A software package consisting of the TETRAN-PRO and the COND-KINET-1 proprietary computer codes, as well as computational methods and models they are based on, is described. The TETRAN-PRO code calculates the composition and thermodynamic properties of a multicomponent reacting system under thermodynamic equilibrium conditions, including products of combustion or pyrolysis of organic and composite fuels. The difference of this code from similar ones is the use of the method of prevailing components, which is most effective as to convergence, computation time, and the range of parameters used. The code includes the necessary database of the original thermodynamic properties for 3000 individual substances. The TETRAN-PRO code’s capabilities are demonstrated by the results from calculation of mercury vapors’ conversion in the combustion products of Kuznetsk and Berezovo coals. The COND-KINET-1 calculates the parameters of a condensing aerosol formed during the volume condensation in a vapor-gas mixture f low. The process is described with a system of moment equations for the droplet size distribution function, which is closed by the equations of motion and energy. A comprehensive approach, thermodynamic and kinetic, has been formulated to the description of the volume condensation in multicomponent reacting systems based on the TETRAN-PRO and COND-KINET-1 codes. The approach’s capabilities are demonstrated by the example of numerically simulating the formation of environmentally dangerous submicron particles in burning coals according to the condensation mechanism. Data on the concentration and size distribution of the generated particles are obtained. The predicted data on the fractional composition of particles are compared with the experiment.

One of the priority scientific areas for many years at the Krzhizhanovsky Power Engineering Institute (ENIN) has been studying the processing of low-grade solid fuels with the production of valuable lighter hydrocarbons in demand in the energy and chemical industries. From 1970–1990 with the direct participation of the institute’s staff, a technology was developed and mastered on an industrial scale for the processing of oil shale using solid coolant. The article shows that ENIN created a serious scientific basis and developed methods for studying the thermal decomposition of low-grade fuels in their various modifications, which allows them to be used for experimental studies into the processing of a wide range of organic materials. Information is provided on the results of studies at the ENIN full-scale experimental stand on the creation of a new technology based on the pyrolysis of organic compounds (low-grade fuels) with the rationale for its use for solving the urgent task of class B and C waste disposal. The circuit diagram is described in detail and the experimental stand’s main components playing a key role in the technological process of environmentally friendly disposal of medical waste (MW) are described. Much attention is paid to the issue of quenching (high-speed cooling) of exhaust gases, which plays a major role in preventing the secondary formation of dioxins. Calculation of the quenching device in the ANSYS Fluent software environment is verified using experimental data. The results of the experiments showed that the measured concentration of dioxins and furanes in the exhaust gases obtained at the ENIN experimental stand during its operation on a typical model mixture of medical waste without the use of special gas purification agents amounted to 0.03 I-TEQ (I‑TEQ—dioxin equivalent) under normal conditions at a concentration of O 2 equal to 11%, which is lower than the European standard (0.1 I-TEQ).

A review of the work devoted to studying the service life of power equipment’s elements shows that important characteristics, such as silicon content, polydispersity, and particle shape of transported materials, are not taken into account in the formulas for calculating the abrasive wear of the hydrotransport pipelines of TPP’s ash- and slag-removal systems. There are separate experimental values of the coefficients of relative abrasiveness of ash and slag materials, which differ significantly. Abrasive wear leads to a decrease in the reliability of the hydraulic ash-removal system, forced equipment downtime, environmental degradation in places where slurry pipelines are depressurized, and lower economic efficiency of ash and slag transportation. The causes of increased abrasive wear are considered, which leads to a decrease in the service life of pipelines of ash- and slag-removal systems in thermal power plants. The main factors affecting the abrasive wear of pipelines are identified, and their impact is evaluated. It is shown that one of the key characteristics that affect the wear rate of slurry pipelines is the abrasiveness of the transported material, which, in turn, depends on the content of silicon oxides as well as on the shape and size of the ash particles. The results of calculating the specific abrasive wear of slurry pipelines for various speeds and mass concentration of pulp during its transportation from boilers in which three types of coal of various characteristics are used as fuel are presented. The results can be used in planning the timing of repair and maintenance work in order to increase the overhaul period of hydraulic ash-removal systems.

Heat and mass transfer processes and decomposition of organic compounds in a pyrolysis reactor are simulated using the ANSYS Fluent software package. Simulation of the pyrolysis of organic compounds, in contrast to simulation of their combustion, is dealt with only in a few studies. However, there are many engineering applications of this process, including thermal decomposition of various wastes where the use of pyrolysis, due to its specifics, seems to be very promising. Because of the wide variety of organic compounds, implementation of their processing in practice using the pyrolysis process depends heavily on the properties of a given feed and requires theoretical justification. A pyrolysis reactor equipped with a mixer is described, and the problem in the computer simulation of wetted polypropylene’s thermal decomposition is formulated. Polypropylene is a component of many medical products, such as catheters, transfusion systems, disposable syringes, etc. It has the highest decomposition heat among all components of medical waste and controls the maximum time of their decomposition. A description is given of a two-phase mathematical model consisting of the well-known mass, momentum, and energy conservation equations, mass transfer equation, and equation of state. The results from calculation of the propylene pyrolysis and the dynamics of thermal decomposition of a solid phase in a reactor are presented. The time of moisture evaporation and pyrolysis of a specimen at 600°С was determined. The hydrodynamic and heat transfer characteristics of the process enabling the performance of a thermal processing package and the requirements for the design of a test facility are considered. The results on the rate and time of polypropylene decomposition offer prospects for predicting the throughput capacity and loading frequency for the investigated reactor.

Upon analyzing the methods for processing epidemiologically hazardous medical waste (MW), it has been shown that the problem of safe disposal of MW with respect to the formation of polychlorinated dibenzo-para-dioxins and dibenzofurans (dioxins and furans) is acute and requires scientifically sound solutions. The typical morphological and elemental composition of the MW classes B and C and their thermal properties were determined, and the modern literature on the processes of thermal detoxification of dangerous MW was analyzed. It has been found that the process of pyrolysis is the most adaptive to various types of solid waste. Currently, pyrolysis attracts special attention due to its flexibility in treating various combinations of wastes only by changing the operating parameters of the process, such as temperature and heating rate. Pyrolysis is particularly important in connection with the growing amount of polymers in the waste of medical institutions, including those containing chlorine. In this case, the pyrolysis method presents the possibility of using a number of circuit solutions to prevent the formation of dioxins and furans. It has been shown that the use of the pyrolysis method ensures, along with full satisfaction of the requirements of sanitary and hygienic standards, the environmental safety of the MW detoxification process as compared to other high temperature methods (combustion and gasification). Next, possible directions of utilization of secondary resources received in the process under consideration were analyzed. In the proposed scheme of the installation for safe disposal of medical waste on the basis of the pyrolysis process, its products (excess gas, heat of the products of combustion, etc.) are expected to be used to generate electrical and thermal energy; semicoke as a solid residue of the process will be converted to activated carbon.

The complex analysis of the chemical composition and technological properties of oil shale from the Green River formation was carried out. The technical characteristics and granulometric composition of test samples and the element compositions of the mineral and organic matters of shale rocks were determined. The structure of organomineral aggregates formed upon the crushing of shale rocks was studied by electron microscopy. Based on the experimental data, a procedure was developed for the separation of kerogen from the oil shale by physicochemical processing.