cover
Contact Name
Agung Premono
Contact Email
jurnalkem@gmail.com
Phone
+6221-4700918
Journal Mail Official
jkem@unj.ac.id
Editorial Address
Rumpun Teknik Mesin, Fakultas Teknik, Universitas Negeri Jakarta
Location
Kota adm. jakarta timur,
Dki jakarta
INDONESIA
Jurnal Konversi Energi dan Manufaktur
ISSN : 23392029     EISSN : 26225565     DOI : https://doi.org/10.21009/JKEM
This journal aims as a medium for lecturers, researchers and practitioners to discuss result of their research in the field of mechanical engineering.
Articles 183 Documents
Performance and Efficiency Comparison of Human Waste Biogas and LPG Production in Modified Water Pump Engines Anggrainy, Rani Anggrainy; Afiah, Syifa Kawakib Nurul; Latiep, Abdul; Sukrawan, Yusep; Noor, Ridwan Adam Muhamad; Nurhaliza, Tiana; Fauzi, Virgi Ahmad; Abdurrahman, Fajar
Jurnal Konversi Energi dan Manufaktur Vol. 10 No. 2 (2025)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.10.2.7

Abstract

As daily needs and fuel prices continue to rise and non-renewable natural resources diminish, alternatives are needed to replace these energy sources with renewable energy. Data from the National Energy Council shows that in Indonesia, only 16.358 household biogas digester units have been installed, or about 1.6% of the total potential that can be utilized. This research aims to compare the performance of biogas from human feces with liquefied petroleum gas (LPG) as fuel for water pump engines. The method used is experimental, involving the modification of the carburetor on the water pump engine, followed by direct measurement and analysis of the water pump results using variations of biogas and LPG fuels. A literature review indicates that biogas has great potential as a renewable energy source, but its utilization in Indonesia remains very limited. In this study, the test variables include variations in pump speed at 3800, 5300, and 6600 rpm. The test results show that the mass flow rate of biogas compared to LPG yields the highest discharge at 6600 rpm (0.118: 0.150 m³/s). For both biogas and LPG fuels, the maximum shaft power of the water pump engine reaches 3.9 kW at 6600 rpm. The maximum waterpower generated by the water pump engine using biogas and LPG is 1.26 kW and 1.6 kW at 6600 rpm, respectively, while the maximum efficiency reaches 32% with biogas and 41% with LPG. Therefore, the higher the water pump engine speed, the higher the values of shaft power, engine power, discharge, and efficiency. The efficiency ratio comparison between biogas and LPG at 6600 rpm is 3:4.
Characteristics of Agricultural and Plantation Wastes as Solid Biomass Energy Feedstock: A Systematic Review Tambunan, Hardiansyah; Safrizal; Fahmi, Mutiara
Jurnal Konversi Energi dan Manufaktur Vol. 10 No. 2 (2025)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.10.2.6

Abstract

The conversion of agricultural and plantation waste into biomass energy represents a promising pathway in the global transition to environmentally friendly energy sources. However, systematic comparisons of different types of agricultural and plantation biomass waste remain limited. This study aims to identify and evaluate the characteristics of various agricultural and plantation wastes to determine their feasibility as solid biomass energy feedstock. A systematic literature review was conducted using databases such as PubMed, DOAJ, and manual searches, focusing on articles published between 2014 and 2025. A total of 32 relevant studies were selected based on inclusion criteria. The analysis revealed that coconut shells, coffee grounds, and oil palm kernel shells possess superior fuel properties, particularly high calorific values of ≥ 4000 cal/g, making them highly suitable for solid biofuel production. These findings emphasize the strategic potential of agricultural and plantation waste as a sustainable energy source. The study contributes to the advancement of circular economy practices, promotes effective waste management, and supports the achievement of Sustainable Development Goals (SDGs).
The Effect of Hardening Process on SKD 61 Material using Single Quenching and Double Quenching Techniques on Its Mechanical Properties Wiradinata, Trisna Ardi; Nopryandi; Daryus, Asy'ari; Bagas, Stefanus; Sugiyanto, Didik
Jurnal Konversi Energi dan Manufaktur Vol. 10 No. 2 (2025)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.10.2.8

Abstract

This study focuses on investigating the effects of Single quenching and double quenching techniques on the mechanical properties of SKD 61 material, particularly in the context of bending strength and hardness measured using the Brinell hardness test. The research method involved heating SKD 61 specimens to 1000°C for 15 minutes, followed by cooling using oil and air as quenching media. The results showed that the single quenching technique with oil medium increased the bending strength from 406.89 to 435.84 N/mm² and the hardness from 255 to 315 HB. The single quenching technique using air increased the bending strength to 410.88 N/mm² and the hardness to 290 HB. Meanwhile, the double quenching technique using a combination of oil and air produced a bending strength of 430.08 N/mm² and a hardness of 305 HB. These improvements are based on average values, and no statistical significance testing was conducted. These findings suggest that the appropriate selection of quenching media can optimize the mechanical properties of SKD 61, which is crucial for industrial applications requiring a combination of high toughness and strength.
Heat Pump Drying of Arabica Coffee Beans: Influence of Inlet Air Conditions on Drying Rate Constant Hanifah, Muhamad Abu; Kosasih, Engkos Achmad; Fauzi, Muhammad Burhanuddin
Jurnal Konversi Energi dan Manufaktur Vol. 10 No. 2 (2025)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.10.2.5

