| 1. |
- Antti, Lena, et al.
(författare)
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Effects of microwave drying on biomass fatty acid composition and fuel pellet quality
- 2011
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Ingår i: Wood Material Science & Engineering. - : Informa UK Limited. - 1748-0272 .- 1748-0280. ; 6:1-2, s. 34-40
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Tidskriftsartikel (refereegranskat)abstract
- Drying of biomass for fuel pellet production is a time- and energy-consuming process. The objective of this study was to investigate not only whether microwave drying could be an alternative drying method but also whether the microwave treatment brings beneficial chemical properties into the biomass feedstock in terms of, for example, fatty acid composition and, further, whether this could be advantageous in the production of wood pellets. Microwave drying tests were conducted using fresh sawdust from pinewood as a biomass model. In these tests sawdust was dried from weight-based moisture content 0.47 to final moisture contents in the interval 0.08-0.14. The chemical composition, pellet-making and mechanical properties of the pellets were then investigated. It was shown that 0.5 kg sawdust could be dried within 40 min of microwave exposure. The effects of microwave treatment on the fatty and resin acid composition indicated that some changes occurred, but the total amounts were not significantly different from those in oven-dried samples. However, the microwave treatment of sawdust significantly improved pellet density and pellet strength. These results indicate new possibilities to alter fatty and resin acid composition and to improve particle bonding within fuel pellets.
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| 2. |
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| 3. |
- Blomqvist, Johanna, et al.
(författare)
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Temperature-dependent changes in the microbial storage flora of birch and spruce sawdust
- 2014
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Ingår i: Biotechnology and Applied Biochemistry. - : Wiley. - 0885-4513 .- 1470-8744. ; 61, s. 58-64
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Tidskriftsartikel (refereegranskat)abstract
- Sawdust can be used to make pellets (biofuel) and particle boards and as a potential lignocellulose feedstock in bioethanol production. Microbial activity can affect sawdust quality; hence, we monitored the microbial population in birch- and spruce sawdust after 3 months' storage at various temperatures. Species composition was similar on both materials but was strongly influenced by temperature. Bacteria were present on all materials at all conditions: on birch, 2.8x10(8), 1.1x10(8), and 8.8x10(6), and on spruce, 4.1x10(8), 5.6x10(7), and 1.5x10(8)CFU/g DM, at 2, 20, and 37 degrees C, respectively. Dominant bacteria at 2, 20, and 37 degrees C were Pseudomonas spp. (some Enterobacteriaceae spp. present), Luteibacter rhizovicinus, and Fulvimonas sp., respectively. Pseudomonas spp. were absent at 20 degrees C. Among microfungi, yeasts dominated at 2 degrees C but were absent at 37 degrees C, whereas molds dominated at 20 and 37 degrees C. Common yeasts included Cystofilobasidium capitatum, Cystofilobasidium infirmominiatum, Candida saitoana, Candida oregonensis, and Candida railenensis. Ophiostoma quercus was a common mold at 2 and 20 degrees C, whereas the human pathogens Aspergillus fumigatus and Paecilomyces variotii dominated at 37 degrees C. Attempts to influence the microflora by addition of the biocontrol yeasts, Wickerhamomyces anomalus and Scheffersomyces stipitis, were unsuccessful, as their growth in sawdust was poor to absent.
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| 4. |
- Chen, Feng, et al.
(författare)
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Shiitake cultivation as biological preprocessing of lignocellulosic feedstocks – Substrate changes in crystallinity, syringyl/guaiacyl lignin and degradation-derived by-products
- 2022
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Ingår i: Bioresource Technology. - : Elsevier. - 0960-8524 .- 1873-2976. ; 344:Part B
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Tidskriftsartikel (refereegranskat)abstract
- Formulation of substrates based on three hardwood species combined with modulation of nitrogen content by whey addition (0–2%) was investigated in an experiment designed in D-optimal model for their effects on biological preproceesing of lignocellulosic feedstock by shiitake mushroom (Lentinula edodes) cultivation. Nitrogen loading was shown a more significant role than wood species for both mushroom production and lignocellulose degradation. The fastest mycelial colonisation occurred with no nitrogen supplementation, but the highest mushroom yields were achieved when 1% whey was added. Low nitrogen content resulted in increased delignification and minimal glucan consumption. Delignification was correlated with degradation of syringyl lignin unit, as indicated by a significant reduction (41.5%) of the syringyl-to-guaiacyl ratio after cultivation. No significant changes in substrate crystallinity were observed. The formation of furan aldehydes and aliphatic acids was negligible during the pasteurisation and fungal cultivation, while the content of soluble phenolics increased up to seven-fold.
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| 5. |
- Eriksson, D., et al.
(författare)
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Characterization of Scots pine stump-root biomass as feed-stock for gasification
- 2012
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 104, s. 729-736
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Tidskriftsartikel (refereegranskat)abstract
- The main objective was to explore the potential for gasifying Scots pine stump-root biomass (SRB). Washed thin roots, coarse roots, stump heartwood and stump sapwood were characterized (solid wood, milling and powder characteristics) before and during industrial processing. Non-slagging gasification of the SRB fuels and a reference stem wood was successful, and the gasification parameters (synthesis gas and bottom ash characteristics) were similar. However, the heartwood fuel had high levels of extractives (≈19%) compared to the other fuels (2-8%) and thereby ≈16% higher energy contents but caused disturbances during milling, storage, feeding and gasification. SRB fuels could be sorted automatically according to their extractives and moisture contents using near-infrared spectroscopy, and their amounts and quality in forests can be predicted using routinely collected stand data, biomass functions and drill core analyses. Thus, SRB gasification has great potential and the proposed characterizations exploit it. © 2011 Elsevier Ltd.
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| 6. |
- Finell, Michael, et al.
