The objective of this study is to measure solubility of CO2 in aqueous 2-amino-2-hydroxymethyl-1,3-propanediol (TRIS) solution. The physical properties such as the density of TRIS aqueous solution at elevated pressures were also measured. Additionally, this study investigates the feasibility of CO2 sequestration process using mineral precipitants.
The solubility of CO2 in 5 mass% and 10 mass% TRIS aqueous solution was measured using a Phase Equilibrium Analyzer (PEA) apparatus based on synthetic method at 318.15 K and 333.15 K and up to 10 MPa. The solubility of CO2 in TRIS aqueous solution decreases with increasing temperature and the solubility of CO2 in TRIS aqueous solutions increases with increasing TRIS concentration of the solutions. The modified Kent-Eisenberg model was used to correlate the equilibrium solubility of carbon dioxide in TRIS aqueous solution to determine deprotonation constant for TRIS aqueous solution. This model satisfactorily correlated experimental data with an acceptable average absolute deviation (AAD) 0.0009 %.
The density of 5 mass% and 10 mass% aqueous TRIS solutions were measured over the temperatures range from 288.15 K to 308.15 K and pressures range from 0.1 MPa to 25 MPa using DMA 512P Anton Paar densimeter. The density of TRIS aqueous solution is slightly higher than the density of water. The density of TRIS aqueous solution decreases with increasing the temperature and it increases with increasing TRIS concentration, and it increases as increasing pressure.
Three different mineral precipitants (CaCl2.2H2O and TRIS aqueous solution mixture, CaCl2.2H2O aqueous solution, and artificial sea water) can be feasibly employed in CO2 sequestration process at (308.15 and 328.15) K by producing solid carbonate. The amount of solid carbonate produced decreases as an increase of temperature for both mixtures. The mixture of CaCl2.2H2O- TRIS aqueous solution precipitant gives the highest amount of solid carbonate with 0.26 g and 0.65 g for both CO2 mixtures with 5 mass% and 10 mass% of TRIS solutions, respectively, at 308.15 K and produces 0.16 g and 0.36 g at 328.15 K for both CO2 mixtures with 5 mass% and 10 mass% of TRIS solutions, respectively. Low amount of solid carbonate (0.0008 g) was produced by using artificial sea water due to its low containing of calcium ions.

The objective of this study is to measure solubility of CO2 in aqueous 2-amino-2-hydroxymethyl-1,3-propanediol (TRIS) solution. The physical properties such as the density of TRIS aqueous solution at elevated pressures were also measured. Additionally, this study investigates the feasibility of CO2 sequestration process using mineral precipitants.
The solubility of CO2 in 5 mass% and 10 mass% TRIS aqueous solution was measured using a Phase Equilibrium Analyzer (PEA) apparatus based on synthetic method at 318.15 K and 333.15 K and up to 10 MPa. The solubility of CO2 in TRIS aqueous solution decreases with increasing temperature and the solubility of CO2 in TRIS aqueous solutions increases with increasing TRIS concentration of the solutions. The modified Kent-Eisenberg model was used to correlate the equilibrium solubility of carbon dioxide in TRIS aqueous solution to determine deprotonation constant for TRIS aqueous solution. This model satisfactorily correlated experimental data with an acceptable average absolute deviation (AAD) 0.0009 %.
The density of 5 mass% and 10 mass% aqueous TRIS solutions were measured over the temperatures range from 288.15 K to 308.15 K and pressures range from 0.1 MPa to 25 MPa using DMA 512P Anton Paar densimeter. The density of TRIS aqueous solution is slightly higher than the density of water. The density of TRIS aqueous solution decreases with increasing the temperature and it increases with increasing TRIS concentration, and it increases as increasing pressure.
Three different mineral precipitants (CaCl2.2H2O and TRIS aqueous solution mixture, CaCl2.2H2O aqueous solution, and artificial sea water) can be feasibly employed in CO2 sequestration process at (308.15 and 328.15) K by producing solid carbonate. The amount of solid carbonate produced decreases as an increase of temperature for both mixtures. The mixture of CaCl2.2H2O- TRIS aqueous solution precipitant gives the highest amount of solid carbonate with 0.26 g and 0.65 g for both CO2 mixtures with 5 mass% and 10 mass% of TRIS solutions, respectively, at 308.15 K and produces 0.16 g and 0.36 g at 328.15 K for both CO2 mixtures with 5 mass% and 10 mass% of TRIS solutions, respectively. Low amount of solid carbonate (0.0008 g) was produced by using artificial sea water due to its low containing of calcium ions.

