| 1. |
- Andersson, Kerstin, et al.
(författare)
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Effects of biological treatment on the chemical structure of dissolved lignin-related substances in effluent from thermomechanical pulping
- 2008
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 23:2, s. 164-171
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Tidskriftsartikel (refereegranskat)abstract
- Effluent from a TMP-based pulp and paper mill was collected at the inlet and outlet of the mill's biological treatment plant and fractionated by sorption on XAD-8 resin and MTBE precipitation. Fractionation indicated that the refractory dissolved organic material in biologically treated effluent was mainly composed of lignin-related substances. Characterisation of the lignin-related substances by chromatographic and spectrometric methods confirmed the similarities of the isolated material and milled wood lignin. Fractionation and characterisation of alkali-extracted material from solids (biosludge) in biologically treated effluent found evidence of lignin-related material. Results indicated that biological treatment had altered the chemical structure and molar-mass distribution of dissolved lignin-related substances.
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| 2. |
- Andersson, Kerstin I., et al.
(författare)
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Effects of biological treatment on the chemical structure of dissolved lignin-related substances in effluent from thermomechanical pulping
- 2008
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Ingår i: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter GmbH. - 0283-2631 .- 2000-0669. ; 23:2, s. 164-171
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Tidskriftsartikel (refereegranskat)abstract
- Effluent from a TMP-based pulp and paper mill was collected at the inlet and outlet of the mill's biological treatment plant and fractionated by sorption on XAD-8 resin and MTBE precipitation. Fractionation indicated that the refractory dissolved organic material in biologically treated effluent was mainly composed of lignin-related substances. Characterisation of the lignin-related substances by chromatographic and spectrometric methods confirmed the similarities of the isolated material and milled wood lignin. Fractionation and characterisation of alkali-extracted material from solids (biosludge) in biologically treated effluent found evidence of lignin-related material. Results indicated that biological treatment had altered the chemical structure and molar-mass distribution of dissolved lignin-related substances.
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| 3. |
- Dedic, Dina, 1985-
(författare)
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The warship Vasa : A Study of Lignin, Extractives and Acids in the oak wood
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The oak wood timbers of the 17th century Swedish warship Vasa are weak. The weakening has been attributed to cellulose degradation, which is more extensive in the interior of the timbers compared to the surface regions. Further, the mechanism of cellulose degradation was attributed to oxidative reactions involving iron as a catalyst. In this work, the non-cellulosic wood components (lignin and extractives) in the wood of the Vasa have been studied in order to assess the level of degradation possibly caused by oxidative reactions. Because the interior of the wood timbers is more acidic and its cellulose more depolymerized than at the near surface regions, a general study of organic acidand iron concentrations with respect to different depths from the surface was also performed.Characterization of lignin in the wood of the Vasa was done by means of wet chemical degradation (thioacidolysis) and subsequent GC-MS analysis of the degradation products, as well as CP/MAS 13C NMR spectroscopy of the wood. Dry acetone- and water extracts of the wood were analyzed by 13C NMR spectroscopy and MALDI-TOF mass spectroscopy in order to study the presence of gallo- and ellagitannins. No severe lignin degradation and no discernible amounts of hydrolysable tannins in the oak wood of the Vasa were detected, indicating that oxidative reactions are not the primary route to cellulose depolymerization.High amounts of oxalic acid (analyzed by HPIEC) and a low pH have been found in the interior of the wood timbers, supporting acid hydrolysis as the main mechanism of cellulose depolymerization. Analysis of the iron distribution using ICP AES shows that iron is most abundant in the surface of the timbers and decreases as the concentration of oxalic acid increases. Experimental work also shows that some iron species (rust) in the Vasa neutralize oxalic acid, thereby protecting the surface wood from acid hydrolysis.
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| 4. |
- Holmbom, Martin, et al.
(författare)
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Performance-based logistics – an illusive panacea or a concept for the future?
- 2014
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Ingår i: Journal of Manufacturing Technology Management. - 1741-038X .- 1758-7786. ; 25:7, s. 958-979
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Tidskriftsartikel (refereegranskat)abstract
- Purpose– The purpose of this paper is to summarize previously reported benefits, drawbacks and important aspects for implementation of performance-based logistics (PBL), and to identify knowledge gaps.Design/methodology/approach– This is a literature review based on 101 articles. The reviewed articles are relevant to PBL in particular, but also to performance contracting, product-service systems (PSS) and servitization in general. The research method involved database searches, filtering results and reviewing publications.Findings– PBL is a business concept that aims to reduce the customer's total costs for capital-intensive products and increase the supplier's profit. The design of the contract, performance measurements and payment models are important aspects for successful implementation. However, the authors find a reason for concern to be the lack of empirical evidence of the profitability of PBL for the customer and the supplier.Originality/value– This literature review of PBL also includes publications from the related research areas: performance contracting, PSS and servitization. Developing PBL can benefit from results in these research areas.
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| 5. |
- Le Normand, Myriam, et al.
