Primerjava različnih vrednotenj zgradbe lignina kot opredelitve kinetičnih skupkov

Vidmar, Monika (author), Likozar, Blaž (mentor), Kralj Cigić, Irena (co-mentor)

Težava današnje družbe je pridobivanje čiste in cenovno ugodne energije. Med potencialnimi vir energije je tudi biomasa. Glavna komponenta le-te je tudi lignin, iz katerega se lahko poleg goriva pridobiva še kemikalije, ki so veliko v uporabi. Da lahko lignin uporabimo, pa je potrebno ohraniti večji delež etrskih vezi, med katerimi prevladuje β-O-4 vez. V magistrskem delu sem s pomočjo modelne spojine preiskovala cepitev β-O-4 vezi, pri različnih pogojih, ki se uporabljajo pri organosolv postopku izolacije lignina. Preiskovala sem mehanizem cepitve etrske vezi in stranske reakcije, katerih produkte sem analizirala z različnimi tehnikami, kot so to na primer FTIR, GC-MS, UV-VIS spektroskopija in 1H NMR. Nato sem z izbranimi pogoji reakcije preučevala tudi izolacijo lignina iz biomase. Spremljala sem cepitev etrskih vezi s pomočjo FTIR, SEC, 2D HSQC, 31P NMR in UV-VIS spektroskopije. Rezultate sem primerjala z reakcijo modelne spojine 2-fenoksi-1-feniletanola in potrdila, da je bilo pri nižji temperaturi ohranjenih več etrskih vezi. Poiskala sem tudi možne korelacije med analiznimi tehnikami, ki bi bile uporabne pri izdelavi mikrokinetičnega modela za nadaljnje raziskovanje.

• Language: Slovenian
• Keywords: Organosolv lignin, modelna spojina, β-O-4
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2023
• PID: 20.500.12556/RUL-146401
• COBISS.SI-ID: 158642435
• Publication date in RUL: 31.05.2023

Secondary language

• Language: English
• Title: Comparison of different structural evaluations of lignin as determination of kinetic clusters

Abstract

The problems of today's society include obtaining clean and affordable energy. Among the potential source of energy is also biomass. The main component of biomass is also lignin, which is used to produce fuel as well as chemicals that are widely used. For the efficient use of lignin, it is necessary to maintain a greater proportion of ether bonds, in which β-O-4 bond predominates. In my master's thesis, I investigated the cleavage of β-O-4 bond by using a model molecule under various conditions used in the organosolv isolation process of lignin. I studied the mechanism of ether bond cleavage and side reactions, the products of which were analysed using various techniques such as FTIR, GC-MS, UV-VIS spectroscopy, and 1H NMR. I then studied the isolation of lignin from biomass using the selected reaction conditions. I monitored the cleavage of ether bonds using FTIR, SEC, 2D HSQC, 31P NMR, and UV-VIS spectroscopy. I compared the results with the reaction of the model molecule 2-phenoxy-1-phenylethanol and confirmed that at lower temperatures, more ether bonds were preserved. I also searched for possible correlations between analytical techniques that could be useful in developing a microkinetic model for further research.

• Keywords: Organosolv lignin, model molecule, β-O-4