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  • 101.
    Göransson, Kristina
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Söderlind, Ulf
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Biogas production from biological methanation of syngas2018Ingår i: European Biomass Conference and Exhibition Proceedings, ETA-Florence Renewable Energies , 2018, nr 26thEUBCE, s. 512-515Konferensbidrag (Refereegranskat)
    Abstract [en]

    Biogas to be used as gas vehicle fuel is a highly potential source to meet transport fuel demand and give a significant contribution to the Swedish target: vehicle fleet independent of fossil fuels by 2030. At present the biogas market is limited by the amount of available organic waste and the associated infrastructure. To overcome these issues, biomass could either be gasified into syngas and synthesized into bio-SNG (Synthetic Natural Gas) through catalytic methanation, or biomass gasification could be integrated into the biogas system to produce methane through biological methanation. Biomass gasification integrated in biological methanation is a relatively new idea and technology. Syngas conversion to methane by anaerobic cultures is practically unexplored, and few reports are available on this subject. Nevertheless, the pathway has been receiving intensive attractions and R&D recent years. For this purpose, a novel pathway by integrating biomass gasification into biogas system is studied in detail. This paper reviews the whole process from integration of biomass gasification into the biogas system to methane production through biological methanation: Biomass gasification > H2+CO > Biogas digester > Upgrading > Natural gas network. 

  • 102.
    Göransson, Kristina
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Söderlind, Ulf
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    CATALYTIC REDUCTION OF TAR/CH4 BY AN INTERNAL REFORMER IN A DFB GASIFIER2014Ingår i: European Biomass Conference & Exhibition Proceedings, 2014, s. 620-625Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    An internal reformer is developed for in-situ catalytic reforming of tar and methane (CH4) in allothermal gasifiers. Reduction of tars and CH4 in the syngas is a challenge for commercialization of biomass fluidised-bed gasification technology towards advanced automotive fuel production. This paper presents an initial study on the internal reformer operated with and without Ni-catalytic pellets in the Mid Sweden University (MIUN) DFB (Dual Fluidised Bed) gasifier, by evaluation of the syngas composition and tar/CH4 content. The novelty with the application of Ni-catalyst in this paper is the selected location where intensive gas to catalytic-material and bed-material contacts improve the reforming reactions. It can be concluded that the reformer with Ni-catalytic pellets clearly gives a higher H2 content together with lower CH4 and tar contents in the syngas than the reformer without Ni-catalytic pellets. The gravimetric tar content decreases down to 5 g/m3 and the CH4 content down below 6% in the syngas. The tar content will be decreased further to lower levels, with increased gas contact to the specific surface area of the catalyst and increased catalyst surface-to-volume ratio. The new design in the MIUN gasifier increases the gasification efficiency, suppresses the tar generation and upgrades the syngas quality.  

  • 103.
    Göransson, Kristina
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Söderlind, Ulf
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Internal Tar/CH4 Reforming using a Novel Design in a Biomass Dual Fluidised Bed Gasifier2013Ingår i: 21st European Biomass Conference and Exhibition: Setting the course for a biobased ecomomy, Florence, Italy: ETA-Florence Renewable Energies , 2013, s. 2038-2042Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    Reforming of tars and methane (CH4) in syngas is a significant challenge for low-temperature biomass gasification. For a dual fluidised bed gasifier (DFBG), catalytic bed materials are usually used to promote the reforming reactions. Intensive contact between gas and catalytic bed material at high temperature enhances the internal tar/CH4 reforming. The MIUN gasifier, built for research into synthetic fuel production, is a dual fluidised bed gasifier (DFBG). The results with different bed materials (silica sand, olivine and Fe-impregnated olivine) give roughly equivalent amounts of methane and gravimetric tar in the raw untreated syngas, and need to be reduced to an acceptably low level. The gasification research group at MIUN investigates a novel design in the MIUN gasifier, to increase the gasification efficiency, suppress the tar generation and to upgrade the syngas quality. The first step is taken towards a novel design in the MIUN gasifier. The application is expected to significantly enhance the syngas quality.

  • 104.
    Hammarström, Anton
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Utvärdering av potential för värmeåtervinning från laborationsutrustning: Möjligheten att använda en kylvattenbassäng som termiskt säsongslager2018Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    HETA utbildningar i Härnösand har ett ångkraftverk för undervisningssyfte som kyls ner med vatten från en underjordisk bassäng på cirka 329 m³. Syftet med detta examensarbete har varit att undersöka hur bassängen med spillvärmen från kraftverket kan användas som ett säsongslager i kombination med en befintlig 7,8 kW värmepump för att värma upp maskinhallen i deras laboratoriebyggnad. Ett kalkylark skapades i Microsoft Excel för att kunna genomföra beräkningarna. Då mätdata saknades skapades ett simulerat scenario baserat på temperaturstatistik och körschema för kraftverket från år 2017. Transmissionsförluster beräknades för bassängen och maskinhallen. För bassängen användes mestadels observationsdata och kännedom hos personalen, medan maskinhallens isolering i huvudsak fick uppskattas efter byggår. Resultatet blev att värmepumpen med aktuellt körschema kunde täcka cirka 45 % av maskinhallens årliga uppvärmningsbehov. Av de 276 GJ som tillfördes genom kylning av ångkraftverket under ett år beräknades endast 2,7 % kunna utnyttjas till uppvärmning av maskinhallen, på grund av för lite isolering i bassängen. De största begränsningarna för högre täckning och större nyttjande av spillvärmen bedömdes vara placeringen i tid av kraftverkets körningar, och värmepumpens effekt. Om körningarna skulle förläggas i huvudsak till november–april och värmepumpen ersättas med en på 10 kW, skulle 74 % av värmebehovet kunna täckas och över 18 % av spillvärmen utnyttjas. Andra saker som förbättrad isolering i bassängen och större vattenvolym bedömdes också kunna förbättra bassängens kapacitet som energilager.

  • 105.
    Harvey, Deborah J.
    et al.
    Royal Holloway University of London, UK.
    Harvey, Hannah
    Royal Holloway University of London, UK.
    Harvey, Rachael P.
    UCL, London, England.
    Kadej, Marcin
    Univ Wroclaw, Poland.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Gange, Alan C.
    Royal Holloway University of London, UK.
    Finch, Paul
    Royal Holloway University of London, UK.
    Use of novel attraction compounds increases monitoring success of a rare beetle, Elater ferrugineus2017Ingår i: Insect Conservation and Diversity, ISSN 1752-458X, E-ISSN 1752-4598, Vol. 10, nr 2, s. 161-170Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The use of pheromones to determine distributions of rare saproxylic insects is an increasingly popular technique. Pheromones may, however, also be used to elucidate the biology of these cryptic species, a vital requirement if they are to be accurately monitored and conserved. We used non-invasive aerial trapping to compare the effectiveness of chemicals produced by Elater ferrugineus L (Coleoptera: Elateridae), namely 7-methyloctyl (Z)-4-decenoate (the female-produced sex pheromone), and male compounds (geranyl and neryl acetone and 6-methyl-5-heptene-2-one). The male compounds were identified using headspace analysis by solid phase micro-extraction gas chromatography-mass spectrometry. We discovered that males only produce these two compounds after having been attracted to a female, and that this serves to attract further males to a female. Such compounds do not appear to attract females but for a species that has a short activity period and is non-feeding in the adult stage, may ensure breeding success when populations are low. By marking all beetles caught, we were able to demonstrate that recapture rate using this method is low (approximately 11% of total captures annually). Therefore, the method does not limit dispersal or breeding opportunities, making it a valuable tool for monitoring endangered saproxylic beetle species.

