Suppression characteristics and mechanism of acetylene explosion by carbonate

Acetylene, as a fundamental raw material for industrial processing and the synthesis of organic products, is highly prone to explosion accidents when exposed to open flames. To investigate the inhibitory effects of carbonates on the explosion characteristics of acetylene, sodium carbonate and sodium bicarbonate powders were selected as explosion inhibitors. The 20 L spherical explosion device and the 5 L dust explosion flame propagation testing device were employed respectively to study the inhibitory effects of sodium carbonate and sodium bicarbonate powders on the explosion overpressure and flame propagation characteristics of acetylene. Combined with the results of Chemkin numerical simulations, the explosion suppression mechanisms of these two powders on acetylene explosions were elucidated. The experimental results show that when the concentrations of sodium carbonate and sodium bicarbonate are both 1500 g/m³, the explosion pressure of acetylene is reduced by 34.88% and 32.56% respectively, the explosion pressure rise rate is reduced by 51.35% and 54.9% respectively, and the continuity of the acetylene explosion flame structure is significantly decreased. The time for the flame to reach the top of the pipeline is extended by 120% and 130% respectively, and the average propagation speed is reduced by 54.54% and 56.52% respectively. The inhibitory effects of both powders are remarkable.The numerical simulation results indicate that as pyrolytic endothermic powders, sodium carbonate and sodium bicarbonate can effectively reduce the temperature of the reaction system. Meanwhile, the generated NaOH can combine with the high - activity free radicals in the reaction system to form stable products, thus achieving the explosion suppression effect. However, due to the difference in the concentration of NaOH generated by the pyrolysis of the two powders, the inhibitory effect of sodium bicarbonate is ultimately better than that of sodium carbonate.The research results are of great significance for a deeper understanding of the essence of acetylene explosions. They can contribute to the optimization of acetylene explosion suppression technology and further ensure the safe and efficient industrial production in China.