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International Journal of Renewable Energy Development
Number of Followers: 6  Open Access journalISSN (Print) 2252-4940 - ISSN (Online) 2252-4940 Published by Diponegoro University  [16 journals]
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- Microgrid Hybrid Solar/Wind/Diesel and Battery Energy Storage Power
Generation System: Application to Koh Samui, Southern Thailand
Authors: Rawit Khamharnphol; Ismail Kamdar, Jompob Waewsak, Weerasak Chaichan, Sakrapee Khunpetch, Somphol Chiwamongkhonkarn, Chuleerat Kongruang, Yves Gagnon
Abstract: This paper presents the optimization of a 10 MW solar/wind/diesel power generation system with a battery energy storage system (BESS) for one feeder of the distribution system in Koh Samui, an island in southern Thailand. The main objectives are to maximize the deployment of renewable energy-based power generation and to minimize the levelized cost of energy (LCOE). A hybrid renewable energy-based power generation system, consisting of solar PV, wind turbine generators, diesel generator (DiG), bi-directional grid-tied charging inverter (CONV) and BESS, was simulated using HOMER Pro®. This study accessed the database of the National Aeronautics and Space Administration (NASA) for the Surface meteorology and Solar Energy (SSE) for the global solar radiation and temperature, along with the Modern-Era Retrospective analysis for Research and Applications (MERRA-2) wind database. The simulations show that Scenario 1 (PV/Wind/DiG/BESS/CONV) and Scenario 3 (PV/DiG/BESS/CONV) are the optimal configurations regarding the economic indicators (i.e. minimum net present costs (NPC) of 438 M$ and LCOE of 0.20 $/kWh) and the environmental indicators (i.e. lowest greenhouse gases (GHG) emission avoidances of 6,339 tonnes/year and highest renewable fraction (RF) of 89.4%). Furthermore, the sensitivity analysis illustrates that Scenario 3 offers the optimal system type with the largest annual energy production (AEP). Besides contributing to the body of knowledge of optimization methodologies for microgrid hybrid power systems, the outcome of this work will assist the regional energy practitioners and policy makers regarding optimal configurations of microgrid hybrid systems in the development of a Green Island concept for Koh Samui.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Thermal Characteristics of Coconut Shells as Boiler Fuel
Authors: Muhamad Yulianto; Edy Hartulistiyoso, Leopold Oscar Nelwan, Sri Endah Agustina, Chandra Gupta
Abstract: Agricultural waste products, such as wood, rice husk, corn waste, and coconut shells, are abundantly available and can potentially be used as an energy source, particularly for direct combustion in boilers. Because coconut production increases every year, it would be useful to find an alternative use for coconut shells, which are a type of coconut waste. As coconut shells can be used as fuel in boilers, the aim of this study was to evaluate the thermal characteristics of coconut shells in this regard. This study used experimental results to evaluate the performance of a boiler when coconut shells were used as solid fuel. The variations in feed rate were 5, 7.5, and 10 kg/h, and the water flow rates varied between 1 litre per minute (lpm), 2 lpm, and 3 lpm. Temperature data were collected every second via data acquisition , and the mass flow rate of the flue gas was collected every 5 min using a pitot tube equation. One of the parameters evaluated in determining the success of coconut shells as boiler fuel is the thermal efficiency of the boiler. The results showed that the maximum thermal efficiency reached approximately 62.04%, and the maximum flue gas temperature was approximately 500 ℃ for a biomass mass flow rate of 7.5 kg/h. The maximum water temperature of the boiler was 99 ℃, which was reached at a minimum water flow rate of 1 lpm. The results showed that coconut shells are suitable for use as boiler fuel.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- The Design and Analysis of a Novel Vertical Axis Small Water Turbine
Generator for Installation in Drainage Lines
Authors: Werayoot Lahamornchaiyakul; Nat Kasayapanand
