| 1. |
- Ali, Faheem, et al.
(författare)
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Self-powered photo-thermo electrochemical sensor for harvesting of low photo thermal energy
- 2020
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Ingår i: Energy Sources, Part A: Recovery, Utilization and Environmental Effects. - : Informa UK Limited. - 1556-7036 .- 1556-7230.
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Tidskriftsartikel (refereegranskat)abstract
- An ecofriendly design of low-cost electrochemical sensor activated by low-grade photo-thermal energy can be a prime stepping-stone for the perspective developments of various renewable energy conversion and utilization schemes. In this study, an investigation of n-type indium arsenide (n-InAs)/aqueous solution of orange dye (OD)/Zinc (Zn) sensor was carried out at various molarities of 1, 2, and 3 mM of electrolytes under variable visible light illumination. OD was employed as a photo-active electrolyte, which is nontoxic and water-soluble organic semiconductor material. n-InAs was employed as a photoactive electrode while Zn was used as a counter metal electrode in our sensor configuration. The operation mechanism is based on the electrochemical-cell principle associated with photo-thermal energy splint. Photoinduced current-voltage characteristics, sensor stability, and a real-time transient characteristics were investigated using three different concentrations of electrolyte. A relatively improved response time was attained of 3 mM OD-electrolyte sensor with an inter-electrode distance of 3 mm under a light illumination of 95 mW/cm2 and a temperature gradient of 1.5°C.
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| 2. |
- Bahrami, Ataallah, et al.
(författare)
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The effect of grinding circuit efficiency on the grade and recovery of copper and molybdenum concentrates
- 2022
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Ingår i: Energy Sources, Part A. - : Taylor & Francis Group. - 1556-7036 .- 1556-7230. ; 44:3, s. 8121-8134
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Tidskriftsartikel (refereegranskat)abstract
- The efficiency of grinding and flotation process in copper-molybdenum processing circuit, largely affected by performance of thickeners and hydrocyclones devices. The goal of this paper is to investigate the effect of the rate-limiting factors on the performance of these devices and consequently on grinding and separation efficiency of the molybdenum processing circuit. So, a full process mineralogical study have been carried out on outputs of thickeners and hydrocyclone of the molybdenite flotation circuit. According to the results, coarse-grained fractions (>50 μm) of the planar molybdenite will not necessarily be recovered by thickener and hydrocyclones. This is especially true for hydrocyclones when the inlet-load rate is high, i.e., the erroneous discharge of planar molybdenite particles from the overflow of hydrocyclone, as well as their floatability in the thickener overflow, can be attributed to the effect of particle shape and size. This issue harms the grade and recovery of flotation due to the increase in the amount of circulating load (regrinding) and consequently the generation of fine particles (<10 μm) in the hydrocyclone-milling circuit. On the other hand, the almost spherical particles of copper minerals, as well as the nonplanar molybdenite fine-grained particles, are easily removed from the hydrocyclone underflow or settled in thickeners. The introduction of copper mineral particles into molybdenum concentrate and vice versa has reduced the quality of the produced concentrate and undesirable flotation performance.
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| 3. |
- Chelgani, Saeed Chehreh, et al.
(författare)
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Estimation of heavy and light rare earth elements of coal by intelligent methods
- 2021
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Ingår i: Energy Sources, Part A. - : Taylor & Francis. - 1556-7036 .- 1556-7230. ; 43:1, s. 70-79
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Tidskriftsartikel (refereegranskat)abstract
- Since last two decades, several investigations in various countries have been started to discover new rare earth element (REE) resources. It was reported that coal can be considered as a possible source of them. REE of coal occur in low concentrations, and their detection is a complicated process; therefore, their predictions based on conventional coal properties (proximate, ultimate and major elements (ME)) may have several advantages. However, few studies have been conducted in this area. This study examined relationships between coal properties and REE (HREE and LREE) for a wide range of coal samples (708 samples). Variable importance measure (VIM) by Mutual information (MI) as a new feature selection method was applied to consider the heterogeneous structure of coal and assess the individual relation between coal parameters and REE to select the compact subsets as input variables for modeling and improve the performance of prediction. VIM by MI showed that Si-Carbon, and Al-Hydrogen are the best subsets for the prediction of HREE and LREE concentrations, respectively. A boosted neural network (BNN) model as a new predictive tool was used for REE prediction. BNN can significantly reduce generalization of error. Results of BNN models showed that the HREE and LREE concentrations can satisfactory estimate (R 2 : 0.83 and 0.89, respectively). Results of this investigation were approved that MI-BNN can be used as a potential tool for prediction of other complex problems in energy and fuel areas.
