HIGH-PRESSURE EQUILIBRIUM CELL FOR SOLUBILITY MEASUREMENTS IN SUPERCRITICAL FLUIDS

This paper describes the design, construction, and operation of an ultraviolet-visible light-transmission cell for high-pressure fluids. The cell can be operated at pressures as high as 70 MPa and at temperatures up to 100-degrees-C. This instrument was specifically designed to measure the solubility of solutes in supercritical fluids. The cell has an internal saturator and fluid circulator that are easy to remove and clean. The solubility of ferrocene in supercritical carbon dioxide was measured in the high-pressure cell described here. At 40-degrees-C, the mole fraction of ferrocene in carbon dioxide increased from 0.00005 to 0.0015 as the solvent density was increased from 5 to 17 mol/L.