Abstract: The objective of this study was to determine the mechanical power efficiency of a novel vertical-axis small water turbine generator for installation in drainage lines. A 3D model was created to evaluate the performance of each design. The system was designed, analysed, and calculated for the most suitable geometries of the water inlet, drainage lines, main structure, and water turbine wheels using computational fluid dynamics software. The diameter of the water turbine wheel in the numerical model was 48 mm. The control volume technique was used in the numerical simulation method, and the k-epsilon turbulence model was employed to find the computational results. For the Computational Fluid Dynamics (CFD), the appropriate mash element for each model section was generated for numerical simulation, which showed that the torque from the water turbine modelling varied depending on the time domains and was related to speed relative to the developed force. The maximum torque and maximum power that a vertical-axis small water turbine for installation in a drainage line could generate at a maximum flow rate of 0.0030 m3/s were 0.55 N.m and 26.84 watts, respectively. Similarly, calculations with mathematical equations, found that the maximum mechanical power value after calculating the rate of loss within the pipe system was 12.95 watts. The forces generated by the speed and pressure of the fluid can then be applied to the structure of the water turbine wheel. The vertical-axis small water turbine for installation in a drainage line was analysed under its self-weight by applying a gravitational acceleration of 9.81 m/s2 in Solidworks Simulation software version 2022. The numerical simulations that resulted from this research could be used to further develop prototypes for small water turbines generating commercial electricity.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Performance Assessment of Malaysian Fossil Fuel Power Plants: A Data
Envelopment Analysis (DEA) Approach
Authors: Ahmad Shafiq Abdul Rahman; Sharifah Aishah Syed Ali, Mohd Rizal Isa, Fazilatulaili Ali, Diyana Kamaruddin, Muhammad Hakiki Baharuddin
Abstract: This paper investigated the performance of Malaysian power plants from the year 2015 to 2017 using Malmquist Total Factor Productivity (TFP) index, which is based on Data Envelopment Analysis (DEA). This approach offers substantial advantages as compared to other existing methods as it can measure productivity changes over time for a variety of inputs and outputs. Moreover, it comprises two primary components: the technical efficiency change and the technological change indexes that provide clearer insight into the factors that are responsible for shifts in total factor productivity. This study uses a single input, installed generation capacity (MW), and two outputs, average thermal efficiency (%) and average equivalent availability factor (%). These output-input data included ten main power plants: TNB Natural Gas, SESB Natural Gas, SESB Diesel, SEB Natural Gas, SEB Coal, SEB Diesel, IPP Semenanjung Natural Gas, IPP Semenanjung Coal, IPP Sabah Natural Gas, and IPP Sabah Diesel. The results have two significant implications for fossil fuel power plants in Malaysia. First, technological change was the primary factor in boosting the TFP performance of the fossil fuel power plants in Malaysia. Meanwhile, the decline in TFP performance in Malaysian fossil fuel power plants may be attributed, in part, to a lack of innovation in technical components as the results found that the average technical efficiency changes in 2015 – 2016 were at 146% and then dropped significantly to 2% in 2016 – 2017. Second, the average scale efficiency changes rose dramatically from -53% to 3% providing a significant contribution to the improvement of technical efficiency changes. The fossil fuel power plants become efficient as the power plants’ size increases. This indicates that the size of a power plant positively impacts the performance of the TFP.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Techno-Economic Analysis of Co-firing for Pulverized Coal Boilers Power
Plant in Indonesia
Authors: Zainal Arifin; Visang Fardha Sukma Insani, Muhammad Idris, Kartika Raras Hadiyati, Zakie Anugia, Dani Irianto
Abstract: The utilization of co-firing (coal-biomass) in existing coal-fired power plants (CFPPs) is the fastest and most effective way to increase the renewable energy mix, which has been dominated by pulverized coal (PC) boilers, particularly in the Indonesian context. This study aims to investigate the technical and economic aspects of co-firing by conducting a pilot project of three PC boiler plants and capturing several preliminary figures before being implemented for the entire plants in Indonesia. Various measured variables, such as plant efficiency, furnace exit gas temperature (FEGT), fuel characteristic, generating cost (GC), and flue gas emissions, were identified and compared between coal-firing and 5%-biomass co-firing. The result from three different capacities of CFPP shows that co-firing impacts the efficiency of the plant corresponding to biomass heating value linearly and has an insignificant impact on FEGT. Regarding environmental impact, co-firing has a high potential to reduce SO2 and NOx emissions depending on the sulfur and nitrogen content of biomass. SO2 emission decreases by a maximum of 34% and a minimum of 1.88%. While according to economic evaluation, the average electricity GC increases by about 0.25 USD cent/kWh due to biomass price per unit of energy is higher than coal by 0.64×10-3 USD cent/kcal. The accumulation in the one-year operation of 5%-biomass co-firing with a 70% capacity factor produced 285,676 MWh of green energy, equal to 323,749 tCO2e and 143,474 USD of carbon credit. The biomass prices sensitivity analysis found that the fuel price per unit of energy between biomass and coal was the significant parameter to the GC changes.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Utilization of Cassava Peel (Manihot utilissima) Waste as an Adhesive in
