Research On The Modification Of Acetone As Solvent For Absorbing Carbon Dioxide Or Hydrogen

A large amount of CO2and H2exists in the shift gas of synthetic ammonia and should be purified before synthesis process. This paper concentrates on the gas-liquid phase equilibrium of CO2and H2in liquid absorbent using physical absorption method. Herein, acetone and [BMIM]+[BF4]-were selected as the representatives of organic solvent and IL respectively.Solubility data of CO2in acetone,[BMIM]+[BF4]-, and their mixtures (20%,50%,80%) were measured at temperatures of (298.2,313.2and333.2) K and pressures up to6.0MPa, The gas and liquid composition were determined using the quantitative and the gravimetric method, respectively. The solubility of CO2follows the order of xw3=1.0<xw3=0.8<xw3=0.5<xw3=0.2<xw3=0.0, however, the magnitude of Henry’s constants follows the contrary order. It was found that the mixture of acetone and [BMIM]+[BF4]-can decreases the loss of volatile solvent in CO2absorption process at relatively lower temperature.Solubility of H2in acetone,[BMIM]+[BF4]-and their mixtures (20%, 50%,80%) were measured at313.2K and333.2K and pressures up to6MPa. The gas and liquid composition were determined using the quantitative and drainage gas-collecting method, respectively. The solubility of H2follows the order of xw3=1.0<xw3=0.8<xw3=0.5<xw3=0.2<xw3=0.0.However, the magnitude of Henry’s constants follows the contrary order. It was found that the mixtures of acetone and IL as an environmental friendly solvent combine both advantages. Both the inverse solubility of H2and the solubility difference between CO2and H2are beneficial for separating process and improving the selectivity.The experimental data were correlated using the PR EOS for the binary systems and the lever rule for the ternary systems. Thermodynamic parameters and solubility data obtained in this work can provide a data foundation for lab study and industry application.