Research on flame propagation and explosion overpressure of oil shale dust explosion suppression by NaHCO3

The overpressure and flame propagation of oil shale dust explosions suppression by sodium bicarbonate (NaHCO3) are studied in a 20-L square closed vessel and Hartmann experimental device. oil shale dust was mixed with sodium bicarbonate (NaHCO3) with concentrations of 0%–70%. The results show that by increasing the mass percentage of sodium bicarbonate (NaHCO3), the flame propagation height, flame propagation speed and explosion pressure can be effectively reduced. The inhibition mechanism of sodium bicarbonate (NaHCO3) is proposed: on the one hand, the efficient decomposition of sodium bicarbonate (NaHCO3) in the flame can absorb the heat released during the combustion process, thereby cooling the flame, and the generated sodium carbonate can be adsorbed on the surface of the oil shale. Prevent the reaction from continuing; on the other hand, in a gas-phase explosion, free radicals such as sodium and gas-phase intermediate products such as sodium oxide (Na2O) react uniformly with free radicals and reactant oxygen (O2). Sodium-containing species act as oxygen species scavengers, and the chain reaction of oil shale explosion is interrupted. © 2021 Elsevier Ltd