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Öğe Biodiesel Production via Transesterification from Safflower (Carthamus tinctorius L.) Seed Oil(Taylor & Francis Inc, 2011) Hamamci, C.; Saydut, A.; Tonbul, Y.; Kaya, C.; Kafadar, A. B.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 degrees 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.Öğe Chemical Leaching on Sulfur and Mineral Matter Removal from Asphaltite (Harbul, SE Anatolia, Turkey)(Taylor & Francis Inc, 2011) Saydut, A.; Duz, M. Z.; Erdogan, S.; Tonbul, Y.; Hamamci, C.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 degrees 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.Öğe Investigation of pyrolysis kinetics of humic acids from low rank Anatolian coal by thermal analysis(Taylor & Francis Inc, 2007) Tonbul, Y.; Erdogan, S.Thermogravimetric analysis (TGA) of humic acid samples from low rank Anatolian (east of Turkey, Bingol) coal were investigated under atmospheric pressure. The samples were subjected for the decomposition of organic matter ambient to 800 degrees C at four different heating rates (5, 10, 15, and 20 degrees C min(-1)). The humic acid samples were started at decomposition between 170 - 206 degrees C and amount of residues varied 55-60% according to heating rate. Each of samples was showed a single step mass loss. TG/DTG data of samples were analyzed to determine activation energy values by Coats and Redfern method and Arrhenius method. Activation energy values are similar obtained from Coats and Redfern method and Arrhenius method and varied from 25 to 29 kJ mol(-1).Öğe A kinetic investigation on the pyrolysis of Seguruk asphaltite(Springer, 2009) Tonbul, Y.; Saydut, A.; Yurdako, K.; Hamamci, C.The pyrolysis of Seguruk asphaltite has been investigated using thermogravimetric analysis at atmospheric pressure between 293 to 1223 K at different linear heating rates of 5, 10 and 20 K min(-1) under nitrogen as ambient gas. There was a two-stage thermal decomposition. Thermal decomposition started around 630 K for stage 1 for the slowest heating rate. On the other hand, for the same heating rate and stage 2, thermal decomposition started around 950 K. These values were shifted to higher temperatures with increasing heating rate. In this study, two different Coats-Redfern methods were applied to thermal degradation of Seguruk asphaltite.Öğe Pyrolysis kinetics of asphaltites determined by thermal analysis(Estonian Acad Publishers, 2006) Tonbul, Y.; Saydut, A.; Hamamci, C.Thermal behavior of Harbul asphaltites (SE Anatolia, Turkey) has been studied using thermogravimetric analysis at atmospheric pressure and with nitrogen as the ambient gas. Asphaltite samples were ground and separated according to their size by sieving. Particle size distribution and chemical composition of asphaltite fractions are given. TG/DTG data of samples demonstrated two stages of mass loss. The first stage, called primary volatization, occurs in the range of 200-600 degrees C, and the second stage, called secondary gasification, in the range of 600-800 degrees C. Kinetic parameters of pyrolysis of asphaltite samples (activation energy, Arrhenius constant and reaction rate constant) were determined separately for both two stages using Coats-Redfern kinetic model.Öğe Pyrolysis of pistachio shell as a biomass(Springer, 2008) Tonbul, Y.There is an increasing concern with the environmental problems associated with the increasing CO2, NOx and SOx emissions resulting from the rising use of fossil fuels. Renewable energy, mainly biomass, can contribute to reduce the fossil fuels consumption. Biomass is a renewable resource with a widespread world distribution. Pistachio is available in large quantities in Gaziantep region in Turkey. Pistachio shell has a good energy potential for exploitation through pyrolysis and gasification. This study deals with the thermal degradation characteristics of in different particle sizes pistachio shell and its kinetics. Thermal degradation analysis have been done by using a thermogravimetric analyzer from room temperature to 800 degrees C in N-2 atmosphere at different heating rates (5, 10, 15 and 20 degrees C min(-1)). TG and DTG curves exhibited two distinct degradation zones. Kinetic parameters were calculated by using Coats-Redfern method and model-free isoconversional Flynn-Wall-Ozawa (FWO) kinetic method.Öğe Thermal behavior and pyrolysis of Avgamasya asphaltite(Estonian Acad Publishers, 2007) Tonbul, Y.; Saydut, A.The pyrolysis and thermal behavior of Avgamasya (SE Anatolia, Turkey) asphaltite was performed using thermogravimetric analysis at atmospheric pressure in dynamic nitrogen atmosphere (30mL min(-1)). Four heating rate profiles (2.5, 5, 10 and 20 K min(-1)) were applied, with a final temperature 1123 K. Two-stage decomposition was observed in the experiments. During the stage 1, when the temperature is lower, only weaker chemical bonds are destroyed and some small gaseous molecules are produced. During the stage 2, when temperature is higher, the cracking is faster and stronger chemical bonds are broken, so that larger molecules decompose into small molecules in the gaseous phase. Kissinger (differential) and Coats-Redfern (integral) methods were applied to thermogravimetric data to obtain kinetic parameters (activation energy and Arrhenius constant).
