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

Abstract Indonesia has an abundance of various types of agricultural products. One of the abundance of agricultural products in Indonesia is cassava, but the skin is rarely used, so it can be a source of waste. Cassava peels can be used as a source of bioenergy in the form of biogas. This research was conducted by mixing the ratio of domestic waste mixing IPAL Cemara PDAM Tirtanadi and water by including cassava peels. In the slurry, cassava peels added about 8-9 % This study aims to determine the amount of biogas produced from bioreactors with and without silica gel as media. The ratio of domestic waste from IPAL Cemara PDAM Tirtanadi and water 1: 0, 1: 0.5, 1: 0.4 1: 0.3. The retention time during 23 days. The parameters tested from this study were COD, TSS, and VS. From the results of the research, it was found biogas from bioreactor ratio of 1: 0. In the bioreactor with silica gel media biogas was found on the 19th day with a pressure of 499.8 Pa, however in bioreactor without silica gel media, biogas was found at 294 Pa.

AbstractTypical adsorbent applied in solar-powered adsorption refrigeration cycle is activated carbon. It is known that activated alumina shows a higher adsorption capacity when it is tested in the laboratory using a constant radiation heat flux. In this study, solar-powered adsorption refrigeration cycle with generator filled by different adsorbents has been tested by exposing to solar radiation in Medan city of Indonesia. The generator is heated using a flat-plate type solar collector with a dimension of 0.5m×0.5m. Four cases experiments of solar-powered adsorption cycle were carried out, they are with generator filled by 100% activated alumina (named as 100AA), by a mixed of 75% activated alumina and 25% activated carbon (75AA), by a mixed of 25% activated alumina and 75% activated carbon (25AA), and filled by 100% activated carbon. Each case was tested for three days. The temperature and pressure history and the performance have been presented and analyzed. The results show that the average COP of 100AA, 75AA, 25AA, and 100AC is 0.054, 0.056, 0.06, and 0.074, respectively. The main conclusion can be drawn is that for Indonesian condition and flat-plate type solar collector the pair of activated carbon and methanol is the better than activated alumina.

Today apartment dwellers generally tend to be individualistic righteously urban middleclass society in general. Unlike the situation in the neighborhood, where the level of socialization on the surrounding community is still quite high due to the surrounding community still likes hanging out with the neighbors, especially in the afternoon. Issues raised here is the lack of socialization that occurs between the residents in the apartment. Garden Living means “life park”. Garden is a garden that is as a place of socialization for residents and surrounding communities. Garden Living itself is to make the park as a place to socialize and interact with fellow residents of the apartment and the garden is also a gathering place for the general public. Lack of facilities to accommodate the occupants to socialize the reason the construction of an apartment that has an garden and is expected to become a place to socialize for the residents of the apartment. For the people who live around the apartment also will be built a public park so that people can still socialize and gather together. Taking the concept of Green Architecture or Sustainable Architecture, the building is minimal in consumption of natural resources, including energy, water, materials, and minimal negative impact on the environment. By the way of utilizing rain water and Deli river water and uses sunlight as a power source. 100406064

Mangroves are an important ecosystem that provides valuable social, economic, and environmental services. Indonesia has placed mangroves on its national priority agenda in an important effort to sustainably manage this ecosystem and achieve national climate commitments. However, mangrove management is faced with complex challenges encompassing social, ecological, and economic issues. In order to achieve the government’s commitments and targets regarding mangrove restoration and conservation, an in-depth study on and critical review of mangrove management in Indonesia was conducted herein. This work aimed to provide a comprehensive analysis of the challenges and strategic recommendations for sustainable mangrove management in Indonesia. SWOT analysis was carried out to understand the strengths, weaknesses, opportunities, and threats related to mangrove management in Indonesia. To address these gaps, we reviewed the existing policies, current rehabilitation practices, environmental challenges, and research and technology implementations in the field. We found that strategies on mangrove ecosystem protection, such as improving the function and value of mangrove forests, integrating mangrove ecosystem management, strengthening political commitments and law enforcement, involving all stakeholders (especially coastal communities), and advancing research and innovations, are crucial for sustainable mangrove management and to support the national blue carbon agenda.

