Hidrotermična degradacija odpadne embalaže iz polipropilena

diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje

Kristina Kranjčec (Avtor), Mojca Škerget (Mentor), Maja Čolnik (Komentor)

Povzetek

Namen in cilj diplomskega dela je bil raziskati hidrotermično degaradacijo odpadne embalaže iz polipropilena (PP) s pomočjo superkritične vode ter določiti nastale produkte. Izvedena je bila primerjava pisanega in brezbarvnega PP. Proučevali smo vpliv procesnih parametrov, kot so tlak, temperatura, razmerje voda/PP na potek in kinetiko reakcij razgradnje odpadne embalaže iz PP v superkritični vodi. PP je trd termoplastičen polimer z gostoto med 0,9 in 0,92 g/cm3. V mnogih pogledih je podoben polietilenu, vendar z večjo mehansko in natezno trdnostjo ter toplotno stabilnostjo. Odporen je proti polarnim topilom, kislinam, raztopinam soli in olju ter neodporen proti kloriranim ogljikovodikom. Zaradi dobrih mehanskih in fizikalnih lastnosti je eden izmed najbolj zastopanih polimerov v svetu. Uporablja se v različne namene, kot so folije, plastenke za mineralno vodo, povratne plastenke, v ploščah, ceveh, avtomobilski industriji ter v beli tehniki. Zaradi velike zastopanosti tega polimera in vpliva ter kopičenja v okolju smo izvedli hidrotermično degradacijo pisanega PP in brezbarvnega PP. Hidrotermično degradacijo smo izvajali v visokotemperaturnem in visokotlačnem šaržnem reaktorju pri temperaturah 425 °C in 450 °C ter reakcijskih časih od 15 do 240 min. Nastale produkte smo filtrirali ter analizirali s pomočjo plinske kromatografije/masne spektrometrije GC/MS ter določili vsebnost celotnega organskega ogljika (TOC). Ugotovili smo, da je največji izkoristek plina nastal pri 240 min degradaciji – tako barvnega kot brezbarvnega PP v superkritični vodi – najmanj pa ga je nastalo pri 15-minutni degradaciji. Najbolj zastopane komponente so metan, etan, propan, izobutan ter ogljikov dioksid. Dokazali smo, da je največji donos alkanov prisoten le pri višji temperaturi. Majhne razlike v vsebnosti alkanov, ki so prisotni pri isti temperaturi, lahko pripišemo aditivom ter različnim primesem, ki jih vsebuje pisani PP. Izkoristki nastale oljne faze s podaljševanjem reakcijskega časa upadajo, saj se dolgi ogljikovodiki cepijo na krajše.

Ključne besede

hidrotermična degradacija;superkritična voda;barvni PP;brezbarvni PP;diplomske naloge;

Podatki

Jezik:	Slovenski jezik
Leto izida:	2019
Tipologija:	2.11 - Diplomsko delo
Organizacija:	UM FKKT - Fakulteta za kemijo in kemijsko tehnologijo
Založnik:	[K. Kranjčec]
UDK:	678.742.3:54-139(043.2)
COBISS:	22604310
Št. ogledov:	735
Št. prenosov:	35
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Angleški jezik
Sekundarni naslov:	Hydrothermal degradation of waste from polypropylene
Sekundarni povzetek:	The purpose of the following work was to investigate the hydrothermal degradation of polypropylene waste packaging (PP) using supercritical water, and determine the resulting products. A comparison of a colored and colorless PP has been done. The impact of process parameters, such as pressure, temperature and water/PP proportion on the course of reaction and the kinetics of the decomposition of waste packaging from PP in supercritical water has been studied. Polypropylene (PP) is a solid thermoplastic polymer with density between 0.9 and 0.92 g/cm3. It is quite similar to polyethylene, but with greater mechanical and tensile strength and thermal stability. It is resistant to polar solvents, acids, saline and oil solutions and it is not resistant to chlorinated hydrocarbons. Because of its good mechanical and physical properties, it is one of the most represented polymers in the world. It is used for various purposes, such as foils, mineral water bottles, return bottles, plates, pipes, automotive and white goods. Due to the high abundance of this polymer and his influence and accumulation in the environment, hydrothermal degradation of the coloured PP and colorless PP has been investigated. Hydrothermal degradation was carried out in a high temperature and high pressure batch reactor at temperatures of 425 °C and 450 °C and reaction time of 15–240 min. The resulting products were filtered and analyzed by gas chromatography/GC and MS/mass spectrometry and we determined the total organic carbon content (TOC) has been determined. We found that the maximum gas yield was obtained at 240 min degradation of both the coloured and the colorless PP in supercritical water, and the minimum yield was obtained at 15 minute degradation. The most represented components are methane, ethane, propane, isobutane and carbon dioxide. The results of analyses showed that the maximum yield of alkanes is obtained only at a higher temperature. The small differences in the amount of obtained alkanes at the same temperature can be attributed to additives which are present in a coloured PP. The yield of the resulting oil phase decreases with the prolongation of the reaction time, beacuse the long hydrocarbons are splited into shorter molecules.
Sekundarne ključne besede:	hydrothermal degradation;supercritical water;color PP;colorless PP;
Vrsta dela (COBISS):	Diplomsko delo/naloga
Konec prepovedi (OpenAIRE):	2020-12-30
Komentar na gradivo:	Univ. v Mariboru, Fak. za kemijo in kemijsko tehnologijo
Strani:	VIII, 35 str.
ID:	11205379