Renewable Energy Resources and Technologies
Thenmozhia Pitchai; Rekha Babu; Saravanathamizhan Ramanujam; Iyappan Kuttalam
Abstract
Agricultural residues are potential renewable biomass sources for bio-energy production. The objective of the work is to determine the pyrolysis kinetic parameters of corn cob biomass. Three different heating rates of 10, 20, and 30 °C/min were taken into account in the thermogravimetric analysis. ...
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Agricultural residues are potential renewable biomass sources for bio-energy production. The objective of the work is to determine the pyrolysis kinetic parameters of corn cob biomass. Three different heating rates of 10, 20, and 30 °C/min were taken into account in the thermogravimetric analysis. The Kissinger, Flynn Wall Ozawa (FWO), and Kissinger Akahira Sunose (KAS) model-free methods were employed to calculate the kinetic parameters by the use of the data obtained from TGA. The thermal decomposition process shows three basic phases of pyrolysis: removal of moisture content, primary and secondary pyrolysis. The experimental values were compared with the obtained values from FWO and KAS models; implying that the model values were in good agreement with experimental results. The values of kinetic parameters obtained from Kissinger, FWO, and KAS methods are very similar to their average values of 115, 136, and 131 kJmol-1, respectively. Gas Chromatograph-Mass Spectroscopy (GC-MS) analysis of pyrolysis products is obtained, showing that bio-char and bio-oil contain 10 and 15 different compounds, respectively.
Renewable Energy Resources and Technologies
Tazkieh Gilvari; Behzad Aghabarari; Mohammad Pazouki
Abstract
This study investigated the esterification reaction of different carboxylic acids (Acetic acid, Palmitic acid, and Oleic acid) and ethanol by ZnO, Al2O3-ZnOmixed oxide, and phosphotungestic acid (10 wt %) immobilized on the Al2O3-ZnOmixed oxide. The heterogeneous catalysts were characterized by XRD, ...
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This study investigated the esterification reaction of different carboxylic acids (Acetic acid, Palmitic acid, and Oleic acid) and ethanol by ZnO, Al2O3-ZnOmixed oxide, and phosphotungestic acid (10 wt %) immobilized on the Al2O3-ZnOmixed oxide. The heterogeneous catalysts were characterized by XRD, BET, FE-SEM, and EDX techniques. Optimum yield was achieved by using 10 % HPW/Al2O3-ZnOas the best catalyst, and the effects of the amount of catalyst, molar ratio of acid to alcohol, reaction temperature, and time were investigated to ensure the ideal yield of esterification reaction of acetic acid and ethanol. The results showed that the esterification of acetic acid to its ethyl ester was carried out in 3.5 hours, with an alcohol-to-acid-molar ratio of 2 and a temperature of 80 ˚C with yield 98 %. Moreover, the 10 % HPW/Al2O3-ZnOcatalystshowed well activity in biodiesel production by the esterification of palmitic and oleic acids and the reaction yield did not decrease with an increase in alkyl chain lengthin acid molecules, remarkably.
Renewable Energy Resources and Technologies
Amin Habibzadeh; Samad Jafarmadar
Abstract
A considerable amount of waste heat is produced by internal combustion engines. Bottoming cycle application of Organic Rankine Cycles (ORC) is one of the promising technologies that recuperates the waste heat of engines. A lot of engine waste heat is released into the environment. There are a lot of ...
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A considerable amount of waste heat is produced by internal combustion engines. Bottoming cycle application of Organic Rankine Cycles (ORC) is one of the promising technologies that recuperates the waste heat of engines. A lot of engine waste heat is released into the environment. There are a lot of working fluids that can be applied in these cycles. As the engine waste heat temperature is extremely high, finding a suitable working fluid, which operates properly in the combined cycle, is challenging. In this paper, the thermodynamic analysis of ten working fluids including cyclohexane, HFE7000, HFE7100, n-hexane, n-pentane, R11, R123, R134a, R141b, and R245fa is conducted to observe the influence of different parameters on the system performance and introduce the most appropriate working fluid. Results indicated that, in the studied ranges, R134a had the best performances since (a) its thermal and exergy efficiencies were 17.39 % and 17.34 %, respectively; (b) the thermal efficiency of the engine increased by 9 %, and the net power of the system reached 7.5 kW. Furthermore, there was about 9 % reduction in fuel consumption. On the other hand, among the studied working fluids, cyclohexane operates as the least suitable one by possessing the minimum amounts.