Pests and diseases of oil palm can affect the growth and productivity of fresh fruit bunches. Therefore, it is necessary to have experts who can quickly conclude the types of diseases and how to deal with diseases that attack oil palm plants. Based on research conducted in September, the highest number was attacked by pests and diseases, which amounted to 41.33% this figure is the highest number in 1 year. The cause of the growth of pests and diseases in oil palm plants is caused by changes in climate temperature from summer to winter. From the results of monitoring humidity in September, the average temperature in the month was 32.9 degrees Celsius. The application of an expert system that is applied to a smartphone can help farmers diagnose the symptoms caused by seawit coconut plants early on. So that the spread of pests and diseases can soon be overcome.

Biodiesel production has rapidly grown over the last decades, and it has attracted much attention in the market as fuel that promising substitute for petroleum diesel, because its physical and chemical properties and energy content are similar to those of petroleum diesel. The main problem in producing biodiesel is its high cost which could be reduced by use of less expensive feedstock. Therefore, in this work biodiesel is synthesized by enzymatic esterification from low quality feedstock which is unrefined and much cheaper than the refined oil, such as palm fatty acid distillate (PFAD) with dialkyl carbonate using immobilized lipase (Novozym®435). Enzymatic process has certain advantages over the chemical process, as it is less energy intensive, allowing the esterification of glycerides with high free fatty acid contents (PFAD, 85-95% FFA) and no enzymatic activity loss. Methanol replaced by dialkyl carbonate, especially DMC due to esterification (methanolysis) is close to equilibrium reaction whereas using DMC the intermediate compound immediately decomposes to carbon dioxide and an alcohol, which have been investigated. Moreover, DMC are cheap, eco-friendly chemical, non-toxic properties and widely available. Factors affecting the reaction such as DMC to PFAD molar ratio, reaction temperature, reaction time and catalyst concentration were systematically analyzed by response surface methodology (RSM) with central composite design (CCD). The optimal condition is using 6:1 molar ratio of DMC to PFAD at 60 oC, for a reaction time 3h in the presence 10wt% of catalyst (based on oil weight). The results showed that synthesis of biodiesel through enzymatic esterification using PFAD suitable for biodiesel production.

This investigation scrutinizes the economic features and potential of propylene and methanol production from natural gas in Iran because greenhouse gas emissions released by natural gas-based production processes are lower than coal-based ones. Considering the advantage of Iran’s access to natural gas, this study evaluates and compares the economic value of different plans to complete the value chain of propylene production from natural gas and methanol in the form of four units based on three price scenarios, namely, optimistic, realistic, and pessimistic, using the COMFAR III software. Iran has been ranked as the second most prosperous country globally based on its natural gas reserves. Methanol and propylene production processes via natural gas will lower the release of greenhouse gas. This, increasing the investment and accelerating the development of methanol and propylene production units driven by natural gas will lead the world to a low emission future compared to coal-based plants. The economic evaluation and sensitivity analysis results revealed that the conversion of methanol to propylene is more attractive for investment than the sale of crude methanol. The development of methanol to propylene units is more economical than constructing a new gas to propylene unit because of the lower investment costs.