[1] J.D. Figueroa, T. Fout, S. Plasynski, H. McIlvried, R.D. Srivastava, Advances in CO2 capture technology—The U.S. Department of Energy's Carbon Sequestration Program, Int. J. Greenhouse Gas Control, 2 (2008) 9-20.
[2] EIA, International Energy Outlook (2010).
[3] A. Belzil, C. Parent, Methodes de qualification des immobilisations chimiques d'une enzyme sur un support solide, Biochem. Cell. Biol., 83 (2005) 70-77.
[4] M. Wilson, XIII—Theory Facades, Proceedings of the Aristotelian Society (Hardback), 104 (2004) 273-288.
[5] N. Mahinpey, K. Asghari, P. Mirjafari, Biological sequestration of carbon dioxide in geological formations, Chem. Eng. Res. Des., 89 (2011) 1873-1878.
[6] G. Thomas, Subsurface sequestration of carbon dioxide — An overview from an Alberta (Canada) perspective, Int. J. Coal Geol., 43 (2000) 287-305.
[7] R. Yadav, N. Labhsetwar, S. Kotwal, S. Rayalu, Single enzyme nanoparticle for biomimetic CO2 sequestration, J. Nanopart. Res., 13 (2011) 263-271.
[8] K.S. Lackner, C.H. Wendt, D.P. Butt, E.L. Joyce Jr, D.H. Sharp, Carbon dioxide disposal in carbonate minerals, Energy, 20 (1995) 1153-1170.
[9] C. Hendriks, Carbon dioxide removal from coal-fired power plants (energy & environment), Kluwer Academic:  Dordrecht, The Netherlands, 1994.
[10] P. Mirjafari, K. Asghari, N. Mahinpey, Investigating the application of enzyme carbonic anhydrase for CO2 sequestration purposes, Ind. Eng. Chem. Res., 46 (2007) 921-926.
[11] N. Liu, G.M. Bond, A. Abel, B.J. McPherson, J. Stringer, Biomimetic sequestration of CO2 in carbonate form: Role of produced waters and other brines, Fuel. Process. Technol., 86 (2005) 1615-1625.
[12] L. Wang, I. Sondi, E. Matijević, Preparation of uniform needle-like aragonite particles by homogeneous precipitation, J. Colloid Interf. Sci., 218 (1999) 545-553.
[13] W. Wu, T. He, J.-F. Chen, X. Zhang, Y. Chen, Study on in situ preparation of nano calcium carbonate/PMMA composite particles, Mater. Lett., 60 (2006) 2410-2415.
[14] E. Blomen, C. Hendriks, F. Neele, Capture technologies: Improvements and promising developments, Energy Procedia, 1 (2009) 1505-1512.
[15] R.J. Hook, An investigation of some sterically hindered amines as potential carbon dioxide scrubbing compounds, Ind. Eng. Chem. Res., 36 (1997) 1779-1790.
[16] P.M.M. Blauwhoff, G.F. Versteeg, W.P.M. Van Swaaij, A study on the reaction between CO2 and alkanolamines in aqueous solutions, Chem. Eng. Sci., 39 (1984) 207-225.
[17] S. Ma'mun, V.Y. Dindore, H.F. Svendsen, Kinetics of the reaction of carbon dioxide with aqueous solutions of 2-((2-aminoethyl)amino)ethanol, Ind. Eng. Chem. Res., 46 (2006) 385-394.
[18] B.A. Oyenekan, Modeling of strippers for CO2 capture by aqueous amines, Ph.D Dissertation in: Chemical Engineering, University of Texas at Austin 2007.
[19] B.E. Roberts, A.E. Mather, Solubility of CO2 and H2S in a mixed solvent, Chem. Eng. Commun., 72 (1988) 201-211.
[20] S.K. Dash, A.N. Samanta, S.S. Bandyopadhyay, (Vapour liquid) equilibria (VLE) of CO2 in aqueous solutions of 2-amino-2-methyl-1-propanol: New data and modelling using eNRTL-equation, J. Chem. Thermodyn., 43 (2011) 1278-1285.
