Measurement and Correlation for Vapor Pressure and Excess Enthalpy of the New Working Pairs：Water/Ethanol/Methanol + Ionic Liquids 1-Ethyl-3-Methylimidazolium Diethylphosphate

Abstract:

Three binary solutions composed of ionic liquid (IL), 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM] [DEP]), and selected refrigerants (water, ethanol or methanol) were proposed as new working pairs for absorption heat pumps or absorption refrigerators. The vapor–liquid equilibrium (VLE) data were measured by a static method at different temperatures and at different ILs mole factions and correlated by the None-Random Two Liquids (NRTL) activity coefficient models, and the average relative deviation were less than 3.3%. The solutions showed strong negative deviation from the Raoult's Law and were able to absorb vapor of water, ethanol or methanol. The excess enthalpies were measured and correlated at 298.15 K and atmospheric pressure. The results indicated that the mixing of [EMIM] [DEP] with water, ethanol or methanol were exothermal. The proposed solutions were proved to possess one of the fundamental features that a working pair must have in absorption cycle.

• Periodical: Advanced Materials Research (Volumes 524-527)
• Pages: 1697-1701
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.524-527.1697
• Online since: May 2012
• Authors: Xiao Dong Zhang, Da Peng Hu, Zong Chang Zhao
• Keywords: Correlation, Excess Enthalpy, Ionic Liquid (IL), Vapor Pressure, Working Pairs

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