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  • 1.
    Abdelaziz, Omar
    et al.
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Capanema, Ewellyn
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Ajao, Olumoye
    Canmet ENERGY, Canada.
    Kristensen, Tove
    Lund University, Sweden.
    Hosseinaei, Omid
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Benali, Marzouk
    Canmet ENERGY, Canada.
    Hulteberg, Christian
    Lund University, Sweden.
    A Rapid and Tunable Approach for the Fractionation of Technical Kraft Lignin2023Inngår i: Chemical Engineering Transactions, ISSN 1974-9791, E-ISSN 2283-9216, Vol. 99, s. 67-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Reducing the heterogeneity of technical lignin is essential to obtain predictable and high-performance polymeric materials that are suitable for high-value applications. Organic solvents with different polarities and solubilities can be used to fractionate lignin and reduce the complexity and diversity of its chemical structure. Among the various solvents and solvent mixtures, acetone-water mixtures offer an energy-efficient, cost-effective, and environmentally friendly means of lignin fractionation. In the present study, temperature-induced acetone-water fractionation was investigated to refine the properties of a technical softwood Kraft lignin, i.e., LignoBoost™ lignin. Relatively mild operating conditions were tested, namely, temperatures of 70-110°C and autogenous pressure. A factorial experimental design was developed using the Design-Expert® software, and three factors (temperature, time, and acetone concentration) were investigated. It was found that temperature-induced fractionation could increase lignin homogeneity and maintain high lignin solubilization with a short processing time (<1 h). It was also possible to tune the properties of the soluble lignin fraction (yield and weight-average molecular weight) based on the factorial models developed. The techno-economic evaluation confirmed the commercial viability of this fractionation process. 

  • 2.
    Achtel, Christian
    et al.
    Friedrich Schiller University of Jena, Germany.
    Jedvert, Kerstin
    RISE - Research Institutes of Sweden (2017-2019), Material och produktion, IVF. Friedrich Schiller University of Jena, Germany.
    Kosan, Birgit
    TITK Thuringian Institute of Textile and Plastics Research, Germany.
    Seoud, Omar. A.El
    University of São Paulo, Brazil.
    Heinze, Thomas
    Friedrich Schiller University of Jena, Germany.
    Dissolution capacity of novel cellulose solvents based on triethyloctylammonium chloride2017Inngår i: Macromolecular Chemistry and Physics, ISSN 1022-1352, E-ISSN 1521-3935, Vol. 218, nr 21, artikkel-id 1700208Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dissolution of cellulose from various sources (microcrystalline cellulose and different dissolving grade pulp fibers) is investigated in solvent systems based on triethyl(n-octyl)ammonium chloride (N2228Cl). Clear cellulose solutions are obtained with N2228Cl in a variety of solvents, e.g., dimethyl sulfoxide, N,N-dimethylacetamide, and acetone. It is possible to prepare clear cellulose solutions from pulp fibers with concentrations up to 15 wt%. However, it is found that the cellulose is degraded, especially when neat (i.e., molten) N2228Cl is used as a solvent. The present work includes comprehensive rheological characterization of the cellulose solutions, both with shear and extensional rheology. In most cases, the viscosity values are low (complex viscosities below 100 Pa s for 5–10 wt% dissolved cellulose), and the solutions show more Newtonian than viscoelastic behavior. 

    Fulltekst (pdf)
    fulltext
  • 3. Agnihotri, S.
    et al.
    Johnsen, I.A.
    RISE., Innventia, PFI – Paper and Fiber Research Institute.
    Moe, S.
    Gregersen, Ø.
    More selective biorefining of softwood by combined hot water and ethanol organosolv pretreatment2011Konferansepaper (Fagfellevurdert)
  • 4. Ahlberg, C.
    et al.
    Lundell, F.
    Söderberg, L. Daniel
    RISE., Innventia.
    Self-organization of fibers in a suspension between two counter-rotating discs2009Inngår i: Proceedings of the ASME Fluids Engineering Division Summer Conference 2009, 2009, Vol. 1, nr PART A, s. 585-592Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The behavior of fibers suspended in a flow between two flat counter-rotating discs has been studied experimentally. Captured images of the fibers in the flow were analyzed by steerable filters, to extract positions and orientations of the fibers. Experiments were performed for gaps between the discs of less than one fiber length, and for equal absolute values of the angular velocities for the discs. The length-to-diameter ratio of the fibers was approximately 14. During certain conditions, the fibers organized themselves in a distinct manner, which we will denote as fiber trains, in which three or more fibers are aligned next to each other, at the same radial position, with a short fiber-to-fiber distance. The direction of the individual fibers is radial and the direction of the whole train is tangential. Trains containing more than 60 fibers have been observed and are quite impressing.

  • 5.
    Ahlroth, Mikael
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Bialik, Marta
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi. RISE., Innventia.
    Jansson, Mikael
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi. Andritz, Sweden.
    Rosenqvist, Kristian
    ÅF, Sweden.
    Bark and wood powder firing in the recovery boiler for maximum power generation2017Inngår i: International chemical recovery conference, May 24-26, 2017, Halifax, Canada, PAPTAC , 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The effect of co-firing bark or wood powder in a recovery boiler is studied. The effect of increased NPEs in the liquor and lime cycles, the FMT and sticky dust and the smelt composition is assessed by using simulation tools. The results indicate that generating an additional 22-39% HP steam for power production by firing wood powder in the recovery boiler is a viable option, if Cl and K are purged from the ESP dust by a treatment unit. The smelt is enriched with the same proportion of NPEs as the as-fired liquor.

  • 6.
    Ahlroth, Mikael
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Bialik, Marta
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Jensen, Anna
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi.
    Hydrothermal carbonisation of effluent sludge2017Inngår i: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017: NWBC 2017, Stockholm: RISE Bioekonomi , 2017, s. 156-158Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Research was carried out to investigate hydrothermal carbonisation (HTC) treatment of different effluent sludges from the pulp and paper industry in a Parr-reactor. Sludge samples were evaluated from a thermomechanical paper (TMP) mill and a kraft market pulp mill (NSWBK). The issues studied included HTC treatment time; addition of acid and alkali; dewatering properties of the resulting slurry; and non-process element (NPE) concentration in the original sludge, the filtrate and the filter cake. It was found that HTC improved the fuel quality. Alkali metals were depleted in TMP and NSWBK sludge and in both cases, the sludge was easier to dewater. The yield was better for TMP than NSWBK sludge and the yield losses had a negative impact on the NSWBK sludge. TMP sludge was already a viable boiler fuel and the treatment improved the fuel qualities even more. The HTC treatment of the NSWBK sludge resulted in lower chlorine and potassium, with lower fuel-nitrogen resulting in lower nitrous oxide. Although HTC treatment improved the low heating value of the sludge, this was counteracted by yield loss. Compared with untreated NSWBK, the overall energy impact was negative. HTC treatment offered mixed opportunities from the viewpoint of the recovery cycle.

