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[en] Full text: A probabale stage by stage scheme of mechanism of the reaction of vapor phase dehydration of butanol-2 and pentanol-2 at the zeolite catalyst NaY with due regard of isomer composition of olefmic has been suggested. Theoretically grounded kinetic model of the process has been worked up and the values of its kinetic parameters determined
[en] Highlights: • Fuel’s ignition and combustion characteristics are measured by different method. • Diesel blends containing 20% and 40% n-pentanol are examined. • D60P40 advances ignition phase over D80P20 under low oxygen content conditions. • Flame luminosity is reduced with the increase of pentanol ratio in most conditions. • Pentanol could significantly accelerate soot oxidation under all conditions. - Abstract: Pentanol is considered as one of the most promising alternative biofuels due to its excellent physicochemical properties. The objective of this work was to compare the ignition and combustion characteristics of different n-pentanol/diesel blends in an optical constant volume combustion chamber. The tested fuels included 20% (D80P20) and 40% (D60P40) of n-pentanol blended with diesel in volume, and pure diesel (D100). Broadband chemiluminescence technique was used to measure the timing and location of spray ignition. A high-speed CCD camera with two ND8 dimmer lenses was used to capture the incandescence radiated from the soot particles during combustion. A wide range of experimental conditions was investigated. The ambient temperature ranged from 800 K to 1200 K and the oxygen concentration ranging from 10% to 21%, covering both the conventional and low temperature combustion regimes. The results show that pure diesel has shorter ignition delay and distance comparing to pentanol blends. A larger blending proportion of pentanol D60P40 advances the ignition phase more than the D80P20 in low oxygen concentration conditions. Due to the fuel-borne oxygen and the dilution effect, the natural flame luminosity is reduced significantly with the increase of pentanol ratio in most conditions except under the intermediate temperature region of 1000 K. In that condition, the shorter ignition delay and flame lift-off length of pentanol blends cause a slightly increase in the natural flame luminosity. The natural flame luminosity images showed that the oxygen-contained structure of pentanol could accelerate soot oxidation under all conditions. This indicates that pentanol blends could decrease final soot emissions in internal combustion engines.
[en] Anion exchange resins based on the copolymer of 4-vinylpyridine-divinylbenzene were synthesized in the presence of solvents. It was observed that the resins obtained with 8% divinylbenzene gave best chloride capacities. These resins were methylated to get strong base anion exchange resins for uranium hydrometallurgy with basic solution. The resin obtained with tertiary amyl alcohol and 8% divinylbenzene gave the best uranium adsorption capacity. This resin was compared with the commercial resin Dowex SBR-P which gave a lower capacity. The strong base and weak base chloride capacities and porosity data of this are reported. (author)
[en] Highlights: • Liquid equilibrium data of (water + BA + alcohols) systems were measured. • Experimental LLE data were correlated with NRTL and UNIQUAC models. • Distribution coefficients and separation factors were evaluated. -- Abstract: In this study, solubility and tie-line data of the (water + butyric acid + n-butyl alcohol or amyl alcohol) ternary systems were determined at T = (298.2, 308.2, and 318.2) K and p = 101.3 kPa for the first time. Due to the structural similarity, the tie-line data for (water + butyric acid + isoamyl alcohol) system were also measured and correlated at T = 298.2 K. The ternary systems investigated display type-1 behaviour of LLE. The cloud point method was used to measure the solubility data and the Karl-Fischer, acidimetric titration, and refractive index methods were used to determine the tie-line data. For each system, the experimental tie-line data were correlated using the UNIQUAC and NRTL models. The Othmer–Tobias and Hand correlations equations were used to establish the quality of the LLE data. Experimental distribution coefficients and separation factors were evaluated over the immiscibility regions
[en] Microgram amounts of plutonium are measured spectrophotometrically as the plutonium-chlorophosphonazo III complex after extraction into n-pentanol from 1.5 M HCl. The relative standard deviation is 1.5% for the range of 2.5 to 17.5 μg. The tolerance is excellent for many metals and nonmetals present in nuclear fuel-cycle materials. A preceding anion-exchange-column separation increases tolerance for certain metals and nonmetals
[en] The type and magnitude of interactions between diisobutyl ketone (DIBK) and a homologous series of 2-alkanols (2-propanol up to 2-pentanol) are studied in this paper using density and viscosity data. Studies have been carried out in a wide range of temperature (293.15 K to 323.15 K), atmospheric pressure, and in the entire range of composition. The calculated excess molar volumes of the above-mentioned systems are positive, and the viscosity deviations are negative. For the correlation of the density values of binary systems, the statistical association fluid theory (SAFT) and perturbed chain statistical association fluid theory (PC-SAFT) have been used, and the output of two models are compared by average absolute deviation. The results show that the PC-SAFT model is more efficient. Densities and viscosities reported for binary systems along with applied models are all novels, and so far no reports have been investigated in the scientific papers.
Graphic abstractPC-SAFT and SAFT models were applied to model the densities of binary mixtures containing Diisobutyl ketone and 2-alkanol at various temperatures. Results show that models provide satisfactory outcomes and PC-SAFT model produces better results. .
[en] Highlights: • Surface tension of non-ideal binary systems of alcohol/DMSO determined. • The surface tension data of binary mixtures were correlated with five equations. • The interaction energy values were calculated by using LWW model. • The U12 value shows different behavior for two systems with increasing temperature. - Abstract: Surface tension of binary mixtures of tert-butyl alcohol (TBA) and iso-amyl alcohol (IAA) with DMSO (dimethyl sulfoxide) were measured over the entire concentration range at pressure of 82.5 kPa at temperatures between (298.15 and 328.15) K. Correlating the surface tension and surface tension deviation of the above mentioned binary systems was performed with empirical and thermodynamic based models. The average relative error obtained from the comparison of experimental and calculated surface tension values for the two binary systems with five models at various temperatures is less than 2%. The effect of temperature on the interaction energy values in binary mixtures has been used to obtain information about solute structural effects on DMSO. Also, the experimental data were used to evaluate the nature and type of intermolecular interactions in binary mixtures