Abstract

Drying is a crucial step in agricultural processing as it reduces moisture content, extends shelf life, and preserves product quality. For heat-sensitive Arabica coffee beans, heat pump drying (HPD) is an efficient and energy-saving method. This study investigates the drying characteristics of wet Arabica coffee beans using an HPD system, focusing on determining the drying rate constant (k) at various inlet air temperatures and humidity conditions. The drying process was conducted for 30 minutes at a constant air mass flux rate of 0.69 kg/m²-s at temperatures of 45, 50, 55, 60, and 65°C. Inlet air conditions were controlled with a cooling system at 10, 15, and 20°C, compared to ambient air without cooling. The results showed that increasing drying temperature and decreasing inlet air humidity significantly enhanced the drying rate. Additionally, the study explored the relationship between the constant air mass flux and variable parameters, including air temperature and humidity, which directly affected the drying rate constant (k). The highest k value (17.66 × 10⁻⁵ s⁻¹) was observed at 65°C with air from the cooling system at 10°C, indicating that combining high temperature and dry air improves drying efficiency.
Comparative Analysis of Taper and Taperless Horizontal Turbine Blades at Labuhan Jukung Beach Buana, Setiadi Wira; Prakoso, Yudhistira Alghifari; Kencana, Elsa Rizkiya; Yunesti, Putty; Wardani, Wulan Kusuma; Persada, Guna Bangun; Madi
Jurnal Konversi Energi dan Manufaktur Vol. 10 No. 2 (2025)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.10.2.10

Abstract

The uneven distribution of electricity demand across Indonesia necessitates the development of Renewable Energy Sources, particularly wind energy. This study evaluates the performance efficiency of horizontal-axis wind turbines equipped with two blade types: taper and taperless, both using the NACA 0012 airfoil. Aerodynamic simulations were conducted using QBlade software. Wind speed data from 2017 to 2022 were sourced from the European Centre for Medium-Range Weather Forecasts (ECMWF), while electricity consumption data were obtained from the Statistics Bureau of Pesisir Barat Regency. A quantitative approach using descriptive graphical analysis was employed to compare the performance metrics of the two blade designs. The results show that the taperless blade achieves higher power coefficient (Cp) and torque coefficient (Ct) values compared to the taper blade, although the taper blade produces greater torque (T). The energy conversion of the taperless blade reached 347.6 kWh, representing an increase of approximately 4.83% over the 331.6 kWh generated by the taper blade. Further analysis indicates that approximately 19 taperless-blade turbines are required to meet the daily electricity demand of 6,545 kWh in Pesisir Barat Regency. These findings support the recommendation to adopt taperless blades for improved wind energy utilization in the region.
Effect of SMAW Process Parameters on Hardness, Temperature Distribution, and Micro–Macro Structure of A36 Steel Welded Joints Nursyifaulkhair, Desrilia; Priyambodo Nur Ardi Nugroho; Wardani, Dianita; Kharismajid , Kharismajid; Al Amin , Mochammad Karim; Khazi , Muhamad Eko Nur
Jurnal Konversi Energi dan Manufaktur Vol. 11 No. 1 (2026)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.11.1.1

Abstract

The outer shell of an ISO tank plays a critical role in maintaining the integrity of its contents by withstanding temperature fluctuations, pressure, and radiation. Research on the fabrication of liquefied natural gas (LNG) tank outer shells therefore provides both scientific and practical value, particularly in ensuring mechanical reliability and structural performance. This study investigates the welding of American Society for Testing Materials (ASTM) A36 steel plates using shielded metal arc welding (SMAW) and evaluates the effect of welding parameters on mechanical and microstructural properties. Four specimens were prepared by varying welding current at 70 and 80 A on plate thicknesses of 4 and 12 mm. The results indicate that both current and thickness significantly influence the weld zone microstructure, with transformations from ferrite–pearlite in the base metal to widmanstätten and acicular ferrite in the weld metal. In terms of mechanical performance, the highest hardness value of 198.387 HVN was recorded in the 4 mm specimen welded at 70 A, demonstrating the strong dependence of hardness on combined current and thickness conditions. These findings contribute to optimizing welding parameters for the safe and reliable application of LNG tank outer shells.
Development of a Portable Laser Engraving System for Small-Scale Manufacturing Applications Budiono, Herru Santosa; Purnomo, Sigit Joko; Gastiadirrijal, Muhammad Naufal; Setio, Wawan
Jurnal Konversi Energi dan Manufaktur Vol. 11 No. 1 (2026)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.11.1.3

