Vol 56, No 8 (2016)

Current status of catalytic chemistry and technology for the manufacturing of high production volume chemicals, such as biofuel, higher olefins, and higher fatty alcohols, from the renewable feedstocks-inedible oils and fats is discussed. Analysis of achievements in the area of fundamental research and industrial application of inedible oils and fats is presented. The dynamics of growth in the production of biodiesel and biokerosene over recent years is shown. Various types of feedstock and deoxygenation catalysts are described. Modern concepts of the mechanisms of this process based on the results of kinetic and quantum–chemical studies on model acids and catalytic sites are discussed. New ways of selective preparation of olefins from vegetable oils and fats via decarbonylation of higher fatty acids over Cu and Ni catalysts are discussed. Industrial processes and catalysts for hydrogenation of higher fatty acids and esters into corresponding alcohols are considered. Published data on the mechanisms of these reactions are surveyed.

The physicochemical properties and composition of bitumens extracted from three different areas of the Pasar Wajo deposit, Indonesia have been comprehensively studied. It has been found that the bitumens are classified as asphalt in terms of density and oil content. Characteristic features of the composition of the bitumens are low concentrations of sulfur and trace elements and the lack of normal-chain hydrocarbons. On the basis of data on the composition and physicochemical properties of bitumen, possible processing routes, namely, the manufacturing of binders for road and construction purposes have been suggested.

Thermal transformations of petroleum components of paraffin-base heavy crude oil and oils (hydrocarbon concentrate), a mixture of oils and resins (maltenes), and a mixture of oils with asphaltenes isolated from the crude have been studied in order to assess the effect of resins and asphaltenes on the hydrocarbon conversion direction. Thermolysis of samples has been conducted at 450°C for 2 h in the isothermal mode. Data on the material balance of the process have been obtained, and the composition of the gaseous and liquid products of thermolysis has been determined. The gaseous products of thermolysis consist of hydrogen, carbon dioxide, and C₁–C₅ hydrocarbons. It has been shown that the thermolysis of all the samples is accompanied by the appearance of newly formed resins and asphaltenes. Analysis of the dynamics of changes in the hydrocarbon composition of the liquid thermolysis products has shown that the resins, rather than asphaltenes affect to a greater extent the direction of hydrocarbon cracking reactions.

Basic features of thermal degradation of mixtures of vacuum tower bottoms with pine sawdust have been studied by dynamic thermogravimetry. The kinetic parameters of the process have been determined using the integral model-free Ozawa–Flynn–Wall method. The enthalpies and ethropies of activation of the thermal degradation of the vacuum residue, the sawdust, and their mixtures have been calculated on the basis of the transition state theory. It has been shown that pine sawdust and its degradation products have an activity to enhance the kinetic parameters and the rate of thermal degradation of vacuum tower bottoms. It has been found that the E value of thermolysis of the heavy petroleum residue substantially decreases with an increase in the proportion of sawdust in the vacuuum resid to 225.0 kJ/mol for the mixture containing 18.0 wt % pine sawdust at a degree of conversion of the mixture of 0.8.

The hydroconversion of a mixture of rosin acids over a Pt-containing mesoporous aluminosilicate catalyst has been studied. It has been shown that in a temperature range of 300–350°C at pressures of 30–50 atm and a feedstock/catalyst weight ratio of 20/1, rosin acids undergo complete decarboxylation to form naphthenic and naphthene-aromatic hydrocarbons. Under optimum process conditions, the yield of diesel fuel hydrocarbons is more than 85%. The resulting fraction can be used as a fuel component.

The reaction features of the direct conversion of ethanol to butanol-1 and hexanol-1 in the presence of mono- and bimetallic active components based on Au and Cu supported on γ-Al₂O₃ have been studied. It has been found that under conditions providing the supercritical state of ethanol, the reaction rate and selectivity in the presence of the Au–Cu/Al₂O₃ catalyst abruptly increases. In addition, a synergistic effect is observed: the yield of desired products over the Au–Cu catalyst is 6 or 14 times that over the Au or Cu monometallic counterpart, respectively. Differences in the catalytic behavior of the Au–Cu, Au-, and Cu-based systems have been discussed taking into account their structural features and the reaction mechanism.

Oxidative desulfurization of a model mixture on the basis of vacuum gas oil and diesel fuel by hydrogen peroxide in the presence of formic acid has been studied. A technology of a two-phase system with a phase-transfer catalyst has been employed for the desulfurization. The optimum reaction time is 6 h and the hydrogen peroxide: sulfur molar ratio is 4: 1. As a result of successive triple oxidative desulfurization, 90% of total sulfur is removed from the model mixture.

The effect of the introduction of P₂O₅ into Ni–Mo/Al₂O₃ catalysts on their activity in the hydrotreating of vacuum gas oil has been studied. As the support, γ-Al₂O₃ prepared from aluminum hydroxide AlOOH powder of the TH-100 brand (Sasol) has been used. The catalytic properties of the catalysts obtained have been examined in the hydrotreating of vacuum gas oil in a continuous-flow unit under hydrogen pressure. The amounts of sulfur and polycyclic aromatic hydrocarbons, the hydrocarbon group composition, and the carbon residue of the feedstock and the hydrotreating product have been determined. The catalysts after testing have been studied using differential thermal analysis in combination with thermogravimetry (DTA–TGA); the influence of the amount of the modifier on the catalytic activity and coking of the catalysts has been shown.

The deposit formation process in water/oil emulsions based on waxy high-resin oils with different amounts of the aqueous phase has been studied. It has been shown that the deposition rate greatly increases with an increase in the relative amount of the aqueous phase. Relationships of the component composition of paraffin hydrocarbons and the structural group composition of asphaltenes in asphaltene–resin–wax deposits with the water content of the emulsions have been revealed.