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International Journal of Renewable Energy Development
Number of Followers: 6  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2252-4940 - ISSN (Online) 2252-4940
Published by Diponegoro University Homepage  [18 journals]
  • Economic Feasibility of Solar Irrigation Pumps: A Study of Northern
           Bangladesh

    • Authors: Md. Tawhidul Islam; Md. Elias Hossain
      Abstract: Bangladesh is the most densely populated country in the world. With a total population of around 165 million, the country has constantly been facing food security challenges and other problems. Therefore, increasing food production is one of the feasible solutions to this challenge, and proper agricultural land use for food production bears critical importance. Adopting sustainable irrigation systems and viable technologies would be vital for ensuring efficient use of agricultural land in Bangladesh to safeguard the country's food security. Solar irrigation pumps (SIPs) can be a reliable option in this regard. However, Bangladesh has experienced a prolonged growth rate of SIP installation in the last decade.  The countryhas set a target to install 10000 SIPs by the year 2027, albeit it is a tiny share of the 1.57 million conventional irrigation pumps operating in the country. This study aims to investigate the economic feasibility of the SIPs operating in the northern region of Bangladesh in terms of estimating financial feasibility and environmental benefits. The study is mainly based on primary data collected from the users of SIPs from two Upazilas of Dinajpur and Rangpur districts. A total of 14 SIPs, categorized into large, medium, and small pumps, are selected randomly from the available SIPs in the study areas. The financial analysis reveals that small SIPs are the most profitable option (20% IRR) for investment. Large SIPs are moderately profitable (10% IRR), and their profitability can be improved (10.50% IRR) by introducing additional uses of solar energy. However, medium SIPs are the worst (5% IRR) option for investment. In the study areas, large and medium SIPs are designed for the 'fees for service model', and small SIPs are designed for the 'fees for ownership model'. It is found that the 'fees for ownership model' is more profitable than the 'fees for service model'. Moreover, the net environmental benefit for all SIPs is found almost equal to the given subsidy for installing them. Also, the net environmental benefit per kilowatt peak (kWp) is highest for the small SIPs. This paper recommends that additional use (e.g., husking, grinding, supply excess electricity to grid, and so on) of solar energy can improve the profitability of investmenton SIPs. Further, the government should continue giving grants for installing SIPs and promote 'fees for ownership model' (small SIPs) for personal use. It would speed up the dissemination rate of SIPs and help increase the country's agricultural production and improve the environmental conditions.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Hydrodynamic Model and Tidal Current Energy Potential in Lepar Strait,
           Indonesia

    • Authors: Harman Ajiwibowo; Munawir Bintang Pratama
      Abstract: Previous studies have shown the abundance of tidal energy resources in Indonesia. However, some sites have yet to be considered. The Lepar Strait, for example, is located between Bangka and Lepar Islands. This paper describes a field survey and numerical modelling conducted in the Lepar Strait. The modelling was performed using Delft3D, with the aim of determining potential sites for harvesting tidal current energy and estimate the generated power. In the modelling, the domain decomposition method was employed for model downscaling, allowing grid resolution reaching 130 x 130 m2, which is sufficient to represent the narrow gaps between tiny islands in the area of interest. The National Bathymetric (Batnas) from the Geospatial Information Agency (BIG) and the International Hydrographic Organization (IHO) tide constituents were applied for the bathymetry and tide elevation boundaries. The comparison between the surveyed and modelled data showed a good agreement. The RMSE and r for water level are > 0.95 and < 0.15, and the RMSE for velocity was <0.19. Furthermore, an energetic flow reaching 1.5 m/s was found at the Northern part of Lepar Strait, situated at the narrow gaps. The Gorlov Helical Turbine was selected in this study due to shallow water and low mean velocity. In the 2019 model, the power density and power output at the best potential sites were 2,436.94 kWh/m2 and 1,870.41 kWh, respectively. This number is higher than those previously found in Kelabat Bay. Nonetheless, it is still far below the currently promising project in Larantuka and Lombok Straits. Future research is recommended, to conduct a detailed field measurement campaign and assess the impact of energy extraction in more detail.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Numerical Analysis of Velocity Magnitude on Wave Energy Converter System
           in Perforated Breakwater

    • Authors: Oki Setyandito; Nizam Nizam, Andrew John Pierre, Gede Dharma Suputra, Yureana Wijayanti, Martin Anda
      Abstract: Waves are an alternative energy source that can be used for electricity generation. Wave Energy Converter (WEC) system in perforated breakwater is potentially applicable WEC system for coastal area. The magnitude of wave energy generated is determined by the volume of sea water inside the perforated breakwater. This volumetric flow rate is calculated using the flow velocity at perforated holes on the structure slope. Therefore, this research aims to study the velocity magnitude by analyzing the interrelation among wave steepness, wave run-up and relative velocity. The method used consists of applying numeric 3D flow model in the perforated structure of the breakwater with the variation of wave height, wave period and structure slope. The result shows that, the steeper the structure, the bigger is the relative run up (Ru/H). The higher the relative run up, the higher are the relative run-up velocities (V/Vru). As the velocity increase, the volumetric flow rate inside perforated breakwater will be higher, which leads to higher wave energy. Hence, it can be concluded that the higher the velocities (V/Vru), the higher is the wave energy generated.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Improved Evaluation of The Wind Power Potential of a Large Offshore Wind
           Farm Using Four Analytical Wake Models