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| 4. |
- Chelgani, Saeed Chehreh
(författare)
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Prediction of specific gravity of Afghan coal based on conventional coal properties by stepwise regression and random forest
- 2023
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Ingår i: Energy Sources, Part A. - : Taylor & Francis. - 1556-7036 .- 1556-7230. ; 45:2, s. 4323-4334
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Tidskriftsartikel (refereegranskat)abstract
- Coal can be considered as the main fuel for electricity generation in Afghanistan. However, there is a quite limited data available about the overall quality, distribution, and character of coals in Afghanistan. Specific gravity (S.G) of coal as a key factor can be used for the estimation of potential tonnage production and be a fundamental parameter for the selection of coal washery process method. However, there is no investigation which comprehensively explores relationships between S.G and coal properties. In this investigation, the potential of S.G prediction based on conventional properties for Afghan coal samples was explored by stepwise regression and random forest. Pearson correlation (r) and variable importance measurement (VIM) of random forest (RF) were applied to select the most effective variables among conventional parameters for the S.G prediction. Results of VIM indicated that ash and carbon content of coal samples had the highest importance for the S.G prediction. Stepwise regression and RF models were developed based on these two coal variables. Testing the generated models indicated that S.G of Afghan coals can quite accurately predict by these models (R2 > 0.90). Modeling outcomes showed that the highest S.G (S.G > 2) for Afghan coal occurred when ash was higher than 40% and carbon was lower than 30%.
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| 5. |
- Cuvilas, Carlos Alberto, et al.
(författare)
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The Characterization of Wood Species from Mozambique as a Fuel
- 2014
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Ingår i: Energy Sources, Part A. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 36:8, s. 851-857
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Tidskriftsartikel (refereegranskat)abstract
- The efficient utilization of fuelwood as a source of energy is strongly dependent on the properties of the biomass. This study characterizes common hardwood species from Mozambique and evaluates their quality as a fuel. Disc samples, taken at breast height, from Afzelia quanzensis Welwn, Millettia stuhlmannii Taub, Pterocarpus angolensis DC, Sterculia appendiculata K. Schum, Pericopsis angolensis Meeuwen, Acacia nigrescens Oliv., Pseudolachostylis maprounaefolia Pax, and Icuria dunensis Wieringa, were collected from three provinces in Mozambique. Chemical and physical properties were analyzed. The raking of the species as fuel was performed using fuelwood value index. The higher heating value varied between 19.38 and 21.50 MJ/kg dry weight. The concentration of lignin ranged from 21.96 up to 36.69% weight dry basis (wt% d.b.), and ash free. All studied species showed very low concentrations of Si, S, and Cl. Ash content varied between 0.76-3.71 wt% (d.b.), while the basic density ranged from 536 to 1,111 k gm(-3). Heavy metals were also determined and their concentrations were below the values reported in the literature. The species Acacia nigrescens had the highest fuelwood value index and it was closely followed by Icuria dunensis and Millettia stuhlmannii. The worst ranked was Sterculia appendiculata.
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| 6. |
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| 7. |
- Han, Jen-Yu, et al.
(författare)
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Impact of temperature and solar irradiance in shadow covering scenarios via two-way sensitivity analysis for rooftop solar photovoltaics
- 2024
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Ingår i: Energy Sources, Part A. - : Taylor & Francis. - 1556-7036 .- 1556-7230. ; 46:1, s. 3165-3176
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Tidskriftsartikel (refereegranskat)abstract
- Solar irradiance and temperature are two primary factors that affect the energy generation efficiency of solar photovoltaic (PV) systems, meaning that climate change may significantly impact the production of solar energy in the future. In this study, a two-way sensitivity analysis is carried out to determine the energy generation potential under future climate change conditions, and conditions of shadow covering are also considered. The simulation results indicate that the impact of solar irradiance causes the most variation in energy generation, and that shadow covering has a weak impact on the output. In the one-way sensitivity analysis, solar irradiance makes a +/- 18% difference in energy generation, whereas shadow covering represents about +/- 2%. In the future trend of climate change in the world and Taiwan, the energy generation potential can decrease up to 21% and increase 8%, respectively, mainly corresponded by solar irradiance. We suggest that compared with the issue of temperature, the efficiency of solar irradiance usage is more important, especially in view of the global trend toward solar irradiance loss. Taiwan also suffers the issue, but the different trend of climate change impact may make the challenge different.
