Search results for "liquid"
showing 10 items of 4351 documents
Vapor–liquid equilibria in the ternary system isobutyl alcohol+isobutyl acetate+butyl propionate and the binary systems isobutyl alcohol+butyl propio…
2005
Abstract Consistent vapor–liquid equilibrium (VLE) data at 101.3 kPa have been determined for the ternary system isobutyl alcohol (IBA) + isobutyl acetate (IBAc) + butyl propionate (BUP) and two constituent binary systems: IBA + BUP and IBAc + BUP. The IBA + BUP system show lightly positive deviation from Raoult's law and IBAc + BUP system exhibits no deviation from ideal behaviour. The activity coefficients of the solutions were correlated with its composition by the Wilson, NRTL, UNIQUAC models. The ternary system is very well predicted from binary interaction parameters. BUP eliminates the IBA–IBAc binary azeotrope. The change of phase equilibria behaviour is significant therefore this s…
Vapor–liquid equilibria in the systems 3-methylpentane+methyl 1,1-dimethylethyl ether and 3-methylpentane+methyl 1,1-dimethylpropyl ether at 101.3 kPa
1999
Abstract Pure-component vapor pressure of 3-methylpentane and vapor–liquid equilibrium (VLE) for the binary systems of 3-methylpentane with methyl 1,1-dimethylethyl ether (MTBE) and with methyl 1,1-dimethylpropyl ether (TAME) at 101.3 kPa have been measured. Both systems exhibit small positive deviations from ideality. They can be described as regular solutions and do not present azeotrope. The activity coefficients and boiling points of the solutions were correlated with its composition by Wilson, UNIQUAC, NRTL, and Wisniak–Tamir equations.
Vapor−Liquid Equilibria for the Binary Systems tert-Butyl Alcohol + Toluene, + Isooctane, and + Methylcyclohexane at 101.3 kPa
1998
Vapor-liquid equilibria were measured for binary systems of tert-butyl alcohol with toluene, isooctane, and methylcyclohexane at 101.3 kPa using a recirculating still. Experimental values of the vapor pressure of non-oxygenated pure components have been obtained. The accuracy of experimental measurements was ±0.01 K in temperature, ±0.01 kPa in pressure, and ±0.001 in mole fractions. The results are thermodynamically consistent according to the point-to-point consistency test. The data were correlated with five liquid-phase activity coefficients models (Margules, Van Laar, Wilson, NRTL, UNIQUAC).
Isobaric Vapor−Liquid Equilibria for Binary and Ternary Mixtures of Dipropyl Ether, 1-Propyl Alcohol, and Butyl Propionate
2006
Consistent vapor−liquid equilibrium (VLE) data at 101.3 kPa have been determined for the ternary system dipropyl ether + 1-propyl alcohol + butyl propionate and two constituent binary systems: dipropyl ether + butyl propionate and 1-propyl alcohol + butyl propionate. The dipropyl ether + butyl propionate system exhibits ideal behavior, and the 1-propyl alcohol + butyl propionate system shows positive deviations from Raoult's law. No additional azeotropes are present. The activity coefficients of the solutions were correlated with its composition by the Wilson, NRTL, and UNIQUAC models. The ternary system is well-predicted from binary interaction parameters. Butyl propionate breaks the dipr…
Phase Equilibrium for the Esterification Reaction of Acetic Acid + Butan-1-ol at 101.3 kPa
2007
In this work, the thermodynamic behavior of catalytic esterification reaction equilibrium and vapor–liquid equilibria (VLE) for the quaternary reactive system acetic acid + butan-1-ol + butyl acetate + water and constituent binary systems acetic acid + butyl acetate, butan-1-ol + butyl acetate, and butan-1-ol + water have been determined at 101.3 kPa, and liquid–liquid equilibria (LLE) of the binary system butan-1-ol + water have also been determined. The esterification reaction rate of the acetic acid and butan-1-ol mixture is very slow. So, in this study, p-toluenesulfonic acid was selected as the catalyst to accelerate the chemical reaction. The measured VLE data were correlated by the N…
