Solubilities of gases in ionic liquids using a corresponding-states approach to Kirkwood-Buff solution theory

Measurements of the liquid-liquid phase diagrams of solutions of the ionic liquids (ILs) 1-dodecyl-3-methylimidazolium chloride (C12mimCl) in arenes (benzene, toluene, o-xylene, tetraline) and 1-tetradecyl-3-methylimidazolium chloride (C14mimCl) in CCl4 are reported and compared with those of solutions of trihexyl-tetradecyl-phosphonium halides (P666 14Cl, P666 14Br) in hydrocarbons and 1-alkyl-3-methylimidazolium tetrafluoroborates (CnmimBF4) in alcohols and water. The phase diagrams of solutions of tetrapentyl-ammonium bromide (N5555Br) in water and KI in SO2 are also discussed. Except for the KI/SO2 system, which features a lower critical solution point (LCSP), all systems have an upper critical solution point (UCSP) and show corresponding-states behavior. The experimental data are compared with results from simulations and theory concerning the model fluid of charged hard spheres in a dielectric continuum, termed restricted primitive model (RPM). The analysis in terms of of RPM variables shows agreement with the location of the critical point (CP) of the model with noticeable systematic deviations. However, for protic solvents, the CP becomes an LCSP, while in aprotic solvents the CP is a UCSP as expected for Coulomb systems. This indicates that in aprotic solvents, the phase transition is essentially determined by the Coulomb interactions, while in the solutions in protic solvents with hydrogen bonds, both Coulomb and solvophobic interactions are important.

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Regular Solution Theory for Low Pressure Carbon Dioxide Solubility in Room Temperature Ionic Liquids: Ionic Liquid Solubility Parameter from Activation Energy of Viscosity

Industrial & Engineering Chemistry Research ◽

10.1021/ie901837k ◽

2010 ◽

Vol 49 (12) ◽

pp. 5846-5853 ◽

Cited By ~ 60

Author(s):

Surya S. Moganty ◽

Ruth E. Baltus

Keyword(s):

Carbon Dioxide ◽

Activation Energy ◽

Ionic Liquid ◽

Ionic Liquids ◽

Regular Solution ◽

Solubility Parameter ◽

Room Temperature ◽

Room Temperature Ionic Liquids ◽

Regular Solution Theory ◽

Solution Theory

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Application of ionic liquids for separation of propyne from propylene: solubility and selectivity studies

Jurnal Teknik Kimia Indonesia ◽

10.5614/jtki.2010.9.3.5 ◽

2018 ◽

Vol 9 (3) ◽

pp. 106

Author(s):

Jelliarko Palgunadi ◽

Antonius Indarto ◽

Haryo Winoto ◽

Hoon Sik Kim

Keyword(s):

Hydrogen Bonding ◽

Ionic Liquids ◽

Regular Solution ◽

Solubility Parameter ◽

Room Temperature ◽

Material Selection ◽

Regular Solution Theory ◽

Solution Theory ◽

Bonding Interaction ◽

Cracking Process

Separation or removal of propyne from propylene, generated by naptha cracking process, is one of the most important processes in petrochemical industries because ppm level of propyne contained in feed olefins can serve as catalyst poisons in the polymerization of olefins. Recently, room temperature ionic liquids (RTILs) were introduced as novel solvents for the separation of various gases and hydrocarbons. RTIL is a salt composed of unsymmetrical organic cation and organic/inorganic anion which melts at room temperature. Prior to the decision of material selection for the effective separation of propyne/propylene employing RTIL, solubility behaviors and selectivities of propyne and propylene in various RTILs were investigated. For the solubility of propyne and propylene in 1-R-3-methylimidazolium-based RTILs, solubility measurement, thermodynamic analysis, and computational calculation strongly imply that the solubility of propyne is controlled by a trade-off between a specific solute-solvent interaction (hydrogen bonding of propyne-anion) and non bonding interaction (solubility parameter). In contrast, the solubility of propylene seems to be much strongly dependent on non-bonding interaction (solubility parameter) closely related to the physical attractive forces as suggested by regular solution theory. Thus, to achieve high selectivity of propyne over propylene, a RTIL with smaller-size and stronger hydrogen bonding ability should be employed.Keywords: propyne, propylene, solubility, selectivity, ionic liquidsAbstrakPemisahan senyawa propuna dari propena, yang dihasilkan oleh proses fraksionasi nafta adalah salah satu proses yang paling penting dalam industri petrokimia. Kontaminan propuna yang terkandung dalam umpan olefin dapat menjadi racun katalis dalam proses polimerisasi olefin. Kini cairan ionik temperatur ruang (RTIL) diperkenalkan sebagai pelarut baru untuk pemisahan berbagai gas dan hidrokarbon. RTIL adalah garam yang terdiri dari kation organik dan anion organik/anorganik asimetrik yang meleleh pada suhu kamar. Pemilihan senyawa pelarut RTIL yang tepat untuk pemisahan propuna / propena akan dibahas dalam tulisan ini. Dalam proses pelarutan propuna dalam RTIL berbasis 1-R-3-metilimidazolium, pengukuran kelarutan, analisis termodinamika, dan pemodelan mengisyaratkan bahwa kelarutan propuna dikendalikan oleh kompromi antara interaksi spesifik solut-pelarut (ikatan hidrogen propuna-anion) dan interaksi tak mengikat (parameter kelarutan). Sebaliknya, kelarutan propena sangat bergantung pada interaksi tak mengikat (parameter kelarutan) yang erat hubungannya dengan ikatan fisik seperti dipaparkan dalam teori larutan biasa (regular solution theory). Dengan demikian, untuk mencapai selektivitas tinggi terhadap propuna dibandingkan dengan propena, disarankan untuk menggunakan senyawa RTIL dengan ukuran molekul lebih kecil yang memiliki ikatan hidrogen lebih kuat.Kata Kunci: propuna, propena, kelarutan, absorpsi, cairan ionik

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