the Manufacture of Coconut Shell (Cocos nucifera) Charcoal Briquettes
Authors: Bayu Rudiyanto; Intan Rida Agustina, Zeni Ulma, Dafit Ari Prasetyo, Miftah Hijriawan, Bambang Piluharto, Totok Prasetyo
Abstract: Coconut shells and waste cassava peels could be used as the main raw material for biomass briquettes for alternative energy sources in Indonesia. This study aims to analyze the quality of briquettes based on a coconut shell and cassava peel adhesive through proximate analysis with three treatment ratio variations. The ratio of coconut shell to cassava peel used varied from V1 (75%:25%), V2 (70%:30%), and V3 (65%:35%). Based on the result, the charcoal briquettes produced have a density of 0.61 gram/cm³-0.66 gram/cm³, water content of 5.51%-7.85%, ash content of 1.50%-2.86%, combustion rate of 0.021 gram/s-0.026 gram/s, and the calorific value of 6,161 cal/gram-6,266 cal/gram. However, all the treatment variations appropriate the SNI 01-6235-2000, the national standard of Indonesia for the quality of charcoal briquette, which includes the calorific value (>5,000 cal/gram), moisture content (<8%), and ash content (<8%). Briquettes with the best quality were generated by V1 with a density of 0.66 gram/cm³, water content of 5.51%, ash content of 1.50%, combustion rate of 0.026 gram/s, and calorific value of 6,266 cal/gram. Furthermore, briquette material from the coconut shell waste with natural cassava peel adhesive can be feasible as an alternative fuel.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Design and Optimization of a Rack and Pinion Type WEC Using an Auxiliary
Vibrating System
Authors: Avikash Kaushik Chand; Farid Mahboubi Nasrekani, Kabir Mamun, Sumesh Narayan
Abstract: Research on wave energy converters with Rack and pinion type Power Take-Off (PTO) has been increasing over the last few years. A few control methods are used to optimize the performance of the said Wave Energy Converters (WECs). This paper presents a novel auxiliary vibrating system that can be implemented to improve the power input to a wave energy converter with a rack and pinion type PTO in regular waves. The design of the WEC system includes a floater, a double rack and pinion arrangement, a vibrating system, and a Mechanical Motion Rectifier (MMR) consisting of two one-way bearings that can convert the bidirectional wave motion to a unidirectional rotation of the output shaft. Once the waves move the floater upwards, this compresses the vibrating system which absorbs some of the energy and then the vibrating system helps the floater return to its original position by releasing the stored energy. The vibrating system also serves as a control method for limiting rack movement, so the impact of the waves is not detrimental to the system. This article aims to approximate the optimized power input to the system and investigate whether the implementation of a novel vibrating system improves the system power input. Allowing the WEC’s natural frequency to reach the wave’s natural frequency is important as it allows for maximum power absorption. The use of vibration systems to tune the WEC’s natural frequency close to the waves’ is novel and serves as the main factor in choosing this research. The WEC was modeled as 2 spring mass damper systems. Then the characteristic equations of the systems were extracted from the equations of motion and solved analytically to obtain the responses. One-factor-at-a-time (OFAT) method together with two different algorithms (Genetic and Multi-Start algorithms) from MATLAB code were used to optimize the response. The optimized power input to the system was then approximated. For system one, the maximum amplitude of the response was seen at a system mass of 500 kg and stiffness in the range of 100<k<240 N/m. The same was achieved for system two at a system mass of 500 kg and stiffness in the range of 100<k<138. The effect of the stiffness and mass on the response and input power has also been discussed.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Wind Speed Prediction Based on Statistical and Deep Learning Models
Authors: Ilham Tyass; Tajeddine Khalili, Mohamed Rafik, Bellat Abdelouahed, Abdelhadi Raihani, Khalifa Mansouri