    • Authors: Mohammed Amine Hassoine; Fouad Lahlou, Adnane Addaim, Abdessalam Ait Madi
      Abstract: The objective of this paper is to investigate the ability of analytical wake models to estimate the wake effects between wind turbines (WTs). The interaction of multiple wakes reduces the total power output produced by a large offshore wind farm (LOFWF). This power loss is due to the effect of turbine spacing (WTS), if the WTs are too close, the power loss is very significant. Therefore, the optimization of turbine positions within the offshore wind farm requires an understanding of the interaction of wakes inside the wind farm. To better understand the wake effect, the Horns Rev 1 offshore wind farm has been studied with four wake models, Jensen, Larsen, Ishihara, and Frandsen. A comparative study of the wake models has been performed in several situations and configurations, single and multiple wakes are taken into consideration. Results from the Horns Rev1 offshore wind farm case have  been evaluated and compared to observational data, and also  with the previous studies. The power output of a row of WTs is sensitive to the wind direction. For example, if a row of ten turbines is aligned with the 270° wind direction, the full wake condition of WTs is reached and the power deficit limit predicted by Jensen model exceeds 70%. When a wind direction changes only of  10° (260° and 280°), the deficit limit reduces to 30%. The obtained results show that a significant power deficit occurs when the turbines are arranged in an aligned manner. The findings also showed that all four models gave acceptable predictions of the total power output. The comparison between the calculated and reported power output of Horns Revs 1 showed that the differences ranged from - 8.27 MW (12.49%) to 15.27 MW (23.06%) for the Larsen and Frandsen models, respectively.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Comparative Analysis of Hybrid Renewable Energy Systems for Off-Grid
           Applications in Chad

    • Authors: Abdelhamid Issa Hassane; Djamal Hissein Didane, Abakar Mahamat Tahir, Ruben Martin Mouangue, Jean Gaston Tamba, Jean-Marie Hauglustaine
      Abstract: In this study, a techno-economic feasibility analysis of hybrid renewable energy systems for four household categories in rural areas of Chad was studied based on the multi-criteria assessment technique. The problem of this study is to know the best optimal solution in the technical and economic feasibility study of the decentralized mini-grids for the rural electrification of isolated villages in Chad. The main objective of the work is to assess technically, economically and environmentally the feasibility of six scenarios of hybrid systems in five isolated sites in Chad. The performance analysis involved six scenarios of possible hybrid solutions while achieving a supply-demand balance for sustainable electrification of the remote villages, using the HOMER software. The results have shown that the optimum combination of the hybrid system was the photovoltaic/battery system with a Net Present Cost (NPC) of US $ 328,146 and it was found at Etena village. The photovoltaic/Wind/Diesel/Battery hybrid configuration was the least optimum system and it has appeared in Mandelia village. In terms of energy cost, the lowest Levelized Cost of Energy (LCOE) was estimated at US $ 0.236/kWh in a photovoltaic/Wind/Battery configuration at Koundoul site and the highest costs US $ 0.363/kWh in the photovoltaic/Battery configuration at the Linia site. It is established that hybrid solutions can be developed to make electricity available and accessible to the population of the remote rural areas in Chad. However, it is imperative that the local government must subsidize the diesel price to promote the adaptation of the abundant renewable solutions.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • A Comparative Study of Regression Models and Meteorological Parameters to
           Estimate the Global Solar Radiation on a Horizontal Surface for Baghdad
           City, Iraq

    • Authors: Moafaq K.S. Al-Ghezi; Bashar K. Mahmoud, Tamadher M.A Alnasser, Miqdam Tariq Chaichan
      Abstract: In this study, data of the monthly average of daily global solar radiation falling on a horizontal surface, relative humidity, maximum temperature, and duration of sunshine for the city of Baghdad were collected through two sources. First, from the Iraqi Meteorological Authority (IMA) for a period extending from 1961 to 2016. The second is from NASA, for the period from 1984 to 2004. Then, four linear regression models, two single and two polynomials were formulated to calculate the values of the monthly average of daily global horizontal solar radiation (GHSR) incidents. The models calculated the monthly average of daily extraterrestrial radiation and day length, using some data provided by NASA and the IMA. To ensure the validity of the used models, a statistical test was performed for the performance of the proposed models, using the indicators mean bias Error (MBE), root mean square error (RMSE) as well as mean percentage error (MPE). The validation shows the relationship between the measured and computed values (through the analysis of the results), where a great convergence was found between the measured and calculated values. This means that the proposed models can be adapted to predict global solar radiation. The highest values of measured solar radiation were during the month of June, which were 28.555 and 27.280 MJ/m2/day from the IMA and NASA, respectively. The same applies to the radiation calculated using the four empirical models. The month of June was the highest in terms of solar radiation values. The radiation values were 28.947, 26.315, 29.699, and 26.716 MJ/m2/day for the first, second, third, and fourth models, respectively. The lowest values of measured and calculated radiation were during the month of December. Always, radiation measured by the IMA was greater than those of NASA, as well as the values of radiation calculated in the two IMA-based models were greater than the other two NSA-based models. In the absence of a method for measuring the diffuse and direct (beam) solar radiations, as well as the lack of such values by meteorological authorities, and its paramount importance, they were reported to mathematically calculate them in this study. The values of statistical indicators RMSE; MJ/m2/day, MBE; MJ/m2/day and MPE% were (0.4769, 0.0164, 0.2207), (0.8641, 0.1773, -0.9680), (0.6420, 0.3996, -1.1487), (0.9604, 0.218, -1.0225) for the first, second, third and fourth models, respectively. According to the results of the statistical test, it can be indicated that the single linear regression model, based on the IMA’s data (model No.1), is the most accurate to calculate global solar radiation for Baghdad City.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Optimisation and Management of Virtual Power Plants Energy Mix Trading
           Model

