Particle Size Influence on the Transport Classification Labels and Other Flammability Characteristics of Powders

“The same conclusion for biomasses was obtained: It is easy for the biomasses to start a self-heating process, but it does not usually ucceed, due to their composition [48].”

“To determine the beginning of the process, different methods have been developed, most of them based on thermal analysis techniques, as thermogravimetry and differential scanning calorimetry [9,10], as well as experimental techniques based on thermal decomposition [11], emission of flammable volatiles [12], critical s…”

“Particle size is an essential parameter for every ignition process, either when considering dust explosions [25] or when the product is dispersed in the air shaping a cloud before the possible ignition of the cloud.”

“Many authors have used thermogravimetry (TGA) and differential scanning calorimetry (DSC) analysis in order to define incipient combustion processes of biomass [14,38,39] and coals [40].”

“The data obtained from these analyses allowed the calculation of the apparent activation energy using Cumming’s equation (1) [41], where the first order of kinetics is applied to the rate of weight loss:”

“Measuring particle size for biomass can present problems, due to the shapes of the biomass particle not only when presented in coarse size, but also after milling [45].”

“It has been noticed that small quantities of moisture may help the reaction as the reabsorption of moisture is an exothermic process that might accelerate the increase of temperature in a self-heating process [22].”

“This method has been used previously to characterize the self-ignition of agricultural materials stored in silos [15,16], coals with different ranges and origin [17], biomasses [18], and thermally dried sewage sludge [19], among others.”

“• Aerobic or anaerobic bacterial fermentation [4].”

“This method has been used previously to characterize the self-ignition of agricultural materials stored in silos [15,16], coals with different ranges and origin [17], biomasses [18], and thermally dried sewage sludge [19], among others.”

“To determine the beginning of the process, different methods have been developed, most of them based on thermal analysis techniques, as thermogravimetry and differential scanning calorimetry [9,10], as well as experimental techniques based on thermal decomposition [11], emission of flammable volatiles [12], critical s…”

“For solids, the criteria for the classification of substances that experience spontaneous heating is based on the spontaneous ignition temperature of charcoal, which is 50 ◦C for a cubic sample of 27 m3 [37].”

“The influence of moisture on the self-ignition process has been widely studied [23].”

“The results obtained in this test can be contrasted with data previously obtained [46] for the self-ignition temperature (SIT) of wheat dust, whose composition and particle size are similar.”

“Many authors have used thermogravimetry (TGA) and differential scanning calorimetry (DSC) analysis in order to define incipient combustion processes of biomass [14,38,39] and coals [40].”

“Moreover, when a fire is produced by biomass fuel, it is known that the thickness of the flame reaction zone is related to the particle size: As the particle size increases, so does the flame reaction zone thickness [34].”

“Moreover, temperature increases may produce decomposition reactions that enhance the ignition of the substance [1].”

“This method has been used previously to characterize the self-ignition of agricultural materials stored in silos [15,16], coals with different ranges and origin [17], biomasses [18], and thermally dried sewage sludge [19], among others.”

“The behavior of a material layer deposited on a warm surface is different from the behavior of a pile [32], such as an unthreshed grain.”

“Many authors have used thermogravimetry (TGA) and differential scanning calorimetry (DSC) analysis in order to define incipient combustion processes of biomass [14,38,39] and coals [40].”

“• Presence of compounds more oxidizable than the material itself, either because of contamination or naturally (as it happens with the presence of pyrite in coals) [3].”

“When the material is stored in big piles, the accessibility of oxygen to the inner surface of the material may be reduced, and the oxidation reaction may be delayed [30].”

“Research regarding numerical simulations has also been carried out [20,21].”

“When the product is deposited as a layer or as a great pile, the importance of granulometry is not so obvious [28].”

“To determine the beginning of the process, different methods have been developed, most of them based on thermal analysis techniques, as thermogravimetry and differential scanning calorimetry [9,10], as well as experimental techniques based on thermal decomposition [11], emission of flammable volatiles [12], critical s…”

“Gas emission analysis has been used before assessing oxidation processes related to self-heating and self-ignition of biomasses [42,43].”

“Using a new methodology, it is possible to determine early oxidation processes [44].”

“To determine the beginning of the process, different methods have been developed, most of them based on thermal analysis techniques, as thermogravimetry and differential scanning calorimetry [9,10], as well as experimental techniques based on thermal decomposition [11], emission of flammable volatiles [12], critical s…”

“Some models of particle size effect have been developed [26,27], but not considering self-ignition processes.”

“Research regarding numerical simulations has also been carried out [20,21].”

“To determine the beginning of the process, different methods have been developed, most of them based on thermal analysis techniques, as thermogravimetry and differential scanning calorimetry [9,10], as well as experimental techniques based on thermal decomposition [11], emission of flammable volatiles [12], critical s…”

“• Gaseous substance fixation, as the adsorption or condensation heat is high [5].”

“In this study, the temperature of combustion induction and maximum weight loss, which is related to the reactivity of the sample [29], were obtained from performing thermogravimetry analysis (TGA).”

“Indeed, it has been shown previously that for a fixed bulk density of a material (powders), the combustion rate tends to increase with decreasing particle size [53-54].”

“The goal of pelletization is to make biomass fuel pellets more durable, so that they can be transported without loss of mass to produce small, potentially flammable particles (27).”