New approach in the design of reactions and separations using an ionic liquid and carbon dioxide as solvents: Phase equilibria in two selected ternary systems

Due to mainly environmental and safety reasons, green chemistry is receiving a great deal of attention in the last couple of years. The development of more benign, environmentally friendly processes with less hazardous solvents is currently the major focus of a wide variety of research activities. However, the development of efficient processes requires knowledge on the phase equilibria of the system, which are unfortunately poorly studied. Therefore, in this study we present the phase equilibria for ternary mixtures of an ionic liquid, carbon dioxide (CO2) and two organic solutes, namely 1-phenylethanol and acetophenone, at CO2 concentrations varying from 10 up to 50 mol%. The two organic solutes studied are the reactant and product of the hydrogenation of acetophenone into 1-phenylethanol. Data were measured for pressures up to 14 MPa and over a temperature range from 278 to 370 K.

Graphical abstractThe phase equilibria for ternary mixtures bmim[BF4] + organic + CO2 at CO2 concentrations varying from 10 up to 50 mol% has been investigated, with acetophenone and 1-phenylethanol as organic solutes. The results are compared with other ternary and binary systems, and the possibility of performing the hydrogenation of acetophenone in ionic liquid-CO2 combined solvents is demonstrated.Figure optionsDownload full-size imageDownload as PowerPoint slide