Pretvorba lignina v uporabne kemikalije

diplomsko delo

Luka Gorenčič (Author), Jernej Iskra (Mentor)

Abstract

V diplomskem delu sem raziskal in predstavil osnovne lastnosti in pretvorbe lignina v uporabne produkte in kemikalije. Danes se zaradi problematike z energetsko krizo in podnebnimi spremembami študije vse bolj usmerjajo v proizvodnjo produktov z dodano vrednostjo, raznih kemikalij in goriv, ki so pridobljeni iz obnovljivih virov. Eden izmed najbolj pogostih je lignocelulozna biomasa. Sestavljena je iz treh večjih komponent, in sicer aromatskih makromolekul (lignina) in polisaharidov (celuloza in hemiceluloza). Lignin je razvejan aromatski polimer, ki je zelo kompleksen in je poleg celuloze najbolj pomembna in razširjena organska snov v rastlinskem svetu. V osnovi lignin služi kot strukturna komponenta s hidrofobno zaščitno plastjo v rastlinski celični steni ter skupaj povezuje celulozo in hemicelulozo. Tradicionalno se lignin izolira iz lignocelulozne biomase pri frakcioniranju v industriji celuloze ter papirja in pri fermentaciji v biorafinerijah, kjer se večinoma tretira kot stranski in odvečni produkt, a se vse bolj izkazuje, da bo lignin lahko nadomestil fosilne surovine in se tako uporabil v trajnostnih proizvodnjah goriv, kemikalij in materialov. Njegova kompleksna tridimenzionalna amorfna struktura, visoke molekulske mase in strukturne naključnosti predstavljajo velik izziv pri njegovi izolaciji iz lignocelulozne biomase in nadaljnji pretvorbi do uporabnih produktov, zato so potrebni različni postopki predobdelave. Uporabljajo se različne delignifikacijske metode, kot so postopek kraft, organosolv postopek, sulfitni postopek, soda proces, parna eksplozija in reduktivno katalitično frakcioniranje. Pri teh metodah frakcioniranja lignoceluloze se spremeni kemijska struktura nativnega lignina, kar zaenkrat predstavlja še velik izziv. Za dosego boljšega lignina in pridobitev kemikalij z dodanimi vrednostmi so potrebne nadaljnje metode pretvorbe, ki zahtevajo različne pogoje delovanja. V diplomskem delu so predstavljene osnovne lastnosti lignina in njegova pot pretvorbe od lignocelulozne biomase s postopki izolacije, karakterizacije, predelave in do na koncu uporabnih kemikalij z dodanimi vrednostmi.

Keywords

lignocelulozna biomasa;delignifikacija;industrija lignina;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2022
Typology:	2.11 - Undergraduate Thesis
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher:	[L. Gorenčič]
UDC:	547.458.84(043.2)
COBISS:	116113155
Views:	91
Downloads:	26
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Conversion of lignin into valuable chemicals
Secondary abstract:	In my thesis, I studied and presented the basic properties and conversion of lignin into useful products and chemicals. Nowadays, due to the energy crisis and climate change, studies are increasingly focusing on the production of value-added products, various chemicals and fuels derived from renewable sources. One of the most common sources is lignocellulosic biomass. It consists of three main components, namely aromatic macromolecules (lignin) and polysaccharides (cellulose and hemicellulose). Lignin is a branched aromatic polymer that is very complex and, along with cellulose, is the most important and widespread organic substance on the plant world. Lignin serves as a structural component with a hydrophobic protective layer in the plant cell wall and binds cellulose and hemicellulose together. Traditionally lignin is isolated from lignocellulosic biomass during fractionation in the pulp and paper industry and during fermentation in biorefineries where it is mostly processed as a by-product and surplus in industry, but it is increasingly being shown that lignin will be able to replace fossil raw materials and thus can be used in the sustainable production of fuels, chemicals and materials. Its complex three-dimensional amorphous structure, high molecular weights and structural randomness pose a major challenge for its isolation from lignocellulosic biomass and further conversion to useful products, so different pre-treatment processes are required. Various delignification methods are used, such as kraft process, organosolv process, sulfite process, soda process, steam explosion and reductive catalytic fractionation. These methods of lignocellulose fractionation change the chemical structure of native lignin, which is still a major challenge in production of lignin value-added chemicals. Further conversion methods are required to achieve better lignin and to obtain value-added chemicals that require different operating conditions. My thesis presents the basic properties of lignin and its conversion path from lignocellulosic biomass with processes of its isolation, characterization, processing and finally to useful chemicals with added value.
Secondary keywords:	lignin industry;lignocellulosic biomass;delignification;Lignin;Univerzitetna in visokošolska dela;
Type (COBISS):	Bachelor thesis/paper
Study programme:	1000374
Embargo end date (OpenAIRE):	1970-01-01
Thesis comment:	Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Pages:	38 str.
ID:	15776731