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- Eriksson, Gunnar, et al.
(författare)
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Förbränningskarakterisering av rapsmjöl och förslag till optimalt nyttjande i olika förbränningsanläggningar
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- When rape oil is chemically extracted, rape seed meal, a solid residue remains. Currently, it is used as animal feed. Several plants for the production of rape methyl ester (RME, biodiesel) are in operation or under construction. Combustion properties have been studied for rape seed meal produced as a by product to rape-methyl esther (RME, biodiesel). Composition of the material has been measured, using proximate and ultimate analysis. The lower heating value was 18.2 ± 0,3 MJ/kg d.w. and the ash content was 7-8 percent d.w. The material is rich in nitrogen and sulphur. Concentrations of K, P, Ca and Mg are high in the fuel. Rape seed meal was mixed with bark and pelletised. Bark pellets were also used as a reference fuel. Pellets with 10 and 30 percent rape seed meal were produced. Material with 80 percent rape seed meal and 20 percent planer shavings was also pelletised. Wood had to be added to provide enough friction in the pelletising process, with adapted equipment rape seed meal could probably be easily pelletised). The material was studied using Thermo-Gravimetric Analysis (TGA), and compared with data from tests with wood powder. The pyrolysis of the rape seed meal has a characteristic temperature of 320oC. Devolatilisation starts at 150 oC (at a lower temperature than for wood powder), and proceeds within a rather wide temperature range. The probable cause is the difference in organic content, in particular protein content. The result does not suggest that the material will be difficult to ignite. Experiments in a bench-scale fluidised bed (5 kW) showed that pellets containing only bark, and the mixture rape seed meal/wood had a bed agglomeration temperature well over the normal operational bed temperature. For the fuel mixtures rape seed meal and bark, the agglomeration temperature was slightly over the operational temperature. Particle emissions from fluidised bed combustion and grate combustion were, the latter simulated using a commercial pellet burner, were roughly doubled with fuels containing rape seed meal compared to bark. In the powder burner tests, particle emissions increased with a factor 17 with rape seed meal compared to wood powder. The emitted particles were mainly found in the fine (< 1 µm) mode during grate and powder combustion. During fluidized bed combustion the total particulate matter consisted both of a coarse (>1 µm) and a fine mode fraction. The particles from grate combustion of bark contain mostly K, S, Na and Cl apart from oxygen and carbon. When rape seed meal is present, Cl and Na concentrations decrease considerably and the main contents of the particles are K and S (and O and C). The results from the X-ray Diffraction Spectroscopy (XRD) analyses showed the presence of crystalline K2SO4 och KCl. The fine particles (<1 µm) from powder combustion contain mainly K, P and S. The only identified crystalline phase was K2SO4, suggesting that most phosphorus was in the amorphous phase, i.d. most probably molten. The deposit formation on a cooled probe was studied during the fluidized bed and powder combustion experiments. The fine particles deposited during fluidised bed combustion contained K, Cl and S. When bark was combusted in the fluidised bed, the coarse fraction contained Ca and Si, when rape seed meal in different mixes was combusted this changed to P, K, Ca and Mg. The deposits formed during combustion of rape seed meal in the powder burner were mainly made up of phosphates (Ca-, Mg/K-, Ca/Mg-phosphates) and MgO. Sintered material (slag) from grate combustion of bark contained mainly Si, Ca, K and Al, probably as silicates. Adding rape seed meal tended to increase P, Ca and Mg while Si and Ca content tended to decrease. Through XRD a number o crystalline phases in the sintered material and the rest of the bottom ashes could be identified. NO emissions from the combustions tests increased two to four times with rape seed meal compared to typical wood fuels. For the fluidised bed test, SO2 concentrations were rather high for the rape seed meal pellets (with 20 percent wood), still only about 20 percent of the sulphur in the fuel formed SO2. For the grate combustion and powder burner combustion, 60 percent and 70 percent of the sulphur respectively formed SO2. HCl emissions were low for all tests. The rather high emissions of NOx and SOx mean that the material should be used in large-scale facilities with external SOx and NOx cleaning. In smaller facilities, the material may be used in small amounts mixed with other fuels. The risk of slagging is not very high, and should not rule out grate combustion of pellets with rape seed meal mixed with other fuels. The risk of corrosion of superheater surfaces during combustion is probably low since the smaller-size particles formed at fluidised bed combustion and grate combustion contain K2SO4. However, a large fraction of the particles formed in powder burner combustion probably contains low temperature melting K2PO4, making the risk for deposit formation significant. Rape seed meal for powder burner applications should be used with care. The content of phosphorus in the material may be an advantage when mixes of rape seed meal and other fuels are considered. The high affinity between potassium and phosphorus means that more sulphur in the fuel will be available for sulphatising of any KC. (formed from combustion of many forest and agricultural fuels). Use of rape seed meal as a sulphur containing additive could thus be an option. For grate combustion and fluidised bed combustion, addition of rape seed meal may reduce the risk of slagging and bed agglomeration, respectively. Full scale tests in fluidised beds or grate combustors with problematic biofuels (containing Cl and K) would be useful to test whether ash-reduced operational problems could be reduced through the addition of rape seed meal.
