Ash Composition in Cassava Stems Originating from Different Locations, Varieties, and Harvest Times

The influence of growth location, variety, and harvest time on ash composition and calorific value of cassava stems was evaluated using 180 samples from a full factorial-designed experiment (three locations × three varieties × five harvest times) in Guangxi, China. The calorific value of cassava stems showed only small variations (1500 °C), which was consistent with our published results , and suggested limited sintering during combustion, if any. K and Cl contents varied the most and did so significantly between locations (growth environments), which was attributed to differences in soil composition. On the basis of theoretical and empirical indices of molar ratios, cassava stems across all treatments generally exhibited a risk of particle emissions when combusted but stems from one location (Heng) could have much better combustion behavior than those from others in terms of slagging and corrosive Cl-rich deposit tendencies indicated by the indices K/(Ca + Mg) and combinations of S/Cl and Cl/(K + Na), respectively. Stems from Wuming showed a higher risk for the induction of particle emission, according to the index (K + Na + Ca + Mg)/(P + Si), while biomass from Longan and the variety Xinxuan048 tended to show risk of forming corrosive Cl-rich deposits.