Suppression of different functional group modified powders on 9.5% CH4-air explosion and molecular simulation mechanism

Thiol and urea functionalized montmorillonite powders were successfully prepared by silane coupling agent treatments in this work. The pyrolysis characteristics, surface functional groups, and distribution of particle size of untreated montmorillonite powders (Mt), the hydroxyl functionalized montmorillonite (O-Mt), the urea functionalized montmorillonite (N-Mt), and the thiol functionalized montmorillonite (S-Mt), which was derived from the previous research, were respectively characterized by utilizing the thermogravimetric differential scanning calorimetry, Fourier transform infrared spectroscopy, as well as the laser particle analyzer. The suppression effect of the S-Mt, O-Mt, Mt, and N-Mt on a 9.5% CH4 explosion was tested in the duct system (5 L). The obtained results indicated that N-Mt and O-Mt exhibited a better explosion suppression effect than Mt and S-Mt at the same mass concentration. Additionally, the methane/air explosion suppression mechanism of these powders could be explained by molecular simulation results that indicated the negatively electrophilic potential regions exist on the surface of O-Mt and N-Mt. Moreover, NH4 NCO. and .OH radicals, which can interrupt explosive chain reactions, were easily generated by N-Mt and O-Mt.

Automated summary

Thiol and urea functionalized montmorillonite powders were successfully prepared in this study and characterized using various techniques. The results showed that N-Mt and O-Mt exhibited better explosion suppression effects at the same mass concentration compared to S-Mt and Mt. The mechanism of methane/air explosion suppression by these powders involves the generation of NH4 NCO. and .OH radicals, as well as the presence of negatively electrophilic potential regions on the surface of O-Mt and N-Mt.