    Fulltekst (pdf)
    fulltext
  • 7. Albertsson, A.-C.
    et al.
    Voepel, J.
    Edlund, U.
    Dahlman, Olof
    RISE., Innventia.
    Söderqvist-Lindblad, M.
    Design of renewable hydrogel release systems from fiberboard mill wastewater2010Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 11, nr 5, s. 1406-1411Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new route for the design of renewable hydrogels is presented. The soluble waste from masonite production was isolated, fractionized, and upgraded. The resulting hemicellulose rich fraction was alkenyl-functionalized and used in the preparation of covalently cross-linked hydrogels capable of sustained release of incorporated agents. Said hydrogels showed a Fickian diffusion-based release of incorporated bovine serum albumin. Also, a method for the coating of seeds with hydrogel was developed. The sustained release of incorporated growth retardant agents from the hydrogel coating on rape seeds was shown to enable the temporary inhibition of germination.

  • 8.
    Aldaeus, Fredrik
    RISE - Research Institutes of Sweden, Bioekonomi, Biobaserade material.
    The Bioeconomy Research Programme 2018-20202018Inngår i: The 8th Nordic Wood Biorefinery Conference: NWBC 2018: proceedings / [ed] Hytönen Eemeli, Vepsäläinen Jessica, Espoo: VTT Technical Research Centre of Finland , 2018, s. 83-Konferansepaper (Annet vitenskapelig)
  • 9.
    Aldaeus, Fredrik
    et al.
    RISE., Innventia.
    Dedic, Dina
    RISE., Innventia.
    Karpenja, Tatjana
    RISE., Innventia.
    Magnusson, Mikael
    RISE., Innventia.
    Modorato-Rosta, Caroline
    RISE., Innventia.
    Rosén, Fredrik
    RISE., Innventia.
    Sundin, Konstantin
    RISE., Innventia.
    Lindström, Mikael
    RISE., Innventia.
    Lucisano, Marco
    RISE., Innventia.
    Towards a cellulose-based society: current trends, future scenarios, and the role of the wood biorefinery2016Inngår i: Proceedings of the 14th European workshop on lignocellulosics and pulp, 2016, Vol. 2, s. 125-127Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    There is a great need to maintain research for a future in which the traditional value chains of the forest industry are combined with the needs and demands of a bio-based economy. In such a future, the pulp mill biorefinery will be a crucial node. In order to map the transformation from a fossil-based society to a cellulose-based society, a global consumer survey has been made. In addition, interviews and workshops with various players throughout the bio-economy field have been accomplished. Several current trends that affect the road to a cellulose-based society have been identified. These trends are describing the effects of urbanization, consumer behaviour, new business models, material recycling, open innovation, and the need for early demonstration of new research. The trends have been combined with uncertainties into a number of plausible scenarios describing the society and the role of cellulose in the year 2030.

  • 10.
    Aldaeus, Fredrik
    et al.
    RISE., Innventia.
    Larsson, Karolina
    RISE., Innventia.
    Stevanic Srndovic, Jasna
    RISE., Innventia.
    Kubat, Mikaela
    RISE., Innventia. RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Karlström, Katarina
    RISE., Innventia.
    Norberg, Lars
    RISE., Innventia.
    Anadolyan, Shant
    RISE., Innventia.
    Peciulyte, Ausra
    Chalmers University of Technology, Sweden.
    Olsson, Lisbeth
    Chalmers University of Technology, Sweden.
    Larsson, Per Tomas
    RISE., Innventia.
    The supramolecular structure of cellulose-rich wood and wheat straw pulps can be a determinative factor for enzymatic hydrolysability2016Inngår i: The 7th Workshop on cellulose, regenerated cellulose and cellulose derivatives, 2016, s. 39-39, artikkel-id 11Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Conversion of biomass to biofuels and other products is a research area that is currently attracting a great amount of interest, particularly because such production may be envisaged as a key part of any bio-based economy. Lignocellulosic biomass is abundant and sustainable, and can therefore potentially support large-scale production of biofuel as an alternative to petroleum-based fuel.

    The enzymatic hydrolysability of three industrial pulps, five lab made pulps, and one microcrystalline cellulose powder was assessed using commercial cellulolytic enzymes. To gain insight into the factors that influence the hydrolysability, a thorough characterization of the samples was done, including their chemical properties (cellulose content, hemicellulose content, lignin content, and kappa number), their macromolecular properties (peak molar mass, number-average molar mass, weight-average molar mass, polydispersity, and limiting viscosity) and their supramolecular properties (fibre saturation point, specific surface area, average pore size, and crystallinity). The hydrolysability was assessed by determination of initial conversion rate and final conversion yield, with conversion yield defined as the amount of glucose in solution per unit of glucose in the substrate. Multivariate data analysis revealed that for the investigated samples the conversion of cellulose to glucose was mainly dependent on the supramolecular properties, such as specific surface area and average pore size. The molar mass distribution, the crystallinity, and the lignin content of the pulps had no significant effect on the hydrolysability of the investigated samples.

    In addition, experiments were carried out aiming at identifying suitable conditions for pre-treatment of wheat straw, for the purpose of making cellulose rich pulps with improved enzymatic reactivity. Two sets of conditions for pre-treatment of wheat straw were identified; a combination of low temperature alkaline washing and acid pre-hydrolysis, or high temperature acid pre-hydrolysis. Both bleached wheat straw pulps showed similar enzymatic reactivity. However, the enzymatic reactivity of both bleached wheat straw pulps was found to be significantly less than what has been achieved for wood pulps. A probable explanation for the low enzymatic reactivity of the bleached wheat straw pulp can be the small pore size, limiting the access for enzymes to the cellulose surfaces in the fibre wall interior.Text, figures and tables in an extended abstract (< 4 pages with title and references).

  • 11.
    Aldaeus, Fredrik
    et al.
    RISE., Innventia.
    Larsson, Karolina
    RISE., Innventia.
    Stevanic Srndovic, Jasna
    RISE., Innventia.
    Kubat, Mikaela
    RISE., Innventia. RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Karlström, Katarina
    RISE., Innventia.
    Peciulyte, Ausra
    Chalmers University of Technology, Sweden.
    Olsson, Lilsbeth
    Chalmers University of Technology, Sweden.
    Larsson, Per Tomas
    RISE., Innventia.
    The supramolecular structure of cellulose-rich wood pulps can be a determinative factor for enzymatic hydrolysability2015Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 22, nr 6, s. 3991-4002Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The enzymatic hydrolysability of three industrial pulps, five lab made pulps, and one microcrystalline cellulose powder was assessed using commercial cellulolytic enzymes. To gain insight into the factors that influence the hydrolysability, a thorough characterization of the samples was done, including their chemical properties (cellulose content, hemicellulose content, lignin content, and kappa number), their macromolecular properties (peak molar mass, number-average molar mass, weight-average molar mass, polydispersity, and limiting viscosity) and their supramolecular properties (fibre saturation point, specific surface area, average pore size, and crystallinity). The hydrolysability was assessed by determination of initial conversion rate and final conversion yield, with conversion yield defined as the amount of glucose in solution per unit of glucose in the substrate. Multivariate data analysis revealed that for the investigated samples the conversion of cellulose to glucose was mainly dependent on the supramolecular properties, such as specific surface area and average pore size. The molar mass distribution, the crystallinity, and the lignin content of the pulps had no significant effect on the hydrolysability of the investigated samples.