Abstract: Wind is a dominant source of renewable energy with a high sustainability potential. However, the intermittence and unstable nature of wind source affect the efficiency and reliability of wind energy conversion systems. The prediction of the available wind potential is also heavily flawed by its unstable nature. Thus, evaluating the wind energy trough wind speed prevision, is crucial for adapting energy production to load shifting and user demand rates. This work aims to forecast the wind speed using the statistical Seasonal Auto-Regressive Integrated Moving Average (SARIMA) model and the Deep Neural Network model of Long Short-Term Memory (LSTM). In order to shed light on these methods, a comparative analysis is conducted to select the most appropriate model for wind speed prediction. The errors metrics, mean square error (MSE), root mean square error (RMSE), mean absolute error (MAE), and mean absolute percentage error (MAPE) are used to evaluate the effectiveness of each model and are used to select the best prediction model. Overall, the obtained results showed that LSTM model, compared to SARIMA, has shown leading performance with an average of absolute percentage error (MAPE) of 14.05%.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Biodiesel Production from a Naturally Grown Green Algae Spirogyra Using
Heterogeneous Catalyst: An Approach to RSM Optimization Technique
Authors: Teku Kalyani; Lankapalli Sathya Vara Prasad, Aditya Kolakoti
Abstract: The present study focuses on oil extraction and biodiesel production from naturally grown green Spirogyra algae. Solvent oil extraction and oil expeller techniques were used to extract the Spirogyra algae oil (SALO), and the oil yields were compared to identify the most productive method. Using chicken eggshell waste (CESW) heterogeneous catalyst (HC) was prepared for the production of Spirogyra algae oil biodiesel (SALOBD). Furthermore, Box–Behnken (BB) assisted response surface method (RSM), an optimisation technique, was used in this study to achieve maximum algae biodiesel yield. From the 29 experimental trails, 96.18 % SALOBD was achieved at molar ratio (10:1), heterogeneous catalyst (0.6 wt.%), temperature (48 oC), and time (180 minutes). The predicted values of R2 (97.51%) and Adj. R2 (95.02 %) is found to be encouraging and fits well with the experimental values. The output results show that HC was identified as the significant process constraint followed by the time. The fatty acid composition (FAC) analysis by Gas Chromatography (GCMS) reveals the presence of 29.3 % unsaturated composition and 68.39 wt. % of the saturated composition. Finally, the important fuel properties of SALOBD were identified in accordance with ASTM D6751. The results obtained using chicken eggshell waste (CESW) for the production of biodiesel were recommended as a diesel fuel replacement to resist energy and environmental calamities.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Theoretical and Experimental Study on the Performance of Photovoltaic
using Porous Media Cooling under Indoor Condition
Authors: Ismail Masalha; Siti Ujila binti Masuri, Omar Badran, Mohd Khairol Anuar bin Mohd Ariffin, Abd Rahim Abi Talib, Fadi Alfaqs
Abstract: This paper presents the theoretical and experimental investigation on performance of a photovoltaic (PV) panel cooled by porous media under indoor condition. Porous media offer a large exterior surface area and a high fluid permeability, making them ideal for PV cells cooling. The photovoltaic panel was cooled using 5 cm thick cooling channel filled with porous media (gravel). Several sizes of porosity (0.35, 0.4, 0.48, and 0.5) at different volume flow rates (1, 1.5, 2, 3, and 4 L/min) were tested to obtain the best cooling process. The theoretical analysis was performed at the optimum case found experimentally, which has a porosity of 0.35 and a volume flow rate of 2 L/min, to test various experimental results of the PV hot surface temperature, related power output, efficiency and I-V characteristic curve. The enhancement obtained in PV power output and efficiency is compared against the case without cooling and the case using water alone without porous media. Results showed that cooling using small size porous media and moderate flow rate is more efficient which reduces the average PV hot surface temperature of about 55.87% and increases the efficiency by 2.13% than uncooled PV. The optimum case reduced the PV hot surface temperature to 38.7°C, and increased the power output to 19 W, efficiency to 6.26%, and the open voltage to 22.77 V. The results showed that the presence of small porous media of 0.35 in the PV cooling process displayed the maximum effectiveness compared to the other two scenarios, because the heat loss from PV surface through porous media layer have developed a homogenous heat diffusion removed much quicker at high flow rate (2 L/min). A good agreement was obtained between experimental and theoretical results for different cases with a standard deviation from 3.2% to 5.6%.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Domestic Wind Energy Planning for Deprived Communities in the Tropics: A
