Hydrogen inhibition method for preventing hydrogen explosion accident in wet dust removal systems

Abstract Wet dust removal systems pose hydrogen fire and explosion risks because accumulated aluminium dust can react with water to produce hydrogen gas. In this study, sodium silicate, which is an abundant and inexpensive chemical, was used to inhibit hydrogen production. If the reaction between aluminium dust and water in a wet dust removal system can be controlled, the risk of hydrogen explosion can be eliminated. Tests of the inhibition of hydrogen production were conducted using specialized equipment developed by our research team. The experimental results show that a protective film formed on the surfaces of the aluminium particles, which prevented them from reacting with water to produce hydrogen. When the concentration of the sodium silicate solution reached 2.5 g/L, essentially no hydrogen gas was produced. Scanning electron microscopy (SEM) was used to examine the surface morphology of the coatings on the aluminium particles. Energy-dispersive X-ray spectroscopy (EDS) revealed that Si was evenly distributed around the aluminium particles, indicating that the inhibitory film covered the aluminium particles. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) were used to analyse the chemical composition of the inhibitory film on the aluminium particles that were reacted with the 2.5 g/L sodium silicate solution. The application of a sodium silicate solution in wet aluminium dust removal systems resulted in the maximum reduction in cost and hydrogen explosion risk.