  • 12.
    Aldaeus, Fredrik
    et al.
    RISE., Innventia.
    Larsson, Karolina
    RISE., Innventia.
    Stevanic Srndovic, Jasna
    RISE., Innventia.
    Kubat, Mikaela
    RISE., Innventia. RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Karlström, Katarina
    RISE., Innventia.
    Peciulyte, Ausra
    Olsson, Lisbeth
    The influence of various pulp properties on the enzymatic hydrolyzability2014Konferansepaper (Fagfellevurdert)
  • 13.
    Aldaeus, Fredrik
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi. RISE., Innventia.
    Olsson, Anne-Mari
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi. RISE., Innventia.
    Stevanic Srndovic, Jasna
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi. RISE., Innventia.
    Miniaturized determination of ash content in kraft lignin samples using oxidative thermogravimetric analysis2017Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, nr 2, s. 280-282Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A study has been made of several aspects of determination of ash content in kraft lignin samples using thermogravimetric analysis (TGA). Three different methods were used; with the main differences between the methods being that two have a temperature hold at 250 deg C to remove volatiles and that the three methods use different maximum temperatures, namely 525, 550 and 575 deg C, respectively. The three kraft lignins used were produced using the LignoBoost lignin isolation process. It has been demonstrated that the results obtained by the different temperature programmes showed no significant difference. The results were comparable with those from using oven ignition. Moreover, the limit of quantification was several orders of magnitude lower than when using oven ignition. It has been recommended that if TGA is used for determination of ash content, a temperature programme from a standard method should be used, which should be mentioned together with the results. The temperature programme in method one (corresponding to ISO 1762) was the shortest and the preferable method. A well as requiring less labour due to fewer movements in the analytical protocol, the TGA methods enabled a high sample throughput due to autosampling possibilities.

  • 14.
    Aldaeus, Fredrik
    et al.
    RISE., Innventia.
    Olsson, Anne-Mari
    RISE., Innventia.
    Stevanic Srndovic, Jasna
    RISE., Innventia.
    Miniaturized determination of ash content in kraft lignin samples using thermogravimetric analysis2015Inngår i: 18th International Symposium on Wood, Fiber and Pulping Chemistry, September 9-11, 2015, Vienna, 2015, s. 352-354Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Thermogravimetric analysis (TGA) in oxidative conditions is a promising alternative to ignition in oven for the determination of inorganic residue, commonly referred to as ash. It is here shown that TGA can be used with temperature programs resembling those in standardized methods for oven ignition, and obtainequivalent results even though the sample amount is several orders of magnitude lower. The precision and limit of quantification of TGA is also discussed.

  • 15.
    Aldaeus, Fredrik
    et al.
    RISE., Innventia.
    Schweinebarth, Hannah
    RISE., Innventia.
    Jacobs, Anna
    RISE., Innventia.
    Simplified determination of Klason lignin in black liquor and lignin samples2010Inngår i: 11th European workshop on lignocellulosics and pulp: EWLP 2010, 2010, s. 45-48Konferansepaper (Annet vitenskapelig)
  • 16.
    Alfthan, Johan
    RISE., Innventia.
    Experimental study of non-linear stress relaxation and creep of paper materials and the relation between the two types of experiments2010Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 25, nr 3, s. 351-357Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The non-linear time-dependent mechanical behaviour of three different commercial paper grades was investigated. Stress relaxation and creep tests were carried out in MD and CD using different load levels. The strain in each test was split in a linear part and a non-linear part. From the stress and the linear part of the strain in the test, a stress relaxation modulus or a creep compliance was calculated. The stress relaxation moduli and creep compliances determined in this way were observed to be independent of the load level. The stress relaxation moduli and creep compliances for each paper were further independent of the loading direction (MD/CD) when scaled by the elastic modulus. It was also shown that the stress relaxation modulus was approximately equal to the inverse of the creep compliance, which is what would have been expected if linear viscoelastic theory had been applicable.

  • 17.
    Alfthan, Johan
    et al.
    RISE., Innventia.
    Björklund, Magnus
    Measuring creep with confidence2014Konferansepaper (Fagfellevurdert)
  • 18.
    Alm, H.K.
    et al.
    RISE., Innventia.
    Ström, Göran
    RISE., Innventia.
    Karlström, Katarina
    Schoelkopf, J.
    Gane, P.A.C.
    Effect of excess dispersant on surface properties and liquid interactions on calcium carbonate containing coatings2010Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 25, nr 1, s. 82-92Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this work was to identify what effects excess amount of sodium polyacrylate, a commonly used dispersant, has on the coating properties and the interaction between ink and the paper coating in offset printing. Since polyacrylate strongly interacts with calcium ions, soluble calcium salt was added to some coating colours to illustrate the impact of charge neutralization by calcium ions. It was found that the coating structure was only slightly affected by the extra addition of polyacrylate, showing some weak flocculation, whereas the surface chemistry was strongly influenced. The coatings became more polar and interacted more strongly with water. This resulted in slower ink setting and reduced ink-paper coating adhesion, especially in the presence of applied water/dampening solution, which are identified as contributory factors in ink piling and print mottle.

  • 19.
    Almgren, K.M.
    et al.
    RISE., Innventia.
    Gamstedt, E.K.
    RISE., Innventia.
    Characterization of interfacial stress transfer ability by dynamic mechanical analysis of cellulose fiber based composite materials2010Inngår i: Composite interfaces (Print), ISSN 0927-6440, E-ISSN 1568-5543, Vol. 17, nr 9, s. 845-861Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The stress transfer ability at the fiber-matrix interface of wood fiber composites is known to affect the mechanical properties of the composite. The evaluation of interface properties at the level of individual fibers is however difficult due to the small dimensions and variability of the fibers. The dynamical mechanical properties of composite and constituents, in this case wood fibers and polylactide matrix, was here used together with micromechanical modeling to quantify the stress transfer efficiency at the fiber-matrix interface. To illustrate the methodology, a parameter quantifying the degree of imperfection at the interface was identified by inverse modeling using a micromechanical viscoelastic general self-consistent model with an imperfect interface together with laminate analogy on the composite level. The effect of moisture was assessed by comparison with experimental data from dynamic mechanical analysis in dry and moist state. For the wood fiber reinforced polylactide, the model shows that moisture absorption led to softening and mechanical dissipation in the hydrophilic wood fibers and biothermoplastic matrix, rather than loss of interfacial stress transfer ability.

