PresentationThis work examined the minimum explosion limit (MEL), minimum ignition energy (MIE), cohesion, dispersibility, decomposition temperature (Td) and burning rates of spent coffee ground (SCG), jatropha kernel (JK) and jatropha shell (JS) were studied. The MIE values of oily SCG containing 21.3 wt% and oil-extracted SCG were 35 and 120 g m-3 , respectively. Moreover, cohesion of oily SCG and oil-extracted SCG were high level and low level, respectively. It was found that MIE of oily SCG containing 21.3wt% of oil was low although high cohesion. While oil-extracted jatropha kernels and shells had MEL values of 45 and 110 g m-3 , respectively. However, Oily JK containing 60.7 wt% of oil was not exploded reason for high cohesion and no form dust cloud. The MIE values of untreated SCG, oil-extracted SCG, oil-extracted JK and JS were found to be >3000, >3000, 1515, and >3000 mJ, respectively. These biomasses were needed high energy ignition for explosion. Burning rates of JK and JS were 0.21 and 0.04 mm s-1, respectively, these values were very slow compared with cellulose used as a reference materials was 0.67 mm s-1. Besides SCG were not capable of ignition. The Td of both untreated SCG and oil-extracted SCG were 240 and 241 °C while the Td of untreated JK (60.7wt% oil), oil-extracted JK, and JS were 195, 189, and 233 ̊C indicating that the ignition temperature is influenced by oil content. Consequently, the results demonstrate that oily solid biomasses such as SCG and jatropha are associated with a high risk of fire, dust explosion, and related incident
