A. K. Golovko

The kinetics of oxidative desulfurization of diesel fraction with a hydrogen peroxide-formic acid mixture

The dependence of the oxidation rate of sulfur compounds on duration, oxidation temperature, and amount of the introducing oxidizer has been demonstrated with the straight-run diesel with a high initial sulfur content. The data for the oxidation rates of benzo- and dibenzothiophene homologues depending on the amount and the position of alkyl substituents in them during competing oxidation reactions of different diesel components have been obtained. The effective rate constants have been calculated for the oxidation reactions of the sulfur compounds during the oxidative desulfurization. The mechanism of the interaction of diesel sulfur compounds with the oxidant is proposed.

Thermal transformations of high-molecular-mass-components of heavy petroleum residues

Transformations of high-molecular-mass heteroatomic compounds (resins, asphaltenes) present in atmospheric distillation residue of crude oil from the Usa field (Republic of Komi) by thermal cracking at temperatures of 350–450°C in the presence of fly ash ferrospheres as initiator additives have been studied. The structural group parameters of resin and asphaltene molecules existing in the feedstock and the thermolysis products have been determined using elemental analysis, molecular mass, and proton NMR data.

Modeling of catagenetic transformation of saturated and alkylaromatic petroleum hydrocarbons

Thermolysis of crude oil at a temperature of 350°C for 1 h with and without aluminosilicates has been conducted in the isothermal regime mode. The composition of liquid and gaseous thermolysis products has been analyzed. The amount of resins and asphaltenes in the liquid products of thermal or thermocatalytic treatment decreases and that of oils increases as compared with the crude oil. The individual composition of saturated hydrocarbons (alkanes, steranes, terpanes) and alkylaromatic compounds (benzenes, naphthalenes, and phenanthrenes homologoues) has been studied. It has been shown that thermolysis increases the amount of thermodynamically more stable m- and p-isomers of alkyltoluenes, and the β-isomers of alkyl-naphthalenes and alkylphenanthrenes. Geochemical parameters for the composition of alkyl substituted benzenes, naphthalenes, and phenanthrenes have been calculated.

Cracking of heavy oils using catalytic additives based on coal fly ash ferrospheres

Finding new low-cost catalysts, especially ones that can be used in cracking, is a problem of great interest in the refining of heavy oils. The activity of redox catalysts based on coal fly ash ferrospheres is examined for the cracking of two types of heavy oils (paraffin and asphaltenic), and for paraffin oil residue under autoclave conditions. It is established that at 450°C and with 10 wt % of ferrospheres, the selectivity of the formation of liquid products can be as high as 95–96% for paraffin oil and 72% for asphaltenic oil. The content of light products and the gasoline fraction increases in liquid products in comparison to thermal cracking. The effect of ferrospheres is most pronounced in the cracking of paraffin oil: the light fraction in the oil cracking products grows by approximately 20% relative to those obtained after thermal cracking, reaching almost 67%; the gasoline fraction in the light products of oil residue cracking grow by 14 times. The phase composition and structural characteristics of ferrospheres change during cracking, carbon compounds with different combustion reactivity are deposited on their surfaces, and concentrated sulfur compounds from heavy oils are observed.

Thermolysis of Petroleum Asphaltenes and their Fractions

Asphaltenes isolated from Usa crude oil have been fractionated by fractional precipitation. The bulk asphaltenes and their fractions have been subjected to thermolysis. The sulfide, thianaphthene, and aromatic sulfur content in the molecules of virgin asphaltenes and their fractions has been calculated from elemental analysis and group composition data for the thermolysis products and the results of molecular mass (MM) determination. It has been shown that the amount of the alkylsulfide functional type of sulfur depends on the MM of asphaltenes and influences on the yield of thermolysis products.

Enhancement of catalytic activity for selective oligomerization of ethylene by microwave treatment

It has been found that the activity of a catalyst for selective oligomerization (trimerization) of ethylene based on a chromium salt and organoaluminum compounds (OACs) can be substantially enhanced by the microwave irradiation of organoaluminum compounds directly prior to mixing them with the chromium salt and a pyrrole ligand. The effects of irradiation conditions and the nature of the reagents used have been studied. The catalyst obtained according to an optimal procedure outperforms known analogs in activity.

Kinetics of the ethylene trimerization reaction on a homogeneous chromium-pyrrole catalyst

The results of studying the kinetics of the reaction of ethylene trimerization under the action of a homogeneous chromium-pyrrole catalyst have been presented. It has been shown that the reaction order with respect to ethylene decreases from 1.4 to a value close to 1 within 15 min after the start of the reaction, which is explained by the presence of two types of catalytic centers that catalyze the reactions of the first and second order with respect to ethylene. A model that includes the degradation of the second type of the catalyst during the reaction and inhibition of the activity of the first-type catalyst by the products has been proposed.

Thermocatalytic cracking of the natural bitumens of Kazakhstan

The heat treatment of the natural bitumens of Kazakhstan was carried out in the presence of a catalyst of power-generating ash microspheres and di-tert-butyl peroxide. Changes in the substantial and fractional compositions of cracking products depending on process conditions were established. Characteristic differences in the composition of liquid cracking products in the presence of the catalyst and the additive from the cracking products of the initial bitumen were found.

Combined cracking of brown coal and petroleum residue in the presence of initiating additives

The combined cracking of brown coal and petroleum residue was performed, and the composition of the products obtained was studied. The effects of initiating additives (fly ash ferrospheres from heat and power plants) and coal/residue ratios in the source material on the yields of distillate fractions in the course of cracking were examined.

Composition of naphthene hydrocarbons in crude oils from deposits of different ages

The composition of saturated cyclic hydrocarbons in crude oils from deposits of different ages located in various oil and gas basins has been studied. It has been found that the concentration of cyclanes in the oils decreases on passing from Paleozoic to Cenozoic deposits. For Cenozoic and Mesozoic oils, the concentration of cyclanes also decreases with the increasing occurrence depth of sediments within the same age. The group type composition of saturated cyclic hydrocarbons in oils from deposits of different ages is similar in character, where the concentration of cyclanes follows the order: monocyclanes > bicyclanes > tricyclanes > tetracyclanes > pentacyclanes.