Vol 52, No 1 (2016)

Catalytic hydroliquefaction of sapropels differing in organic matter and heteroatom contents in the presence of Fe₂O₃—Al₂O₃—SiO₂, (Co/Mo)Al₂O₃, and (Fe/Ni)Al₂O₃catalysts is studied. The process conditions [(Co/Mo)Al₂O₃catalyst, 450°C, reaction time 1 h, and partial H₂pressure 6 MPa] that maximize the yield of liquid products (53%) and convert the most sapropel organic matter (74%) are determined. It is shown that liquid products of sapropel organic matter degradation contain essentially C₈--C₂₉saturated hydrocarbons and aromatic and naphthenic and oxygen- and nitrogenbearing compounds in much smaller quantities. A scheme is proposed for catalytic hydroliquefaction of sapropel organic matter.

The Fischer-Tropsch synthesis was carried out over cobalt catalysts using gas from oil shale as a model. A broad hydrocarbon fraction can be obtained over cobalt catalysts using model mixtures (CO + CO₂+ H₂+ N₂) from Leningrad and Kashpir oil shale products. A study was carried out on the effect of the synthesis gas composition, support and promoter type, temperature, pressure, and volumetric stock feed rate on catalyst efficiency, carbon monoxide conversion, as well as the selectivity and yield of the liquid products. Liquid hydrocarbon selectivity up to 88.7% was achieved with low methane selectivity (3.3%). The hydrocarbons obtained show chain growth probability up to 0.87.

Inhibition of formation of methane hydrate with cubic structure CS-I and methane-propane (95.66 CH₄ + 4.34 C₃H₈ mole %) hydrate with cubic structure CS-II by isothermal method and method of cooling at the constant rate of 2°C/h, using 0.5% of a kinetic inhibitor (KIH) + 20.8% of the thermodynamic inhibitor (TIH) monoethylene glycol (MEG) is studied. It is shown that the synergic effect of increase in inhibiting capacity of a polymeric kinetic inhibitor (KIH) in the presence of 20.8% of MEG (TIH) is observed in the case of both methane hydrate and methane-propane hydrate inhibition. The synergy manifests itself in the form of increase in supercooling degree by 2.5-3°C that is attained in the KIH + TIH system before the initiation of hydrate formation as compared to a system that contains no TIH (MEG). The induction time is shown to depend on the degree of supercooling in the system while inhibiting CS-1 and CS-II hydrates with 0.5% KIH + 20.8% MEG. The obtained data indicate that KIH + MEG antihydrate reagents can be used to inhibit formation of technogenous gas hydrates at < 0C temperatures.

Ni-Mo catalyst precursors were prepared by the precipitation method. Ni-Mo bulk hydrodesulfurization catalysts were obtained from these precursors after proper drying, molding, and calcination. The effect of polyethylene glycol (PEG) with different molecular weights and in various dosages on the structure and catalytic properties of these catalysts was investigated by applying X-ray diffraction, low-temperature BET N₂ adsorption analysis, and scanning electron microscopic methods. It is shown that the structure, surface properties, and activity of the catalysts can be improved by adding PEG. The pore volume, specific surface area, and pore size of the catalysts increase gradually with increasing PEG dosage, and the dispersion of the active ingredient increases initially and then decreases.

The chemical composition of I-20A and I-40A industrial oils produced by various companies is studied by chromatomass spectrometry. These oils are found to have more than 20 nitrogen-bearing organic compounds, including ones that are hazardous to human health. It is shown that the composition of organic nitro-compounds of various batches of oils differs markedly. Steps for protecting the environment and health of workers from the identified compounds are proposed.

Controlled mud-cap (CMD) drilling is an advanced deepwater drilling technology. When the surface pump is shut down, the CMD system causes unsteady flow that may create control problems. A new mathematical model has been developed to simulate unsteady flow in CMD systems. The model predicts the transient flow, the equilibrium time, and the change in bottomhole pressure during the unsteady flow. The simulation results show that the flow parameters change rapidly during the first 10 min and that unsteady flow leads to fluctuations in bottomhole pressure. In combination with measured data, the transient flow behavior computed by the model can be used for early detection of well kick after shutdown of the mud pump.

A study has been made of 13 industrial fractionating towers having a variety of plate contact devices (S-valve, straight-through valve, rectangular-cap, and Glitch valve devices) and 11 industrial fractionating towers having a variety of cross-flow packing contact devices. It is demonstrated that the efficiency of contact devices of various designs is less in the stripping sections of the fractionating towers than in the concentrating sections. Analysis of the mechanisms of diffusion of fractionated components in vapor and liquid phases in contact devices shows that the diffusion coefficient in the vapor phase decreases from the top to the bottom of the tower as the concentration of high-boiling components increases. This reduces mass transfer from one phase to another in the contact device in the stripping section of the tower and, as a result, reduces the efficiency of the contact device in this section of the tower. It is shown that elevation of pressure in the tower and increased temperature gradient across the tower height cause further decline of the contact device efficiency in the stripping section of the tower.

A study was carried out on gasoline dearomatization in the presence of zeolites and subsequent ractionation of the alkylate to give dearomatized gasoline and an aromatic hydrocarbon concentrate. Catalyst acid sites were shown to play a part in the alkylation reactions. In the case of a feedstock with 1:1 aromatic hydrocarbon:styrene weight ratio, the aromatic hydrocarbon content in the gasoline was reduced from 22.58 to 6.51% upon complete styrene conversion. As a result, the gasoline component was environmentally friendly and phenylarylethane products suitable for use as dielectric liquids were obtained.

The possibility of reducing sulfur content of Astrakhan gas condensate in residual fuel oil by oxidative desulfurization using ozonized air is examined. The optimal conditions for oxidizing with ozone and for thermal decomposition of oxidized sulfur compounds are determined. The sulfur content in residual fuel oil can be reduced from 2.86 to 0.48 wt. %, whereupon hydrogen sulfide is removed completely from the residual fuel oil and the combustion heat increases.

It has been proven on the example of individual hydrocarbons that IR spectrometry can be used to analyze properties of base oils. A proximate viscosity, viscosity index, and pour point determination method was developed based on quantitative IR spectrometry using the areas of two characteristic peaks and regression analysis for API-classified group 3 and 4 oils. This method can be used for quality control and real-time study of base oils.

The effect of reaction temperature, reaction time, initial chemical oxygen demand (COD), excess O₂ (EO), and catalyst concentration on the efficiency of catalytic wet air oxidation (CWAO) treatment of refinery wastewaters consisting of various oily wastes, water, heavy metals, toxic compounds, etc. was studied. In general, COD decreases substantially with temperature, EO, and oxidation time. Addition of homogeneous Co²⁺-based catalysts reduces COD by as much as 98.7%.

In order to analyze the behavior of a polymer underground in the early stage of flooding, we propose a new method based on power-law steady flow of a fluid, taking into account threshold pressure. We use data from an injection well and geological parameters to calculate the flow behavior index, the average effective viscosity within the polymer-swept portion, the resistance factor, and other important parameters. The reliability of the method is confirmed by comparing the results with data obtained during well development with the results of the ECLIPSE hydrodynamic simulation. The new method lets us track the change in polymer performance over time, and can be recommended for use in drafting recommendations for field development in subsequent stages.