magistrsko delo
Povzetek
Plastični odpadki predstavljajo velik problem za okolje, saj se velike količine proizvedene plastike ob koncu življenjske dobe znajdejo na odlagališčih, kjer onesnažujejo tla, vode in zrak. Poseben izziv predstavljajo termoseti, ki jih je zaradi njihovih lastnosti težje reciklirati v primerjavi s termoplasti. Melaminske smole spadajo med termosete in so znane predvsem po svoji toplotni odpornosti in stabilni strukturi. Zaradi teh lastnosti in predvsem zaradi trenutnega neznanja glede možnosti recikliranja, svoj življenjski cikel pogosto končajo na odlagališčih. Encimski in hidrotermični procesi so obetavne metode za možno recikliranje in ponovno uporabo termosetov. Oboji procesi predstavljajo okolju prijazne metode za pretvorbo plastičnih odpadkov v uporabne materiale. Encimski procesi povzročijo razgradnjo materiala pod blagimi okolju prijaznimi pogoji, hidrotermični procesi pa uporabljajo vodo pri visoki temperaturi in tlaku.
Tekom magistrskega dela smo preučili encimsko in hidrotermično razgradnjo vlaken melaminske eterificirane smole (MER). Encimsko razgradnjo smo izvedli z uporabo različnih prebavnih encimov, hidrotermično razgradnjo pa pri različnih temperaturah razgradnje: 200, 250, 275, 300 in 350 °C. V vodni fazi smo s pomočjo kivetnih testov analizirali vsebnosti formaldehida, organskih kislin, skupnega dušika in amonijaka. Pri hidrotermični razgradnji smo dodatno analizirali še trdno in plinasto fazo. Glede na podatke pridobljene iz eksperimentalnega dela pri različnih temperaturah hidrotermične razgradnje smo nadalje analizirali okoljske odtise s pomočjo programske opreme OpenLCA in različnih baz podatkov. Ocenili smo odtis toplogrednih plinov (GHG), dušika, fosforja, energetski in ekološki odtis ter potencial strupenosti za človeka. Rezultati kažejo, da je razgradnja pri 200 °C povzročila najmanjši vpliv na okolje, vendar pa so bile največje količine sekundarnih spojin pridobljene pri temperaturi razgradnje 300 °C.
Ključne besede
vlakna iz melaminskih eterificiranih smol;MER vlakna;encimska razgradnja;hidrotermična razgradnja;identifikacija nevarnosti;HAZOP;analiza življenjskega cikla;LCA;magistrske naloge;
Podatki
Jezik: |
Slovenski jezik |
Leto izida: |
2022 |
Tipologija: |
2.09 - Magistrsko delo |
Organizacija: |
UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo |
Založnik: |
[T. Vidovič] |
UDK: |
628.477.6:678.652(043.2) |
COBISS: |
112547075
|
Št. ogledov: |
101 |
Št. prenosov: |
15 |
Ocena: |
0 (0 glasov) |
Metapodatki: |
|
Ostali podatki
Sekundarni jezik: |
Angleški jezik |
Sekundarni naslov: |
Hazars identification and environmental impact assessment of hydrothermal degradation of melamine etherified resin (MER) fibers |
Sekundarni povzetek: |
Plastic waste poses a major problem for the environment, as large quantities of produced plastic end up in landfills at the end of their lifetime, where they pollute soil, water and air. Particular challenge present thermoset materials which are more difficult to recycle compared to thermoplastics. Melamine resins are thermosets and are known mainly for their heat resistance and stable structure. Because of these properties, and especially because of current lack of knowledge regarding their recyclability, they often end their life cycle in landfills. Enzymatic and hydrothermal processes are promising methods for recycling and reuse of thermosets. Both processes are environmentally friendly methods for converting plastic waste into usable materials. Enzymatic processes cause the decomposition of the material under mild environmentally friendly conditions, while hydrothermal processes use water at high temperature and pressure.
During the master's thesis, the enzymatic and hydrothermal degradation of melamine etherified resin (MER) fibers were studied. Enzymatic degradation was performed using different digestive enzymes, and the hydrothermal degradation was performed at different degradation temperatures: 200, 250, 275, 300 and 350 °C. In the aqueous phase, the contents of formaldehyde, organic acids, total nitrogen and ammonium were analyzed using tube tests. In case of hydrothermal decomposition, the solid and gas phase were additionally analyzed. Based on the data obtained from the experimental work at different temperatures of hydrothermal decomposition, the environmental footprints were further analyzed using OpenLCA software and various databases. The greenhouse gas (GHG), nitrogen, phosphorus, energy and ecological footprints were assessed together with the human toxicity potential. The results show that degradation at 200 °C caused the least impact on the environment, however the largest amounts of secondary compounds were obtained at a decomposition temperature of 300 °C |
Sekundarne ključne besede: |
melamine etherified resin fibers (MER fibers);enzymatic degradation;hydrothermal degradation;hazard identification;HAZOP;life cycle analysis (LCA); |
Vrsta dela (COBISS): |
Magistrsko delo/naloga |
Komentar na gradivo: |
Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo |
Strani: |
1 spletni vir (1 datoteka PDF (XI, 77 f.)) |
ID: |
15334968 |