Catalysts on resistive supports – thermostable metal alloy fechral (FeCrAl) and carborundum (silicon carbide SiC) – were studied in the reaction of methane pyrolysis into acetylene. Oxides (iron and chromium oxides, alumina, as well as zirconia and silica) as the active components were chosen corresponding to those occurred on the surface of heat-treated fechral alloy. The oxide supporting on carborundum results in an increase in the methane conversion compared to the conversion over initial carborundum, the maximal selectivity to acetylene being observed with ZrO₂/SiC and Al₂O₃/SiC. In contrast, supporting of these oxides on fechral results in a decrease in the activity and selectivity to acetylene (compared to those observed with the initial heat-treated fechral) but in widening the temperature range of the catalyst operation and in an increase in the stability in time. With carborundum, the latter parameters are independent of the oxide supporting. The studies of the initial supports (fechral and carborundum) and of the metal oxides supported thereon have led to assume that the high selectivity to acetylene is caused by the formation of carbon fibers on the catalyst surface, the fibers being preferably formed on the surface of alumina, zirconia and silica.

Principal regularities of vapor-phase dehydration of glycerin over a heterogeneous 0.5B₂O₃/γ-Al₂O₃ (BAO-1) catalyst were studied and a kinetic model of the process was suggested based on the data obtained using a differential reactor. The kinetic constants involved in the generalized mathematical models were estimated using the method of differential evolution based on the program package Mathematica 5.0. The activation energy of the target reaction was calculated to equal (50.18±0.11) kJ·mol^-1. The adequacy of the obtained equations was tested on the basis of Fisher's variance ratio. The suggested kinetic equations were used for determining optimal conditions of the glycerin dehydration process (process temperature 330 °C, inlet glycerin concentration 30 %, catalyst loading ratio 0.0338 L·h_cat ^-1·min^-1). The data obtained can be helpful in calculations for scaled-up facilities for acrolein production through glycerin dehydration.

Non-supported niockel-molybdenum and cobalt-molybdenum sulfide catalysts were prepared through in situ decomposition of water-soluble bimetal precursors in hydrocarbon feedstock. The precursors were nickel- and cobalt-molybdenum complexes with citric, oxalic, amber, glutaric and tartaric acids. The prepared sulfide catalysts were characterized using transmission electron microscopy and X-ray photoelectron spectroscopy. The catalyst activities to hydrogenation of bicyclic aromatic hydrocarbons and to hydrodesulfurization of dibenzothiophene were studied. The composition of the ‘precursor solution in hydrocarbon feedstock’ emulsion was established to influence the catalyst activity. The high activity was reached as soon as in an hour after the reaction started. The reactions under consideration were hydrogenation of mono-, di- and trimethylnaphthalenes, as well as hydrogenation of ethylnaphthalene. The optimal promoter:molybdenum ratio equal to 0.25 : 1 was determined. The catalyst activity was demonstrated not to decrease upon recirculation because of the absence of the negative effect of water (constituent of the emulsion) that oxidizes the catalyst surface. After the second cycle of the reaction, the catalyst particles are longer and bear more MoS₂ layers than the particles after the first cycle. XPS studies revealed that recirculation results in a decrease in the total oxygen content on the catalyst surface, in an increase in the metal proportion in the sulfide surrounding and sulfur in the sulfide state.

The influence of the treatment of alumina with organic acids (acetic, oxalic) on the dispersion, composition and catalytic behavior of platinum centers of reforming catalysts was studied. It was established that Pt/Ox-Al₂O₃ prepared using alumina treated with the oxalic acid solution is most active due to its considerable defect surface structure. The acid modifying resulting in the formation of charged platinum atoms was revealed to favor an increase in the catalyst activity.

The process of catalytic steam cracking (CSC) of heavy oil with high contents of sulfur (4.3 wt %) and high-boiling fractions (>500 °C) was studied in the presence of Mo- and Ni-containing nanodisperse catalysts under static conditions (autoclave) at 425 °C. Experimental studies of thermal and steam cracking, as well as of water-free catalytic cracking were carried out for comparison and identification of specific features of CSC. Dependencies of the composition and properties of the liquid and gaseous products on the process conditions, catalyst nature and the presence of water were determined. It was established that the application of Ni-catalysts for CSC causes an increase in the H : C ratio (1.69) in the liquid products against that of the other cracking processes, while the yields of coke and gaseous products increase that results in a decrease in the liquid product yield. With the Mo-catalyst, the produced low-viscous semisynthetic oil is characterized by a higher H : C ratio (1.70 wt %) and the lowest sulfur content (2.8 wt %) in the liquid products. XPS and HRTEM studies of the catalyst-containing solid residue (coke) revealed that in CSC nickel is as well-crystallized nanoparticles Ni₉S₈ of 15–40 nm in size, and molybdenum as two phases MoO₂ and MoS₂ at the ratio depending on the conditions of heavy oil transformation. The data obtained demonstrate that CSC is a promising process of upgrading heavy oil.

