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KAZAN, DİLEK

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KAZAN

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DİLEK

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Now showing 1 - 4 of 4
  • Publication
    Bioethanol Production From Turkish Hazelnut Husk Process Design and Economic Evaluation
    (SPRINGER, 2019) SAYAR, AHMET ALP; Sayar, Nihat Alpagu; Pinar, Orkun; Kazan, Dilek; Sayar, Ahmet Alp
    The main objective of the current study is to develop and assess the preliminary synthetic design steps of an innovative and unprecedented bioprocess plant converting Turkish hazelnut husk into lignocellulosic ethanol with an emphasis on economic evaluation. Valorization of this agricultural waste would provide a promising economic potential and long-term sustainability with acceptable environmental impact. Preliminary economic evaluations are performed on several scenarios where the effects of changing various process design and operational inputs such as designed plant capacity, evaporation unit operation efficiency, and biocatalyst and nitrogen source prices are simulated. The total capital investment for the base case scenario with an annual throughput of 180,000 metric tons (MT) hazelnut husk is just above USD 111million. The annual operational costs for this case amount to USD 61million. Assuming a sales price of USD 1.50 per kg of bioethanol (achieved via governmental subsidy and tax incentives) the return on investment of the project comes to 12.61% with a 8year payback period. An uncertainty analysis performed on the annual hazelnut husk availability and biocatalyst and nitrogen source price fluctuations establishes a basis for further design of the process taking into account the risk factors associated with the project. The case studies and the uncertainty analysis confirm the fact that production of second generation bioethanol from hazelnut husk in Turkey is a worthwhile endeavor with an economic potential especially with additional social and environmental advantages.
  • PublicationOpen Access
    Assessment of hazelnut husk as a lignocellulosic feedstock for the production of fermentable sugars and lignocellulolytic enzymes
    (SPRINGER HEIDELBERG, 2017-12) SAYAR, AHMET ALP; Pinar, Orkun; Karaosmanoglu, Kubra; Sayar, Nihat Alpagu; Kula, Ceyda; Kazan, Dilek; Sayar, Ahmet Alp
    The present work focuses firstly on the evaluation of the effect of laccase on enzymatic hydrolysis of hazelnut husk which is one of the most abundant lignocellulosic agricultural residues generated in Turkey. In this respect, the co-enzymatic treatment of hazelnut husk by cellulase and laccase, without a conventional pretreatment step is evaluated. Using 2.75 FPU/g substrate (40 g/L substrate) and a ratio of 131 laccase U/FPU achieved the highest reducing sugars concentration. Gas chromatography mass spectrometry confirmed that the hydrolysate was composed of glucose, xylose, mannose, arabinose and galactose. The inclusion of laccase in the enzyme mixture [carboxymethyl cellulase (CMCase) and beta-glucosidase] increased the final glucose content of the reducing sugars from 20 to 50%. Therefore, a very significant increase in glucose content of the final reducing sugars concentration was obtained by laccase addition. Furthermore, the production of cellulases and laccase by Pycnoporus sanguineus DSM 3024 using hazelnut husk as substrate was also investigated. Among the hazelnut husk concentrations tested (1.5, 6, 12, 18 g/L), the highest CMCase concentration was obtained using 12 g/L husk concentration on the 10th day of fermentation. Besides CMCase, P. sanguineus DSM 3024 produced beta-glucosidase and laccase using hazelnut husk as carbon source. In addition to CMCase and b-glucosidase, the highest laccase activity measured was 2240 +/- 98 U/L (8.89 +/- 0.39 U/mg). To the best of our knowledge, this is the first study to report hazelnut husk hydrolysis in the absence of pretreatment procedures.
  • Publication
    A Maltooligosaccharides Producing alpha-Amylase from Bacillus subtilis SDP1 Isolated from Rhizosphere of Acacia cyanophylla Lindley
    (TAYLOR & FRANCIS INC, 2014) OGAN, AYŞE; Ozturk, Hasan Umit; Denizci, Aziz Akin; Ogan, Ayse; Kazan, Dilek
    Maltooligosaccharides producing amylases are required in the food industry, especially in breadmaking. The Bacillus subtilis strain SDP1 amylase hydrolyses starch to produce maltotriose and maltotetraose along with maltose after prolonged reactions of 5 h. Bacillus subtilis strain SDP1 was isolated from the rhizosphere of Acacia cyanophylla Lindley from the cukurova region of Turkey. The highest enzyme production was achieved with soluble starch as the carbon and yeast extract as the nitrogen source and at pH 7.0 and 37 degrees C. Under optimized culture conditions, 68.49 U/mL activity was obtained. SDP1 alpha-amylase had molecular weight of 61 kD. The optimum pH of the enzyme was 7.0 and was highly active at pH ranging from 5.0 to 9.0. The optimum temperature of the crude enzyme was 60 degrees C, and it retained 83% and 74% of its initial activity after 1 h and 2 h incubation periods, respectively, at 50 degrees C. While, Mn+2 has a stimulatory effect on the activity, Ca+2, Mg+2, Na+ did not effect the enzyme activity. Fe+3, Ni+2, Cu+2 and Co+2 had an inhibitory effect on SDP1 amylase activity.
  • Publication
    Biodiesel production from waste oils by using lipase immobilized on hydrotalcite and zeolites
    (ELSEVIER SCIENCE SA, 2007) KAZAN, DİLEK; Yagiz, Funda; Kazan, Dilek; Akin, A. Nilgun
    In this work, hydrotalcite and four different types of zeolites were used as immobilization metarial. The size and type of the zeolite particles did not effect the amount of protein adsorbed. It was found that hydrotalcite is more efficient than zeolites studied. The amount of protein adsorbed (P-g) on hydrotalcite 13 mg/g was higher than that of zeolite as 9 mg/g. The amount of protein adsorbed on hydrotalcite was the highest at pH 8.5 and 4 degrees C. The immobilization of enzyme on hydrotalcite reached steady state after 5 h. Immobilized lipase retained 36% of the initial activity at 45 degrees C and 14% of initial activity at 55 degrees C, after the seventh cycle. Immobilized lipase on hydrotalcite was found to able to catalyse the transesterification of waste cooking oil with methanol to produce methyl esters. Lipase immobilized on zeolites did not show significant yields at the same reaction conditions. (c) 2007 Elsevier B.V. All rights reserved.