Case Study of Nigeria
Authors: Moses Eterigho Emetere; Omoremime Elizabeth Dania, Sunday Adeniran Afolalu
Abstract: Despite the notable inventions in solar energy, it is still too high for standalone users from developing countries. For example, it cost $2200 to provide power for a two-bedroom apartment while the average citizen lives below the country’s poverty line of $381.75 per year. The use of fossil fuel generators remains cheaper, except there is an affordable energy option for the average populace. The objective of this study is to investigate the wind energy potential for domestic or standalone use in Nigeria. It is proposed that the domestic wind turbine will be relatively cheap for adoption. Hence, there is the need to wholistic examine the prospects of wind energy generation in Nigeria. Though previous studies had been carried out, none has been wholistic as presented in this research work. Forty years wind speed and wind direction dataset, i.e., 1980-2020, was obtained from the Modern-Era Retrospective analysis for Research and Applications (MERRA). The analysis of the wind energy potential across the research locations was considered using five sampling techniques, i.e., considering the general statistics of the forty years dataset; considering ten years in an evenly distributed pattern and accruable wind energy across the nation. It was observed that the early wet season (MAM) is the most unstable among the seasons. Also, sudden multi-directionality of the wind vectorization within forty years was observed. This event is ascribed to evidence of climate change to wind energy generation. Wind energy generation prospect was seen to be generally sustainable and reliable with SON, MAM, DJF and JJA having energy distribution of 325-950 kWh, 539-1700 kWh, 161-650 kWh and 761-3650 kWh respectively. Despite the variation of energy generation over the years within all seasons over Nigeria, it was found that it is predictable and can be optimized using various technological solutions.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Comparison of the Grid and Off-Grid Hybrid Power Systems for Application
in University Buildings in Nigeria
Authors: Chidiebere Diyoke; Marcel Onyekachi Egwuagu, Thomas Okechukwu Onah, Kenneth Chikwado Ugwu, Eberechukwu Chukwunyelum Dim
Abstract: The Nigerian Universities rely on weak and unreliable fossil-based electric grids with diesel engine generators (DEG) as a backup. However, there is a potential to light up the campuses using power systems derived from primary renewable power systems (RPS) like wind turbine (WT) and solar photovoltaic (PV), that can be on or off-grid to improve the energy mix and duration reliably. This study presents the comparative analysis of the optimal hybrid grid and off-grid systems (OGS & OOGS) for serving the demand load of university buildings in four climatic regions of Nigeria. HOMER Pro is used to design and select the systems based on minimal net present cost (NPC) and cost of electricity (COE). The impact of a minimal renewable fraction of 95% on the optimal system architecture (OSA) and COE is studied for both grid and off-grid modes. Also, sensitivity analysis of the impact of key variables on performance for the sites is carried out. It is found that the OGS in the four regions is PV/Converter (Conv), while for the OOGS, it is PV/WT/DEG/battery (BB)/Conv except in Port Harcourt (PH), where it is PV/DEG/BB/Conv. The COE for the OGS in the Savana and monsoon climes of Enugu and PH are 10 and 19% more than that in the warm-semi arid climate zones of Maiduguri and Kano, which is approximately 0.09 $/kWh. The COE ($/kWh) for the OOGS is 0.21 in Maiduguri, 0.245 in Kano, 0.275 in Enugu and 0.338 in PH. An obligatory 95% RF changes the architecture and increases COE in all the locations except Maiduguri, with a slightly improved COE but higher NPC like other locations. It is established that the suggested hybrid system is beneficial and feasible for supplying more reliable and clean energy to educational buildings in different Nigerian locations.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Design of Optical Collimator System for Vehicle Speed Gun using
Non-Imaging Optics
Authors: Le Minh Nhut; Thanh Tuan Pham, Tien Dung Tran, Vu Dinh Huan, Seoyong Shin