  • 106.
    Harvey, Deborah J.
    et al.
    School of Biological Sciences, Royal Holloway University of London, Egham, UK.
    Harvey, Hannah
    School of Biological Sciences, Royal Holloway University of London, Egham, UK.
    Larsson, Mattias C.
    Swedish University of Agricultural Sciences, Alnarp.
    Svensson, Glenn P.
    Lund University, Lund.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Finch, Paul
    School of Biological Sciences, Royal Holloway University of London, Egham, UK.
    Gange, Alan C.
    School of Biological Sciences, Royal Holloway University of London, Egham, UK.
    Making the invisible visible: Determining an accurate national distribution of Elater ferrugineus in the United Kingdom using pheromones2017Ingår i: Insect Conservation and Diversity, ISSN 1752-458X, E-ISSN 1752-4598, Vol. 10, nr 4, s. 1-11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To date, conservation-status saproxylic beetle species in the UK have been monitored by chance findings or by monitor-based observational studies. Here, using Elater ferrugineus as our target species, we present the first national distribution survey carried out in the UK or across mainland Europe on such a species using chemicals produced by the insect. Over 3 years, mark-release-recapture studies were performed across the UK, using 416 lured (pheromone) traps monitored by volunteer recorders; the first survey in Europe to do so. Traps were baited with 7-methyloctyl- (Z)-4-decenoate, a compound previously identified as a female sex pheromone. The results were used to plot a distribution map and investigate factors that may influence the distribution, including summer temperatures, possible habitat availability and larval food source. The survey revealed a south-eastern distribution of E. ferrugineus in the UK, which was suggested by previous casual studies. A correlative model was fitted to the data, indicating that 55% of the variation in the distribution of E. ferrugineus was explained by climatic variables (temperature and wind speed).

  • 107.
    He, Jie
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Gasification-based Biorefinery for Mechanical Pulp Mills2014Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    The modern concept of “biorefinery” is dominantly based on chemical pulp mills to create more value than cellulose pulp fibres, and energy from the dissolved lignins and hemicelluloses. This concept is characterized by the conversion of biomass into various bio-based products. It includes thermochemical processes such as gasification and fast pyrolysis. In thermo-mechanical pulp (TMP) mills, the feedstock available to the gasification-based biorefinery is significant, including logging residues, bark, fibre material rejects, bio-sludges and other available fuels such as peat, recycled wood and paper products. On the other hand, mechanical pulping processes consume a great amount of electricity, which may account for up to 40% of the total pulp production cost. The huge amount of purchased electricity can be compensated for by self-production of electricity from gasification, or the involved cost can be compensated for by extra revenue from bio-transport fuel production. This work is to study co-production of bio-automotive fuels, bio-power, and steam via gasification of the waste biomass streams in the context of the mechanical pulp industry. Ethanol and substitute natural gas (SNG) are chosen to be the bio-transport fuels in the study. The production processes of biomass-to-ethanol, SNG, together with heat and power, are simulated with Aspen Plus. Based on the model, the techno-economic analysis is made to evaluate the profitability of bio-transport fuel production when the process is integrated into a TMP mill.The mathematical modelling starts from biomass gasification. Dual fluidized bed gasifier (DFBG) is chosen for syngas production. From the model, the yield and composition of the syngas and the contents of tar and char can be calculated. The model has been evaluated against the experimental results measured on a 150

    KWth Mid Sweden University (MIUN) DFBG. As a reasonable result, the tar content in the syngas decreases with the gasification temperature and the steam to biomass (S/B) ratio. The biomass moisture content is a key parameter for a DFBG to be operated and maintained at a high gasification temperature. The model suggests that it is difficult to keep the gasification temperature above 850 ℃ when the biomass moisture content is higher than 15.0 wt.%. Thus, a certain amount of biomass or product gas needs to be added in the combustor to provide sufficient heat for biomass devolatilization and steam reforming.For ethanol production, a stand-alone thermo-chemical process is designed and simulated. The techno-economic assessment is made in terms of ethanol yield, synthesis selectivity, carbon and CO conversion efficiencies, and ethanol production cost. The calculated results show that major contributions to the production cost are from biomass feedstock and syngas cleaning. A biomass-to-ethanol plant should be built over 200 MW.In TMP mills, wood and biomass residues are commonly utilized for electricity and steam production through an associated CHP plant. This CHP plant is here designed to be replaced by a biomass-integrated gasification combined cycle (BIGCC) plant or a biomass-to-SNG (BtSNG) plant including an associated heat & power centre. Implementing BIGCC/BtSNG in a mechanical pulp production line might improve the profitability of a TMP mill and also help to commercialize the BIGCC/BtSNG technologies by taking into account of some key issues such as, biomass availability, heat utilization etc.. In this work, the mathematical models of TMP+BIGCC and TMP+BtSNG are respectively built up to study three cases: 1) scaling of the TMP+BtSNG mill (or adding more forest biomass logging residues in the gasifier for TMP+BIGCC); 2) adding the reject fibres in the gasifier; 3) decreasing the TMP SEC by up to 50%.The profitability from the TMP+BtSNG mill is analyzed in comparison with the TMP+BIGCC mill. As a major conclusion, the scale of the TMP+BIGCC/BtSNG mill, the prices of electricity and SNG are three strong factors for the implementation of BIGCC/BtSNG in a TMP mill. A BtSNG plant associated to a TMP mill should be built in a scale above 100 MW in biomass thermal input. Comparing to the case of TMP+BIGCC, the NR and IRR of TMP+BtSNG are much lower. Political instruments to support commercialization of bio-transport fuel are necessary.

     

  • 108.
    He, Jie
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Björkqvist, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Techno-economic evaluation of a mechanical pulp mill with gasification2013Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 28, nr 3, s. 349-357Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Mechanical pulping processes, including thermomechanical pulp (TMP), groundwood (SGW andPGW), and chemithermomechanical pulp (CTMP) processes, each have a very high wood-to-pulp yield. Producing pulp by means of these processes is a prerequisite for paper (such as printing paper and paperboard) grades requiring high printability and stiffness. However, mechanical pulping processes consume a great amount of electricity, which may account for up to 40% of the total pulp production cost.

    In mechanical pulping mills, wood (biomass) residues are commonly utilized for electricity production through an associated combined heat and power (CHP) plant. This techno-economic evaluation deals with the possibility of utilizing a biomass integrated gasification combined cycle (BIGCC) plant in place of the CHP plant.

    Implementing BIGCC in a mechanical pulp production line might greatly improve the overall energy efficiency and cost-effectiveness, especially when more biomass from forest (such as branches and tree tops) is available. When the fibre material that negatively affects pulp properties is utilized as a bioenergy resource, the overall efficiency will be further improved. A TMP+BIGCC mathematical model is developed with ASPEN Plus. By means of modeling, three cases are studied:

    1) adding more forest biomass logging residues in the gasifier,2) adding the reject fibres in the gasifier, and3) decreasing the TMP-specific electricity consumption (SEC) by up to 50%.

    For a TMP+BIGCC mill, the energy supply and consumption are analyzed in comparison with a TMP+CHP mill. The production profits are evaluated.

  • 109.
    He, Jie
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bio-SNG production in a TMP Mill in comparison with BIGCC2014Ingår i: Energy Procedia, Elsevier, 2014, Vol. 61, s. 2894-2897Konferensbidrag (Refereegranskat)
    Abstract [en]

    Biorefinery as a concept for polygeneration of various bio-based materials, fuels and chemicals has been more and more attractive. This concept is applied to the thermomechanical pulp (TMP) and paper industry in the present study to evaluate the possibility of co-production of substitute natural gas (SNG), electricity and district heating (DH) in addition to mechanical pulp and paper. In TMP mills, wood and biomass residues are commonly utilized for electricity and steam production through an associated combined heat and power (CHP) plant. This CHP plant is designed to be replaced by a biomass-T o-SNG (BtSNG) plant including an associated heat and power centre. Implementing BtSNG in a mechanical pulp production line might improve the profitability of a TMP mill and also help to commercialize the BtSNG technology by taking into account of some key issues such as, biomass availability, heat utilization etc. A TMP+BtSNG mathematical model is developed with ASPEN Plus.

