Investigation on the combustion characteristics of different plant parts of Cassia siamea by DSC-TGA

Plant parts like root, wood, twig and leaf of Cassia siamea, a fast-growing tree in the abandoned mines of Jharkhand, India, have been considered here as a possible fuel source for decentralized power generation. This is a low greenhouse gas emission pathway to cater the electricity need of the adjoining locality. Seasonal availability of the plant parts originated interests of studying the basic combustion characteristics of the plant parts separately. Finding out the roles of cellulose and lignin to regulate the combustion behavior of plant parts was another objective. Cellulose and lignin were extracted from each plant part, and their burning performances were evaluated against those of respective plant parts with the help of DSC-TGA. Cellulose and lignin were found to influence the combustion processes of plant parts differently. Lignin in case of leaf combustion and cellulose for wood combustion regulated the combustion process. Both lignin and cellulose were competitive in regulating the combustion of twig and root. Burning characteristics of cellulose or lignin extracted from different plant parts varied. Higher heating value (HHV) was low for celluloses (~ 16.8 ± 1 MJ kg) as compared to lignin (HHV ~ 23.0 ± 1 MJ kg). Leaf having substantial lignin and extractives showed the highest HHV around 23.5 MJ kg, while the lowest HHV (16.0 MJ kg) was observed for wood. Results are interesting for considering each plant part as a single fuel or as a potential component of coal–biomass blended fuel, where locally available low-grade high ash coal may be the other component.