| Recently, the synthesis of y-valerolactone (GVL) from hydrogenation of levulinic acid (LA) has become one of the key steps for the conversion of biomass to chemicals; it has been investigated by several groups. Supercritical carbon dioxide as a green solvent has been used in this reaction. It was demonstrated that organic solvent can be replaced supercritical carbon dioxide in this reaction. Study on the solubility of levulinic acid in supercritical carbon dioxide has very important significance on understanding the role of supercritical carbon dioxide in the hydrogenation conversion of levulinic acid. On the other hand, to perform the reaction mechanism of this three-phase catalytic hydrogenation reaction effectively, the solubility of hydrogen in the different composition liquid of reactant and product needs to be studied.Firstly, the solubility of levulinic acid in supercritical carbon dioxide in the absence and presence of ethanol (mole fraction of ethanol x3= 0.0,0.027, and 0.051) as a cosolvent was measured with a synthetic method at temperatures from (313.0 to 342.4K) and pressures from (8.0 to 19.0 MPa). It was demonstrated that the solubility of levulinic acid increases with increasing of pressure at a fixed temperature; the solubility decreases with the increasing of temperature at a fixed pressure. When ethanol was added into supercritical carbon dioxide as a co-solvent, the solubility of levulinic acid increases greatly, and it increases with the concentration of the added ethanol. The experimental solubility data can be correlated with the Chrastil model and a modified Chrastil model with four adjustable parameters with AARDs from (11.68 to 15.82)%.In this paper, the solubility of hydrogen in the liquid of levulinic acid+ water+γ-valerolactone was measured using a high-pressure variable volume view cell on analytical method at pressures from 0.75 to 5.25 MPa and temperatures from 353.15 to 453.15 K. The result shows that the solubility of hydrogen increases with the improving of pressure and temperature. The solubility of hydrogen in liquids increases with the order of levulinic acid(x1=0.37)+ water(x2=0.63)< levulinic acid< levulinic acid(x1=0.33)+ water (x2=0.33)+γ-valerolactone(x3=0.34)<γ-valerolactone, it means that the solubility in the liquid of this three-phase catalytic hydrogenation reaction increases with chemical reaction. An extension of Henry's law was employed to correlate the hydrogen solubility data, and the Henry's law coefficients were calculated. The Henry's law coefficients decreased with the increasing of temperature. The molar enthalpy of solution was positive and the molar entropy was negative.
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