Article Per Year (5 Year)
p-Index From 2021 - 2026
0.61
P-Index
This Author published in this journals
All Journal Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering)
Fredrik Julius Haba Bunga
Artha Wacana Christian University, Kupang, East Nusa Tenggara, Indonesia
Agriculture, Biological Sciences & Forestry Engineering

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

 1 
Characteristics of Residence Time of the Torrefaction Process on the Results of Pruning Kesambi Trees Jemmy Jonson Sula Dethan; Fredrik Julius Haba Bunga; Mellissa Erlyn Stephanie Ledo; Jemseng Carles Abineno
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol 13, No 1 (2024): March 2024
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtep-l.v13i1.102-113

Abstract

The excessive use of Kesambi (Schleichera oleosa) tree stems threatens the sustainability of Kesambi plants since it takes several decades for them to regenerate new stems. This research aims to determine the characteristics of torrefied Kesambi tree pruning. The used reactor has a diameter of 400 mm. An iron basket is positioned 100 mm above the reactor base, holding the material within an aluminum cylinder. The reactor temperature is maintained at 300°C using a K-type thermocouple sensor. A heater is placed near the reactor base and covered. The characteristics of the semi-charcoal biomass product are identified, including mass yield, water absorption capacity, moisture content (D3173, 2013); ash content (ASTM D1102-84. Standard Test Method for Ash in Wood, 2013); volatile matter (%) (ASTMD3175, 2011); and fixed carbon (%) (ASTM, 2013). The color of the leaves and the pruned Kesambi tree changes from brown to black as the residence time increases. The results of pruning the Kesambi tree at different torrefaction residence times indicate a decrease in mass yield with an increase in residence time, with the lowest mass yield observed at a residence time of 20 minutes. The water absorption capacity of torrefied Kesambi tree pruning material is found to be between 0.65% and 0.675%, or less than 1% and higher heating value (HHV) prediction 29.0750 MJ/kg.Keywords: Kesambi, Pruning, Residence, Time, Torrefaction
Characteristics of Residence Time of the Torrefaction Process on the Results of Pruning Kesambi Trees Dethan, Jemmy Jonson Sula; Haba Bunga, Fredrik Julius; Ledo, Mellissa Erlyn Stephanie; Abineno, Jemseng Carles
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol. 13 No. 1 (2024): March 2024
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtep-l.v13i1.102-113

Abstract

The excessive use of Kesambi (Schleichera oleosa) tree stems threatens the sustainability of Kesambi plants since it takes several decades for them to regenerate new stems. This research aims to determine the characteristics of torrefied Kesambi tree pruning. The used reactor has a diameter of 400 mm. An iron basket is positioned 100 mm above the reactor base, holding the material within an aluminum cylinder. The reactor temperature is maintained at 300°C using a K-type thermocouple sensor. A heater is placed near the reactor base and covered. The characteristics of the semi-charcoal biomass product are identified, including mass yield, water absorption capacity, moisture content (D3173, 2013); ash content (ASTM D1102-84. Standard Test Method for Ash in Wood, 2013); volatile matter (%) (ASTMD3175, 2011); and fixed carbon (%) (ASTM, 2013). The color of the leaves and the pruned Kesambi tree changes from brown to black as the residence time increases. The results of pruning the Kesambi tree at different torrefaction residence times indicate a decrease in mass yield with an increase in residence time, with the lowest mass yield observed at a residence time of 20 minutes. The water absorption capacity of torrefied Kesambi tree pruning material is found to be between 0.65% and 0.675%, or less than 1% and higher heating value (HHV) prediction 29.0750 MJ/kg.Keywords: Kesambi, Pruning, Residence, Time, Torrefaction
Natural Convection and Thermal Stratification in a Biomass Oven Fueled by Non-Carbonized Kesambi Leaf Briquettes: An Experimental Study Jemmy Jonson Sula Dethan; Fredrik Julius Haba Bunga; Erich Umbu Kondi Maliwemu
Jurnal Teknik Pertanian Lampung (Journal of Agricultural Engineering) Vol. 15 No. 2 (2026): April 2026
Publisher : The University of Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/jtepl.v15i2.752-760

Abstract

This study investigates the vertical temperature distribution, natural convection behavior, and thermal performance of a biomass oven fueled by non-carbonized Kesambi leaf briquettes. Temperature measurements were conducted at multiple vertical positions inside the oven to characterize heat distribution and buoyancy-driven airflow during operation. The results show a clear vertical temperature stratification, indicating that heat transfer within the oven is dominated by natural convection without external airflow assistance. Dimensionless analysis revealed Rayleigh numbers on the order of 10⁸–10⁹, confirming the prevalence of buoyancy-induced convection, while the Nusselt number varied dynamically in response to changes in temperature difference and operating conditions. The middle region of the oven (50–60 cm from the base) consistently exhibited the most stable thermal conditions, identifying it as the most effective zone for heat utilization and smoking applications. The thermal efficiency of the oven ranged from 32% to 38%, with variations primarily influenced by combustion intensity and transient heat losses through uninsulated walls and the chimney. These findings demonstrate that non-carbonized Kesambi leaf briquettes can provide stable heat output for biomass ovens and offer practical insights for optimizing oven height, heating zones, and design improvements in small-scale food processing applications.
Co-Authors Erich Umbu Kondi Maliwemu Jemmy Jonson Sula Dethan Jemseng Carles Abineno Ledo, Mellissa Erlyn Stephanie Mellissa Erlyn Stephanie Ledo