Measurements and Correlations of Liquid-liquid-Equilibria of the Mixtures Consisting of Ethanol, Water, Pentane, Hexane, and Cyclohexane (original) (raw)
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The Open Thermodynamics Journal, 2010
In this study, the liquid-liquid equilibria of the mixtures consisted of ethanol, water, and the main components of gasoline fuel: pentane, hexane, and cyclohexane were experimentally determined. This study is related to the phase behavior when water in atmosphere is absorbed into ethanol + gasoline fuel (gasohol) and then possibly separates into two liquid phases in an automobile fuel tank or an underground storage tank. The liquid-liquid equilibria in this study include three ternary systems: ethanol + water + pentane, ethanol + water + hexane, and ethanol + water + cyclohexane; three quaternary systems: ethanol + water + pentane + hexane, ethanol + water + pentane + cyclohexane, and ethanol + water + hexane + cyclohexane; one quinary system: ethanol + water + pentane + hexane + cyclohexane. The present experiments were conducted at 293.15, 303.15, and 308.15 K, and the experimental data were collected and some were compared to that available in literature, and finally all data were correlated with the UNIQUAC activity coefficient model.
Liquid-Liquid Equilibria of Fuel Oxygenate + Water + Hydrocarbon Mixtures. 2
Journal of Chemical & Engineering Data, 1995
The liquid-liquid equilibria of water + n-decane, water + n-hexadecane, and water + methylcyclohexane have been measured separately with the two oxygenates 2-methoxy-2-methylbutane (tertiary amyl methyl ether or TAME) and 2-methyl-2-butanol (tertiary amyl alcohol or TAOH) a t 25 "C. All of these systems exhibit type 2 liquid-liqud phase diagrams, though the shapes of the diagrams for the TAME and TAOH systems are quite different because of the much higher solubility of water in TAOH than TAME. One of the observations from our experimental data is that the addition of either TAME or TAOH to a hydrocarbon + water mixture results in an increased water solubility in the hydrocarbon phase and a decreased hydrocarbon solubility in the aqueous phase. This observation may be important when both the water pollution potential of possible gasoline reformulations and the sensitivity of the gasoline to water are assessed. We have found that the general features of the liquid-liquid phase diagrams can be accurately correlated with either the NRTL or UNIQUAC model, though some of the high dilution concentrations are incorrectly described. Finally, the liquid-liquid UNIFAC model leads to qualitatively correct predictions for the liquid-liquid equilibria of the systems studied.
TEMPERATURE INFLUENCE ON PHASE STABILITY OF ETHANOL- GASOLINE MIXTURES
The article investigates phase stability of ethanol-gasoline mixtures depending on their composition, water concentration in ethanol and ethanol-gasoline mixture and temperature. There have been determined the perfect functioning conditions of spark ignition engines fueled with ethanol-gasoline mixtures.
Currently, the atmospheric pollution has become a major problem leading to global warming, air-borne diseases etc. In order to find a suitable solution to this problem, the entire world is now switching to the alternatives. The thermo-physical properties vary for the alternatives and in order to use these, it is very essential to study their variation. In this paper, properties of ethanol and gasoline are calculated by mathematical methods and their values and trends are used to predict their behaviour. Ethanol has a problem of cold-start and smoother flow; thus it is essential to study its behaviour throughout its path from fuel tank to the intake manifold. The temperature may vary roughly around 20 to 1000 C along its path as quoted by some research papers;thus this temperature range was chosen for the study. The viscosity was found to decrease slowly with temperature for ethanol than gasoline indicating poor fluidity. The values for density and thermal conductivity were found to be higher for ethanol when compared to gasoline. In addition to that, the lower specific heat of ethanol indicates its potential to suppress the problems associated with cold-start but only to minimal extent.
Isobaric Vapor-Liquid Equilibria of Gasoline Additives Systems At 101.3 kPa
uotechnology.edu.iq
In this study, isobaric vapor-liquid equilibrium of gasoline additives for three ternary systems: "MTBE + Ethanol + 2-Methyl-2-propanol", "Ethanol + 2-Methyl-2-propanol + Octane", and "MTBE + Ethanol + Octane" at 101.3kPa are studied. Furthermore three binary systems: "ethanol + 2-Methyl-2-propanol", "MTBE + Ethanol", and "MTBE + Octane" at 101.3 kPa have been studied.
