Chemical complexing agents for enhanced solubilities in supercritical fluid carbon dioxide

Abstract

The effect of the strong Lewis base tri-n-butyl phosphate (TBP) on the solubility of benzoic acid and hydroquinone (HQ) in supercritical fluid carbon dioxide is reported. TBP is shown to be a much stronger cosolvent for these solutes than methanol. The principles of chemical reaction equilibria are combined with the Peng-Robinson equation of state in order to model these results. The performance of this chemical model is compared to that of a recently developed density-dependent local composition (DDLC) model