Crude oil is an attractive fuel for energy production, since its use does not require additional processing costs. Existing technologies for burning liquid fuel do not always ensure the achievement of the modern ecological and energy performance when using highly viscous and substandard fuels. This relates to unstable ignition and combustion of such fuels in the combustion chamber, relatively fast coking of the burner surfaces, etc. The work deals with investigation of crude oil burning in a flow of superheated steam as a promising way to reduce nitrogen oxides (NOx) and increase the completeness of fuel combustion. The experiments were carried out using an original burner where liquid fuel is sprayed due to interaction with a high-velocity flow of superheated steam. This method of spraying allows the creation of a highly dispersed two-phase flow and prevents nozzle chocking and coking when using substandard fuel and waste. At the same time, steam gasification of products of fuel thermal decomposition allows the reduction of toxic emissions, increasing carbon burnout. The regimes of crude oil burning in a modernized burner that provide high completeness of fuel combustion (~44 MJ/kg) with a low content of nitrogen oxides and carbon monoxide in the combustion products have been determined. The amount of these toxic components corresponds to class 1 of EN 267. The results obtained confirm the effectiveness of the investigated method of fuel spraying by a superheated steam jet for environmentally friendly crude oil burning, including this process in the low-power burners (~15 kW). Such devices can be used for the cleaner elimination of liquid hydrocarbon waste with the receipt of thermal energy.

A series of experimental investigations is performed for determining the thermal and environmental characteristics of burning heavy fuel oil of the M-100 type sprayed by a jet of superheated steam in a laboratory prototype of a new burner. A scheme of liquid fuel burning preventing choking of narrow fuel channels of injectors is proposed; this scheme ensures effective burning of high-viscosity fuels and wastes. The process of stable burning of heavy fuel oil in a low-power (7 kW) burner with low concentrations of toxic emissions and high combustion efficiency is realized.

Four options for the power cycle using carbon dioxide as a working fluid during oxygen combustion of gaseous fuel are considered. In all the cases, heat is supplied within the zone of supercritical parameters of CO₂. The fundamental difference in options lies in the method of increasing the working fluid pressure. The heat is supplied to the cycle in the combustion chamber, and the cycle operation is accompanied by continuous updating of the working fluid, since part of CO₂ and all steam obtained during fuel combustion are removed from the cycle. It is shown that cycles with a single-stage pressure increase by a pump have the highest thermal efficiency, reaching 64.5 %. The effect of thermodynamic parameters on the energy characteristics of cycles has been estimated quantitatively.

In this work, a study of the efficiency of carbon dioxide energy cycles of different architecture is carried out. The relevance of these technical solutions in modern conditions is shown. Basic options of zero emission thermodynamic cycles using CO₂ as an cycle fluid are presented. It is shown that the efficiency of the analyzed CO₂-cycles with an initial temperature of 1000 °C will be 54-58%, depending on their configuration. It is presented that the efficiency can be increased up to 65% with an initial temperature increase up to 1500 °C.