Change search
ReferencesLink to record
Permanent link

Direct link
Mixed fuels composed of household waste and waste wood: Characterization, combustion behaviour and potential emissions
Umeå University, Faculty of Science and Technology, Department of Chemistry. Umeå University.
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

   Incineration with energy recovery is the main disposal strategy for waste that cannot be reused or recycled, and a well-established source of energy in Europe, especially in Sweden where 2.2 Mtonnes of waste including domestic and imported municipal solid waste (MSW) and waste wood (WW) were combusted during 2015. However, owing to its inherent heterogeneous composition, inclusion of such waste in Waste-to-energy (WtE) technologies is challenging. These heterogeneities may lead to operationally-related issues in the WtE facilities and contribute to toxic emissions, which can be reduced by waste pre-treatment technologies.

   This thesis examines the variations in the composition of MSW and WW streams used as a fuel supply in WtE facilities after undergoing waste pre-treatment technologies, and the effect of fuel composition on its combustion behaviour and formation of persistent organic pollutants (POPs) such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). The overall objective is to contribute to a more thorough understanding of the selection of waste pre-treatment technologies to mitigate harmful emissions into the atmosphere when waste fuels are combusted in WtE facilities.

   This thesis describes the high variability of contaminants in domestic and imported WW and suggests adaptation of WW pre-treatment techniques to produce fuels with a low potential for generating pollutants. A comparison of mechanical solid waste pre-treatments revealed that screening and shredding is more efficient than extrusion for reducing emissions of pollutants such as PCDDs and PCDFs in combustion. The evaluation of the combustion behaviour of MSW-based fuels showed a three-stage oxidative decomposition, and an acceleration of the decomposition of the MSW compared to the lignocellulosic materials, which may be attributed to the presence of food waste and plastics in the MSW. Combustion tests of fuel blends containing WW and MSW-based fuels with different food waste content suggested that WW, not food waste content, is the key factor for the formation of PCDDs, PCDFs, and polychlorinated biphenyls (PCB), benzenes (PCBzs) and phenols (PCPhs). Torrefaction may be a suitable technology for improving the properties of waste as a fuel e.g. due to its low PCDD and PCDF emissions.

Abstract [sv]

Förbränning med energiåtervinning är det huvudsakliga sättet att ta hand om avfall som inte kan återanvändas eller återvinnas. Det är en väletablerad energikälla i Europa och särskilt i Sverige där 2,2 miljoner ton avfall, däribland inhemskt och importerat hushållsavfall och returträ, förbrändes under 2015. På grund av den heterogena sammansättningen hos hushållsavfall och returträ är förbränning av dessa material i anläggningar med energiåtervinning (så kallade WtE-anläggningar) förknippade med en del driftsrelaterade utmaningar. Det kan även ge upphov till miljöfarliga utsläpp, som dock kan reduceras genom förbehandling av avfallet.

I denna avhandling har variationer i sammansättningen hos hushållsavfall och returträ som förbränns i WtE-anläggningar undersökts. Effekten av bränslemixens sammansättning och ev förbehandling på bränslets förbränningsegenskaper samt bildning av långlivade organiska föroreningar (så kallade POPar) såsom polyklorerade dibenso-p-dioxiner och polyklorerade dibensofuraner vid förbränning har utvärderats. Det övergripande målet är att bidra till en djupare förståelse av hur valet av förbehandlingsteknik för avfall kan bidra till att minska skadliga utsläpp till luft när avfallsbränslen förbränns i WtE-anläggningar.

Denna avhandling beskriver den stora variabiliteten av metall- och materialföroreningar i inhemskt och importerat returträ och föreslår förbehandlingstekniker för att producera bränslen med låg potential att generera föroreningar. En jämförelse av mekaniska förbehandlingstekniker visade att mekanisk sönderdelning och separering (krossning och siktning) är mer effektivt än s.k. högtrycks-pressning för att minska utsläppen av föroreningar som dioxiner och furaner vid förbränning. Utvärderingen av bränslemixar innehållande hushållsavfall uppvisade en oxidativ nedbrytning i tre steg vid förbränning, och en accelererad nedbrytning av avfallsmaterialet jämfört med vedmaterialet i bränslet, troligen som effekt av innehållet av matavfall och plast i hushållsavfallet. Förbränningsförsök med bränsleblandningar av returträ och hushållsavfall med olika innehåll av matavfall visade att mängden returträ, och inte mängden matavfall, är den viktigaste faktorn för bildning av dioxiner, furaner, klorbifenyler, klorbensener, och klorfenoler. Torrefiering kan vara en lämplig teknik för att förbättra avfallets bränsleegenskaper, t.ex. på grund av dess låga emissioner.

