Yazar "Atelge, M. Rasit" seçeneğine göre listele

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    A Novel Tea factory waste metal-free catalyst as promising supercapacitor electrode for hydrogen production and energy storage: A dual functional material
    (Elsevier Sci Ltd, 2021) Ozarslan, Saliha; Atelge, M. Rasit; Kaya, Mustafa; Unalan, Sebahattin
    In this study, the catalyst produced from tea factory waste (TFW) was used for the first time for hydrogen production by methanolysis of sodium borohydride (NaBH4). The produced material had a dual function as both catalyst and supercapacitor; therefore, it was named 'cap-cat'(capacitor-catalyst) by us. In this context, TFW was treated with acetic acid for 24 h at 80 degrees C. The sample was then subjected to combustion in the oven to synthesize the catalyst. Afterward, the most efficient TFW-CH3COOH catalyst was synthesized by evaluating different acid ratios, burning temperatures and times. The best conditions for the acetic acid ratio, burning temperature, and time were found out 3 M, 300 degrees C, and 60 min. The characterization of the catalyst was done using SEM-EDX, FTIR, XRD analysis. Hydrogen generation experiments from NaBH4 by methanolysis were performed at various catalyst concentrations in the range of 0.05-0.2 g, diverse NaBH4 ratio of 1 to 7.5%, and at different reaction temperatures (30-60 degrees C). The HGR of the synthesized catalyst was recorded as 3096.4, 8367.5, 11227.9, and 23,507 mLmin(-1)g(cat)(-1) for these temperatures (30, 40, 50, and 60 degrees C), respectively. Also the activation energy was calculated as 38.6 kJ mol(-1). Subsequently, the CV (cyclic voltammetry) and charge-discharge curves of the prototypes produced were substantially similar to the supercapacitor curves in the literature. Gravimetric capacitance was found to be 155F/g at a current density of 2 A/g.
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    A study on the effects of nanoparticle addition to a diesel engine operating in dual fuel mode
    (Elsevier Sci Ltd, 2022) Arslan, Esenay; Atelge, M. Rasit; Kahraman, Nafiz; uenalan, Sebahattin
    In this study, a diesel engine was operated both in dual fuel mode and with nanoparticle additives. The aim is to experimentally investigate the effect of both carbon nanotube additives and the addition of hydrogen/natural gas mixture to the combustion air in a compression ignition engine. 100%NG, 10%H2 + 90%NG, and 20%H2 + 80% NG gas mixtures were added to the diesel with and without CNT additives at a mass flow rate of 250 g/h using combustion air. 50 ppm nanoparticles were added to one liter of liquid fuel and mixed with an ultrasonic mixer to form a diesel fuel-CNT mixture. Engine tests were carried out at constant speed and four different engine loads and no-load conditions. Under all load conditions, in-cylinder pressure, brake specific fuel consumption, brake thermal efficiency, and exhaust emissions were investigated. Based on the experimental results, the combustion of CNT-added diesel fuel with gaseous fuels has made significant contributions to the basic engine performance parameters. The diesel with CNT additive reached a cylinder pressure of approximately 64 bar, while the D@50ppm + NG@90%+H2@10% mixture provided a 2% increase in in-cylinder pressure compared to diesel fuel. The D@50ppm + NG@90%+H2@10% also offered the highest value among all fuel alternatives with a brake thermal efficiency of 39% at full load, resulting in 9% more efficient than diesel fuel. Gas mixtures with CNT additives effectively reduced CO and HC emissions compared to other mixtures except for diesel and D@50ppm.
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    Öğe
    Examination of the effect on the engine of diesel-nanoparticle mixture with natural gas addition
    (Elsevier Sci Ltd, 2024) Arslan, Esenay; Atelge, M. Rasit; Kahraman, Nafiz; Unalan, Sebahattin; Ceper, Bilge A.
    Diesel engines have a broader application area and have a significant share in the transportation sector. Although there are restrictions on producing within the scope of emission standards, diesel fuel will remain important in heavy-duty vehicles for some time. Therefore, studies continue for environmentally friendly combustion and low emissions in diesel fuel. This paper reveals the results of using nanoparticle fuel with natural gas (NG) on diesel engine emissions and performance. In the experiments, the motor load was adjusted from no to full load by increasing it at 25% intervals. Three different diesel-nanoparticle blends containing 25 ppm, 50 ppm and 75 ppm carbon nanotube (CNT) were prepared and each of these blends was tested both with and without NG. In light of the test results, it has been seen that the D75ppmCNT + NG mixture is the best fuel mixture compared to both diesel and nanoparticle-added diesel since it provides the highest value in brake thermal efficiency (BTE) and the lowest value in brake specific fuel consumption (BSFC) at full load conditions. In the case of using a D75ppmCNT mixture, around 29% decrease in BSFC and about 28% increase in BTE were observed according to the diesel fuel use. In terms of emissions, when NG is added to the D + CNT fuel mixtures, there is an increment in CO and HC emissions and a slight reduction in NOx emissions at low and medium load.