  • 20.
    Ambjörnsson, Helene Almlöf
    et al.
    Karlstad University, Sweden.
    Östberg, Linda
    Karlstad University, Sweden.
    Schenzel, Karla C.
    Martin Luther University Halle-Wittenberg, Germany.
    Larsson, Per Tomas
    RISE., Innventia.
    Germgård, Ulf
    Karlstad University, Sweden.
    Enzyme pretreatment of dissolving pulp as a way to improve the following dissolution in NaOH/ZnO2014Inngår i: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 68, nr 4, s. 385-391Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The dissolution of a softwood dissolving pulp in a NaOH/ZnO system was improved by means of a three-stage pretreatment with an initial xylanase treatment, followed by an alkaline extraction, and finally an endoglucanase stage. The solubility of the pulp increased from 29% to 81%, although the crystallinity and the specific surface area of the pulp did not change during the enzymatic treatment.

  • 21.
    Andersson, Christian
    et al.
    RISE., Innventia.
    Fellers, Christer
    RISE., Innventia.
    Evaluation of the stress-strain properties in the thickness direction: Particularly for thin and strong papers2012Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, nr 2, s. 287-294Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The performance of the paper in a number of converting operations such as creasing, bending, printing, and plastic coating put great demands on the mechanical properties in the thickness direction of the material. The knowledge of strength, elastic- and plastic behavior in tension and compression in the thickness direction is needed for a comprehensive description of the performance of the material in these operations. In spite of its importance, very few publications deal with the evaluation of the entire tensile stress-strain curve of paper in the thickness direction. A likely reason for this is the intrinsic difficulty of testing a thin, uneven, porous, fibrous and compressible material such as paper with sufficient precision and testing time efficiency. The z-directional strength test is usually performed by fastening the paper by means of double-adhesive tape to metal platens. The platens are fastened in a testing machine and strained to break. The adhesion of the tape is the limiting factors for how strong papers that can be tested. The tape-based method also is expected to have a lower limit in grammage due to the penetration of the adhesive. The aim of the present publication was to show a procedure how to evaluate the entire stress-elongation curve in the z-direction of papers, using a lamination method for fastening the paper to the metal platens. From this curve the z-strength, z-modulus, z-strain at break, zenergy at break and z-fracture energy could be extracted. Such information is, so far, non-existing in the literature.

  • 22.
    Andersson, Sofia
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Biobaserade material.
    Bengtsson, Andreas
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Bioraffinaderi och energi. KTH Royal institute of technology, Sweden.
    Åkerström, Mårten
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Bioraffinaderi och energi.
    Sedin, Maria
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Papperstillverkning och förpackningar.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden (2017-2019), Bioekonomi, Biobaserade material.
    The impact of inorganic elements on lignin‐based carbon fibre quality2018Inngår i: 15th European workshop on lignocelllulosics and pulp: Proceedings for poster presentations, 2018, s. 119-122Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The influence of inorganic elements on lignin ‐based carbon fibre (CF) quality was studied using sulphates of Na +, K+, Mg2+, Fe2+, Al3+. The metal sulphates were added to wet spun prefibres made from softwood kraft lignin (SKL):cellulose (70:30) and melt spun prefibres made from low molecular mass SKL. An increase in concentration from 0.1 w% to about 0.4 w% did neither affect the mechanical properties nor the morphology as observed by SEM. In contrast, metal sulphates added to the initial 0.45 w% to a total range 1.5 to 5.0 w%, was found detrimental to the melt spinning and to the final CF quality. Thus, the recommendation of <0.1 w% ash in kraft lignin may be exceeded, but more research is needed to establish the upper concentration limit.

  • 23.
    Anheden, Marie
    et al.
    RISE., Innventia.
    Ehn, Christian
    RISE., Innventia.
    The role of intermediate products in biorefinery development: Kraft lignin and pyrolysis oil as intermediates for production of naphtha cracker feed from forest-based raw materials2015Inngår i: NWBC 2015. Proceedings of the 6th Nordic Wood Biorefinery Conference held in Helsinki, Finland, 20-22 Oct. 2015, 2015, s. 210-219Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Research has been undertaken to estimate key performance factors important for development of biomass value chains with intermediate products. In the case selected, the end-product had to be suitable as feed product to a naphtha cracker. Pyrolysis oil and kraft lignin were the investigated intermediates, while yield, cost and carbon dioxide footprint were compared with direct production of bio naphtha from forest residues at the petrochemical plant and fossil naphtha. Three bio-based value chains were evaluated: without intermediate; with pyrolysis oil as intermediate; and with kraft lignin separated from black liquor as intermediate. Innventia AB's simulation model in WinGEMS was used to simulate the hypothetical reference pulp mill and the effects of integration with the lignin removal (LignoBoost) and pyrolysis equipment. It has been concluded that the use of intermediates produced integrated with decentralised local industrial plants could reduce total cost and carbon dioxide emissions of transporting forest based biomass to a centrally located conversion plant. However, the economic benefit was not very large compared with the overall value chain cost to produce the final product. Kraft lignin from pulp production was a very interesting intermediate, particularly in the case of the economic benefit

  • 24.
    Anheden, Marie
    et al.
    RISE - Research Institutes of Sweden, Bioekonomi, Bioraffinaderi och energi.
    Kulander, Ida
    RISE - Research Institutes of Sweden, Bioekonomi, Bioraffinaderi och energi.
    Pettersson, Karin
    Wallinder, Johan
    RISE - Research Institutes of Sweden, Bioekonomi, Bioraffinaderi och energi.
    Vamling, Lennart
    Chalmers University of Technology, Sweden.
    Hjerpe, Carl Johan
    F Industri, Sweden.
    Fugelsang, Malin
    F Industri, Sweden.
    Håkansson, Åsa
    Preem, Sweden.
    Evaluation of alternative routes for production of bio-oil from forest residues and kraft lignin2018Inngår i: The 8th Nordic Wood Biorefinery Conference: NWBC 2018 : proceedings / [ed] Hytönen Eemeli, Vepsäläinen Jessica, Espoo: VTT , 2018, s. 85-89Konferansepaper (Fagfellevurdert)
  • 25.
    Anheden, Marie
    et al.
    RISE - Research Institutes of Sweden, Bioekonomi.
    Uhlin, Anders
    RISE - Research Institutes of Sweden, Bioekonomi.
    Wolf, Jens
    RISE - Research Institutes of Sweden, Bioekonomi.
    Hedberg, Martin
    RISE - Research Institutes of Sweden, Biovetenskap och material, Yta, process och formulering.
    Berg, Robert
    RISE - Research Institutes of Sweden, Biovetenskap och material, Yta, process och formulering.
    Ankner, Tobias
    RISE - Research Institutes of Sweden, Biovetenskap och material, Yta, process och formulering.
    Berglin, Niklas
    NiNa Innovation, Sweden; ÅF Industry, Sweden.
    von Schenck, Anna
    NiNa Innovation, Sweden; ÅF Industry, Sweden.
    Larsson, Anders L
    Valmet AB, Sweden.
    Guimaraes, Matheus
    Fibria, Sweden.
    Fiskerud, Maria
    Karlstad Airport, Sweden.
    Andersson, Stefan
    RISE - Research Institutes of Sweden, Bioekonomi.
    Value chain for production of bio-oil from kraft lignin for use as bio-jet fuel2017Inngår i: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017: NWBC 2017, Stockholm: RISE Bioekonomi , 2017, s. 104-109Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The LignoJet project aimed to achieve an intermediate lignin-oil product miscible with fossil feedstock and with a significantly reduced oxygen content. A technical concept for production has been studied that involves combined catalysed depolymerisation and hydrodeoxygenation, so called hydrogenolytic depolymerisation, of kraft lignin. Kraft lignin was separated through membrane ultrafiltration from softwood and eucalyptus black liquor followed by precipitation through LignoBoost technology. A difference in lignin properties was observed between ultrafiltration of softwood and eucalyptus black liquor through 15 and 150kDa ceramic membranes. Lignin-oils with similar oxygen content were produced regardless of origin and fractionation technique. A lignin-oil with favourable properties as precursor for refinery integration for jet fuel production as produced in small-scale batch experiments using nickel-based catalyst. Stable pumpable oils with melting point of less than 25-50 deg C and with 20-30% lower oxygen content and aromatic content were obtained that would be suitable as jet fuel precursors. The estimated production cost was found to be competitive with that of other liquid biofuels, while additional revenues could potentially be achieved by also producing chemical and materials from suitable fractions of the lignin-oil.

