Investigation of Adsorption On MSC5A in Supercritical CO2 – Chromatography and Monte Calro Simulation –

 Chromatographic measurements were made for the adsorption of benzene or toluene on molecular sieving carbon (MSC) in supercritical fluid CO₂ mixed with organics. Supercritical chromatograph packed with MSC was used to detect pulse responses of organics. Adsorption equilibria and adsorption dynamics parameters for organics and CO₂ were obtained by moment analysis of the response peaks. Dependences of adsorption equilibrium constants, K*, and micropore diffusivity, D, on the supercritical CO₂ density were examined. To use Markham-Benton equation for obtaining the saturation adsorption amount, the adsorption isotherms was carried out the curve fitting method of least squares by the solver.

Fig.1. Experimental apparatus

 Molecular simulation of multicomponent adsorption equilibria was performed, and compared the simulation results with experimental results. Simulation software is Materials Studio (Version5.5) made by MSI. The Grand Caronical Monte Carlo method (under constant chemical potential (΅), volume (V), and temperature (T)) was used to get the equilibrium amount adsorbed. The purpose of performing simulation is to capture visually the adsorption phenomenon and to elucidate an adsorption mechanism on the molecule level. So, we created Pseudo activated carbon sub-micropore model (MSC68-test021 model) as adsorbent. By performing molecular simulation, it is obtained average loading [molecular/cell] and is possible to determine the amount adsorbed therefrom.