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  • 1.
    Abitbol, Tiffany
    et al.
    RISE Research Institutes of Sweden. EPFL, Switzerland.
    Kubat, Mikaela
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Brännvall, Elisabet
    RISE Research Institutes of Sweden.
    Kotov, Nikolay
    KTH Royal Institute of Technology, Sweden.
    Johnson, C Magnus
    KTH Royal Institute of Technology, Sweden.
    Nizamov, Rustem
    University of Turku, Finland.
    Nyberg, Mikael
    University of Turku, Finland.
    Miettunen, Kati
    University of Turku, Finland.
    Nordgren, Niklas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Guerreiro, Maria Pita
    RISE Research Institutes of Sweden.
    Isolation of Mixed Compositions of Cellulose Nanocrystals, Microcrystalline Cellulose, and Lignin Nanoparticles from Wood Pulps2023In: ACS Omega, E-ISSN 2470-1343, Vol. 8, no 24, p. 21474-21484Article in journal (Refereed)
    Abstract [en]

    From a circular economy perspective, one-pot strategies for the isolation of cellulose nanomaterials at a high yield and with multifunctional properties are attractive. Here, the effects of lignin content (bleached vs unbleached softwood kraft pulp) and sulfuric acid concentration on the properties of crystalline lignocellulose isolates and their films are explored. Hydrolysis at 58 wt % sulfuric acid resulted in both cellulose nanocrystals (CNCs) and microcrystalline cellulose at a relatively high yield (>55%), whereas hydrolysis at 64 wt % gave CNCs at a lower yield (<20%). CNCs from 58 wt % hydrolysis were more polydisperse and had a higher average aspect ratio (1.5-2×), a lower surface charge (2×), and a higher shear viscosity (100-1000×). Hydrolysis of unbleached pulp additionally yielded spherical nanoparticles (NPs) that were <50 nm in diameter and identified as lignin by nanoscale Fourier transform infrared spectroscopy and IR imaging. Chiral nematic self-organization was observed in films from CNCs isolated at 64 wt % but not from the more heterogeneous CNC qualities produced at 58 wt %. All films degraded to some extent under simulated sunlight trials, but these effects were less pronounced in lignin-NP-containing films, suggesting a protective feature, but the hemicellulose content and CNC crystallinity may be implicated as well. Finally, heterogeneous CNC compositions obtained at a high yield and with improved resource efficiency are suggested for specific nanocellulose uses, for instance, as thickeners or reinforcing fillers, representing a step toward the development of application-tailored CNC grades. © 2023 The Authors. 

  • 2.
    Abitbol, Tiffany
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Mijlkovic, Ana
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Malafronte, Loredana
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Stevanic Srndovic, Jasna
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Larsson, Per Tomas
    RISE Research Institutes of Sweden.
    Lopez-Sanchez, Patricia
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Cellulose nanocrystal/low methoxyl pectin gels produced by internal ionotropic gelation.2021In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 260, article id 117345Article in journal (Refereed)
    Abstract [en]

    The biotechnological applications of cellulose nanocrystals (CNCs) continue to grow due to their sustainable nature, impressive mechanical, rheological, and emulsifying properties, upscaled production capacity, and compatibility with other materials, such as protein and polysaccharides. In this study, hydrogels from CNCs and pectin, a plant cell wall polysaccharide broadly used in food and pharma, were produced by calcium ion-mediated internal ionotropic gelation (IG). In the absence of pectin, a minimum of 4 wt% CNC was needed to produce self-supporting gels by internal IG, whereas the addition of pectin at 0.5 wt% enabled hydrogel formation at CNC contents as low as 0.5 wt%. Experimental data indicate that CNCs and pectin interact to give robust and self-supporting hydrogels at solid contents below 2.5 %. Potential applications of these gels could be as carriers for controlled release, scaffolds for cell growth, or wherever else distinct and porous network morphologies are required.

  • 3.
    Andersson, Jan-Erik
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Nordman, Roger
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Vikberg, Tommy
    Luleå Technical University, Sweden.
    Energy mapping in the sawmill industry with focus on drying kilns2013Conference paper (Other academic)
    Abstract [en]

    The forest industry stands for approximately 11 % of Sweden’s total export. However, the forest industry is energy intensive. In 2008, sawmill industry alone consumed almost 8,7 TWh of energy, corresponding to 5 % of the Swedish industries total energy consumption. Out of their total consumption, 2200 GWh was electric power, 194 GWh heating oil , 4229 GWh bio-fuel, 574 GWh district heating, and other fuels such as diesel 1503 GWh [1].The project ”EESI- Energy Efficiency in the Sawmill Industry” was started in the spring of 2010 with the aim of demonstrating the possibilities to reduce the energy consumption in the sawmill industry with 20 % by 2020. 16 sawmill corporations and 14 equipment suppliers has joined the project which is carried out in two phases of which the first phase was carried out during 2010 and 2011. EESI has now reached half time and the first energy-saving implementations have been completed at the participating sawmills.This paper presents the energy-mapping, measurements and modelling performed by the participating sawmills during the first phase of the project [2, 3]. The average energy consumption per sawn cubic metre of boards varied between approximately 300 to 500 kWh/m3. Out of this, the electricity consumption was on average 85 kWh/m3, bio-fuel 290 kWh/m3 and diesel 1.8 l/m3.However, the main concern from sawmills regarding energy consumption was the wood drying process. The striking results from the preliminary measurements were the large variation in energy consumption even with similar drying kilns. This was especially apparent for the heat consumption in kiln dryers which could vary as much as 50 % for the same dimension of spruce planks.The results from the first phase of the project resulted in a large number of actions in order to reduce the energy consumption which are now being implemented or have already been completed. Examples of those actions are: simplified management system adapted to sawmills, weighing of packages for more accurate wood drying, reduced speed or intermittent operation of the air circulating fans in batch kilns and moisture content measurements of bio-fuel.References[1] Statistiska centralbyrån (SCB), 2013, Industrins årliga energianvändning 2011, Slutliga uppgifter, EN23SM1301, ISSN 1654-367X. (In Swedish). [2] Andersson, J-E., Lycken, A., Nordman, R., Olsson, M., Räftegård, O., and Wamming, T. State of the art – Energianvändning i den svenska sågverksindustrin. SP Rapport 2011:42, ISBN 978-91-86622-72-5. (In Swedish).[3] Andersson, J-E., Räftegård, O., Lycken, A., Olsson, M., Wamming, T., and Nordman, R. Sammanställning av energimätningar från EESI fas 1. SP Rapport 2011:41, ISBN 978-91-86622-71-8. (In Swedish).

