Industrial & Engineering Chemistry Research, Vol.53, No.49, 19322-19330, 2014
Distillable Protic Ionic Liquid 2-(Hydroxy)ethylammonium Acetate (2-HEAA): Density, Vapor Pressure, Vapor-Liquid Equilibrium, and Solid-Liquid Equilibrium
Recently it has been found that certain ionic liquids (ILs) have notable vapor pressures (Earle et al. Nature 2006, 439, 831-834). These ILs may be important in various novel technologies, but they may also be important in postcombustion carbon captures as side products. In this work a distillable protic ionic liquid (PIL) 2-(hydroxy)ethylammonium acetate (2-HEAA) was prepared from monoethanolamine (MEA) and acetic acid (HAc) and it was purified with a Vigreaux type distillation column under vacuum. Density was measured for the MEA + 2-HEAA and HAc + 2-HEAA systems with a DMA HP densimeter from 293 to 363 K. The Redlich-Kister polynomial was used to model the density data. Vapor-liquid equilibrium was measured for the H2O + HAc + 2-HEAA system with a static total pressure apparatus at 347 K. Solid-liquid equilibrium was measured for the H2O + HAc + 2-HEAA system with a visual method. The NRTL activity coefficient model was used to model the vapor-liquid and solid-liquid equilibrium data.