Inhibition of sucrose dust deflagration by carbonate and kinetic study by thermal analysis

To prevent the explosion of sucrose dust, the ability of carbonate powders as a sucrose dust explosion inhibitor is systematically analyzed and compared. The explosion inhibition effect of carbonate powders on sucrose dust is investigated by means of minimum ignition energy (MIE) and 20 L sphere explosion experiments. The results indicate that as the amount of carbonate powder added increased, sucrose dust explosion can be completely inhibited. Compared with CaCO3, KHCO3, and NH4HCO3, the inhibitory ability of NaHCO3 is 25.00%, 40.00%, and 57.14% better for MIE and 25.00%, 33.33%, and 50% better for explosion properties. The kinetic model of thermal decomposition of sucrose dust before and after NaHCO3 intervention was comparatively analyzed and validated using Coats-Redfern (C–R) and Kissinger - Akahira - Sunose (KAS) methods. The kinetic modeling of the thermal decomposition of sucrose dust before and after the addition of NaHCO3 was found to follow the chemical reaction mechanism (F4 model). Further fitting analysis demonstrates that after adding NaHCO3 inhibitor, the apparent activation energy of sucrose dust is greatly increased, further confirming that carbonate powders can greatly inhibit sucrose dust explosion on thermodynamic terms. Finally, based on the characterization result, the inhibitory mechanisms of carbonates on sucrose dust explosion are proposed and two reasons explaining why NaHCO3 has better inhibitory ability than CaCO3, KHCO3, and NH4HCO3 are summarized. One is that the decomposition of NaHCO3 is a highly heat-absorbing process during which part of the heat produced by the combustion of sucrose dust is absorbed. The other is that NaHCO3 and its product have small particle sizes but large specific surface areas, consequently higher unit heat absorption capacity and better dispersivity. [Display omitted] •The values of Pmax and (dp/dt)max were maximized when the sucrose dust concentration was 750 g/m3.•The inhibitory effects of carbonate inhibitors on the explosion characteristics and ignition energy of sugar dust were systematically compared and analyzed, with NaHCO3 playing a particularly prominent role.•When the mass fraction of NaHCO3 added was 40 wt%, the critical state of complete inhibition of sucrose dust was reached; when the mass fraction of NaHCO3 added was 60 wt%, sucrose dust was completely inhibited.•The apparent activation energy of the mixed dust was significantly increased by the addition of NaHCO3 inhibitor.