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  • 4.
    Aranzana-Climent, Vincent
    et al.
    Uppsala University, Sweden.
    Hughes, Diarmaid
    Uppsala University, Sweden.
    Cao, Sha
    Uppsala University, Sweden.
    Tomczak, Magdalena
    National Medicines Institute, Poland.
    Urbas, Malgorzata
    National Medicines Institute, Poland.
    Zabicka, Dorota
    Uppsala University, Sweden.
    Vingsbo Lundberg, Carina
    Statens Serum Institut, Denmark.
    Hansen, Jon
    Statens Serum Institut, Denmark.
    Lindberg, Johan
    RISE Research Institutes of Sweden, Bioeconomy and Health, Chemical and Pharmaceutical Toxicology.
    Hobbie, Sven N
    University of Zurich, Switzerland.
    Friberg, Lena E
    Uppsala University, Sweden.
    Translational in vitro and in vivo PKPD modelling for apramycin against Gram-negative lung pathogens to facilitate prediction of human efficacious dose in pneumonia2022In: Clinical Microbiology and Infection, ISSN 1198-743X, E-ISSN 1469-0691, Vol. 28, no 10, p. 1367-1374Article in journal (Refereed)
    Abstract [en]

    Objectives: New drugs and methods to efficiently fight carbapenem-resistant gram-negative pathogens are sorely needed. In this study, we characterized the preclinical pharmacokinetics (PK) and pharmacodynamics of the clinical stage drug candidate apramycin in time kill and mouse lung infection models. Based on in vitro and in vivo data, we developed a mathematical model to predict human efficacy. Methods: Three pneumonia-inducing gram-negative species Acinetobacter baumannii, Pseudomonas aeruginosa, and Klebsiella pneumoniae were studied. Bactericidal kinetics were evaluated with time-kill curves; in vivo PK were studied in healthy and infected mice, with sampling in plasma and epithelial lining fluid after subcutaneous administration; in vivo efficacy was measured in a neutropenic mouse pneumonia model. A pharmacokinetic-pharmacodynamic model, integrating all the data, was developed and simulations were performed. Results: Good lung penetration of apramycin in epithelial lining fluid (ELF) was shown (area under the curve (AUC)ELF/AUCplasma = 88%). Plasma clearance was 48% lower in lung infected mice compared to healthy mice. For two out of five strains studied, a delay in growth (∼5 h) was observed in vivo but not in vitro. The mathematical model enabled integration of lung PK to drive mouse PK and pharmacodynamics. Simulations predicted that 30 mg/kg of apramycin once daily would result in bacteriostasis in patients. Discussion: Apramycin is a candidate for treatment of carbapenem-resistant gram-negative pneumonia as demonstrated in an integrated modeling framework for three bacterial species. We show that mathematical modelling is a useful tool for simultaneous inclusion of multiple data sources, notably plasma and lung in vivo PK and simulation of expected scenarios in a clinical setting, notably lung infections. © 2022 The Author(s)

  • 5.
    Arrhenius, Karine
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Applied Mechanics.
    Culleton, Lucy
    NPL National Physical Laboratory, UK.
    Nwaboh, Javis
    PTB Physikalisch-Technische Bundesanstalt, Germany.
    Li, Jianrong
    VSL Van Swinden Laboratorium B.V., Netherlands.
    Need for a protocol for performance evaluation of the gas analyzers used in biomethane conformity assessment2023In: Accreditation and Quality Assurance, ISSN 0949-1775, E-ISSN 1432-0517Article in journal (Refereed)
    Abstract [en]

    Biomethane may contain trace components that can have adverse effects on gas vehicles performances and on the pipelines when injected in the gas grid. Biomethane quality assurance against specifications is therefore crucial for the integrity of the end-users’ appliances. Analytical methods used to assess biomethane conformity assessment must be validated properly and possibly, new methods specifically for biomethane should be developed. This paper provides an overview of the biomethane quality assurance infrastructure and the challenges faced with focus on sampling, analysis methods, reference gas mixtures, and performance evaluation. Currently, requirements for analytical method validation and fit-for-purpose assessments do not exist for biomethane. The industry is in urgent need of a protocol to evaluate the fit-for-purpose of methods in a harmonized manner. Reference gas mixtures to check the accuracy of the instrument and to determine the traceability of the measurement are also urgently required. 