    • Authors: Zahid Ullah; Nayyar Hussain Mirjat, Muhammad Baseer
      Abstract: . In this study, a robust optimisation method (ROM) is proposed with aim to achieve optimal scheduling of virtual power plants (VPPs) in the day-ahead electricity markets where electricity prices are highly uncertain. Our VPP is a collection of various distributed energy resources (DERs), flexible loads, and energy storage systems that are coordinated and operated as a single entity. In this study, an offer and bid-based energy trading mechanism is proposed where participating members in the VPP setting can sell or buy to/from the day-ahead electricity market to maximise social welfare (SW). SW is defined as the maximisation of end-users benefits and minimisation of energy costs. The optimisation problem is solved as a mixed-integer linear programming model taking the informed decisions at various levels of uncertainty of the market prices. The benefits of the proposed approach are consistency in solution accuracy and traceability due to less computational burden and this would be beneficial for the VPP operators. The robustness of the proposed mathematical model and method is confirmed in a case study approach using a distribution system with 18-buses. Simulation results illustrate that in the highest robustness scenario, profit is reduced marginally, however, the VPP showed robustness towards the day-ahead market (DAM) price uncertainty
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Effect of Hydrogen Peroxide on Hydrogen Production from Melon Fruit
           (Cucumis melo L.) Waste by Anaerobic Digestion Microbial Community

    • Authors: Agung Dian Kharisma; Yumechris Amekan, Sarto Sarto, Muhammad Nur Cahyanto
      Abstract: Biohydrogen (H2) production has the potential to provide clean, environmentally friendly, and cost-effective energy sources. The effect of increasing oxidative stress on biohydrogen production by acid-treated anaerobic digestion microbial communities was studied. The use of varying amounts of hydrogen peroxide (H2O2; 0.1, 0.2, and 0.4 mM) for enhancing hydrogen production from melon fruit waste was investigated. It was found that H2O2 amendment to the H2-producing mixed culture increased hydrogen production. Treatment with 0.4 mM H2O2 increased cumulative H2 output by 7.7% (954.6 mL/L), whereas treatment with 0.1 mM H2O2 enhanced H2 yield by 23.8% (228.2 mL/gVS) compared to the untreated control. All treatments showed a high H2 production rate when the pH was 4.5 – 7.0.  H2O2-treated samples exhibited greater resilience to pH reduction and maintained their H2 production rate as the system became more acidic during H2 fermentation. The application of H2O2 affected the volatile fatty acid (VFA) profile during biohydrogen fermentation, with an increase in acetic and propionic acid and a reduction in formic acid concentration. The H2O2 treatment positively affects H2 production and is proposed as an alternative way of improving H2 fermentation.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Efficiency Improvement of Ground-Mounted Solar Power Generation in
           Agrivoltaic System by Cultivation of Bok Choy (Brassica rapa subsp.
           chinensis L.) Under the Panels

    • Authors: Manoch Kumpanalaisatit; Worajit Setthapun, Hathaitip Sintuya, Surachai Narrat Jansri
      Abstract: An agrivoltaic system is a combination of solar power generation and crop production that has the potential to increase the value of land. The system was carried out at a 25-kW photovoltaic (PV) power plant located at the Asian Development College for Community Economy and Technology (adiCET), Chiang Mai Rajabhat University, Thailand. The growth and yield of bok choy (Brassica rapa subsp. chinensis L.) and the solar power output were investigated and compared with the control. Moreover, the efficiency of the agrivoltaic system was evaluated. The results indicated that the average intensity of solar radiation of 569 W/m2 was obtained. The highest power generation was recorded in the PV with crop production of 2.28 kW. Furthermore, the control plot of crop production at 35 days provided higher growth than bok choy plots under solar panels of 2.1 cm in plant height, 6 in leaf number, 2.2 cm in leaf length and 0.2 cm in leaf wide. High-yield of bok choy was also obtained in the control plot of 17.31 kg. Although the yield of bok choy is extremely low, possibly because of light intensity, crop cultivation under solar panels could reduce the module temperature to less than the PV control of 0.18 °C, resulting in increased voltage and power generation by around 0.09 %. Therefore, an agrivoltaic system is another option for increasing revenue and land equivalent ratio in solar power plants focusing only on electricity generation. However, suitable crops for the space under PV panels should be investigated further.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Influence of the Random Data Sampling in Estimation of Wind Speed
           Resource: Case Study