Abstract: Vehicle speed guns are usually used in normal sunlight conditions (daytime). If we want to use vehicle speed guns in low light conditions (nighttime), the illuminator is needed to provide sufficient light for the vehicle speed gun to take photos. The illuminator must fulfill two requirements: (i) using the infrared wavelength to ensure that the driver is not startled by dazzling eyes by the illuminator of the proposed speed gun system and (ii) high energy efficiency to make the illuminator compact leading to the use a small battery system to improve the portable of the proposed vehicle speed gun. In this study, an illuminator using a collimator system designed by using non-imaging optics is introduced. LEDs with infrared wavelength are chosen from the library of LightToolsTM, the structure of collimated is designed to transfer the illumination from the LEDs array to a square area of 3x3 m2 to cover the vehicle to detect the vehicle number plate. The design process is built based on the conservation of optical path length in the Matlab program. After that, the designed collimator is simulated in LightToolsTM software. The promising results of the simulation in LightToolsTM show that the collimator can efficiently transfer light from the LED array to the target area with a uniformity of about 70 % and optical efficiency of about 80 %.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- QPVA-Based Electrospun Anion Exchange Membrane for Fuel Cells
Authors: Asep Muhamad Samsudin; Viktor Hacker
Abstract: The anion exchange membrane is one of the core components that play a crucial and inseparable role in alkaline anion exchange membrane fuel cells. Anion exchange membranes (AEMs) were prepared from quaternary ammonium poly(vinyl alcohol) (QPVA) by an electrospinning method. QPVA was used both as material for electrospun fiber mats and as filler for the inter-fiber void matrix. The objective of this work is to investigate the influence of the inter-fibers void matrix filler concentration on the properties and performance of eQPVA-x AEMs. FTIR spectra were used to identify the chemical structures of the AEMs. The primary functional groups of PVA and quaternary ammonium-based ion conducting cation were detected. The surface morphology of QPVA nanofiber mats and eQPVA-x AEMs was observed using SEM. Electrospun nanofiber structures of QPVA with an average size of 100.96 nm were observed in SEM pictures. The ion exchange capacity, swelling properties, water uptake, and OH-ions conductivity were determined to evaluate the performance of eQPVA-x AEMs. By incorporating the QPVA matrix of 5 wt.% concentration, the eQPVA-5.0 AEMs attained the highest ion exchange capacity, water uptake, swelling properties, and OH− conductivity of 0.82 mmol g−1, 25.5%, 19.9%, and 2.26 m×s cm−1, respectively. Electrospun QPVA AEMs have the potential to accelerate the development of alkaline anion exchange membrane fuel cells.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Synthesis and Characterization of Physically Mixed V2O5.CaO as
Bifunctional Catalyst for Methyl Ester Production from Waste Cooking Oil
Authors: Mulyatun Mulyatun; Istadi Istadi, Widayat Widayat
Abstract: Synthesis of the solid bifunctional vanadium-calcium mixed oxides catalyst was accomplished by application of a simple physical mixing approach. In this work, we compared the catalytic activity of CaO and 2%V2O5.CaO catalyst. Various characterization methods, such as X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared (FTIR), BET surface area, and temperature-programmed desorption (TPD) of CO2 and NH3, were involved in studying the newly synthesized catalysts. The presence of CaO, CaCO3, and Ca(OH)2 compounds in the synthesized catalyst were detected by XRD and FTIR analysis. The existence of 2% V2O5 on the CaO catalyst surface was demonstrated by XRF analysis. From TPD-NH3, TPD-CO2, and BET surface area analysis, it was known that the 2% V2O5-CaO catalyst had a higher total number of acid-base sites and surface area than the CaO catalyst. In the fatty acid methyl esters (FAME) production from waste cooking oil (WCO) with higher free fatty acid (FFA), CaO could only catalyze the transesterification reaction. In contrast, 2%V2O5-CaO could successfully catalyze both the esterification of FFA and the transesterification of triglyceride (TG) simultaneously in a one-step reaction process. Thus, these results prove that 2%V2O5.CaO can act as a bifunctional catalyst in the production of biodiesel from WCO. Moreover, the synthesized 2%V2O5.CaO catalyst could achieve a maximum FAME yield of 51.30% under mild reaction conditions, including a 20:1 methanol to oil molar ratio, 60 °C reaction temperature, 1 wt% of catalyst loading, and 3 hours of reaction time.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Preliminary Observation of Biogas Production from a Mixture of Cattle
Manure and Bagasse Residue in Different Composition Variations
Authors: H Hadiyanto; Figa Muhammad Octafalahanda, Jihan Nabila, Andono Kusuma Jati, Marcelinus Christwardana, Kusmiyati Kusmiyati, Adian Khoironi
