The technological circuit of this process is shown in a diagram in Figure 1. An electrical arc at atmospheric pressure usually appears as a constricted area of electrical and mechanical forces, which causes the plasma fluid to move away from the arc column. Plasma-chemical reactions occur in the reactive zone of an arc in the presence of a controlled amount of plasma-forming gas. The final product, consisting of a vitrified glass-like substance, is collected at the bottom of the reactor and is used as a raw material for a wide range of applications. The higher the temperatures reached by the arc, the more efficient the conversion of organic waste into light organics and primary elements [7; 8; 12; 13]. When plasma activating energy is applied, it is possible to increase the rate of chemical reactions by hundreds of times and achieve stable, high average temperatures of 1800-2500 \({}^{\circ}\)C inside the PChR. However, developing new design equipment generating a plasma arc for the treatment of hazardous waste or waste with high melting temperatures (up to 1400 \({}^{\circ}\)C) is impossible without knowledge and understanding of the features of high-temperature processes occurring in the gas discharge chamber of the PT and the PChR. The gases used as heat carriers differ significantly in their energy characteristics. Therefore, when selecting the forming plasma gas, it is necessary to consider the possibility of obtaining high enthalpy values, using this gas as a chemical reagent, and the inertness of the target products. In plasma-chemical reactors for material processing, a DC electric arc operating in an argon (Ar) atmosphere is typically used [11]. However, it is well known that, from an economic point of view, it is more beneficial to use high-enthalpy gases such as nitrogen, air, or hydrogen [10,11,14]. Plasma torches with DC electric arcs operating in an air or nitrogen atmosphere have been extensively studied [15,16,17]. However, the characteristics of the free-burning arc in the air or the nitrogen ambient, which are applicable to plasma-chemical reactors, have not been sufficiently studied. Therefore, studying arc plasma behavior in an air atmosphere is beneficial. The efficiency, heat transfer characteristics, and interaction between a plasma jet and material in a PChR for waste destruction have been studied in many studies--for example [2,9,11]. However, the electric arc characteristics and the energy balance at the plasma torch anode were mainly investigated while working with an argon arc. A particular interest also appeared in the energy exchange between the plasma arc and the surface; the arc efficiency is higher when a plasma jet interacts with a flat surface. It is also well known that high-temperature argon gas has relatively low enthalpy and is a poor conductor of heat and electricity. Therefore, the use of a high-enthalpy molecular gas, such as air or nitrogen, for material processing using plasma technology is more advantageous [18,19]. In many papers, the authors solving fundamental energy production problems, environmental protection, public health, etc. have appropriately selected a plasma source. However, the  
Figure 1: The diagram of plasma-chemical waste decomposition. application of plasma sources requires very complicated, expensive, and energy-receptive fundamental and applied investigations, which are necessary to create new and very effective PT. Sometimes, when plasma technology is investigated as a waste treatment tool, it is not easy to apply similarity theory or numerical simulation laws. Modern waste recycling and disposal methods are based on high-technology processes of their gasification with the production of synthesis gas [14; 20; 21] or two-stage combustion using steam, gas, combined-cycle turbines, or gas engines to generate electricity [18; 21; 22; 23; 24]. This second high-temperature stage guarantees the complete neutralization of processed products from the formation of dioxins and furans.