Structure solubility correlations: organic compounds and dense carbon dioxide binary systems

Abstract

The solubilities of several organic compounds in dense carbon dioxide (both liquid and supercritical) have been determined. Our data supplements earlier work by Francis. Based on these two sets of data, the structural features that either limit or enhance the solubility of different groups of compounds are identified. By use of this approach, some general structure-carbon dioxide solubility relationships have been developed and are illustrated by examples in the case of hydrocarbons, alcohols, phenols, aldehydes, ethers, esters, amines, and nitro compounds. These relationships can be used in qualitative predictions about the solubilities of substances in carbon dioxide; such information would be useful in enhanced oil recovery operations, supercritical fluid chromatography, and supercritical fluid extraction.

Tuning catalyst solubility in CO2by changing molar volume

“…When transesterification reaction rates are concerned, presumably, CO 2 addition to the mixture of methanol and triglyceride increases the mutual solubility of the reactants, and lowers the viscosity of the reaction medium (44Á46), which may act to enhance the rate of the reaction. As only 0.03% (w/v) glycerol is soluble in CO 2 (47), glycerol formed during reaction readily separates from the reaction mixture, driving the equilibrium forward. In the conventional process SFO, octane, and methanol form a biphasic medium leading to a much slower reaction.…”

Co-solvent Selection for Supercritical Fluid Extraction of Astaxanthin and Other Carotenoids from Penaeus monodon Waste

“…In this study, the ethanol helped to swell the pores of the biomass, which in turn improved the interaction of the SC-CO 2 with the cell. The high molecular weight of astaxanthin MW 596.8 slowed down its release in SC-CO 2 due to its low volatility 33 . Ethyl alcohol is also suitable to be applied as an entrainer for the extraction of the other high MW carotenoids 34,35 .…”

Transition Metal-Free Incorporation of CO2

“…[107] Transition Metal-Free Incorporation of CO 2 Sn compounds, such as dibutyltin oxide (Bu 2 SnO) and dibutyltin dimethoxide (Bu 2 Sn(OMe) 2 ), have been reported to be efficient catalysts for the carboxylation of methanol [110,111], glycol [112], glycerol [113], and 1,2-aminoalcohols into carbonates and 2-oxazolidinones, respectively. Taking the carboxylation of propylene glycol with CO 2 as an example, a plausible catalytic cycle is proposed as illustrated in Scheme 30.…”