G. Ya. Gerasimov

Mechanism of gas-phase degradation of polycyclic aromatic hydrocarbons by the action of ionizing radiation

The most comprehensive kinetic model for the gas-phase radiation-chemical degradation of polycyclic aromatic hydrocarbons is proposed on the basis of analysis of published data, which takes into account both the radical and ion-molecule mechanisms of the process. The model was verified by comparing the calculation results with the experimental data. It was shown that the efficiency of the process is lower in dry gas mixtures in which the ion-molecule mechanism plays the principal role in the degradation of aromatic molecules than in wet mixtures in which the radical mechanism dominates.

Gas-phase radiation-chemical formation of dioxins from chlorinated phenols

The gas-phase radiation-chemical formation of dioxins from chlorinated phenols in the electron-beam removal of toxic impurities from industrial gases is considered. A kinetic model of the process is proposed. Conditions under which the efficiency of removal of the above compounds from gases significantly decreases were determined with the use of this model. The results of a numerical simulation are compared with currently available experimental data.

Simulation of the Behavior of Dioxins under the Conditions of Electron-Beam Gas Cleaning of Sulfur and Nitrogen Oxides

The efficiency of the electron-beam treatment of gases for the removal of sulfur and nitrogen oxides was examined as applied to dioxins. The gas-phase and liquid-phase degradation of dioxins and the oxidation of condensed carbon to form dioxins were taken into account in a model for the behavior of dioxins under the action of ionizing radiation. It was found that the formation of dioxins can significantly decrease the removal efficiency. Under certain conditions, the initial concentration of dioxins can increase.

Modeling of the Transformation of Sulfur Compounds in Oxygen Gasification of Coal Dust

It is shown that, owing to the presence of a large amount of Ca and Fe in the mineral part of a fuel, it is possible to substantially reduce the sulfur content in the gaseous phase and, hence, improve ecological indexes of the process under the following conditions: the content of O2 is close to the stoichiometric value for fuel gasification, the temperature is ≈(1600–1800) K, and the pressure is ≈ 10 atm or higher.

Formation of Dioxins by Incineration of Chlorine–Containing Fuels

Based on the analysis of available kinetic data on high–temperature transformation of aromatic and chlorine–containing compounds, a kinetic model of the process is constructed, which offers a qualitative description of the dynamics of the dioxin–formation process and quantitative estimates. Numerical results are compared with experimental data.

Modeling of the pyrolysis process of coal particles

A mathematical model of pyrolysis of coal particles is developed that takes into account the heat transfer of a particle with the surrounding medium, the kinetics of release of volatile components, the secondary reactions of cracking, and the depositions of tar in its motion in the particle pores. Calculated results are compared to available experimental data.

Gas-phase radiation-chemical oxidation of naphthalene

A kinetic model for the gas-phase radiation-chemical oxidation of naphthalene was developed on the basis of published data. The principal routes of naphthalene conversion were studied with the use of the model. It was shown that the main product of naphthalene radiolysis under the electron-beam dry scrubbing (EBDS) conditions of the removal of NO and SO2 from industrial gases is nitronaphthalene. The results of numerical simulation are compared with the experimental data.

Radiation-Chemical Formation of Ozone in an Oxygen-Containing Gas Atmosphere

The process of ozone formation in an oxygen-containing gas atmosphere by the action of ionizing radiation was studied. A kinetic model of the process was constructed for the O2–N2 system. The effects of the main parameters of radiolysis on the O3 formation rate were analyzed. The atmospheric emission of ozone from industrial-scale power units that employ electron-beam flue gas cleaning of harmful impurities was evaluated from the standpoint of its conceivable favorable effect on the Earth ozone layer.

Ionizing-Radiation Ignition of a Hydrogen–Air Mixture

The behavior of a hydrogen–air mixture under the action of ionizing radiation was studied. A kinetic model for radiation-chemical processes in the H2–O2–N2 system was constructed, and the effects of the main parameters of radiolysis on shifting its flammability limits were analyzed. It was found that, under normal conditions (p = 0.1 MPa, T0 = 300 K), the ignition of the stoichiometric mixture began at a radiation intensity of about 0.1 kGy/s. The induction period of the chain H2 oxidation reaction shortened with increasing radiation dose rate and pressure.

Thermodynamic analysis of the process of formation of sulfur compounds in oxygen gasification of coal

A thermodynamic approach to the description of the behavior of the system fuel–oxidizer in oxygen gasification of coal is used to reveal the main mechanisms of the process of capture of sulfur by the mineral part of the coal and to determine the fundamental possibility of the process for coals from different coal fields.