    Fulltekst (pdf)
    fulltext
  • 26.
    Ankerfors, Caroline
    et al.
    RISE - Research Institutes of Sweden, Bioekonomi, Papperstillverkning och förpackningar.
    Gimåker, Magnus
    RISE - Research Institutes of Sweden, Bioekonomi, Papperstillverkning och förpackningar.
    Östlund, Ida
    RISE - Research Institutes of Sweden, Bioekonomi, Papperstillverkning och förpackningar.
    Polyelectrolyte Multilayers and Other Dosage Strategies: Effects on Properties of Paper Sheets Produced in Pilot Scale Using MillProcess Waters2018Inngår i: Paper Conference and Trade Show, PaperCon 2018: Shaping the future through innovation, TAPPI , 2018, Vol. 2, s. 658-669, artikkel-id PA3.3Konferansepaper (Annet vitenskapelig)
  • 27.
    Ankerfors, Mikael
    et al.
    RISE., Innventia.
    Aulin, Christian
    RISE., Innventia.
    Lindström, Tom
    RISE., Innventia.
    Nanocellulose research and developments at Innventia2011Konferansepaper (Fagfellevurdert)
  • 28.
    Ankerfors, Mikael
    et al.
    RISE., Innventia.
    Duker, Elisabeth
    BillerudKorsnäs AB, Sweden.
    Lindström, Tom
    RISE., Innventia.
    Topo-chemical modification of fibres by grafting of carboxymethyl cellulose in pilot scale2013Inngår i: Nordic Pulp and Paper Research Journal, ISSN 0283-2631 , nr 1, s. 6-14Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study was to graft carboxymethyl cellulose (CMC) on to bleached softwood kraft pulp at temperatures below 100°C and to do a pilot paper machine trial in order to examine the influence of the CMC on dewatering, sheet formation and mechanical properties. During the pilot trial, one CMC grafted pulp was compared to a pulp with 3 different refining degrees. It was shown that CMC-grafting improves the mechanical properties of paper with only a minor effect on the sheet density. It was also shown that the CMC grafting is less detrimental to dewatering than refining and at a certain tensile index a higher dry content after pressing could be reached. The formation number of the paper produced in the FEX trial was not significantly affected by the addition of CMC.

  • 29.
    Ankerfors, Mikael
    et al.
    BillerudKorsnäs AB, Sweden.
    Lindström, Tom
    RISE., Innventia.
    Glad Nordmark, Gunborg
    RISE., Innventia.
    Multilayer assembly onto pulp fibres using oppositely charged microfibrillated celluloses, starches, and wetstrength resins: Effect on mechanical properties of CTMP-sheets2016Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, nr 1, s. 135-141Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The effects of multilayering of microfibrillar cellulose (MFC) onto a chemi-thermomechanical pulp (CTMP), from which the fines material had been removed, were investigated with regard to the mechanical properties of hand-sheets. In one series of experiments, the CTMP was multilayered with cationic MFC/anionic MFC (C-MFC/A-MFC) at various addition levels and sheets made in a conventional sheet former, pressed, and dried at room temperature. This experimental series was complemented with a second series, where sheets were made in a Rapid Köthen sheet former. In a third series of experiments, the CTMP was multilayered using a cationic polyamideamine epichlorohydrine resin (PAE) and an AMFC. Sheets were formed using the Rapid Köthen sheet former. Finally, in a fourth series of experiments, the MFC multilayering experiments were compared with multilayering experiments using cationic starch/anionic starch (C-starch/A-Starch). MFC-multilayering (C-MFC/A-MFC) gave inferior strength gain at a low addition level compared to starch multilayering, but (compared on a weight basis) the strength seemed to level off using starches at high addition levels, whereas there were a continuous increase in strength using MFC multilayering. Multilayering using PAE/A-MFC was found to give a higher strength gain than both C-MFC/A-MFC and C-starch/A-starch multilayering. Sheet density was slightly affected (<14%) by the multilayering techniques used in these experiments.

  • 30.
    Ankerfors, Mikael
    et al.
    ÅF Industry, Sweden.
    Lindström, Tom
    RISE - Research Institutes of Sweden, Bioekonomi.
    Glad Nordmark, Gunborg
    RISE - Research Institutes of Sweden, Bioekonomi.
    The effects of different types of wet-end added microfibrillated celluloses on the properties of paper made from bleached kraft pulp2017Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 32, nr 3, s. 336-345Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Research has been undertaken to compare the effects of different types of microfibrillated cellulose (MFC) on the mechanical properties of paper. Three types of MFC were produced: Enzyme MFC (low anionic charge density), Carboxymethylated MFC (high anionic charge density) and cationic MFC (high cationic charge density). The different MFCs required different retention aid strategies. The simplest retention strategy was selected to secure a high retention of MFC. Some experiments also focused on dewatering and pressability of wet webs with carboxymethylated MFC. Conventional isotropic laboratory handsheets were made using a never-dried unrefined elemental chlorine free (ECF)-bleached softwood kraft pulp. It has been shown that the evolution of the mechanical properties and scattering coefficients when plotted versus MFC content was very similar for the three types. However, Enzyme MFC gave a significantly better reinforcement effect. All three types of MFC had a similar effect on the sheet consolidation, reflected in sheet density. Evaluation of the dewatering and pressability of the wet sheets showed that if the MFC was aggregated by an appropriate retention strategy, the dewatering and pressability were not detrimental to the practical applicability of MFC.

