Leuser Journal of Environmental Studies

Optimizing Potential Supply Chain of Biomass Agricultural Waste for Co-firing of Coal Power Plant Using MCDA, GIS, and Linear Programming in the Java and Sumatra Islands, Indonesia

2025-04-29T22:15:07+07:00

The development of renewable energy is a key priority for the Indonesian government and many other nations. Utilizing biomass as a co-firing fuel in coal-fired power plants (PLTUs) offers a viable pathway to meet renewable energy targets in the electricity sector. Co-firing technology involves substituting coal with biomass at specific ratios while maintaining the operational quality and efficiency of the power plants. Indonesia plans to implement a co-firing program in 114 PLTUs, with a combined capacity of 18.1 GW, requiring approximately 9 million tons of biomass annually. This study aims to develop a biomass supply chain model for co-firing, focusing on transportation cost optimization. Geographic Information Systems (GIS), Multi-Criteria Decision Analysis (MCDA), and Linear Programming are employed to map biomass potential from agricultural waste, identify optimal storage and factory locations, calculate the shortest distances to PLTUs, and design an efficient supply chain. Key biomass sources considered include agricultural waste from rice, corn, cassava, palm oil, coconut, sugarcane, and rubber. The study concentrates on co-firing in the Java and Sumatra regions, which house 14 and 12 PLTUs, respectively. Assuming a 5% biomass mix, the total annual bio-pellet demand is estimated at 3.34 million tons. By contrast, the annual production capacity of bio-pellets is calculated to be 143.58 million tons, indicating a surplus supply. Optimization results confirm that the available biomass supply can adequately meet the co-firing requirements for PLTUs in Java and Sumatra. The study also identifies optimal locations for storage facilities and bio-pellet factories near PLTU sites, enhancing supply chain efficiency. By integrating data on biomass potential, storage, factory, and PLTU locations, this research facilitates the design of an effective and efficient biomass supply chain, contributing to the broader goal of renewable energy development.

Evaluating the Effectiveness of Community-Based Mangrove Rehabilitation Initiatives

2025-04-29T22:15:05+07:00

Management actions through rehabilitation activities can restore mangrove ecosystems by involving community participation. This study aims to determine the involvement and effectiveness of community-based rehabilitation activities. This study was conducted in Teluk Pambang Village, Bengkalis Regency. The method used is qualitative, with a purposive sampling technique based on certain criteria. The data analysis used is qualitative descriptive and data processing using nvivo 12 plus software. The research findings explain that the dominant factors that encourage people to carry out mangrove rehabilitation activities are based on additional income, strengthening the issue of carbon trade economy, kinship elements, and easy access to financing through donors. The level of program understanding, target accuracy, activity management, and real changes are the most effective rehabilitation activities for the community. At the same time, the indicators for achieving goals are still considered ineffective.

Sustainable Energy Integration in Geothermal Exploration: Conceptual Design and Innovation

2025-04-29T22:15:04+07:00

Geothermal drilling operations in remote areas are commonly powered by diesel generators, leading to high fuel consumption and substantial carbon emissions. This study explores the integration of a hybrid solar PV–diesel generator system to enhance energy sustainability at a geothermal drilling base camp in Indonesia. The system design considers local renewable energy potential and incorporates integration with existing equipment. The integration strategy is evaluated through a feasibility analysis considering system efficiency, energy yield, and environmental impact. Using Helioscope software for solar simulation and load analysis based on equipment specifications, the results show that the PV system can supply up to 35% of the daytime energy demand, reducing daily carbon emissions by 8% and enhancing generator performance through optimized load sharing. Despite the absence of battery storage, the system demonstrates significant environmental and operational benefits, while also highlighting the potential for further improvements through energy storage integration, smart control systems, and targeted energy management.

Improving the Environmental Performance of Palm Biodiesel via AgNO₃-Assisted Removal of Polyunsaturated Fatty Acids

2025-04-29T22:15:02+07:00

Indonesian biodiesel products commonly exhibit low oxidative stability and high cloud points, which limit their performance and widespread use. These drawbacks are primarily due to the high content of polyunsaturated fatty acids (PUFAs) in the fatty acid methyl ester (FAME) mixture that constitutes biodiesel. A more suitable biodiesel composition includes higher proportions of saturated and monounsaturated fatty acids, which offer better combustion properties, higher cetane numbers, and greater resistance to oxidative degradation. In contrast, PUFAs promote oxidation reactions, resulting in fuel instability, increased sludge formation, and higher emissions of unburned hydrocarbons, negatively impacting both engine performance and the environment.This study investigates the use of silver nitrate (AgNO₃) as a selective extraction agent to remove PUFAs from palm oil-derived FAME. The goal is to identify the most effective biodiesel-to-AgNO₃ volume ratio for separating saturated fatty acid fractions from unsaturated ones, in order to produce a more stable and environmentally friendly biodiesel. Experimental results show that a 1:2 volume ratio significantly reduces the iodine number, from 57.22 to 47.38 g I₂/100 g sample, indicating a decrease in unsaturated compounds. Furthermore, oxidative stability improved from 11.18 hours to 11.69 hours after extraction. The removal of PUFAs not only improves the fuel's storage and combustion stability but also enhances its environmental profile. More stable biodiesel burns more completely, reducing emissions of particulate matter and greenhouse gases, and contributing to cleaner air and lower environmental impact. Thus, PUFA extraction using AgNO₃ presents a promising approach for improving the sustainability and performance of palm-based biodiesel fuels.

Resilience and Adaptation: Plant Ecology in Indonesia’s Geothermal Environments

2025-04-29T22:15:00+07:00

Geothermal ecosystems are defined by extreme environmental conditions, such as elevated temperatures, high concentrations of toxic chemicals, and fluctuations in abiotic stressors, which shape plant survival and adaptation. These unique ecosystems, found across various geothermal regions globally, support specialized plant communities that have developed distinctive morphological, physiological, and ecological adaptations. Indonesia, located on the Pacific Ring of Fire, is one of the world’s richest geothermal nations, offering an important yet underexplored context for studying vegetation in geothermal zones. This review examines the environmental conditions of geothermal ecosystems, the adaptive strategies of vegetation, and patterns of plant diversity within Indonesian geothermal fields. It also explores ecological succession, community dynamics, and the potential use of geothermal vegetation as environmental indicators for biomonitoring. Despite growing interest, significant research gaps remain, particularly in long-term monitoring and the integration of molecular-level studies. Addressing these gaps is essential for enhancing scientific understanding and informing conservation and sustainable geothermal energy development in tropical regions. This review highlights the ecological significance of geothermal vegetation and underscores the need for interdisciplinary research to support both biodiversity preservation and responsible energy exploitation.