Recikliranje odpadnih plastičnih mas s hidrotermičnimi postopki : magistrsko delo

Makoter, Kaja

| | SLO | ENG | Cookies and privacy

Bigger font | Smaller font

First page > Show document

Show document

Title:	Recikliranje odpadnih plastičnih mas s hidrotermičnimi postopki : magistrsko delo
Authors:	ID Makoter, Kaja (Author) ID Škerget, Mojca (Mentor) More about this mentor... ID Čolnik, Maja (Comentor)
Files:	MAG_Makoter_Kaja_2023.pdf (4,91 MB) MD5: FF929C10EC3DC97E91492989B7F2F772
Language:	Slovenian
Work type:	Master's thesis/paper
Typology:	2.09 - Master's Thesis
Organization:	FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:	Poliolefini, med katerimi sta najbolj zastopana predstavnika polietilen (PE) in polipropilen (PP), so daleč največji razred sintetičnih polimerov, ki se danes izdelujejo in uporabljajo. Predstavljajo več kot 40 % letno proizvedene plastike, pri čemer se ta količina povečuje in s tem se povečuje tudi letna količina proizvedenih odpadkov. Da bi lahko ta odpadni material pretvorili v uporabne produkte, smo izvedli hidrotermično razgradnjo različnih materialov iz PE in PP z nadkritično vodo. Hidrolizo smo izvedli na osnovnem in recikliranem HDPE pri različni temperaturi (425 °C in 450 °C ) in različnih reakcijskih časih (15 min do 240 min). Pri reakcijskih pogojih 450 °C in 60 min smo degradirali tudi ostale poliolefinske mešanice (metaloceniski LLDPE, dva reciklirana LDPE, dve mešanici granulata (MDPE+LLDPE in LDPE+rLDPE) in foliji iz teh dveh granulatov, folijo PP in vrečko iz LDPE materiala. Kot rezultat smo dobili produkte trdne, plinske, oljne in vodne faze. Trdne faze smo analizirali s Fourierjevo transformacijsko infrardečo spektrskopijo (FTIR), oljne in plinske faze smo analizirali s plinskim kromatografom z masnim spektrometrom (GC-MS) in vodne faze na analizatorju celokupnega ogljika (TOC). Ugotovili smo, da pri kratkih reakcijskih časih nastajajo voski, medtem ko z daljšanjem reakcijskih časov dobimo oljne produkte. V vseh primerih belega ali prozornega granulata in prozorne folije, je nastalo manj kot 1 % ostanka. Več ostanka je nastalo v primeru materialov, ki so vsebovali aditive, torej pri vHDPE (1,57 %), rLDPE2 (1,43 %) in pri vzorcu vrečke (2,97 %). Oljna faza predstavlja tudi glavni produkt razgradnje poliolefinov. Pri vseh vzorcih smo pri 450 °C in 60 min dobili izkoristek oljne faze višji od 89 %. Največji delež oljne faze pri polipropilenskem materialu so predstavljale aromatske spojine (46,77 %), med tem ko pa so v primeru polietilenskih materialov največji delež predstavljali nasičeni alifatski ogljikovodiki (med 50 % in 55 %). Pri osnovnem in recikliranem HDPE smo ugotovili, da je izkoristek plinske faze naraščal z naraščanjem reakcijskega časa (pri osnovnem od 1,32 % do 25,62 % in pri recikliranem od 1,29 % do 29,23 %). Izkoristki ostalih poliolefinskih mešanic pri pogoju 450 °C in 60 min so bili med 4 % in 10 %. Plinske faze so bile o večini sestavljene iz krajših alkanov in alkenov (C1-C6), med katerimi prevladujeta etan in propan. Najvišjo koncentracijo celokupnega ogljika v vodni fazi smo dokazali v primeru osnovnega HDPE materiala (2458 mg/L) pri 450 °C in 60 min. Rezultati te študije kažejo, da nadkritična voda predstavlja dober reakcijski medij za pretvorbo odpadnih poliolefinov v uporabne produkte.
Keywords:	poliolefini, hidrotermična razgradnja, nadkritična voda, GC-MS, FTIR, TOC
Place of publishing:	Maribor
Place of performance:	Maribor
Publisher:	[K. Makoter]
Year of publishing:	2023
Number of pages:	1 spletni vir (1 datoteka PDF (XIII, 52 f.))
PID:	20.500.12556/DKUM-84648
UDC:	66.094.941:678.742.2/.3.028.6(043.2)
COBISS.SI-ID:	185507075
Publication date in DKUM:	14.11.2023
Views:	713
Downloads:	0
Metadata:
Categories:	KTFMB - FKKT
:	Copy citation

Average score:	(0 votes)
Your score:	Voting is allowed only for logged in users.
Share:

Hover the mouse pointer over a document title to show the abstract or click on the title to get all document metadata.

Licences

License:	CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International

Link:	http://creativecommons.org/licenses/by-nc-nd/4.0/
Description:	The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.
Licensing start date:	04.07.2023

Secondary language

Language:	English
Title:	Recycling of waste plastics using hydrothermal processes
Abstract:	Polyolefins, of which polyethylene (PE) and polypropylene (PP) are the most represented, constitute the largest class of synthetic polymers produced and used today. They represent more than 40 % of plastics produced each year, and this amount is increasing, so the amount of waste produced is also increasing. In order to be able to convert these waste materials into useful products, the hydrothermal decomposition of various materials from PE and PP with supercritical water was performed in this study. Hydrolysis was done on virgin and recycled HDPE at different temperatures (425 °C and 450 °C) and different reaction times (15 minutes to 240 minutes). At the reaction conditions of 450 °C and 60 min other polyolefin mixtures (metallocene LLDPE, two recycled LDPE, two granulate mixtures (MDPE+LLDPE and LDPE+rLDPE) and foils made from these two granulates, PP foil and a bag made from LDPE material) were also degraded. As a result, products in the solid, gas, oil and water phases were obtained. The solid phases were analyzed by Fourier-transform infrared spectroscopy (FTIR), the oil and gas phases by gas chromatography–mass spectrometry (GC-MS) and aqueous phases by TOC analyser. It was found that waxes were formed at shorter reaction times, while oily products are obtained at longer reaction times. In all cases of white or transparent granules and transparent film, less than 1 % of residue was formed. More residue occurred in materials containing additives, i.e. vHDPE (1,57 %), rLDPE2 (1,43 %) and the bag sample (2,97 %). The oil phase is the main product of polyolefin decomposition. For all samples, the yield of the oil phase at 450 °C and 60 min was over 89%. Aromatic compounds accounted for the largest proportion of the oil phase from polypropylene material (46,77 %), while saturated aliphatic hydrocarbons accounted for the largest proportion from polyethylene materials (between 50 % and 55 %). It was determined that the yield of the gas phase increased with increasing reaction time for virgin and recycled HDPE (from 1,32 % to 25,62 % for virgin material and from 1,29 % to 29,23 % for recycled HDPE). The yield of the gas phases of other polyolefin mixtures were between 4 % and 10 % at 450 °C and 60 min. The gas phases consisted mainly of shorter alkanes and alkenes (C1-C6), with ethane and propane dominating. The highest concentration of total organic carbon in the water phase was found in the case of virgin HDPE material (2458 mg/L) at 450 °C and 60 min. The results of this study show that supercritical water represents a good reaction medium for the conversion of waste polyolefins into useful products.
Keywords:	polyolefins, hydrothermal degradation, supercritical water, GC-MS, FTIR, TOC

Comments

Leave comment

You must log in to leave a comment.

Comments (0)

0 - 0 / 0

There are no comments!

Back