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- Andersson, Erik, 1979-, et al.
(författare)
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Kollegialt Lärande i Örebros Skolor – KLÖS-projektet : Hur kan lärares kollegiala lärprocesser stödjas i syfte att skapa hållbara strukturer för utvecklingsarbete?
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Projektet KLÖS har undersökt hur lärares kollegiala lärprocesser kan stödjas i syfte att skapa hållbara strukturer för utvecklingsarbete. Målet var att skapa en Örebromodell för kollegialt lärande. En avslutande reflektion kring resultatet är att etableringen av denna modell kräver ett omfattande engagemang och tar tid att få på plats. Det är vår uppfattning att ett flertal aspekter återstår att undersöka. Bland annat är det intressant att undersöka hur arbetet med det kollegiala lärandet fortskrider på pilotskolan. Frågor som är intressanta är: Vilka faktorer har betydelse för att arbetet med kollegialt lärande ska bli permanent och fungera som ett naturligt sätt att arbeta med utveckling av praktiken? Vad blir resultatet av de utvecklingsomgångar som genomförts? Hur följs detta resultat upp och leder det till bestående gynnsamma förändringar? Frågorna handlar om hållbarhet och därmed om hur projektet går från att vara ett projekt som avslutas och glöms bort till att bli ett levande verktyg för utvecklingsarbete som kan göra en verklig skillnad i och för praktiken över tid. Eftersom mycket tid och resurser används till utvecklingsarbete i skolan är det viktigt att det arbete som görs verkligen leder till en konkret och för verksamheten gynnsam förändring. Det innebär att frågan om utvecklings- arbetets hållbarhet är en av de viktigaste frågorna. Det verktyg som utvecklats i projektet och som kommit att symbolisera det kollegiala arbetet på pilotskolan är KLÖS-hjulet. Frågan om hur KLÖS-hjulet 2.0 kan utvecklas och anpassas så att det verkligen blir ett flexibelt och användbart verktyg för att stötta det kollegiala lärandet är kanske den alla viktigaste konkreta frågan. Frågor som är besläktade med frågan om hållbarhet är de som syftar till att undersöka hur det kollegiala lärandet kan bli mer robust. Till dessa hör frågor om hur lärledarens roll kan förstärkas, hur verktyg som stöttar lärares observation och analys av den egna verksamheten kan designas, hur ansvar och engagemang på alla nivåer kan förstärkas och bli synligt samt hur arbetet med kollegialt lärande kan utvärderas. Vi har under projektets gång sett hur lärare behöver stöd i arbetet med att systematiskt identifiera behov i verksamheten för att sedan utforska möjligheter att utveckla och förändra praktiken. Medverkan från forskare som ställt frågor, problematiserat och belyst olika perspektiv har i flera fall varit avgörande för hur ett utvecklingsbehov har identifierats, avgränsats och formulerats som en undersökningsbar fråga. Det är av avgörande betydelse att utvecklingsarbetet inte står och faller med denna medverkan. Verksamheten måste själv ta fram strukturer för hur lärare och lärledare får ett tillfredsställande stöd i sitt utvecklingsarbete så att de har möjlighet att göra kollegialt lärande till en naturlig del av sitt arbete där de känner sig så bekanta med KLÖS-hjulet att de själva kan ställa de frågor som krävs. Således behöver många funktioner, både centralt och lokalt samverka för att vidareutveckla och stötta kollegialt lärande för att utveckla undervisningen i Örebro skolor.
