High pressure flow gravimetric apparatus for supercritical fluid extraction studies

Abstract

An experimental apparatus has been developed for real time measurements of fluid–solid adsorption (or desorption) rates and equilibria at elevated pressures. In addition to controlling pressure and flow rates simultaneously, this setup is able to operate at higher flow rates than previously possible in supercritical fluid experiments. The system consists of a high pressure microbalance, two high pressure syringe pumps, and an absorbance detector. The microbalance enables the collection of data at a greater time resolution, resulting in a more accurate measurement of rate data. Because of the dual syringe pump design, there is no pressure drop in the system, making it possible to operate at a wide range of flow rates (at experimental conditions). The buoyancy force was measured with helium experiments, while the hydrodynamic forces were measured using a clean solid sample and supercritical carbon dioxide at different flow rates. It was found that the hydrodynamic force increased with flow rate as expected. The apparatus was tested by conducting two desorption experiments of phenol from activated carbon at 141±0.07 bar, 36.0±0.02 °C, and 0.47 ml/min (at experimental conditions). The amount of phenol removed was 16.4% and 18%, respectively, in the two runs which is consistent with previously published results and indicates the difficulty of regenerating activated carbon loaded with phenol.

High-Pressure Adsorption of CO2 on NaY Zeolite and Model Prediction of Adsorption Isotherms

“…Gravimetric Adsorption Apparatus. The adsorption apparatus, experimental procedure, and data rectification and analysis were as described previously, , with slight revisions. An OXY-Trap (AllTech) was added to further reduce the oxygen impurities in the CO 2 gas.…”

High‐resolution adsorption isotherms of supercritical carbon dioxide on activated carbon

“…small enough -2 mLrmin at experimental conditions , so Ž . hydrodynamic drag can be neglected Jwayyed et al, 1997 . The fluid delivered to the microbalance comes in contact with the adsorbent and the excess adsorption, measured as an increase in weight by the balance, is continuously recorded by a computer. Thus, as the pressure is incrementally increased from 0 to 20 MPa, a continuous adsorption isotherm can be obtained.…”

Pore Size Effects on the Sorption of Supercritical CO2 in Mesoporous CPG-10 Silica

“…For the purposes of site selection, long-term reservoir behavior prediction, and risk assessment, the interactions of supercritical CO 2 with porous solids need to be quantified. Gravimetric or volumetric sorption techniques have assessed the sorption of supercritical CO 2 onto coal and clays as a means of exploring the potential of large-scale storage of anthropogenic CO 2 in geological reservoirs. − Enhanced coalbed methane production using CO 2 has been studied in ref . Carbon sequestration in saline aquifers involves brine displacement, which can create dryout zones, accompanied by salt precipitation and changes in porosity and permeability. − Modeling of these very complex systems is crucial for our understanding but requires detailed knowledge of the individual fluid–fluid and fluid–solid interactions.…”