Abeth Novria, a doctoral student from the Department of Mechanical Engineering at the Faculty of Engineering, Universitas Indonesia (FTUI), completed his postgraduate studies during the open doctoral promotion session held at FTUI on Wednesday (June 4). Abeth researched innovative gasification technology that converts palm oil waste into renewable energy.
Oil palm fronds are one of the abundant by-products of Indonesia’s palm oil industry. Unfortunately, this waste is often left to rot on plantations, causing environmental issues such as pest infestations and soil contamination. In fact, palm fronds have significant potential as a renewable biomass fuel. One promising technology for converting biomass into energy is gasification, particularly using the bubbling fluidized bed (BFB) system, which can transform organic waste into synthetic gas (syngas) with high energy content.
“Environmentally friendly gasification technology can convert unmanaged palm oil waste into energy. This study investigates the effects of low reactor temperature, equivalence ratio, and biomass particle size on syngas composition using a bubble cap air distributor,” Abeth explained in his presentation.
He developed and optimized this technology in his dissertation entitled “Experimental Study of Syngas Production from Fluidized Bed Gasification of Oil Palm Fronds Using a Bubble Cap Air Distributor at Low Temperature.” The research involved experimental studies on syngas production from gasifying palm fronds using a specially designed bubbling fluidised bed (BFB) reactor.
“The main innovation in this study is the use of a sintered-type bubble cap air distributor, which functions to evenly distribute the airflow and maintain stable bubbling behavior in the reactor. The biomass fuel used consisted of palm fronds in two sizes: powder (420 µm) and pellets (4.25 × 12.78 mm), with silica sand serving as the bed material. The gasification process was conducted at a low temperature of 600°C, with preheated air at 300°C and an equivalence ratio (ER) of 0.32,” Abeth added.
The experimental results showed that the reactor design produced promising syngas composition: 18.97% hydrogen (H₂), 15.26% carbon monoxide (CO), 16.90% methane (CH₄), and 28.91% carbon dioxide (CO₂) by volume. The lower heating value (LHV) of the syngas reached 12.39 MJ/Nm³. Additionally, the carbon conversion efficiency was recorded at 71.97%, cold gas efficiency at 79.53%, and the H₂/CO ratio at 1.24. These results demonstrate that low-temperature gasification can still produce high-quality syngas, especially from palm frond waste.
“However, this research also observed the formation of agglomeration—clumping of particles in the bed material—caused by interactions between alkali metals such as potassium (K), calcium (Ca), and magnesium (Mg) from the ash and the silica sand. Even at low operating temperatures, these interactions triggered chemical transformations that led to agglomerate formation, which could potentially disrupt fluidisation stability. Therefore, ash characteristics and post-gasification chemical interactions are key considerations in the further development of this technology,” Abeth explained.
The findings of this study demonstrate that engineering the bubble cap air distributor design can enhance the performance of the bubbling fluidized bed gasification system, even at low temperatures. This technology offers a practical and efficient solution for processing agro-industrial waste into renewable energy. Furthermore, the study contributes to the development of more stable, efficient, and environmentally friendly gasification reactor designs, paving the way for potential industrial-scale applications in the future.
Abeth graduated with a perfect GPA of 4.00 and received the Cum Laude distinction. He is the 116th doctoral graduate from the Department of Mechanical Engineering and the 596th doctoral graduate overall. The open doctoral defense was chaired by Prof. Dr. Kemas Ridwan Kurniawan, S.T., M.Sc., with Prof. Dr. Ir. Adi Surjosatyo, M.Sc. as the primary supervisor, and Ahmad Syihan Auzani, S.T., M.T., Ph.D. and Prima Zuldian, S.T., M.T., M.Eng., Ph.D. as co-supervisors. The examination committee included Prof. Dr. Ir. Warjito, M.Sc., Ph.D., Prof. Ir. Yulianto Sulistyo Nugroho, M.Sc., Ph.D., Prof. Dr. Ir. I Made Kartika Dhiputra, Dipl.-Ing., and Prof. Dr. Ir. Rizal Alamsyah, M.App.Sc.
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