Hidrotermično uplinjanje lignocelulozne biomase

diplomsko delo univerzitetnega študijskega programa

Chiara Železnik (Author), Mojca Škerget (Mentor), Maja Čolnik (Co-mentor)

Abstract

Prekomerno izčrpavanje in zanašanje na energijo, pridobljeno iz fosilnih goriv, je privedlo do globalnih podnebnih sprememb in onesnaževanja ozračja. S tem namenom so največje industrije začele z uveljavljanjem okolju bolj prijaznih praks, ki bi hkrati zmanjšale odvisnost od neobnovljivih virov energije, ki so v pomanjkanju. Lignocelulozna biomasa je najobsežnejša in biološko obnovljiva biomasa na Zemlji, ki kaže velike potenciale za zamenjavo fosilnih goriv kot primarni vir energije. Sestavljena je pretežno iz celuloze (40–60 %), hemiceluloze (20–40 %) in lignina (10–24 %), ki predstavljajo bogat vir surovin za proizvodnjo biogoriv. Raziskave na področju lignocelulozne biomase se osredotočajo na iskanje alternativnih postopkov, s katerimi bi lahko lignocelulozno biomaso pretvorili v vredne kemikalije. V okviru diplomske naloge smo izvajali reakcije hidrotermičnega uplinjanja slivovega lesa v pod- in nadkritični vodi, pri temperaturah 350 °C in 400 °C, brez ali v prisotnosti štirih različnih katalizatorjev (GeO2, Ni/SiO2-Al2O3, bentonit, zeolit). Dobili smo produkte v plinski, oljni, vodni in trdni fazi. Na podlagi izkoristkov posameznih faz in FTIR analiz trdnih ostankov smo ugotovili, da je do večje razgradnje slivovega lesa prišlo pri višjih temperaturah, kjer smo dobili višje izkoristke plinske in oljne faze ter nižje izkoristke trdne faze. Katalizator Ni/SiO2-Al2O3 je povzročil popolno razgradnjo slivovega lesa, z le 0,49 % izkoristka trdne faze. Ugotovili smo, da so vse plinske mešanice vsebovale H2, CO2 ter ogljikovodike C1-C6, od katerih je nastalo največ H2 in CH4. Najvišjo koncentracijo (glede na površino vrha %) vodika (80,7 %) smo določili s katalizatorjem Ni/SiO2-Al2O3 pri 400 °C. V oljnih fazah smo določili prisotnost alkanov, cikličnih spojin, aromatskih spojin, ketonov in kislin, med katerimi je nastalo največ ketonov in aromatskih spojin. HPLC analize vodnih faz so pokazale prisotnost furfuralov, med katerimi so bile koncentracije 5–MF najvišje. Najnižjo koncentracijo skupnega organskega ogljika (5,5 g/L) v vodni fazi pa smo določili pri reakciji z Ni/SiO2-Al2O3 pri 400 °C.

Keywords

lignocelulozna biomasa;hidrotermično uplinjanje;podkritična voda;nadkritična voda;zelene tehnologije;recikliranje odpadkov;diplomske naloge;

Data

Language:	Slovenian
Year of publishing:	2023
Typology:	2.11 - Undergraduate Thesis
Organization:	UM FKKT - Faculty of Chemistry and Chemical Engineering
UDC:	662.7:[604.4:631.571](043.2)
COBISS:	165184259
Views:	24
Downloads:	0
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary title:	Hydrothermal gasification of lignocellulosic biomass
Secondary abstract:	Over-exploitation and over-reliance on fossil fuel energy has led to global climate change and atmospheric pollution. To this end, major industries have started to adopt more environmentally friendly practices that would at the same time reduce their dependence on non-renewable energy sources, which are in short supply. Lignocellulosic biomass is the most abundant and bio-renewable biomass on Earth, showing great potential to replace fossil fuels as a primary energy source. It consists mainly of cellulose (40-60%), hemicellulose (20-40%) and lignin (10-24%), which constitute a rich source of raw materials for biofuel production. Research on lignocellulosic biomass is focusing on finding alternative processes that can convert lignocellulosic biomass into valuable chemicals. In the framework of the thesis, hydrothermal gasification reactions of plum wood were carried out in sub- and supercritical water, at temperatures of 350 °C and 400 °C, without or in the presence of four different catalysts (GeO2, Ni/SiO2-Al2O3, bentonite, zeolite). The products obtained were in gas, oil, aqueous and solid phases. Based on the yields of the individual phases and FTIR analyses of the solid residues, it was found that the higher decomposition of plum wood occurred at higher temperatures, where higher yields of the gas and oil phases and lower yields of the solid phase were obtained. The Ni/SiO2-Al2O3 catalyst resulted in a complete decomposition of the plum wood, with only 0,49 % solid phase yield. All gas mixtures were found to contain H2, CO2 and C1-C6 hydrocarbons, of which H2 and CH4 were the most abundant. The highest concentration (in % of peak area) of hydrogen (80,7 %) was determined with the Ni/SiO2-Al2O3 catalyst at 400 °C. The presence of alkanes, cyclic compounds, aromatic compounds, ketones and acids was determined in the oil phases, with ketones and aromatic compounds being the most abundant. HPLC analyses of the aqueous phases showed the presence of furfurals, among which 5–MF was the most abundant. However, the lowest concentration of total organic carbon (5,5 g/L) in the aqueous phase was determined in the reaction with Ni/SiO2-Al2O3 at 400 °C.
Secondary keywords:	lignocellulosic biomass;hydrothermal gasification;subcritical water;supercritical water;green technologies;waste recycling;
Type (COBISS):	Bachelor thesis/paper
Embargo end date (OpenAIRE):	2026-09-01
Thesis comment:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Pages:	1 spletni vir (1 datoteka PDF (X, 43 f.))
ID:	19829038