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  • 6.
    Arya, Mina
    et al.
    University of Borås, Sweden.
    Malmek, Else-Marie
    Juteborg AB, Sweden.
    Ecoist, Thomas Koch
    Ecoist AB, Sweden.
    Pettersson, Jocke
    RISE Research Institutes of Sweden, Materials and Production, Polymeric Materials and Composites.
    Skrifvars, Mikael
    University of Borås, Sweden.
    Khalili, Pooria
    University of Borås, Sweden.
    Enhancing Sustainability: Jute Fiber-Reinforced Bio-Based Sandwich Composites for Use in Battery Boxes2023In: Polymers, E-ISSN 2073-4360, Vol. 15, no 18, article id 3842Article in journal (Refereed)
    Abstract [en]

    The rising industrial demand for environmentally friendly and sustainable materials has shifted the attention from synthetic to natural fibers. Natural fibers provide advantages like affordability, lightweight nature, and renewability. Jute fibers’ substantial production potential and cost-efficiency have propelled current research in this field. In this study, the mechanical behavior (tensile, flexural, and interlaminar shear properties) of plasma-treated jute composite laminates and the flexural behavior of jute fabric-reinforced sandwich composites were investigated. Non-woven mat fiber (MFC), jute fiber (JFC), dried jute fiber (DJFC), and plasma-treated jute fiber (TJFC) composite laminates, as well as sandwich composites consisting of jute fabric bio-based unsaturated polyester (UPE) composite as facing material and polyethylene terephthalate (PET70 and PET100) and polyvinyl chloride (PVC) as core materials were fabricated to compare their functional properties. Plasma treatment of jute composite laminate had a positive effect on some of the mechanical properties, which led to an improvement in Young’s modulus (7.17 GPa) and tensile strength (53.61 MPa) of 14% and 8.5%, respectively, as well as, in flexural strength (93.71 MPa) and flexural modulus (5.20 GPa) of 24% and 35%, respectively, compared to those of JFC. In addition, the results demonstrated that the flexural properties of jute sandwich composites can be significantly enhanced by incorporating PET100 foams as core materials. © 2023 by the authors.

  • 7.
    Aulin, Christian
    et al.
    RISE Research Institutes of Sweden.
    Flodberg, Göran
    RISE Research Institutes of Sweden.
    Ström, Göran
    RISE Research Institutes of Sweden.
    Lindström, Tom S. C.
    RISE Research Institutes of Sweden.
    Enhanced mechanical and gas barrier performance of plasticized cellulose nanofibril films2022In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 37, no 1, p. 138-148Article in journal (Refereed)
    Abstract [en]

    Cellulose nanofibrils (CNF) are mixed with plasticizers; sorbitol and glycerol, through high-pressure homogenization to prepare multifunctional biohybrid films. The resulting plasticized films obtained after solvent evaporation are strong, flexible and demonstrate superior toughness and optical transparency. The oxygen barrier properties of the biohybrid films outperform commercial packaging materials. The sorbitol-plasticized CNF films possess excellent oxygen barrier properties, 0.34 cm3·μm/m2·day·kPa at 50 % relative humidity, while significantly enhancing the toughness and fracture strength of the films. CNF films plasticized by 20 wt.% of sorbitol and glycerol could before rupture, be strained to about 9 % and 12 %, respectively. The toughness of the plasticized films increased by ca. 300 % compared to the pristine CNF film. Furthermore, the water vapor barrier properties of the biohybrid films were also preserved by the addition of sorbitol. CNF films plasticized with sorbitol was demonstrated to simultaneously enhance fracture toughness, work of fracture, softening behavior while preserving gas barrier properties. Highly favorable thermomechanical characteristics were found with CNF/sorbitol combinations and motivate further work on this material system, for instance as a thermoformable matrix in biocomposite materials. The unique combination of excellent oxygen barrier behavior, formability and optical transparency suggest the potential of these CNF-based films as an alternative in flexible packaging of oxygen sensitive devices like thin-film transistors or organic light-emitting diode displays, gas storage applications and as barrier coatings/laminations in packaging applications, including free-standing films as aluminium-replacement in liquid board and primary packaging, as replacement for polyethylene (PE) in wrapping paper, e. g. sweats and confectionary.

  • 8.
    Bakratsas, Georgios
    et al.
    University of Ioannina, Greece.
    Polydera, Angeliki
    University of Ioannina, Greece.
    Nilson, Oskar
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Kossatz, Lalie
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Xiros, Charilaos
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Katapodis, Petros
    University of Ioannina, Greece.
    Stamatis, Haralambos
    University of Ioannina, Greece.
    Single-cell protein production by Pleurotus ostreatus in submerged fermentation†2023In: Sustainable Food Technology, ISSN 2753-8095, Vol. 1, no 3, p. 377-389Article in journal (Refereed)
    Abstract [en]