  • 110.
    Hedenström, Erik
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Andersson, Fredrik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Sjöberg, Natalia
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Eltz, Thomas
    Ruhr University Bochum, Bochum, Germany.
    6-(4-Methylpent-3-en-1-yl)naphthalene-1,4-dione, a behaviorally active semivolatile in tibial perfumes of orchid bees2018Ingår i: Chemoecology, ISSN 0937-7409, E-ISSN 1423-0445, Vol. 28, nr 4-5, s. 131-135Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Male neotropical orchid bees (Euglossini) collect volatiles from varied sources in their environment to compile complex, species-specific tibial perfumes, which are later released at mating sites. A major compound prominent in tibial extracts of Euglossa allosticta was purified, as well as isolated and its structure was elucidated by analytical methods including GC–MS, GC–FTIR, HRMS and 1H and 13C NMR. After synthesis, the compound with the proposed structure was finally identified as 6-(4-methylpent-3-en-1-yl)naphthalene-1,4-dione. At field sites in Panama and Costa Rica, the synthetic compound attracted males of E. allosticta, but no other euglossines. This strengthens the view that semivolatiles play an important role in conveying specificity to perfume signals of orchid bees. 

  • 111.
    Hedenström, Erik
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Fagerlund-Edfeldt, Amelie
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edman, Mattias
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Jonsson, Bengt-Gunnar
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Resveratrol, piceatannol, and isorhapontigenin from Norway spruce (Picea abies) debarking wastewater as inhibitors on the growth of nine species of wood-decaying fungi2016Ingår i: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 50, nr 3, s. 617-629Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The diethyl ether extract obtained from solvent-solvent extraction of Norway spruce (Picea abies) debarking water, a byproduct from debarking of logs in the pulp and paper industry, was tested for inhibition of growth on agar plates of nine species of wood-decaying fungi: Antrodia sinuosa, Antrodia xantha, Coniophora puteana, Fomitopsis pinicola, Gloeophyllum sepiarium, Heterobasidion parviporum, Phlebiopsis gigantea, Serpula himantioides, and Serpula lacrymans. One fraction of the extract showed excellent antifungal activity for a majority of the species, with complete inhibition of growth for A. sinuosa, A. xantha, and G. sepiarium. The major constituents of the most active fraction were identified as the hydroxystilbenes resveratrol, isorhapontigenin (synonymous with methyl piceatannol), and piceatannol (synonymous with astringenin). The active compounds were isolated or synthesized and used individually for dose-response studies. It was found that isorhapontigenin and piceatannol inhibited all growth of A. sinuosa, A. xantha, and G. sepiarium in 0.35 % weight concentration. The hydroxystilbenes were the three most abundant substances in the debarking water and can be obtained as a mixture or in enriched forms. From some extraction steps of the raw debarking water, it would be possible to obtain the hydroxystilbenes in quantities that might be of commercial interest as efficient natural fungicides.

  • 112.
    Hedenström, Erik
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Wallin, Erika
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Andersson, J
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bång, Joakim
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Wang, H-L
    Department of Biology, Lund University, Sölvegatan 37, Lund, Sweden .
    Löfstedt, C
    Department of Biology, Lund University, Sölvegatan 37, Lund, Sweden .
    Brattström, O
    Department of Zoology, Cambridge University, Cambridge, United Kingdom.
    Baquet, P
    Evolutionary Ecology and Genetics group, Biodiversity Research Centre, Earth and Life Institute, Académie Louvain, Croix du Sud 4, Louvain-la-Neuve, Belgium.
    Stereoisomeric Analysis of 6,10,14-Trimethylpentadecan-2-ol and the Corresponding Ketone in Wing Extracts from African Bicyclus Butterfly Species2015Ingår i: Journal of Chemical Ecology, ISSN 0098-0331, E-ISSN 1573-1561, Vol. 41, nr 1, s. 44-51Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Gas chromatography (GC) and mass spectrometry (MS) were used to determine the stereoisomeric compositions of 6,10,14-trimethylpentadecan-2-ol and 6,10,14-trimethylpentadecan-2-one in wing extracts from 17 Bicyclus butterfly species from different regions of Africa. All samples were purified using solid phase extraction (SPE). Since some species contained both alcohol and ketone, these were separated and the ketone was reduced to the alcohol before analysis as either (R)-trans-chrysanthemoyl or (S)-2-acetoxypropionyl esters. A novel asymmetric synthesis was developed for a reference mixture of (2R/S,6S,10R)-6,10,14-trimethylpentadecan-2-ol with known composition of the eight stereoisomers. The mixture then was used as the (R)-trans-chrysanthemoyl esters to correlate each of the eight gas chromatographic peaks to a specific stereoisomer of the extracted wing compounds. Seven butterfly species showed (2R,6R,10R)-configuration of the alcohol, four species contained minute amounts of alcohol too small to determine the stereochemistry, nine species showed (6R,10R)-configuration of the ketone, and one species contained minute amounts of ketone too small to determine the stereochemistry. No other stereoisomers of alcohol or ketone could be detected in the extracts, and the quantities of the compounds in the wing extracts varied from 5 to 900 ng per sample for each species.

  • 113.
    Hedlund, Alexander
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. FrontWay AB.
    Stengard, Anna-Karin
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Sundsvall Energi AB.
    Björkqvist, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    A simulation-based method for evaluation of energy system cooperation between pulp and paper mills and a district heating system: A case study2017Ingår i: 19 World academy of science, engineering and technology conference proceedings, 2017, Vol. 19, s. 1158-1164Konferensbidrag (Refereegranskat)
    Abstract [en]

    A step towards reducing greenhouse gases and energy consumption is to collaborate with the energy system between several industries. This work is based on a case study on integration of pulp and paper mills with a district heating system in Sundsvall, Sweden. 

    Present research shows that it is possible to make a significant reduction in the electricity demand in the mechanical pulping process. However, the profitability of the efficiency measures could be an issue, as the excess steam recovered from the refiners decreases with the electricity consumption. A consequence will be that the fuel demand for steam production will increase. If the fuel price is similar to the electricity price it would reduce the profit of such a project. If the paper mill can be integrated with a district heating system, it is possible to upgrade excess heat from a nearby kraft pulp mill to process steam via the district heating system in order to avoid the additional fuel need. The concept is investigated by using a simulation model describing both the mass and energy balance as well as the operating margin. Three scenarios were analyzed: reference, electricity reduction and energy substitution. The simulation show that the total input to the system is lowest in the Energy substitution scenario. Additionally, in the Energy substitution scenario the steam from the incineration boiler covers not only the steam shortage but also a part of the steam produced using the biofuel boiler, the cooling tower connected to the incineration boiler is no longer needed and the excess heat can cover the whole district heating load during the whole year. 

    The study shows a substantial economic advantage if all stakeholders act together as one system. However, costs and benefits are unequally shared between the actors. This means that there is a need for new business models in order to share the system costs and benefits. 

