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

Abstract

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.