Experimental study on the influence of three typical surfactants on the explosion characteristics of coal dust clouds

Abstract

The extensive application of surfactants in wet dust removal technology may alter the combustion and explosion risk characteristics of coal dust. This is of great engineering significance for the safety prevention and control in the process industry. To assess the impact mechanism of surfactant treatment on the safety parameters of dust explosion, this study selected three typical surfactants (SDS, Triton™ X 100, and CTAB) and systematically investigated the evolution rules of the explosion hazards of coal dusts with different degrees of coalification (lignite, bituminous coal, anthracite).Using a 20-L explosion chamber, the explosion parameters (P_max, (dP/dt)_max) were measured. The thermodynamic behavior and functional group evolution were analyzed by integrating TG/DTG-DSC and FTIR techniques. The study revealed that the regulation of explosion intensity by surfactants is coal rank dependent. Specifically, SDS treatment significantly enhanced the explosion pressure of lignite (with a 13.0 % increase in P_max) while inhibiting the explosion reaction of anthracite. Triton™ X-100 generally reduced the explosion risk but exhibited coal-ank sensitivity (the inhibition efficiency of lignite was merely 18.7 % of that of anthracite).Mechanistic studies indicate that surfactants alter the reaction pathway by regulating the key active sites (hydroxyl/oxygen-containing functional groups) of coal-oxygen recombination. Hydroxyl groups play a dominant role in the explosion-enhancing effect of low-rank coal, while the explosion inhibition of high-rank coal is associated with the recombination of oxygen-containing groups. This research uncovers the dual-safety effects of surfactants in the dust-removal process and offers a theoretical foundation for the risk-graded prevention and control of wet dust-suppression systems in the process industry.