20.500.12556/DKUM-93677 Pretvorba lanene pogače v bio-produkte z uporabo pod- in nadkritične vode diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje Conversion of flaxseed cake into bio-products using subcritical and supercritical water Naraščajoče potrebe po trajnostni energiji in zmanjševanju emisij toplogrednih plinov spodbujajo iskanje alternativ fosilnim gorivom. Ena ključnih možnosti je biomasa, ki je obnovljiva, dostopna in energetsko učinkovita. Lanena pogača, stranski produkt pri pridobivanju olja, je bogata s hranili in vlakninami in pogosto ostaja neizkoriščena. Namesto da konča kot odpadek, jo je zaradi lignocelulozne sestave mogoče učinkovito predelati v uporabne bio-produkte. Med naprednimi metodami predelave izstopa uporaba pod- in nadkritične vode, s katero lahko pridobimo bio-olje, plin in oglje. Razgradnjo lanene pogače s pod- in nadkritično vodo smo izvedli pri treh različnih temperaturah (300 °C, 350 °C in 400 °C) ter štirih časih obdelave (30 min, 60 min, 90 min in 120 min). V vseh eksperimentih smo kot produkt pridobili trdno, oljno, vodno in plinsko fazo, pri čemer je v vseh prevladovala oljna faza. Najvišji izkoristek oljne faze smo dosegli pri 300 °C in 30 min, in sicer kar 72,3 %. Z višanjem temperature in podaljševanjem časa se je njen izkoristek postopoma zniževal in dosegel najnižjo vrednost pri 400 °C in 120 min (50 %), medtem ko sta deleža trdne in vodne faze upadala, trdna faza z 10 % na 3 %, vodna pa s 13 % na 4 %. Nasprotno je izkoristek plinske faze pričakovano naraščal in pri najvišji temperaturi 400 °C in najdaljšem času 120 min dosegel maksimalno vrednost (42,5 %). Kemijsko sestavo oljne in plinske faze smo analizirali z metodo GC/MS. Plinske mešanice so v glavnem vsebovale CO₂ in ogljikovodike od C1-C6. V oljnih fazah pa smo identificirali alkane, alkene, aromate, ketone, estre, kisline, amide ter druge dušikove spojine. Največ amidov je nastalo pri 300 °C, medtem ko se je z višanjem temperature koncentracija aromatov in ketonov povečevala. Oljne faze so imele zgornje kurilne vrednosti med 24 do 32 MJ/kg. V vodnih fazah smo z analizatorjem TOC določili koncentracijo skupnega ogljika, z uporabo HPLC pa zaznali tudi prisotnost furfuralov. Pridobljeni podatki celovite analize sekundarnih produktov, nastalih pri hidrotermični razgradnji lanene pogače, predstavljajo pomemben korak k razvoju učinkovitih alternativnih biogoriv. The growing demand for sustainable energy and the need to reduce greenhouse gas emissions are driving the search for alternatives to fossil fuels. One of the key options is biomass, which is renewable, accessible, and energy-efficient. Flaxseed cake, a by-product of oil extraction, is rich in nutrients and fiber but often remains underutilized. Instead of ending up as waste, it can be efficiently converted into valuable bio-products due to its lignocellulosic composition. Among advanced conversion methods, the use of subcritical and supercritical water stands out, enabling the production of bio-oil, gas, and biochar. The decomposition of flaxseed cake using sub- and supercritical water was carried out at three different temperatures (300 °C, 350 °C, and 400 °C) and four different reaction times (30 min, 60 min, 90 min, and 120 min). Solid, oil, aqueous and gaseous phases were obtained in all experiments, with the oil phase predominat in each case. The highest oil yield (72.3%) was achieved at 300 °C for 30 minutes. As the temperature and reaction time increased, the oil yield gradually decreased, reaching the lowest value of 50% at 400 °C and 120 min, while the yields of the solid and aqueous phases decreased from 10% to 3% and from 13% to 4%, respectively. In contrast, the yield of the gas phase increased with temperature and time, reaching a maximum value of 42.5% at 400 °C and 120 min.The chemical composition of the oily and gaseous phases was analyzed using the GC/MS method. The gaseous mixtures mainly contained CO₂ and C1–C6 hydrocarbons. In the oil phases, we identified alkanes, alkenes, aromatics, ketones, esters, acids, amides, and other nitrogen-containing compounds. The highest concentration of amides was found at 300 °C, while the concentrations of aromatics and ketones increased with temperature. The higher heating values (HHV) of the oil phases were between 24 to 32 MJ/kg. In the aqueous phases, the total carbon content was determined using a TOC analyzer, and the presence of furfurals was confirmed by HPLC analysis. The obtained data from the comprehensive analysis of the secondary products generated during the hydrothermal degradation of flaxseed cake represent an important step towards the development of efficient alternative biofuels. lignocelulozna biomasa lanena pogača pod- in nadkritična voda kemijska pretvorba biogoriva lignocellulosic biomass flaxseed cake subcritical and supercritical water chemical conversion biofuels true true false [A. Šket] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-07-13 13:16:53 2025-09-18 11:33:43 2025-09-27 03:36:30 0000-00-00 00:00:00 2025 0 Maribor 0 Maribor 1 spletni vir (1 datoteka PDF (VIII, 29 f.)) 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 604.4:662.6(043.2) 250676227 VS_Sket_Anja_2025.pdf VS_Sket_Anja_2025.pdf 1 65821D7A5B3F92474E2A6920BEB695CC b537fa37342a673a4e773277800df2a35a49c3bd0bc7d5c4b608698eb80eb93a dc87db43-8f45-11f0-886e-00155d000105 https://dk.um.si/Dokument.php?lang=slv&id=198277 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0