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Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis

Thesis (MEng)--Stellenbosch University, 2014.

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Main Author: Bradfield, Frances Louise
Other Authors: Knoetze, J. H.
Format: Thesis
Language:en_ZA
Published: Stellenbosch : Stellenbosch University 2014
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access_status_str Open Access
author Bradfield, Frances Louise
author2 Knoetze, J. H.
author_browse Bradfield, Frances Louise
Knoetze, J. H.
author_facet Knoetze, J. H.
Bradfield, Frances Louise
author_sort Bradfield, Frances Louise
collection Thesis
dc_rights_str_mv Stellenbosch University
description Thesis (MEng)--Stellenbosch University, 2014.
format Thesis
id oai:scholar.sun.ac.za:10019.1/86670
institution Stellenbosch University (South Africa)
language en_ZA
last_indexed 2026-06-10T12:43:05.531Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2014
publishDateRange 2014
publishDateSort 2014
publisher Stellenbosch : Stellenbosch University
publisherStr Stellenbosch : Stellenbosch University
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source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/86670 Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis Bradfield, Frances Louise Knoetze, J. H. Gorgens, Johann F. Stellenbosch University. Faculty of Engineering. Dept. of Process Engineering. Dissertations -- Process engineering Waste products as fuel Biomass conversion Biomass energy Recycling (Waste etc.) Heat recovery Pyrolysis UCTD Theses -- Process engineering Thesis (MEng)--Stellenbosch University, 2014. ENGLISH ABSTRACT: Concerns surrounding the world’s current dependence on quickly depleting fossil fuels and their negative environmental impacts have brought about much research into renewable and sustainable energy sources. With population and economic growth not only is this dependence increasing but there is an increasing production of waste by society in general. With space becoming a premium commodity and environmental protection a necessity, landfilling of the majority of the world’s waste is no longer feasible. Thus, research is being carried out into waste-to-energy (WTE) processes and refuse derived fuels (RDF). This study focuses on thermochemical conversion, specifically pyrolysis of solid wastes as a means of energy product recovery. Before a specific waste stream can be used in WTE or RDF contexts its composition and degradation behaviour needs to be investigated. For this reason, a full physical characterisation of the municipal solid waste (MSW) from the Stellenbosch municipality was carried out. It was found that the composition of waste differs between areas within the municipality but the composition of the waste in general compares well with international data. It was found that six main components present in the recyclables stream; namely high and low density polyethylene (HD/LDPE), poly(ethylene terephthalate) (PET), glossy paper, office paper and newspaper would be suitable for thermochemical conversion. The thermal properties and pyrolytic degradation of these six components were investigated by multi heating rate thermogravimetric analysis (TGA) from which kinetic parameters (activation energy, pre-exponential factor and kinetic rate constants) were calculated by a differential isoconversional method. The volatiles released during degradation were identified by way of online mass spectrometry (TGA-MS) yielding six individual kinetic schemes. In order to gauge to what extent milligram pyrolytic experimentation (TGA-MS) can be used to predict larger scale pyrolytic behaviour, runs were performed on one plastic (HDPE) and one paper (glossy paper) sample on a gram scale pyrolytic plant under both slow and vacuum conditions. It was found that, especially for high thermal conductivity samples, yields on gram scale experimentation can be accurately predicted on a milligram scale. Further, the compositions of slow pyrolysis oils from glossy paper, obtained by gas chromatography–mass spectrometry (GC-MS), were compared to TGA-MS results as well as off gases captured from TGA runs by thermal desorption (TGA/TD-GC-MS). It was found that TGA-MS and TGA/TD-GC-MS can be used to predict the main functional groups in pyrolysis oil produced on a gram scale. Thus small scale experimentation