  • 114.
    Hellström, P.
    et al.
    AkzoNobel Pulp and Performance Chemicals, 445 80 Bohus, Sweden.
    Heijnesson-Hultén, A.
    AkzoNobel Pulp and Performance Chemicals, 445 80 Bohus, Sweden.
    Paulsson, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. AkzoNobel Pulp and Performance Chemicals, 445 80 Bohus, Sweden.
    Håkansson, H.
    Department of Engineering and Chemical Sciences, Karlstad University, 651 88 Karlstad, Sweden .
    Germgård, U.
    Department of Engineering and Chemical Sciences, Karlstad University, 651 88 Karlstad, Sweden .
    The effect of Fenton chemistry on the properties of microfibrillated cellulose2014Ingår i: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 21, nr 3, s. 1489-1503Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A fully bleached birch kraft pulp was treated with acidic hydrogen peroxide in the presence of ferrous ions (Fenton's reagent) and thereafter treated mechanically in a colloid mill to produce a product containing microfibrillated cellulose (MFC). The produced MFC products were chemically and morphologically characterized and compared with MFC products produced without pretreatment as well as with enzymatic hydrolysis. Fenton treatment resulted in an increase in total charge and number of carbonyl groups while the intrinsic viscosity decreased. The Fenton treated pulps were easier to process mechanically i.e. they reached a higher specific surface area at a given mechanical treatment time and the MFC produced had a stable water-fibre suspension for at least 8 weeks compared to enzymatic pretreated pulps and pulps not subjected to any pretreatment. © 2014 Springer Science+Business Media Dordrecht.

  • 115.
    Hellström, Pia
    et al.
    Akzo Nobel Pulp & Paper Performance Chem AB, Bleaching Chem Applicat RD&I, Bohus, Sweden.;Karlstad Univ, Karlstad, Sweden.
    Heijnesson-Hulten, Anette
    Akzo Nobel Pulp & Paper Performance Chem AB, Bleaching Chem Applicat RD&I, Bohus, Sweden.
    Paulsson, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Akzo Nobel Pulp & Performance Chem AB, Bleaching Chem Applicat RD&I, Bohus, Sweden.
    Hakansson, Helena
    Karlstad Univ, Chem Engn, Karlstad, Sweden.
    Germgard, Ulf
    Karlstad Univ, Pulp Technol, Karlstad, Sweden.
    A comparative study of enzymatic and Fenton pretreatment applied to a birch kraft pulp used for MFC production in a pilot scale high-pressure homogenizer2016Ingår i: TAPPI Journal, ISSN 0734-1415, Vol. 15, nr 6, s. 375-381Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microfibrillated cellulose (MFC) was produced in pilot scale from a bleached birch (Betula verrucosa) kraft pulp that was pretreated with either Fenton's reagent or with a combined mechanical and enzymatic method used at the Centre Technique du Papier (CTP; Grenoble, France). The change in fiber fibrillation during the homogenization treatment was monitored by analyzing the fiber and the fines content, size fractionation, rheological properties and visualization by light-and scanning electron microscopy (SEM). The Fenton pretreatment resulted in MFC suspensions that contained a high amount of small sized elements. After five passes through the high-pressure homogenizer, the amount of particles smaller than 20 mu m was 37% for the Fenton pretreated MFC compared to 13% for the enzymatically (endoglucanase) pretreated MFC. Altogether, the Fenton pretreatment enabled preparation of MFC with a higher degree of fibrillation after the same number of passes through the high-pressure homogenizer. Another option is to produce MFC of the same amount of fibrillation as after an enzymatic stage, but at significantly lower energy consumption.

  • 116.
    Hellström, Pia
    et al.
    AkzoNobel Pulp & Performance Chem, SE-44580 Bohus, Sweden.
    Heijnesson-Hultén, Anette
    AkzoNobel Pulp & Performance Chem, SE-44580 Bohus, Sweden.
    Paulsson, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. AkzoNobel Pulp & Performance Chem, SE-44580 Bohus, Sweden.
    Håkansson, Helena
    Karlstad Univ, Dept Engn & Chem Sci, SE-65188 Karlstad, Sweden.
    Germgård, Ulf
    Karlstad Univ, Dept Engn & Chem Sci, SE-65188 Karlstad, Sweden.
    Fenton pre-treated microfibrillated cellulose evaluated as a strength enhancer in the middle ply of paperboard2014Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 29, nr 4, s. 732-740Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microfibrillated celluloses (MFCs), produced by various pre-treatments of a fully bleached birch kraft pulp, were evaluated as strength enhancers in test sheets representing the middle ply of paperboard. The furnish consisted of hydrogen peroxide bleached high temperature spruce chemithermomechanical pulp (HT-CTMP), MFC and a retention system containing cationic starch and an anionic silica sol. The MFC was prepared via a mechanical treatment in a colloid mill after pretreatment with Fenton's reagent, monocomponent endoglucanase or acidic hydrogen peroxide. Addition of 5% MFC, produced with Fenton pre-treatment, resulted in improved HT-CTMP properties with respect to increased tensile index (similar to 35%), z-directional strength (similar to 50%), tensile stiffness index (similar to 25%) compared to HT-CTMP test sheets prepared without MFC addition. The strength improvement was linearly correlated to the density of the tests sheet, to the surface area (BET) and to the surface charge of the enzymatic or chemically pre-treated MFCs.

  • 117.
    Henschel, Till
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Söderlind, Ulf
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    A study on the pyrolysis behaviour of different biomass fuels using thermogravimetry and online gas analysis2016Ingår i: European Biomass Conference and Exhibition Proceedings, ETA-Florence Renewable Energies , 2016, Vol. 24thEUBCE, nr 24thEUBCE, s. 1290-1293Konferensbidrag (Refereegranskat)
    Abstract [en]

    Fuel availability and flexibility are important issues for biomass-based heat/power and advanced biofuel plants. The physical and chemical properties of biomass feedstocks vary from one to others to a great degree, which must be taken care of for the reactor design/operation, system optimization and blend feedstock application. In this work, the biomass property is evaluated based on pyrolysis behavior of biomass fuels by means of TGA and online gas analysis. Wood, pine bark, peat, straw, black liquor and microalgae are chosen as the biomass feedstocks for the pyrolysis study. The measurement results show high volatile content for algae and black liquor (around 85%) and low volatile content for pine bark and peat (around 69%). Differently from woody biomass, the DTG curve of straw has a single dominant peak at much lower temperature, which suggests a dominant component of hemicellulose in biomass, while algae and peat have a broader temperature specturm of devolatilization but much lower peak temperature. CO2 is released first and H2 later in the pyrolysis process for all biomass feedstocks, whileas the peak of CO formation follows CO2 formation trend for most feedstocks used, except for peat and pine bark which give a peak later at high temperature. This indicates secondary reactions of tar cracking, steam reforming and char gasification.