Abstract: The need of renewable energy is paramount important as it is expected to replace fossil energy. One of renewable energy commonly used for rural area is biomass-based energy. Biogas is a biomass-based energy where organic materials are converted to methane gas via anaerobic digestion process. The limitations of mono-feedstock biogas are instability digestion process, low yield biogas produced and require readjusting C/N ratio, therefore co-digestion process was proposed to overcome these problems. This study aims to investigate the feasibility of anaerobic co-digestion of a mixture of cattle manure and bagasse residue in different weight ratio combinations. Biogas was generated by anaerobic digestion using a mixed substrate composed of a combination of weight ratios of bagasse:cattle manure (1:5, 1:2, 1:1, and 3:1). The kinetic analysis was evaluated by fitting Gompertz and Logistic model to experimental data of cumulative biogas. The result showed that the combination of 1:5 ratio of bagasse waste to cattle manure obtained the best biogas yield with cumulative biogas at 31,000 mL. The kinetic model of Gompertz and Logistic were able to predict the maximum cumulative biogas at ratio of 1:5 (cattle: bagasse) at 31,157.66 mL and 30,112.12 mL, respectively. The other predictions of kinetic parameters were maximum biogas production rate (Rm)= 1,720.45 mL/day and 1,652.31 mL/day for Gompertz and Logistic model, respectively. Lag periods were obtained at 2.403 day and 2.612 day for Gompertz and Logistic model, respectively. The potential power generation of 338.71 Watt has been estimated from biogas. This research has proven a positive feasibility of co-digestion of two feed-stocks (cattle manure and bagasse) for biogas production.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Techno-Economic and Environmental Feasibility Study of a Hybrid
Photovoltaic Electrification System in Back-up Mode : A Case Report
Authors: Henri Wilfried Hounkpatin; Hagninou Elagnon Venance Donnou, Victorin Kouamy Chegnimonhan, Latifath Inoussa, Basile Bruno Kounouhewa
Abstract: In developing countries, institutions that have to operate continuously during daylight hours consume relatively large amounts of electrical energy for lighting and air conditioning, leading to high bills. Untimely power cuts lead to a fluctuation in the voltage delivered by the conventional network, which induces the malfunctioning of electrical equipment and the discontinuity of judicial work. The use of photovoltaic solar energy makes it possible, on the one hand, to ensure continuity of service in the event of damage, and on the other hand to stem greenhouse gas emissions through the sustainable nature of this energy. Solar installations also make it possible to maintain the permanent power supply in the event of instability of the electrical network and to correct the voltage variations undergone by the energy equipment. Thus, this (case) study is based on the energy balances evaluated on the buildings of the jurisdiction of the city of Kandi (Benin) to propose effective solutions of electrification according to six (6) technical scenarii. Each component of the back up system has been sized considering technical requirements and an economic and environmental study has been carried out. The results indicate that the integrated scenario 6 of a "back-up" system with a solar fraction of up to 37% (49.5 kWc) seems to be the most suitable conf iguration for the current needs of the Kandi jurisdiction due to the shortest time to return on investment (5.1 years) and the maximum annual savings generated (33,674 USD). The environmental impact study has made it possible to determine the CO2 emissions avoided as well as the contribution of Carbon credits that this jurisdiction would reap has been evaluated at 115.8 tCO2 equivalent, or 10.6 hectares of forest carbon preserved over the life of the project. This configuration is therefore strongly recommended for a sustainable energy mix in the jurisdictions of Benin as well as for administrative or similar sites where electricity consumption is maximum during the day.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Design and Testing of 3D-Printed Stackable Plant-Microbial Fuel Cells for
Field Applications
Authors: Glenn Paula P Constantino; Justine Mae C. Dolot, Kristopher Ray Simbulan Pamintuan
