Bitkisel atık yağların karakterizasyonu ve biyodizel üretiminde değerlendirilmesi
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Date
2010-01-11
Authors
Aybastıer, Önder
Journal Title
Journal ISSN
Volume Title
Publisher
Uludağ Üniversitesi
Abstract
Thermomyces lanuginosus lipaz enzimi mikroporoz stiren-divinilbenzen- poliglutaraldehit (STR-DVB-PGA) polimerine kovalent olarak immobilize edilmiştir. Merkezi kompozit dizayn ile immobilizasyon üzerine enzim konsantrasyonunun (% 4-16 v/v), tampon pH'nın (6,0-8,0), tampon konsantrasyonunun (20-100 mM), immobilizasyon süresinin (8-40 saat) etkisi incelenmiş ve etkili faktörler optimize edilmiştir. Enzim konsantrasyonu, pH ve tampon konsantrasyonunun spesifik aktivite üzerinde etkili olan önemli faktörler olduğunu bulunmuştur. Optimum koşullardaki tahmini spesifik aktivite 8.78 ?mol pNP/mg enzim.dk olarak hesaplanmış, deneysel spesifik aktivite ise 8,41 ?mol pNP/mg enzim.dk olarak belirlenmiştir. Metanol ve t-bütonolün immobilize lipazın spresifik aktivitesi üzerine etkisi incelenmiştir. İmmobilize lipazın aktivitesi t-bütanolde hemen hemen değişmezken, metanolde büyük oranda azalmaktadır. Çalışmanın ikinci aşamasında çapraz bağlayıcı olarak glutaraldehit kullanılarak kitosan küreler hazırlanmıştır. Candida antarctica A lipaz enzimi kitosan küreler üzerine kovalent olarak immobilize edilmiştir. Bu küreler üzerine yapılan immobilizasyonda en yüksek spesifik aktivite, % 12 (v/v) enzim konsantrasyonunda ve 24 saat immobilizasyon süresinde elde edilmiştir. Optimum koşullarda enzim immobilize edilen STR-DVB-PGA polimeri ve kitosan küreleri kullanılarak ön işlem uygulanmamış atık kanola yağından biyodizel üretilmiştir. Her iki destek maddesi kullanılarak üretilen biyodizel verimleri sırası ile % 85,95 ve % 59,32 dir. STR-DVB-PGA destek maddesi ile daha yüksek oranda biyodizel elde edildiği görülmüştür.
Lipase from Thermomyces lanuginosus was immobilized by covalent binding on a novel microporous styrene-divinylbenzene-polyglutaraldehyde copolymer (STY-DVB-PGA). The central composite design was employed to evaluate the effects of enzyme concentration (4-16 %v/v), buffer pH (6.0-8.0), buffer concentration (20-100 mM) and immobilization time (8-40 h) on the specific activity, and significant parameters were optimized. The results indicated that enzyme concentration, pH and buffer concentration were the significant factors on the specific activity of immobilized lipase. The predicted specific activity was 8.78 ?mol pNP/mg enzyme.min under the optimal conditions and the subsequent verification experiment with specific activity of 8.41 ?mol pNP/mg enzyme.min confirmed the validity of the predicted model. The effect of methanol and tert-butanol on the specific activity of immobilized lipase was investigated. The immobilized lipase was almost stable in tert-butanol whereas it lost most of its activity in methanol. In second part of study, chitosan beads were prepared by using a crosslinking agent as glutaraldehyde. Lipase from Candida antarctica A was immobilized by covalent binding on chitosan beads. The maximum specific activity was found as enzyme concentration of 12 % (v/v) and immobilization time of 24 hours. Production of biodiesel was performed with STY-DVB-PGA polymer and chitosan beads as support materials using waste canola oil. The yields of biodiesel were 85.95 % and 59.32 %, respectively. It was observed that STY-DVB-PGA support material provided higher biodiesel yield.
Lipase from Thermomyces lanuginosus was immobilized by covalent binding on a novel microporous styrene-divinylbenzene-polyglutaraldehyde copolymer (STY-DVB-PGA). The central composite design was employed to evaluate the effects of enzyme concentration (4-16 %v/v), buffer pH (6.0-8.0), buffer concentration (20-100 mM) and immobilization time (8-40 h) on the specific activity, and significant parameters were optimized. The results indicated that enzyme concentration, pH and buffer concentration were the significant factors on the specific activity of immobilized lipase. The predicted specific activity was 8.78 ?mol pNP/mg enzyme.min under the optimal conditions and the subsequent verification experiment with specific activity of 8.41 ?mol pNP/mg enzyme.min confirmed the validity of the predicted model. The effect of methanol and tert-butanol on the specific activity of immobilized lipase was investigated. The immobilized lipase was almost stable in tert-butanol whereas it lost most of its activity in methanol. In second part of study, chitosan beads were prepared by using a crosslinking agent as glutaraldehyde. Lipase from Candida antarctica A was immobilized by covalent binding on chitosan beads. The maximum specific activity was found as enzyme concentration of 12 % (v/v) and immobilization time of 24 hours. Production of biodiesel was performed with STY-DVB-PGA polymer and chitosan beads as support materials using waste canola oil. The yields of biodiesel were 85.95 % and 59.32 %, respectively. It was observed that STY-DVB-PGA support material provided higher biodiesel yield.
Description
Keywords
Merkezi kompozit dizayn, Lipaz, İmmobilizasyon, STR-DVB-PGA, Kitosan, Atık kanola yağı, Biyodizel, Central composite design, Lipase, Immobilization, Chitosan, Waste canola oil, Biodiesel
Citation
Aybastıer, Ö. (2010). Bitkisel atık yağların karakterizasyonu ve biyodizel üretiminde değerlendirilmesi. Yayınlanmamış yüksek lisans tezi. Uludağ Üniversitesi Fen Bilimleri Enstitüsü.