Y. Tonbul
Dicle University
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Featured researches published by Y. Tonbul.
Energy Sources Part A-recovery Utilization and Environmental Effects | 2011
Candan Hamamci; Abdurrahman Saydut; Y. Tonbul; Canan Kaya; Aylin Beycar Kafadar
Abstract The safflower (Carthamus tinctorius L.) oil was extracted from the seeds of the safflower that grows in Diyarbakir, SE Anatolia of Turkey. Carthamus tinctorius L. seed oil was investigated as an alternative feedstock for the production of a biodiesel fuel. By traditional solvent extraction, oil was obtained and biodiesel was prepared from safflower by transesterification of the crude oil. A maximum conversion of 93% (oil to ester) was achieved using 100% excess methanol, i.e., molar ratio of methanol to oil is 6:1 and catalyst (NaOH) concentration of 0.5% at 65°C. The viscosity of biodiesel oil is nearer to that of petroleum diesel and the calorific value is about 5.5% less than that of diesel. The quality of biodiesel is most important for engine parts and various standards have been specified to check the quality. The important properties of safflower oil and its methyl ester (biodiesel), such as density, kinematic viscosity, flash point, iodine number, neutralization number, pour point, cloud point, and cetane number, are found out and compared to those of No. 2 petroleum diesel. Fuel properties of methyl esters of Carthamus tinctorius L. oil compare well with ASTM and EN biodiesel standards. The present experimental results support that methyl ester of safflower seed oil can be successfully used as diesel.
Energy Exploration & Exploitation | 2010
Abdurrahman Saydut; Aylin Beycar Kafadar; Y. Tonbul; Canan Kaya; Firat Aydin; Candan Hamamci
A major hurdle in commercialization of biodiesel from vegetable oil, in comparison to petroleum-based diesel fuel, is its cost of manufacturing, primarily the raw material cost. Waste cooking oil is one of the economical sources for biodiesel production. NaOH and KOH catalyzed processes for prepared of biodiesel expressed of fatty acid methyl ester were comparatively studied for refined sunflower (Helianthus annuus L) oil and waste cooking oil. Transesterification was carried out using 100% excess methanol; i.e. molar ratio of methanol to oil is 6:1 and catalyst concentration of 0.5% at 60°C. Fuel properties and specifications such as viscosity, flash point, cloud point, pour point, density, cetane number, and acidic value are determined and compared to each other and petroleum diesel. This study characterizes the fuel properties of biodiesel produced from refined sunflower oil and waste cooking oil using two different catalysts (NaOH and KOH) to provide a comprehensive understanding of biodiesels.
Energy Exploration & Exploitation | 2008
Abdurrahman Saydut; Y. Tonbul; Candan Hamamci
Asphaltite, being petroleum originated solid fossil fuel, can be converted into a variety of secondary products such as light hydrocarbon gases, liquid product and high quality fuel char by means of pyrolysis. Liquefaction of Harbul (Silopi, Turkey) asphaltite,-0.60+0.25 mm particle size, and using flash pyrolysis was performed in a fixed bed reactor with a heating rate 40°C min−1 at a temperature ranging from 400 to 800°C under nitrogen atmosphere. The effect of temperature on conversion and liquid yield was examined. The flash pyrolysis temperature resulted in a large increase in the oil yield, tar, gases, large increase in the yield of hydrocarbon gases occurred as a result of temperature at 550°C which was attributed to an increase thermal cracking of pyrolysis vapours. The yield of asphaltite liquid at the condition of 550°C reached a maximum 19.66 wt %. The asphaltenes of the pyrolytic oils were precipitated by addition of n-pentane. Pentane solubles were fractioned by column chromatography into aliphatic, aromatic and polar fractions using n-hexane, toluene and methanol, respectively. The composition of these fractions from silica gel column chromatography of oil obtained by nitrogen pyrolysis was characterized by FTIR.
Spectroscopy Letters | 1998
Mehmet Akçay; Mürüwet Yurdakoç; Y. Tonbul; Kadir Yurdakoç; Dieter Hönicke
Abstract The adsorption of ammonia and pyridine on the surface of the V2O5/MgO catalysts has been studied for the determination of the Br⊘nsted and Lewis acid sites. The data showed that the catalysts have medium Lewis acidity, but are also weak Br⊘nsted acids, having active hydroxy groups able to interact with pyridine by H-bonding and by protonation. Pyridine is a suitable basic probe for the quantification of the catalysts. 32% V2O5/MgO catalyst is the most acidic catalyst.
Energy Sources Part A-recovery Utilization and Environmental Effects | 2011
Abdurrahman Saydut; M. Z. Duz; Sait Erdogan; Y. Tonbul; Candan Hamamci
Abstract Desulfurization and demineralization by an aqueous caustic leaching method was investigated of an asphaltite sample from Harbul (Silopi, SE Anatolia, Turkey). The effects of different parameters, such as alkali concentration, time, and temperature, on the leaching efficiency were detailed and the experimental results are presented here. The caustic concentration varied from 0.1–1.0 M, temperature was 100–180°C, and leaching time varied from 4–16 h. The removal of total sulfur and ash increases with increasing alkali concentration, leaching temperature, and time. As a result of aqueous caustic leaching, the ash content of asphaltite was reduced from 32.49 to 18.00%, and 76% of combustible was recovered. Total sulfur and volatile matter content was reduced from 7.02 to 2.68% and from 46.74 to 25.10%, respectively.
Turkish Journal of Chemistry | 1999
Mürüvvet Yurdakoç; Mehmet Akçay; Y. Tonbul; Kadir Yurdakoc
Journal of Thermal Analysis and Calorimetry | 2008
Y. Tonbul
Applied Catalysis B-environmental | 2014
Y. Tonbul; Mehmet Zahmakiran; Saim Özkar
Turkish Journal of Chemistry | 2001
Y. Tonbul; Kadir Yurdakoc
Journal of Thermal Analysis and Calorimetry | 2005
M. Z. Duz; Y. Tonbul; Akın Baysal; Osman Akba; Abdurrahman Saydut; Candan Hamamci