Study on spontaneous combustion risk of cotton using a micro-calorimeter technique

Spontaneous combustion of cotton is one of the major challenges during cotton storage. To investigate the thermal behavior of cotton and calculate its self-heating oxidation temperature (SHOT), which relates to the ambient temperate, a C80 micro-calorimeter connected with a high pressure atmosphere control panel was employed in this study. Three kinds of cotton samples were heated from 30 °C to 300 °C at four different heating rates. Based on the Semenov model and Frank-Kamenetskii theory, the thermodynamics and kinetics parameters of the oxidation of cotton in air were calculated. By comparison, it can be concluded that higher heating rate results in larger reaction heat and lower SHOT, and the more rapid is the heating rate, the higher are the onset and peak temperatures. Moreover, the two kinds of seed cotton show lower SHOT and larger reaction heat than the seedless cotton, which indicates that the storage of seed cotton needs to be paid more attention.