文摘
The solubility of 5-hydroxymethylfurfural (HMF) in supercritical carbon dioxide (scCO2) with and without ethanol (mole fraction of ethanol x3 = 0, 0.025, and 0.050) as a cosolvent was measured by the cloud point at temperatures from (314.1 to 343.2) K and pressures from (8.54 to 19.71) MPa. It is demonstrated that the solubility of HMF increases with the increase of pressure at a fixed temperature but decreases with the increase of temperature at a fixed pressure. When ethanol is added into scCO2 as a cosolvent, the solubility of HMF increases greatly with the increase of the mole fraction of ethanol. The experimental data can be correlated by the Chrastil model and a modified Chrastil model with four adjustable parameters. The correlation results indicate that the association of HMF and CO2 is an endothermic process, and ethanol can reduce the energy of the process.