Renewable Energy Resources and Technologies
Bahman Heydari; Shahin Rafiee; Elham Abdollahzadeh Sharghi; Seyed Saeid Mohtasebi
Abstract
The aromatic and dark-colored spearmint essential oil wastewater (SEOW) generally contains a large amount of organic matter, including chemical oxygen demand (COD), phenolic compounds, and inorganic contents. In this study, the pollutant removal performance and biogas production rate of an up-flow anaerobic ...
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The aromatic and dark-colored spearmint essential oil wastewater (SEOW) generally contains a large amount of organic matter, including chemical oxygen demand (COD), phenolic compounds, and inorganic contents. In this study, the pollutant removal performance and biogas production rate of an up-flow anaerobic sludge blanket (UASB) reactor used for the treatment of SEOW were investigated. During the 102 days UASB operation at hydraulic retention time of 60 hours, the organic loading rate (OLR) was increased from 0.14 to 2.69 kg COD/m3.d by increasing the influent SEOW concentration. With increasing OLR from 0.14 to 2.69 kg COD/m3.d, the concentrations of COD and phenol in the influent of the UASB reactor increased to 6720±383 mg/L and 383±88 mg/L, respectively. At OLR equal to 2.69 kg COD/m3.d, the steady-state average removal efficiencies of COD and phenol were 72.0±1.4 and 63.1±6.7 %, respectively. The stability of the anaerobic system was confirmed by the average steady-state ratios of the volatile fatty acid/alkalinity and pH in the UASB reactor, which were less than 0.4 and 7.5±0.1, respectively, at different OLRs. The optimum OLR was found to be 2.69 kg COD/m3.d, where 26.9±1.7 L/d production of biogas containing 63.0±5.2 % and 22.4±4.2 % methane and carbon dioxide, respectively, was obtained. Moreover, at OLR equal to 2.69 kg COD/m3.d, the biogas yield and net heating value were 462.2±46.9 L/kg CODremoved and 24.7±5.2 MJ/m3, respectively. The results of the current study reveal the substantial potential of the UASB reactor in terms of pollutant removal performance and biogas production for the treatment of SEOW.
Renewable Energy Resources and Technologies
Ashkan Gholami; Aryan Tajik; Shahab Eslami; Majid Zandi
Abstract
The current study investigated the feasibility of renewable energy harvesting to meet the energy need of a dairy farm in Shahroud, Iran. Therefore, considering the available renewable resources including solar, wind, and biomass in the site and the electrical demand of the farm, the techno-economic and ...
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The current study investigated the feasibility of renewable energy harvesting to meet the energy need of a dairy farm in Shahroud, Iran. Therefore, considering the available renewable resources including solar, wind, and biomass in the site and the electrical demand of the farm, the techno-economic and environmental analyses were carried out. By using Homer software, the optimized system was selected. It was shown that although there was wind potential within the farm site, the most economical system would be a system consisting of a 100 kW biomass power plant and a 169 kW PV plant. Furthermore, by using RETScreen software, the economic and environmental analyses for the selected system were carried out. The simple and equity paybacks were 5.8 and 4.2 years for the proposed system, which confirmed the economic feasibility of the proposed system. Moreover, the gross annual GHG emission would be reduced by 91.5 %. The techno-economic and environmental analyses conducted in the current paper confirmed that the proposed system could be easily extended for other dairy farms, which resulted in a significant increase in the energy ratio of the dairy farms.
Renewable Energy Resources and Technologies
Narges Barzanooni; Hamid Reza Haghgou
Abstract
In this paper, on the basis of Green comprehensive Plan at Hakim Sabzevari University of Sabzevar, Iran, using of active solar systems at dining hall has been evaluated. On the basis of solar measured data and some solar models and relations, solar energy on the various surfaces and tilts are ...
