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    Determination of pyrolysis properties of sirnak (Avgamasya) asphaltite by thermal analysis methods
    (Taylor & Francis Inc, 2017) Korkmaz, A. Aksogan; Ozbas, K. E.
    In this study, pyrolysis properties of Srnak asphaltite have been determined by thermal analysis methods. According to proximate and elemental analysis results, air-dried sample contains 0.56% moisture, 46.51% ash, 34.02% volatile matter, 18.91% fixed carbon, 42.1% C, 3.57% H, 0.50% N, 5.55% S, and 48.28% O by weight. For the determination of pyrolysis properties of the sample, DTA and TGA of thermal analysis methods have been used. DTA and TGA experiments have been carried out by using approximately 10 mg sample, under 50 ml/min nitrogen gas flow rate, from ambient to 900 degrees C temperature range. To investigate the effects of particle size and heating rate on pyrolysis properties, TGA experiments have been carried out by using three different particle sizes and five different heating rates. By examining the TG/DTG thermograms, three different temperature regions have been found that depend on moisture loss, volatile release, and mineral matter decomposition. Also, by using TG/DTG data of the samples, apparent activation energies and Arrhenius constants were calculated by Arrhenius and Coats-Redfern kinetic models, and the results were compared with each other.
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    Effect of particle size on pyrolysis characteristics of Elbistan lignite
    (Springer, 2008) Ozbas, K. E.
    In this study, the relationship between particle size and pyrolysis characteristics of Elbistan lignite was examined by using the thermogravimetric (TG/DTG) and differential thermal analysis (DTA) techniques. Lignite samples were separated into different size fractions. Experiments were conducted at non-isothermal conditions with a heating rate of 10 degrees C min(-1) under nitrogen atmosphere up to 900 degrees C. Pyrolysis regions, maximum pyrolysis rates and characteristic peak temperatures were determined from TG/DTG curves. Thermogravimetric data were analyzed by a reaction rate model assuming first-order kinetics. Apparent activation energy (E) and Arrhenius constant (A(r)) of pyrolysis reaction of each particle size fraction were evaluated by applying Arrhenius kinetic model. The apparent activation energies in the essential pyrolysis region were calculated as 27.36 and 28.81 kJ mol(-1) for the largest (-2360+2000 mu m) and finest (-38 mu m) particle sizes, respectively.