  • 31.
    Ankerfors, Mikael
    et al.
    BillerudKorsnäs AB, Sweden.
    Lindström, Tom
    RISE., Innventia.
    Söderberg, L. Daniel
    KTH Royal Institute of Technology, Sweden.
    The use of microfibrillated cellulose in fine paper manufacturing: Results from a pilot scale papermaking trial2014Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 29, nr 3, s. 476-483Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this work the strength enhancing capabilities of microfibrillated cellulose (MFC) in highly filled papers was studied. Both the MFC production and the paper making were done in pilot scale under realistic industrial conditions. The results clearly show that MFC (2.5-5.0 wt-%) could improve the mechanical properties of highly filled papers (20-35 wt-% filler contents). All studied dry mechanical properties were improved and the improvements were most pronounced for Z-strength and fracture toughness. By combining the MFC with a C-starch dosage further improvements in mechanical properties could be achieved. The improvements in mechanical properties enabled increased filler content with retained properties. The filler increase could be achieved at the same time as the sheet formation and the dry content after pressing were improved.

  • 32.
    Ankerfors, Mikael
    et al.
    RISE., Innventia.
    Lindström, Tom
    RISE., Innventia.
    Söderberg, L. Daniel
    RISE., Innventia. KTH Royal Institute of Technology, Sweden.
    The use of microfibrillated cellulose in high filler fine papers2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The field of communication, printing and writing papers has become an increasingly competitive field during the latest years as the market demand of printing and writing papers and newsprint has finally started to decline in the developed economies. One obvious approach to stay competitive is to increase the filler content of such papers. High filler paper is not a new idea and numerous approaches have been tested over the years to produce such papers. In order to reach industrial implementation, pilot-scale research and development under industrial conditions is necessary as a step after laboratory studies. Therefore an environment has been developed in order to perform projects targeting existing technologies for high filler applications as well as the new possibilities incurred by e.g. microfibrillated cellulose.

  • 33.
    Ansari, Farhan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Lindh, Erik L.
    RISE., Innventia. KTH Royal Institute of Technology, Sweden.
    Furo, Istvan
    KTH Royal Institute of Technology, Sweden.
    Johansson, Mats K. G.
    KTH Royal Institute of Technology, Sweden.
    Berglund, Lars A.
    KTH Royal Institute of Technology, Sweden.
    Interface tailoring through covalent hydroxyl-epoxy bonds improves hygromechanical stability in nanocellulose materials2016Inngår i: Composites Science And Technology, ISSN 0266-3538, E-ISSN 1879-1050, Vol. 134, s. 175-183Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Wide-spread use of cellulose nanofibril (CNF) biocomposites and nanomaterials is limited by CNF moisture sensitivity due to surface hydration. We report on a versatile and scalable interface tailoring route for CNF to address this, based on technically important epoxide chemistry. Bulk impregnation of epoxide-amine containing liquids is used to show that CNF hydroxyls can react with epoxides at high rates and high degree of conversion to form covalent bonds. Reactions take place inside nanostructured CNF networks under benign conditions, and are verified by solid state NMR. Epoxide modified CNF nanopaper shows significantly improved mechanical properties under moist and wet conditions. High resolution microscopy is used in fractography studies to relate the property differences to structural change. The cellulose-epoxide interface tailoring concept is versatile in that the functionality of molecules with epoxide end-groups can be varied over a wide range. Furthermore, epoxide reactions with nanocellulose can be readily implemented for processing of moisture-stable, tailored interface biocomposites in the form of coatings, adhesives and molded composites.

  • 34.
    Ansari, Farhan
    et al.
    KTH Royal Institute of Technology, Sweden.
    Sjöstedt, Anna
    KTH Royal Institute of Technology, Sweden.
    Larsson, Per Tomas
    RISE., Innventia. KTH Royal Institute of Technology, Sweden.
    Berglund, Lars A.
    KTH Royal Institute of Technology, Sweden.
    Wågberg, Lars
    KTH Royal Institute of Technology, Sweden.
    Hierarchical wood cellulose fiber/epoxy biocomposites: Materials design of fiber porosity and nanostructure2015Inngår i: Composites. Part A, Applied science and manufacturing, ISSN 1359-835X, E-ISSN 1878-5840, Vol. 74, s. 60-68Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Delignified chemical wood pulp fibers can be designed to have a controlled structure of cellulose fibril aggregates to serve as porous templates in biocomposites with unique properties. The potential of these fibers as reinforcement for an epoxy matrix (EP) was investigated in this work. Networks of porous wood fibers were impregnated with monomeric epoxy and cured. Microscopy images from ultramicrotomed cross sections and tensile fractured surfaces were used to study the distribution of matrix inside and around the fibers - at two different length scales. Mechanical characterization at different relative humidity showed much improved mechanical properties of biocomposites based on epoxy-impregnated fibers and they were rather insensitive to surrounding humidity. Furthermore, the mechanical properties of cellulose-fiber biocomposites were compared with those of cellulose-nanofibril (CNF) composites; strong similarities were found between the two materials. The reasons for this, some limitations and the role of specific surface area of the fiber are discussed.

  • 35. Antonsson, S.
    et al.
    Mäkelä, Petri
    RISE., Innventia.
    Fellers, Christer
    RISE., Innventia.
    Lindström, M. E.
    Comparison of the physical properties of hardwood and softwood pulps2009Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 24, nr 4, s. 409-414Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High mechano-sorptive creep resistance, i.e., good creep resistance in environments with changing relative humidity, is one of the key requirements for linerboards. The aim of this study was to investigate the influence of pulp types and pulp properties on the mechano-sorptive creep of kraftliner. A high-yield softwood, kraftliner pulp, and four different hardwood pulps were investigated. The physical properties of laboratory sheets were evaluated, with emphasis on the mechanosorptive creep properties. The results showed that the density increase due to increased beating significantly improved the tensile stiffness of all pulps, while its effect on the isocyclic creep stiffness was less pronounced. The hardwood pulps showed higher tensile stiffness, better mechano-sorptive creep properties, and lower hygroexpansion than the softwood pulp at a given density. However, the softwood pulp did exhibit better tensile strength and fracture toughness properties than the hardwood pulps. The results imply that hardwood pulps can be competitive with softwood pulps in kraftliners, provided that their tensile strength and fracture toughness properties can be improved by, for example, chemical means. Furthermore, the isocyclic creep stiffness correlates with the ratio of tensile stiffness to hygroexpansion, indicating that this ratio can be used for engineering estimates of the mechano-sorptive creep performance of paper materials.

  • 36. Antonsson, S.
    et al.
    Pulkkinen, I.
    Fiskari, J.
    Karlström, Katarina
    RISE., Innventia.
    Lindström, M.E
    The relationship between hygroexpansion, tensile stiffness, and mechano-sorptive creep in bleached hardwood kraft pulps2010Inngår i: Appita journal, ISSN 1038-6807, Vol. 63, nr 3, s. 231-234Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hygroexpansion coefficient and tensile stiffness are important parameters in many paper applications. This study compares several bleached industrial hardwood kraft pulps, comprising five eucalypt pulps from South America, Europe, and Africa as well as an acacia pulp from Asia and a birch pulp from Scandinavia. Refined and unrefined pulps are compared. The results indicate significant differences in hygroexpansion but smaller differences in tensile stiffness index at comparable densities. No single factor offering a reasonable explanation of these differences in hygroexpansion coefficient, such as carbohydrate composition, fibre dimensions, or fibre form, was found. However, correlation between hygroexpansion coefficient and the mechano-sorptive creep stiffness was observed. We suggest that the hygroexpansion coefficient at a given tensile stiffness level can be used to rank pulps in terms of their mechano-sorptive creep properties.