(författare)
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Hot-water extraction and characterization of spruce bark non-cellulosic polysaccharides
- 2012
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Ingår i: Nordic Pulp & Paper Research Journal. - 0283-2631 .- 2000-0669. ; 27:1, s. 18-23
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Tidskriftsartikel (refereegranskat)abstract
- Non-cellulosic polysaccharides (NCP) from bark offer large potential as a class of natural raw materials for functional materials development and production of biochemicals. We have elaborated a process for sequential extraction of NCP from industrial Norway spruce bark using an accelerated solvent extraction (ASE) with water at 100 to 160°C. Carbohydrates, Klason lignin and ash content as well as size-exclusion chromatography (SEC) analyses were performed for all hot-water extracts. NCP were mainly composed of glucose, arabinose and galacturonic acid units which revealed the presence of starch, arabinose-rich hemicelluloses and pectins. In total, the industrial bark of Norway spruce contained up to 20% of NCP which were extracted with pressurized hot water. NCP were mainly extractable at 140°C and started to undergo degradation at higher temperature.
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| 6. |
- Le Normand, Myriam, et al.
(författare)
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HOT-WATER EXTRACTION AND CHARACTERIZATIONOF HEMICELLULOSES AND PECTINS FROM BARK OF NORWAY SPRUCE (PICEA ABIES)
- 2010
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Ingår i: 11th European Workshop on Lignocellulosics and Pulp. ; , s. 243-246
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Bark of Norway spruce (Picea abies) contains 20 to 30% of hemicelluloses and pectins which could be extractedwith pressurized hot water. Hemicelluloses and pectins from the fresh inner bark were extracted with anAccelerated Solvent Extractor (ASE) with water at 100 °C, 140 °C and 160 °C. A large amount of arabinose andgalacturonic acid units in the water extract obtained at 140 °C revealed the presence of arabinans and pectins. Atthis temperature, the extraction of hemicelluloses and pectins was the most effective and generated high-molarmassnon-cellulosic polysaccharides with an average molar mass Mw around 40 kDa. Aromatic substancespresent in the hot-water extract at 140 °C could partly be removed by sorption on DAX-8 polyacrylate resin.
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| 7. |
- Le Normand, Myriam, et al.
(författare)
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Hot-water extracts from the inner bark of Norway spruce with immunomodulating activities
- 2014
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 101:1, s. 699-704
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Tidskriftsartikel (refereegranskat)abstract
- The inner bark of Norway spruce (Picea abies) was sequentially extracted with hot water at 100 degrees C, 140 C and 160 degrees C. The hot-water extracts (IB 100 degrees C, IB 140 degrees C and IB 160 degrees C) contained pectic polysaccharides and showed immunostimulating activities. Structural analyses of their carbohydrate content, including glycosidic linkage analyses, revealed the presence of pectins with a large rhamnogalacturonan RG-I domain ramified with highly-branched arabinans. IB 100 degrees C also contained a large amount of terminal glucosyl residues, indicating the presence of highly substituted polymers. IB 160 degrees C was mainly composed of starch. The hot-water extracts were tested for two biological activities, namely complement fixation and macrophage stimulation. IB 100 degrees C exhibited the highest complement fixation activity, with a 1.7-times higher IC(H)50 than the control pectin, while IB 140 degrees C and IB 160 degrees C gave similar IC(H)50 values as the control. Macrophages were stimulated by IB 100 degrees C and IB 140 degrees C in a dose-dependent manner, but not by IB 160 degrees C. IB 100 degrees C presented the highest activity toward macrophages, comparable to the control pectin.
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| 8. |
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| 9. |
- Salmi, Tapio, et al.
(författare)
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Kinetic modeling of hemicellulose hydrolysis in the presence of homogeneous and heterogeneous catalysts
- 2014
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Ingår i: AIChE Journal. - : John Wiley & Sons. - 0001-1541 .- 1547-5905. ; 60:3, s. 1066-1077
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Tidskriftsartikel (refereegranskat)abstract
- Kinetic models were developed for the hydrolysis of O-acetyl-galactoglucomannan (GGM), a hemicellulose appearing in coniferous trees. Homogeneous and heterogeneous acid catalysts hydrolyze GGM at about 90°C to the monomeric sugars galactose, glucose, and mannose. In the presence of homogeneous catalysts, such as HCl, H2SO4, oxalic acid, and trifluoroacetic acid, the hydrolysis process shows a regular kinetic behavior, while a prominent autocatalytic effect was observed in the presence of heterogeneous cation-exchange catalysts, Amberlyst 15 and Smopex 101. The kinetic models proposed were based on the reactivities of the nonhydrolyzed sugar units and the increase of the rate constant (for heterogeneous catalysts) as the reaction progresses and the degree of polymerization decreases. General kinetic models were derived and special cases of them were considered in detail, by deriving analytical solutions for product distributions. The kinetic parameters, describing the autocatalytic effect were determined by nonlinear regression analysis. The kinetic model described very well the overall kinetics, as well as the product distribution in the hydrolysis of water soluble GGM by homogeneous and heterogeneous catalysts. The modelling principles developed in the work can be in principle applied to hydrolysis of similar hemicelluloses as well as starch and cellulose.© 2014 American Institute of Chemical Engineers AIChE J, 60: 1066–1077, 2014
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| 10. |
- Selinus, Olle, et al.
(författare)
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12. Metal Flows and Environmental Impact
- 2003. - 1
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Ingår i: Environmental Science. - Uppsala : Baltic University Press. - 9197001708 ; , s. 356-383, s. 356-383 of 824
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Bokkapitel (populärvet., debatt m.m.)
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