  • 118.
    Henshaw Osong, Sinke
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Dahlström, Christina
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Forsberg, Sven
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Andres, Britta
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Sven
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Olin, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Engström, Ann-Christine
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Development of CTMP-based nanofibrillated Cellulose /nanographite composites for paper applications2015Konferensbidrag (Övrigt vetenskapligt)
  • 119.
    Henshaw Osong, Sinke
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Sven
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Pettersson, Gunilla
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    The use of cationic starch and microfibrillated cellulose to improve strength properties of CTMP-based paperboardManuskript (preprint) (Övrigt vetenskapligt)
  • 120.
    Hill, Jan
    et al.
    QualTech AB.
    Karlström, A.
    CTH.
    Ferritsius, Rita
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. StoraEnso.
    Ferritsius, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Pulp property development – inside the gap perspective2015Konferensbidrag (Refereegranskat)
  • 121.
    Hossain, Shakhawath
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bergström, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Sarangi, S.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Computational Design of Fibre Network by Discrete Element Method2017Ingår i: Advancedin Pulp and Paper Research, Proceedings of the 16th Fundamental Research Symposium (Peer-reviewed), Oxford, UK, September 3rd-8th,2017, 2017Konferensbidrag (Refereegranskat)
  • 122.
    Hossain, Shakhawath
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bergström, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    A Particle-based Model to Investigate the Mechanics of Soft Fibre Network2016Konferensbidrag (Refereegranskat)
  • 123.
    Hossain, Shakhawath
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bergström, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Non-Affine Deformation Of Soft Fibre Network2017Konferensbidrag (Refereegranskat)
  • 124.
    Hossain, Shakhawath
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Bergström, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Uesaka, Tetsu
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Nonlinear Compression of Soft Fibre Network2017Ingår i: Book Of Abstracts Deformation And Damage Mechanisms Of Woodfibre Network- Materials And Structures, 2017Konferensbidrag (Refereegranskat)
  • 125.
    Hu, Junhao
    et al.
    Huazhong Univ Sci & Technol, Peoples R China.
    Shao, Jingai
    Huazhong Univ Sci & Technol, Peoples R China.
    Yang, Haiping
    Huazhong Univ Sci & Technol, Peoples R China.
    Lin, Guiying
    Huazhong Univ Sci & Technol, Peoples R China.
    Chen, Yingquan
    Huazhong Univ Sci & Technol, Peoples R China.
    Wang, Xianhua
    Huazhong Univ Sci & Technol, Peoples R China.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Chen, Hanping
    Huazhong Univ Sci & Technol, Peoples R China.
    Co-gasification of coal and biomass: Synergy, characterization and reactivity of the residual char2017Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 244, s. 1-7Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The synergy effect between coal and biomass in their co-gasification was studied in a vertical fixed bed reactor, and the physic-chemical structural characteristics and gasification reactivity of the residual char obtained from co-gasification were also investigated. The results shows that, conversion of the residual char and tar into gas is enhanced due to the synergy effect between coal and biomass. The physical structure of residual char shows more pore on coal char when more biomass is added in the co-gasification. The migration of inorganic elements between coal and biomass was found, the formation and competitive role of K2SiO3, KAlSiO4, and Ca3Al2(SiO4)(3) is a mechanism behind the synergy. The graphization degree is enhanced but size of graphite crystallite in the residual char decreases with biomass blending ratio increasing. TGA results strongly suggest the big difference in the reactivity of chars derived from coal and biomass in spite of influence from co-gasification.

  • 126.
    Hyll, K.
    et al.
    Innventia AB, Drottning Kristinas väg 61, Stockholm, Sweden.
    Björk, Elisabeth
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Innventia AB, Drottning Kristinas väg 61, Stockholm, Sweden.
    Vomhoff, H.
    Innventia AB, Drottning Kristinas väg 61, Stockholm, Sweden.
    Flow imaging characterisation of morphological changes of chemical pulp due to refining2016Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, nr 3, s. 411-421Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The influence of the refining process on the morphological changes of a chemical softwood pulp was investigated. The Voith LR40 industrial-like laboratory low consistency refiner was used, where the pulp was refined with five refining segments with differences in bar widths, groove widths, and cutting angles. The refined pulp was characterized with a fibre analyser with a spatial resolution of approximately 4 μm/pixel and a wide size range. The fines fraction of the refined pulp was also characterized with an imaging flow cytometer with a spatial resolution of 0.33 μm/pixel and a narrower size range. The fibre analyser measurements showed that the mean length, width, and aspect ratio of the fines decreased monotonically with accumulated refining energy. The imaging flow cytometer with its higher spatial resolution showed little change in fines morphology with accumulated refining energy. The morphology of the fines was more dependent on the applied specific refining energy than the design of the refining segment. However, a segment with much finer grooves and bars, initially designed for hardwood, gave significantly less fibre shortening, fines generation, external fibrillation, kink, and fines that were more fibrillar, compared to the other segments.Grant: The authors of this work would like to thank Prof. Lars Mattsson, Thomas Grahn, and Eva Ålander for fruitful discussions. The discussions with Lorentzen & Wettre were of great assistance. The financial support of the Swedish Energy Agency and the Önnesjöstiftelsen to the PhD project, and of the Fibre and Stock Design research programme to this evaluation study is gratefully acknowledged.

  • 127.
    Höglund, Hans
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Pettersson, Gunilla
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Sven
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    A paper or paperboard product comprising at least one ply containing high yield pulp and its production method2018Patent (Övrig (populärvetenskap, debatt, mm))
  • 128.
    Ibrahem, Ismail
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Iqbal, Muhammad Naeem
    Stockholm University.
    Verho, Oscar
    Stockholm University.
    Eivazihollagh, Alireza
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Olsén, Peter
    Stockholm University.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Tai, Cheuk-Wai
    Stockholm University.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Johnston, Eric V.
    Sigrid Therapeutics, Universitetsvägen 8 (Villa Bellona), Stockholm.
    Copper Nanoparticles on Controlled Pore Glass and TEMPO for the Aerobic Oxidation of Alcohols2018Ingår i: ChemNanoMat, ISSN 2199-692X, Vol. 4, nr 1, s. 71-75Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Herein, we report on the facile synthesis of a heterogeneous copper nanocatalyst and its combination with 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) for the aerobic oxidation of alcohols to their corresponding carbonyl compounds. This low cost copper nanocatalyst was found to exhibit excellent recyclability, making it a highly attractive catalytic system from an economical and environmental point of view. Extensive characterization of the catalyst by a number of techniques revealed that it was comprised of well-dispersed Cu(I/II) nanoparticles with an average size of around 6nm.

  • 129.
    Ibrahem, Ismail
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Ma, Guangning
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Afewerki, Samson
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Córdova, Armando
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Palladium/Chiral Amine Co-catalyzed Enantioselective beta-Arylation of alpha,beta-Unsaturated Aldehydes2013Ingår i: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 52, nr 3, s. 878-882Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Palladium and a simple chiral amine are used as co-catalysts for the enantioselective conjugate addition of aryl boronic acids to α,β-unsaturated aldehydes (see scheme). The synthetic utility of this co-catalyzed reaction was demonstrated in the short total syntheses of (R)-(-)-curcumene and 4-aryl-2-ones. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • 130.
    Jiang, X.
    et al.
    School of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China.
    Song, X.
    School of Forestry, Central South University of Forestry and Technology, Changsha 410004, China.
    Chen, Y.
    School of Forestry, Central South University of Forestry and Technology, Changsha 410004, China.
    Zhang, Wennan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Research on biogas production potential of aquatic plants2014Ingår i: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 69, s. 97-102Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper is to explore the biogas production potential of wetland aquatic biomass plants. 7 species of wetland aquatic biomass plants are used in the study, which include 4 plants with more fiber carbohydrate, Acorus calamus Linn, Typha orientalis Presl, Pontederia cordata and Canna indica, and 3 plants with more starch carbohydrate, Colocasia tonoimo Nakai, Thalia dealbata and Hydrocotyle vulgaris. In the experiment, these plants were treated by anaerobic fermentation in batch mode at 37°C. The results show that the anaerobic biogas production potential (ABP, mL·g-1VS) of aquatic biomass plants is different for different components content (%TS). The correlation between ABP and hemicellulose content is significant and negative (R=-0.784, 0.01<p<0.05), and the correlation between ABP and starch carbohydrate content is significant and positive (R=0.767, 0.01<p<0.05). The multiple stepwise regression equation with cross variable can roughly meet the statistical model to reflect the coeffect of hemicellulose, cellulose, starch carbohydrate and lignin on ABP of aquatic biomass plants, y=238.62+2.60x1+28.55x2-2.08x2x3+12.67x3, (Adj-R2=0.962, p(intercept)=0.034, p(x1)=0.101, p(x2)=0.036, p(x2x3)=0.066, p(x3)=0.031, p=0.025, SD=9.95), y represents ABP (mLg-1VS), x1, x2 and x3 represents the cellulose, lignin and starch carbohydrate content (%TS) respectively.

