Papers by Keyword: Oil Shale

Abstract: The development of the fuel and energy complex entails a direct increase in energy consumption and the development of fundamentally new types of resources. In the near future, it is predicted that the role of solid fuels, including low-grade ones, will increase in the country's fuel and energy balance, which is primarily due to their large reserves. Russia ranks third after the USA and Brazil in the world for this mineral and, according to the latest estimates, potential reserves of this raw material are in the order of 700,288.85 million t. The article is devoted to the analysis of the chemical composition of oil shale of the Leningrad field. The point microanalysis of oil shale was carried out on the scanning electron microscope TESCAN, and IR spectra of various functional groups that are part of the shale were obtained and analyzed. It has been revealed that the functional groups C-C, C=O, CH₂, CH₃, SH are typical for the organic component of the oil shale of the Leningrad field. Carbonates, silicates and hydroxides mainly represent the mineral part with impurities represented by phosphates, sulfides and sulfates.

Abstract: The article is devoted to the analysis of the influence of heat treatment of oil shale of the Leningrad field on the total surface area of nanopores and total porosity. Oil shale with particle size up to 0.125 mm in the form of powder and in the form of shale briquette was subjected to heat treatment. The change in the total porosity was studied in the temperature range (0÷1000) oC. The change in the total surface area of nanopores was studied by comparing the initial sample of oil shale with the oil shale ash obtained at 1000 oC. The data presented in this paper is indicative of a decrease in the oil shale nanopores total surface area under heat treatment, for example, for pore diameters (3÷4) nm the area decreases from 15.29 cm²/g to 2.563 cm²/g.

Abstract: The electrical treeing phenomenon is being actively studied in relation to polymer dielectrics like epoxy resin and polyethylene. In these materials treeing is the cause of degradation and failure of insulation parts. However, treeing is also found in other materials, where it can be used purposefully. Peculiar kind of treeing can be observed in solid fossil fuels. There are significant differences in the mechanism of treeing in solid fuels and organic dielectrics. These differences are specified by physical structure and chemical content of solid fuels, and also by thermal decomposition of organic matter under discharge influence. Treeing in solid fossil fuels leaves conductive tracks in rock. This allows using it in processing technologies, including in situ conversion.

Abstract: Extraction of shale gas and oil has significantly benefited the US economy. However, the applied technology of hydraulic fracturing is inefficient and ecologically unsafe. Electrophysical underground pyrolytic conversion of oil shale kerogen in energy stock can solve these problems. This processing method is feasible due to treeing in rock volume. Treeing has been widely studied in insulation as a negative factor. With regard to oil shale this phenomenon is examined insufficiently despite the fact that in this application area it has its distinctive features and is crucial for the initiation of rock heating and its further conversion. This article describes the shale’s dendrite morphology which is non-typical of conventional treeing in insulation. Features of the discharge structures’ formation are associated with a change of oil shale conductivity by discharge and with a high degree of rock heterogeneity.

Abstract: This article describes the thermogravimetric analysis (TGA) with TGA results obtained for the Russian Respublika Sakha Olenek, Kuznetsk Basin Dmitriyevka and Sergeyevka, and Chinese Jilin province Huadian oil shale deposits in air and argon medium. Industrial applicability of each shale deposit is estimated.