1-Ethyl-3-methylimidazolium Dicyanamide as a Very Efficient Entrainer for the Extractive Distillation of the Acetone + Methanol System
2012
Isobaric vapor–liquid equilibria (VLE) for the ternary system acetone + methanol +1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]) as well as the two solvent + IL binary systems have been obtained at 100 kPa using a recirculating still. The addition of [emim][DCA] to the solvent mixture produced a salting-out effect greater than that produced by other ionic liquids, showing that this ionic liquid is, until now, the best IL tested as an entrainer for the extractive distillation of the acetone + methanol mixtures, causing the azeotrope to disappear for an ionic liquid mole fraction as low as 0.031, at 100 kPa. This behavior can be explained on the basis of the influence of the IL concent…
Phase Equilibria Involved in Extractive Distillation of Dipropyl Ether + 1-Propyl Alcohol Using N,N-Dimethylformamide as Entrainer
2007
Consistent vapor−liquid equilibrium data for the binary and ternary systems dipropyl ether (1) + 1-propyl alcohol (2) + N,N-dimethylformamide (3) are reported at 101.3 kPa. The results indicate that dipropyl ether (1) + N,N-dimethylformamide (3) system exhibits a positive deviation from ideal behavior and that 1-propyl alcohol (2) + N,N-dimethylformamide (3) system deviates negatively from ideality. The activity coefficients of the solutions were correlated by the Wilson, NRTL, and UNIQUAC models. It is shown that these models allow a very good prediction of the phase equilibrium of the ternary system using the pertinent parameters of the binary systems. In addition, the Wisniak−Tamir relat…
Vapor−Liquid Equilibria for the Binary Systems Isobutanol with m-Xylene, o-Xylene and p-Xylene at 101.3 kPa
1999
Vapor−liquid equilibria were measured for binary systems of isobutanol with m-xylene, o-xylene, and p-xylene at 101.3 kPa using a recirculating still. The accuracy of experimental measurements was ±0.1 K in temperature, ±0.01 kPa in pressure, and ±0.001 in mole fraction. The results were determined to be thermodynamically consistent according to the point-to-point consistency and Wisniak tests. All the systems show moderate positive deviations from ideality. The data were correlated with five liquid-phase activity coefficient models (Margules, Van Laar, Wilson, NRTL, UNIQUAC).
Isobaric vapor–liquid equilibria for the binary systems isobutyl alcohol+isobutyl acetate and tert-butyl alcohol+tert-butyl acetate at 20 and 101.3kPa
2005
Abstract New consistent vapor–liquid equilibrium data for the binary systems isobutyl alcohol (IBA) + isobutyl acetate (IBAc) and tert-butyl alcohol (TBA) + tert-butyl acetate (TBAc) are reported at 20 and 101.3 kPa. The IBA + IBAc system, which deviates positively from ideal behavior, can be described as symmetric solution and presents azeotrope at both pressures. The TBA + TBAc system shows positive deviations from ideal behavior and presents azeotrope only at 20 kPa. The activity coefficients and boiling points of the solutions were correlated with their composition by the Wilson, UNIQUAC, NRTL and Wisniak–Tamir equations.
Estimating the size of the loan sharking market in Italy
2014
In the current economic crisis, the risk is so high that entrepreneurs, commercial activities and even families may turn to the illegal market to obtain liquidity. This article proposes an estimate of the size of the usury credit market in Italy. The estimate is based on the assumption, provided by Guiso1, that before coming to a moneylender the borrower seeks to obtain credit through official channels. The results of our estimates confirm the seriousness of the problem, but provide much lower data than those reported periodically by the media. It is estimated that 372,000 economic activities may have been potentially involved in the usury market in 2012. The volume of loans disbursed in th…