ORALS

SESSION: MoltenWedAM-R11	Kipouros International Symposium (8th Intl. Symp. on Sustainable Molten Salt, Ionic & Glass-forming Liquids & Powdered Materials)
Wed. 30 Nov. 2022 / Room: Game
Session Chairs: Amr Henni; Session Monitor: TBA

11:30: [MoltenWedAM01] OS Plenary
High Carbon Dioxide Capacity and Thermophysical Properties of Aqueous Piperazine Solutions Blended with 1-Butyl-3-Methylimidazolium Acetate
Firuz Philip¹ ; Amr Henni² ; ¹University of Regina, REGINA, Canada; ²University of Regina, Regina, Canada;
Paper Id: 38 [Abstract]

Anthropogenic CO2 emission is driving global warming, hence causing a drastic change in earth's geological and ecological systems. One of the solutions to reduce CO2 emission is to capture it from large point sources and store in geological strata or use it in enhanced oil recovery (EOR). Among many technologies, amine-based CO2 capture process is the most mature one and it offers high CO2 capture capacity and rapid kinetics. However, high regeneration energy, degradation and corrosion for the amine systems [1] compelled researchers to find alternate solvents. Ionic liquids (ILs) known as green solvents are molten salts at room temperature fulfil those criteria of low regeneration energy, negligible volatility and high thermal stability.[2] But, low CO2 uptake and high viscosity is the hindrance for deployment in CO2 capture operation [3]. To improve CO2 uptake, researcher have deployed strategies of functionalizing ILs with amines then known as task specific ionic liquids (TSILs)[4], but costly synthesis and purification steps, excessive viscosity forming gel like solids upon CO2 uptake are major obstruction for CO2 capture operation. An alternate strategy of blending the amines with ILs have shown promising results, such blended systems retain the desired properties of ILs but exclude the drawbacks of TSILs such as high synthesis cost and high viscosity. Moreover, the regeneration process requires lower energy as ILs replaces water fully or partially without compromising the absorption performance. A number of blended systems have been reported in the literature, however, in search of better blended systems with higher CO2 capacity but lower viscosity, new blended systems comprising of water, amines (Piperazine (PZ)) and ILs (1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) were investigated. <br />Herein, the concentration of PZ was kept constant at 15 wt.%, while the concentration of ionic liquid (ILs) was varied from 0 to 60 wt.% by replacing the corresponding amount of water. Experiments were conducted up-to a CO2 partial pressure of 300 kPa at (313 and 333) K. In addition, the density and viscosity of all the blended systems were measured for the temperature range of (303 to 333) K at atmospheric pressure. The results indicated that the CO2 uptake in all blended systems increased with the increase in CO2 partial pressure. In addition, CO2 uptake decreases for all systems with an increase in temperature. No significant change in CO2 uptake was observed for the addition of ILs up to 30 wt.% to aqueous PZ, however a dramatic increase in CO2 uptake was observed for ILs concentration of 60 wt.%. Moreover, it was found that the viscosities of the blended systems are significantly lower than the pristine [Bmim][Ac] as well as other functionalized ionic liquids (TSILs) reported in the literature. The results reveal that aqueous PZ + [Bmim][Ac] blended systems have the potential to overcome the drawbacks of IL/TSILs while retaining superior CO2 capture performance.

References:
[1] T.E. Akinola, E. Oko, M. Wang, Study of CO 2 removal in natural gas process using mixture of ionic liquid and MEA through process simulation, Fuel. 236 (2019) 135–146. https://doi.org/10.1016/j.fuel.2018.08.152.\n[2] Y. Zhao, X. Zhang, S. Zeng, Q. Zhou, H. Dong, X. Tian, S. Zhang, Density, viscosity, and performances of carbon dioxide capture in 16 absorbents of amine + ionic liquid + H2O, ionic liquid + H2O, and Amine + H2O systems, J. Chem. Eng. Data. 55 (2010) 3513–3519. https://doi.org/10.1021/je100078w.\n[3] X. Zhang, X. Zhang, H. Dong, Z. Zhao, S. Zhang, Y. Huang, Carbon capture with ionic liquids: Overview and progress, Energy Environ. Sci. 5 (2012) 6668–6681. https://doi.org/10.1039/c2ee21152a.\n[4] E.D. Bates, R.D. Mayton, I. Ntai, J.H. Davis, CO 2 Capture by a Task-Specific Ionic Liquid, J. Am. Chem. Soc. 124 (2002) 926–927. https://doi.org/10.1021/ja017593d.

