İlknur Demiral
Eskişehir Osmangazi University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by İlknur Demiral.
Bioresource Technology | 2011
İlknur Demiral; Emine Aslı Ayan
In this study, pyrolysis of grape bagasse was investigated with the aim to study the product distribution and their chemical compositions and to identify optimum process conditions for maximizing the bio-oil yield. Particular investigated process variables were temperature (350-600°C), heating rate (10-50°C/min) and nitrogen gas flow rate (50-200 cm(3)/min). The maximum oil yield of 27.60% was obtained at the final pyrolysis temperature of 550°C, sweeping gas flow rate of 100 cm(3)/min and heating rate of 50°C/min in a fixed-bed reactor. The elemental analysis and heating value of the bio-oils were determined, and then the chemical composition of the bio-oil was investigated using chromatographic and spectroscopic techniques such as column chromatography, (1)H NMR and FTIR. The fuel properties of the bio-oil such as flash point, viscosity and density were also determined. The bio-oils obtained from grape bagasse were presented as an environmentally friendly feedstock candidate for bio-fuels.
Bioresource Technology | 2008
İlknur Demiral; Sevgi Şensöz
Pyrolysis of olive and hazelnut bagasse biomass samples with two selected catalysts, namely activated alumina and sodium feldspar, have been conducted in a fixed-bed reactor. Experiments were carried out under certain pyrolysis conditions in a fixed-bed Heinze reactor. The catalyst was mixed with feedstock in different percentages. The effects of catalysts and their ratio (10%, 20%, 30% and 40% w/w) on the pyrolysis product yields were investigated and the results were compared with the results of experiments performed without catalyst under the same conditions. The maximum bio-oil yields for the bio-oils obtained from pyrolysis of olive bagasse were found as 37.07% and 36.67% on using activated alumina and sodium feldspar as catalysts, respectively, while these values were 27.64% and 31.68%, respectively, for the bio-oils from hazelnut bagasse. The oxygen contents of the bio-oils were also markedly reduced while the yield of bio-oil was reduced by the use of catalysts. The pyrolysis oils were examined using some spectroscopic and chromatographic analysis techniques. The results were compared with the petroleum fractions and the possibility of being a potential source of bio-oils was investigated.
Chemical Engineering Communications | 2008
İlknur Demiral; Nurdilek Gülmezoğlu Atilgan; Sevgi Şensöz
Soft shell of pistachio (Pistacia vera L.) pyrolysis experiments were performed in a fixed-bed reactor to produce bio-oil. The effects of temperature, heating rate, and sweep gas (N2) flow rates on the yields and compositions of products were investigated. Pyrolysis runs were performed using reactor temperatures between 350° and 500°C with heating rates of 15° and 50°C/min. Nitrogen flow rates varied between 50 and 200 cm3/min and mean particle size was 0.8 mm. The maximum bio-oil yield of 33.18% was obtained in a nitrogen atmosphere with nitrogen flow rate of 150 cm3/min and at 450°C pyrolysis temperature with a heating rate of 50°C/min.The elemental analysis and gross heating value of the bio-oil were determined, and then the chemical composition of the bio-oil was investigated using chromatographic and spectroscopic techniques. The chemical characterization has shown that the bio-oil obtained from soft shell of pistachio can be used as a renewable fuel and chemical feedstock.
Chemical Engineering Journal | 2008
Hakan Demiral; İlknur Demiral; Fatma Tümsek; Belgin Karabacakoğlu
Bioresource Technology | 2006
Sevgi Şensöz; İlknur Demiral; Hasan Ferdi Gerçel
Chemical Engineering Research & Design | 2011
Hakan Demiral; İlknur Demiral; Belgin Karabacakoğlu; Fatma Tümsek
Biomass & Bioenergy | 2012
İlknur Demiral; Alper Eryazıcı; Sevgi Şensöz
Surface and Interface Analysis | 2008
Hakan Demiral; İlknur Demiral; Fatma Tümsek; Belgin Karabacakoğlu
Journal of Analytical and Applied Pyrolysis | 2014
İlknur Demiral; Şerife Çemrek Kul
Surface and Interface Analysis | 2008
Hakan Demiral; İlknur Demiral