Chromatographic study and molecular simulation on adsorption in supercritical fluid

In our previous work [2], chromatographic measurements were made for benzene, toluene and m-xylene at low surface coverages on molecular sieving carbon (MSG) in super critical CO2 at temperatures between 313K and 373K and pressures between 15MPa and 25MPa. These data were used to determine the adsorption equilibrium constant, K*, and the micropore diffusivity, D. In this work, the range of CO2 pressures was extended to include pressures below the critical pressure of CO2. It was found that the value of K* for benzene on MSC increased dramatically when the CO2 pressure was reduced below its critical pressure, while the value of D decreased. A molecular simulation was performed to predict K* values. Although these results did not match numerically, the trend in K* values was represented.