Vol 58, No 1 (2018)

The genesis of higher alkyltoluenes with a normal alkyl chain (n-ATs) has been studied. The conditions for their formation from both individual C₁₈ (oleic and stearic) fatty acids and C₁₄ alcohol in the thermocatalytic mode and from Tasmanites planktonic algae during noncatalytic thermal treatment have been considered. The feasibility of the formation of n-ATs has been confirmed by determining their composition and structure.

Promoted Мo and W catalysts have been prepared in situ via thermal decomposition of precursors, oil-soluble salts Mo(CO)₆, W(CO)₆, С°C₁₆H₃₀O₄, and NiC₁₆H₃₀O₄. TiO₂, Al₂O₃, and ZrO(NO₃)₂ · 6H₂O have been used as the acidic additives. Also, Mo and W unsupported sulfide catalysts have been prepared in the presence of elemental sulfur as the sulfiding agent. The catalysts have been characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. The activity of the catalysts prepared in situ has been evaluated in the hydrogenation reaction of bicyclic aromatic hydrocarbons by the example of model mixtures of 10% solutions of naphthalenes (unsubstituted naphthalene, 1- and 2-methylnaphthalenes, and 1,5- and 2,3-dimethylnaphthalenes) in n-hexadecane. The effect of the precursor/acidic oxide ratio on the activity of the formed catalyst has been found. Hydrogenation of bicyclic aromatic hydrocarbons has been conducted at a hydrogen pressure of 2 and 5 MPa and a temperature of 380 and 400°C for 2 h. Hydrogenation of the unsubstituted aromatic ring has been preferable due to the absence of steric hindrances. The degree of conversion of n-hexadecane under the reaction conditions has been 1.5–7.5% depending on the reaction temperature. It has been found that the activity of the sulfided catalyst in the conversion of 1- and 2-methylnaphthalenes is inferior to the activity of the unsulfided analogue, while partial replacement of TiO₂ by Al₂O₃ results in a decrease in the conversion of the substrates as opposed to the unsulfided catalysts, in which the use of nanocrystalline Al₂O₃ promotes an increase in the conversion.

Novel catalysts based on neodymium–calcium cobaltate–nickelate complex oxides for the partial oxidation of methane to synthesis gas have been synthesized and studied using catalyst precursors with the general formula NdCaCo_1–xNi_xO_n (x = 0, 0.2, 0.4, 0.6, 0.8, 1) prepared by the solid state synthesis method. It has been shown that the synthesized samples form a series of solid solutions with a K₂NiF₄ structure at x ≤ 0.8 or a rhombically distorted K₂NiF₄ structure at x = 1. The products of conversion of the resulting precursors in a methane–oxygen mixture at high temperatures have shown high methane conversions and synthesis gas yields. The highest values of these parameters have been achieved in the presence of catalysts synthesized by the reduction of NdCaCo_0.4Ni_0.6O_n and NdCaNiO_n precursors. The complete replacement of cobalt with nickel has led to an increase in the synthesis gas yield; however, it has been found that the resulting catalyst is prone to carbonization. It has been determined that an optimum nickel to cobalt ratio in the catalyst composition provides the formation of a carbonization-resistant catalyst.

Phenol and butanolone catalyzed by different SO₃H-functionalized ionic liquids (ILs) for synthesis of raspberry ketone (RK) had been investigated. The influences of different ionic liquids, reaction time, reaction temperature, reactant ratio, the amount of ionic liquid were investigated. The yield of raspberry ketone was 82.5% under the optimum reaction condition. In addition, the ILs (3-sulfo)propyltriamine bisulfate ([TEA-PS][HSO₄]) can be recycled up to five consecutive times without loss of activity. This method had the advantages of mild conditions, high product yield, easy to separate from the product, as well as environmentally friendly procedure. At the same time, the possible reaction mechanism was discussed.

The kinetics of the pyrolysis of solid organic polymers by their heating with a gas or a metal melt have been studied. The design features of a small-sized pyrolysis unit for organic polymers have been determined. The pyrolysis process on this unit has been experimentally substantiated. The specifics of the processes of “conventional” pyrolysis in the gaseous heat carrier and the pyrolysis of organic polymers in a lead melt have been revealed. It has been shown that the resulting pyrolysis liquid can be used as a feedstock for the production of the expensive organic solvent limonene or synthetic oil similar in properties to domestic crude oil.

Polymethyl methacrylate (PMMA) is widely used as a substitute for glass, known as organic glass. During the processing and after use, there are amount of castoff. Based on the similar framework, PMMA could be useful feed stock to synthesis poly methacrylamide (PMAA) used for crude oil additive. In this work PMAA was prepared by aminolysis reaction of PMMA and aliphatic amines. The performance of PMAA on heavy oil was evaluated as pour point depressant as well as paraffin inhibiter. The highest pour point reduction depression was achieved as 12.1°С with the dosage of 600 ppm PMAA 1. Differential scanning calorimetry and paraffin crystal morphology studies were conducted to elucidate the mechanism of pour point reduction.

In this study, a thermo-responsive temporary plugging agent was developed with the property of sol-gel-sol transition behavior at different temperatures. At low temperature, the material is in sol state, while increasing temperature led to a stable gel formation, but the gel can transform to sol again upon further heating. This unique behavior was characterized by a series of SEM, FT-IR, XRD, rheology and viscoelasticity measurements. All scientific results showed non-covalent interactions between the components, which play an important role for the supramolecular gel formation. These findings provide this system can be applied as temporary plugging agent by the idea of temperature-induced smart material with the specialty of cross-linker and gel-breaker free. Physical simulation experiment results showed that the material is good mobility liquid at room temperature. After injecting to formation, the fluid gradually transformed to hard gel around 90°C with sufficient strength to block cracks. Upon further heating by formation, the hard gel would collapse to sol around 110°C without adding additional gel breakers, leading to flowback sufficiently and low damage to fracture. This novel temporary plugging agent also has potential use in diverting fracturing, network fracturing, drilling, well completion, well clean etc.