Vapor-liquid equilibria of hydrocarbons and fuel oxygenates. 2
Journal of Chemical & Engineering Data, 1993
Vapor-liquid equilibrium data for methyl tert-butyl ether (MTBE) + 1-heptene, MTBE + four-component gasoline prototype, ethanol + four-component gasoline prototype, and separately MTBE and ethanol with the Autotoil Air Quality Improvement Research Gasoline Blend A are reported. Small additions of MTBE have a very small effect on the total equilibrium pressure of this gasoline blend, and at most temperatures will decrease this pressure. In contrast, small additions of ethanol to this gasoline blend result in a significant increase in the equilibrium pressure at all temperatures. Analysis shows that the vapor-liquid equilibrium data for the MTBE-containing systems are easily correlated using a modified Peng-Robinson equation of state with conventional van der Waals one-fluid mixing rules. Data for mixtures containing ethanol cannot be accurately correlated in this way.
Physiochemical Property Characterization of Hydrous and Anhydrous Ethanol Blended Gasoline
Industrial & Engineering Chemistry Research, 2018
Water removal during the production of bio-ethanol is highly energy intensive. At the azeotropic point, the mixture can no longer be separated via fractional distillation, so expensive and energy intensive methods are required for further purification. Hence, there is an interest in using hydrous ethanol at the azeotropic point to improve the energy balance of ethanol fuel production. Currently there is a lack of available thermophysical property data for hydrous ethanol gasoline fuel blends. These data are important to understand the effect of water on critical fuel properties and to evaluate the potential of using hydrous ethanol fuels in conventional and optimized spark ignition engines. In this study, gasoline was blended with 10, 15, and 30 vol% of anhydrous and hydrous ethanol. The distillation curve, Reid vapor pressure, vapor lock protection potential, viscosity, density, haze and phase separation points, and lower heating value were measured for each blend and the results were compared to ASTM D4814, the standard specification for automotive spark ignition engine fuels. The majority of the properties measured for the low-and mid-level hydrous ethanol blends are not significantly different from those of the corresponding anhydrous ethanol blends. The only differences observed between the hydrous and anhydrous fuels were in viscosity and phase separation. The viscosity increased as the total water content increased, whereas the phase separation temperatures decreased with an increasing hydrous ethanol fraction. The results of this study suggest that hydrous ethanol blends may have the potential to be used in current internal combustion engines as a drop-in fuel and in future engine designs tuned to operate on fuels with high levels of ethanol.
International Journal of Energy and Environmental Engineering, 2014
Lysimeter experiments were conducted to compare the vapour phase transport of 20 % ethanol-and butanol-blended gasoline (E20 and B20) compounds in soils using the unblended gasoline (UG) compounds as the standard. Sand containing approximately 0 and 5 % organic matter (0 %f om and 5 %f om) was used to simulate the vadose zone. The 5 %f om soil promoted higher vapour phase transport of compounds than the 0 %f om soil due to its higher porosity, hence, was used to compare the transport to the groundwater zone of the different gasoline blends. The addition of 20 % alcohol by volume to gasoline reduced the retentive capability of the soil for gasoline compound vapours and thus resulted in greater downward transport and higher accumulation of gasoline compounds in the groundwater zone. The transport of gasoline compounds from the vadose zone to the groundwater zone was found to be in the order of E20 [ B20 [ UG, indicating that the risk of groundwater contamination with gasoline compounds after a spill or leak is more likely to be greater for ethanolblended gasoline compared with butanol-blended gasoline.
Iranian Journal of Chemistry & Chemical Engineering-international English Edition, 2009
The determination region of solubility of methanol with gasoline of high aromatic content was investigated experimentally at temperature of 288.2 K. A type 1 liquid-liquid phase diagram was obtained for this ternary system. These results were correlated simultaneously by the UNIQUAC model. The values of the interaction parameters between each pair of components in the system were obtained for the UNIQUAC model using the experimental result. The root mean square deviation (RMSD) between the observed and calculated mole percents was 3.57 % for methylcyclohexane + methanol + ethylbenzene. The mutual solubility of methylcyclohexane and ethylbenzene was also investigated by the addition of methanol at 288.2 K.