20.500.12556/DKUM-99110 Solvotermalna obdelava lignocelulozne biomase z globoko evtektičnimi topili in možnost recikliranja topila Solvothermal treatment of lignocellulosic biomass with deep eutectic solvents and potential solvent recycling V okviru diplomskega dela smo izvedli eksperimente solvotermalne obdelave izbrane vrste lignocelulozne biomase z uporabo različnih vrst globoko evtektičnih topil (angl. deep eutectic solvent-DES) v ustreznih molarnih razmerjih. Kot testni material smo uporabili rožmarinove tropine, ki predstavljajo stranski produkt ekstrakcije karnozola in karnozolne kisline iz rožmarina. Solvotermalno obdelavo smo izvajali pri temperaturi 180 °C, reakcijskem času 3 h, ter razmerju biomasa:topilo (1:8) in razmerju DES:voda (30:70). Nadalje smo preučili možnost večkratne uporabe oziroma recikliranja izbranega topila. Pripravljenim DES topilom smo izmerili pH vrednosti, električne prevodnosti ter preučili njihovo termično obstojnost s termogravimetrično (TGA) analizo. Surovino in trdne produkte solvotermalne obdelave (ogljikov material) rožmarinove pogače smo karakterizirali z analizo kurilnih vrednosti, TGA analizo vsebnosti vlage, hlapnih snovi in pepela, elementno analizo vsebnosti ogljika, vodika, dušika, kisika in žvepla, ter FTIR in TGA-FTIR analizo. Določili smo adsorpcijske lastnosti in pH vrednosti biooglja. V tekočih produktih smo izvedli meritve pH vrednosti in električnih prevodnosti, vsebnosti skupnega dušika, fosforja, amonijevega dušika in organskih kislin, meritve kemijske potrebe po kisiku, antioksidativnosti in akutne toksičnosti ter vsebnosti skupnih fenolov, flavonoidov in skupnih ogljikovih hidratov. S 3D EEM analizo smo karakterizirali raztopljene organske snovi na podlagi njihovih fluorescenčnih lastnosti. Ugotovili smo, da se lastnosti tekočih in trdnih produktov solvotermalne obdelave rožmarinovih tropin bistveno razlikujejo glede na vrsto uporabljenega DES topila in cikel ponovne uporabe procesne tekočine. S termogravimetrično analizo smo dokazali, da se uporabljena DES topila razlikujejo v termični stabilnosti, pri čemer smo ugotovili, da je topilo iz mešanice holin klorida in glukoze najbolj termično stabilno, najmanj termično stabilno pa je iz mešanice holin klorida in citronske kisline. Tekom solvotermalne obdelave smo pridobili biooglja z višjim deležem ogljika ter višjo kurilno vrednostjo, boljšo termično stabilnostjo ter z izboljšanimi adsorpcijskimi kapacitetami. V našem primeru je bilo najboljše DES topilo iz mešanice holin klorida in citronske kisline v razmerju 1:1. V tekočih produktih smo ob ponovni uporabi procesne tekočine zaznali znižanje vsebnosti dušika in amonijevega dušika ter zvišanje vsebnosti skupnega fosforja in organskih kislin, fenolov, ogljikovih hidratov ter akutne toksičnosti. As part of this bachelor's thesis, solvothermal treatment experiments were conducted on a selected lignocellulosic biomass using different deep eutectic solvents (DESs) with appropriate molar ratios. Rosemary pomace, a by-product of the extraction of carnosol and carnosic acid from rosemary, was used as the feedstock. The solvothermal treatment was carried out at 180 °C for 3 h, with a biomass-to-solvent ratio of 1:8 and a DES-to-water ratio of 30:70. In addition, the possibility of reusing and recycling the selected solvent was investigated. The prepared DESs were characterised by measuring their pH and electrical conductivity, while their thermal stability was evaluated using thermogravimetric analysis (TGA). The raw biomass and the solid products of the solvothermal treatment (carbonaceous materials) were characterised by determining their higher heating value (HHV), moisture, volatile matter and ash contents using TGA, and elemental composition (carbon, hydrogen, nitrogen, oxygen and sulfur), as well as by Fourier-transform infrared spectroscopy (FTIR) and TGA-FTIR analysis. Furthermore, the adsorption properties and pH values of the produced biochars were determined. The liquid products were analysed for pH, electrical conductivity, total nitrogen, total phosphorus, ammonium nitrogen, organic acids, chemical oxygen demand (COD), antioxidant activity, acute toxicity, total phenolic content, total flavonoid content and total carbohydrate content. Dissolved organic matter was further characterised by three dimensional excitation-emission matrix (3D EEM) fluorescence spectroscopy. The results showed that the properties of both the liquid and solid products obtained from the solvothermal treatment of rosemary pomace were strongly influenced by the type of DES used and the number of solvent recycling cycles. Thermogravimetric analysis revealed significant differences in the thermal stability of the investigated DESs. The DES composed of choline chloride and glucose exhibited the highest thermal stability, whereas the DES based on choline chloride and citric acid showed the lowest thermal stability. The solvothermal treatment produced biochars with higher carbon content, increased higher heating value, improved thermal stability, and enhanced adsorption capacity compared with the raw biomass. Among the investigated solvents, the DES composed of choline chloride and citric acid in a 1:1 molar ratio proved to be the most effective. Reuse of the process liquid resulted in decreased concentrations of total nitrogen and ammonium nitrogen, while the concentrations of total phosphorus, organic acids, phenolic compounds, carbohydrates, and acute toxicity increased. solvotermalna obdelava lignocelulozna biomasa globoko evtektična topila biooglje recikliranje topila solvothermal treatment lignocellulosic biomass deep eutectic solvents biochar solvent recycling true true false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2026-07-31 18:30:25 2026-09-07 13:46:59 2026-09-08 03:09:20 0000-00-00 00:00:00 2026 0 Maribor 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 UN_Znuderl_Lara_2026.pdf UN_Znuderl_Lara_2026.pdf 1 381A080904167253E9BD09548FD6ADA7 550ab5a46ba7b224877341c5bd9b2b9de1d19d9bfb84172458dd4b834ebe772d 4185118c-a7c5-11f1-b55d-00155d0001be https://dk.um.si/Dokument.php?lang=slv&id=211463 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0