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In this paper, on the basis of Green comprehensive Plan at Hakim Sabzevari University of Sabzevar, Iran, using of active solar systems at dining hall has been evaluated. On the basis of solar measured data and some solar models and relations, solar energy on the various surfaces and tilts are evaluated. Then electricity and thermal energy consumption are measured and new efficient lighting systems are introduced. Then photovoltaic/thermal panels and one ended evacuated tube solar collector for façade and rooftop installation are chosen. Results shows that 36683 Nm 3 /year natural gas and 87.6 tone/year pollutant are reduced. Payback time of the system based on internal energy carrier and export electricity price are 21.3 and 3.9 years respectively.
Renewable Energy Resources and Technologies
Saeed Karimian Aliabadi; Sepehr Rasekh
Abstract
In this study, an unsteady aerodynamic simulation is performed to realize the influences of platform surge motion on the aerodynamic performance of a high capacity offshore floating wind turbine. A dynamic model with pitch angle control system is utilized to propose a more realistic model of wind turbine ...
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In this study, an unsteady aerodynamic simulation is performed to realize the influences of platform surge motion on the aerodynamic performance of a high capacity offshore floating wind turbine. A dynamic model with pitch angle control system is utilized to propose a more realistic model of wind turbine and also achieve the rated condition of the rotor. The transient effect of platform surge motion on power coefficient, thrust coefficient and blade pitch angle also is investigated. The 5 MW NREL wind turbine is selected for the simulations. The unsteady aerodynamic model contains unsteady blade element momentum method, dynamic stall and dynamic inflow models. The in-home aerodynamic code and the control system model are implemented in MATLAB/SIMULINK software. It is revealed that reduction in mean power coefficient at tip speed ratios less that 7 is expected by amount of 12-15 % at surge amplitude of 2m and frequency of 0.1 Hz. For high tip speed ratios, the trend is reverse with respect to fixed-platform case. The mean thrust coefficient is also reduced for many tip speed ratios with maximum loss of 32 %. The mean blade control pitch angle is increased due to the surge motion. Since the influence of changing amplitude and frequency of disturbances depends on the tip speed ratio, therefore the special bound of this parameter is being proposed.
Renewable Energy Resources and Technologies
Hadi Farzan
Abstract
The present study investigates the effectiveness of thermostat control strategy in cooling energy consumption in residential buildings. To evaluate the energy consumption, two scenarios including a residential zone with and without the thermostat control system are assumed. The TRNSYS software provides ...
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The present study investigates the effectiveness of thermostat control strategy in cooling energy consumption in residential buildings. To evaluate the energy consumption, two scenarios including a residential zone with and without the thermostat control system are assumed. The TRNSYS software provides an efficient numerical tool to model and evaluate a cooling system. Furthermore, since solar-powered cooling systems for residential air-conditioning are receiving growing and significant interest, a hot-water fired absorption chiller coupled with evacuated tube collectors is considered as the cooling system. The results reveal that the cooling systems consume a large amount of energy in hot climate zones without employing the thermostatic control. Therefore, cooling energy has great potential for a significant saving in hot climates. It is illustrated that the thermostat strategy has an obvious impact on such energy saving. In the current study, employing the thermostat in 90m2 residential building results in saving energy by up to 36%.
Renewable Energy Resources and Technologies
Reza Rahimi; Alireza Shirneshan
Abstract
In this study, the effects of hydrogen and hydroxygen additions and oxygen enrichment on the emission characteristics of a gasoline engine (EF7) were investigated and compared with each other. The simulation was launched by GT-Power at different engine speeds with 5 % to 15 % volume fractions for both ...
