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Vapor pressures for the main component of the biodiesel – methyl oleate were measured by using the static method. For this purpose, a new setup for vapor pressure measurements in the range (0.1 to 1000) Pa and the elevated temperatures up to 450 K has been designed and tested using the reference materials benzoic acid and naphthalene. Absolute vapor pressures and sublimation (vaporization) enthalpies for the tested compounds were in a good agreement with the most reliable literature data. [ABSTRACT FROM AUTHOR]

The absolute vapor pressures over the solid and liquid 2-biphenylmethanol and 4-biphenylmethanol were measured using the transpiration method. The standard molar enthalpies of vaporization/sublimation were derived from the temperature dependence of vapor pressures. The standard molar enthalpy of fusion of 2-biphenylmethanol was measured using DSC. The available data on solid-gas, liquid-gas and solid-liquid phase transitions available in the literature have been collected, combined with own experimental results and evaluated using the structure-property relationships and quantum-chemical calculations. The high-level G3MP2 and G4 quantum-chemical methods were used to establish consistency of the experimental and theoretical results. Conformational analysis of 2-biphenylmethanol showed the possible presence of a hydrogen bond between the hydroxyl group and the aromatic ring. The strength of the intramolecular hydrogen bonding in 2-biphenylmethanol and 4-biphenylmethanol was assessed from thermochemistry and quantum-chemical calculations. [ABSTRACT FROM AUTHOR]

MoS2/Al2O3 and NiMoS2/Al2O3 catalysts were prepared by incipient wetness impregnation of alumina using aqueous solutions of 12-molybdophosphoric heteropolyacid and nickel citrate. Unsupported catalysts were prepared by etching a support made from MoS2/Al2O3 using hydrofluoric acid (Et-MoS2) and thermal decomposition of aluminum tetrathiomolybdate (Ref-MoS2). The activity of the catalysts in hydrodeoxygenation decreases in the series NiMoS2/Al2O3 = Et-MoS2 > MoS2/Al2O3 > Ref-NiS2. On the other hand, the selectivity relative hydrogenation of oleic acid has a different order: Et-MoS2 > MoS2/Al2O3 > Ref-MoS2 > NiMoS2/Al2O3. The unsupported Et-MoS2 catalyst has similar activity to NiMoS2/Al2O3 in hydrodeoxygenation and the highest selectivity, which indicates virtually completion of the hydrodeoxygenation reaction through a hydrogenation pathway without the formation of CO or CO2. These gases display strong inhibiting properties and have a detrimental eject on the environment. [ABSTRACT FROM AUTHOR]

Pt/Sup catalysts with SiO2, MCM-48, and Al2O3 supports (Sup) were prepared. The catalysts were studied by methods of low-temperature nitrogen adsorption, temperature-programmed reduction, and high-resolution transmission electron microscopy. The kinetic characteristics of hydrogenation of biphenyl and diphenylmethane taken separately and of their eutectic mixture were studied on a flow-through catalytic installation at temperatures of 150–170°С, pressure of 4 MPa, liquid hourly space velocity (LHSV) of 5–15 h–1, and hydrogen/feed ratio of 500 m3n.c./m3. A biphenyl–diphenylmethane eutectic mixture (weight ratio 35 : 65) was used as a model mixture. According to the data obtained, the catalyst activity decreases in the order Pt/MCM-48 > Pt/Al2O3 > Pt/SiO2. The use of mesostructured silicate MCM-48 as a support allows the dispersity of the active phase to be increased compared to the traditional SiO2 and Al2O3, which enhances the catalyst activity in hydrogenation of biphenyl and diphenylmethane. [ABSTRACT FROM AUTHOR]

Extraction of undesirable components from light catalytic cracking gasoil with N-methylpyrrolidone was studied. Extraction conditions were chosen, and the influence of the solvent to feed ratio on the process results was determined. Low solvent to feed ratios are favorable for obtaining highly concentrated extracts for the subsequent production of a liquid organic hydrogen carrier from them. The solvent to feed ratio of 0.75 : 1.00 can be recommended for obtaining a high-density jet fuel component. [ABSTRACT FROM AUTHOR]

