Partition coefficients of furan derivative compounds in 1-n-butyl-3-methylimidazolium chloride ([bmim][Cl])–supercritical CO2 biphasic systems and their correlation and prediction with the LSER-δ model

Infinite dilution partition coefficients of furan and furan derivative compounds (2-methylfuran, 2-ethylfuran, furfural and furfuryl alcohol) between ionic liquid ([bmim][Cl]: 1-n-butyl-3-methylimidazolium chloride) and supercritical carbon dioxide (scCO2) were measured at temperatures from 313 to 353 K and at pressures from 9 to 21 MPa with a chromatographic method. A linear solvation energy relationship-solubility parameter (LSER-δ) model was applied to available data and was compared with a proposed entropic term and with the Sanchez–Lacombe equation of state (SL EoS). The average relative deviations (ARDs) of furan derivative compounds, which were newly measured, for SL EoS model, LSER-δ model and modified LSER-δ model were within 3.2%, 14.9% and 14.7%, respectively. The LSER-δ   model can be applied as prediction model for Kw3∞ of ionic liquid–CO2 systems for which solute descriptors are available.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► New partition coefficient data of furan derivative compounds are reported. ► Ionic liquid [bmim][Cl]–supercritical CO2 biphasic system properties. ► Correlation of data with Sanchez–Lacombe equation of state. ► LSER-solubility parameter (δ) model for compressible phases.