Compaction of biomass through pelletization leads to the formation of a carbon neutral fuel with higher
density. The aim of this present work was to determine the extent of influence of pelletizing pressure on
pellet density and alteration of higher heating value (gross heat of combustion) of pellets. Eight species of
wood sawdust and different compression pressures were used in pellet preparation. The sizes and mass
of compressed samples were measured to calculate the pellet density and oxygen bomb calorimeter were
used to determine higher heating value. Pellet density was seen to increase radically at first and then
gradually with the increase of pelletizing pressure. In case of heating value, with increase in pelletizing
pressure no definite trend was observed among the compressed biomass species. The pattern of bonding
between biomass particles is the main factor influencing heat of combustion. The alteration of chemical
composition, quantity of moisture and extractives, prevalence of favourable condition for lignin flow,
migration of extractives to the surface and the presence of inter-particle gaps and voids affect the
bonding quality. These factors differ from one biomass species to another which eventually leads to
variation in higher heating value pattern.