    • Authors: Adekunlé Akim Salami; Seydou Ouedraogo, Koffi Mawugno Kodjoa, Ayité Sénah Akoda Ajavona
      Abstract: In this study, statistical analysis is performed in order to characterize wind speeds distribution according to different samples randomly drawn from wind speed data collected. The purpose of this study is to assess how random sampling influences the estimation quality of the shape (k) and scale (c) parameters of a Weibull distribution function. Five stations were chosen in West Africa for the study, namely: Accra Kotoka, Cotonou Cadjehoun, Kano Mallam Aminu, Lomé Tokoin and Ouagadougou airport. We used the energy factor method (EPF) to compute shape and scale parameters. Statistical indicators used to assess estimation accuracy are the root mean square error (RMSE) and relative percentage error (RPE). Study results show that good accuracy in Weibull parameters and power density estimation is obtained with sampled wind speed data of 30% for Accra, 20% for Cotonou, 80% for Kano, 20% for Lomé, and 20% for Ouagadougou site. This study showed that for wind potential assessing at a site, wind speed data random sampling is sufficient to calculate wind power density. This is very useful in wind energy exploitation development.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Impact of Globalization and Renewable Energy Consumption on Environmental
           Degradation: A Lesson for South Africa

    • Authors: Seun Damola Oladipupo; Husam Rjoub, Dervis Kirikkaleli, Tomiwa Sunday Adebayo
      Abstract: South Africa is one of Africa's most polluted countries, with rising CO2 emissions posing a threat. South Africa must discover ways of minimizing pollution and take necessary steps before it is too late in order to achieve sustainable growth. For this purpose, this research assesses the ecological consequences of globalization, nonrenewable energy use, economic growth and renewable energy consumption in South Africa. The study leverages on the non-linearity advantages of the novel quantile on quantile regression (QQR) method for a robust analysis as opposed to the use of conventional linear approaches, thereby overcoming conspicuous shortfalls in extant studies, while offering a detailed explanation of the overall dependency structure between CO2 emissions and globalization, nonrenewable energy use and renewable energy use using a dataset covering the period between 1970 and 2018. The outcomes suggest that nonrenewable energy use, globalization, and economic growth contribute to environmental degradation in the majority of the quantiles, while the effect of renewable energy use on CO2 is not strong at all quantiles. The study highlights that economic expansion, nonrenewable energy use and globalization play key roles in in mitigating environmental sustainability in South Africa, while renewable energy is not sufficient to meet environmental requirements.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Impacts of Solar Electricity Generation on the Thai Electricity Industry

    • Authors: Buncha Wattana; Phinyo Aungyut
      Abstract: This paper analyses the impacts of electricity generation from solar energy on the Thai electricity industry. In this paper, three scenarios (REF, Solar2015 and Solar2018) are developed to represent an increased levels of electricity produced from solar energy. A Low Emissions Analysis Platform (LEAP) model is employed, in this paper, to assess the impacts for the period 2019–2037. This paper assesses and analyses the scenario impacts in terms of diversification of electricity generation, fossil fuel requirement and emissions of CO2 and SO2. The analysis reveals that increased electricity generation from solar energy would help diversify energy supply for electricity generation, reduce fossil fuel imports, and therefore help improve energy security of the country. Furthermore, it would help mitigating CO2 and SO2 emissions – an issue of environmental significance. Despite several benefits, there are a number of emerging barriers for promoting electricity generation from solar energy in Thailand. These include the intermittency of solar energy, high-capital cost, unsupportable grid infrastructure and unfavourable regulatory framework. This paper, therefore, suggests that the implementation of energy storage system, provision of financial incentives to potential investors, improvement of grid flexibility and the revision of the regulations to support solar energy business could be effective strategies in order to address the barriers facing the Thai electricity industry.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Au Nanoparticles Effect on Inverted ZnO Nanorods/Organic Hybrid Solar Cell
           Performance

    • Authors: Pham Hoai Phuong; Kang Jea Lee, Huynh Tran My Hoa, Hoang Hung Nguyen, Quang Trung Tran, Nguyen Thi Hai Yen, Tran Viet Cuong
      Abstract: The sun provides a plentiful and inexpensive source of carbon-neutral energy that has yet to be fully utilized. This is a major driving force behind the development of organic photovoltaic (OPV) materials and devices, which are expected to offer benefits such as low cost, flexibility, and widespread availability. For the photovoltaic performance enhancement of the inverted ZnO-nanorods (NR)/organic hybrid solar cells with poly(3-exylthiophene):(6,6)-phenyl-C61-butyric-acid-methylester (P3HT:PCBM) and poly (3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) active layers, gold nanoparticles (Au-NPs) were introduced into the interface between indium-thin-oxide cathode layer and ZnO cathode buffer layer, and the efficiency improvement was observed. It's worth noting that adding Au NPs had both a positive and negative impact on device performance. Au NPs were shown to be advantageous to localized surface plasmon resonance (LSPs) in the coupling of dispersed light from ZnO NRs in order to extend the light's path length in the absorbing medium. Although the light absorption in the active layer could be enhanced, Au NPs might also act as recombination centers within the active layer. To avoid this adverse effect, Au NPs are covered by the ZnO seeded layer to prevent Au NPs from direct contact with the active layer. The dominant surface plasmonic effect of Au NPs increased the photoelectric conversion efficiency from 2.4% to 3.8%.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • The Effects of Dopant Concentration on the Performances of the
           a-SiOx:H(p)/a-Si:H(i1)/a-Si:H(i2)/µc-Si:H(n) Heterojunction Solar Cell