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In this study, the effects of hydrogen and hydroxygen additions and oxygen enrichment on the emission characteristics of a gasoline engine (EF7) were investigated and compared with each other. The simulation was launched by GT-Power at different engine speeds with 5 % to 15 % volume fractions for both of oxygen and hydrogen enrichment and 4.5 % to 9 % volume fractions of hydroxygen addition in the intake gas, respectively. In addition, the model was validated by experimental data. The results showed that CO emission decreased from 11 % to 28 % in the hydrogen-enrichment condition. Moreover, carbon monoxide production was reduced from 28 % to 42 % for hydroxygen addition, and this pollutant emission experienced a reduction of 51 % to 67 % for oxygen enrichment. According to the results, HC emission decreased up to 13% in the hydrogen-enriched air condition, and it was reduced from 30 % to 43 % during hydroxygen addition. In addition, HC emission experienced maximum reduction of 47 % to 68 % during oxygen addition. On the other hand, there was an opposite trend for NOx emission. It was observed that NOx emission increased by around 40 % and 75 % for hydrogen and hydroxygen enrichment, respectively. Moreover, nitrogen oxides enhanced 2 to 5 times during oxygen enrichment, compared to that in the normal condition of the engine. Results showed that 15 % oxygen enrichment and 9 % hydroxygen enrichment had significant effect on the reduction of HC and CO emissions, and oxygen enrichment had greater effect on the rise of NOx emissions than hydrogen and hydroxygen additions.
Renewable Energy Resources and Technologies
Reza Roohi; Alireza Bahramian; Sepideh Samghani
Abstract
Ground thermal energy as a clean and sustainable energy source has received significant attention lately. Several strategies and hybrid configurations have been proposed to harvest geothermal energy for air conditioning and industrial purposes. The possibility of moist soil freezing in the vicinity of ...
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Ground thermal energy as a clean and sustainable energy source has received significant attention lately. Several strategies and hybrid configurations have been proposed to harvest geothermal energy for air conditioning and industrial purposes. The possibility of moist soil freezing in the vicinity of borehole tubes is known to be the source of several benefits and difficulties. The high storage capacity during the freezing process and the structural damage are the major advantages and disadvantages of the thawing phenomenon, respectively. In the present study, the numerical simulation of the freezing process around the U-tube configuration of boreholes accompanied by the solar energy injection as the auxiliary heat source is investigated. Lower values of cold stream temperature result in the higher amount of recovered heat, while increasing the injected heat temperature intensifies the heat regaining. Moreover, the energy absorbed by the ice layer around the tube is directly related to the cold stream temperature.
Renewable Energy Resources and Technologies
Negin Maftouni; Kiana Motaghedi
Abstract
Traditional fossil fuels, which are also depleting cause environmental problems. A significant portion of global energy consumption is due to building air conditioning systems. Nowadays, considerable attention is drawn to renewable and sustainable energy sources to support the energy requirements of ...
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Traditional fossil fuels, which are also depleting cause environmental problems. A significant portion of global energy consumption is due to building air conditioning systems. Nowadays, considerable attention is drawn to renewable and sustainable energy sources to support the energy requirements of buildings. In this study, a solar absorption chiller was designed for a three-floor residential building in hot and arid climate. At first, thermal loads in the building were calculated using Carrier software. The material and color of the exterior walls, as well as window types, were changed to reduce the heat transfer coefficient and get an optimum design. Results indicate that by using the optimum design, maximum heating load reduction and maximum cooling load reduction can be achieved with approximate rates of 37 % and 12 %, respectively. Considering safety factor and based on the maximum cooling load, a single-effect LiBr-water solar absorption chiller was designed for the optimum building. Two different scenarios were suggested using two types of flat plate and evacuated tube collector. Results show that in the case of evacuated tube collector the net collector area of 254.18 m2 is sufficient to supply the cooling power. Implementing flat plate collectors would result in occupying an area of 398.5 m2. Regarding the limitation of total area of roof and efficiency issues, the evacuated tube collector is the best option.
Renewable Energy Resources and Technologies
Mohammed Ibrahim Shaba; Aliyu Mohammed; Dauda Solomon Musa; Balami Ayuba Audu; Yunusa Baba Katamba
Abstract
Internationally exploited lubricants are derived from coal and petroleum. Due to their high consumption and effects of their long-term pollution on the environment, it is imperative to use renewable and cheap feedstock for the synthesis of bio-based lubricants. This study presents the synthesis and optimization ...
