Search

Hydrogenolysis of glycerol based on biomass is a possible route to obtain various valuable chemicals. Molecular hydrogen is a reactant in hydrogenolysis reactions. Optimizing hydrogen pressure can bring about a number of different benefits and other value added aspects to the process. In addition, hydrogen could also affect the catalyst surface and chemical characteristics which affect the catalyst activity. This study is focused on the influence of the pressure of hydrogen on the hydrogenolysis of glycerol using a 10Ni-30HSiW/α-Al 2 O 3. The catalysts of 10Ni-30HSiW/α-Al 2 O 3 were prepared using a wetness impregnation technique and the catalytic activity is tested in a batch reactor. The characterization of these catalysts were performed using different techniques such as NH 3 temperature programmed desorption (TPD), X-ray powder diffraction (XRD), Thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and Fourier transformed infrared spectroscopy (FT-IR). The study found that the hydrogen pressure influenced both the conversion of glycerol and the distribution of products. As the H 2 pressure increased, the selectivity to 1-propanol (1-PO) increased while the selectivities to acrolein, acetol and other products decrease. Interestingly the conversion of glycerol went through a maximum of 64.8% at 145 PSI of H 2 and decreased as the H 2 pressure increased. It was found that it is necessary to have high hydrogen pressure to maintain Ni in the metallic or zero oxidation state which accelerated the hydrogenation of acrolein to 1-PO and suppressed the formation of byproducts. However reduction of W6+ to a lower oxidation state (W4+) occurred under a high pressure of H 2 which reduces the acidity of the catalyst during the dehydration and decreased the conversion of glycerol. [Display omitted] • Molecular hydrogen is an important reactant in hydrogenolysis of glycerol. • Acidity plays an important role for the dehydration. • Ni plays an important role for the hydrogenation. • Hydrogen does not only affect the product distribution but it also affects the glycerol conversion owing to changes in the oxidation states of Ni and W in the catalyst. • High hydrogen pressure is required to maintain Ni in the metallic or zero oxidation state. • High hydrogen pressure reduce the acidity of the catalyst due to the reduction of W6+ to a lower oxidation state (W4+). [ABSTRACT FROM AUTHOR]

The solubilities of CO2 in solvent poly(ethylene glycols) (PEGs) with molecular weights of 150, 200, 300, and 400 were measured over the range of pressure from (100 to 1200) kPa and temperature from (303.15 to 333.15) K. Henry's constant was obtained by linear fitting of the experimental data, and thermodynamic properties of solutions were calculated from the correlation of Henry's constant. It indicates that the solubility of CO2 increases with increasing molecular weights of PEGs. Henry's constant based on mole fraction and the molality of CO2 in PEG400 vary from (4.78 to 7.09) MPa and (1.56 to 2.48) MPa·kg·mol–1 from (303.15 to 333.15) K, respectively. [ABSTRACT FROM AUTHOR]

Abstract: A palladium-impregnated La0.75Sr0.25Cr0.5Mn0.5O3−δ /yttria-stabilized zirconia (LSCM/YSZ) composite anode is investigated for the direct utilization of methane and ethanol fuels in solid oxide fuel cells (SOFCs). Impregnation of Pd nanoparticles significantly enhances the electrocatalytic activity of LSCM/YSZ composite anodes for the methane and ethanol electrooxidation reaction. At 800°C, the maximum power density is increased by two and eight times with methane and ethanol fuels, respectively, for a cell with the Pd-impregnated LSCM/YSZ composite anode, as compared with that using a pure LSCM/YSZ anode. No carbon deposition is observed during the reaction of methane and ethanol fuels on the Pd-impregnated LSCM/YSZ composite anode. The results show the promises of nanostructured Pd-impregnated LSCM/YSZ composites as effective anodes for direct methane and ethanol SOFCs. [Copyright &y& Elsevier]

Ionic liquid (IL) 1-octyl-3-methylimidazolium chloride was found to effectively intensify cyclohexanol oxidation and resulted in 100% conversion of cyclohexanol with 100% selectivity to cyclohexanone using hydrogen peroxide as an oxidant and WO3as a catalyst. The effect of the IL as a solvent is discussed with the support of COSMO-RS theory. [ABSTRACT FROM AUTHOR]