동일한 음이온을 가진 두 가지 종류의 이온성 액체인 1-ethy-3-methylimidazolium trifluoromethanesulfonate ([emim] [TfO])와 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][TfO])를 대상으로 약 303 K로부터 약 343 K의 온도 범위와 약 30 MPa까지의 압력 범위에서 이온성 액체에 녹는 황화수소(H2S)와 메탄(CH4)의 용해도를 측정하였다. 가변부피투시창이 장착된 고압용 상평형 장치를 사용하여 온도를 변화시키면서 여러 가지 조성을 갖는 기체 + 이온성 액체 혼합물의 기포점 압력을 측정함으로써 이온성 액체에서의 기체의 용해도를 결정하였다. 이온성 액체에 대한 H2S의 용해도는 압력이 증가함에 따라 증가하였으며 온도가 증가함에 따라 감소하였다. 반면에 이온성 액체에 대한 CH4의 용해도는 압력이 증가함에 따라 크게 증가하였으나 온도의 영향은 거의 없었다. 동일한 음이온을 갖는 이온성 액체인 [emim][TfO]와 [bmpyr][TfO]에 대하여 H2S의 용해도는 몰랄 농도 기준으로 온도 및 압력 조건에 관계없이 거의 유사하였다. 이온성 액체[emim][TfO]에 대한 H2S와 CH4의 용해도를 비교한 결과, H2S의 용해도가 CH4의 용해도보다 훨씬 컸다. 동일한 종류의 이온성 액체에 대하여 본 연구를 통해 얻은 H2S와 CH4의 용해도 데이터를 문헌으로부터 얻은 CO2의 용해도 데이터와 비교하였다. 같은 압력 및 온도 조건에서 비교할 때, CO2의 용해도는 H2S와 CH4의 용해도의 사이에 있었다.

Solubility data of hydrogen sulfide (H2S) and methane (CH4) in two kinds of ionic liquids with the same anion: 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][TfO]) and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate ([bmpyr][TfO]) are presented at pressures up to about 30 MPa and at temperatures between 303 K and 343 K. The gas solubilities in ionic liquids were determined by measuring the bubble point pressures of the gas + ionic liquid mixtures with various compositions at different temperatures using a high-pressure equilibrium apparatus equipped with a variable-volume view cell. The H2S solubilities in ionic liquid increased with the increase of pressure and decreased with the increase of temperature. On the other hand, the CH4 solubilities in ionic liquid increased significantly with the increase of pressure, but there was little effect of temperature on the CH4 solubility. For the ionic liquds [emim][TfO] and [bmpyr][TfO] with the same anion, the solubility of H2S as a molality basis was substantially similar, regardless of the temperature and pressure conditions as a molar concentration basis. Comparing the solubilities of H2S and CH4 in the ionic liquid [emim][TfO], the solubilities of H2S were much greater than those of CH4. For the same type of ionic liquid, the solubility data of H2S and CH4 obtained in this study were compared to the solubility data of CO2 from the literature. When compared at the same pressure and temperature conditions, the CO2 solubility was in between the solubility of H2S and CH4.