    • Authors: Dadan Hamdani; Soni Prayogi, Yoyok Cahyono, Gatut Yudoyono, Darminto Darminto
      Abstract: In this work, the imbalances in band gap energy between p-window layer and intrinsic layer (p/i interface) in p-i-n type solar cells to suppress charge recombination adopting with the addition of buffer layer, at p/i interface, namely solar cell structures without buffer (Cell A) and with buffer (Cell B). Using well-practiced AFORS-HET software, performances of Cell A and Cell B structures are evaluated and compared to experimental data. A good agreement between AFORS-HET modelling and experimental data was obtained for Cell A (error = 1.02%) and Cell B (error = 0.07%), respectively. The effects of dopant concentrations of the p-type and n-type were examined with respect to cell B for better performance by analysing the energy band diagram, the electric field distribution, the trapped hole density, the light J-V characteristics, and the external quantum efficiency. The simulated results of an optimised Cell B showed that the highest efficiency of 8.81% (VOC = 1042 mV, JSC = 10.08 mA/cm2, FF = 83.85%) has been obtained for the optimum dopant values of NA = 1.0 x 1019 cm-3 and ND = 1.0 x 1019 cm-3, respectively. A comparison between experimental data and simulation results for Cell B showed that the conversion efficiency can be enhanced from 5.61% to 8.81%, using the optimized values
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Study and Optimization of a Hybrid Power Generation System to Power
           Kalakala, a Remote Locality in Northern Côte d'Ivoire

    • Authors: Jules Yao Koffi; Koita Mohamed Sako, Blaise Kamenan Koua, Paul Magloire Ekoun Koffi, Yao Nguessan, Alphonse Kouadio Diango
      Abstract: This work presents the results of a study to optimize the production of electricity, by hybrid system Photovoltaic – Diesel – Batteries, to power the village of Kalakala in the north of Côte d'Ivoire. The study site is an isolated rural community, powered by a diesel generator. It is located in northern Côte d'Ivoire. HOMER software has been used for system simulation and optimization. The result of this study is then compared to those of PV - Batteries and diesel alone systems. From the results of the simulations, it appears that the optimal combination of the hybrid system includes a diesel generator of 50 kW, a photovoltaic field of 46 kW, 10 batteries of 48V and a converter of 100 kW. With a photovoltaic penetration rate of 52.7%, this system, compared to the photovoltaic - batteries system, reduces the photovoltaic field by 56%, the number of batteries by 61.5% and increases battery life by 42.84%. Compared to diesel alone, it reduces fuel consumption and the quantity of CO2 by 60% and improves diesel efficiency by 17%. The cost of generating electricity for the hybrid system is €0.373/kWh compared to €0.466 and €0.608/kWh respectively, for the PV-Batteries and diesel alone systems. The hybrid system with the best technical, economic and environmental performance could be a good alternative for generating electricity in remote communities.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Thermogravimetric Analysis and Kinetic Study on Catalytic Pyrolysis of
           Rice Husk Pellet using Its Ash as a Low-cost In-situ Catalyst

    • Authors: Wusana Agung Wibowo; Rochim Bakti Cahyono, Rochmadi Rochmadi, Arief Budiman
      Abstract: The thermogravimetric behaviors and the kinetic parameters of uncatalyzed and catalyzed pyrolysis processes of a mixture of powdered raw rice husk (RRH) and its ash (RHA) in the form of pellets were determined by thermogravimetric analysis at three different heating rates, i.e., 5, 10, and 20 K/min, from 303 to 873 K. This research aimed to prove that the rice husk ash has a catalytic effect on rice husk pyrolysis. To investigate the catalytic effect of RHA, rice husk pellets (RHP) with the weight ratio of RRH:ARH of 10:2 were used as the sample. Model-free methods, namely Friedman (FR), Kissinger-Akahira-Sunose (KAS), and Flynn-Wall-Ozawa (FWO), were used to calculate the apparent energy of activation(EA). The thermogravimetric analysis showed that the decomposition of RHP in a nitrogen atmosphere could be divided into three stages: drying stage (303-443 K), the rapid decomposition stage (443-703 K), and the slow decomposition stage (703-873 K). The weight loss percentages of each stage for both uncatalyzed and catalyzed pyrolysis of RHP were 2.4-5.7%, 35.5-59.4%, and 2.9-12.2%, respectively. Using the FR, FWO, and KAS methods, the values of  for the degrees of conversion (a) of 0.1 to 0.65 were in the range of 168-256 kJ/mol for the uncatalyzed pyrolysis and 97-204 kJ/mol for the catalyzed one. We found that the catalyzed pyrolysis led the  to have values lower than those got by the uncatalyzed one. This phenomenon might prove that RHA has a catalytic effect on RHP pyrolysis by lowering the energy of activation.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Waste-Based Second-Generation Bioethanol: A Solution for Future Energy
           Crisis

