V.A. Yakovlev

Nickel catalysts for the hydrodeoxygenation of biodiesel

A number of nickel and nickel-copper catalysts for the hydrodeoxygenation of fatty acid esters (biodiesel) were studied. The CeO2 and ZrO2 oxides and the CeO2-ZrO2 binary system were used as supports. The Ni-Cu/CeO2-ZrO2 catalyst exhibited the highest activity; it allowed us to quantitatively convert biodiesel into linear alkanes under mild conditions (290–320°C, 1.0 MPa). It was found that the selectivity of the formation of the main product (heptadecane) was 70–80%. The main correlations between the nature of catalysts and their activity under conditions of the target reaction were determined using temperature-programmed reduction, X-ray diffraction analysis, and electron microscopy. It was hypothesized that the high activity of Ni-Cu/CeO2-ZrO2 in the test reaction can be explained by the presence of a Ni1 − xCux (x = 0.2–0.3) solid solution as a constituent of the active component of the catalyst.

Исследование полученных методом капельного формования сферических гранул CuO-Fe2O3-Al2O3 катализатора для процесса сжигания бурого угля в кипящем слое

A method of drop molding was suggested for preparation of spherical granules of CuO-Fe 2 O 3 -Al 2 O 3 catalysts. The catalysts were characterized using a set of physicochemical methods and tested for fluidized bed burning of brown coal. The influence of thermal treatment (700 and 800 °C) on the activity, strength and physicochemical properties of the spherical CuO-Fe 2 O 3 -Al 2 O 3 catalyst were studied. The prepared catalyst was shown highly active to oxidation of CO (competitive to that of the currently used industrial catalyst), high crushing and attrition mechanical strength (ca. 10–14 MPa of the minimal crushing strength and 15–23 MPa in average; attrition loss 0.8 % according to ASTM D-4058). Testing of the CuO-Fe 2 O 3 -Al 2 O 3 catalyst for the fluidized bed burning of brown coal demonstrated the attainability of high coal burnout (95 %) characteristic of the industrial catalysts (Shchkz-1, IC-12-73, IC-12-74A), the CO content in flue gas being 600 ppm that was lower of that observed with the industrial iron-containing catalyst IC-12-74A 3,000 ppm) and comparable with the catalyst IC-12-73 (700 ppm).

Kinetics of rapeseed oil transesterification over a heterogeneous barium-aluminum oxide catalyst with the methanol pressure taken into account

Use of heterogeneous catalysts in the synthesis of biodiesel from vegetable lipids via transesterification with alcohols has certain advantages over use of homogeneous catalysts. Commercialization of this process needs investigation of its kinetics. Here, we report, for the first time, the kinetics of transesterification of rapeseed oil with gaseous methanol over a heterogeneous catalyst with methanol partial pressure taken into account. Experiments have been carried out in a flow reactor with a fixed bed of a barium-aluminum oxide catalyst at 200°C and a methanol pressure of 0.1–2.5 MPa. Experimental data have been processed in terms of a simplified kinetic model involving one irreversible second-order reaction (first-order reaction with respect to both oil and methanol). Service life tests have been carried out for the catalyst calcined at 700°C.