  • 131.
    Johansson, O.
    et al.
    InovoCell, Inc., Brookfield, United States.
    Fernando, D.
    SLU, Uppsala.
    Fenitsius, R.
    Stora Enso AB, Borlänge.
    Daniel, G.
    SLU, Uppsala.
    Ferritsius, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Advancements in optical analysis yields new insight to mechanical pulping processes in an efficient and inexpensive way2016Ingår i: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, s. 267-276Konferensbidrag (Refereegranskat)
    Abstract [en]

    Operating costs, pulp quality, and loss of markets continue to dominate the concern of mechanical pulp producers. The search for process improvements, new products, and cost reductions requires significant amount of pulp testing to find out how improvements or new products can be achieved. Unfortunately, the required testing comes at a significant cost due to the time consuming and labor intensive preparation of each sample. For example, a detailed analysis which requires fractionation, hot disintegration, hand sheets, etc. may cost in excess of a thousand dollars. Thus, for an in-depth study where one compares different processes or operating conditions, the cost is significant. At the IMPC conference in Helsinki 2010, 2014 Fernando & Daniel showed how a modern variation of Simon staining can be used to gain information about the fiber wall conditions. This idea has now been expanded further by combining traditional fiber morphology measurements with the information gained from the measurement of color and intensities. In this paper, we will demonstrate a new approach to evaluate mechanical pulps using a special optical analyzer with the ability to process images in color or image intensities. The additional information gained from the color of the images is discussed. For the study, we have been comparing results from three modem commercial installations. The results from these trials are discussed using traditional testing methods in an earlier paper by Ferritsius et al., (2016). We will continue the discussion and show how these pulp samples were analyzed with a new optical device involving minimal sample preparations.

  • 132.
    Kadej, Marcin
    et al.
    University of Wrocław, Poland.
    Zając, Krzysztof
    University of Wrocław, Poland.
    Ruta, Rafał
    University of Wrocław, Poland.
    Gutowski, Jerzy M.
    Forest Research Institute, Poland .
    Tarnawski, Dariusz
    University of Wrocław, Poland.
    Smolis, Adrian
    University of Wrocław, Poland.
    Olbrycht, Tomasz
    University of Rzeszów, Poland.
    Malkiewicz, Adam
    University of Wrocław, Poland.
    Myśków, Ewelina
    University of Wrocław, Poland.
    Larsson, Mattias C.
    Swedish Univ Agr Sci, Dept Plant Protect Biol, S-23053 Alnarp, Sweden.
    Andersson, Fredrik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Sex pheromones as a tool to overcome the Wallacean shortfall in conservation biology: a case of Elater ferrugineus Linnaeus, 1758 (Coleoptera: Elateridae)2015Ingår i: Journal of Insect Conservation, ISSN 1366-638X, E-ISSN 1572-9753, Vol. 19, nr 1, s. 25-32Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The “Wallacean shortfall”—lack of distributional information—is one of the main problems when trying to assess the threats to and planning conservation strategies for many invertebrate species. Based on published and unpublished records since 1840, as well as on our own field survey, we attempted to estimate if and to what extent the use of pheromone traps increased the detectability of a rare, saproxylic click beetle Elater ferrugineus. The significant increase in the number of records in 2011–2013 shows that the pheromone method made it much easier to detect the occurrence of the species. Advantages of the pheromone method are that it does not disturb the habitat, can be used by non-specialists, is less costly and less time-consuming, and thus providing a useful tool for conservation research (studying biology, ecology and genetics of local populations).

  • 133.
    Karlsson, Anette
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Improved hydrogene peroxide bleaching of mechanical pulps through fundamental understanding of the influence of heat, iron, fines and chemical treatment on chromophore content2013Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
  • 134.
    Karlsson, Anette
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Paulsson, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Reduced heat-induced darkening and enhanced bleachability of mechanical pulps studied using the UV-visible absorption spectraManuskript (preprint) (Övrigt vetenskapligt)
  • 135.
    Karlsson, Anette
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. SCA R and D Centre AB, SE-851 21 Sundsvall, Sweden.
    Paulsson, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. AkzoNobel Pulp and Performance Chemicals, SE-445 80 Bohus, Sweden.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Strategies to reduce heat-induced darkening for enhanced bleachability of mechanical pulps2014Ingår i: Appita journal, ISSN 1038-6807, Vol. 67, nr 1, s. 50-57Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Under mechanical pulping conditions, elevated temperature initiates reactions in the wood constituents resulting in the formation of coloured structures. In an attempt to reduce the formation of colour, a number of additives have been examined to assess their ability to inhibit heat-induced darkening of a Norway spruce (Picea abies) stone groundwood (SGW) pulp. SGW pulp was used as a model pulp with the purpose of imitating a thermomechanical pulp (IMP). The heat-treated SGW pulp, both with and without additives present, was subsequently bleached with 4.5% hydrogen peroxide at high pulp consistency and with varying alkali charges in order to examine the hydrogen peroxide bleachability of such pulps. Heat treatment at 170 °C resulted in a loss of brightness of about 4% ISO after heating for 60 seconds. The reduction in brightness could only partly be regained through high consistency hydrogen peroxide bleaching; the SGW pulp displayed a brightness of 83.7% ISO whereas the heat-treated SGW pulp reached a brightness of 80.4% ISO. Heat treatment with a low addition rate (1 %) of alkaline hydrogen peroxide, sodium bisulfite or sodium sulfite, with a subsequent hydrogen peroxide bleaching stage, resulted in an improved bleached brightness of about 81.6% ISO, i.e. the loss of brightness due to heat was still approximately 2% ISO. Sodium borohydride (1 %) did not suppress the thermal darkening but improved the bleached brightness by approximately 2% ISO compared to the heat-treated SGW pulp and resulted in a brightness of 82.6% ISO. Addition of a chelating agent (DTPA, 0.11 and 0.45%) and the radical scavengers phthalic hydrazide (1 %) and 1 -hexanol (1 %) suppressed the heat-induced darkening somewhat but did not improve the hydrogen peroxide bleachability to any noticeable extent. Addition of citric acid (0.6%) did not suppress the thermal darkening and resulted in impaired bleachability.

  • 136.
    Karlström, A.
    et al.
    Chalmers University of Technology, Göteborg.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Refining efficiency for future CTIVIP and TMP systems co-optimizing fundamental wood material knowledge with a soft sensor control approach2016Ingår i: International Mechanical Pulping Conference 2016, IMPC 2016, TAPPI Press, 2016, s. 304-316Konferensbidrag (Refereegranskat)
    Abstract [en]

    Internal variables in (C)TMP-refining processes (e.g. temperature, consistency, fiber residence time, backward flowing steam and forces acting upon the chips and pulp) are defined as physical states obtained in different parts of the refining zones. In short, they differ from the traditional external variables (e.g. dilution water feed rate, load and gap distance) which are not available as distributed variables from refining zone measurements. The internal variables are the backbone of physical models and such models can be used for on-line implementation of soft sensors and advanced process control. Of special interest are the temperature and consistency profiles together with fiber residence time, which are the internal variables in focus of (in) this study. Moreover, they are directly linked to pulp and handsheet property development. To illustrate the capability to use a modeling strategy, two examples are given; one where it is shown how to reach a 40% reduction in specific energy in a CD82-refiner using a new control strategy without violating the pulp properties studied and one example where the consistency can be controlled individually in two parallel Twin refining zones. Hence, the article comprises both temperature and consistency control to reach optimal process conditions.We believe that increased fundamental understanding of the role of the spatially dependent viscosity in refining in general will be a key factor to find ways to further improve energy efficiency of refining.

