Inhibition Effect of KHCO₃ and KH₂PO₄ on Ethylene Explosion

Abstract

The explosion risk of ethylene (C2H4) seriously hinders safe development of its production and processing. To reduce the harm caused by C2H4 explosion, an experimental study was conducted to assess the explosion inhibition characteristics of KHCO3 and KH2PO4 powders. The experiments were conducted based on the explosion overpressure and flame propagation of the 6.5% C2H4–air mixture in a 5 L semi-closed explosion duct. Both the physical and chemical inhibition characteristics of the inhibitors were mechanistically assessed. The results showed that the 6.5% C2H4 explosion pressure (P ex) decreases by increasing the concentration of KHCO3 or KH2PO4 powder. The inhibition effect of KHCO3 powder on the C2H4 system explosion pressure was better than that of the KH2PO4 powder under similar concentration conditions. Both powders significantly affected the flame propagation of the C2H4 explosion. Compared with KH2PO4 powder, KHCO3 powder had a better inhibition effect on the flame propagation speed, but its ability to reduce the flame luminance was less than KH2PO4 powder. Finally, the inhibition mechanism(s) of KHCO3 and KH2PO4 powders were revealed based on the powders’ thermal characteristics and gas-phase reaction.