Pt catalysts supported on the commonly used supports Al2O3, SiO2 and on mesostructured silicates SBA-15 and MCM-48 were examined in the dehydrogenation of decalin, that is the promising liquid organic hydrogen carrier (LOHC). Synthesized catalysts were studied by low-temperature nitrogen adsorption, temperature programmed reduction, high-resolution transmission electron microscopy. The catalysts are characterized by various dispersion of platinum. The activity of catalysts in decalin dehydrogenation decreases in the following order Pt/MCM-48 > Pt/SBA-15 > Pt/SiO2 > Pt/Al2O3. Pt/MCM-48 catalyst allows to release hydrogen in the decalin amount of 5.7 wt% and can be considered the promising LOHC hydrogen storage technology. [ABSTRACT FROM AUTHOR]

Supported CoMoS and NiWS catalysts were synthesized on the basis of an Al2O3—SAPO-11 composite support. The acid and texture characteristics of the thus synthesized materials were examined. The morphologies of the active sulfide phase of the catalysts were compared. The kinetic properties of the supported sulfide catalysts in the reaction of hydroisomerization of n-hexadecane and in the hydroprocessing of the diesel fraction were examined. It was shown that it is possible to obtain hydrogenates with improved low-temperature properties in the presence of supported sulfide catalysts containing no noble metals. [ABSTRACT FROM AUTHOR]

Ni/Sup catalysts were prepared, where SBA-15, γ-Al2O3, SiO2 were used as supports (Sup). The synthesized catalysts were investigated by the methods of low-temperature nitrogen adsorption, temperatureprogrammed reduction (TPR), and high-resolution transmission electron microscopy. The catalytic properties of the prepared catalysts were tested in liquid phase hydrogenation of biphenyl under conditions of a flow installation at temperatures of 60-100°C, pressure of 4 MPa, volumetric feed rate of 4-10 h-1 and H2: feed ratio of 1500 nM.. A 1 wt % solution of biphenyl in heptane, as a model mixture, was used. It has been established that the activity of nickel hydrogenation catalysts depends on the nickel content and the type of support. The activity of supported nickel catalysts decreases in the series Ni-12/SBA-15 > Ni-12/SiO2 >> Ni-12/Al2O3. The kinetic characteristics of the biphenyl hydrogenation reaction were determined: the rate constants and activation energy for the hydrogenation of the first and second aromatic rings of the substrate molecule. [ABSTRACT FROM AUTHOR]

A series of catalysts have been synthesized Ni-Mo-W/P-Al2O3 with different Mo: W ratios (a sample without W, Mo: W = 2: 1, Mo: W = 1: 1, Mo: W = 1: 2, and a sample without Мо) and a concentration of P2O5 in a support of 0.5 wt %. Heteropoly acids H3PMo12O40 · nH2O and H3PW12O40 · nH2O and nickel citrate were precursors of the active phase. High-resolution transmission electron microscopy and X-ray photoelectron spectroscopy were used to study the surface of the sulfide phase of the samples. Their catalytic activity was estimated in the reactions of dibenzothiophene hydrodesulfurization and naphthalene hydrogenation. A catalyst with the ratio Mo: W = 1: 1 showed the highest activity, and was characterized by the maximum concentration of atomic groups Ni-Mo-W-S, Mo-S, and W-S. [ABSTRACT FROM AUTHOR]

A series of NiMoW/P-Al2O3 catalysts with different Mo/W ratios (sample containing Mo only, Mo/W = 2: 1, Mo/W = 1: 1, Mo/W = 1: 2, and sample containing W only; P2O5 content of the support 2.0 wt %) were synthesized. The precursors of the active phase were the heteropoly acids H3PMo12O40∙nH2O and H3PW12O40∙nH2O, and also nickel citrate. The sulfide phase in the samples was studied by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy; the catalytic activity of the samples in dibenzothiophene hydrodesulfurization and naphthalene hydrogenation was determined. For the dibenzothiophene hydrogenolysis in the presence of quinoline and naphthalene (content in the model mixture, wt %: dibenzothiophene 0.3, naphthalene 1.5, and quinoline 0.5), kHDS for different samples is in the range 17.6-42.5 h-1 at 275°C and 24.6-45.9 h-1 at 300°C. For the naphthalene hydrogenation, kHYD varies from 0.79 to 1.89 h-1 at 275°C and from 0.91 to 3.78 h-1 at 300°C. The sample based on molybdenum showed the highest activity in hydrogenation and hydrodesulfurization. [ABSTRACT FROM AUTHOR]