Biofuel and Charcoal Properties of Discarded Aromatic Coconut Residues from Agro-industry

This research aims to utilize four types of discarded aromatic coconut waste, namely coconut shells,  husks, husk with attached shells, and empty fruit bunches obtained from the agriculture industries in Ratchaburi and Samut Songkhram provinces, to analyze their fuel properties and charcoal produced from both a pit kiln and 200-liter drum kiln. The proximate analysis included moisture content, ash, volatile matter, and fixed carbon according to the ASTM D3172-13(2021)e1 standard. The study also evaluated the calorific value using a bomb calorimeter and conducted an ultimate analysis of carbon, hydrogen, oxygen, nitrogen, and sulfur contents. Additionally, the study investigated the potential for briquetting biomass fuel and charcoal using cassava starch as a binder. The results showed minor differences in the high heating value (HHV) of the materials, which varied according to their group and origin. The HHV of the coconut wastes ranged from 17.38 to 20.48 MJ/kg, while the charcoal produced from these materials ranged from 24.14 to 31.84 MJ/kg. The HHV from both kiln types were similar, with coconut shells yielding the HHV, followed by husks with attached shells. The predicted HHV of the charcoal, based on the equation proposed by Demirbas from the proximate analysis data, showed an average deviation of less than 5%, which is practical for applications. The most suitable biomass fuel for briquetting was found to be coconut husk biomass and coconut shell charcoal, as both provided HHVs exceeding 20 MJ/kg.