Hidrotermična razgradnja večslojne odpadne embalaže

magistrsko delo

Mihael Irgolič (Avtor), Mojca Škerget (Mentor), Maja Čolnik (Komentor)

Povzetek

V letu 2020 smo v Sloveniji pridelali več kot milijon ton odpadkov. Skoraj 30 % odpadkov predstavlja odpadna embalaža raznih produktov. Poznamo različne vrste embalaže: papirnato, stekleno, kovinsko, plastično, leseno in večslojno. Večslojni embalaži lahko rečemo tudi sestavljena. Ena izmed najpogosteje uporabljenih in dobro poznanih večslojnih embalaž je tudi tetrapak embalaža. Tetrapak embalaža je sestavljena iz papirja/kartona, polietilena (PE) in aluminija. Problem recikliranja tetrapak embalaže je v tem, da njenih sestavnih delov ni mogoče enostavno ločiti z mehanskimi metodami. Uporaba pod- in nadkritičnih fluidov v različnih kemijskih procesih je vse pogostejša. Zaradi svoje dostopnosti in nizke cene je kot medij za uporabo v nadkritičnih procesih vse pogosteje uporabljena voda. V tem magistrskem delu smo preučevali razgradnjo odpadne tetrapak embalaže s pod- in nadkritično vodo v visokotlačnem in visokotemperaturnem šaržnem reaktorju pri temperaturi od 300 °C do 450 °C ter v časovnem obdobju med 15 in 60 min. Reakcije smo izvajali v eni in v dveh stopnjah. Razmerje odpadni materil/voda je bilo 1 g/10 mL. Nastale produkte v štirih fazah (plinski, vodni, oljni in trdni) smo analizirali s različnimi tehnikami (FTIR, TC, GC/MS, HPLC). Enostopenjsko hidrotermično razgradnjo odpadne tetrapak embalaže smo izvedli pri temperaturi 425 °C oz. 450 °C in reakcijskem času 15 min ali 60 min. Ugotovili smo, da z višanjem temperature in daljšanjem reakcijskega časa narašča izkoristek oljne faze. Najvišji izkoristek oljne faze smo dobili pri temperaturi 450 °C in reakcijskem času 60 min in je znašal 60,7 %. V drugem delu smo izvedli dvostopenjsko hidrotermično razgradnjo odpadne tetrapak embalaže. Prvo stopnjo smo izvedli v podkritični vodi pri temperaturi 250 °C oz. 300 °C in reakcijskem času 30 oz. 60 min. Najvišji izkoristek vodne faze (18,0 %) smo določili pri temperaturi razgradnje 250 °C in reakcijskem času 60 min, najvišji izkoristek oljne faze (35,1 %) pa pri temperaturi razgradnje 300 °C in času 60 min. Drugo stopnjo razgradnje, kjer smo uporabili trdni preostanek iz prve stopnje, smo opravili pri temperaturi 425 oz. 450 °C in reakcijskem času 15 min. Najvišji izkoristek oljne faze po obeh stopnjah skupaj (65,5 %) dobimo pri vzorcu, ki smo ga v prvi stopnji razgradili pri temperaturi 300 °C in reakcijskem času 60 min, v drugi stopnji pa pri temperaturi 450 °C in reakcijskem času 15 min. Oljni fazi smo določili kemijsko sestavo in ugotovili, da je sestavljena iz nasičenih in nenasičenih alifatskih ogljikovodikov, aromatskih spojin, ketonov, alkoholov in amidov. Analizirali smo tudi vodno fazo, v kateri so bili prisotni; glukoza, fruktoza, celobioza, gliceraldehid, anhidrid glukoze, levulinska kislina, furfural in 5-hidroksimetilfurfural. Plinska faza je vsebovala CO2 in ogljikovodike med C1-C6. Po razgradnji tetrapaka je kot trdni preostanek nastal aluminijev prah obdan s tanko plastjo PE.

Ključne besede

hidrotermična razgradnja;večslojna embalaža;tetrapak;odpadna embalaža;nadkritični fluidi;nadkritična voda;magistrske naloge;

Podatki

Jezik:	Slovenski jezik
Leto izida:	2022
Tipologija:	2.09 - Magistrsko delo
Organizacija:	UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik:	[M. Irgolič]
UDK:	[66.04:54-139]:628.4.043(043.2)
COBISS:	115286787
Št. ogledov:	55
Št. prenosov:	0
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	Hydrothermal decomposition of waste multilayer packaging
Sekundarni povzetek:	In 2020, Slovenia produced more than one million tonnes of waste. Packaging of various products accounts for nearly 30% of waste. Various types of packaging include paper, glass, metal, plastic, wood, and multilayer packaging. Multilayer packaging is also known as composite packaging. Tetra Pak® is one of the most widely used and well-known multilayer packaging. Tetra Pak® packaging consists of paper/cardboard, polyethylene (PE) and aluminium. The problem with recycling Tetra Pak® lies in the fact that its components cannot be easily separated by mechanical processing. The use of sub- and supercritical fluids for various chemical processes has become increasingly important method in recent times. Due to its accessibility and low price, water is being more and more frequently used as a medium in supercritical processes. In this master’s thesis we studied the decomposition of waste Tetra Pak® packaging with sub- and supercritical water in a high-pressure and high-temperature batch reactor, at temperatures from 300 °C to 450 °C and a reaction time of 15 to 60 min. Reactions were performed in one and two stages. The ratio material/water was 1 g/10 mL. Degradation products in four phases (gas, aqueous, oil and solid) were analysed by various techniques (FTIR, TC, GC/MS, HPLC). One-stage hydrothermal decomposition of waste Tetra Pak® packaging was performed at a temperature of 425 ° C or 450 ° C and a reaction time of 15 min and 60 minutes. We found out that as the temperature and the reaction time increase, the yield of the oil phase increases. The highest oil yield was obtained at 450 °C and a reaction time of 60 min and it was 60.7 %. In the second part, we performed a two-stage hydrothermal decomposition of waste Tetra Pak®. The first stage was performed in subcritical water at a temperature of 250 °C or 300 °C and a reaction time of 30 or 60 min. The highest yield of the aqueous phase (18.0%) was determined at a decomposition temperature of 250 °C and a reaction time of 60 min, while the highest oil yield (35.1%) was found at a decomposition temperature of 300 °C and a time of 60 min. The second stage of decomposition, where we used the solid residue from the first stage, was performed at a temperature of 425 or 450 °C and a reaction time of 15 min. The highest oil yield after both steps together (65.5%) was obtained for the sample, which was decomposed in the first stage at 300 °C over the period of 60 min, and in the second stage at 450 ° C and over the period of 15 min. The chemical composition of the oil phase was determined and it was found that it is composed of saturated and unsaturated aliphatic hydrocarbons, aromatic compounds, ketones, alcohols and amides. We also analyzed the aqueous phase in which following compounds were present: glucose, fructose, cellubiose, glyceraldehyde, glucose anhydride, levulinic acid, furfural, and 5-hydroxymethylfurfural. The gas phase contained CO2 and hydrocarbons between C1-C6. After decomposition, the solid residue was formed as an aluminium powder, which was surrounded by a thin layer of PE.
Sekundarne ključne besede:	hydrothermal degradation;multilayer packaging;Tetra Pak;waste packaging;supercritical fluids;supercritical water;
Vrsta dela (COBISS):	Magistrsko delo/naloga
Konec prepovedi (OpenAIRE):	2024-07-07
Komentar na gradivo:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Strani:	1 spletni vir (1 datoteka PDF (XIV, 46 f.))
ID:	15324974