The object of the study is coal sludge and coal fines of the Shubarkol deposit and the Kuznetsk coal basin (Republic of Kazakhstan) for the production of coal-water fuel, which allows replacing liquid and gaseous expensive products. The resulting fuel (after treatment of coal seams and burial) from industrial waste should not harm the environment, which requires certain economic investments. For crushing coal and coal sludge in the crushing and grinding unit, an electrohydroimpulse device for fine grinding of materials was used, consisting of a control unit with a protection system, a pulse capacitor and a high-voltage generator (capacitor bank capacity 0.75 µF, pulse discharge voltage 15–30 kV, length of the interelectrode distance 7–10 mm). After grinding, fine coal particles rise to the surface of the water, and impurities settle at the bottom of the device, which allows enriching the product (flotation). Surface structures and coal fraction sizes were obtained using a Tescan Mira 3 scanning electron microscope. The main characteristics of coal-water fuel during vortex combustion were: the diameter of the fraction 0–250 microns – 63–74 %, process water – 36–24 %, special additive – 1–2 %. Coal-water fuel is similar to liquid fuel, and when transferring heat-generating plants to combustion of suspension, no significant changes in the design of boilers (units) are required. This makes it easy to mechanize and automate the processes of receiving, feeding and burning fuel, and the vortex combustion technology at a temperature of 950–1,050 °C guarantees fuel efficiency of more than 97 %. The given optimal parameters of electrohydroimpulse technology when introduced into production will allow not only grinding, but also enriching the coal product

This article proposes a method for grinding coal based on the use of the energy of a pulsed shock wave resulting from a spark electric discharge in a liquid. The main purpose of the scientific work is the development of an electric pulse device for producing coal powder, the main component of coal-water fuel. The diameter of the initial coal fraction averaged 3 mm, and the size of the resulting product was 250 μm. To achieve this goal, the dependence of the length of a metal rod electrode (positive electrode) on the length and diameter of its insulation is investigated. Various variants of the shape of the base (bottom) of the device acting as a negative electrode are considered, and an effective variant based on the results of coal grinding is proposed. An experimental electric pulse installation is described, the degree of coal grinding is determined depending on the geometric parameters. The optimal characteristics of the obtained coal powder have been established.

This study presents the development of a combined heating system for a bioreactor designed to improve the efficiency of organic waste biodegradation. The proposed system maintains the required operating temperature within a specified range without relying on external energy sources, thereby enhancing the sustainability and energy efficiency of the bioconversion process. A bioreactor heating system based on a “water jacket” that is heated by the combustion of coal–water fuel has been developed. The “water jacket” is a system of two 15 mm diameter tubes located along a cylindrical axis inside the bioreactor. Heated liquid flows through the tubes, accelerating biomass fermentation processes. A technology for preparing and burning coal–water fuel using a radial circulation injection device is offered. Calculations are performed to determine the optimal temperature regime for the combustion process. Optimal conditions for electric pulse coal grinding (28 kV, 600 discharges) were established, the required particle size distribution of 50–250 µm was achieved, and the ignition temperature of the coal–water mixture (650 °C) was determined. The findings may contribute to improved waste management technologies and environmental sustainability by reducing carbon emissions and waste generation.

This article considers several aspects of creating a combined bioreactor heating system without the use of external power grid power sources. It's known to intensify anaerobic digestion of organic waste, the bioreactor temperature is maintained within a specified range. A bioreactor heating system based on a "water jacket" , that heated by combustion of coal-water fuel has been developed. A technology for preparing and burning coal-water fuel using a radial circulation injection device is offered. Calculations are performed to determine the optimal temperature regime for the combustion process. The results obtained can contribute to the optimization of waste management technologies and ensure environmental sustainability by reducing carbon dioxide emissions and waste accumulation.