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Internationally exploited lubricants are derived from coal and petroleum. Due to their high consumption and effects of their long-term pollution on the environment, it is imperative to use renewable and cheap feedstock for the synthesis of bio-based lubricants. This study presents the synthesis and optimization process of Ethylene Glycol (EG) based bio-lubricant from palm kernel oil. Palm Kernel Methyl Ester (PKME) was synthesized at a reaction time of 60 min, a molar ratio of oil: methanol 1:6, a temperature of 60 oC, and catalyst of 1 % wt/wt (in-situ transesterification) via reactive extraction. Box–Behnken design (BBD) in response surface methodology (RSM) was applied to this experimental layout. The effects of molar ratio, reaction time, and temperature on the synthesis of palm kernel biolubricant (PKBL) were evaluated. The PKBL structure was characterized by Fourier Transform Infra-Red (FT-IR) and Gas Chromatography-Mass Spectrophotometer (GC-MS) analysis, showing favorable lubricating properties. The PKME yielded 94.53 wt% based on the weight of the oil, while transesterification of the in situ derived PKME with EG yielded 93.08 wt% of the EG ester (Biolubricant). The maximum biolubricant recovery was 81.48 wt% obtained at a molar ratio of 3:1, time of 2.48 h, and temperature of 135 oC. The temperature and mole ratio were established to be the most significant terms. PKBL characteristics conformed to ISO VG criteria and had high potential for biolubricant feedstock.
Renewable Energy Resources and Technologies
Mojtaba Moravej; Fatemeh Namdarnia
Abstract
Solar water heaters are good tools for saving fuel. The main component of these water heaters is collectors, which are responsible for absorbing solar energy and transferring it to the working fluid with the least heat dissipation. The present study is an experimental study of the performance of the ...
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Solar water heaters are good tools for saving fuel. The main component of these water heaters is collectors, which are responsible for absorbing solar energy and transferring it to the working fluid with the least heat dissipation. The present study is an experimental study of the performance of the solar semispherical collector with 1 m2 of absorber area at different volumetric flow rates. Water was used as the working fluid with the volumetric flow rate between 0.005-0.0166 kg/s, and the experiment was conducted in the ASHRAE 93 standard conditions. The results showed that the efficiency of semispherical solar collector increased as the flow rate of the working fluid increased, such that the highest efficiency, which is 67%, belonged to mass flow rate 0.0166 kg/s. In addition, the difference between outlet and inlet temperatures decreased due to the system being closed during the test. In addition, according to the experiments, the reduction of radiation and wind speed did not have any significant effect on the efficiency and outlet temperature of the collector. Finally, parameters such as inlet and outlet temperature of collector, ambient temperature, ambient radiation intensity and their effect have been investigated empirically on the collector efficiency graph.
Renewable Energy Resources and Technologies
Mohammad Ahmadzadehtalatapeh; Shahrokh Khaki
Abstract
The application of phase change material (PCM) for energy conservation purposes in the residential buildings was investigated in the present study. Two types of building in terms of materials as the lightweight building (LWB) and heavyweight building (HWB) located in a high cooling load demanding region ...
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The application of phase change material (PCM) for energy conservation purposes in the residential buildings was investigated in the present study. Two types of building in terms of materials as the lightweight building (LWB) and heavyweight building (HWB) located in a high cooling load demanding region of Iran were considered for the study. Different types of PCM from organic and inorganic categories were examined to determine the most appropriate type of the buildings in terms of indoor air conditions and yearly required cooling load. The buildings in the existing form and with an added layer of PCM were simulated hourly, and indoor air conditions and yearly cooling loads were determined. EnergyPlus software was used for this purpose. The study revealed that the LWB with the added layer of calcium chloride hex hydrate (CCH) had the minimum yearly required cooling load with about 39.8 GJ, and 25.7% reduction in the yearly cooling load was observed and the HWB had the best performance in terms of yearly required cooling load with the added n-eicosone (N.EIC) layer with about 28.8 GJ, which is a 47.1% reduction in the yearly cooling load. After determining the proper PCM for the buildings, the recommended PCM was planned to be positioned in the external layer, mid-layer, and internal layer to examine the position effect on the yearly required cooling load
Renewable Energy Resources and Technologies
Seyed Amir Hossein Zamzamian; Mohsen Mansouri
Abstract
The enhancement of the thermal performance of Vacuum Tube Solar Collectors (VTSC) was studied by using alumina nanofluid as working fluid. VTSC is a simple and commonly utilized type of collector. This study established the heat transfer experimental model of all glass VTSCs used in a forced-circulation ...