    Agricultural land shrinkage, decreasing global water resources, population increase and malnutrition highlight the need for new food sources. Single-cell protein derived from microorganisms could be a solution to high protein demand. The aim of this work was to optimize the cultivation conditions for single-cell protein production by Pleurotus ostreatus LGAM 1123 in submerged cultures and valorize fiber sludge, a low cost industrial side stream from the pulp and paper industry, as a substrate for single-cell protein (SCP) production. A study on the effect of different cultivation conditions on fungal growth and protein production has been conducted. Response surface methodology was used to investigate the combined effect of the most important factors (glucose and yeast extract medium concentrations) and optimize the process. A maximum protein production of 10.0 ± 0.9 g L-1 was found for the submerged cultivation of the fungus in a 3.5 L stirred-tank bioreactor, while the biomass produced and its total protein content were 26.0 ± 2.0 g L-1 and 44.8 ± 0.8%, respectively. As an industrial application, a cellulosic hydrolysate obtained after enzymatic hydrolysis of fibre sludge in the optimized medium composition was used. Fibre sludge was shown to be an excellent feedstock for SCP production achieving productivity and protein content very similar to glucose fermentations. Single-cell protein of P. ostreatus presented higher amino acid scores compared to the recommended ones for valine, leucine, and aromatic amino acids in human nutrition. Therefore, P. ostreatus biomass could stand as an alternative vegan protein source due to its high protein content and amino acid composition. 

  • 9.
    Bergentall, Martina
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Solid-state fermentation of side streams from Saccharina latissima2023Report (Other academic)
    Abstract [en]

    The cultivation of brown macroalgae, such as Laminaria ssp. and Saccharina latissima, has increased extensively during the last decades; according to a report by Food and Agriculture Organisation of the United Nations1 , the cultivation of brown seaweeds exceeded 16 M tons worldwide as per 2019. At the Swedish West coast, the most cultivated brown alga is S. latissima – Sugar kelp – and it is mainly produced for food purposes. The S. latissima body consists of a blade, a stipe and a holdfast. The holdfast and stipe are stiff and tough and not useful for food in its raw state; instead, they become a side stream in the production. Fermentation of the stipes and holdfasts could be a way of improving their food properties, but the traditionally used and food-safe microorganisms employed for fermentation of soybeans, cereals, and other plant-based substrates are adapted to grow on plant carbohydrates such as starch and cellulose. This could be an obstacle when attempting to use algae as a substrate, since they are mainly constituted of other carbohydrates, such as alginate, laminarin, fucoidan and mannitol. For fungi to grow on algal biomass there should be a need for enzymes that can degrade the algal carbohydrates to release sugar units to be taken up by the fungal cells, but we did not find any reports on known food-safe fungi specialized on algae. Therefore, we wanted to test different pre-treatments, with the aim to make the algal carbohydrates accessible for established and safe fungi, traditionally used for fermentation of plant material, so that they would be able to ferment the algal biomass. Our project aimed at assessing the feasibility of using side streams (stipes and holdfasts) from S. latissima as a substrate for solid-state fermentation and to make initial total protein analyses of the product. The goal was to present a proof-of-concept – a model product – for future studies of e.g. amino acid composition, nutritional value, bioavailability, sensorics and environmental impact. The long-term impact target was to enable sustainable and profitable valorization of a presently unused side stream.

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  • 10.
    Casimir, Justin
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Gunnarsson, Carina
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Farmers current practices, and their opinion on supplying straw for production of second-generation biofuels in Sweden2020Report (Other academic)
    Abstract [en]

    This report presents results from the EU project AGROinLOG (Grant Agreement 727921) and especially focuses on the results from a survey looking at the current practices with straw use in Sweden as well as the farmer’s opinion on supplying straw for the production of second-generation biofuel. The survey was developed as a collaboration between LRF (Federation of Swedish farmers) RISE and Lantmännen.The reader can first read about the context within which the survey was developed and analysed. The questions and the methodology are then presented. The main part of the report presents the questionnaire results before drawing conclusions in line with the project’s objectives.The survey shows that about 60% of the straw from farmers participating in the survey, remains in the field while 40% is harvested mostly for animal production. The county of Skåne, the “ÖSÖ” region (Östergötland, Södermanland, and Örebro counties), the region including Uppsala, Stockholm and Västmanland counties, and the county of Västra Götaland have the largest potential for collection of straw for industrial processes in Sweden. However, farmers from these regions are the most concerned about the decrease of soil quality due to straw removal. The current common practices for straw handling in Sweden, including baling, collection, transport, storage and sale, are highlighted.Some interesting conclusions are drawn concerning the logistics needed for the handling of straw for the biobased industry. Moreover, the answers from the survey give some insights concerning a potential “straw contract” between Lantmännen and the farmers. The report also highlights the aspects to be further researched.More information concerning the Swedish contribution to the AGROinLOG project can be found in the public report AGROinLOG (2020a).

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  • 11.
    Chandolias, Konstantinos
    et al.
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources. University of Borås, Sweden.
    Sugianto, Laurenz Alan Ricardo
    Universitas Gadjah Mada, Indonesia.
    Izazi, Nurina
    Universitas Gadjah Mada, Indonesia.
    Millati, Ria
    Universitas Gadjah Mada, Indonesia.
    Wikandari, Rachma
    Universitas Gadjah Mada, Indonesia.
    Ylitervo, Päivi
    University of Borås, Sweden.
    Niklasson, Claes
    Chalmers University of Technology, Sweden.
    Taherzadeh, Mohammad J
    University of Borås, Sweden.
    Protective effect of a reverse membrane bioreactor against toluene and naphthalene in anaerobic digestion.2022In: Biotechnology and applied biochemistry, ISSN 0885-4513, E-ISSN 1470-8744, Vol. 69, no 3, p. 1267-1274Article in journal (Refereed)
    Abstract [en]