Place, publisher, year, edition, pages
Umeå: Umeå University , 2016. , 77 p.
Keyword [en]
MSW, RDF, persistent organic pollutants, PCDD, PCDF, solid waste pre-treatment, torrefaction, food waste, contaminated wood
National Category
Chemical Sciences
Identifiers
URN: urn:nbn:se:umu:diva-127227ISBN: 978-91-7601-592-6OAI: oai:DiVA.org:umu-127227DiVA: diva2:1044533
Public defence
2016-12-02, KB.E3.03, KBC-huset, UMEÅ, 09:00 (English)
Opponent
Supervisors
Available from: 2016-11-11 Created: 2016-11-03 Last updated: 2016-11-10Bibliographically approved
List of papers
1. Assessment of chemical and material contamination in waste wood fuels: a case study ranging over nine years
Open this publication in new window or tab >>Assessment of chemical and material contamination in waste wood fuels: a case study ranging over nine years
2016 (English)In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 49, 311-319 p.Article in journal (Refereed) Published
Abstract [en]

The increased demand for waste wood (WW) as fuel in Swedish co-combustion facilities during the last years has increased the import of this material. Each country has different laws governing the use of chemicals and therefore the composition of the fuel will likely change when combining WW from different origins. To cope with this, enhanced knowledge is needed on WW composition and the performance of pre-treatment techniques for reduction of its contaminants. In this study, the chemical and physical characteristics of 500 WW samples collected at a co-combustion facility in Sweden between 2004 and 2013 were investigated to determine the variation of contaminant content over time. Multivariate data analysis was used for the interpretation of the data. The concentrations of all the studied contaminants varied widely between sampling occasions, demonstrating the highly variable composition of WW fuels. The efficiency of sieving as a pre-treatment measure to reduce the levels of contaminants was not sufficient, revealing that sieving should be used in combination with other pre-treatment methods. The results from this case study provide knowledge on waste wood composition that may benefit its management. This knowledge can be applied for selection of the most suitable pre-treatments to obtain high quality sustainable WW fuels.

Place, publisher, year, edition, pages
Elsevier, 2016
Keyword
Trace contaminants, Waste wood, Volatile metals, Size fractions, PCA
National Category
Environmental Sciences
Identifiers
urn:nbn:se:umu:diva-119671 (URN)10.1016/j.wasman.2015.11.048 (DOI)000372676300034 ()26709051 (PubMedID)
Available from: 2016-04-25 Created: 2016-04-25 Last updated: 2016-11-10Bibliographically approved
2. The combined effect of plastics and food waste accelerates the thermal decomposition of refuse-derived fuels and fuel blends
Open this publication in new window or tab >>The combined effect of plastics and food waste accelerates the thermal decomposition of refuse-derived fuels and fuel blends
Show others...
2016 (English)In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 180, 424-432 p.Article in journal (Refereed) Published
Abstract [en]

Mechanical treatments such as shredding or extrusion are applied to municipal solid wastes (MSW) to produce refuse-derived fuels (RDF). In this way, a waste fraction (mainly composed by food waste) is removed and the quality of the fuel is improved. In this research, simultaneous thermal analysis (STA) was used to investigate how different mechanical treatments applied to MSW influence the composition and combustion behaviour of fuel blends produced by combining MSW or RDF with wood in different ratios. Shredding and screening resulted in a more efficient mechanical treatment than extrusion to reduce the chlorine content in a fuel, which would improve its quality. This study revealed that when plastics and food waste are combined in the fuel matrix, the thermal decomposition of the fuels are accelerated. The combination of MSW or RDF and woody materials in a fuel blend has a positive impact on its decomposition.

Keyword
Municipal solid waste (MSW), Thermochemical conversion, Co-combustion, DSC, TG-FTIR
National Category
Chemical Sciences
Identifiers
urn:nbn:se:umu:diva-123352 (URN)10.1016/j.fuel.2016.04.062 (DOI)000375950300047 ()
Funder
Bio4Energy
Available from: 2016-07-05 Created: 2016-07-01 Last updated: 2016-11-10Bibliographically approved
3. Emissions from co-combustion of demolition and construction wood and household waste fuel blends
Open this publication in new window or tab >>Emissions from co-combustion of demolition and construction wood and household waste fuel blends
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Organic Chemistry
Identifiers
urn:nbn:se:umu:diva-127414 (URN)
Available from: 2016-11-10 Created: 2016-11-10 Last updated: 2016-11-10
4. Fate of metals and emissions of organic pollutants from torrefaction of waste wood, MSW, and RDF
Open this publication in new window or tab >>Fate of metals and emissions of organic pollutants from torrefaction of waste wood, MSW, and RDF
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Organic Chemistry
Identifiers
urn:nbn:se:umu:diva-127415 (URN)
Available from: 2016-11-10 Created: 2016-11-10 Last updated: 2016-11-10

Open Access in DiVA

image(8235 kB)22 downloads
File information
File name IMAGE01.pdfFile size 8235 kBChecksum SHA-512
7dc41d066ff8cc0a7f2915419e4bebca2a35ad1d62b0530ca6648bd39ac04eb5bfec1383d3ac269c9e0bf4d58ac33169f12b271456cd23e29d79756c7b65d76d
Type imageMimetype application/pdf
spikblad(38 kB)22 downloads
File information
File name SPIKBLAD01.pdfFile size 38 kBChecksum SHA-512
b23e579ce046350a738e57f166630141135ebcbb6321e35bf1aef009a5c5cb5bda9d59fb3ceea266ac6d17f2b6c33a9a5628714c30f2ff25941e3fe034c3472f
Type spikbladMimetype application/pdf
fulltext(2118 kB)45 downloads
File information
File name FULLTEXT03.pdfFile size 2118 kBChecksum SHA-512
cc4982547342667324eb9fde2d2337d550329b2adb029f5b336e2e3e19bf2bd35e87710d9bd12241fd19b00a7e0bc254ed7391c9932a58c6eeabfeac85f190a2
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Edo Giménez, Mar
By organisation
Department of Chemistry
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
Total: 45 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 178 hits
ReferencesLink to record
Permanent link

Direct link