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The enhancement of the thermal performance of Vacuum Tube Solar Collectors (VTSC) was studied by using alumina nanofluid as working fluid. VTSC is a simple and commonly utilized type of collector. This study established the heat transfer experimental model of all glass VTSCs used in a forced-circulation solar water heating system using alumina nanofluid as base fluid. Al2O3 (with an average particle size of 15 nm) nanoparticles were provided and utilized to prepare nanofluids at a low mass concentration (0.5–1 wt.%). The thermal performances of VTSC were 15.3%, 25.7%, and 27.2% for the deionized water and Al2O3/water nanofluids with 0.5 and 1.0 wt. % as the working fluid, respectively. Generally, for Al2O3/water nanofluids with mass concentrations of 0.5 and 1.0 wt. %, the thermal performance increased by 67.9% and 77.7%, respectively, superior to that of vacuum tube using deionized water as the working fluid. Experimental results also showed that, for all three experimental tests, the thermal efficiency of the VTSC would increase by enhancing the average solar radiation.
Renewable Energy Resources and Technologies
Fariba Heidarpour; Ghazanfar shahgholian
Abstract
The sustainability of hydraulic turbines was one of the most important issues considered by electrical energy provider experts. Increased electromechanical oscillation damping is one of the key issues in the turbines sustainability. Electromechanical oscillations, if not quickly damp, can threaten the ...
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The sustainability of hydraulic turbines was one of the most important issues considered by electrical energy provider experts. Increased electromechanical oscillation damping is one of the key issues in the turbines sustainability. Electromechanical oscillations, if not quickly damp, can threaten the stability of hydraulic turbines and causes the separation of different parts of the network form each other, specifically ejecting the generators from the turbine. In this paper, a Round-robin scheduling algorithm was used based on a neural network and simulations were investigated by several methods. Thus, using the designed Round-robin scheduling algorithm, we can find three parameters simultaneously. So optimal outputs can determine by these three parameters, which would be investigated as the optimal output range. In other words, besides using other algorithms capability, it can eliminate some of their disadvantages. The Round-robin scheduling algorithm is more suitable for large and extensive systems, due to reducing the number input variables and have a non-linear and resistant structure at the same time, This algorithm can actually use for optimizing any other controlling methods.
Renewable Energy Resources and Technologies
Hediyeh Safari; Fateme Ahmadi Boyaghchi
Abstract
This research is concerned with the design and analysis of a geothermal based multi-generation system by applying both conventional and advanced exergy and exergoeconomic concepts. The proposed energy system consists of a dual-organic Rankine cycle (ORC) to vaporize liquefied natural gas (LNG) and produce ...
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This research is concerned with the design and analysis of a geothermal based multi-generation system by applying both conventional and advanced exergy and exergoeconomic concepts. The proposed energy system consists of a dual-organic Rankine cycle (ORC) to vaporize liquefied natural gas (LNG) and produce electricity. A proton exchange membrane(PEM) electrolyzer is employed to produce hydrogen by receiving the power and coolant heat waste of dual ORC. Moreover, cooling effect is produced during LNG regasification by utilizing the cryogenic energy of LNG. Parametric studies are conducted to assess the effects of substantial input parameters, namely turbine 1 inlet pressure, mass rate of upper cycle, geothermal mass flow rate, on the various parts of exergy destruction and cost rates within the major components.
Renewable Energy Resources and Technologies
Mehdi Jahangiri; Akbar Alidadi Shamsabadi; Hamed Saghaei
Abstract
Canadian researchers are now trying to exploit much more energy from solar sources, hydropower, wind, and biomass. Given the fact that reducing the carbon pollutant level is a political priority in Canada, this paper studies the feasibility of providing sanitary hot water and space heating demands of ...