(författare)
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Laboratory-scale production of biofuel pellets from electron beam treated Scots pine (Pinus silvestris L.) sawdust
- 2009
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Ingår i: Radiation Physics and Chemistry. - : Elsevier BV. - 0969-806X. ; 78, s. 281-287
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Tidskriftsartikel (refereegranskat)abstract
- The effect of electron beam (EB) treatment on pine sawdust used as raw material for fuel pellets was studied. Dry sawdust was EB treated at different dosage levels up to 100 kGy. The effect of EB treatment on fatty and resin acid composition was studied for different dosage levels and compared to untreated sawdust. Pellets were pressed in a laboratory single pellet press unit according to a D-optimal, response surface modeling (RSM) experimental design, where sawdust moisture content and die temperature were varied independently for EB treatment dosages of 0, 18.2 and 48.9 kGy. The responses of the designed experiment were density and strength for the produced pellets. The results showed that the free fatty and resin acid content in the sawdust initially decreased with increasing EB doses but at the highest EB doses it increased. The total content of extractives however initially increased and then decreased with increasing EB dose. Pellets made of EB treated sawdust had a significantly (at 95% confidence level) higher density and compressive strength than pellets made from untreated sawdust. EB treated sawdust behaved similarly to stored (mature) sawdust as a pellet raw material. Thus, EB treatment opens the possibility for controlled ageing (maturation) of pellet raw materials.
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| 7. |
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| 8. |
- Geladi, Paul, et al.
(författare)
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Biomass properties in association with plant species and assortments. II: A synthesis based on literature data for ash elements
- 2012
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Ingår i: Renewable and Sustainable Energy Reviews. - : Elsevier BV. - 1364-0321. ; 16, s. 3507-3522
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Tidskriftsartikel (refereegranskat)abstract
- A study was carried out based on ash composition data (relative proportion of SiO2, K2O, CaO, MgO, Na2O, P2O5, Al2O3, Fe2O3 and SO2 in ash) in a large number of biomass species and assortments. The data were collected from 109 peer-reviewed publications and consisted of 367 objects for ash composition analysis. Principal component analysis (PCA) was used to analyze the data. The analyses were performed at five levels of plant classifications respectively: level 1-3 for lifeforms/species groups, level 4 for assortments and level 5 for species. Woody species data points tended to differ from herbaceous ones in terms of PCA for level 1 analysis. The loading plot of the two first components (PC1 and PC2) indicated that the woody species tended to be associated with Ca-Mg-P-K-S, while the herbaceous ones were closer to Si. Ca and Si had the largest contributions in forming the pattern. The woody group had a larger variation than the herbaceous group in terms of ash composition but this could be explained only by differentiation in assortments as illustrated with the level 4 analysis. The PCA analyses at levels 2 and 3 did not generate significant patterns, as the variations within the groups were larger than between the groups. The variation of the herbaceous data, however, could be explained by all level 2-5 analyses and attributed to differences between herbaceous dicots and graminoids, between C3 and C4 plants, and between assortments such as husk, fruit residues and bagasse. The robust analysis had in general the same results. These results could be further interpreted by the trend that Si decreased but Ca increased gradually in the following order: C3 graminoids -> C4 graminoids -> herbaceous dicots -> woody groups. It was also found that K, P, Mg and S were higher in herbaceous dicots than in graminoids
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| 9. |
- Geladi, Paul, et al.
(författare)
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Chemometrics in spectroscopy : Part 2. Examples
- 2004
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Ingår i: SPECTROCHIMICA ACTA PART B-ATOMIC SPECTROSCOPY. - : Elsevier BV. - 0584-8547. ; 59:9, s. 1347-57
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Tidskriftsartikel (refereegranskat)abstract
- Some of the principles and main methods of chemometrics are illustrated by examples. The examples are from electrochemistry, process analytical chemistry and multivariate imaging. Principal component analysis, partial least squares regression and multivariate image analysis are used to illustrate the power of chemometrical thinking. The emphasis is on plotting and visualization for showing the salient features of a model or data set.
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| 10. |
- Hedayati, Ali, 1984-, et al.
(författare)
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Fate of phosphorus and potassium in single-pellet thermal conversion of forest residues with a focus on the char composition
- 2021
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Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 150
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Tidskriftsartikel (refereegranskat)abstract
- The phosphorus and potassium contents of the char obtained from thermal conversion of forest residues can limit its utilization as an alternative fuel and reducing agent to substitute coal/coke in the steelmaking industry. In this study, ash transformation and release of K and P during single-pellet thermal conversion of different types of forest residues (i.e., bark, twigs, and bark+twigs) were investigated with the aid of a vertical tube furnace (Macro-TGA) at different temperatures (i.e., 600, 800, and 950 °C) and within and after different fuel conversion stages, i.e., devolatilization and char gasification. The residual char before and after full devolatilization, and ash after char gasification were characterized by SEM-EDS, XRD, and ICP-OES with the support of thermochemical equilibrium calculations. The concentrations of K (7970–19500 mg/kg) and P (1440–4925 mg/kg) in the char produced after devolatilization were more than four times higher than in coke and pulverized coal frequently used in metallurgical processes. A low amount of P and K (≤15%) were released from all fuels. K and P were evenly distributed within the char residues, and no crystalline compounds containing K and P were found. In ash residues of bark, K was found in K2Ca2(CO3)3, and K2Ca(CO3)2. K in ash residues from twigs and bark+twigs was mainly found in the amorphous part of ash, most likely in the form of K-Ca rich silicates. Apatite was found as the main P crystalline compound in all ashes at all temperatures. Estimations show that a release of more than 80% is needed for the studied forest residual assortments to reach K and P concentrations typical of blast furnace coals and cokes.
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| 11. |
- Jogi, Ramakrishna, et al.
(författare)
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Biocrude production through hydro‐liquefaction of wood biomass in supercritical ethanol using iron silica and iron Beta zeolite catalysts
- 2019
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Ingår i: Journal of chemical technology and biotechnology (1986). - : John Wiley & Sons. - 0268-2575 .- 1097-4660. ; 94:11, s. 3736-3744
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In the production of biofuels from lignocellulosic material, biocrude plays a key role. The present work deals with the biocrude production through hydrothermal liquefaction (HTL) of birch wood in supercritical ethanol over 5 wt. % Fe‐H‐Beta‐150 (SiO2 to Al2O3 ratio of 150) or 5 wt. % Fe‐SiO2 catalyst.RESULTS: The liquid and solid products were characterized with various analytical techniques such as GC‐MS, GC‐FID, SEC, ICP‐MS, p‐XRD, SEM, and solid‐state 13C MAS NMR respectively. The results revealed that 5 wt. % Fe‐H‐Beta‐150, a strongly Brønsted acidic catalyst, enhanced the biocrude formation when compared with a non‐acidic 5 wt. % Fe‐SiO2 catalyst. Hemicellulose and lignin degradation occurred resulting in formation of mainly sugars, acids‐esters and phenolic compounds in liquid phase. The gaseous atmosphere of hydrogen also enhanced the degradation of biomass. The biocrude yield from birch was 25 wt. % over 5 wt. % Fe‐H‐Beta‐150. The Brønsted acidic catalyst gave higher dissolution efficiency and its clear catalytic effect was observed in comparison to non‐acidic 5 wt. % Fe‐SiO2. The degradation level of lignin in presence of 5 wt. % Fe‐H‐Beta‐150 was high 68 wt. % aromatic products were formed, while only 38 wt. % was obtained with 5 wt. % Fe‐SiO2.CONCLUSIONS: Hydrogen atmosphere enhances the fractionation of birch wood when compared to argon atmosphere. 5 wt. % Fe‐H‐Beta‐150 catalyst enhanced very strongly the degradation of hemicellulose and lignin in biomass to sugars and acid‐esters as well as phenolic compounds, respectively compared to the non‐acidic 5 wt. % Fe‐SiO2 catalyst.
