Hidrotermalna i biokatalitička konverzija lignoceluloznih obnovljivih sirovina

master's thesis

• Title (english): Hydrothermal and biocatalytic conversion of lignocellulosic renewable resources
• Author: Ivan Vitez
• Mentor: Božidar Šantek (mentor)
• Granter: University of Zagreb; Faculty of Food Technology and Biotechnology; (Department of Biochemical Engineering); Zagreb
• Defense date and country: 2013-09-26, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Biotechnology

Abstract

Cilj ovog rada je bio optimizirati proces predobrade bukovog drveta kako bi se odstranila hemiceluloza i/ili lignin od celuloznih vlakana, čineći tako vlakna dostupnijim celulolitičkim enzimima. Dva su postupka korištena za ekstrakciju drveta: "Organosolv" i "Liquid Hot Water". Postupci su istraživani pod različitim temperaturama, omjerima između tekuće i krute faze, te međusobno kombinirani. Kao mjera za uspješnost ekstrakcije poslužila je koncentracija glukoze nakon enzimske hidrolize dobivenih vlakana pri koncentraciji od 200 g*L-1, kao i koncentracija potencijalnih inhibitora - furfurala i hidroksimetilfurfurala. Zaključeno je da duže trajanje predobrade drveta u kombinaciji sa većim omjerom tekuće/kruto rezultira većim prinosom glukoze nakon enzimske hidrolize, kao i većim koncentracijama furfurala i hidroksimetilfurfurala u supernatantu nakon ekstrakcije. Nadalje, istraživan je i utjecaj povišenog tlaka na enzimsku hidrolizu kao i stabilizacija Cellic® CTec2 enzima pod povišenim tlakom. Ekonomski potencijal biorafinerija bi se mogao povećati ukoliko bi se postiglo kraće vrijeme enzimske hidrolize pod povišenim tlakom. Rezultati pokazuju da povišeni tlak pozitivno utječe na enzimsku aktivnost a što je uočeno kroz povećanje koncentracije glukoze nakon hidrolize pod povišenim pritiskom.

Abstract (english)

Goal of this study was to optimize pre-treatment conditions for beech wood to remove lignin and/or hemicellulose from cellulosic fibers, thus making them more accessible for cellulolytic enzymes. Focusing on "Organosolv"- and "Liquid Hot Water" extraction, the effect of temperature, extraction time, liquid to solid ratio and the combination of both methods have been investigated. As measurable factors for successful extraction were the glucose concentration after enzymatic hydrolysis of the gained fiber at 200 g*L-1 and concentrations of the potential inhibitors HMF and furfural. It was concluded that longer pretreatment time in combination with higher liquid to solid ratio results in higher glucose yield after enzymatic hydrolysis and higher HMF and furfural concentrations in pretreatment liquor. Furthermore, enzymatic hydrolysis under high pressures, and pressure impact on the stabilization of Cellic® CTec2 enzymes were studied. The economic potential of biorefineries could be considerably improved when hydrolysis time under high pressure will be reduced. The results obtained in these experiments show that high pressure has positive impact on the enzymatic activity and consequently higher sugar concentrations were observed after hydrolysis.

• Keywords: LHW; Organosolv; hidroliza pod povišenim tlakom; biorafinerije; bukovina
• Keywords (english): LHW; Organosolv; high pressure hydrolysis; biorefineries; beech wood
• Language: croatian
• URN:NBN: urn:nbn:hr:159:225057
• Study programme: Title: Bioprocess Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva (magistar/magistra inženjer/inženjerka bioprocesnog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2017-05-04 13:23:14