    • Authors: Yasindra Sandamini Chandrasiri; W. M. Lakshika Iroshani Weerasinghe, D. A. Tharindu Madusanka, Pathmalal M. Manage
      Abstract: The demand for more environmentally friendly alternative renewable fuels is growing as fossil fuel resources are depleting significantly. Consequently, bioethanol has attracted interest as a potentially viable fuel. The key steps in second-generation bioethanol production include pretreatment, saccharification, and fermentation. The present study employed simultaneous saccharification and fermentation (SSF) of cellulose through bacterial pathways to generate second-generation bioethanol utilizing corncobs and paper waste as lignocellulosic biomass. Mechanical and chemical pretreatments were applied to both biomasses. Then, two bacterial strains, Bacillus sp. and Norcadiopsis sp., hydrolysed the pretreated biomass and fermented it along with Achromobacter sp., which was isolated and characterized from a previous study. Bioethanol production followed by 72 h of biomass hydrolysis employing Bacillus sp. and Norcadiopsis sp., and then 72 h of fermentation using Achromobacter sp. Using solid phase micro extraction combined with GCMS the ethanol content was quantified. SSF of alkaline pretreated paper waste hydrolysed by Bacillus sp. following the fermentation by Achromobacter sp. showed the maximum ethanol percentage of 0.734±0.154. Alkaline pretreated corncobs hydrolyzed by Norcadiopsis sp. yielded the lowest ethanol percentage of 0.155±0.154. The results of the study revealed that paper waste is the preferred feedstock for generating second-generation bioethanol. To study the possible use of ethanol-diesel blends as an alternative biofuel E2, E5, E7, and E10 blend emulsions were prepared mixing commercially available diesel with ethanol. The evaluated physico-chemical characteristics of the ethanol-diesel emulsions fulfilled the Ceypetco requirements except for the flashpoint revealing that the lower ethanol-diesel blends are a promising alternative to transport fuels. As a result, the current study suggests that second generation bioethanol could be used as a renewable energy source to help alleviate the energy crisis..
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • A Systematic Review on the Renewable Energy Development, Policies and
           Challenges in Nigeria with an International Perspective and Public
           Opinions

    • Authors: Justin Ugwu; Kenneth Chinonso Odo, Leonard Onyedikachi Oluka, Kehinde Oseni Salami
      Abstract: Due to the threat posed by fossil fuels to human existence; many countries around the world have turned attention to renewable sources for power generation to reduce the emission of greenhouse gases and stop ozone layer depletion. This has increased the exploitation of various renewable energy sources which include: hydro, biomass, solar, geothermal and wind in many developed countries. However, most African countries seem not to have awakened to this new reality. This work presents a comprehensive review of available renewable energy capacity in Nigeria, the level of utilization of renewables in Nigeria in comparison to other countries, comparison of renewable energy scenarios among African countries, factors hindering the development of renewables in Nigeria, the country’s renewable energy policy and ways of improving its status in the country. A lot of peer-reviewed journal articles, and grey literatures were gathered from which the most suitable ones were selected for reviews. In addition, opinions of people across the country and beyond, regarding renewable energy status in Nigeria were sought through a questionnaire. It is found that Nigeria is greatly endowed with different renewable energy sources but the level of utilization has been very low due to a myriad of factors such as non-implementation of renewable energy policies, financial issues, unfavorable government policies and lack of adequate research. It is expected that the findings in this work will awaken policies makers in Nigeria to reshape her renewable energy policies and speed up its implementation as well as guide individuals wishing to invest in the nation’s vast renewable resources.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Machine Learning Models Based on Random Forest Feature Selection and
           Bayesian Optimization for Predicting Daily Global Solar Radiation