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| 8. |
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| 9. |
- Hussain, M., et al.
(författare)
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Optimization of lithium adsorption from seawater via aluminum chloride as adsorbent using response surface methodology
- 2024
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Ingår i: Energy Sources, Part A. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 46:1, s. 2907-2921
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Tidskriftsartikel (refereegranskat)abstract
- Lithium extraction from natural resources is an accelerating field of research owing to its growing demand in the medical, nuclear, battery, and air conditioning industries. Lithium compounds are used in various industries, including ceramics, glass, lubricant gases, rocket propellant, and aluminum production. The extraction of lithium from seawater via adsorption using AlCl3.6 H2O as an adsorbent is investigated in this study. The effect of process parameters such as pH, temperature, contact time, the molar ratio ([Al3+]/[Li+]), and stirring rate on process efficiency is investigated and optimized. The response surface methodology (RSM) is used to investigate the effects of operating parameters and choose the optimal configuration. A standard synthetic solution containing 50 ppm lithium is prepared and experimented with facilitating comprehension of the procedure. The adsorption efficiency of a synthetic solution is 88% at optimized values, while that of seawater is 78.5%. Seawater has a lower efficiency because it contains ions such as Mg2+, Ca2+, K+, and Na+ that compete for active points/sites during adsorption with lithium ions (Li+).
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| 10. |
- Lohani, Sunil Prasad, et al.
(författare)
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Anaerobic co-digestion of food waste, poultry litter and sewage sludge : seasonal performance under ambient condition and model evaluation
- 2021
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Ingår i: Energy Sources, Part A. - : Taylor & Francis Group. - 1556-7036 .- 1556-7230. ; , s. 1-16
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Tidskriftsartikel (refereegranskat)abstract
- With the increasing population, food waste, sewage sludge, and poultry litter management problem are scaling up even in low-income countries. The management of these wastes has therefore been challenging. Anaerobic digestion of food waste alone is not very stable due to its acidic nature and high degradability whereas sewage sludge and poultry litter have low biochemical methane potential and a high nitrogen concentration. Co-digestion of suitably selected substrate leads to enhanced biogas production potential, system stability due to synergetic effects, and resolving the problem of waste management in the vicinity in a holistic approach. However, these wastes have varying characteristics and composition, in terms of carbon-to-nitrogen (C/N) ratio, pH, and alkalinity. In addition, millions of the rural household bio- digesters operating in low-income countries are working under ambient conditions and are primarily unheated. Therefore, there is a need of research to assess the viability of biogas production of co-digestion of all above substrates in an optimal mixing ratio operating in an ambient temperature condition. In this study, food waste (FW), sewage sludge (SS), and poultry litter (PL) were co-digested at ratios (SS: PL: FW: 3:2:1, 2:1:1, 1:1:1) with 8% total solid (TS) content at ambient temperature in summer and winter seasons. Biogas yield was highest with mixing ratio of 2:1:1 with the values of 640 L/kgVS in summer while it gave extremely low biogas yield of 106 L/ kgVS in winter. The 2:1:1 mixture also had the highest methane composition of nearly 65% as well as the highest VS removal efficiency of 60%, making it the most viable option for increasing biogas production. Mathematical modeling results using Gompertz model and first-order model predicted well with R2 value ranging from 0.91 to 0.98, which upheld the experimentally obtained values. Findings from this study suggest that co-digestion substrates (SS:PL:FW) mixing ratio of 2:1:1 is an optimized ratio among the studied co-substrate ratio for enhanced biogas production. Furthermore, winter biogas yield is almost one sixth of summer biogas yield, which means use of temperature enhancement techniques to anaerobic digesters operating at ambient conditions would be essential to increase the biogas yield during winter.
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| 11. |
- Rout, Auroshis, et al.
