Vol 52, No 2 (2018)

The composition and properties of coal from the Bodonskoe deposit were studied. It was shown that this is low-sulfur (S^d = 0.3–1.0%) and medium-ash grade 1B brown coal with a high yield of volatile substances (V^daf = 56.1–60.9%). The humic acid content varies from 32.3 to 50.8%. The heat of combustion of coal is Q_s^daf= 26.0–27.4 MJ/kg. The concentrations of toxic elements in the coal samples are at a background level.

The effect of temperature on the torrefaction (mild pyrolysis) of peat was studied. The process was carried out under anaerobic conditions at atmospheric pressure and a temperature of 230–300°C. It was established that an increase in the temperature from 230 to 270°C leads to a certain decrease in the yield of biocoal and an increase in the gas formation. However, in this case, the fraction of carbon in the material increases by 10%. As a result, the calorific value of solid fuel increases to 25–26 MJ/kg. The process is characterized by a high carbon efficiency (about 90%)

The results of an analysis of the combustion behavior of the drops of organic coal–water fuels (OCWFs) prepared based on the flotation products (cakes) of the enrichment the coal of five grades (longflame, gas, coking, low-caking, and lean coals) and two petroleum products (petroleum residue and spent turbine oil) are presented. The experiments were performed under the conditions of the stationary fastening of an OCWF drop on the junction of a quick-response thermocouple in a flow of heated (from 500 to 1000°C) air. The following three combustion regimes were revealed for all of the test OCWF compositions: stepwise regime with slow heating (smoldering), intense gas generation regime with the boiling of liquid fuel components (boiling), and regime with a distinct tear-off zone of gas flow (torch). It was shown that the occurrence of the above combustion behaviors substantially depends on the characteristics of the OCWF components: the ash content and the yield of volatile substances of coal cakes and the boiling points and the ignition and combustion temperatures of the petroleum products used. Based on the results of the experiments, the ranges of air temperature changes characteristic of each of the three combustion regimes of fuel suspensions were established.

The review surveys the structure and properties of plant biomass and the processes of its thermal conversion into biocoal (pyrolysis, torrefaction, and hydrothermal carbonization). Attention is focused on the hydrothermal carbonization: the mechanism of reaction, the conversion of the individual components of biomass and the material as a whole, the properties of the resulting biocoal, and current trends in the application of this process are described (the use as fuel and in the production of adsorbents, catalysts, etc.).

The effect of the conditions of bituminous sand hydrogenation on the yields and properties of the resulting liquid hydrocarbons was studied. It was found that, on the hydrogenation of bituminous sand, hydrocarbon products of higher quality can be obtained with a higher yield, as compared with the products of pyrolysis. The conditions affording a maximum yield of synthetic oil or an increased yield of light hydrocarbons were determined.

The problem of waste processing remains of considerable current interest. Energy processing can become a method for its solution. For this purpose, the addition of higher grade fuel is frequently required in order to stabilize the process of thermal conversion. In this work, the effect of control parameters on the efficiency of the co-gasification of biomass (wood) and waste polymers in a dense layer was investigated. For this purpose, a mathematical model, which included blocks for describing drying, pyrolysis, and gasification processes for each particular component of a fuel mixture, was developed. The results of the calculation were compared with published data.

In this work, the chemical analysis of the initial and activated shale from the Kendyrlyk deposit of Kazakhstan is described. The activated shale was obtained in the high-temperature processes of carbonization and activation in the atmospheres of argon and water vapor, respectively. The electrophysical characteristics of the test shale were determined for first time by measuring the electrocapacity of samples in a temperature range of 293–483 K. The temperature dependences of the specific heat of shale were obtained by dynamic calorimetry. Based on the experimental data, equations for the temperature dependence of the heat capacity of shale were derived; these equations can be subsequently used for determining the thermal conductivity and thermal diffusivity of shale.