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- Andersson, Mathias H., et al.
(författare)
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Epibenthic colonization of concrete and steel pilingsin a cold-temperate embayment : a feld experiment
- 2009
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Ingår i: Helgoland Marine Research. - : Springer Science and Business Media LLC. - 1438-387X .- 1438-3888. ; 63:3, s. 249-260
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Tidskriftsartikel (refereegranskat)abstract
- With large-scale development of offshore wind farms, vertical structures are becoming more common in open water areas. To examine how vertical structures of different materials may be colonized by epibenthic organisms, an experiment was carried out using steel and concrete pilings constructed to resemble those commonly used in wind farm constructions as well as in bridges, jetties and oil platforms. The early recruitment and succession of the epibenthic communities were sampled once a month for the first 5 months and then again after 1 year. Further, the fish assemblages associated with the pillars were sampled and compared to natural areas. The main epibenthic species groups, in terms of coverage, diVered between the two materials at five out of six sampling occasions. Dominant organisms on steel pillars were the barnacle Balanus improvisus,the calcareous tubeworm Pomatoceros triqueter and the tunicate Ciona intestinalis. On the concrete pillars, the hydroid Laomedea sp. and the tunicates Corella parallelogramma and Ascidiella spp. dominated. However, there was no different in coverage at different heights on the pillars or in biomass and species abundance at different directions (north-east or south-west) 5 months after submergence. Fish showed overall higher abundances and species numbers on the pillars (but no difference between steel and concrete)compared to the surrounding soft bottom habitats but not compared to natural vertical rock walls. Two species were attracted to the pillars, indicating a reef effect; Gobiusculus flavescens and Ctenolabrus rupestris. The bottom-dwelling gobies, Pomatoschistus spp., did not show such preferences.
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| 9. |
- Andersson, Mathias H., et al.
(författare)
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Fish and sessile assemblages associated with wind-turbineconstructions in the Baltic Sea
- 2010
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Ingår i: Marine and Freshwater Research. - 1323-1650 .- 1448-6059. ; 61:6, s. 642-650
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Tidskriftsartikel (refereegranskat)abstract
- Offshore wind farms are being built at a high rate around the world to meet the demand for renewable energy. We studied fish and sessile communities on and around offshore wind-turbine foundations in the southern Baltic Sea, 7 years after construction, using visual census techniques to determine how fish, sessile-invertebrate and algal communities are affected by the introduction of such structures. Fish assemblages were dominated by two-spotted gobies (Gobiusculus flavescens) that were found in large shoals in close association with the vertical surface. At the seabed, close to the foundation, the black goby (Gobius niger) was recorded in large numbers. The most obvious difference in fish densities was found between wind-power foundations extending through the entire water column and the surrounding open waters. Fouling assemblages on the vertical foundation surfaces and at the seabed just below differed from those at the seabed further away by having higher coverage of blue mussel (Mytilus edulis) and less algal growth. The results from the present study suggest that the introduction of offshore wind turbines in marine waters could have a positive effect on fish numbers and the presence of sessile invertebrates
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- Andersson, Mathias H, 1976-, et al.
(författare)
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Importance of Using Multiple Sampling Methodologies for Estimating of Fish Community Composition in Offshore Wind Power Construction Areas of the Baltic Sea
- 2007
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Ingår i: Ambio. - 0044-7447 .- 1654-7209. ; 36:8, s. 634-636
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Tidskriftsartikel (refereegranskat)abstract
- It is standard procedure that an Environmental Impact Assessment (EIA) is conducted before larger constructions are built. To adequately describe the impact, methods used in an EIA should be carefully adapted considering both the character of the constructions under development and the environment that will be affected. Various sampling techniques are applied to estimate fish abundances and species composition. Methods used, including trawling, seine and gill netting, angling, echo-sound sampling, fishery data, video recordings, dredging, and visual counts using SCUBA, will all give different estimates of fish community composition.
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