    Raw syngas contains tar contaminants including toluene and naphthalene, which inhibit its conversion to methane. Cell encasement in a hydrophilic reverse membrane bioreactor (RMBR) could protect the cells from hydrophobic contaminants. This study aimed to investigate the inhibition of toluene and naphthalene and the effect of using RMBR. In this work, toluene and napthalene were added at concentrations of 0.5 - 1.0 and 0.1 - 0.2 g/L in batch operation. In continuous operation, concentration of 0 - 6.44 g/L for toluene and 0 - 1.28 g/L for napthalene were studied. The results showed that no inhibition was observed in batch operation for toluene and naphthalene at concentrations up to 1 and 0.2 g/L, respectively. In continuous operation of free cell bioreactors (FCBR), inhibition of toluene and naphthalene started at 2.05 g/L and 0.63 g/L, respectively. When they were present simultaneously, inhibition of toluene and naphthalene occurred at concentrations of 3.14 g/L and 0.63 g/L, respectively. In continuous RMBRs, no inhibition for toluene and less inhibition for naphthalene were observed, resulting in higher methane production from RMBR than that of FCBR. These results indicated that RMBR system gave a better protection effect against inhibitors compared to FCBR. 

  • 12.
    Chen, Genqiang
    et al.
    Donghua University, China; Umeå University, Sweden.
    Wu, Guochao
    Umeå University, Sweden.
    Alriksson, Björn
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, Processum.
    Wang, Wei
    Donghua University, China.
    Hong, Feng F.
    Donghua University, China.
    Jönsson, Leif J.
    Umeå University, Sweden.
    Bioconversion of waste fiber sludge to bacterial nanocellulose and use for reinforcement of CTMP paper sheets2017In: Polymers, E-ISSN 2073-4360, Vol. 9, no 9, article id 458Article in journal (Refereed)
    Abstract [en]

    Utilization of bacterial nanocellulose (BNC) for large-scale applications is restricted by low productivity in static cultures and by the high cost of the medium. Fiber sludge, a waste stream from pulp and paper mills, was enzymatically hydrolyzed to sugar, which was used for the production of BNC by the submerged cultivation of Komagataeibacter xylinus. Compared with a synthetic glucose-based medium, the productivity of purified BNC from the fiber sludge hydrolysate using shake-flasks was enhanced from 0.11 to 0.17 g/(L × d), although the average viscometric degree of polymerization (DPv) decreased from 6760 to 6050. The cultivation conditions used in stirred-tank reactors (STRs), including the stirring speed, the airflow, and the pH, were also investigated. Using STRs, the BNC productivity in fiber-sludge medium was increased to 0.32 g/(L × d) and the DPv was increased to 6650. BNC produced from the fiber sludge hydrolysate was used as an additive in papermaking based on the chemithermomechanical pulp (CTMP) of birch. The introduction of BNC resulted in a significant enhancement of the mechanical strength of the paper sheets. With 10% (w/w) BNC in the CTMP/BNC mixture, the tear resistance was enhanced by 140%. SEM images showed that the BNC cross-linked and covered the surface of the CTMP fibers, resulting in enhanced mechanical strength.

  • 13.
    Cheregi, Otilia
    et al.
    University of Gothenburg, Sweden.
    Pinder, Matthew I.M.
    University of Gothenburg, Sweden.
    Shaikh, Kashif Mohd
    University of Gothenburg, Sweden.
    Andersson, Mats X.
    University of Gothenburg, Sweden.
    Engelbrektsson, Johan
    RISE Research Institutes of Sweden, Materials and Production, Chemistry, Biomaterials and Textiles.
    Strömberg, Niklas
    RISE Research Institutes of Sweden, Materials and Production, Chemistry, Biomaterials and Textiles.
    Ekendahl, Susanne
    RISE Research Institutes of Sweden, Materials and Production, Chemistry, Biomaterials and Textiles.
    Kourtchenko, Olga
    University of Gothenburg, Sweden.
    Godhe, Anna
    University of Gothenburg, Sweden.
    Töpel, Mats
    University of Gothenburg, Sweden; IVL Swedish Environmental Research Institute, Sweden.
    Spetea, Cornelia
    University of Gothenburg, Sweden.
    Transcriptome analysis reveals insights into adaptive responses of two marine microalgae species to Nordic seasons2023In: Algal Research, ISSN 2211-9264, article id 103222Article in journal (Refereed)
    Abstract [en]

    There is an increasing interest in algae-based biomass produced outdoors in natural and industrial settings for biotechnological applications. To predict the yield and biochemical composition of the biomass, it is important to understand how the transcriptome of species and strains of interest is affected by seasonal changes. Here we studied the effects of Nordic winter and summer on the transcriptome of two phytoplankton species, namely the diatom Skeletonema marinoi (Sm) and the eustigmatophyte Nannochloropsis granulata (Ng), recently identified as potentially important for biomass production on the west coast of Sweden. Cultures were grown in photobioreactors in simulated Nordic summer and winter, and the gene expression in two phases was quantified by Illumina RNA-sequencing. Five paired comparisons were made among the four conditions. Sm was overall more responsive to seasons since 70 % of the total transcriptome (14,783 genes) showed differential expression in at least one comparison as compared to 1.6 % (1403 genes) for Ng. For both species, we observed larger differences between the seasons than between the phases of the same season. In summer phase 1, Sm cells focused on photosynthesis and polysaccharide biosynthesis. Nitrate assimilation and recycling of intracellular nitrogen for protein biosynthesis were more active in summer phase 2 and throughout winter. Lipid catabolism was upregulated in winter relative to summer to supply carbon for respiration. Ng favored lipid accumulation in summer, while in winter activated different lipid remodeling pathways as compared to Sm. To cope with winter, Ng upregulated breakdown and transport of carbohydrates for energy production. Taken together, our transcriptome data reveal insights into adaptive seasonal responses of Sm and Ng important for biotechnological applications on the west coast of Sweden, but more work is required to decipher the molecular mechanisms behind these responses.