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| 12. |
- Jogi, Ramakrishna, et al.
(författare)
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Liquefaction of Lignocellulosic Biomass into Phenolic Monomers and Dimers Over Multifunctional Pd/Nbopo4 Catalyst
- 2022
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Ingår i: SSRN Electronic Journal. - : Elsevier BV. - 1556-5068.
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- For the first time, a tandem catalytic material namely 5 wt. % Pd/NbOPO 4 was utilized in the depolymerization of wood in supercritical-ethanol under low initial-hydrogen pressure. The experiments were conducted under various experimental conditions, wood fractionation was executed with fresh, and acetone extracted birch. A comprehensive analysis was performed to elucidate the dissolution efficiency and achieved product distribution. The results indicated fresh birch, 34 wt. % of lignin monomer yield with 84 wt. % delignification efficiency were obtained while extracted wood, 35 wt. % of lignin monomer yield with 78 wt. % delignification efficiency was achieved. The total lignin monomer content extracted from the fresh birch is composed of 76.9 wt. % of dimethoxyphenols and 16.5 wt. % of monomers with the guaiacol structure. Among the dimethoxyphenols, major homosyringaldehyde (61.9 wt. %). Where extracted wood, 93.2 wt. % of dimethoxyphenols (63.6 wt. % homosyringaldehyde) and guaiacol-monomers (6.8 wt. %). It was concluded that the depolymerization occurred via breaking of the ether bonds in lignin, including ether hydrolysis by Lewis acid sites over the solid acid catalyst and with subsequent deoxygenation of monophenols over Pd. In addition, an extraction process was proposed to extract the aromatic fraction from the obtained biocrude.
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| 13. |
- Jogi, Ramakrishna, et al.
(författare)
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Liquefaction of lignocellulosic biomass into phenolic monomers and dimers over multifunctional Pd/NbOPO4 catalyst
- 2024
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682.
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Tidskriftsartikel (refereegranskat)abstract
- For the first time, a tandem catalytic material, 5 wt. % Pd/NbOPO4, was utilized in the depolymerization of wood in supercritical ethanol under hydrogen atmosphere. The experiments were conducted under various conditions, with fresh, and acetone extracted birch. A comprehensive analysis was performed to elucidate the dissolution efficiency and achieved product distribution. The results indicated that with fresh birch, 34 wt. % of lignin monomer yield with 84 wt. % delignification efficiency were obtained while with extracted wood, 35 wt. % of lignin monomer yield with 78 wt. % delignification efficiency were achieved. The total lignin monomer content extracted from the fresh birch is composed of 76.9 wt. % of dimethoxyphenols and 16.5 wt. % with the guaiacol structure. Major lignin monomer product was homosyringaldehyde (61.9 wt. %). With extracted wood, 93.2 wt. % of dimethoxyphenols (63.6 wt. % homosyringaldehyde) and 6.8 wt. % of guaiacol-monomers were achieved. It was concluded that the depolymerization occurred via breaking of the ether bonds in lignin, including ether hydrolysis by Lewis acid sites over the solid acid catalyst and with subsequent deoxygenation of monophenols over Pd. In addition, an extraction process was proposed to extract the aromatic fraction from the obtained biocrude.
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| 14. |
- Jogi, Ramakrishna, et al.
(författare)
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Understanding the formation of phenolic monomers during fractionation of birch wood under supercritical ethanol over iron based catalysts
- 2020
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Ingår i: Journal of the Energy Institute. - : Elsevier. - 1743-9671 .- 1746-0220. ; 93:5, s. 2055-2062
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Tidskriftsartikel (refereegranskat)abstract
- The liquefaction of biomass in ethanol, at the critical point, has high potential due to low temperature and pressure (243 °C, 63 bar) when compared with water (374 °C, 220 bar). The current study deals with the fractionation of birch wood powder which was liquefied under supercritical ethanol over acidic or non-acidic catalysts, 5 wt % Fe-Beta-H-150 and 5 wt % Fe–SiO2, respectively. Based on the results, the reaction mechanism for the formation of lignin degradation products was proposed. The main phenolic product was isoeugenol over 5 wt % Fe-Beta-H-150 while intermediate products, i.e. such as coniferyl, and sinapyl alcohol, 4-propenyl syringol, syringaresinol, as well as syringyldehyde reacted rapidly further. The thermodynamic analysis was performed by Joback approach and using Gibbs-Helmholtz equation supporting the obtained results.
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| 15. |
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| 16. |
- Larsson, Sylvia, et al.
(författare)
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Assessment on bulk solids best practice techniques for flow characterization and storage/handling equipment design for biomass materials of different classes
- 2015
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Ingår i: Fuel Processing Technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 138, s. 540-554
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Tidskriftsartikel (refereegranskat)abstract
- This paper shows the results of a collaborative project in which four different laboratories have carried out complementary characterization tests on samples of the same set of lignocellulosic biomass materials with the objectives of better understanding their properties and identifying any critical features of the different characterization procedures. Three different types of material were used as model biomasses: 1) Scots pine wood chips, as an example of a coarse and flaky particulate biomass with some elastic properties; 2) chopped straw of reed canary grass as a nesting biomass having long and flaky fibers; and 3) Scots pine wood powder as a fine particulate with elastic and cohesive properties. Particle size and shape analyses were carried out with; calipers, 2D image analysis, 3D image analysis (ScanChip) and through mechanical sieving. Applications and validity limits of each of these techniques are evaluated and discussed. The flowfunction and internal friction were determined with a Schulze ring shear tester, a Brookfield powder flow tester and a large ring shear tester. No significant differences in the results generated by these shear testing techniques were found. Wall friction measurements were carried out with a Schulze ring shear tester; a Brookfield powder flow tester; a large Jenike shear tester and a Casagrande shear box. Results, in this case, showed significant differences with a higher wall friction coefficient obtained with the larger shear cell. Additionally, tensile strengths of biomass materials were measured by the use of a novel measurement technique. Arching tests were carried out in a pilot scale plane silo with variable hopper geometry and results were compared with those predicted by applying the Jenike procedure and a modified procedure which assumed that tensile strength was the controllingmaterial property (rather than unconfined yield strength). Finally, safety of handling and storage was assessed by carrying out explosion tests on dusts from Scots pine and reed canary grass.