    • Authors: Mohamed Chaibi; El Mahjoub Benghoulam, Lhoussaine Tarik, Mohamed Berrada, Abdellah El Hmaidi
      Abstract: Prediction of daily global solar radiation  with simple and highly accurate models would be beneficial for solar energy conversion systems. In this paper, we proposed a hybrid machine learning methodology integrating two feature selection methods and a Bayesian optimization algorithm to predict H in the city of Fez, Morocco. First, we identified the most significant predictors using two Random Forest methods of feature importance: Mean Decrease in Impurity (MDI) and Mean Decrease in Accuracy (MDA). Then, based on the feature selection results, ten models were developed and compared: (1) five standalone machine learning (ML) models including Classification and Regression Trees (CART), Random Forests (RF), Bagged Trees Regression (BTR), Support Vector Regression (SVR), and Multi-Layer Perceptron (MLP); and (2) the same models tuned by the Bayesian optimization (BO) algorithm: CART-BO, RF-BO, BTR-BO, SVR-BO, and MLP-BO. Both MDI and MDA techniques revealed that extraterrestrial solar radiation and sunshine duration fraction were the most influential features. The BO approach improved the predictive accuracy of MLP, CART, SVR, and BTR models and prevented the CART model from overfitting. The best improvements were obtained using the MLP model, where RMSE and MAE were reduced by 17.6% and 17.2%, respectively. Among the studied models, the SVR-BO algorithm provided the best trade-off between prediction accuracy (RMSE=0.4473kWh/m²/day, MAE=0.3381kWh/m²/day, and R²=0.9465), stability (with a 0.0033kWh/m²/day increase in RMSE), and computational cost.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Pyrolytic Oil Yield from Waste Plastic in Quezon City, Philippines:
           Optimization Using Response Surface Methodology

    • Authors: Joselito Abierta Olalo
      Abstract: Plastics play an essential role in packaging materials because of their durability to different environmental conditions. With its importance in the community lies the problem with waste disposal. Plastic is a non-biodegradable material, making it a big problem, especially when thrown in dumpsites. In solving the plastic problem, one efficient way to reduce its volume is through thermal processing such as pyrolysis. This study used the pyrolysis method to recover energy from plastic waste. Liquid oil from plastic was comparable to regular fuel used in powering engines. Before the pyrolysis process, a 3k factorial Box-Behnken Design was used in determining the number of experiments to be used. The output oil yield in each pyrolysis runs was optimized in different parameters, such as temperature, residence time, and particle size using response surface methodology to determine the optimum oil yield.  Between polyethylene (PE), mixed plastic, and polystyrene (PS), PS produced its highest oil yield of 90 %. In comparison, mixed plastic produced only its highest oil yield of 45 % in 500 ºC temperature, 120 min residence time, and 3 cm particle size. The produced quadratic mathematical models in PE, mixed, and PS plastic were significant in which the p-values were less than 0.05. Using mathematical models, the optimum oil yield for PE (467.68 ºC, 120 min residence time, 2 cm particle size), mixed (500 ºC, 120 min residence time, 2.75 cm particle size) and PS plastic (500 ºC, 120 min residence time, 2 cm particle size) were 75.39 %, 46.74 %, and 91.38 %, respectively
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Biomass Feedstocks for Liquid Biofuels Production in Hawaii & Tropical
           Islands: A Review

    • Authors: Muhammad Usman; Shuo Cheng, Jeffrey Scott Cross
      Abstract: Many tropical islands, including Aruba, Seychelles, Mauritius, and Pacific Island countries, are entirely dependent on importing fossil fuels to meet their energy demands. Due to global warming, improving energy use efficiency and developing regionally available renewable energy resources are necessary to reduce carbon emissions. This review analyzed and identified biomass feedstocks to produce liquid biofuels targeting tropical islands, particularly focusing on Hawaii as a case study. Transportation and energy generation sectors consume 25.5% and 11.6%, respectively, of Hawaii's imported fossil fuels. Various nonedible feedstocks with information on their availability, production, and average yields of oils, fiber, sugars, and lipid content for liquid biofuels production are identified to add value to the total energy mix. The available biomass conversion technologies and production costs are summarized. In addition, a section on potentially using sewage sludge to produce biodiesel is also included. Based on a comparative analysis of kamani, croton, pongamia, jatropha, energycane, Leucaena hybrid, gliricidia, and eucalyptus feedstock resources, this study proposes that Hawaii and other similar tropical regions can potentially benefit from growing and producing economical liquid biofuels locally, especially for the transportation and electricity generation sectors
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Water-Energy-Food Nexus Review for Biofuels Assessment

    • Authors: Abass A. Gazal; Napat Jakrawatana, Thapat Silalertruksa, Shabbir H. Gheewala
      Abstract: The appropriate use of limited natural resources for generating basic human needs such as energy, food, and water, is essential to help the society function efficiently. Hence, a new approach called nexus is being considered to resolve the effects of intrinsic trade-offs between the essential needs. A review of different methods and frameworks of the water-energy-food nexus was done in this article to give a detailed repository of information on existing approaches and advocate the development of a more holistic quantitative nexus method. Assessing biofuels under the water-energy-food nexus perspective, this review addresses the sustainability of bioenergy production. The results show the countries that can sustainably produce first-generation biofuels. Only a few methods have varied interdisciplinary procedures to analyse the nexus, and more analytical software and data on resource availability/use are needed to address trade-offs between these interacting resource sectors constituting the nexus. Also, “land” is suggested as an additional sector to consider in future studies using both the nexus index and life cycle assessment methodology. The review reveals that to tackle composite challenges related to resource management, cross-disciplinary methods are essential to integrate environmental, socio-political facets of water, energy, and food; employ collaborative frameworks; and seek the engagement of decision-makers.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • A Review on the Role and Impact of Typical Alcohol Additives in
           Controlling Emissions from Diesel Engines

