shin , JK. Kang , "Influence of additives including amine and hydroxyl groups on aqueous ammonia absorbent for CO2 capture" . J Phys Chem, B 112, 4323 – 4328,2008.