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Reactive adsorption desulfurization over metal oxides adsorbents was carried out to remove the sulfur of real fluid catalytic cracking gasoline and model gasoline in a batch reactor at low pressures in the presence of hydrogen. The results show that Ni appearing after reduction and higher temperature leads to a significant improvement in the desulfurization ability of the adsorbents. When the initial concentration of thiophene in the model gasoline raised the sulfur, removal rate decreased while the adsorption capacity of the adsorbents increased and the maximum sulfur removal rate and sulfur adsorption capacity were 86.33% and 13.72 mg/g, respectively. [ABSTRACT FROM PUBLISHER]

The oxides adsorbent of NiO/ZnO-Al2O3-SiO2was prepared by a co-precipitation method. The adsorbent can be used for the desulfurization of thiophene inn-hexane as model gasoline. Conditions of the reactive adsorption desulfurization in model gasoline were studied. Adsorption kinetics were found to follow a pseudo-first-order better than pseudo-second-order model. Equilibrium isotherms for the adsorption of thiophene over metal oxides adsorbents were analyzed by Freundlich and Langmuir isotherm models using a non-linear regression method. Further, Langmuir isotherm represented the equilibrium adsorption data best at all temperatures. [ABSTRACT FROM AUTHOR]

The oxides adsorbent of NiO/ZnO-Al2O3-SiO2was prepared by a co-precipitation method. NiO/ZnO-SiO2-Al2O3is an effective adsorbent for reactive adsorption desulfurization of fluid catalytic cracking gasoline. The reaction conditions, such as reaction temperature, total pressure, weight hourly space velocity, and volume ratio of hydrogen to oil for desulfurization over NiO/ZnO-SiO2-Al2O3in a fixed-fluidized bed reactor were investigated. With the optimum conditions, the sulfur content of FCC gasoline can be decreased from 180 to 11.6 mg·L−1, and the loss of olefin content of gasoline product is 1.05%, the research octane number loss of gasoline product is only 1.3 unit. [ABSTRACT FROM PUBLISHER]

The selective oxidative desulfurization was conducted with a feedstock of model gasoline consisting of thiophene and n-octane in an H2O2·HCOOH oxidative system over a Ti-MCM-41 catalyst. The operations were designed by the orthogonal design method with an L9 (34) table. Experimental results show that the factors influencing the rate of desulfurization are reaction temperature, the reaction time, and the volume percent content of the hydrogen peroxide in order. Under the optimized operation conditions over Ti-MCM-41 catalyst: H2O2 volume fraction of 3% (v), reaction time of 40 min and reaction temperature of 50°C, the removal ratio of thiophene was 95.6%, and the gasoline yield was 98.7%. The activity of the catalyst has no dramatic deactivation after reusing it five times. In addition, the kinetics study indicates that this reaction is a pseudo first-order reaction with the activation energy of Ea = 40.18 kJ/mol. [ABSTRACT FROM PUBLISHER]

The physicochemical properties of hydrogenated diesel fuel and its fractions produced by hydro-refining, hydro-upgrading, and hydro-cracking were analyzed. The lubricity of diesel fuel and its fractions were measured by a high-frequency reciprocating rig. The relationships of lubricities between the fractions were discussed. The prediction model for the lubricity of hydrogenated diesel with a sulfur content below 200 μg/g was established by using the stepwise linear regression method. The coefficient, R, reached up to 0.981, and the relative error of the predicted value to the actual value was less than 7%. According to the coefficients of the prediction model, the lubricity of ultra-low sulfur diesel with high kinematics viscosity, high nitrogen content, and low cycloparaffins content under the condition of deep hydrogenation was relatively inferior. The model could well predict the lubricity of the ultra-low sulfur diesel fuel and hydro-fining diesel fuel. [ABSTRACT FROM AUTHOR]

A novel Mach-Zehnder modulation technique based on a 1×3 multimode interference coupler and three optical phase-modulator waveguides for the generation of optical single sideband (SSB) signals in the radio-over-fibre millimeter-wave system is proposed. Two of the three modulator arms are biased by the direct current (DC) voltage and modulated by the radio frequency (RF) signal in the same way as conventional SSB modulation method to produce optical RF signals, but the third one which can be named as 'dc arm' is only biased by DC to change the path of the optical carrier passing through it. The interference at the output of the triple-arm modulator happens at the optical carrier frequency, which makes the power of the optical carrier in the SSB signal controllable. Optimised modulation depth between the sideband component and the carrier of the generated SSB signal could be obtained by adjusting the bias voltage applied to the 'dc arm'. It is proposed and analysed that the novel technique could improve the sensitivity of the optical receiver significantly compared with the conventional SSB modulation scheme. [ABSTRACT FROM AUTHOR]

The cubic perovskite BaRuO3 has been synthesized under 18 GPa at 1,000°C. Rietveld refinement indicates that the new compound has a stretched Ru-O bond. The cubic perovskite BaRuO3 remains metallic to 4 K and exhibits a ferromagnetic transition at Tc = 60 K, which is significantly lower than the Tc ≈160 K for SrRuO3. The availability of cubic perovskite BaRuO3 not only makes it possible to map out the evolution of magnetism in the whole series of ARuO3 (A = Ca. Sr, Ba) as a function of the ionic size of the A-site fA, but also completes the polytypes of BaRuO3. Extension of the plot of Tc versus TA in perovskites ARuO3 (A = Ca, Sr. Ba) shows that Tc does not increase as the cubic structure is approached, but has a maximum for orthorhombic SrRuO3. Suppressing Tc by Ca and Ba doping in SrRuO3 is distinguished by sharply different magnetic susceptibilities x(T) of the paramagnetic phase. This distinction has been interpreted in the context of a Griffiths' phase on the (Ca Sr)RuO3 side and bandwidth broadening on the (Sr,Ba)RuO3 side. [ABSTRACT FROM AUTHOR]

Ultrafine and uniform TiO2 nanofibres were prepared by electrospinning. The morphology of the nanofibres was characterised by field emission scanning electron microscopy, which showed that the nanofibres were composed of ultrasmall nanoparticles. The structure was characterised by X-ray diffraction and resonant Raman spectrum. The optical properties of the nanofibres were characterised by photoluminescence spectrum and ultraviolet visible spectrum. The results showed that anatase phase of TiO2 formed with the nanofibres annealed at 450°C for 3 h and showed good optical characteristics. [ABSTRACT FROM AUTHOR]