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| 17. |
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| 18. |
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| 19. |
- Larsson, Sylvia, et al.
(författare)
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Fuel pellets from lodge pole pine first thinnings
- 2012
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Stemwood and whole trees of lodgepole pine (Pinus contorta Dougl. var. latifolia L.) were evaluated asraw materials for fuel pellets in a pilot scale pelletizing study. Pellet and pelletizing properties were measured andmodeled in an experimental design where raw material moisture content (%), die channel length (mm), and storage time(days) were varied. Additionally, ash contents (%), extractive contents (%), and ash melting temperatures (°C) wereanalyzed. For both assortments, raw material moisture content was positively correlated to pellet bulk density anddurability (range 9-13%, wet base). Both assortments had ash contents below 0.7%, and thus, fulfilled the demands forclass A1 pellets.
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| 20. |
- Larsson, Sylvia, et al.
(författare)
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Temperature controlled feed layer formation in biofuel pellet production
- 2012
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 94, s. 81-85
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Tidskriftsartikel (refereegranskat)abstract
- A pilot scale pelletizing system (capacity: 300 kg/h) with integrated die temperature control was built and evaluated using reed canary grass as a model raw material. A pelletizing series was performed using a full factorial design having independent factors such as die temperature (35-65 C), raw material moisture content (12-15% w.b.), and raw material temperature/steam conditioning (0-2 kg/h), with continuous or discontinuous feed layer formation as responses. Die temperature was the most influential parameter on feed layer formation and was negatively correlated to continuous feed layer formation. An immediate response, changing discontinuous production patterns into continuous was experienced when die temperature was lowered by the temperature control system. Further, a partial least squares discriminant analysis model, using the experimentally varied parameters, predicted continuous or discontinuous feed layer formation with 100% accuracy. Thus, die temperature control can be considered as a fast and efficient method for overcoming feed layer losses in pelletizing.
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| 21. |
- Larsson, Sylvia, et al.
(författare)
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Temperature patterns in large scale wood pellet silo storage
- 2012
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 92, s. 322-327
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Tidskriftsartikel (refereegranskat)abstract
- Over a 7 month period, temperatures were monitored in six large scale (approximately 4500 metric tons) silos for wood pellet storage. Each silo had 124 temperature sensors mounted on cables for an even distribution within the volume. During the study, silos were charged and discharged several times, creating different scenarios. Under certain circumstances, pellet temperatures increased vertically from bottom to top in an additive way, and temperatures around 65-70 degrees C were reached at the top of the silos. At some occasions, temperatures were increasing uncontrollably and silos were emptied due to the risk of fire. In an additive scenario, a maximum heat front velocity of 12 cm/h and a maximum temperature increment for a specific sensor of 2.4 degrees C/h was found. To avoid condensation of moisture from the ventilation air on stored pellets fan operation is suggested to be controlled by a dew point algorithm. (C) 2011 Elsevier Ltd. All rights reserved.
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| 22. |
- Lestander, Torbjörn A., et al.
(författare)
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Prediction of Pinus sylvestris clear-wood properties using NIR spectroscopy and biorthogonal partial least squares regression
- 2008
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Ingår i: Canadian Journal of Forest Research. - 0045-5067 .- 1208-6037. ; 38, s. 2052-2062
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Tidskriftsartikel (refereegranskat)abstract
- Thirteen wood parameters were predicted using near infrared (NIR) spectra in the range 780-2380 nm modelled by biorthogonal partial least squares regression. The analysis of parameters and NIR measurements was done on clear-wood samples from the base and midstem of Scots pine (Pinus sylvestris L.) from trees at two sites. Calibrations based oil the measured parameters at seven growth rings (cambial age ranging between 6 and 42 years) could be divided into three groups: (i) the best accuracy was found for longitudinal modulus of elasticity (r > 0.9) followed by bending, compression, and cell length (0.8 < r < 0.9); (ii) microfibril angle, longitudinal hardness, proportion of latewood, and creep with correlations in the range of 0.7-0.8; and (iii) tangential hardness, cell diameter, and cell wall thickness with 0.4 < r < 0.7. It was also shown that juvenile (cambial age : 20 years) and mature wood can be classified using NIR techniques.
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| 23. |
- Lestander, Torbjörn, et al.
(författare)
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Assessment of biomass functions for calculating bark proportions and ash contents of refined biomass fuels derived from major boreal tree species
- 2012
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Ingår i: Canadian Journal of Forest Research. - 0045-5067 .- 1208-6037. ; 42, s. 58-66
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of the components of above-ground biomass of low-quality stems harvested to produce biofuel pellets is important, since bark has higher ash contents (a key quality parameter for the pellets) than wood. Therefore, single-tree biomass functions by Marklund (1988. Rep. 45. Department of Forest Survey, Swedish University of Agricultural Sciences, Umea, Sweden.) were evaluated using a sample population of 1612 Scots pine (Pinus sylvestris L.), Norway spruce (Pices abies (L.) Karst.), and birch (Betula pendula Roth and Betula pubescens Ehrh.) trees and three methods to model bark proportions. Bark percentages calculated subtractively using functions for stem biomass over and under bark showed anomalous patterns, especially for pine and birch. However, additive use of biomass functions for bark biomass and stem biomass under bark resulted in similar patterns to bark percentages traditionally calculated from bark biomass and stem biomass over bark. Published ash contents of bark and stemwood indicate that pine, birch, and spruce stems with breast height (1.3 m) diameters of 4–40, 4–30, and >19 cm, respectively, have <0.7% ash contents (the current limit for the highest quality fuel pellets). However, if the highest recorded ash contents are used, only pine stems meet this criterion. Thus, material of different species and stem dimensions may need to be carefully mixed when whole-stem biomass is used as feedstock for pelletizing
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| 24. |
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| 25. |
- Lestander, Torbjörn, et al.