SESSION: MoltenWedAM-R11	Kipouros International Symposium (8th Intl. Symp. on Sustainable Molten Salt, Ionic & Glass-forming Liquids & Powdered Materials)
Wed. 30 Nov. 2022 / Room: Game
Session Chairs: Amr Henni; Session Monitor: TBA

11:55: [MoltenWedAM02] OS
Selectivity of CO2 over ethane in four [Tf2N] and three [FSI] based ionic liquids of importance in the sweetening of natural gas
Devjyoti Nath¹ ; Ali Tajouri¹ ; Amr Henni² ; ¹University of Regina, REGINA, Canada; ²University of Regina, Regina, Canada;
Paper Id: 59 [Abstract]

<p>Anthropogenic emission of carbon dioxide (CO2) is accelerating global warming. One of the technologically advanced techniques for mitigating CO2 emission is to capture CO2 from the major point of sources such as flue-gas and store in geological storage. Apart from the storage in geological formation, captured CO2 can also be used in enhanced oil recovery. Furthermore, CO2 capture process is also used for natural gas sweetening to maintain the quality of natural gas. CO2 capture with the alkanolamine based chemical solvents is the most efficient technique that has been used for long-time, but this technique is still not economical due to high regeneration cost, high amount of solvent degradation and high corrosiveness. Ionic liquids (ILs) which are molten salt with a melting point below 373.15 K [1] have received enormous research emphasis recently as an alternative to reactive solvents as they require much less energy for regeneration and they possess special physical properties such as non-flammable, negligible vapor pressure, high stability, etc.<br />Previous study showed that the anion part of the ILs has more significant effect on the solubility of gases in ILs and the cation has a minor effect [2]. Moreover, the presence of S=O groups and fluorination in anion increase solubility of CO2 in ILs [3]. Due to the presence of S=O groups and fluorination in bis(trifluoromethylsulfonyl)imide ([Tf2N]) and bis(fluorosulfonyl)imide ([FSI]) anion, four [Tf2N] based ILs and three [FSI] based ILs were selected for this study. The major objectives of this study were to investigate the solubility of carbon dioxide (CO2) and ethane (C2H6) in [Tf2N] and [FSI] anion based ILs, estimate the selectivity towards CO2 over C2H6 for these ILs and compare the solubility of CO2 and selectivity among these ILs.<br />Solubility of CO2 and C2H6 in [Tf2N] and [FSI] ionic liquids, {N,N-dimethyl-N-ethyl-N-(3-methoxy-propyl)ammonium bis(trifluoromethylsulfonyl)imide, 1-Allyl-3H-imidazolium bis(trifluoromethyl sulfonyl)imide, 1-(3-Hydroxy propyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, N,N-diethyl-N-methyl-n-(2-methoxyethyl)ammonium bis(trifluoromethanesulfonyl)imide, 1-Methyl-1-propylpiperidinium bis(fluorosulfonyl)imide, N-propyl- n-methylpyrrolidinium bis(fluorosulfonyl)imide, and N,n-diethyl-n-methyl-n-propylammonium bis(fluorosulfonyl)imide} were measured at (303.15, 323.15, and 343.15) K and at pressures up to 1.5 MPa with a gravimetric microbalance. Solubility of CO2 and C2H6 in these ILs increased significantly with the increase in pressure in a linear manner and reduced with an increase in temperature. Henry's law constants, enthalpies and entropies for the absorption of CO2 and C2H6 were estimated from the solubility data. Experimental solubility data were correlated with the Peng-Robinson (PR) equation of state. The selectivities towards carbon dioxide (CO2) over C2H6 for these ILs were also estimated. Results showed that [Tf2N] based ILs exhibited higher CO2 solubility compared to [FSI] based ILs, while [FSI] based ILs exhibited higher selectivity towards CO2.</p>

References:
<p>REFERENCES:\n[1] Turnaoglu, T., Minnick, D. L., Morais, A. R. C., Baek, D. L., Fox, R. V., Scurto, A. M., &amp; Shiflett, M. B. (2019). Journal of Chemical &amp; Engineering Data, 64(11), 4668-4678.\n[2] Anthony, J. L., Anderson, J. L., Maginn, E. J., &amp; Brennecke, J. F. (2005). The Journal of Physical Chemistry B, 109(13), 6366-6374.\n[3] Muldoon, M. J., Aki, S. N., Anderson, J. L., Dixon, J. K., &amp; Brennecke, J. F. (2007). The Journal of Physical Chemistry B, 111(30), 9001-9009.</p>