[21] Y. Liu, L. Zhang, S. Watanasiri, Representing vapor−liquid equilibrium for an aqueous MEA−CO2 system using the electrolyte nonrandom-two-liquid model, Ind. Eng. Chem. Res., 38 (1999) 2080-2090.
[22] A.B. Rao, E.S. Rubin, D.W. Keith, M. Granger Morgan, Evaluation of potential cost reductions from improved amine-based CO2 capture systems, Energ. Policy, 34 (2006) 3765-3772.
[23] J. Gabrielsen, CO2 capture from coal fired power plants, Ph.D Dissertation in: Chemical Engineering, Technical University of Denmark, 2007.
[24] D. Bailey, W., P. Feron, H.M., Capture post-combustion, Oil & Gas Science and Technology - Rev. IFP, 60 (2005) 461-474.
[25] G. Sartori, D.W. Savage, Sterically hindered amines for carbon dioxide removal from gases, Ind. Eng. Chem. Fundam., 22 (1983) 239-249.
[26] C.-W. Wang, A.N. Soriano, Z.-Y. Yang, M.-H. Li, Solubility of carbon dioxide in the solvent system (2-amino-2-methyl-1-propanol + sulfolane + water), Fluid Phase Equilib., 291 (2010) 195-200.
[27] P. Tontiwachwuthikul, A. Meisen, C.J. Lim, Solubility of carbon dioxide in 2-amino-2-methyl-1-propanol solutions, J. Chem. Eng. Data, 36 (1991) 130-133.
[28] A.K. Chakraborty, G. Astarita, K.B. Bischoff, CO2 absorption in aqueous solutions of hindered amines, Chem. Eng. Sci., 41 (1986) 997-1003.
[29] A.K. Saha, S.S. Bandyopadhyay, A.K. Biswas, Kinetics of absorption of CO2 into aqueous solutions of 2-amino-2-methyl-1-propanol, Chem. Eng. Sci., 50 (1995) 3587-3598.
[30] M. Kundu, S.S. Bandyopadhyay, Solubility of CO2 in water + diethanolamine + 2-amino-2-methyl-1-propanol, J. Chem. Eng. Data, 51 (2006) 398-405.
[31] M. Taha, M.-J. Lee, Buffer interactions: Densities and solubilities of some selected biological buffers in water and in aqueous 1,4-dioxane solutions, Biochem. Eng. J., 46 (2009) 334-344.

[32] M. Taha, M.-J. Lee, Buffer interactions: Solubilities and transfer free energies of TRIS, TAPS, TAPSO, and TABS from water to aqueous ethanol solutions, Fluid Phase Equilib., 289 (2010) 122-128.
[33] J.-Y. Park, S.J. Yoon, H. Lee, J.-H. Yoon, J.-G. Shim, J.K. Lee, B.-Y. Min, H.-M. Eum, Density, viscosity, and solubility of CO2 in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol, J. Chem. Eng. Data, 47 (2002) 970-973.
[34] J.-Y. Park, S.J. Yoon, H. Lee, Effect of steric hindrance on carbon dioxide absorption into new amine solutions:  Thermodynamic and spectroscopic verification through solubility and NMR analysis, Environ. Sci. Technol., 37 (2003) 1670-1675.
[35] D. Le Tourneux, I. Iliuta, M.C. Iliuta, S. Fradette, F. Larachi, Solubility of carbon dioxide in aqueous solutions of 2-amino-2-hydroxymethyl-1,3-propanediol, Fluid Phase Equilib., 268 (2008) 121-129.
[36] J.-Y. Park, S.J. Yoon, H. Lee, J.-H. Yoon, J.-G. Shim, J.K. Lee, B.-Y. Min, H.-M. Eum, M.C. Kang, Solubility of carbon dioxide in aqueous solutions of 2-amino-2-ethyl-1,3-propanediol, Fluid Phase Equilib., 202 (2002) 359-366.
[37] R.L. Kent, B. Eisenberg, Better data for amine treating, Hydrocarbon Process., 55 (1976) 87-90.
[38] R.D. Deshmukh, A.E. Mather, A mathematical model for equilibrium solubility of hydrogen sulfide and carbon dioxide in aqueous alkanolamine solutions, Chem. Eng. Sci., 36 (1981) 355-362.
[39] P. Debye, E. Huckel, On the theory of electrolytes. I. Freezing point depression and related phenomena, Zeit. Fr Phys., 24 (1923) 185-206.