  • 14.
    Chinga-Carrasco, Gary
    et al.
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Syverud, Kristin
    RISE, Innventia, PFI – Paper and Fiber Research Institute.
    Pretreatment-dependent surface chemistry of wood nanocellulose for pH-sensitive hydrogels2014In: Journal of biomaterials applications, ISSN 0885-3282, E-ISSN 1530-8022, Vol. 3, no 29, p. 423-432Article in journal (Refereed)
    Abstract [en]

    Nanocellulose from wood is a promising material with potential in various technological areas. Within biomedical applications, nanocellulose has been proposed as a suitable nano-material for wound dressings. This is based on the capability of the material to self-assemble into 3D micro-porous structures, which among others have an excellent capacity of maintaining a moist environment. In addition, the surface chemistry of nanocellulose is suitable for various applications. First, OH-groups are abundant in nanocellulose materials, making the material strongly hydrophilic. Second, the surface chemistry can be modified, introducing aldehyde and carboxyl groups, which have major potential for surface functionalization. In this study, we demonstrate the production of nanocellulose with tailor-made surface chemistry, by pre-treating the raw cellulose fibres with carboxymethylation and periodate oxidation. The pre-treatments yielded a highly nanofibrillated material, with significant amounts of aldehyde and carboxyl groups. Importantly, the poly-anionic surface of the oxidized nanocellulose opens up for novel applications, i.e. micro-porous materials with pH-responsive characteristics. This is due to the swelling capacity of the 3D micro-porous structures, which have ionisable functional groups. In this study, we demonstrated that nanocellulose gels have a significantly higher swelling degree in neutral and alkaline conditions, compared to an acid environment (pH 3). Such a capability can potentially be applied in chronic wounds for controlled and intelligent release of antibacterial components into biofilms.

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  • 15. Ciranna, Alessandro
    et al.
    Pawar, Sudhanshu
    Santala, Ville
    Karp, Matti
    van Niel, Ed W. J.
    Assessment of metabolic flux distribution in the thermophilic hydrogen producer Caloramator celer as affected by external pH and hydrogen partial pressure.2014In: Microbial Cell Factories, ISSN 1475-2859, E-ISSN 1475-2859, Vol. 13, no 1, article id 48Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Caloramator celer is a strict anaerobic, alkalitolerant, thermophilic bacterium capable of converting glucose to hydrogen (H2), carbon dioxide, acetate, ethanol and formate by a mixed acid fermentation. Depending on the growth conditions C. celer can produce H2 at high yields. For a biotechnological exploitation of this bacterium for H2 production it is crucial to understand the factors that regulate carbon and electron fluxes and therefore the final distribution of metabolites to channel the metabolic flux towards the desired product.

    RESULTS: Combining experimental results from batch fermentations with genome analysis, reconstruction of central carbon metabolism and metabolic flux analysis (MFA), this study shed light on glucose catabolism of the thermophilic alkalitolerant bacterium C. celer. Two innate factors pertaining to culture conditions have been identified to significantly affect the metabolic flux distribution: culture pH and partial pressures of H2 (PH2). Overall, at alkaline to neutral pH the rate of biomass synthesis was maximized, whereas at acidic pH the lower growth rate and the less efficient biomass formation are accompanied with more efficient energy recovery from the substrate indicating high cell maintenance possibly to sustain intracellular pH homeostasis. Higher H2 yields were associated with fermentation at acidic pH as a consequence of the lower synthesis of other reduced by-products such as formate and ethanol. In contrast, PH2 did not affect the growth of C. celer on glucose. At high PH2 the cellular redox state was balanced by rerouting the flow of carbon and electrons to ethanol and formate production allowing unaltered glycolytic flux and growth rate, but resulting in a decreased H2 synthesis.

    CONCLUSION: C. celer possesses a flexible fermentative metabolism that allows redistribution of fluxes at key metabolic nodes to simultaneously control redox state and efficiently harvest energy from substrate even under unfavorable conditions (i.e. low pH and high PH2). With the H2 production in mind, acidic pH and low PH2 should be preferred for a high yield-oriented process, while a high productivity-oriented process can be achieved at alkaline pH and high PH2.