  • 137.
    Karlström, A.
    et al.
    Chalmers University of Technology, Göteborg, Sweden .
    Hill, J.
    QualTech AB, Tyringe, Sweden.
    Ferritsius, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Ferritsius, Rita
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Stora Enso Kvarnsveden, Borlänge, Sweden.
    Engstrand, Per
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Can we increase the proportion of electrical energy into fibre development in existing HC-refiners?2014Ingår i: International Mechanical Pulping Conference, IMPC 2014, Paper Engineers' Association (PI) , 2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Currently some 5 % of the electrical energy input in high consistency refining can be attributed to fibre development work. The rest is related to thermo- dynatnical steam generation. Can this unfavourable relation between fibre development and heat generation eventually be improved? A pre-requisite to consistent improvement is a stable process, controlled to targets deduced from profound process evaluations. This statement is elaborated based on two case studies and extensive refiner modelling. It is indicated that a well designed process including its basic process control can with proper refiner control reach energy reductions in excess of 20 %. Proper selections of process targets aligned with choice of segments can further increase the energy reduction in existing lines. These drastic energy reductions will demand concurrent observations and process modelling based on spatial measurements in the refining zone rather than slow, inadequate feedback control from pulp property measurements downstream. This will furthermore stress the need for more advanced control schemes if the full potential is to be captured. Additionally this approach will be a key element in the development of novel process approaches with even larger potential of energy reduction.

  • 138.
    Karlström, Anders
    et al.
    Chalmers University of Technology, Göteborg.
    Hill, Jan
    QualTech AB, Tyringe.
    Ferritsius, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Ferritsius, Rita
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Pulp property development Part III: Fiber residence time and consistency profile impact on specific energy and pulp properties2016Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, nr 2, s. 300-307Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper focuses on the pulp properties obtained from ThermoMechanical Pulp (TMP) CD refiners. Undersampled pulp variables are expanded into an oversampled set of process data, which makes it possible to analyze pulp properties in a dynamic time frame. It is shown that, in order to gain deeper insight into the defibration/fibrillation at a specific energy input, one needs to know the fiber residence time and the consistency profile. Moreover, the fiber residence time in the flat zone (FZ) and conical zone (CD) are intertwined with the consistency out from FZ and CD. Together with an external variable (production), these internal variables are essential for predicting the pulp properties. It is also shown that internal process conditions from different test series can be manipulated in the operating window using a low-frequency gain description obtained from an ARX model. The same mapping procedure can be applied to pulp and handsheet properties (in this paper represented by the tensile index), and this opens for implementation of new optimization routines to find more energy efficient operating points while maintaining prespecified pulp quality.

  • 139.
    Karlström, Anders
    et al.
    Chalmers University of Technology, Göteborg, Sweden.
    Hill, Jan
    QualTech AB, Tyringe, Sweden.
    Ferritsius, Rita
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Ferritsius, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Pulp property development Part I: Interlacing under-sampled pulp properties and TMP process data using piece-wise linear functions2015Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 30, nr 4, s. 599-608Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Thermo-Mechanical Pulp (TMP) refiners served in this work as an example of how to combine oversampled and undersampled variables on a common timeframe for further analysis.To get more information from the refining process, temperature measurement arrays in the refining zones were studied alongside process measurements such as motor load, production rates, plate gaps, dilution waters, pulp properties and manually measured blow-line consistency.The undersampled data set consisted of 63 laboratory samples obtained at a Swedish TMP mill, which were tested for tensile index, mean fiber length and Somerville shives content. The pulp samples were obtained at five different periods during three months to cover a large dynamic operating window.The data set was expanded using a piece-wise linear approach. The measurements inside the refining zone were shown to be important variables when interlacing the undersampled pulp properties with the oversampled process data set, consisting of 350 000 samples.Use of an extended entropy model provided a palette of information about the process conditions inside the refining zone. Particularly, the residence time and the consistency in the refining zones were essential for the pulp property development, as a link between the refining segment pattern used and the current state of refiner operation.

  • 140.
    Karlström, Anders
    et al.
    Chalmers University of Technology, Göteborg.
    Hill, Jan
    QualTech AB, Tyringe.
    Ferritsius, Rita
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Ferritsius, Olof
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Pulp property development Part II: Process non-linearities and their influence on pulp property development2016Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 31, nr 2, s. 287-299Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is shown in this paper that knowledge of the spatially measured temperatures inside the refining zone in TMP refiners is essential in describing non-linear dynamics of high consistency refining. By expanding the pulp and handsheet properties using piece-wise linear functions into the time domain, an auto-regressive model can be applied to verify that the tempera-ture and the consistency profiles, in combination with the motor load and production rate, are key input candidates when modeling changes in different pulp properties. The model accuracy is analyzed using process information captured at different time and operating conditions. It is also shown that it is more complex to estimate and validate the tensile index than the mean fiber length and Somerville shives content, especially close to refiner operating limits where a shift in the process gain may occur. This type of switched dynamics in tensile index estimation at a specific consistency is related to non-linear behaviors where the fiber pad distribution most likely undergoes a local collapse.

  • 141.
    Kumar, V.
    et al.
    Åbo Akad Univ, Turku, Finland.
    Forsberg, S.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Engström, A.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Nurmi, M.
    Åbo Akad Univ, Turku, Finland.
    Dahlström, Christina
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Toivakka, Martti
    Åbo Akad Univ, Turku, Finland.
    Conductive carbon-nanocellulose coatings on paper2017Ingår i: TAPPI Journal, ISSN 0734-1415, Vol. 16, nr 6, s. 310-311Artikel i tidskrift (Övrigt vetenskapligt)
  • 142.
    Kumar, V.
    et al.
    Åbo Akademi University, Turku, Finland.
    Forsberg, Sven
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Engström, Ann-Christine
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Nurmi, M.
    Åbo Akademi University, Turku, Finland.
    Dahlström, Christina
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Toivakka, M.
    Åbo Akademi University, Turku, Finland.
    Conductive carbon-nanocellulose coatings on paper2017Ingår i: Paper Conference and Trade Show, PaperCon 2017: Renew, Rethink, Redefine the Future, TAPPI Press , 2017, s. 26-35Konferensbidrag (Refereegranskat)
  • 143.
    Kumar, Vinay
    et al.
    Åbo Akad Univ, Turku, Finland.
    Forsberg, Sven
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Engström, Ann-Christine
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Nurmi, Maristiina
    Åbo Akad Univ, Turku, Finland.
    Andres, Britta
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Dahlström, Christina
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Toivakka, Martti
    Åbo Akad Univ, Turku, Finland.
    Conductive nanographite-nanocellulose coatings on paper2017Ingår i: Flexible And Printed Electronics, ISSN 2058-8585, Vol. 2, nr 3, artikel-id aa728eArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    Paper products with active and functional coatings have attracted interest in recent years to counter the stagnating demand for traditional graphic paper grades. Conductive coatings have potential uses in various energy generation and storage applications, e.g. in batteries, supercapacitors, and photovoltaics. The current work aims to demonstrate large-scale production of flexible low-cost nanographite coatings on paper-based substrate. The large aspect ratio of graphene present in the suspension limits solids content to very low values, which makes it challenging to create thick coating layers required for high conductivity. The use of nanocellulose binder together with a custom-built slot-coating device enables roll-to-roll coating of thick conductive coatings on paper. The rheological and water-retention properties of nanographite-nanocellulose suspensions are reported. The influence of coat weight, carbon black addition, and calendering on coating structure and the resulting conductivity of the coatings is investigated. Impact of humidity and bending/creasing of coated samples on their electrical performance is explored as well. The lowest surface resistances obtained were in the range 1-2 Ohm/square, for 15 g m(-2) coat weight. Increasing the coat weight and calendering nip load resulted in higher conductivity of coatings. Carbon black addition deteriorated the conductivity somewhat, probably due to increased porosity of coatings. Moisture and creasing did not affect significantly the conductivity of high coat weight and calendered samples. The results reported are very encouraging for future research on further improving the electrical performance of such carbon coatings.