  • 37.
    Argyropoulos, Dimitris
    et al.
    North Carolina State University, USA.
    Crestini, Claudia
    Ca’ Foscari University of Venice, Italy.
    Dahlstrand, Christian
    Ren FuelK2B AB, Sweden.
    Furusjö, Erik
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Bioraffinaderi och energi. Luleå University of Technology, Sweden.
    Gioia, Claudio
    Universityof Trento, Italy.
    Jedvert, Kerstin
    RISE Research Institutes of Sweden, Material och produktion, Polymera material och kompositer.
    Henriksson, Gunnar
    KTH Royal Institute of Technology, Sweden.
    Hulteberg, Christian
    Lund University, Sweden.
    Lawoko, Martin
    KTH Royal Institute of Technology, Sweden.
    Pierrou, Clara
    RenFuel Materials AB, Sweden.
    Samec, Joseph
    RenFuel Materials AB, Sweden; Stockholm University, Sweden; Chulalongkorn University, Thailand; Ren FuelK2B AB, Sweden.
    Subbotina, Elena
    Yale University, USA.
    Wallmo, Henrik
    Valmet AB, Sweden.
    Wimby, Martin
    Valmet AB, Sweden.
    Kraft Lignin: A Valuable, Sustainable Resource, Opportunities and Challenges.2023Inngår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, artikkel-id e202300492Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Kraft lignin, a by-product from the production of pulp, is currently incinerated in the recovery boiler during the chemical recovery cycle, generating valuable bioenergy and recycling inorganic chemicals to the pulping process operation. Removing lignin from the black liquor or its gasification lowers the recovery boiler load enabling increased pulp production. During the past ten years, lignin separation technologies have emerged and the interest of the research community to valorize this underutilized resource has been invigorated. The aim of this review is to give (1) a dedicated overview of the kraft process with a focus on the lignin, (2) an overview of applications that are being developed, and (3) a techno-economic and life cycle asseeements of value chains from black liquor to different products. Overall, it is anticipated that this effort will inspire further work for developing and using kraft lignin as a commodity raw material for new applications undeniably promoting pivotal global sustainability concerns.

  • 38.
    Asta, Nadia
    et al.
    KTH Royal institute of Technology, Sweden.
    Reid, Michael S.
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign. KTH Royal institute of Technology, Sweden.
    Pettersson, Torbjörn
    KTH Royal institute of Technology, Sweden.
    Wågberg, Lars
    KTH Royal institute of Technology, Sweden.
    The Use of Model Cellulose Materials for Studying Molecular Interactions at Cellulose Interfaces2023Inngår i: ACS Macro Letters, E-ISSN 2161-1653, Vol. 12, s. 1530-1535Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite extensive research on biobased and fiber-based materials, fundamental questions regarding the molecular processes governing fiber-fiber interactions remain unanswered. In this study, we introduce a method to examine and clarify molecular interactions within fiber-fiber joints using precisely characterized model materials, i.e., regenerated cellulose gel beads with nanometer-smooth surfaces. By physically modifying these materials and drying them together to create model joints, we can investigate the mechanisms responsible for joining cellulose surfaces and how this affects adhesion in both dry and wet states through precise separation measurements. The findings reveal a subtle balance in the joint formation, influencing the development of nanometer-sized structures at the contact zone and likely inducing built-in stresses in the interphase. This research illustrates how model materials can be tailored to control interactions between cellulose-rich surfaces, laying the groundwork for future high-resolution studies aimed at creating stiff, ductile, and/or tough joints between cellulose surfaces and to allow for the design of high-performance biobased materials. 

  • 39.
    Athley, Karin
    et al.
    RISE., Innventia.
    Granlöf, Lars
    RISE., Innventia.
    Söderberg, Daniel
    RISE., Innventia.
    Ström, Göran
    RISE., Innventia.
    Optimizing the benefit of retention chemicals2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Pre-flocculation of filler has been tested as a concept for improving the retention of filler and the strength properties of the sheet. The impact of the size of the filler floes on the mechanical retentionin a fibre network was investigated using a modified laboratory hand sheet former. The mechanical retention was found to increase linearly with both particle size and grammage of the fibre web. These results were confirmed in a full scale production trial on the FEX pilot paper machine at Innventia. Here different filler floe sizes were created through different chemical pre-flocculation strategies. The particle size in the flow to the headbox was measured with FBRM, and a linear relation between particle size and filler retention was found. Corresponding linear relation was seen in a pilot trial when adding filler and retention aid conventionally. This implies that mechanical retention constitute an important part of the filler retention not only upon pre-flocculation but also with conventional addition of filler and retention aid. Thus, the particle size before the headbox can be a good indicator of the retention level. For the conventional application of a two component retention aid system, the increased filler retention correlated to impaired formation and decreased sheet strength. On the contrary, pre-flocculation led to an increase in both sheet strength and filler retention, demonstrating the advantage of pre-flocculating filler.

  • 40.
    Athley, Karin
    et al.
    RISE., Innventia.
    Granlöf, Lars
    RISE., Innventia.
    Söderberg, L. Daniel
    RISE., Innventia.
    Ankerfors, Mikael
    RISE., Innventia.
    Ström, Göran R.
    RISE., Innventia.
    Mechanical retention - Influence of filler floc size and grammage of the fibre web2012Inngår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 27, nr 2, s. 202-207Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An investigation of the impact of particle size on the mechanical retention of particles in a fibre network has been conducted. The particles used were five sets of quartz particle fractions having fairly narrow particle size distributions with average particle size ranging from a few μm to around 100 μm. The particles were used to model flocculated filler aggregates as part of a larger study of the effect of pre-flocculation on mechanical retention. Pre-flocculation of the filler is a possible strategy to increase the filler content of paper without deterioration of strength properties. A modified laboratory hand sheet former, known as the Rapid Drainage Device (RDD) was used. The major modification consisted of a long pipe that acted as a suction leg, which provides a dewatering vacuum at the same level as on a paper machine. The experimental results showed that mechanical filler retention increased linearly with particle size and grammage of the fibre layer above a critical grammage which depended on particle size. The linear relation was also seen in a pilot scale trial on the FEX pilot-paper machine at Innventia. During this trial fine paper was produced using pre-flocculated filler where the mean particle size of the flocs and fibres was measured in the flow to the headbox. The results from this pilot trial show that mechanical retention is an important part of the total filler retention. Drainage time and therefore drainage resistance increased with the grammage of the fibre layer and amount of quartz particle added. Drainage time, compared at total grammage (i.e. the sum of fibre and quartz particle grammage) was lowest for a fraction of medium-sized particles, with a median size of 35 μm. There was no obvious effect on retention or drainage resistance of a change in the dewatering pressure from 27.5 to 41.5 kPa.

