Fredy Surahmanto, Revando Ardhantano, Deliawan, Andhita Mustikaningtyas, Nashrul Chanief Hidayat
Coconut shell is one kind of biomass resource that is abundantly available in Indonesia. This resource must be handled properly so it would not impact environmental problems. Coconut shell biomass can be processed by carbonization to become biochar which has a higher calorific value. This study aimed to characterize the carbonization process of coconut shells in an inverted downdraft-type gasifier by varying the input airflow speed. The airflow speeds used in the carbonization process were 5 m/s, 8 m/s, and 12 m/s. The experiment of the coconut shell carbonization process with different air flow rates showed that the increasing air flow rate produces a faster time of carbonization. The higher airflow speed resulted in a higher carbonization temperature which indicated a faster carbonization of the coconut shells. The carbonization rate increases in parallel to a shorter duration of carbonization and a larger amount of fuel mass burned. In addition, the char yields were 43 %, 32 % and 34 % for air speeds of 5 m/s, 8 m/s, and 12 m/s respectively. Moreover, the calorific value of coconut shell char is 21% higher than its raw material. © 2025 Author(s).
Department of Mechanical Engineering Education, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia; Undergraduate Student of Manufacture Engineering Study Program, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia; Applied Bachelor of Mechanical Engineering, Faculty of Vocational, Universitas Negeri Yogyakarta, Yogyakarta, Indonesia
