• Energy Research
• 13. Climate action close
• 12. Responsible consumption close
• University of North Sumatra close

AbstractIn the present paper a study on the performance of clothes drying cabinet by utilizing waste heat from a split-type residential air-conditioner (RAC) has been carried out. A drying cabinet with a volume of 1m3 has been designed and fabricated. The waste heat from the condenser of the RAC with power of 800W was utilized as a heat source. In the experiments, the RAC was operated to keep a conditioned space at 20°C. The clothes dried made of pure cotton with initial weight varied 3.05kg, 5.25kg, 6.21kg, 8.22kg, and 10.22kg. Two different inlets, single inlet and multi-inlets, has been tested. The results show that the drying time varies from 80 to 410min. For single inlet the averaged drying time, optimum initial weight, optimum drying rate and optimum SMER was 242min, 6.21kg, 0.868kg/h, and 2.345kg/kWh. On the other hand, the drying chamber with multi-inlets the averaged drying time, optimum initial weight, optimum drying rate and optimum SMER was 222min, 8.22kg, 0.922kg/h, and 2.492kg/kWh. Thus, the present drying cabinet should be operated with multi-inlets and the initial weight varies from 6 to 8kg.

Abstract This work studied experimentally the performance and exhaust gas emission of a diesel engine coupled with a catalytic converter run on dual-fuel mode using refined biogas resulted from agricultural waste. The content of methane on the biogas is 70%. The experiments were carried out at constant load 1500 kW. The engine rotation varies from 1000 rpm to 1500 rpm. The biogas flow rate varies from 0 to 6 L/min. The output power of the engine operated on dual-fuel mode is better than the engine operated with pure diesel. The brake thermal efficiency of the diesel engine with flow rate of 2 L/min and 4 L/min is better than diesel only. The specific fuel consumption of the diesel engine operated on dual-fuel mode is higher than pure diesel mode. The opacity number of the engine operated on dual-fuel mode is better than pure diesel mode. However, the CO number and HC number of the engine operated on dual-fuel mode are higher than pure diesel mode. The diesel replacement ratio is within the range 15.6% % to 74.8%. It is recommended to run the present diesel engine in dual fuel mode with biogas flow rate 2 L/min - 4 L/min.

 Indonesia is a maritime country that has a sea area of ​​5.8 million km², with enormous potential for marine products. The fisheries sector is one of the things that supports the third largest Indonesian economy with a GDP (Gross Domestic Product) of Rp 1.900 billion. There are many fishery ports in Indonesia commonly referred to as Fish Landing Base. In North Sumatra itself, there are 23 Fish Landing Base, and one of the areas that include it in the RTRW (Regional Spatial Plan) is Serdang Bedagai Regency, especially in Cermin Beach sub-district. However, the fact that the fisheries sector is not the main attraction of the Pantai Cermin area indicates no fishery center. This Fish Landing Base uses problem-solving to solve existing problems, starting from the formulation stage, location surveys, data collection, literature studies, and comparative studies. To respond these issues, ecological architecture becomes the answer to the problem of design conditions, such as responding according to local conditions both from society and nature. Fish Landing Base in Pantai Cermin expect to respond to users comfortably, creates interaction between users and the environment, and can also form a public space so that it can encourage economic generators based on sources of life in coastal areas, and so become one of the new tourist destinations to enjoy the marine products of Indonesia, especially in Serdang Bedagai, North Sumatera.

Food Estate is a government program as a solution to meeting food demand. However, in order to meet food needs, environmental impacts must be considered. The study objective was to investigate the impacts of shallot production in Food Estate Hutajulu, Indonesia. The study was conducted with the first stage determining the functional unit, namely an area of 0.2 hectares with a gate-to-gate scope. The second is the inventory data analysis by grouping the categories of nursery, tillage, maintenance, harvesting, and transportation. The third is life cycle impact assessment (LCIA) according to the ISO 14044 standard. Every data obtained from each process was processed using the software OpenLCA 1.11.0; the following is the workflow and use of the software. Processes were made based on the five categories of data (soil processing, planting, maintenance, harvesting and transportation), which had been determined to be connected to flow. The product system was adjusted according to the data in each process and then calculated, and the results of calculation data and graph models appear from each processed data category. Fourth is the interpretation that considers the highest environmental impact, namely acidification in the transportation process of 1.8974 kg SO2 eq, global warming potential in the transportation process of 415.3188 kg CO2 eq, eutrophication in the transportation process of 0.4364 kg PO4 eq, and human toxicity in the maintenance process of 1,409.07377 kg 1,4-DB eq. To minimize the impact on subsequent production, reducing diesel fuel, chemical pesticides and chemical fertilizers are recommended.

Abstract Water plays an essential part in human life. In our daily activities, water is something we must consume for our survival. As one of the largest seawater resources country in the world does not guarantee Indonesian citizens of having pure water to consume. Since, most of the water is already polluted by factories, industries and households. The needs of pure water are increasingly needed as the human population gradually increased. One of the technology to produce pure water is solar distillation. This research aims to find out the water productivity results and the efficiency of glass cover cooling by flowing water over the glass cover on passive double slope solar still. The results showed that the actual and theoretical water productivity calculation for this method are 4,36 liters and 7,57 liters. The efficiency for actual and theoretical of the system 52,32% and 90,88% respectively.