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Canadian researchers are now trying to exploit much more energy from solar sources, hydropower, wind, and biomass. Given the fact that reducing the carbon pollutant level is a political priority in Canada, this paper studies the feasibility of providing sanitary hot water and space heating demands of a four-member family in 10 provinces in this country. The feasibility analysis was performed by T*SOL Pro 5.5 software, and radiation data were obtained by MeteoSyn software. Results indicated that the most suitable station in terms of using solar water heater was Regina, which supplied 35 % of the total heat load for space heating and sanitary hot water purposes. This accounted for 5074 kWh of heat for space heating (25 % of demand) and 3112 kWh energy for sanitary hot water (94 % of demand) using a 40 m2 solar collector. In addition, results are indicative of an annual amount of saving up to 2080 kg of CO2 in the Regina station and an annual reduction of 984 m3 in natural gas for this station. In conclusion, Canada has a potentially alluring market to utilize solar water heaters for providing sanitary hot water for the residential sector.
Renewable Energy Resources and Technologies
Alireza Rastikerdar
Abstract
The municipal solid waste in Landfill is transformed into landfill gas during a biochemical conversion process called bio-degradation. Gas release from landfills has potentially different environmental effects; therefore, assessing and forecasting the rate of production and release of gas from landfill ...
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The municipal solid waste in Landfill is transformed into landfill gas during a biochemical conversion process called bio-degradation. Gas release from landfills has potentially different environmental effects; therefore, assessing and forecasting the rate of production and release of gas from landfill sites is important for designing these sites and for the successful exploitation of gases as energy sources. In this study, by using LandGEM model, in the span of 2018-2037, the amount of gases produced from the municipal landfill of Sirjan, Iran has been predicted. According to the results, the largest amount of landfill gas emission will be in 2038, a year following the last year of disposal of the waste to the landfill. The total amount of produced gas, carbon dioxide, methane, and NMOCs will be 1.219E+05, 8.932E+04, 3.255E+04, and 1.399E+03 tons per year in 2038 for Sirjan. In the next step, the LandGEM outputs were imported into OpenLCA software. The health and environmental effects of landfill gas emissions were evaluated by USEtox and traci method, respectively, in this software. According to the USEtox method, the value of total health effects was obtained as 0.032496 CTUh; in addition, by using the traci method, the most environmental burden falls in the impact categories of global warming, photochemical ozone formation, ecotoxicity, acidification, respiratory effects. By making sound and suitable plans as of this 20-year period and implementing tube in this place, greenhouse gas emissions to the atmosphere can probably be prevented. It is also suggested that landfill gases be used to supply energy to the Sirjan recycling plant.
Renewable Energy Resources and Technologies
Aondoyila Kuhe; Victor Terhemba Achirgbenda; Mascot Agada
Abstract
The optimum design of solar energy systems strongly depends on the accuracy of solar radiation data. However, the availability of accurate solar radiation data is undermined by the high cost of measuring equipment or non-functional ones. This study developed a feed-forward backpropagation artificial ...
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The optimum design of solar energy systems strongly depends on the accuracy of solar radiation data. However, the availability of accurate solar radiation data is undermined by the high cost of measuring equipment or non-functional ones. This study developed a feed-forward backpropagation artificial neural network model for prediction of global solar radiation in Makurdi, Nigeria (7.7322 N long. 8.5391 E) using MATLAB 2010a Neural Network toolbox. The training and testing data were obtained from the Nigeria metrological station (NIMET), Makurdi. Five meteorological input parameters including maximum and temperature, mean relative humidity, wind speed, and sunshine hour were used, while global solar radiation was used as the output of the network. During training, the root mean square error, correlation coefficient and mean absolute percentage error (%) were 0.80442, 0.9797, and 3.9588, respectively; for testing, a root mean square value, correlation coefficient, and mean absolute percentage error (%) were 0.98831, 0.9784, and 5.561, respectively. These parameters suggest high reliability of the model for the prediction of solar radiation in locations where solar radiation data are not available.
