Indonesia is a tropical country located in Southeast Asia. Indonesia has a lot of variety of plant species which are very useful for life. Pterocarpus indicus are commonly used as greening and easily found everywhere in Surabaya city because of its characteristics that they have dense leaves and rapid growth. Pterocarpus indicus leaves waste would be a problem for residents of Surabaya and disturbing the cleanliness of the Surabaya city. Therefore, the Pterocarpus indicus leaves waste would be used as biomass briquettes. This research investigated the calorific value of biomass briquettes from the Pterocarpus indicus leaves waste, the effect of tapioca as an adhesive material to the calorific value of biomass briquettes from the Pterocarpus indicus leaves waste, the optimum composition for Pterocarpus indicus leaves waste biomass briquette as an alternative renewable fuel and the property of the optimum resulted biomass briquette using ultimate analysis and proximate analysis based on the ASTM standard. The calorific value biomass briquettes from the Pterocarpus indicus leaves waste were performed using an oxygen bomb calorimeter at various composition of Pterocarpus indicus from 50% to 90% rising by 10% for each experiment. The experimental results showed that the 90% raw materials (Pterocarpus indicus leaves waste)-10% adhesive materials (tapioca) mixtures is the optimum composition for biomass briquette Pterocarpus indicus leaves waste. The lower the percentage of the mass of tapioca in the biomass briquettes, the higher calorific value generated.
