| 1. |
- Olsson, Maria, 1976, et al.
(författare)
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Specific volatile hydrocarbons in smoke from oxidative pyrolysis of softwood pellets
- 2004
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Ingår i: Journal of Analytical and Applied Pyrolysis. ; 71:2, s. 847-854
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Tidskriftsartikel (refereegranskat)abstract
- Samples of smoke from laboratory burning of commercial sawdust-based softwood pellets were analysed by gas chromatography on an aluminium oxide column. Flaming burning was very efficient. Significant emitted hydrocarbons were methane, quantitatively followed by ethene and lower proportions of ethane, ethyne and propene. The even lower hydrocarbon emissions from final glowing combustion were strikingly different with ethyne and benzene as the only prominent non-methane hydrocarbons. Smouldering combustion caused much higher hydrocarbon concentrations. Prominent non-methane compounds were furan and ethene from initial smouldering, and ethane, ethene and benzene from after-flame smouldering. The large differences in the proportions of specific hydrocarbons should be considered in evaluations of emissions from residential burning of pellets, with respect to combustion technology and impact on environment and health.
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| 2. |
- Olsson, Maria, 1976, et al.
(författare)
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Benzene emitted from glowing charcoal
- 2003
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Ingår i: The Science of The Total Environment. ; 303:3, s. 215-220
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Tidskriftsartikel (refereegranskat)abstract
- Benzene was assessed as the predominant aromatic compound emitted from glowing charcoal and firewood embers. Concentrations measured above charcoal used for grilling exceeded 10 mg m?3 at a 5% carbon dioxide level. Charcoal with a high carbon content released less benzene. Glowing wood pellets emitted less benzene than glowing firewood remainders. The emissions of ethene and propene relative to benzene were low for commercial charcoal and wood-pellet embers, but high for firewood ember. The proportions of methylbenzene and naphthalene from charcoal were typically only 10% relative to benzene, and those of benzofuran, dibenzofuran and benzonitrile were typically below 5%. The polycyclic aromatic hydrocarbon (PAH) indicator phenanthrene was below the 1% level. Adsorbent sampling and GC-MS were used for assessing all the aromatic compounds. Earlier studies of charcoal emissions have focused on carbon monoxide, PAH and dioxins. It is concluded that the carcinogenic benzene may be an even more severe health hazard to be addressed by exposure-decreasing measures.
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| 3. |
- Olsson, Maria, 1976, et al.
(författare)
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Oxidative pyrolysis of integral softwood pellets
- 2003
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Ingår i: The Journal of Analytical and Applied Pyrolysis. ; 67:1, s. 135-141
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Tidskriftsartikel (refereegranskat)abstract
- Commercial wood pellets are increasingly used for residential heating. Characterisations were made of smoke components from oxidative pyrolysis of softwood pellets from compressed sawdust and wood shavings. Specific compounds released by flaming and glowing laboratory burning were sampled on Tenax cartridges and assessed by gas chromatography and mass spectrometry. Six lignin-related 2-methoxyphenols with antioxidant properties, together with 1,6-anhydroglucose from cellulose, were the major primary semi-volatile compounds released during flaming burning. Glowing combustion released benzene as the predominant aromatic compound.
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| 4. |
- Olsson, Maria, 1976, et al.
(författare)
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Specific chimney emissions and biofuel characteristics of softwood pellets for residential heating in Sweden
- 2003
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Ingår i: Biomass and Bioenergy. ; 24:1, s. 51-57
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Tidskriftsartikel (refereegranskat)abstract
- Softwood pellets are mainly produced from sawdust and to some extent from wood shavings. The moisture content is typically less than half of that in firewood. The present annual residential use in Sweden for pellet burners in boilers and for pellet stoves amounts to more than 100 000 tonnes and is increasing rapidly. The total annual production capacity at the more than 20 units exceeds one million tonnes, and permits continued rapid replacement of firewood and petroleum oil for residential heating.With the purpose of characterising emissions to air, chimney smoke was sampled, and specific compounds were assessed by gas chromatography and mass spectrometry. Benzene was the predominant aromatic compound in emissions from pellet burners. The smoke from stoves contained methoxyphenols with antioxidant properties and lower proportions of aromatic hydrocarbons. Observed differences in emissions from specific burning appliances are of interest with regard to both health hazards and regulation of emissions.Consideration of ecological aspects and pollution hazards indicates that wood pellets should be used primarily for residential heating, whereas controlled large-scale combustion is preferable for most other types of biomass waste.
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| 5. |
- Kjällstrand, Jennica, 1974, et al.