(författare)
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Cassava stems: a new resource to increase food and fuel production
- 2015
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Ingår i: GCB Bioenergy. - : Wiley. - 1757-1693 .- 1757-1707. ; 7, s. 72-83
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Tidskriftsartikel (refereegranskat)abstract
- Given the growing global population, mankind must find new ways to lower competition for land between food and fuel production. Our findings for cassava suggest that this important crop can substantially increase the combined production of both food and fuel. Cassava stems have previously been overlooked in starch and energy production. These food-crop residues contain about 30% starch (dry mass) mostly in the xylem rather than phloem tissue. Up to 15% starch of the stem dry mass can be extracted using simple water-based techniques, potentially leading to an 87% increase in global cassava starch production. The integration of biofuel production, using residues and wastewater from starch extraction, may bring added value. The cassava roots on which biofuels and other products are based can be replaced by cassava stems without land use expansion, making root starch available as food for additional 30 million people today.
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| 26. |
- Lestander, Torbjörn, et al.
(författare)
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Characterization of fast pyrolysis bio-oil properties by near-infrared spectroscopic data
- 2018
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 133, s. 9-15
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Tidskriftsartikel (refereegranskat)abstract
- Pyrolysis transforms bulky and heterogeneous lignocellulosic biomass into more easily-handled oils that can be upgraded into bio-based transportation fuels. Existing systems for monitoring pyrolysis processes and characterizing their products rely on slow and time-consuming wet chemical analyses. On-line near-infrared (NIR) spectroscopy could potentially replace such analyses, providing real-time data and reducing costs. To test the usefulness of NIR methods in characterizing pyrolysis oils and processes, biomass from conifers, Salix, and reed canary grass was milled and pyrolyzed at 675, 750, and 775 °C. Two separate pyrolytic fractions (aerosol and condensed) were produced in each experiment, and NIR spectra were collected for each fraction. Multivariate modelling of the resulting data clearly showed that the samples’ NIR spectra could be used to accurately predict important properties of the pyrolysis oils such as their energy values, main organic element (C, H and O) contents, and water content. The spectra also contained predictive information on the samples’ origins, fraction, and temperature treatment, demonstrating the potential of on-line NIR techniques for monitoring pyrolytic production processes and characterizing important properties of pyrolytic oils from lignocellulosic biomass.
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| 27. |
- Lestander, Torbjörn
(författare)
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Chemical composition of biomass
- 2013
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Ingår i: Biomass as energy sources, systems and applications: resources, systems and applications. - 9780415620871 ; :3, s. 35-56
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Bokkapitel (refereegranskat)
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| 28. |
- Lestander, Torbjörn
(författare)
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Fuel pellet breakage in pneumatic transport and durability tests
- 2020
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Ingår i: Renewable Energy. - : Elsevier BV. - 0960-1481. ; 157, s. 911-919
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Tidskriftsartikel (refereegranskat)abstract
- Wood pellets for biofuel utilization are fragile and produce fines and dust when handled. Impact resistances of pellets were obtained by using tumbling box tester, ligno tester and rotary impact tester. The samples were sieved after each of the ten consecutive runs to generate a breakage vector of particle size classes: 0-1.00, 1.00-2.36, 2.36-3.15, 3.15-4.75 and > 4.75 mm. Similarly, a full-scale pneumatic blow wood pellets degradation experiment was conducted.The pellets were blown at different delivery pressures from 0.3 to 1 bars. The breakage patterns disclosed two independent mechanisms when analysed by multivariate modelling: surface breakage by the tumbling box and volume breakage by the rotary impact tester. The combination of these testers can describe the full outcome space for the pneumatic tests and it is possible to predict generation of fines and dust during pneumatic loading of wood pellets from a silo. The most severe damages corresponded to more than 10 times 500 revolutions in a tumbling box and 8 consecutive impacts at almost 20 m/s in the rotary tester. Furthermore, these results provided insights into pellet breakage mechanisms, evaluation of pneumatic pipe designs and construction of bench testing devices that purify the effect of surface vesus volume breakage. (C) 2020 Elsevier Ltd. All rights reserved.
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| 29. |
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| 30. |
- Lestander, Torbjörn
(författare)
-
Multivariate Process Control and Real Time Sensors in Practical Use
- 2012
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Konferensbidrag (refereegranskat)abstract
- Implementing multivariate process control and/or real time sensors gives opportunities to achieve several improvements like productivity, scrap rate, improve and optimize product quality etc. This becomes possible because the production organization gets a fast response on the process state and key quality parameters of raw materials and products. Hence they can very quickly take corrective actions when the process or the material in process is not in an optimal state. The fast response also improves the possibilities to optimize the process and product quality. This requires however in many cases a change of mindset in the production organization. The technical performance is of course very important, the system has to generate reliable output in terms of accurate description of the process and predictions and it has to be running stable. However, the gain in production efficiency and/or improvement of the product quality that is the main driver for implementing the system in the first place is not made directly by the system but through active use of it. This part has to be made by the production organization of the company. Examples from case studies and some statistical results and considerations are presented.
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| 31. |
- Lestander, Torbjörn, et al.
(författare)
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Near infrared image analysis for online identification and separation of wood chips with elevated levels of extractives
- 2012
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Ingår i: Journal of Near Infrared Spectroscopy. - : SAGE Publications. - 0967-0335 .- 1751-6552. ; 20, s. 591-599
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Tidskriftsartikel (refereegranskat)abstract
- Forest-based biorefinery feedstocks are usually broken up into wood chips prior to any form of processing. These wood chips have a complex and highly variable composition, although they may look identical to an inexperienced observer. Some chips have high contents of valuable extractives. Therefore, it would be desirable to separate such chips that are rich in extractives. Various fractions of pine and spruce wood were used to acquire near infrared 11000-2498 nm) hyperspectral images in order to explore the usefulness of multivariate image analysis for detection and separation purposes. Multivariate modelling by image principal component analysis detected large variations in extractive content among wood chips of different biomass types, for example, sapwood, heartwood and knotwood. The extractive parts could be classified in the images and their content could be reasonably well predicted. Partial least squares (PLS) regression models could be made between collected spectra and measured extractive contents. These worked better for milled and homogenised bulk samples than for average image spectra. Regression coefficients showed that the C-H bonds in the spectra were responsible for the validity of the models. The average image PLS models could be used to make prediction images showing the location of the regions with high extractive content in knotwood. The results indicate that extremely rapid spectral-based fractionation could be used to separate tailored biomass streams of wood chips.