[40] E.A. Guggenheim, R.H. Stokes, Activity coefficients of 2 : 1 and 1 : 2 electrolytes in aqueous solution from isopiestic data, Trans. Faraday Soc, 54 (1958) 1646-1649.
[41] G. Scatchard, Concentrated solutions of strong electrolytes, Chem. Rev., 19 (1936) 309-327.
[42] M.R. G.N. Lewis, K.S. Pitzer and L. Brewer, Thermodynamics, 2nd ed., McGraw Hill, New York, 1961.
[43] K.S. Pitzer, Thermodynamics of electrolytes. I. Theoretical basis and general equations, J. Phys. Chem., 77 (1973) 268-277.
[44] C.-C. Chen, H.I. Britt, J.F. Boston, L.B. Evans, Local composition model for excess Gibbs energy of electrolyte systems. Part I: Single solvent, single completely dissociated electrolyte systems, AIChE J., 28 (1982) 588-596.
[45] H. Renon, J.M. Prausnitz, Local compositions in thermodynamic excess functions for liquid mixtures, AIChE J., 14 (1968) 135-144.
[46] S.K. Dash, A.N. Samanta, S.S. Bandyopadhyay, Solubility of carbon dioxide in aqueous solution of 2-amino-2-methyl-1-propanol and piperazine, Fluid Phase Equilib., 307 (2011) 166-174.
[47] Y. Zhang, H. Que, C.-C. Chen, Thermodynamic modeling for CO2 absorption in aqueous MEA solution with electrolyte NRTL model, Fluid Phase Equilib., 311 (2011) 67-75.
[48] L. Zong, C.-C. Chen, Thermodynamic modeling of CO2 and H2S solubilities in aqueous DIPA solution, aqueous sulfolane–DIPA solution, and aqueous sulfolane–MDEA solution with electrolyte NRTL model, Fluid Phase Equilib., 306 (2011) 190-203.
[49] C.-C. Chen, L.B. Evans, A local composition model for the excess Gibbs energy of aqueous electrolyte systems, AIChE J., 32 (1986) 444-454.
[50] B. Sander, A. Fredenslund, P. Rasmussen, Calculation of vapour-liquid equilibria in mixed solvent/salt systems using an extended UNIQUAC equation, Chem. Eng. Sci., 41 (1986) 1171-1183.
[51] D.S. Abrams, J.M. Prausnitz, Statistical thermodynamics of liquid mixtures: A new expression for the excess Gibbs energy of partly or completely miscible systems, AIChE J., 21 (1975) 116-128.
[52] H. Nicolaisen, P. Rasmussen, J.M. Sorensen, Correlation and prediction of mineral solubilities in the reciprocal salt system (Na+, K+)(Cl−, SO42−)−H2O at 0–100°C, Chem. Eng. Sci., 48 (1993) 3149-3158.
[53] K. Thomsen, P. Rasmussen, Modeling of vapor–liquid–solid equilibrium in gas–aqueous electrolyte systems, Chem. Eng. Sci., 54 (1999) 1787-1802.
[54] M.-J. Lee, Y.-C. Tuan, H.-M. Lin, Pressure, volume, and temperature for mixtures of poly(ethylene glycol methyl ether)-350 + anisole and poly(ethylene glycol)-200 + anisole from 298 K to 338 K and pressures up to 50 MPa, J. Chem. Eng. Data, 45 (2000) 1100-1104.
[55] J.A. Nelder, R. Mead, A simplex method for function minimization, Comput. J., 7 (1965) 308-313.
[56] L.H. Jones, E. McLaren, Infrared absorption spectra of SO2 and CO2 in aqueous solution, J. Chem. Phys., 28 (1958) 995-995.
[57] M.E. Riepe, J.H. Wang, Infrared studies on the mechanism of action of carbonic anhydrase, J. Biol. Chem., 243 (1968) 2779-2787.
[58] S. Sowa, L.E. Towill, Infrared spectroscopy of plant cell cultures : Noninvasive measurement of viability, Plant Physiol., 95 (1991) 610-615.
[59] A. Sharma, A. Bhattacharya, Enhanced biomimetic sequestration of CO2 into CaCO3 using purified carbonic anhydrase from indigenous bacterial strains, J. Mol. Catal. B: Enzym., 67 (2010) 122-128.