(författare)
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A Monte Carlo based approach for exergo-economic modeling of solar water heater
- 2020
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Ingår i: Energy Sources, Part A. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; , s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- In life-cycle costing of thermal energy systems, the basis of costing could be mass or exergy and the approach followed could be deterministic or stochastics. In thermal energy systems with end products/services such as hot air, hot water, steam etc. the value addition is due to higher exergy content; therefore, exergy is a logical basis of costing and stochastics is a practical approach capturing uncertainties of input variables. This paper proposes a novel framework named as stochastic Monte Carlo-based exergy costing (SMXC) for assessment of solar hot water systems. The annual hours of operation, maintenance cost, service life, and capital cost have been identified as highly sensitive input variables. The costs based on mass and exergy content of hot water in deterministic life-cycle costing method are estimated at 0.296 and 0.304 US cent/kg, respectively. The mean values of mass and exergy costs of hot water using Monte Carlo-based stochastics life-cycle costing method are 0.302 and 0.310 US cent/kg. A very low value (i.e. 2.4%) of the exergo-economic factor (f) for the solar water heater indicates the poor exergetic efficiency; therefore, capital investment to improve its efficiency is justified. The methodological approach can be extended to examine the probabilistic exergo-economic cost of array of thermal energy products when the parametric uncertainties play a key role.
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| 12. |
- Suarez, J. A., et al.
(författare)
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A phenomenological energy model of biomass pyrolysis under autothermal fluidized bed conditions
- 2006
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Ingår i: Energy Sources Part a-Recovery Utilization and Environmental Effects. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 28:8, s. 705-714
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Tidskriftsartikel (refereegranskat)abstract
- In Cuba a variety of types of biomass is being investigated for energy conversion through thermochemical processes into solid, liquid, and gas products. A continuous bench fluidized bed pyrolysis has been designed and is currently under testing. In this article, a transport model has been developed to simulate the axial temperature fields in a bench. The model and experimental results indicated that (1) two zones exist inside of the fluidization column, the dense bed where the exothermic and endothermic reactions are active, and the freeboard zone where the temperature of the pyrolysis product decreases continuously; (2) the bed temperature increases with an increase in the air factor. The predicted temperature is in quantitative agreement with experimental measurements.
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| 13. |
- Suarez, J. A., et al.
(författare)
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Autothermal fluidized bed pyrolysis of Cuban pine sawdust
- 2006
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Ingår i: Energy Sources Part a-Recovery Utilization and Environmental Effects. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 28:8, s. 695-704
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative pyrolysis of Cuban pine sawdust was investigated using an autothermal fluidized bed reactor. Biomass particles were fed continuously (8.13 Kg/h) in a bed, fluidized by air gas. Experiments were conduced at three different dimensionless air factors 1, 1.5, and 2 (defined as ratio of actual air flow rate to stoichiometric air flow rate). The various physical and chemical characteristics of the pyrolysis products acquired in these conditions were identified. The results indicated that (1) the operating temperature can be correlated with the air factor; (2) the higher air factor promotes high temperature and contributes to the secondary reactions, which lead to less liquid; (3) the physicochemical characterization of the pyrolysis products indicated that the air factor, in the range studied, does not have a notable influence in their properties; (4) the liquid and char products obtained may be a potentially valuable source of chemical feedstocks.
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| 14. |
- Suresh, M., et al.
(författare)
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Performance evaluation and emission characteristics of variable compression ratio diesel engine using Argemone Mexicana biodiesel
- 2021
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Ingår i: Energy Sources, Part A. - : Informa UK Limited. - 1556-7036 .- 1556-7230. ; 43:12, s. 1511-1523
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Tidskriftsartikel (refereegranskat)abstract
- The present work is focused on the production, emission and performance characteristics at variable compression ratios (CRs) on a compression ignition multi-fuel engine using Argemone Mexicana oil methyl ester and its blends with diesel (on a quantity basis) was observed and compared with the same. The feasibility of employing Argemone Mexicana oil methyl ester as a biofuel has been determined in the present work. Experiments have been conducted at a constant engine speed of 1,500 rpm and results are obtained at different CR of 14:1, 15:1, 16:1, 17:1, and 18:1. The ratios of blends used in this experiment are D100, AME5, AME10, AME20, AME35, AME50 and AME100, where the values relate to the share of the type of fuel given by the characters. The significance of compression ratio on the engine performance and emission has been investigated and presented for all the blends of biodiesel. The optimum results are obtained AME20 at CR17, which shows that the values of brake thermal efficiency, brake power, and specific fuel consumption are superior to that of both diesel and other blends. These blends, as fuel produces less emissions of CO, HC and marginally increase in NOx compared to that of diesel.
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