Abstract Oil palm shell and empty fruit bunch (EFB) are biomass which contains lignocellulose which can potentially converted to bio-oil (liquid product of pyrolysis). Pyrolysis process produces solid, liquid and gas products. Temperature level of pyrolysis process influences bio-oil composition and its characteristics. The objective of this research was to characterize bio-oil of pyrolysis product on palm oil shell and empty fruit bunch at 3 different temperature levels. Pyrolysis process was done by using mini pyrolysis reactor. The temperature was set at 400°C, 500°C and 600°C. The result showed that mass fraction of palm oil shell was fluctuating along with the temperature difference. Shell solid fraction was decreasing at range 44.27-34.99% while shell liquid and gas fraction were increasing at range 38.33-43.28% and 17.40-21.73%, respectively. EFB products mass fraction was fluctuating at range 30.66-45.28%, 24.85-29.16% and 28.86-44.49% for solid, liquid and gas respectively. The highest shell bio-oil calorific value was 36.15 kJ/g at temperature 500°C and EFB highest bio-oil calorific value was 40.86 kJ/g at temperature 600°C. The highest shell and EFB bio-oil energy was 7,445.39 kJ and 1117.62 kJ.

This paper aimed to provide a narrative review of the current conditions of orangutan ecotourism on Sumatra Island, problems in the current management systems, and some recommendations for further development. Orangutan conservation centers have been developed on Sumatra Island since 1973. The Bukit Lawang Conservation Station is one of the orangutan conservation centers that have practiced ecotourism to overcome ecological and socio-economic issues. Even though the Bukit Lawang Conservation Station has operated for decades, this station has faced several issues, in particular a monetary crisis in 1997, a flash flood in 2003, and the COVID-19 pandemic. We identified that orangutan conservation centers on Sumatra Island have the potential to support orangutan ecotourism. These conservation centers have ecological support, available facilities, and rich local wisdom that can provide added value for orangutan ecotourism. Therefore, we propose that the development of orangutan ecotourism on Sumatra Island should accommodate surrounding communities through community-based wildlife ecotourism. We also recommend the following strategies to develop orangutan ecotourism on Sumatra Island: (1) mapping the location and distribution of wild orangutans in their natural habitats; (2) managing captive and semi-captive orangutans in conservation centers; (3) provision of tour packages; (4) community empowerment; (5) institutional strengthening of community-based ecotourism management (CBEM); (6) developing ecotourism through a benefit-sharing model; (7) anticipating and minimizing the negative impacts of ecotourism on orangutans; and (8) integrating orangutan tourism with local wisdom.

Purpose The purpose of this paper is to determine the effect of the industrial sector, renewable energy consumption and nonrenewable energy consumption in Indonesia on the ecological footprint from 1990 to 2020 in the short and long term. Design/methodology/approach This paper uses vector error correction model (VECM) analysis to examine the relationship in the short and long term. In addition, the impulse response function is used to enable future forecasts up to 2060 of the ecological footprint as a measure of environmental degradation caused by changes or shocks in industrial value-added, renewable energy consumption and nonrenewable energy consumption. Furthermore, forecast error decomposition of variance (FEVD) analysis is carried out to predict the percentage contribution of each variable’s variance to changes in a specific variable. Granger causality testing is used to enhance the analysis outcomes within the framework of VECM. Findings Using VECM analysis, the speed of adjustment for environmental damage is quite high in the short term, at 246%. This finding suggests that when there is a short-term imbalance in industrial value-added, renewable energy consumption and nonrenewable energy consumption, the ecological footprint experiences a very rapid adjustment, at 246%, to move towards long-term balance. Then, in the long term, the ecological footprint in Indonesia is most influenced by nonrenewable energy consumption. This is also confirmed by the Granger causality test and the results of FEVD, which show that the contribution of nonrenewable energy consumption will be 10.207% in 2060 and will be the main contributor to the ecological footprint in the coming years to achieve net-zero emissions in 2060. In the long run, renewable energy consumption has a negative effect on the ecological footprint, whereas industrial value-added and nonrenewable energy consumption have a positive effect. Originality/value For the first time, value added from the industrial sector is being used alongside renewable and nonrenewable energy consumption to measure Indonesia’s ecological footprint. The primary cause of Indonesia’s alarming environmental degradation is the industrial sector, which acts as the driving force behind this issue. Consequently, this contribution is expected to inform the policy implications required to achieve zero carbon emissions by 2060, aligned with the G20 countries’ Bali agreement of 2022.

AbstractEnzymatic transesterification reaction of degummed palm oil (DPO) in ionic liquid system has been demonstrated in producing biodiesel. Ionic liquid as a supporter of enzyme create a catalytic system that can be used in the transesterification of oil into biodiesel. Recycled Lypozime RM IM to produced biodiesel from DPO as feedstock in ionic liquid system has been investigated. In this research, synthesis of biodiesel from DPO through transesterification (using of methanol as acyl acceptor) and recycled Lipozyme RM IM as catalysts in ionic liquid [BMIM] [PF6] system is conducted in a batch reactor to obtain biodiesel as product were analyzed using Gas Chromatography (GC). As a study in this research, discussed the influence of ionic liquids to performance of Lypozime RM IM or decreasing of lipase activity while recycled that seen from the acquisition yield of biodiesel as a result. The best result in ionic liquid system with ratio of DPO to ionic liquid 1: 1.5 (molar ratio) showed that decreasing lipase activity obtained in this research was about 4.28% (yield from 68.98% to 56.12%) after 4 times with the conditions of 1:3 molar ratio, temperature of reaction 45°C and amount of Lipozyme RM IM was 30%, and 6hours reaction time.