Investigation of briquette derived from Pterocarpus indicus leaves and rejected pineapples as inedible sources of renewable energy

Abstract The previous studies have shown the potential of using Pterocarpus indicus leaves, which are wastes, as biomass material for briquette production. However, the use of tapioca as a binder may negatively affect the availability of food resources. An alternative to tapioca was proposed in this study by substituting it with rejected pineapples which are considered as wastes. Series of investigations were conducted to understand the potential of briquette made of Pterocarpus indicus leaves with rejected pineapple as the binder. The investigations included bomb calorimeter test to determine the proportion of biomass to the binder that generates the highest calorific value, the proximate and ultimate analyses, and the investigation of optimum particle size of biomass and condensing pressure related to the briquette’s combustion characteristics. The results showed that 95% biomass and 5% binder to have the largest calorific value of 4169.76 kcal kg−1. Results from both proximate and ultimate analyses endorse the use of rejected pineapple as a substitute for tapioca binder. Briquette with the optimal combustion characteristics was obtained with condensing pressure of 2 MPa and biomass size of 60 mesh (250 μm).