The influence of a catalytic additive – magnetic ferrospheres – on the product composition of cracking of natural bitumen from Ashal'chinskoe oilfield (4.6 wt % of fractions with IBP 200 °C) was studied. The reaction was achieved in an autoclave in the presence of a hydrogen donor (water). The addition of 10 wt % of ferrospheres was shown to favor the tar destruction and to increase the yield of light boiling fractions. The coke formation was decelerated during bitumen aquathermolysis under supercritical conditions. In aquathermolysis with ferrospheres at 500 °C, the yield of fractions IBP 360 °C increase by 12.5 %, while gas and coke yields decreased by 14.4 and 3.9 wt %, respectively, against the yields during bitumen cracking. The data on structure and group analysis of tars and asphaltenes indicate considerable destruction of the alkyl and naphthene species during aquathermolysis. Application of aquathermolysis allows heavy hydrocarbon feedstock to be processed using inexpensive and effective additives to improve considerably the conversion ratio.

The present work was aimed at scaling-up of the total cycle of bioethanol production from pretreated oat hulls using pilot facilities. The process of one-stage chemical pretreatment of the oat hulls with a diluted nitric acid solution at atmospheric pressure was scaled-up using a capacitive equipment (250 L). A total of hydrolyzed polysaccharides was 87.2 % in the resulting substrate. The process of enzymatic hydrolysis and ethanolic fermentation was successfully achieved in a 63 L capacitive equipment using commercially available enzymatic agents CelloLux-A and BrewZyme BGX and commercial strain of yeasts Saccharomyces сerevisiae VKPM Y-1693, the scaling ratio being 1 : 400. Bioethanol was synthesized at a high yield (17.9 dal/t). After rectification, the test sample meets standards of pure spirit of best quality from edible raw materials in respect of the weight ratios of aldehydes, esters and methanol.

Actinobacterial strain Dietzia maris IEGM 55^Twas used for studying biodegradability of dehydroabietic acid (C₂₀H₂₈O₂, САS: 1740-19-8, abieta- 8,11,13-trien-18-oic acid, DAC) – a toxic tricyclic diterpenoid accumulated in wastewater of paper-and-pulp industry. A pronounced stability(MIC 390 mg/L) of Dietzia maris IEGM 55Т cells with respect to DAC was revealed. It was established that dietzia do not use DAC as an only source of carbon and energy, practically complete (97 %) destruction of 500 mg/L DAC being observed in 7 days under conditions of pre-cultivation of dietzia in the presence of n-hexadecane. The influence of DAC on the vital capacity and respiratory activity of dietzia was studied. The method of determination of antimicrobial activity was used to show that extracts of the prepared metabolites are not apparently toxic in comparison to that of the initial substrate. The data obtained expand the knowledge on the catalytic activity of actinobacteria and on their potential contribution to decontamination of natural ecosystems from ecotoxicants.

The article presents results of investigation and comparative analysis of process characteristics of commercially important dextran production from sucrose by using immobilized cells of bacteria Leuconostoc mesenteroides subsp. dextranicum B–5481 in forms of free and immobilized into poly(vinyl alcohol) cryogel. It was shown that dextran concentration was 1.2 times higher up to 1.2 times when immobilized cells were used in comparison with suspended cells under identical process conditions. The high process productivity was revealed (4.2 g/l/h) under batch fermentation conditions for immobilized cells in addition to their prolonged operation activity without any loss of metabolic activity for at least 5 working cycles. In comparison with analogues the productivity of developed biocatalyst was 5 times higher than that of Weissella confusa cells immobilized in calcium alginate gel, and 34-times higher as compared to Leuconostoc mesenteroides KIBGE HA1 cells entrapped into polyacrylamide gel. Samples of dextran produced by immobilized cells L. mesenteroides B -5481 had twice lower molecular weight as compared to the polymer synthesized by free cells. This characteristic expands the range of possible applications of the obtained polysaccharide without need in its additional hydrolysis.

The results of investigation and comparative analysis of biocatalytic process of pullulan production by a high cell density populations of Auerobasidium pullulans cells taken in suspended and immobilized into poly(vinyl alcohol) cryogel forms are performed in the work. The possible effective using of the immobilized biocatalyst was demonstrated and the characteristics of the process of pullulan production from different hydrolisates of renewable raw materials such as tubers of Jerusalem artichoke, aspen, Chlorella vulgaris biomass, potato pulp were determined. It was revealed that A. pullulans cells entrapped into poly(vinyl alcohol) cryogel can 1.5-times faster convert glucose to pullulan and accumulate the polysaccharide in cultural broth in 1.7-times higher concentration as compared to suspended cells. Immobilized cells appeared to retain a high functional metabolic action during at least 15 working cycles with minimum (not more than 10 %) loss of activity. The analysis of experimental data confirmed that use of cells immobilized into poly(vinyl alcohol) cryogel enables decrease in 1.5–3 times the duration of the working cycle in the same process while achieving comparable level of product yield.