Application of MOSCED and UNIFAC to Screen Hydrophobic Solvents for Extraction of Hydrogen-Bonding Organics from Aqueous Solution

Abstract

Liquid-liquid extraction using hydrophobic extraction solvents is a technology well-suited to the removal of certain hydrogen-bonding organics from water or brine. Even when distillation is technically feasible, extraction might allow a significant reduction in energy consumption depending on the specific application. Various methods are available for estimating the partition ratio (K) to assess technical feasibility; however, these methods often provide only rough approximations because of the complexity of hydrogen-bonding interactions in solution. To better understand the application of the MOSCED and standard UNIFAC activity-coefficient prediction methods for screening extraction solvents, calculations were compared with K data for the extraction of propylene glycol n-propyl ether (PnP), a model hydrogen-bonding compound. Estimates of limiting activity coefficients for PnP dissolved in the organic phase (γ ∞ PnP,organic ) obtained using MOSCED and UNIFAC are shown to be highly correlated with K data for a variety of hydrophobic organic solvents, including various alcohols, ketones, ethers, chlorinated hydrocarbons, aromatics, and aliphatic hydrocarbons. This example demonstrates how MOSCED or UNIFAC can be used to quickly rank candidate solvents for this class of compounds. The methodology facilitates process synthesis and design efforts by reducing the number of experiments required to identify suitable solvents.

Optimization of Subcritical Fluid Extraction of Bioactive Compounds Using Hansen Solubility Parameters

“…Predictive approaches to ascertain the solubility of solutes in sub‐ and supercritical fluids include application of group contribution methods (Klopman and others 1992; Pinho and others 1994), UNIFAC models (Fornari and others 2008), MOSCED models (Frank and others 2007), AQUAFAC models (Myrdal and others 1992), and a number of semi‐empirical equations (Miller and Hawthorne 2000; Clifford and Hawthorne 2002; del Valle and others 2006). Although experimental procedures have been established to measure the solubility of various low molecular weight solutes in subcritical water conditions (Mathis and others 2004), problems arise in using these methods for molecularly complex and very polar solutes in hot pressurized water; due to their high cost and low thermo‐stability at high temperatures and pressures.…”

Computing MOSCED parameters of nonelectrolyte solids with electronic structure methods in SMD and SM8 continuum solvents

“…For Wilson's equation applied to a binary mixture, we have where Λ 12 and Λ 21 are adjustable parameters. References and compared the use of Wilson's equation and UNIQUAC for modeling solid–liquid equilibrium with MOSCED and support the use of Wilson's equation. We therefore exclusively use Wilson's equation in this study.…”

“…in reverse with reference data for the pure solid and an excess Gibbs free energy model (to capture the composition dependence of the activity coefficient) to estimate the infinite dilution activity coefficient. This approach was recently adopted to parameterize MOSCED for a wide range of nonelectrolyte solid solutes . However, this approach is limited for design applications as it is not truly predictive.…”

Predicting the Solubility of Nonelectrolyte Solids Using a Combination of Molecular Simulation with the Solubility Parameter Method MOSCED: Application to the Wastewater Contaminants Monuron, Diuron, Atrazine and Atenolol

“…In the present study we will use the solubility parameter method MOSCED [12,[19][20][21][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. The use of solubility parameter-based methods is advantageous because they allow one to not only predict phase behavior using a simple analytic equation, but they can help offer an explanation in terms of the responsible molecular-level interactions.…”