Flame propagation characteristics and surface functional groups changes of corn starch dust during the combustion process

Corn starch (CS) is one of the most common powders in industrial production and daily life, but its inherent risks of ignition and explosion cannot be disregarded. In this study, the flame propagation behaviors of CS at various concentrations were studied by a dust ignition experiment system. Meanwhile, the combustion process was analyzed in detail by differential scanning calorimetry tests, and the changes of key groups in molecules during the combustion process were monitored in real time by in-situ diffuse reflectance infrared Fourier transform spectroscopy tests. Based on this, the reaction process of CS combustion was analyzed. It was found that the dust concentration had a marked influence on the flame propagation characteristics. The oxidation process of CS underwent four stages in sequence: water evaporation stage, transition stage, rapid combustion stage, and coke carbonization stage. There were four key functional groups in the CS molecule: C-O-C, CH, CO, and -OH.