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| 32. |
- Lestander, Torbjörn, et al.
(författare)
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NIR provides excellent predictions of properties of biocoal from torrefaction and pyrolysis of biomass
- 2014
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 16:12, s. 4906-4913
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Tidskriftsartikel (refereegranskat)abstract
- When biomass is exposed to high temperatures in torrefaction, pyrolysis or gasification treatments, the enrichment of carbon in the remaining 'green coal' is correlated with the temperature. Various other properties, currently measured using wet chemical methods, which affect the materials' quality as a fuel, also change. The presented study investigated the possibility of using NIR spectrometry to estimate diverse variables of biomass originating from two sources (above-ground parts of reed canary grass and Norway spruce wood) carbonised at temperatures ranging from 240 to 850 C-circle. The results show that the spectra can provide excellent predictions of its energy, carbon, oxygen, hydrogen, ash, volatile matter and fixed carbon contents. Hence NIR spectrometry combined with multivariate calibration modeling has potential utility as a standardized method for rapidly characterising thermo-treated biomass, thus reducing requirements for more costly, laborious wet chemical analyses and consumables.
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| 33. |
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| 34. |
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| 35. |
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| 36. |
- Lestander, Torbjörn
(författare)
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Pellet and briquette production
- 2013
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Ingår i: Technologies for converting biomass to useful energy: combustion, gasification, pyrolysis, torrefaction and fermentation. - 9780415620888 ; :4, s. 345-355
-
Bokkapitel (refereegranskat)
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| 37. |
- Lestander, Torbjörn, et al.
(författare)
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Prediction of Resin and Fatty Acid Content of Biorefinery Feedstock by On-line Near-Infrared (NIR) Spectroscopy
- 2010
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Ingår i: Energy and Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 24, s. 5148-5152
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Tidskriftsartikel (refereegranskat)abstract
- Extractives in biorefinery feedstock are a source of precursor chemicals and biofuel products. Resin and fatty acids (RFAs) in such extractives constitute an interesting fraction, which may contain both chemically attractive precursors and also problematic volatile organic compounds. On-line near-infrared (NIR) spectra were collected from a process stream, designed experimentally and involving softwood lignocelluloses; the data were regressed using partial least-squares to give RFA concentrations that varied between 0.1 and 0.5% (dry weight basis). At-line NI R models were also constructed using spectral data from pelletized samples from the process stream. In addition, off-line NIR modeling was conducted using softwoods with a wider R FA variation range (0.1-1.0% dry weight basis). All of the calibration models obtained exhibited good predictive abilities. The laboratory-based off-line NIR model explained 94.5% of the variation in concentrations and had a prediction error of 0.070% for the RFA content. The coefficient of variation (CV), representing the percentage of the ratio between the prediction error and the average concentration, was 17.8%. The on-line and at-line models explained 71.3-79.6% of the variation in the RFA concentrations and had prediction errors within the range of 0.026-0.041% and CVs of 13.7-18.1%. This was excellent in comparison to the ca. 10% error in accuracy when determining the RFA reference values. The results illustrate that on-line NI R spectroscopy provides a valid method for real-time predictions of RFA concentrations in biomaterials. This should facilitate better monitoring and process control as well as targeted pretreatments to obtain tailor-made biorefinery feedstock, thus adding value to the production process.
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| 38. |
- Lestander, Torbjörn
(författare)
-
Towards multivariate statistical process control in the wood pellet industry
- 2012
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 45, s. 152-158
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Tidskriftsartikel (refereegranskat)abstract
- The results illustrate the possibilities to implement MSPC in the wood pellet industry, potentially handling huge amounts of data. To develop and implement the next phase of process control more parameters must be included in the MSPC models, e.g. data acquired using on-line instruments to continuously collect information on variations in the stream of material. (c) 2012 Elsevier Ltd. All rights reserved.
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| 39. |
- Ma, Chunyan, et al.
(författare)
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Towards negative carbon emissions : Carbon capture in bio-syngas from gasification by aqueous pentaethylenehexamine
- 2020
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Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 279
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Tidskriftsartikel (refereegranskat)abstract
- In this work, an aqueous pentaethylenehexamine (PEHA) solution was studied for CO2 removal from bio-syngas for the first time. Firstly, pure CO2 absorption in aqueous PEHA solution under different conditions was conducted, and 20 wt% PEHA solution was identified as the best option. Secondly, the capture of CO2 was tested with synthetic syngas from a gas cylinder, and the species other than CO2 showed a negligible impact on CO2 removal. Finally, to evaluate the practical feasibility of using aqueous PEHA solution on the downstream CO2 capture, the pilot experiments of gasification with boreal forest-based biomasses were designed to provide real syngas with a realistic distribution in composition for further testing. The results showed that the operating conditions and the type of feedstocks affected the distribution in the bio-syngas composition. Among these feedstocks, at the optimal oxygen supply, using spruce needles generated the highest yields of CO and H2 and, meanwhile, gave rise to similar yields of other gases such as CO2, CH4, etc. The influence of the species other than CO2 for CO2 removal was negligible. Additionally, aqueous PEHA solution was tested as a biomass pretreatment agent, showing that no significant changes could be identified by the ultimate analysis (except for increased nitrogen content), but the yields of CO were affected negatively. On the other hand, when using the pretreated biomass by the aqueous PEHA solution, the NH3 concentration in bio-syngas reached to the highest (4000 parts per million), which slightly affected the CO2 absorption capacity and initial absorption rate of 20 wt% PEHA solution in a positive way.
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| 40. |
- Manavalan, Gopinathan, et al.
(författare)
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Electrochemically modified poly(dicyandiamide) electrodes for detecting hydrazine in neutral pH
- 2023
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 0888-5885 .- 1520-5045. ; 62:44, s. 18271-18279
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Tidskriftsartikel (refereegranskat)abstract
- A new technique for sensing nanomolar concentrations of hydrazine in water samples is reported. A screen-printed carbon electrode (SPCE) altered using an amine-azo functional group encompassing poly(dicyandiamide) is used in this study. The modified electrode exhibits an enhanced activity toward hydrazine detection at a lower overpotential and broad linear scale between 20 nM and 1 mM, with an accurate sensitivity value of 0.1 nA μm–1 cm–2. To the best of our knowledge, poly(dicyandiamide)-modified electrodes exhibit one of the lowest limits of detection for any metal-free electrode that detects 6.7 nM (S/N = 3) of hydrazine. The method established sufficient selectivity and better recoveries. Finally, the poly(dicyandiamide)-modified SPCE* is highly suitable for electrochemical determination of hydrazine in water samples from tap and lake.