Récemment, une grande attention a été accordée à l'application des énergies renouvelables dans les questions environnementales. Pendant ce temps, l'industrie des piles à combustible, qui est considérée comme une industrie respectueuse de l'environnement, est l'une des composantes importantes de ce projet. Ce sont en fait des dispositifs pour la conversion directe de l'énergie chimique en énergie électrique par une réaction électrochimique sans avoir besoin de pièces mécaniques. Dans cette étude, on tente de modéliser l'un de leurs types importants, appelé pile à combustible à membrane échangeuse de protons, afin qu'il puisse être utilisé pour prédire le comportement de la pile à combustible et examiner divers paramètres affectant les performances de la pile. L'idée principale est d'estimer les paramètres optimaux pour les piles à combustible à membrane échangeuse de protons en minimisant la valeur d'erreur quadratique totale entre la tension de sortie empirique et la tension de sortie approchée. Pour donner de meilleurs résultats en termes de précision et de fiabilité, une nouvelle conception d'une métaheuristique appelée l'algorithme équilibré Water Strider est utilisée. Les résultats de la méthode suggérée sont finalement validés par comparaison avec plusieurs derniers optimiseurs appliqués sur un cas de test pratique. Après avoir exécuté tous les optimiseurs 30 fois indépendamment, la méthode proposée avec une erreur absolue minimale est égale à 3,4831e−4 montre les meilleurs résultats par rapport aux autres. Recientemente, se prestó mucha atención a la aplicación de energías renovables en temas ambientales. Mientras tanto, la industria de pilas de combustible, que se considera una industria respetuosa con el medio ambiente, es uno de los componentes importantes de este proyecto. De hecho, son dispositivos para la conversión directa de energía química en energía eléctrica mediante una reacción electroquímica sin necesidad de piezas mecánicas. En este estudio, se intenta modelar uno de sus tipos importantes, llamado celdas de combustible de membrana de intercambio de protones, para que pueda usarse en la predicción del comportamiento de la celda de combustible y examinar varios parámetros que afectan el rendimiento de la celda. La idea principal es la estimación óptima de los parámetros para las celdas de combustible de membrana de intercambio de protones minimizando el valor total de error al cuadrado entre el voltaje de salida empírico y el voltaje de salida aproximado. Para dar mejores resultados en términos de precisión y confiabilidad, se utiliza un nuevo diseño de una metaheurística llamada Algoritmo equilibrado Water Strider. Los resultados del método sugerido se validan finalmente mediante la comparación con varios de los últimos optimizadores aplicados en un caso de prueba práctico. Después de ejecutar todos los optimizadores 30 veces de forma independiente, el método propuesto con un error absoluto mínimo igual a3.4831e −4 muestra los mejores resultados hacia los demás. Recently, much attention was paid to the application of renewable energy in environmental issues. Meanwhile, the fuel cell industry, which is considered an environmentally friendly industry, is one of the important components of this project. They are in fact devices for the direct conversion of chemical energy into electrical energy by an electrochemical reaction without the need for any mechanical parts. In this study, it is attempted to model one of their important types, called proton exchange membrane fuel cells, so that it can be used in predicting the behavior of the fuel cell and examining various parameters affecting the performance of the cell. The main idea is to optimal parameters estimation for the proton exchange membrane fuel cells by minimizing the total Squared Error value between the empirical output voltage and the approximated output voltage. For giving better results in terms of accuracy and reliability, a new design of a metaheuristic called the balanced Water Strider Algorithm is utilized. The results of the suggested method are finally validated by comparison with several latest optimizers applied on a practical test case. After running all of the optimizers 30 times independently, the proposed method with minimum absolute error equals 3.4831e−4 shows the best results toward the others. في الآونة الأخيرة، تم إيلاء الكثير من الاهتمام لتطبيق الطاقة المتجددة في القضايا البيئية. وفي الوقت نفسه، تعد صناعة خلايا الوقود، التي تعتبر صناعة صديقة للبيئة، أحد المكونات المهمة لهذا المشروع. وهي في الواقع أجهزة للتحويل المباشر للطاقة الكيميائية إلى طاقة كهربائية عن طريق تفاعل كهروكيميائي دون الحاجة إلى أي أجزاء ميكانيكية. في هذه الدراسة، يتم محاولة نمذجة أحد أنواعها المهمة، يسمى خلايا وقود غشاء التبادل البروتوني، بحيث يمكن استخدامه في التنبؤ بسلوك خلية الوقود وفحص المعلمات المختلفة التي تؤثر على أداء الخلية. الفكرة الرئيسية هي تقدير المعلمات الأمثل لخلايا وقود غشاء التبادل البروتوني عن طريق تقليل إجمالي قيمة الخطأ التربيعي بين جهد الخرج التجريبي وجهد الخرج التقريبي. لإعطاء نتائج أفضل من حيث الدقة والموثوقية، يتم استخدام تصميم جديد لميتاهيوريستيك يسمى خوارزمية سترايدر المياه المتوازنة. يتم التحقق من صحة نتائج الطريقة المقترحة أخيرًا بالمقارنة مع العديد من أحدث المحسنات المطبقة على حالة اختبار عملية. بعد تشغيل جميع المحسنات 30 مرة بشكل مستقل، فإن الطريقة المقترحة مع الحد الأدنى من الخطأ المطلق تساوي 3.4831e -4 تظهر أفضل النتائج تجاه الآخرين.