Joseph C. Mullins

Ternary phase equilibria for acetic acid-water mixtures with supercritical carbon dioxide

Abstract Ternary phase equilibrium data are presented for acetic acid-water mixtures with supercritical carbon dioxide at temperatures of 313 and 323 K and pressures of 73, 104 and 139 bar. Selectivities and distribution coefficients were obtained from these data and are also reported. Results indicate that supercritical carbon dioxide is not a suitable solvent for acetic acid-water separations. An experimental flow apparatus equipped with a view cell was used to obtain the experimental measurements. Limited phase equilibrium data for the binary systems water-carbon dioxide and acetic acid-carbon dioxide at 323 K and pressures from 56 to 177 bar are also presented.

Evaluation of methods for calculating liquid-liquid phase-splitting

Abstract The reliability and computational efficiency of various methods for calculating liquid-liquid phase-splitting were evaluated for use in three-phase distillation models. Each method was tested using several binary, ternary, and multicomponent systems that exhibit liquid-liquid immiscibility.

Solvent extraction of fatty acids from natural oils with liquid water at elevated temperatures and pressures.

The use of liquid water at elevated temperatures and pressures as an extractive solvent for separating mixtures of compounds which occur in natural oils has been studied. A southern pine tall oil and a distillate from the deodorization of soybean oil were extracted with liquid water at temperatures from 298 to 312°C and pressures between 103 and 121 bar. Results indicate that water can be used to extract fatty and resin acids from crude tall oil to obtain a product with a high acid content that produces less pitch during distillation. The process can also be used to extract fatty acids from vegetable oil deodorizer distillate.

Liquid-liquid equilibria for oleic acid-water mixtures at elevated temperatures and pressures

Abstract Liquid-liquid equilibrium compositions have been measured for the oleic acid-water system at temperatures from approximately 522 K to 589 K at pressures which averaged about 6 bar above the three-phase equilibrium pressure. The system has been found to exhibit Type II fluid phase behavior and exhibits an upper critical end point at approximately 590 K and 108 bar.

Phase equilibria at high pressures for the ethane-heptane and ethane-triethylaluminum systems

Abstract A continuous-flow apparatus was used to measure vapor-liquid phase equilibrium data for the ethane-heptane and ethane-triethylaluminum (TEA) systems. The apparatus indudes a view cell to observe phase behavior at equilibrium conditions. On-line remote control and datalogging capabilities were provided by computers. Experimental data for the ethane-heptane system were obtained at a temperature of 394 K and pressures from 55.1 to 87.9 bar. The phase compositions obtained for this system are in good agreement with those reported previously in the literature. The ethane-TEA system was studied along the four isotherms of 348, 373, 398, and 423 K, and at pressures from 55 to 147 bar. Equilibrium vapor- and liquid-phase compositions were obtained along each isotherm at selected pressures.

Vapor-liquid phase equilibrium at high pressures for the ethane-trinormalbutylaluminum and ethane-trinormalhexylaluminum systems

Abstract A continuous-flow apparatus was used to measure vapor-liquid phase equilibrium data for the ethane-trinormalbutylaluminum (TnBA) and ethane-trinormalhexylaluminum (TnHA) systems. The apparatus includes a view cell to observe phase behavior at equilibrium conditions. The ethane-heptane system was studied at 394 K and pressures from 41.4 to 82.7 bar to ensure the reliability of the apparatus for obtaining accurate vapor-liquid equilibrium data. On-line, homogeneous, vapor- and liquid-phase samples were obtained for analysis by gas chromatography. The phase compositions determined by analytical and gravimetric methods are in good agreement with those reported previously in the literature. The ethane-TnBA and ethane-TnHA systems were each studied along the three isotherms of 348, 373 and 398 K. The pressures ranged from 82.7 to 148.2 bar for the ethane-TnBA system and 89.6 to 175.1 bar for the ethane-TnHA system. Equilibrium vapor- and liquid-phase compositions were obtained along each isotherm at selected pressures by a gravimetric method. The phase equilibrium data were correlated and checked for internal consistency.

Fluid phase equilibria for the methyl chloride—water system

Abstract Azeotropic distillation is frequently used in the dehydration of organic—water systems to produce a completely dehydrated product. A basic requirement for the process is that the added solvent entrain, or azeotope, the water for removal as the distillate. The purpose of this study was to determine whether methyl chloride exhibits the necessary fluid phase behavior with water to be used as an entrainer solvent for the dehydration of organic—water mixtures. A flow apparatus was used to determine liquid—liquid, liquid—liquid—vapor and vapor—liquid equilibrium compositions for the methyl chloride—water system at 313.2 and 333.2 K. Pressure vs. composition diagrams have been constructed at these two temperatures, and indicate that the methyl chloride—water system does not exhibit the type of azeotropic behavior suitable for water entrainment.

High-pressure phase equilibria and thermodynamic modeling for binary systems of light paraffins and aluminum alkyls

Abstract A continuous-flow apparatus was used to measure vapor–liquid equilibrium data at 398 K for the propane–triethylaluminum (TEA) and propane–tributylaluminum (TBA) systems. The pressures ranged from 31.0 to 55.2 bar for the propane–TEA system and 44.8 to 58.3 bar for the propane–TBA system. Equilibrium vapor- and liquid-phase compositions were obtained at selected pressures by a gravimetric method. A thermodynamic model was developed to correlate the vapor–liquid equilibrium data for the ethane–TEA, ethane–TBA, and ethane–trihexylaluminum (THA) systems that were previously measured and the propane–TEA and propane–TBA systems. Each system consists of the light paraffin and an equilibrium mixture of the aluminum alkyl monomer and dimer species. The Peng–Robinson cubic equation of state was used to calculate the equilibrium phase compositions. The necessary parameters for the equation of state were obtained from thermodynamic data of other investigators coupled with a group contribution method.