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| 41. |
- Normark, Monica, et al.
(författare)
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Analysis, pretreatment and enzymatic saccharification of different fractions of Scots pine
- 2014
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Ingår i: BMC Biotechnology. - : BioMed Central (BMC). - 1472-6750. ; 14
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Tidskriftsartikel (refereegranskat)abstract
- Background: Forestry residues consisting of softwood are a major lignocellulosic resource for production of liquid biofuels. Scots pine, a commercially important forest tree, was fractionated into seven fractions of chips: juvenile heartwood, mature heartwood, juvenile sapwood, mature sapwood, bark, top parts, and knotwood. The different fractions were characterized analytically with regard to chemical composition and susceptibility to dilute-acid pretreatment and enzymatic saccharification. Results: All fractions were characterized by a high glucan content (38-43%) and a high content of other carbohydrates (11-14% mannan, 2-4% galactan) that generate easily convertible hexose sugars, and by a low content of inorganic material (0.2-0.9% ash). The lignin content was relatively uniform (27-32%) and the syringyl-guaiacyl ratio of the different fractions were within the range 0.021-0.025. The knotwood had a high content of extractives (9%) compared to the other fractions. The effects of pretreatment and enzymatic saccharification were relatively similar, but without pretreatment the bark fraction was considerably more susceptible to enzymatic saccharification. Conclusions: Since sawn timber is a main product from softwood species such as Scots pine, it is an important issue whether different parts of the tree are equally suitable for bioconversion processes. The investigation shows that bioconversion of Scots pine is facilitated by that most of the different fractions exhibit relatively similar properties with regard to chemical composition and susceptibility to techniques used for bioconversion of woody biomass.
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| 42. |
- Normark, Monica, 1980-
(författare)
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Pretreatment and enzymatic saccharification of lignocellulose : formation and effects of pseudolignin
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Production of advanced biofuels, green chemicals, and bio-based materials from renewable lignocellulosic biomass would contribute to decreased dependence on fossil resources and to sustainable development. The overall aim of the investigations was to explore how preprocessing and pretreatment technologies affected the chemical composition of cellulosic materials and their susceptibility to enzymatic saccharification, which is one of the major routes for biorefining of lignocellulose. Special attention was given to formation and effects of pseudolignin, an aromatic substance derived from polysaccharides. Pseudolignin is formed during dry thermal preprocessing, such as torrefaction, and during dilute-acid pretreatment, techniques that are highly relevant for biorefining of wood.The susceptibility of seven fractions of Scots pine to dilute-acid pretreatment and enzymatic saccharification was investigated. Harsh pretreatment conditions led to slow initial conversion, which was tentatively attributed to pseudolignin. Pretreatment with ionic liquids was investigated using substrates consisting of crystalline and amorphous cellulose, hemicelluloses, and wood. The susceptibility of torrefied spruce wood to enzymatic saccharification after pretreatment with acid or ionic liquid was investigated. The results showed that the negative effects of mild torrefaction on enzymatic saccharification were possible to overcome using pretreatment with the ionic liquid. In a subsequent study, the possibility to dissolve pseudolignin with ionic liquids and conventional solvents was explored. The effects of pseudolignin on wood polysaccharides and enzymatic saccharification were further studied using NMR, FTIR, XPS, TOF-SIMS, and SEM. The surface-sensitive analytical methods TOF-SIMS, XPS, and SEM revealed how pseudolignin formed a coat on the surface of the polysaccharide, which could explain the effects on the enzymatic saccharification.
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| 43. |
- Rudolfsson, Magnus, et al.
(författare)
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Combined effects of torrefaction and pelletization parameters on the quality of pellets produced from torrefied biomass
- 2017
-
Ingår i: Applied Energy. - : Elsevier. - 0306-2619 .- 1872-9118. ; 191, s. 414-424
-
Tidskriftsartikel (refereegranskat)abstract
- A combined torrefaction and pelletization study was performed at industrially relevant settings using a factorial design. First, wood chips of Scots pine were torrefied at high temperatures (291-315 degrees C) and short residence times (6-12 min), facilitating high throughput in a continuous pilot-scale torrefaction process. Then the torrefied materials were pelletized, also in pilot-scale, using varying moisture contents (MCs) (10-14%), sieve sizes (4-6 mm), and press channel lengths (PCLs) (25 and 30 mm), in all 19 batches, each of 400 kg. The resulting so called black pellets exhibited bulk densities of 558-725 kg m(-3), durabilities of 46.3-86.5%, and fines contents of 3.8-85.8%. Through multiple linear regression modelling of all 11 responses, it was found that the parameter with the greatest influence on the responses was the torrefaction temperature, followed by torrefaction time, MC, and PCL. Longer PCL and higher MC resulted in higher pellet quality, with less fines and greater bulk density and durability. Furthermore, a low torrefaction degree decreased the amount of power required for pelletization. The energy required to grind pellets into a powder (<0.5 mm) decreased with increasing torrefaction degree as expected, but also with decreasing MC before pelletizing. Pyrolysis-GC/MS analysis of thermal degradation products from the pellets revealed correlations with the torrefaction temperature and time, but no correlations with the pelletization process. These results are useful for mapping chemical changes in torrefied materials and identifying complementary torrefaction and pelletization settings. Specifically of interest is adjustment of PCLs at low intervals to better match friction properties of torrefied materials.
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| 44. |
- Rudolfsson, Magnus, et al.