  • 41. Aulin, Christian
    et al.
    Gällstedt, Mikael
    RISE., Innventia.
    Lindström, Tom
    RISE., Innventia.
    Oxygen and oil barrier properties of microfibrillated cellulose films and coatings2010Inngår i: Cellulose, ISSN 0969-0239, E-ISSN 1572-882X, Vol. 17, nr 3, s. 559-574Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The preparation of carboxymethylated microfibrillated cellulose (MFC) films by dispersion-casting from aqueous dispersions and by surface coating on base papers is described. The oxygen permeability of MFC films were studied at different relative humidity (RH). At low RH (0%), the MFC films showed very low oxygen permeability as compared with films prepared from plasticized starch, whey protein and arabinoxylan and values in the same range as that of conventional synthetic films, e.g., ethylene vinyl alcohol. At higher RH’s, the oxygen permeability increased exponentially, presumably due to the plasticizing and swelling of the carboxymethylated nanofibers by water molecules. The effect of moisture on the barrier and mechanical properties of the films was further studied using water vapor sorption isotherms and by humidity scans in dynamic mechanical analysis. The influences of the degree of nanofibrillation/dispersion on the microstructure and optical properties of the films were evaluated by field-emission scanning electron microscopy (FE-SEM) and light transmittance measurements, respectively. FE-SEM micrographs showed that the MFC films consisted of randomly assembled nanofibers with a thickness of 5-10 nm, although some larger aggregates were also formed. The use of MFC as surface coating on various base papers considerably reduced the air permeability. Environmental scanning electron microscopy (E-SEM) micrographs indicated that the MFC layer reduced sheet porosity, i.e., the dense structure formed by the nanofibers resulted in superior oil barrier properties.

  • 42.
    Aulin, Christian
    et al.
    RISE., Innventia.
    Lindström, Tom
    RISE., Innventia.
    Biopolymer Coatings for Paper and Paperboard2011Inngår i: Biopolymers: New Materials for Sustainable Films and Coatings / [ed] Plackett David, John Wiley & Sons, 2011, s. 255-276Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 43.
    Aulin, Christian
    et al.
    RISE., Innventia. KTH Royal Institute of Technology, Sweden.
    Ström, Göran R.
    RISE., Innventia.
    Multilayered alkyd resin/nanocellulose coatings for use in renewable packaging solutions with a high level of moisture resistance2013Inngår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, nr 7, s. 2582-2589Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A surprisingly simple and rapid methodology for large-area, lightweight, and thin laminate coatings with remarkable moisture barrier properties is introduced. Commercially available paperboards are coated with thin layers of nanocellulose. The nanocellulose coating induces a surface smoothening effect on the coated sheets as characterized by environmental scanning electron microscopy and white light interferometry. A moisture-protective layer of renewable alkyd resins is deposited on the nanocellulose precoated sheets using a water-borne dispersion coating process or lithographic printing. Through an auto-oxidation process, the applied alkyd resins are transformed into moisture sealant layers. The moisture barrier properties are characterized in detail by water vapor permeability measurements at different levels of relative humidity. The water vapor barrier properties of the nanocellulose precoated substrates were significantly improved by thin layers of renewable alkyd resins. The effect of the alkyd resin properties, coating technologies, and base paper substrates on the final barrier performance of the sheets were studied. It was found that the nanocellulose coating had a notable effect on the homogeneity and barrier performance of the alkyd resin layers and in particular those alkyd resin layers that were applied by printing. The concept is environmentally friendly, energy-efficient, and economic and is ready for scaling-up via continuous roll-to-roll processes. Large-scale renewable coatings applicable for sustainable packaging solutions are foreseen.

  • 44.
    Axegard, P.
    et al.
    RISE., Innventia.
    Bergnor, E.
    RISE., Innventia.
    Environmental performance of modern ECF bleaching2011Konferansepaper (Fagfellevurdert)
  • 45.
    Axegård, Peter
    RISE - Research Institutes of Sweden, Bioekonomi.
    The biorefinery pulp mill2017Inngår i: Biofor International, February 13-17, 2017, Montreal, Canada, 2017Konferansepaper (Annet vitenskapelig)
    Download (pdf)
    presentationsbild
  • 46.
    Axegård, Peter
    RISE., Innventia.
    The kraft pulp mill bio-refinery2013Konferansepaper (Fagfellevurdert)
  • 47.
    Axegård, Peter
    et al.
    RISE., Innventia.
    Berglin, Niklas
    RISE., Innventia.
    Lindgren, Karin
    RISE., Innventia.
    Tomani, Per
    RISE., Innventia.
    Öhman, Fredrik
    RISE., Innventia.
    The kraft pulp mill biorefinery platform2011Konferansepaper (Fagfellevurdert)
  • 48.
    Babi, Mouhanad
    et al.
    McMaster University, USA.
    Fatona, Ayodele
    McMaster University, USA.
    Li, Xiang
    McMaster University, USA.
    Cerson, Christine
    McMaster University, USA.
    Jarvis, Victoria M.
    McMaster University, USA.
    Abitbol, Tiffany
    RISE Research Institutes of Sweden.
    Moran-Mirabal, Jose M.
    McMaster University, USA.
    Efficient Labeling of Nanocellulose for High-Resolution Fluorescence Microscopy Applications2022Inngår i: Biomacromolecules, ISSN 1525-7797, E-ISSN 1526-4602, Vol. 23, nr 5, s. 1981-1994Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The visualization of naturally derived cellulose nanofibrils (CNFs) and nanocrystals (CNCs) within nanocomposite materials is key to the development of packaging materials, tissue culture scaffolds, and emulsifying agents, among many other applications. In this work, we develop a versatile and efficient two-step approach based on triazine and azide-alkyne click-chem. to fluorescently label nanocelluloses with a variety of com. available dyes. We show that this method can be used to label bacterial cellulose fibrils, plant-derived CNFs, carboxymethylated CNFs, and CNCs with Cy5 and fluorescein derivatives to high degrees of labeling using minimal amounts of dye while preserving their native morphol. and crystalline structure. The ability to tune the labeling d. with this method allowed us to prepare optimized samples that were used to visualize nanostructural features of cellulose through super-resolution microscopy. The efficiency, cost-effectiveness, and versatility of this method make it ideal for labeling nanocelluloses and imaging them through advanced microscopy techniques for a broad range of applications.

  • 49.
    Backlund, Birgit
    RISE., Innventia.
    Nya produkter från skogsråvara2014Konferansepaper (Fagfellevurdert)
  • 50.
    Backlund, Birgit
    RISE., Innventia.
    Towards increased closure and energy efficiency2009Inngår i: Pulping Chemistry and Technology, Walter de Gruyter, 2009, s. 363-390Kapittel i bok, del av antologi (Annet vitenskapelig)
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