Improvement of a Combined Heating System for a Bioreactor Designed for Biogas Production Using Coal–Water Fuel

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.