(författare)
-
Energy savings through late-steam injection - A new technique for improving wood pellet production
- 2020
-
Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526 .- 1879-1786. ; 254
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Tidskriftsartikel (refereegranskat)abstract
- Wood pellet production has developed into an important global industry. Improving pre-processing operations is vital in keeping the industry competitive as energy and material inputs are reflected in the cost and sustainability of wood pellets as a product. In this study, a new method of steam conditioning in pelleting was evaluated based on semi-industrial experiments and thermodynamics principles. Late-steam injection was compared to conventional steam conditioning in an industrial production scenario of 100,000 tonnes per year using a rotating ring-die pellet mill, the most common mill type used in the industry. The differences in energy use and production cost were determined and the environmental footprint of produced pellets was assessed using the renewable energy directive (RED) framework for biofuels. The results showed that late-steam injection dramatically reduced steam consumption and feedstock drying needs in pelleting and, to a lesser extent, the mill-specific energy use. The economic benefit, based on the industrial production scenario, equated to an annual operational savings of 0.25 MV (3.9 %) which, over a ten-year plant lifetime, had a present value of 1.3 MV. The CO2-equivalent emissions of produced pellets, for co-firing applications, was significantly improved. These findings were specific to rotating ring-die pellet mills so that the potential for retrofitting late-steam injection solutions in existing industrial sites is large. The technology is seen as a means of increasing the competitiveness of global wood pellet production. (C) 2020 Elsevier Ltd. All rights reserved.
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| 45. |
- Rudolfsson, Magnus, et al.
(författare)
-
New tool for improved control of sub-process interactions in rotating ring die pelletizing of torrefied biomass
- 2017
-
Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 190, s. 835-840
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Tidskriftsartikel (refereegranskat)abstract
- A new concept was developed for feed layer formation control and to obtain continuous pellet production when pelletizing torrefied biomass. The materials pelletized were softwood forest residues and a hardwood species which both had been torrefied at 308 degrees C for 9 min. The torrefied wood chips were milled over a screen size of 6 mm and the torrefied feedstock moisture content was adjusted to about 9% before pelletizing. Two types of pelletizers were used; one with a stationary ring die and one with a rotating ring die. With a traditional, non-cooled die configuration, the die temperature increased to 75-78 degrees C. During temperature increment, pellet production deteriorated and finally ceased at approximately 80 degrees C. This phenomenon was caused by a breakdown of the feed-layer formation between the free rolling rollers and the die. However, continuous production could be sustained when the die was cooled. A new tool was developed based on nozzle injection of water directly onto the feed layer. By this course of action pellet production was sustained at temperatures well above 80 degrees C. This proof-of-concept for a new tool to control sub-process interactions in ring die pelletizing also includes use of loW initial moisture content to utilize the flowability of torrefied particulates and, thus, avoid problems connected to feeding, conveying and silo discharging which frequently occurs at higher feedstock moisture contents. (C) 2016 Published by Elsevier Ltd.
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| 46. |
- Rudolfsson, Magnus, et al.
(författare)
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Process optimization of combined biomass torrefaction and pelletization for fuel pellet production - A parametric study
- 2015
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 140, s. 378-384
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Tidskriftsartikel (refereegranskat)abstract
- Torrefaction of plant biomass has the capacity to produce a fuel with increased energy density and homogeneity, but there are reports that it changes the pelletizing properties of the biomass, making it more difficult to obtain high quality pellets. A parametric study was therefore conducted in which three key qualitative parameters, degree of torrefaction (250-300 °C), moisture content (0-10%) and pelletizing temperature (125-180 °C), were varied according to a five level fractional factorial design, also including particle size as a qualitative parameter. Pelletizing at 300 MPa (pellet densities: 1.0-1.2 mg/mm3) was undertaken using a single pellet press and the responses recorded were compression work (Wcomp), maximal force to overcome static friction (Fmax), kinetic friction work (Wfric), single pellet dimensions and strength. Small particles reduced Wcomp and Fmax, but increased strength. As expected, all other parameters also had significant effects. In general, less energy was required for Wcomp, Wfric and Fmax at lower degrees of torrefaction and higher moisture contents and when pelletizing was conducted at higher temperatures. The process window to optimize pellet strength was narrow and, surprisingly, somewhat higher moisture content at higher degrees of torrefaction increased strength. This narrow production window in combination with feedstock variations may, in practical pelletizing situations, result in varying quality. Furthermore, the study illustrates that factorial experiments using single-pellet devices provide new insights that are of importance for the next generation of pelletizing of torrefied biomass.
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| 47. |
- Rönnbäck, Marie, et al.
(författare)
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Utveckling av framtida konkurrenskraftig närvärme (0,05-20 MWth) med säkrad bränslekvalitet samt hög tillgänglighet, effektivitet och miljöprestanda
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The heating sector (0.05 to 20 MW) is during the coming years facing an increased competition for (bio) fuels and, at the same time, an expanded broadening of the raw material base for fuels. At the same time the demand for availability, efficiency and environmental performance are increasing. This report describes key barriers, knowledge gaps and needs for research, development and demonstration activities identified. Producers of fuels and of combustion equipments as well as users have been identified and their views have been collected through interviews and / or questionnaires. Research and ongoing programs and activities in Sweden are described briefly. The results show great need for knowledge of new fuels in the whole chain from fuel processing to quality assurance, combustion and emission reduction. There is also great need for coordination of resources, clarification of the research structure, increased contact and improved communication and implementation of results. Based on the results a structure, content and funding of a coordinated R & D program with a focus on the heating sector 0,05-20 MW is proposed. Key factors for success are the inclusion of the entire chain fuel-conversion-system/environment, coordination of physical locations for research and development, and overall governance. All three parts basic research, applied research and demonstration should be included.
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| 48. |
- Samuelsson, Robert, et al.
(författare)
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Effect of biomaterial characteristics on pelletizing properties and biofuel pellet quality
- 2009
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Ingår i: Fuel processing technology. - : Elsevier. - 0378-3820 .- 1873-7188. ; 90:9, s. 1129-1134
-
Tidskriftsartikel (refereegranskat)abstract
- Sawdust of conifers as a by-product from saw mills is the most commonly used biomaterial for pellet production in Sweden today. Experiences from the biofuel pellet industry indicate that different biomaterial properties influence the final pellet quality. A systematic study was conducted where five factors were varied according to a two level fractional factorial design. The factors were: tree species (Scots pine, Norway spruce); origin of growth-place (latitudes 57 and 64°N); storage time of sawdust (0 and 140 days), moisture content (9 and 12%) and steam treatment (2 and 6 kg/h). The measured responses bulk density and mechanical durability represented the pellet quality while the press current and the fines produced in the pelletizing process were measures of the pelletizing property.The results showed that low moisture content and long storage time resulted in increased bulk densities and press currents. For mechanical durability and fines, a long storage time and intermediate moisture contents were found favourable. In addition, indications were found that the reduction of fatty and resin acids during the storage also influenced the pelletizing properties and the pellet quality.
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| 49. |
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| 50. |
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