Renewable Energy Resources and Technologies
Ali Mostafaeipour; Mohammad Saidi Mehrabad; Mojtaba Qolipour; Mohadese Basirati; Mostafa Rezaei; Amir Mohammad Golmohammadi
Abstract
The present study aimed at ranking and selecting the superior geothermal project for hydrogen production in 14 provinces of Iran using a multi-objective optimization fuzzy hybrid approach through analyzing the ratio (fuzzy Moora) and expanded entropy weighting method. In this research, the extended entropy ...
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The present study aimed at ranking and selecting the superior geothermal project for hydrogen production in 14 provinces of Iran using a multi-objective optimization fuzzy hybrid approach through analyzing the ratio (fuzzy Moora) and expanded entropy weighting method. In this research, the extended entropy weighing method and the Fuzzy-Moora approach were utilized to weigh the criteria and project the ranking, respectively. In this research, 13 criteria for ranking the geothermal projects in Iran have been selected for hydrogen production. At first, the technical-economic feasibility of the projects was carried out in Homer software, and then the ranking process was performed with the proposed hybrid approach. The results showed that among 14 studied provinces using geothermal energy, the provinces of Bushehr, Hormozgan, Isfahan, Mazandaran, East Azarbaijan, Fars, Qazvin, Zanjan, Ardebil, Khorasan Razavi, Kerman, Sistan and Baluchestan, South Khorasan and West Azarbaijan were ranked in that order in terms of hydrogen production.
Renewable Energy Resources and Technologies
Ali Moazemi Goudarzi; Shahab Alizadeh; Hesam Ramezanzadeh
Abstract
In this paper, the absorbent carryover effect in a designed counter-flow enthalpy exchanger is investigated. In a built prototype of the liquid desiccant dehumidifier, air and the absorbent solution are in contact and flow through a packed multi-channel polymer tower in a counter-flow pattern. To avoid ...
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In this paper, the absorbent carryover effect in a designed counter-flow enthalpy exchanger is investigated. In a built prototype of the liquid desiccant dehumidifier, air and the absorbent solution are in contact and flow through a packed multi-channel polymer tower in a counter-flow pattern. To avoid the absorbent carryover, the tower is equipped with an eliminator. Experimental measurements show that applying wick of hydrophilic type material to the channels' surfaces of the eliminator and the enthalpy exchanger, while increasing the rate of dehumidification, reduces the solution carryover effect, however, it does not eliminate it. To eliminate the effect, pumping the solution into the tower is interrupted periodically. It was found that by adjusting the pump switching frequency, the carryover effect can be eliminated. The best result is achieved when the period of switching on state is about a quarter of the off state one and the total period is about 25 seconds. Since the solution pump is turned off frequently, the cost of electrical power is reduced significantly. Also, the measurements show that while the dehumidification ability of the tower is improved in a steady state operation its regeneration performance is not.
Renewable Energy Resources and Technologies
Nemat Keramat Siavasha; Gholamhasan Najafi; Teymour Tavakoli; Barat Ghobadian; Esmail Mahmoodi
Abstract
Ducted wind turbines are a kind of small wind turbine having a diffuser or any other shape around the rotor which increases the air flow through the blades and absorbs more power. In the present study, a small wind turbine was ducted with a relatively simple ring and its performance was investigated ...
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Ducted wind turbines are a kind of small wind turbine having a diffuser or any other shape around the rotor which increases the air flow through the blades and absorbs more power. In the present study, a small wind turbine was ducted with a relatively simple ring and its performance was investigated in a wind tunnel. The duct is shaped using rolling steel sheets on a sloping surface and finally fabricated in double-glazed surfaces. The turbine utilizes polyester resin glass fiber-armed composite hollow blades. Bare turbine produces 165 watts in its highest power generation mode which can reach 282 watts when it is ducted. The evaluation of the system in the wind tunnel showed that the power generation of the ducted system compared to a conventional turbine was 14 % higher on average. Furthermore, the rotor speed of the ducted turbine was 45 % higher than the bare one which increases the tip speed ratio (TSR). In this study, TSR increment raised the absorbed power in the developed wind turbine.
