Vol 9, No 1 (2017)

Basic physicochemical and service properties inherent in middle distillate fractions from hydrocatalytic and thermodestructive processes are studied for one Russian refinery from the viewpoint of using them as potential components for low-viscous marine fuels (LMFs) with improved environmental and low-temperature properties. A laboratory-scale flow-through setup loaded with an industrial nickel–molybdenum catalyst is used for the hydrocracking of vacuum gasoils (with T_ebp ranging from 500 to 580°C) at 340–380°C and 15.0 MPa. The highest yield of the light hydrocracking gasoil (LHCG) is observed upon the processing of vacuum gasoil (T_ebp, 350–500°C) at 360°C, the highest cetane index (53 points) and the lowest sulfur content (7 ppm) being characteristic of the obtained LHCG. With heavier vacuum gasoil, the total yields of target distillates and the yield of LHCG decrease. In terms of physicochemical and service properties, the obtained LHGC is a high-quality component of LMFs. Comparative properties of the hydrorefined virgin diesel fraction, light gasoils obtained via catalytic cracking, slow coking, and the promising hydrocracking process are analyzed. The physicochemical, environmental, and main service properties inherent in the middle distillate fractions of secondary processes are determined depending on their hydrocarbon and nonhydrocarbon compositions, and on the content of key components. Based on these dependences, recommendations are made for the production of optimum low-viscous marine fuels with improved environmental and low-temperature properties.

Results from pilot tests of microspherical aluminochromium KDI-M catalyst mixed with IM-2201 in a large-scale unit (Nizhnekamskneftekhim) for iso-butane dehydrogenation are discussed. Compared to KDI catalyst, its modified analogue KDI-M is more active and selective; the optimized grain-size composition and mechanical strength ensures higher yields of iso-butylene and longer nonstop operation (up to 400 days) of the reactor unit.

The effect of the ruthenium promotion of Fischer–Tropsch (FT) cobalt–alumina catalysts on the temperature of catalyst activation reduction and catalytic properties in the FT process is studied. The addition of 0.2–1 wt % of ruthenium reduces the temperature of reduction activation from 500 to 330–350°C while preserving the catalytic activity and selectivity toward C₅₊ products in FT synthesis. FT ruthenium-promoted Co–Al catalysts are more selective toward higher hydrocarbons; the experimental value of parameter α_ASF of the distribution of paraffinic products for ruthenium-promoted catalysts is 0.93–0.94, allowing us to estimate the selectivity toward C₂₀₊ synthetic waxes to be 48 wt %, and the selectivity toward C₃₅₊ waxes to be 23 wt %. Ruthenium-promoted catalysts also exhibit high selectivity toward olefins.

A new type of catalyst based on microfiber supports with microfibers twined into looped threads (lemniscate) that in turn form a structured flexible stable and geometrically regular bulk bed permeable to a reaction flow and not requiring any additional structurial elements is described. Deep toluene oxidation experiments show that the proposed platinum lemniscate glass-fiber catalyst (LGFC) considerably surpasses (by 8–10 times and more) familiar geometric types of catalysts, microfiber and otherwise, in both the specific observed activity per unit active component mass and the ratio between the observed activity and the specific hydraulic resistance. The reason for its superiority is a uniquely high efficiency of mass transfer in the external diffusion region of reactions. Among the promising fields of application for the proposed systems are fast gasphase catalytic reactions, liquid-phase catalytic reactions, and complicated reaction processes, in which the selectivity and the yield of target products are sensitive to diffusion inhibition.

The effect of the temperature of WO₃/ZrO₂ support calcination in the range of 700–1000°C on the phase composition, acid, and catalytic properties of Pt/WO₃/ZrO₂ catalysts is studied. Using ammonia TPD, it is found that calcination in the temperature range of 850–950°C results in the formation of strong acid sites that increase the yield of the target products of the reaction of n-heptane isomerization: high octane di- and trimethylsubstituted isomers. DRIFT is used to determine the role of catalyst calcination in an air flow plays in the formation of charged platinum atoms, which results in higher catalyst activity.

In this study we discuss the properties of biocatalyst based on Geobacillus stearothermophilus G3 lipase immobilized on silica gel. Interesterification of sunflower oil and hydrogenated soybean oil (HSO) in a batch reaction was completed within 2 h, 10% biocatalyst (wt %), 70°С, and HSO: sunflower oil molar ratio of 1: 3. The physical and chemical parameters of reaction products were studied by HPLC-MS to access the composition of triacylglycerides and by slip melting point method. Biocatalyst has shown high operational stability. The estimated time of its operation in the oil mixture was 243 h that makes this catalyst promising for application in manufacturing of modified fats, including fats with high melting temperatures.

The possibility of using wheat bran as a feedstock for sugar production via biocatalytic conversion is demonstrated. The relatively low reactivity of this feedstock can be doubled or quadrupled by dry milling on an AGO-2S planetary mill activator. The maximum yield of reducing sugars, 68.6 g/L (initial substrate concentration, 100 g/L; glucose is the major component of the resulting sugars, 93–95%), is achieved when wheat bran milled for 7–10 min is subjected to bicatalytic conversion using the complex enzyme preparation (EP) of Penicillium verruculosum gaBG with cellulolytic, hemicellulolytic, and amylolytic activity at a gaBG dose of 60 mg/g (supplemented with F10 β-glucosidase EP, 40 units/g). Polysaccharides comprise 62.4% of the dry weight of the wheat bran; allowing for the water incorporated during enzymatic hydrolysis, the achieved yield is close to the theoretical figure (68.6 g/L) and there is virtually complete conversion of the wheat bran carbohydrates. Lengthening the duration of milling to 7–10 min considerably reduces the size of bran particles, lowers (by 28%) their ability to bind water, nearly doubles the content of water-soluble sugar, and increases (by 12.6%) the total content of soluble components, relative to the initial material.