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The natural gas usage as a vehicle fuel in the mining industry is one of the priority tasks of the state. The article pays special attention to the component composition of natural gas from the point of view of its thermal efficiency during combustion in the combustion chamber of a power plant on a heavy-duty vehicle in difficult quarry conditions. For this, domestic and foreign methods for determining the main indicator characterizing the knock resistance of fuel in the combustion process – the methane number – are considered. Improvement of technical and economic indicators will be carried out by changing the composition of the gas mixture based on methane to fit the design features of the gas power plant, the methane number will be the determining indicator. A theoretical analysis of the influence of the methane number on such engine parameters as the compression ratio and the maximum speed of the flame front propagation in the second phase of combustion in the engine cylinder, expressed through the angle of rotation of the crankshaft, is presented. Based on the results of theoretical and experimental studies, the dependences of the influence of the methane number on the efficiency of the working process of the engine and its external speed characteristic were obtained.

The collision-induced far infrared spectrum of CF4–He gas mixtures was measured at 213 K. It is shown that the observed enhancement of the absorption represents the translational spectrum induced by isotropic overlap forces. The band shape calculations are consistent with the assumption that the collision-induced dipole moment varies exponentially with intermolecular separation, and the parameters of the dipole moment function have been determined.

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The possibility of using finely dispersed aluminum oxide for catalytic purification of effluent gases to remove noxious substances formed in calcination of coal blank parts in fabrication of graphite electrodes was studied.In calcination of coal blank parts in manufacture of electrodes, large volumes of effluent gases are discharged into the atmosphere. The gases contain polycyclic aromatic hydrocarbons (PAHs) exhibiting carcinogenic and mutagenic properties and polluting the environment.The presently employed technique for purification of effluent gases from kilns with tar electric filters of the S-7.2 type is inefficient [1]: the extent of PAH removal does not exceed 85% [2] and amounts to 623 84% for tarry substances, including 51381% for benzo[a]pyrene [3].The aim of this study was to find conditions under which PAHs can be completely burnt directly in holders in kiln chambers (at places of their evolution from the material being calcined), filled with blank parts and a charge containing a catalyst, aluminum oxide. As is known, Al 2 O 3 exists in several polymorphic modifications differing in the structure and properties [4]. The most readily available for industrial use are low-temperature modifications of aluminum oxide, g-and c-Al 2 O 3 and mixtures of these. They are manufactured industrially on a large scale, and, therefore, their activity as catalysts for purification of gases to remove tarry substances was examined in this study. It is more difficult to obtain other modifications and, in particular, a-corundum in a finely dispersed state.It has been shown previously [537] that hydrocarbons decompose at the surface of aluminum oxide to give carbon. The carbonization occurs at a partly reduced surface of Al 2 O 3 , probably, by the mechanism of a carbide cycle [8310]. This is indicated by the fact that both a layered carbon deposit [6, 7] and thread-like tubular carbon [7] are formed on aluminum oxide. Tubular carbon is formed with a drop-like particle of metallic aluminum at the end (head) of a thread. It is known that the rate of carbonization and morphology of carbon formations depend on the relative rates of formation and decomposition of a carbide-like compound. In this case, carbon is formed on aluminum oxide by the scheme 1 C + 9 777 C n H m , where steps 1, 2, and 3 are sorption of a hydrocarbon C n H m on the surface of aluminum oxide, decomposition of the complex to give a carbide-like compound, and decomposition of this compound into aluminum and carbon with the subsequent reaction of aluminum with the hydrocarbon to give a carbide-like compound (carbide cycle).The carbonization hinders phase transitions of Al 2 O 3 and leads to an increase in their temperature [11, 12]. Under the action of oxygen-containing media on carbonized aluminum oxide, the deposited carbon burns-out, and Al 2 O 3 is regenerated. If carbon burnsout at temperatures equal to, or lower than, the carbonization temperature, then the specific surface area, pore structure, and phase composition of regenerated aluminum oxide re...