    • Authors: Minh Quang Chau; Van Vang Le, Tri Hieu Le, Van Tam Bui
      Abstract: Today, most of the essential energy needs of humans and production are met by fossil fuels that are expected to be exhausted in the next century. Furthermore, fossil fuels are not renewable and sensitive to the environment. In particular, there is growing concerned about the negative impact of internal combustion engine emissions on climate change and global environmental pollution. Fuel and alcohol-based additives are being considered as good candidates for sustainable alternative fuels used on compression ignition engines. In this review, the different key production pathways and properties of each of the five alcohol additive candidates were discussed. Besides, their effects on the emission characteristics of diesel engines when alcohol additives are added to diesel fuel are also carefully considered. Five candidates including methanol, ethanol, propanol, butanol, and pentanol have been shown to control pollutants from combustion engines while using alcohol-based additives. This is of great significance in the strategy of coping with the threats of pollution and climate change caused by the operation of transport vehicles
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Laminar Flame Characteristics of 2,5-Dimethylfuran (DMF) Biofuel: A
           Comparative Review with Ethanol and Gasoline

    • Authors: Long Vuong Hoang; Danh Chan Nguyen, Thanh Hai Truong, Huu Cuong Le, Minh Nhat Nguyen
      Abstract: Since the early years of the 21st century, the whole world has faced two very urgent problems: the depletion of fossil energy sources and climate change due to environmental pollution. Among the solutions sought, 2,5-Dimethylfuran (DMF) emerged as a promising solution. DMF is a 2nd generation biofuel capable of mass production from biomass. There have been many studies confirming that DMF is a potential alternative fuel for traditional fuels (gasoline and diesel) in internal combustion engines, contributing to solving the problem of energy security and environmental pollution. However, in order to apply DMF in practice, more comprehensive studies are needed. Not out of the above trend, this paper analyzes and discusses in detail the characteristics of DMF's combustible laminar flame and its instability under different initial conditions. The evaluation results show that the flame characteristics of DMF are similar to those of gasoline, although the burning rate of DMF is much higher than that of gasoline. This shows that DMF can become a potential alternative fuel in internal combustion engines.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • Performance and Emission Characteristics of Diesel Engine Using Ether
           Additives: A Review

    • Authors: Quoc Bao Doan; Xuan Phuong Nguyen, Van Viet Pham, Thi Minh Hao Dong, Minh Tuan Pham, Tan Sang Le
      Abstract: Pressure on alternative fuels and strict environmental regulations are driving a strategic shift in the efficient use of renewable biofuels. One of the promising biofuel candidates recently interested by scholars is a biological or organic additive that is added into diesel or biodiesel fuel to improve engine performance and reduce pollutant emissions. With efforts to improve efficiency and combustion quality in cylinders, combustion characteristics, flame structure and emission formation mechanism in compression ignition (CI) engines using blended fuel with organic additives have been studied on the effect of additive properties on the combustion behaviour. In this review, the physicochemical properties of typical organic additives such as ethers compounds and their effects on engine performance and emission characteristics have been discussed and evaluated based on conclusions of recent relevant literature. The results of the analysis revealed the prospect of using ether additives to improve combustion in cylinders and reduce pollutant emissions from CI engines. Obviously, the presence of higher oxygen content, lower viscosity and density, and higher cetane number resulted in a positive change in the combustion dynamics as well as a chain of mechanisms for the formation of pollutant precursors in the cylinder. Therefore, ether additives have a significant contribution to the sustainable energy strategy of the transportation sector in the next period when internal combustion engines still dominate in the competition for energy system choices equipped on vehicles.
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
  • The Delignification of Plants Residue Substrate and Accelerated Fungal
           Consortium Growth-Saccharification: A Practical Approach

    • Authors: Ahmad Syauqi; Siti Fatimah, Durrotul Choiroh
      Abstract: The environments have created an abundance of residual plants from all life sectors, which is not optimal for bioethanol. Therefore, this research developed microbial technology that yielded sugar and fermentation testing. The research aimed to discover the delignification process and compare the consuming sugar by Saccharomyces cerevisiae between the chemical saccharification and accelerated bio-agent of fungal consortium in the engineered media. The innovation of the bioethanol process was conducted using raw materials from biomass. Based on this study, some preliminary hypotheses were made: (i) arranging fungal substrate which consists of residual sugar, molasses, and enriched residual papaya fruits could provide distinguishable growth of cell mass; (ii) the substrate concentration of 2.5% and 7.5% in the growth medium using enriched residual papaya fruits, respectively, as a medium, could be distinguished using delignification. A benchmark was used to compare the chemical and bio-agent saccharification. The consortium that grew and produced cell mass by times factor in molasses has fulfilled the element needed compared to the natural organic substances from the papaya fruit. The higher concentration of delignification material substrate yielded higher growth-saccharification and the average of 10.45 ± 0.21 % Brix was obtained by the fungal consortium in the broth medium, although the acceleration growth is insignificant. Nonetheless, Saccharomyces cerevisiae had successfully fermented saccharification yield sugar from the delignification of plants residual
      PubDate: Tue, 01 Feb 2022 00:00:00 +000
       
 
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