can be used to determine the suitability of different waste components for pyrolytic conversion. AFRIKAANSE OPSOMMING: Kommer oor die wêreld se huidige afhanklikheid van fossielbrandstowwe en die negatiewe uitwerking op die omgewing het baie navorsing oor hernubare en volhoubare energie bronne meegebring. Bevolking en ekonomiese groei veroorsaak 'n toename in hierdie afhanklikheid en in die produksie van afval deur die samelewing. Daar is baie min onbenutte grond oop en die beskerming van die omgewing het noodsaaklik geword. Dus is storting van die meeste van die wêreld se afval nie meer ‘n aanvaarbare opsie nie. As gevolg daarvan word daar tans navorsing in afval-tot-energie (ATE) prosesse en afval afgeleide brandstowwe (AAB) gedoen. Hierdie studie fokus op die termochemiese omskakeling van afval, spesifiek pirolise, as 'n methode vir energie-produk hernuwing. Voordat 'n spesifieke afvalstroom gebruik kan word as 'n AAB moet die samestelling en afbrekings gedrag eers ondersoek word. Daarom is 'n volledige fisiese karakterisering van die munisipale afval (MA) van Stellenbosch munisipaliteit uitgevoer. Resultate het getoon dat daar ‘n verskil in die samestelling van afval tussen die gebiede binne die munisipaliteit is. Afgesien daarvan vergelyk die samestelling van die afval in die algemeen goed met internasionale data. Daar is gevind dat daar ses belangrike komponente teenwoordig is in die herwinbare stroom wat geskik sou wees vir termochemiese omskakeling, naamlik; hoë en lae digtheid poliëtileen (HD/LDPE), poli(etileen tereftelaat) (PET), glans, kantoor en koerant papier. Die termiese eienskappe en termiese afbreking van hierdie ses komponente is ondersoek deur middel van multi-verhittimgs tempo termogravimetriese analise (TGA) waaruit kinetiese parameters (aktiveringsenergie, pre-eksponensiële faktor en kinetiese snelheidskonstantes) deur 'n differensiële omskakelings metode bereken is. Die vlugtige komponente wat tydens die afbreking vrygestel is, is geïdentifiseer deur aanlyn-massaspektrometrie (TGA-MS) wat ses individuele kinetiese skemas verskaf. Om vas te stel tot watter mate milligram pirolitiese eksperimente (TGA-MS) gebruik kan word om op ‘n groter skaal die pirolitiese gedrag te kan voorspel, is eksperimentele lopies op een plastiek- (HDPE) en een papier (glans papier) monster op 'n laboratorium skaal pirolise opstelling onder stadige- en vakuum omstandighede uitgevoer. Daar is gevind dat, veral met hoë hitte geleiding komponente, die opbrengs op gram skaal eksperimente akkuraat voorspel kan word op ‘n milligram skaal. Verder was die samestelling van die stadige pirolise olies uit glans papier, wat verkry word deur gaschromatografie-massaspektrometrie (GC-MS), vergelyk met TGA-MS resultate sowel as af-gasse gevang van TGA lopies deur termiese desorpsie (TGA/TD-GC –MS). Daar is gevind dat TGA-MS en TGA/TD-GC-MS gebruik kan word om die belangrikste funksionele groepe in pirolise olie, wat op 'n gram skaal geproduseer word, te voorspel. Dus kan milligram eksperimente gebruik word om die geskiktheid van afval komponente vir pirolitiese omskakeling te bepaal. Masters 2014-04-16T17:31:30Z 2014-04-16T17:31:30Z 2014-04 Thesis http://hdl.handle.net/10019.1/86670 en_ZA Stellenbosch University viii, 175 p. : ill. application/pdf Stellenbosch : Stellenbosch University
spellingShingle Dissertations -- Process engineering
Waste products as fuel
Biomass conversion
Biomass energy
Recycling (Waste etc.)
Heat recovery
Pyrolysis
UCTD
Theses -- Process engineering
Bradfield, Frances Louise
Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis
title Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis
title_full Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis
title_fullStr Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis
title_full_unstemmed Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis
title_short Examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis
title_sort examination of the thermal properties of municipal solid waste and the scalability of its pyrolysis
topic Dissertations -- Process engineering
Waste products as fuel
Biomass conversion
Biomass energy
Recycling (Waste etc.)
Heat recovery
Pyrolysis
UCTD
Theses -- Process engineering
url http://hdl.handle.net/10019.1/86670
work_keys_str_mv AT bradfieldfranceslouise examinationofthethermalpropertiesofmunicipalsolidwasteandthescalabilityofitspyrolysis