  • 16.
    Dahlbom, Sixten
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Anerud, Erik
    SLU Swedish University of Agricultural Sciences, Sweden.
    Lönnermark, Anders
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    Pushp, Mohit
    RISE Research Institutes of Sweden, Safety and Transport, Fire and Safety.
    A theoretical evaluation of the impact of the type of reaction on heat production and material losses in biomass piles2023In: Fire and Materials, ISSN 0308-0501, E-ISSN 1099-1018Article in journal (Refereed)
    Abstract [en]

    Self-heating during storage of biomass in piles causes material losses, leads to emissions to air, and poses a risk of fire. There are different techniques to assess a biomass material's propensity for self-heating, some of these are briefly reviewed. One of these techniques is isothermal calorimetry, which measures thermal power from materials and produces time-resolved curves. A recently developed and published test standard, ISO 20049-1:2020, describes how the self-heating of pelletized biofuels can be determined by means of isothermal calorimetry and how thermal power and the total heat produced during the test should be measured by isothermal calorimetry. This paper supports interpretation of the result obtained by isothermal calorimetry; the mentioned standard provides examples of peak thermal power and total heat but does not provide any assistance on how the result from isothermal measurements should be interpreted or how the result from measurements on different samples could be compared. This paper addresses the impact of different types of reactions, peak thermal power, total heat released (heat of reaction), activation energy, heat conductivity, and pile size on the temperature development in a generic pile of biomass. This paper addresses important parameters when the result from isothermal calorimetry is evaluated. The most important parameter, with respect to temperature development in large piles, was found to be the total heat released. It was also proposed that safe storage times, that is, the time until a run-away of the temperature in the pile, could be ranked based on the time to the peak thermal power.

  • 17.
    Edo, Mar
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Nilsson, Jamilla
    RISE Research Institutes of Sweden, Built Environment, Infrastructure and concrete technology.
    Sorting technologies: Case study about a MSW sorting facility in Norway - IVAR2022Report (Other academic)
    Abstract [en]

    The IVAR plant combines post-sorting of residual waste with recycling of some of the plastic waste fractions. At the plant five different fraction of plastics, four fractions of paper, bio- waste, glass, and metal packaging are separated. In total 83.2 % by weight of the incoming waste is sent to energy recovery (WtE) and 16.8 wt% is recovered for material recycling. It is estimated that approx. 82 wt% of the plastic in the waste is separated. Today they also have spare capacity to receive more waste for sorting, however the costs are relatively high and the economic incentive from the sales of the sorted materials are not enough. The largest renumeration comes from the Norwegian producer responsibility schemes for sorting plastic, metal packaging and beverage cartons.

    The bottle neck of the recycling industry with the current state of the art is the quality of the plastic waste. Only part of the plastic waste is suitable for recycling (have a market for the recycled material). New solutions for both plastic sorting and recycling is needed to increase the impact and circularity from the recycling. It will be crucial to find solutions for low quality and mixed plastic materials. There also need to be measures put in place to create a market pull for the recycled material.

    While all the recycled material generates positive climate effects, the recycled plastic generates double gains. It reduces the emissions for the production of virgin plastics and at the same time it reduces the direct fossil CO2 emissions generated by the WtE plant. Considering upcoming regulations in Norway, with increased CO2 taxes, the investments for more residual sorting plants in Norway is likely to increase.

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  • 18.
    Edo, Mar
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Waste-to-Energy and Social Acceptance: Copenhill Waste-to-Energy plant in Copenhagen2021Report (Other academic)
    Abstract [en]

    The construction of the Copenhill Waste-to-Energy (WtE) plant in a residential suburb in Copenhagen redefines the concept of a WtE plant. This is not just because of its location in a residential area and its special architecture, since that had already been achieved by Spittelau WtE plant in Wien (Austria); but rather for providing a multi-functional building with room for social and industrial activities in a sustainable manner and with good utilization of urban space. Copenhill represents an example of integration of WtE plants in an urban area and collaboration with the residents to achieve social acceptance in the activities developed by the waste and energy sector. In other words, Copenhill is the first WtE-plant of a new reinvented concept; there may be lessons in this for planned projects around the world, as a lack of community acceptance is often cited as a factor in unsuccessful proposals.

    Located only 2 km away from the Royal Palace, Copenhill is integrated into urban life with its innovative architectonic design offering a recreational area on the facility rooftop that includes an all year skiing slope, and a champagne bar for those who would like to visit, as well as a climbing wall on the facade.

    From a technical point of view, Copenhill was conceived from the idea of being a WtE plant showcase that Denmark could export to the world. Therefore, it was built using the best available technology to ensure the highest environmental performance and energy efficiency all in all in the safest environment. In addition, the construction site was used for training apprentices in works associated with the construction of WtE plants, providing economic benefit for the community.

    This case study describes technical and economic aspects of the Copenhill plant, and how Amager Resource Center (ARC), owners of Copenhill, and the residents in the city of Copenhagen found the way to share a common area in which everyone could feel safe and contribute to a more sustainable city while being a profitable business.

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  • 19.
    Fahnestock, Jesse
    RISE - Research Institutes of Sweden.
    AERTOs Bio-Based Economy: Forward-Looking Analysis2016Report (Other academic)
    Abstract [en]

    The Forward-Looking Analysis portion of the AERTOs Bio-Based Economy project seeks to develop contextual, exploratory analysis that helps the participating research institutes better evaluate their bioeconomy strategies. The analysis takes a 15-20 year perspective and focuses on the level of the bioeconomy, rather than on specific technologies or biorefinery concepts.

    The analysis contends that RTOs and their industrial partners should consider the uncertainties of the future bioeconomy at different levels – The World and Sustainability, Europe and the Bioeconomy, and the RTOs and Industry – and through the lenses of three alternative logics.

    The logic of environmental sustainability pushes the bioeconomy and its component technologies in the direction of large scale, efficiently incentivized substitution of fossil-based emissions through bio-based alternatives, benefiting biofuel production and creating opportunities for RTOs to take a leadership role in their work to make industrial bioeconomy more sustainable.