Abstract

The portable laser engraving system developed in this study integrates an APM32F103 microcontroller, external flash memory (25Q128JV), and an FSC-BT986 Bluetooth module with an Android-based engraver application. The system is designed to address limitations of bulky and costly commercial engravers by offering a compact, low-cost, and wireless alternative for educational laboratories and small-scale manufacturing. Mechanical and electronic subsystems were designed and fabricated using a knockdown frame structure and 3D-printed components. Performance evaluation included functionality testing, wireless communication stability, motion accuracy, and engraving capability on wood, MDF, acrylic, and synthetic leather. The results show stable Bluetooth communication within an effective range of 8 m, an average motion accuracy error of 0.82%, and engraving depths ranging from 0.28–0.45 mm depending on material and laser parameters. The proposed configuration demonstrates technical advantages in wireless stability, portability, and ease of use compared to conventional wired microcontroller-based laser engravers.
Current Variation Effect on Hardness and Corrosion Resistance of Formed Weld Layer Syaripuddin; Sopiyan; Nur Hisyam, Ahmad
Jurnal Konversi Energi dan Manufaktur Vol. 11 No. 1 (2026)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.11.1.4

Abstract

Hardfacing over carbon steel was carried out using the SMAW apparatus. The sample was hard-faced with a single layer using HV 800 electrode with a 1G weld position. Different welding currents were used, such as 90, 100, and 110 A. After the weld, the sample was quickly immersed in distilled water. Cooled samples were cleaned with a chipping hammer and a wire brush. Afterwards, the samples were cut for hardness and corrosion testing. The highest hardness in the sample was welded using 110A, while the lowest hardness was welded using 90A. Increasing the current from 90 to 110 A could increase hardness by approximately 2.31%. The lowest current was used during welding, resulting in a lower corrosion rate. This means that the welding layer produced at the lowest current has greater corrosion resistance than that produced at higher currents. Reducing the current from 110 to 90 A could reduce the corrosion rate by approximately 44.33%. Finally, all three specimens meet the "good" criteria of corrosion resistance. 
Sustainable Energy Transition in Remote Islands: Evaluating Wind–Solar Hybrid Systems to Support Commercial Green Tourism on Kei Kecil Island Fa’alih, Saika Khoolish Rochma; Abdad, Muhammad Rafif Dzaky; Ria, Novita Vadina Marta; Rizkiawan, Wildan Yusril Nurhuda; Trisnoaji, Yuki
Jurnal Konversi Energi dan Manufaktur Vol. 11 No. 1 (2026)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.11.1.2

Abstract

This study aims to analyze the techno-economic feasibility of a hybrid microgrid system designed to support commercial green tourism infrastructure on Kei Kecil Island, Southeast Maluku. The research focuses on evaluating the investment feasibility of adding a 99 kW wind power plant to an existing system comprising photovoltaic (PV), diesel generators, and batteries. The methodology employs HOMER Pro simulation to assess key financial indicators and environmental impacts, with a particular emphasis on carbon emission reduction. Simulation results indicate that the proposed hybrid scenario offers a highly profitable investment strategy, characterized by a high return on investment (ROI) and a rapid payback period of under five years. These findings confirm that integrating wind energy not only significantly increases the renewable energy fraction but also suppresses the cost of energy to a competitive level compared to conventional generation. The novelty of this study lies in the specific analysis of wind turbine intervention on a brownfield architecture in a remote island setting, distinguishing it from typical greenfield design studies. This research provides a significant contribution to policymakers and investors as a validation model for energy transition supporting sustainable tourism in archipelagic regions.
Analysis of Lead Time Reduction in Pre-Delivery Installation Process of Excavator Units at PT. XYZ Assembly Plant Setiawan, Dibyo; Bintaran, Tubagus Syah Fatahillah Gelagah Wangi; Setiawan, Apri; Ardi, Hanni Maksum; Siahaan, Herbert Hasudungan; Wibowo, Cahyo
Jurnal Konversi Energi dan Manufaktur Vol. 11 No. 1 (2026)
Publisher : Universitas Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21009/JKEM.11.1.5

Abstract

The Pre-Delivery Installation (PDI) Department of PT. XYZ is tasked with carrying out the installation process of imported heavy equipment attachment units, including one of the leading excavator units. Obstacles that arise can affect installation productivity. The gap between the actual installation results of 78 units and the company's target of 156 units requires a solution or resolution to improve the process that can be implemented. Therefore, it is necessary to investigate the wait time associated with decreased productivity, which is the longest component of the installation process. This work has a purpose to analyze lead time of the excavator attachment unit installation process. The method is applied with a time study approach referring to data sheets and observations, then processing lead time data using pie charts, Pareto diagrams, and fishbone diagrams. Furthermore, we review the planning calendar, realization, and improvement engineering. Reduction is carried out by providing additional work personnel and procuring sanding machine tools to reduce the installation and critical time of the planning calendar. The realization condition for 562 minutes with the implementation of improvement engineering is reduced to 318 minutes. Thus, it can speed up implementation time of the excavator attachment in unit installation process to 224 minutes or 44%.