Ionic Liquid Hydrogen Sulfide Methane Solubility Natural Gas Sweetening

Karadas F, Atilhan M, Aparicio S, Energy Fuels, 24, 5817 (2010)
Mortazavi-Manesh S, Satyro MA, Marriott RA, AIChE J., 59(8), 2993 (2013)
Ramdin M, Balaji SP, Torres-Knoop A, Dubbeldam D, de Loos TW, Vlugt TJH, J. Chem. Eng. Data, 60(10), 3039 (2015)
Lee JH, Shim SB, Korean Chem. Eng. Res., 52(3), 314 (2014)
D’Alessandro DM, Smit B, Long JR, Angew. Chem.-Int. Edit., 49, 6058 (2010)
Khakharia P, Huizinga A, Lopez CJ, Sanchez CS, Mercader FD, Vlugt TJH, Goetheer E, Ind. Eng. Chem. Res., 53(33), 13195 (2014)
MacDowell N, Florin N, Buchard A, Hallett J, Galindo A, Jackson G, Adjiman CS, Williams C, Shah N, Fennell P, Energy Environ Sci., 3, 1645 (2010)
Lei ZG, Dai CN, Chen BH, Chem. Rev., 114(2), 1289 (2014)
Ramdin M, de Loos TW, Vlugt TJH, Ind. Eng. Chem. Res., 51, 8149 (8177)
Kim JE, Kang JW, Lim JS, Korean J. Chem. Eng., 32(8), 1678 (2015)
Lee BC, Nam SG, Korean J. Chem. Eng., 32(3), 521 (2015)
Nam SG, Lee BC, Korean J. Chem. Eng., 30(2), 474 (2013)
Jin YR, Jung YH, Park SJ, Baek IH, Korean Chem. Eng. Res., 50(1), 35 (2012)
Cho MH, Lee H, Kim H, Korean Chem. Eng. Res., 48(1), 1 (2010)
Camper D, Bara J, Koval C, Noble R, Ind. Eng. Chem. Res., 45(18), 6279 (2006)
Scovazzo P, J. Membr. Sci., 343(1-2), 199 (2009)
Sumon KZ, Henni A, Fluid Phase Equilib., 310(1-2), 39 (2011)
Mortazavi-Manesh S, Satyro MA, Marriott RA, AIChE J., 59(8), 2993 (2013)
Carvalho PJ, Coutinho JAP, Energy Environ. Sci., 4, 4614 (2011)
Ramdin M, Amplianitis A, Bazhenov S, Volkov A, Volkov V, Vlugt TJH, de Loos TW, Ind. Eng. Chem. Res., 53(40), 15427 (2014)
Ramdin M, Amplianitis A, de Loos TW, Vlugt TJH, Fluid Phase Equilib., 375, 134 (2014)
Heintz YJ, Sehabiaue L, Morsi BI, Jones KL, Luebke JD, Pennline HW, Energy Fuels, 23(15), 4822 (2009)
Shokouhi M, Adibi M, Jalili AH, Hosseini-Jenab M, Mehdizadeh A, J. Chem. Eng. Data, 55(4), 1663 (2010)
Jalili AH, Mehdizadeh A, Shokouhi M, Ahmadi AN, Hosseini-Jenab M, Fateminassab F, J. Chem. Thermodyn., 42(10), 1298 (2010)
Jalili AH, Safavi M, Ghotbi C, Mehdizadeh A, Hosseini-Jenab M, Taghikhani V, J. Phys. Chem. B, 116(9), 2758 (2012)
Shiflett MB, Niehaus AMS, Yokozeki A, J. Chem. Eng. Data, 55(11), 4785 (2010)
Shiflett MB, Yokozeki A, Fluid Phase Equilib., 294(1-2), 105 (2010)
Sakhaeinia H, Jalili AH, Taghikhani V, Safekordia AA, J. Chem. Eng. Data, 55(12), 5839 (2010)
Jalili AH, Rahmati-Rostami M, Ghotbi C, Hosseini-Jenab M, Ahmadi AN, J. Chem. Eng. Data, 54(6), 1844 (2009)
Rahmati-Rostami M, Ghotbi C, Hosseini-Jenab M, Ahmadi AN, Jalili AH, J. Chem. Thermodyn., 41(9), 1052 (2009)
Sakhaeinia H, Taghikhani V, Jalili AH, Mehdizadeh A, Safekordi AA, Fluid Phase Equilib., 298(2), 303 (2010)
Kumelan J, Kamps APS, Tuma D, Maurer G, J. Chem. Eng. Data, 52(6), 2319 (2007)
Kumelan J, Kamps APS, Tuma D, Maurer G, Ind. Eng. Chem. Res., 46(24), 8236 (2007)
Raeissi S, Peters CJ, Fluid Phase Equilib., 294(1-2), 67 (2010)
Shin EK, Lee BC, Lim JS, J. Supercrit. Fluids, 45(3), 282 (2008)
Jung YH, Jung JY, Jin YR, Lee BC, Baek IH, Kim SH, J. Chem. Eng. Data, 57(12), 3321 (2012)
Shin EK, Lee BC, J. Chem. Eng. Data, 53(12), 2728 (2008)
Guide to the Expression of Uncertainty in Measurement, International Organization of Standardization (ISO), Geneva, Switzerland(1995).