  • 144.
    Lebreton, Sebastien
    et al.
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    Borrer-Echeverry, Felipe
    Biological Control Laboratory, Colombian Corporation of Agricultural Research, Las Palmas, Bogota, Colombia.
    Gonzalez, Francisco
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    Solum, Marit
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    Wallin, Erika
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hedenström, Erik
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Hansson, Bill S
    Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany.
    Gustavsson, Anna-Lena
    Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Solna.
    Bengtsson, Marie
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    Birgersson, Göran
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    Walker, William B
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    Dweck, Hany KM
    Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany; Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, USA.
    Becher, Paul G
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    Witzgall, Peter
    Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp.
    A Drosophila female pheromone elicits species-specific long-range attraction via an olfactory channel with dual specificity for sex and food2017Ingår i: BMC Biology, ISSN 1741-7007, E-ISSN 1741-7007, Vol. 15, nr 1, artikel-id 88Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Mate finding and recognition in animals evolves during niche adaptation and involves social signals and habitat cues. Drosophila melanogaster and related species are known to be attracted to fermenting fruit for feeding and egg-laying, which poses the question of whether species-specific fly odours contribute to long-range premating communication. Results: We have discovered an olfactory channel in D. melanogaster with a dual affinity to sex and food odorants. Female flies release a pheromone, (Z)-4-undecenal (Z4-11Al), that elicits flight attraction in both sexes. Its biosynthetic precursor is the cuticular hydrocarbon (Z,Z)-7,11-heptacosadiene (7,11-HD), which is known to afford reproductive isolation between the sibling species D. melanogaster and D. simulans during courtship. Twin olfactory receptors, Or69aB and Or69aA, are tuned to Z4-11Al and food odorants, respectively. They are co-expressed in the same olfactory sensory neurons, and feed into a neural circuit mediating species-specific, long-range communication; however, the close relative D. simulans, which shares food resources with D. melanogaster, does not respond to Z4-11Al. Conclusion: The Or69aA and Or69aB isoforms have adopted dual olfactory traits. The underlying gene yields a collaboration between natural and sexual selection, which has the potential to drive speciation.

  • 145.
    Lidenmark, Cecilia
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Time induced spreading and adhesion of latex polymers2013Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
  • 146.
    Lidenmark, Cecilia
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    Pettersson, Torbjörn
    KTH Royal Inst Technol, SE-10044 Stockholm, Sweden.
    Karlsson, Ola. J.
    Lund University, Lund, Sweden.
    Notley, Shannon M.
    Australian National University, Canberra, Australia.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för naturvetenskap.
    The adhesive behavior of extracted Latex polymers towards Silicon oxide and Cellulose2013Ingår i: International Journal of Adhesion and Adhesives, ISSN 0143-7496, E-ISSN 1879-0127, Vol. 44, s. 250-258Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objective with this work is to compare the adhesive behavior for latex polymers of different Glass transition Temperatures (Tg) at different length scales and with different contact times. This is accomplished by two techniques: AFM colloidal probe force measurements and JKR-measurements. The aim is to compare the results from these two techniques and relate them to the interaction of the latex polymers towards oxidized silicon wafers and silica/cellulose probes. Theory suggests that altering the short timeframes used in the colloidal probe technique does not affect the ranking of the adhesion for the different polymers, but for the macroscopic JKR-technique it influences the measured work of adhesion. It is therefore important to let the system reach a steady state before assuming complete spreading and adhesion. AFM and JKR measurements showed the same trends where the polymer with lowest content of styrene has the lowest Tg and the highest adhesion, due to the larger polymer chain mobility.

  • 147.
    Lindman, Björn
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Lund Univ, Ctr Chem & Chem Engn, Dept Chem, Div Phys Chem, SE-22100 Lund, Sweden.
    Medronho, Bruno
    Univ Algarve, Fac Sci & Technol, P-8005139 Faro, Portugal..
    The Subtleties of Dissolution and Regeneration of Cellulose: Breaking and Making Hydrogen Bonds2015Ingår i: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 10, nr 3, s. 3811-3814Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Cellulose dissolution and regeneration are old topics that have recently gained renewed attention. This is reflected in both applications - earlier and novel - and in scientific controversies. There is a current discussion in the literature on the balance between hydrogen bonding and hydrophobic interactions in controlling the solution behavior of cellulose. Some of the key ideas are recalled.

  • 148.
    Lindman, Björn
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Lunds Universitet.
    Medronho, Bruno
    University of Algarve, Faro, Portugal.
    Alves, Luís
    University of Coimbra, Portugal.
    Costa, Carolina
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Edlund, Håkan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    Norgren, Magnus
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik.
    The relevance of structural features of cellulose and its interactions to dissolution, regeneration, gelation and plasticization phenomena2017Ingår i: Physical Chemistry, Chemical Physics - PCCP, ISSN 1463-9076, E-ISSN 1463-9084, Vol. 19, nr 35, s. 23704-23718Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cellulose is the most abundant polymer and a very important renewable resource. Since cellulose cannot be shaped by melting, a major route for its use for novel materials, new chemical compounds and renewable energy must go via the solution state. Investigations during several decades have led to the identification of several solvents of notably different character. The mechanisms of dissolution in terms of intermolecular interactions have been discussed from early work but, even on fundamental aspects, conflicting and opposite views appear. In view of this, strategies for developing new solvent systems for various applications have remained obscure. There is for example a strong need for using forest products for higher value materials and for environmental and cost reasons to use water-based solvents. Several new water-based solvents have been developed recently but there is no consensus regarding the underlying mechanisms. Here we wish to address the most important mechanisms described in the literature and confront them with experimental observations. A broadened view is helpful for improving the current picture and thus cellulose derivatives and phenomena such as fiber dissolution, swelling, regeneration, plasticization and dispersion are considered. In addition to the matter of hydrogen bonding versus hydrophobic interactions, the role of ionization as well as some applications of new knowledge gained are highlighted.

  • 149.
    Lindman, Björn
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Univ Coimbra, Dept Chem, P-3004535 Coimbra, Portugal.
    Medronho, Bruno
    Univ Algarve, Fac Sci & Technol MEDITBIO, Campus Gambelas,Ed 8, P-8005139 Faro, Portugal.
    Karlström, Gunnar
    Lund Univ, Div Theoret Chem, Dept Chem, Ctr Chem & Chem Engn, SE-22100 Lund, Sweden.
    Clouding of nonionic surfactants2016Ingår i: Current Opinion in Colloid & Interface Science, ISSN 1359-0294, E-ISSN 1879-0399, Vol. 22, s. 23-29Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Nonionic surfactants have broad applications such as cleaning and dispersion stabilization, which frequently are hampered by strong temperature sensitivities. As manifested by clouding and decreased solubility with increasing temperature, the interaction between water and the oligo(oxyethylene) head-groups is becoming less favorable. Different aspects of surfactant self-assembly, like the critical micelle concentration, micelle size and shape, intermicellar interactions and phase separation phenomena are reviewed as well as suggested underlying causes of the temperature dependence. Furthermore, the effect of cosolutes on clouding and the behavior of related systems, non-aqueous solutions and nonionic polymers, are examined. (C) 2016 Elsevier Ltd. All rights reserved.

  • 150.
    Lindman, Björn
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för kemiteknik. Lund Univ, Ctr Chem & Chem Engn, Dept Chem, Div Phys Chem, SE-22100 Lund, Sweden.
    Medronho, Bruno
    Univ Algarve, Fac Sci & Technol, P-8005139 Faro, Portugal.
    Theliander, Hans
    Chalmers Univ Engn, Forest Prod & Chem Engn, SE-41296 Gothenburg, Sweden.
    Editorial: Cellulose dissolution and regeneration: systems and interactions2015Ingår i: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 30, nr 1, s. 2-3Artikel i tidskrift (Refereegranskat)
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