Experimental studies of thermal activity processes of cropped seeds of oil cultures

Abstract

We’ve conducted experimental studies of thermal activity processes with crushed seeds of oil crops, in particular rapeseed, soybean, sunflower of fractions I) > 1 < 2 mm; II) > 0.45 < 1 mm; III) > 0.1 < 0.45 mm, respectively. The results of experimental studies showed that the ignition/self-ignition temperatures of crushed rapeseed, soybean and sunflower seeds for fractions > 1 < 2 mm; > 0.45 < 1 mm; > 0.1 < 0.45 mm do not change and have a value of 322 ± 2/345 ºС; 293 ± 2/415 ºC and 222 ± 2/365 ºC, respectively. The fraction > 0.45 < 1 mm was selected for the study of the thermal stability of oilseeds by thermogravimetric analysis, as it showed the most dangerous temperature values in studies of ignition and self-ignition temperatures. The results of the experimental studies showed that endothermic processes occur in the studied samples of crushed rapeseed, soybean, and sunflower seeds in the temperature range of 20-245 ºC, which was accompanied by a loss of sample mass. Intensive destruction of samples, accompanied by a rapid loss of mass, begins at temperatures of 235-245 ºC. In the temperature range of 235-459 ºC, exothermic oxidation processes occur, which end in the flaming combustion of decomposition products, and at temperatures above 406-459 ºC, the carbonized residue of the samples burns, which is accompanied by the appearance of rapid exo-effects. Studies of the effect of dispersion on the thermal stability of crushed oil cultures seeds showed that the degree of samples grinding does not significantly affect the temperature of the onset of thermo-oxidative destruction. However, the processes of flame combustion of pyrolysis products in the sample with a high degree of dispersion proceed more intensively, and the combustion of the carbonized residue of the sample with a higher degree of grinding is accompanied by a greater release of heat.