(författare)
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Phenolic antioxidants in alder smoke during industrial meat curing
- 2001
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Ingår i: Food Chemistry. ; 74, s. 85-89
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Tidskriftsartikel (refereegranskat)abstract
- Alder wood smoke in a large sausage-curing chamber was analysed with regard to its content of methoxyphenol antioxidants. The use of Tenax adsorbent cartridges permitted simultaneous quantitative sampling of phenols condensed on smoke particles as well as gaseous compounds. The analytical determinations were performed by thermal desorption combined with gas chromatography and mass spectrometry. In addition to methoxyphenols, several other key components were assessed, including 1,6-anhydroglucose, 2-furaldehyde, furans and hydrocarbons. Benzene was the most prominent hydrocarbon. The concentrations of polycyclic aromatic compounds were low, due to a low smoke generation temperature. Predominant smoke components were the 2,6-dimethoxyphenols, which are characteristic thermal degradation products from hardwood. The 2,6-dimethoxyphenols are stronger antioxidants than the 2-methoxyphenols present in lower amounts. The particularly active antioxidants with a 4-alkenyl side-chain constituted 20-30% of total methoxyphenols, which is much more than normally reported for liquid smoke. The phenolic antioxidants may be important not only for the preservation of foods, but also for health as dietary components.
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| 6. |
- Kjällstrand, Jennica, 1974, et al.
(författare)
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Phenolic antioxidants in wood smoke
- 2001
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Ingår i: The science of the total environment. ; 277, s. 69-75
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Tidskriftsartikel (refereegranskat)abstract
- Ten prominent dimethoxyphenols were determined in birchwood smoke from choked and open laboratory burning and in chimney smoke from a tiled stove. The structures of the methoxyphenols are similar to those of the well-known tocopherol and ubiquinol antioxidants. The 2,6-dimethoxyphenols characterising hardwood smoke are stronger antioxidants than the corresponding 2-methoxyphenols present mainly in softwood smoke. The antioxidant activity is highest for the 2,6-dimethoxyphenols with 4-alkenyl and 4-alkyl groups, which constitute 60-70% of the total amount of dimethoxyphenols. Phenolic antioxidants are scavengers of oxygen radicals and should be considered when health hazards of small-scale incomplete biomass burning are estimated.
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| 7. |
- Kjällstrand, Jennica, 1974, et al.
(författare)
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Phenols and aromatic hydrocarbons in chimney emissions from traditional and modern residential wood burning
- 2001
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Ingår i: Environmental Technology. ; 22, s. 391-395
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Tidskriftsartikel (refereegranskat)abstract
- The emissions from a traditional tiled stove consisted mainly of lignin-related methoxyphenols with antioxidant properties, and 1,6-anhydroglucose from cellulose degradation. A wood stove of presently introduced energy-efficient design for residential heating and hot-water supply was shown to emit small amounts of methoxyphenols and anhydrosugars from primary wood pyrolysis. Secondary harmful components like benzene and polycyclic aromatic hydrocarbons constituted a major portion of the organic emissions. It is concluded that differences in smoke composition are essential to consider in recommendations and rules for proper choices of wood burning devices.
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| 8. |
- Kjällstrand, Jennica, 1974, et al.
(författare)
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Coniferyl alcohol from newsprint burning
- 2000
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Ingår i: Nordic pulp and paper journal. ; 15, s. 98-100
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Tidskriftsartikel (refereegranskat)abstract
- Coniferyl alcohol constitutes almost half of the amount of methoxyphenols in smoke from choked burning of newsprint produced from thermomechanical pulp. The results indicate that coniferyl alcohol is a key component not only in biosynthesis but also in thermal decomposition of lignin. The trans isomer was formed in 5-10 times larger amounts than the cis isomer. Coniferyl alcohol and the oxidised analogue coniferaldehyde were also shown to be the most prominent methoxyphenols in chimney smoke from stove burning of newsprint.
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| 9. |
- Kjällstrand, Jennica, 1974, et al.
(författare)
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Methoxyphenols from burning of Scandinavian forest plant materials
- 2000
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Ingår i: Chemosphere. ; 41, s. 735-741
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Tidskriftsartikel (refereegranskat)abstract
- Semivolatile compounds in smoke from gram-scale incomplete burning of plant materials were assessed by gas chromatography and mass spectrometry. Gas syringe sampling was shown to be adequate by comparison with adsorbent sampling. Methoxyphenols as well as 1,6-anhydroglucose were released in amounts as large as 10 mg kg(-1) of dry biomass at 90% combustion efficiency. Wood, twigs, bark and needles from the conifers Norway spruce and Scots pine emitted 12 reported 2-methoxyphenols in similar proportions. Grass, heather and birchwood released the same 2-methoxyphenols but also the corresponding 2,6-dimethoxyphenols which are characteristic of angiosperms. The methoxyphenols are formed from lignin and differ in structure by the group in para position relative to the phenolic OH group. Prominent phenols were those with trans-1-propenyl and ethenyl groups in that position. Vanillin, 4-hydroxy-3-methoxybenzaldehyde, was a prominent carbonyl compound from the conifer materials.
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