A. L. Maksimov

Preparation of high-octane oxygenate fuel components from plant-derived polyols

The ketalization of polyols (glycerol, xylitol, xylose) in the presence of a number of heterogeneous acid catalysts has been studied. It has been shown that zeolite catalysts exhibit high activity in the formation of the acetone ketal of glucose in a flow system with the quantitative selectivity for the 1,2-product. The best catalyst is zeolite beta; in the presence of this zeolite and excess acetone, the yield is over 90% or, in the case of the structured reactor, even greater than 98% It has been shown that zeolite-based systems catalyze the formation of ketals of xylitol and xylose with a yield of up to 50% in the presence of excess acetone.

Platinum and palladium nanoparticles in modified mesoporous phenol—formaldehyde polymers as hydrogenation catalysts

Mesoporous polymeric supports modified with sulfo groups and PPI dendrimers have been prepared. Catalysts containing palladium and platinum nanoparticles have been synthesized on their basis. The resulting catalysts have been studied by transmission electron microscopy and X-ray photoelectron spectroscopy. It has been shown that the metal deposition procedure has an effect on the morphology of the resulting catalyst. Catalytic activity has been studied using the example of the hydrogenation of phenylacetylene and naphthalene at temperatures of 80 and 400°C, and pressures of 1.0 and 5.0 MPa, respectively.

Initiated conversion of ethanol to divinyl by the Lebedev reaction

A synergistic effect has been revealed upon hydrogen peroxide initiation of the catalytic ethanol-to-divinyl conversion process, proposed by S.V. Lebedev, on the (K2O)ZnO/γ-Al2O3 catalyst. The efficiency of the initiator has been examined, depending on the form of aluminum oxide, hydrogen peroxide concentration in the system, and the linear velocity of the feed stream. The behavior of the process characteristics has been analyzed and a kinetic model of the process has been proposed on this basis, enabling the selectivity of the initiated reaction to be controlled.

Oxidative functionalization of adamantanes (review)

The results of studies in the area of oxidative functionalization of hydrocarbons of the adamantane series over the last two decades have been summarized and oxidation, carbonylation, and carboxylation reactions involving oxidizing agents and catalysts of various types, possible reaction mechanisms, properties and promising directions of the use of the obtained products have been considered.

Heterogeneous catalytic conversion of glycerol with n -butyl alcohol

The etherification of glycerol with n-butyl alcohol at 140°C in the presence of sulfonated cation-exchange resins and zeolite catalysts in an autoclave reactor has been studied. It has been shown that styrene—divinylbenzene ion-exchange resins are effective catalysts for the production of glycerol n-butyl ethers: the glycerol conversion is about 98% with an n-butyl ether selectivity of about 88 mol % (140°C, 5 h, 5 wt % Amberlyst 36 catalyst, and 10 wt % glycerol in n-butanol). Zeolites Y and β in the H+ form exhibit comparable specific activity (glycerol conversion of no more than 25% under similar conditions) in combination with high selectivity for glycerol di-n-butyl ethers (up to 28%).

Hydrogenation processing of oil wastes in the presence of ultrafine catalysts

The results of investigations on the processing of carbonaceous waste, namely, oil sludge and oil vacuum distillation residue (vacuum residuum) by hydroconversion in the presence of molybdenum catalyst in situ generated in the hydrocarbon medium are presented. A scheme for separation of heavy residue of the hydrocarbon part of the sludge has been developed. The characteristics of the vacuum residue of the sludge hydrocarbon part and the vacuum residue of oil distillation have been compared. It has been shown that a high degree of conversion of the heavy hydrocarbon part of oil sludge can be reached using the complex scheme of separation followed by hydroconversion in the presence of the molybdenum catalyst generated in situ in the hydrocarbon medium.

Choice of a catalyst and technological scheme for synthesis of solketal

Results are presented obtained in tests of various homogeneous and heterogeneous catalysts in a synthesis of solketal (2,2-dimethyl-4-hydroxymethyl-1,3-dioxolane). It is shown that, all other conditions being the same, the highest catalytic activity is observed for sulfuric acid and beta zeolite. Data are presented on how the equilibrium constant of the reaction of glycerol ketalization depends on temperature. A technological scheme of the process for synthesis of solketal is suggested and its description is presented.

Synthesis of Ni–W aromatic hydrocarbon hydrogenation catalysts by the ex situ and in situ decomposition of a precursor based on a dendrimer network

A Ni–W precursor supported on a dendrimer-containing crosslinked polymer (42 wt % of a third-generation polypropylenimine dendrimer) has been first synthesized. The precursor has been subjected to the ex situ and in situ decomposition in a hydrocarbon feedstock to prepare an unsupported Ni–W sulfide catalyst. The activity of the resulting catalyst in the hydrogenation of aromatic hydrocarbons has been studied using the example of naphthalene. The process has been conducted in an autoclave-type reactor in a temperature range of 350–400°C at a hydrogen pressure of 5.0 MPa. It has been shown that the in situ synthesis of a Ni–W catalyst leads to the formation of particles exhibiting higher activity in the hydrogenation of naphthalene. The in situ synthesized Ni–W particles have been characterized by TEM and XPS.

Hydrofining of cycle oil using modified nickel-tungsten sulfide catalysts

The effect of palladium and ruthenium admixtures on the activity of an industrial NiW sulfide catalyst has been studied. It has been shown that Pd and Ru can increase the activity of the industrial catalyst in the hydrodesulfurization reaction of cycle oil by 8.0 and 2.8%, respectively. Under the experimental conditions, the hydrodearomatization of hydrocarbons composed of two or more rings results in the formation of monoaromatic hydrocarbons. The conversion of polyaromatic hydrocarbons in the temperature range of 260–300°C is 100%.

Modified mesoporous catalysts based on Al-HMS and Al-MCF for the oligomerization of α-olefins

High-performance decene-1 oligomerization catalysts based on mesoporous Al-HMS and Al-MCF aluminosilicates modified with an F-4SF sulfonated perfluorinated copolymer have been synthesized. Under batch conditions with a conversion of 90% and in a flow system with a conversion of 83%, these catalysts provide the formation of an oligomerization product with viscosity properties characteristic of poly-α-olefins, the precursors of poly-α-olefin oils.