Effects of carbonization conditions on properties of bamboo pellets

Bamboo is a biomass material and has great potential as a bio-energy resource of the future in China. Bamboo pellets were successfully manufactured using a laboratory pellet mill in preliminary work. This study was therefore carried out to investigate the effect of carbonization conditions (temperature and time) on properties of bamboo pellets and to evaluate product properties. It was concluded that carbonization conditions affected the properties of bamboo pellets. The effects of carbonization temperature on some properties such as unit mass loss, pellet absorption, bulk density, unit density, gross calorific value and combustion rate, were significant at p = 0.05. But there were not significant differences between carbonization time and all properties of bamboo pellets. After being carbonized, the properties of bamboo pellets, such as pellet absorption, durability, fine, gross calorific value, combustion rate and heat release rate, were improved. All properties of carbonized pellets meet the requirement of the Pellet Fuels Institute Standard Specification for Residential/Commercial Densified and the gross calorific value also meets the minimum requirement for making commercial pellets of DIN 51731 (>17,500 J/g) even though the properties of carbonized pellets, such as bulk density, unit density and inorganic ash, had poor quality compared with untreated pellets. Carbonized bamboo pellets are the proposed new biomass solid fuel and have the potential to be developed as commercial pellets.