| 1. |
- Arm, Maria, et al.
(författare)
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Gasbildning i aska
- 2006
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Rapport (övrigt vetenskapligt/konstnärligt)
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| 2. |
- Backman, Rainer, et al.
(författare)
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Metalliskt aluminium i förbränningen : Metallic aluminum in combustion
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet har visat att det är mycket svårt att få tunn aluminiumfolie, som normalt finns i bl.a. hushållsavfall, att oxidera oberoende av tid, temperatur och förbränningsatmosfärens sammansättning. Vidare har svävhastighetsmätningar visat att tunn plastbelagd aluminiumfolie lätt kan ryckas med rökgaserna vid normala rökgashastigheter (1-5 m/s).
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| 3. |
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| 4. |
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| 5. |
- Berg, Magnus, et al.
(författare)
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Förbränning av utsorterade avfallsfraktioner
- 2005
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet har visat på möjligheter och problem vid förbränning av utsorterade avfallsfraktioner bestående av papper, trä och plast i fluidbädd. Denna typ av bränslen kan antingen samförbrännas eller användas som enda bränsle i en avfallspanna. I båda fallen bör gällande gränsvärden för emissioner till luft kunna klaras men man får däremot räkna med ökade drift- och underhållskostnader, främst beroende på ökade problem med påslag och korrosion. Dessa problem är starkt kopplade till bränslets innehåll av oönskade ämnen såsom klor, alkali och vissa andra metaller. Innehållet av dessa ämnen varierar kraftigt mellan olika bränslefraktioner och därmed blir omfattningen av problemen beroende både av inblandningsgrad och av bränslets ursprung. Projektet har även visat att mängden påslag kan minskas genom tillsats av svaveladditiv samtidigt som den kemiska samansättningen i påslagen förändras på ett sådant sätt att även risken för korrosion bör minska.
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| 6. |
- Bergström, Dan, et al.
(författare)
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Effects of raw material particle size distribution on the characteristics of Scots pine sawdust fuel pellets
- 2008
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Ingår i: Fuel processing technology. - Amsterdam : Elsevier. - 0378-3820 .- 1873-7188. ; 89:12, s. 1324-1329
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Tidskriftsartikel (refereegranskat)abstract
- In order to study the influence of raw material particle size distribution on the pelletizing process and the physical and thermomechanical characteristics of typical fuel pellets, saw dust of Scots pine was used as raw material for producing pellets in a semi industrial scaled mill (similar to 300 kg h(-1)). The raw materials were screened to a narrow particle size distribution and mixed into four different batches and then pelletized under controlled conditions. Physical pellet characteristics like compression strength, densities, moisture content, moisture absorption and abrasion resistance were determined. In addition, the thermochemical characteristics, i.e. drying and initial pyrolysis, flaming pyrolysis, char combustion and char yield were determined at different experimental conditions by using a laboratory-scaled furnace. The results indicate that the particle size distribution had some effect on current consumption and compression strength but no evident effect on single pellet and bulk density, moisture content, moisture absorption during storage and abrasion resistance. Differences in average total conversion time determined for pellet batches tested under the same combustion conditions was less than 5% and not significant. The results are of practical importance suggesting that grinding of saw dust particle sizes below 8 mm is probably needless when producing softwood pellets. Thus it seem that less energy could be used if only over sized particles are grinded before pelletizing.
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| 7. |
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| 8. |
- Boman, Christoffer, et al.
(författare)
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Characterization of inorganic particulate matter from residential combustion of pelletized biomass fuels
- 2004
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 18:2, s. 338-348
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Tidskriftsartikel (refereegranskat)abstract
- The increased focus on potential adverse health effects associated with exposure to ambient particulate matter (PM) motivates a careful characterization of particle emissions from different sources. Combustion is a major anthropogenic source of fine PM, and, in urban areas, traditional residential wood combustion can be a major contributor. New and upgraded biomass fuels have become more common, and fuel pellets are especially well-suited for the residential market. The objective of the present work was to determine the mass size distributions, elemental distributions, and inorganic-phase distributions of PM from different residential combustion appliances and pelletized biomass fuels. In addition, chemical equilibrium model calculations of the combustion process were used to interpret the experimental findings. Six different typical pellet fuels were combusted in three different commercial pellet burners (10-15 kW). The experiments were performed in a newly designed experimental setup that enables constant-volume sampling. Total-PM mass concentrations were measured using conventional filters, and the fractions of products of incomplete combustion and inorganic material were thermally determined. Particle mass size distributions were determined using a 13-step low-pressure cascade impactor with a precyclone. The PM was analyzed for morphology (using environmental scanning electron microscopy, ESEM), elemental composition (using energy-dispersive spectroscopy, EDS), and crystalline phases (using X-ray diffractometry, XRD). For complementary chemical structural characterization, time-of-flight secondary ion mass spectrometry (TOF-SIMS), X-ray photoelectron spectroscopy XPS and X-ray absorption fine structure (XAFS) spectroscopy were also used. The emitted particles were mainly found in the fine ( less than or equal 1 μm) mode with mass median aerodynamic diameters of 0.20 - 0.39 μm and an average PM1 of 89.5% ± 7.4% of total PM. Minor coarse-mode fractions (>1 μm) were present primarily in the experiments with bark and logging residues. Relatively large and varying amounts (28%-92%) were determined to be products of incomplete combustion. The inorganic elemental compositions of the fine particles were dominated by potassium, chlorine, and sulfur, with minor amounts of sodium and zinc. The dominating alkali phase was KCl, with minor but varying amounts of K3Na(SO4)2 and, in some cases, also K2SO4. The results showed that zinc is almost fully volatilized, subsequently and presumably forming a more complex solid phase than that previously suggested (ZnO). However, the formation mechanism and exact phase identification remain to be elucidated. With some constrains, the results also showed that the amounts and speciation of the inorganic PM seemed to be quite similar to that predicted by chemical equilibrium calculations.
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