A novel equation of state (EOS) for prediction of solute solubility in supercritical carbon dioxide: Experimental determination and correlation

Abstract

Solubility data of organophosphorous metal extractants in supercritical fluids (SCF) are crucial for designing metal extraction processes. We have developed a new equation of state (EOS) based on virial equation including an untypical parameter as BP/RT, reduced temperature and pressure for prediction of solute solubility in supercritical carbon dioxide (SC CO 2 ). Solubility experimental data (solubility of tributylphosphate in SC CO 2 ) were correlated with the two cubic equations of state (EOS) models, namely the Peng-Robinson EOS (PR-EOS) and the Soave-Redlich-Kwong EOS (SRK-EOS), together with two adjustable parameter van der Waals mixing and combining rules and our proposed EOS. The AARD of our EOS is significantly lower than that obtained from the other EOS models. The proposed EOS presented more accurate correlation for solubility data in SC CO 2 . It can be employed to speed up the process of SCF applications in industry.Les données de solubilité d'extractants de métaux organo-phosphorés dans des fluides supercritiques (FSC) sont cruciales pour concevoir des processus d'extraction des métaux. Nous avons développé une nouvelleéquation d'état (ÉÉ) basée sur uneéquation d'état du viriel comprenant un paramètre atypique tel que la température et la pression réduite pour la prédiction de la solubilité du soluté dans du dioxyde de carbone supercritique. Les données expérimentales de solubilité (solubilité du phosphate de tributyle dans CO 2 SC) ontété corrélées avec les deux modèles d'équations d'état cubiques, soit l'ÉÉ Peng-Robinson (ÉÉ-PR) et l'ÉÉ Soave-Redlich-Kwong (ÉÉ-SRK), avec deux paramètres ajustables, les règles de mélange et de combinaison van der Waals et notreÉÉ proposée. L'AARD de notreÉÉ est significativement plus faible que celui obtenuà partir des autres modèles d'ÉÉ. L'ÉÉ proposée présentait une corrélation plus exacte pour les données de solubilité dans le CO 2 SC. Elle peutêtre employée pour accélérer les processus des applications de FSC dans l'industrie.

Fractional factorial design for the optimization of supercritical carbon dioxide extraction of La3+, Ce3+ and Sm3+ ions from a solid matrix using bis(2,4,4-trimethylpentyl)dithiophosphinic acid+tributylphosphate

“…In recent years, there has been increasing interest in extracting metal ions by supercritical fluid extraction (SFE). Compared with conventional solvent-extraction, SFE is relatively fast and selectivity-controlled (Liu et al, 2001;Erkey, 2000;Sunarso et al, 2009;Jafari Nejad et al, 2009;Jafari Nejad et al, in pressa, in press-b Lanthanide (Ln) elements and Ln compounds have a wide range of applications including uses in fluorescent materials, magnets, superconductors, lasers, ceramics, semiconductors, catalysts and thermal neutron absorbents. The relatively new applications in the electronic and other industries have resulted in a dramatically increased demand for Ln materials of high purity.…”

Solubility prediction of some disperse Azo dyes in supercritical carbon dioxide using equation of states (EOSs)

“…The reason of election third order polynomial versus M is the fitting of this equation all the experimental data with R 2 >0.99 (Mohebbi et al, 2007, Jafari Nejad et al 2009 …”

“…The critical temperature and pressure of carbon dioxide is relatively low (304 K and 73.7 bar, respectively) (Jafari Nejad et al, 2009) and one of the most environmentally acceptable solvents in use today, and textile processes using this solvent have many advantages when compared to conventional aqueous processes (Fasihi et al, 2004). Supercritical carbon dioxide gives an option avoiding water discharge, it is low in cost, nontoxic, and nonflammable, and the carbon dioxide can be recycled.…”

“…In this study, solubilites of three disperse Azo dyes, 4-(N,N-dimethylamino)-4'-nitroazobenzene (D 1 ), 4-(N,Ndiethylamino)-4'-nitroazobenzene (D 2 ) and Parared (D 3 ) (Fasihi et al, 2004) in supercritical carbon dioxide have been correlated with two equation of state; Peng-Robinson EOS (PR-EOS) together with two adjustable parameter van der Waals mixing and combining rules and new (M-factor) EOS (Jafari Nejad et al, 2009). As far we know, solubility data for these dyes never has been correlated using an equation of state (EOS).…”

“…models), or the Ziger-Eckert semi-empirical correlation. These models are based on simple error minimization using least-squares methods, and for the majority of them, there is no need to estimate and use critical and thermophysical properties of the involved solutes (Jafari Nejad et al, 2009.…”