Solubility in Supercritical Carbon Dioxide: Importance of the Poynting Correction and Entrainer Effects

Abstract

Gibbs ensemble Monte Carlo simulations were used to investigate the effect of pressure and of entrainers on the solubility of low-volatility species in CO 2. Two entrainers were examined, n-octane and methanol, as well as two solutes, hexamethylbenzene and benzoic acid. For the three pressures studied (12, 20, and 28 MPa), the simulations demonstrate that the increase in the solubility with increasing pressure is mostly due to an increase in the solute's chemical potential (as expressed by the Poynting correction) and not due to an increase in the solvent strength of supercritical CO 2. The presence of an entrainer enhances solubility, particularly when the solute and entrainer can form hydrogen bonds. The solubility of benzoic acid is enhanced by an order of magnitude upon addition of methanol entrainer, whereas the enhancements are less than 2 for the other systems.

Monte Carlo simulations of phase behavior and microscopic structure for supercritical CO2 and thiophene mixtures

“…Molecular simulation has previously been applied successfully to determine solubility of naphthalene, benzoic acid, hydroxybenzoic acid, etc. in ScCO 2 [22][23][24][25]. Here, we attempt to study the thermodynamic properties in solution mixtures of thiophene and ScCO 2 and provide molecular level insights on the interactions between the thiophene and CO 2 in supercritical phase.…”

Driving Forces Controlling Host–Guest Recognition in Supercritical Carbon Dioxide Solvent

“…BEA has also been used to analyze the co‐solvent effect of molecules of different polarities . Through Monte Carlo simulations, the molecular nature of this effect has been studied . The solubility enhancement is larger when the co‐solvent has similar polarity compared with that of the solute.…”

Estimation of ginger bioactive compound solubilities in hot compressed water and enhancement with entrainer

“…The knowledge of 6-gingerol+water solute-solvent interaction gives a better understanding of the solvation phenomena and facilitates the improvement of the solubility of the solute in a given solvent. For instance, by introducing a small amount of co-solvent, such as ethanol, the solubility by the forming of hydrogen bonds of the solute and entrainer may be enhanced [44].…”

“…The solubilities of solutes were enhanced when the solutes and entrainer form the hydrogen bonds [44]. The effect of the entrainer may also expand the polarity range of the solvent, and, hence, influence the solute-solvent interaction and increase the solubility in the extraction process [23].…”