Synergistic effects in dust explosion characteristics of coal and biomass mixtures

The explosion of coal powder and biomass mixed dust poses a potential threat to the application of biomass energy. To study the explosion mechanism of mixed dust, this paper systematically investigates the changes in explosion flame characteristics and explosion parameters by varying the mixing ratio of the two types of dust under fixed dust concentration conditions. Experiments measured key parameters such as flame propagation velocity, flame temperature, and maximum explosion pressure under various mixing ratios. Combined with X-ray Photoelectron Spectroscopy(XPS) and Thermogravimetry–Mass Spectrometry(TG-MS) techniques, the composition and pyrolysis characteristics of the raw materials were analyzed to gain a deeper understanding of the explosion reaction mechanism. The results indicate that coal-biomass mixed dust exhibits significant synergistic effects during the explosion. As the biomass blending ratio changes, the explosion intensity and flame characteristics exhibit obvious nonlinear responses. Specifically, the explosion pressure and flame temperature first increase and then decrease with increasing biomass ratio, indicating the existence of a critical most explosive mixing ratio. Furthermore, XPS analysis of the post-explosion products revealed significant migration and functional group restructuring of elements such as carbon, hydrogen, and oxygen. This study provides the theoretical basis for understanding the explosion behavior and intrinsic safety control of coal-biomass mixed dust systems.