Abstract: The prevalence of non-renewable energy has always been a problem for the environment that needs a long-term solution. Plant-Microbial Fuel Cells (PMFCs) are promising bioelectrochemical systems that can utilize plant rhizodeposition to generate clean electricity on-site, without harming the plants, paving the way for simultaneous agriculture and power generation. However, one of the biggest hurdles in large-scale PMFC application is the diffused nature of power generation without a clear path to consolidate or amplify the small power of individual cells. In this study, stacking configurations of 3D-printed PMFCs are investigated to determine the amplification potential of bioelectricity. The PMFCs designed in this study are made of 3D-printed electrodes, printed from 1.75 mm Proto-pasta (ProtoPlant, USA) conductive PLA filament, and a terracotta membrane acting as the separator. Six cells were constructed with the electrodes designed to tightly fit with the ceramic separator when assembled. An agriculturally important plant (S. Melongena) was utilized as the model plant for testing purposes. Stacking of cells in series had resulted in severe voltage loss while stacking of cells in parallel preserved the voltage and current of the cells. Cumulative stacking verified the increasing voltage losses as more cells are connected in series, while voltage and current were generally supported well as more cells were connected in parallel. Combination stacks were also investigated, but while 2 sets of 3 cells in parallel stacked in series generated proportionately larger power and power density compared to individual cells, the drop in current density suggests that pure parallel stacks are still more attractive for scaling up, at least for the proposed stake design in this study. The results of this study indicated that the scale up of PMFC technology is possible in field applications to continuously generate electricity while growing edible plants.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Sustainable Long-Term Energy Supply and Demand: The Gradual Transition to
a New and Renewable Energy System in Indonesia by 2050
Authors: Yudiartono Yudiartono; Jaka Windarta, Adiarso Adiarso
Abstract: The objective of this work is to evaluate long-term energy demand and supply decarbonization in Indonesia. On the demand side, electric vehicles and biofuels for transportation and induction stoves and urban gas networks for households were considered. Based on the National Energy Policy, primary energy supply projections optimized NRE power plant use and increase NRE's position in the national energy mix. A Low Emissions Analysis Platform (LEAP) model evaluates 2020–2050 energy demand predictions and low-carbon energy systems. This study's sustainable transition options require two basic technical advances. First, electric vehicles and induction stoves would reduce oil fuel usage by 228.34 million BOE and LPG consumption by 24.65 million BOE. Second, power generation should be decarbonized using NRE sources such as solar, hydro, biomass, geothermal, and nuclear. In 2050, solar power (40 GW), hydropower (38.47 GW), geothermal power (10 GW), and other NRE (24.45 GW, 18.67 GW of which would be biomass power) would dominate NRE electrical capacity. Biomass co-firing for coal power plants would reach 36.35 million tons in 2050. In 2035, the Java-Bali or West Kalimantan system will deploy 1 GW of nuclear power reactors, rising to 4 GW by 2050. Under the Transition Energy (TE) scenario, by 2025 and 2050, new and renewable energy would make up 23% and 31% of the primary energy mix, respectively, reducing GHG emissions per capita. According to predictions, annual GHG emissions per capita will decline from the BAU scenario's 4.48 tonne CO2eq/capita in 2050 to the TE scenario's 4.1 tonne.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
- Modelling the Optimal Electricity Mix for Togo by 2050 Using OSeMOSYS
Authors: Esso-Wazam Honoré Tchandao; Akim Adekunlé Salami, Koffi Mawugno Kodjo, Amy Nabiliou, Seydou Ouedraogo
Abstract: This work uses bottom-up modeling to explore the future evolution trajectories of the electricity mix in Togo by 2050. The objective is to investigate the evolution of the mix and the future investments needed to achieve the sustainable energy and climate change goals. Three scenarios were developed using OSeMOSYS. The reference scenario, named Business As Usual, closely reflects the evolution of the Togolese electricity sector under a business-as-usual assumption and planned capacity increases up to 2030. The second scenario, Net Zero by 2050, is based on the first scenario while ensuring that CO2 emissions cancel out in 2050 by following the Weibull law. The third scenario called Emission Penalty aims not only at the integration of renewable energies like the second one but also at the least cost electricity mix if emission penalties are applied. The results of the cost optimization indicate that photovoltaic and importation are the optimal choices ahead of gas and hydropower. The renewable energy aspect of the electricity mix is more highlighted in the last scenario. At the same time, the model shows that greater energy independence is achievable at the cost of a transitory increase in the cost of the electricity system. A tenfold investment effort is needed in 2030 to ensure either continuity of the status quo or a shift in strategy.
PubDate: Wed, 15 Mar 2023 00:00:00 +000