Abstract: The thermal behaviour of different oil shale samples (Estonia, Jordan, Israel, Morocco) were studied using a Setaram Setsys 1750 thermoanalyzers coupled to a Nicolet 380 FTIR Spectrometer. The experiments were carried out under non-isothermal heating conditions up to 1000 °C at different heating rates in an oxidizing atmosphere. A model-free kinetic analysis approach based on the differential isoconversional method of Friedman was used to calculate the kinetic parameters. The thermooxidative decomposition of oil shale samples proceeded in three steps. Firstly, thermooxidation of volatile organic compounds occurred – depending on the heating rate, up to 460 °C. Secondly, thermooxidation of heavier part of organic matter (kerogen) and fixed carbon as well as thermooxidation of pyrite proceeded up to 580 °C. Finally, carbonates contained in oil shale samples decomposed up to 870 °C. The combined TG-FTIR study of thermooxidative decomposition of samples made it possible to identify in addition to CO2 and H2O as major gases evolved a number of gaseous species like CO, SO2, COS, methane, ethylene, etc. formed and evolved at that. The value of activation energy E in the low-temperature oxidation region was for Estonian and Jordanian oil shale samples lower than that in the high-temperature region which was contrary for Israeli and Moroccan oil shale samples. Therefore, the results obtained indicated the complex multi-step character of the thermooxidative decomposition of the oil shale samples studied.

Abstract: The pyrolysis kinetics of Chinese oil shale and its kerogen was investigated using thermo gravimetric analysis (TGA) in this paper. Experiments were performed at four different heating rates of 10, 15, 20 and 25°C/min from ambient temperature to 560 °C at nitrogen flux with 60ml/min. The results demonstrated that the thermal decomposition of oil shale and its kerogen involved three degradation steps. Different thermo gravimetric data were analyzed by Friedman procedure. The values of apparent activation energy E of oil shale ranged from 160kJ/ mol to 240kJ/mol, but these of kerogen were in the range of 150kJ/mol to 240kJ/mol. It was found that the plot of lnA versus E became a linear line with a regression coefficient of 0.99.

Abstract: This study analyses the Fushun oil shale semi-coke samples prepared in 450°C, 550°C and 650°C by using STA449 TGA. The experiment studied their ignition points, concluded that with the ascent of the char-making-temperature the semi-coke’s ignition point is getting higher. The test used Coats-Redfern way to study the semi-coke’s activation energy. The result shows the semi-coke’s thermal dynamic model needs two different reaction orders in different temperature. In low temperature the reaction order is n=1; in high temperature it is n=3. When the temperature is low (n=1), the activation energy doesn’t influenced by the heating rate. In high temperature condition the activation energy is getting bigger with the ascent of the heating rate.

Abstract: Oil shale resources is a new energy has a huge potential for development, as the complement and alternative energy of the oil and gas, more and more people pay attention to it. China's oil shale resources are widely distributed and reserves are huge, but current mining methods are still primitive, mainly to direct exploitation, exploitation efficiency is low and ecological damage is serious, it will be replaced by in-situ mining methods in the future. This paper summarizes the research of oil shale in situ mining, aims at the problems of that the conduction of heat efficiency is low and the outlet channel is less which exist in the in-situ mining at the present, and put forward the concept of in-situ broken that is using some methods to make the oil shale change from huge to small block in the initial stage of the in-situmining, further in-situ heating, mining of oil shale，and put forward the method of in-situ noncontact wind breaking oil shale, this method using the crushing wind to break the oil shale, having high feasibility. This paper did in-depth research on the in-situ mining, and it can provide a reference for the development and utilization of oil shale resources.

Abstract: Proximate analysis, ultimate analysis and CO₂ of carbonate were determinated for the aboveground oil shale in Daqing exploratory area. The experiments of pyrolysis of Daqing oil shale were carried out in a fixed-bed reactor in order to study the influence of the pyrolysis temperature and the constant temperature time on oil shale pyrolysis characteristics. The results show that the effect of the pyrolysis is optimal under the conditions of 500°C and the constant temperature time for 20 min, with the yield of shale oil for 28.78% (the yield based on kerogen, similarly hereinafter). The mechanism of the oil shale pyrolysis was discussed. The pyrolysis reaction kinetics of oil shale was studied combining the experimental results of fixed-bed pyrolysis. The reaction activation energy is 28.92 kJ/mol during generating the shale oil process, while the reaction activation energy is 11.21 kJ/mol during generating char process. The yield curve of shale oil changing with the temperature was fitted to compare with the measured value with the constant temperature time for 20 min according to the pyrolysis kinetic parameters.