    The logic of competitive innovation pushes countries and companies to search for defensible advantages in the bioeconomy. The scale of fossil substitution is smaller but the margins for successful companies are higher, and advanced bio-based materials and chemicals are a dynamic sector for investment. The RTOs have a smaller role and work increasingly on product performance issues.

    The logic of resource utilization sees countries and companies working to maximize the value of existing assets, particularly natural biomass endowments. The bioeconomy is driven primarily through national strategies and the Forest Biorefinery creates national champions in the Nordics. RTOs have a stable workflow and focus on increasing the efficiency of biorefinery systems.

    Uncertainties related to the quantitative boundaries of the future bioeconomy can be assessed through a review of scenario literature on biomass availability, biofuels and bio-based chemicals production. There is a wide range of estimates available, but central estimates suggest that potential supply of sustainable biomass to industry could exceed demand by 70% in the long-term. Pressures created by changes at the margin of markets and through regional variations may nonetheless make realizing this potential difficult. Pathways applying the logic of environmental sustainability, to the extent that it generates common standards, will likely reduce supply-side risks.

    Because the transition to a bio-based economy will occur stepwise, accusations of ‘greenwashing’ may plague early bio-based products and strategies if they are not fully-fossil free or certified sustainable. Nonetheless these first attempts may also generate positive awareness and will need to continue in interplay with the development of standards and certifications. Pathways applying the logic of competitive innovation are likely to be those that create incentives for greenwashing and reputational risks to the bioeconomy.

    Uncertainties about feedstocks and technology costs have made feedstock flexibility a topic of interest in biorefinery development. Here, too, multiple concepts exist, from modular concepts that are truly feedstock agnostic to robust concepts designed to handle heterogeneity within a narrower feedstock basis. Once again the logical pathway applied will be likely to influence the approach to feedstock flexibility.

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  • 20.
    Federsel, Hans-Jürgen
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Chemical Process and Pharmaceutical Development.
    Moody, Thomas
    Almac Sciences Ltd, UK.
    Taylor, Steve
    Arran Chemical Company Ltd, Ireland.
    Recent trends in enzyme immobilization—concepts for expanding the biocatalysis toolbox2021In: Molecules, ISSN 1431-5157, E-ISSN 1420-3049, Vol. 26, no 9, article id 2822Article in journal (Refereed)
    Abstract [en]

    Enzymes have been exploited by humans for thousands of years in brewing and baking, but it is only recently that biocatalysis has become a mainstream technology for synthesis. Today, enzymes are used extensively in the manufacturing of pharmaceuticals, food, fine chemicals, flavors, fragrances and other products. Enzyme immobilization technology has also developed in parallel as a means of increasing enzyme performance and reducing process costs. The aim of this review is to present and discuss some of the more recent promising technical developments in enzyme immobilization, including the supports used, methods of fabrication, and their application in synthesis. The review highlights new support technologies such as the use of well-established polysaccharides in novel ways, the use of magnetic particles, DNA, renewable materials and hybrid organic–inorganic supports. The review also addresses how immobilization is being integrated into developing biocatalytic technology, for example in flow biocatalysis, the use of 3D printing and multi-enzymatic cascade reactions. © 2021 by the authors. 

  • 21.
    Fjellgaard Mikalsen, Ragni
    RISE - Research Institutes of Sweden, Safety and Transport, Fire Research Norway. Western Norway University of Applied Sciences, Norway; Otto von Guericke University Magdeburg, Germany.
    Fighting flameless fires: Initiating and extinguishing self-sustainedsmoldering fires in wood pellets2018Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Smoldering fires represent domestic, environmental and industrial hazards. This flameless form of combustion is more easily initiated than flaming, and is also more persistent and difficult to extinguish. The growing demand for non-fossil fuels has increased the use of solid biofuels such as biomass. This represents a safety challenge, as biomass self-ignition can cause smoldering fires, flaming fires or explosions.

    Smoldering and extinguishment in granular biomass was studied experimentally. The set-up consisted of a cylindrical fuel container of steel with thermally insulated side walls. The container was closed at the bottom, open at the top and heated from below by a hot surface. Two types of wood pellets were used as fuel, with 0.75-1.5 kg samples.

    Logistic regression was used to determine the transition region between non-smoldering and self-sustained smoldering experiments, and to determine the influence of parameters. Duration of external heating was most important for initiation of smoldering. Sample height was also significant, while the type of wood pellet was near-significant and fuel container height was not.

    The susceptibility of smoldering to changes in air supply was studied. With a small gap at the bottom of the fuel bed, the increased air flow in the same direction as the initial smoldering front (forward air flow) caused a significantly more intense combustion compared to the normal set-up with opposed air flow.

    Heat extraction from the combustion was studied using a water-cooled copper pipe. Challenges with direct fuel-water contact (fuel swelling, water channeling and runoff) were thus avoided. Smoldering was extinguished in 7 of 15 cases where heat extraction was in the same range as the heat production from combustion. This is the first experimental proof-of-concept of cooling as an extinguishment method for smoldering fires.

    Marginal differences in heating and cooling separated smoldering from extinguished cases; the fuel bed was at a heating-cooling balance point. Lower cooling levels did not lead to extinguishment, but cooling caused more predictable smoldering, possibly delaying the most intense combustion. Also observed at the balance point were pulsating temperatures; a form of long-lived (hours), macroscopic synchronization not previously observed in smoldering fires.

    For practical applications, cooling could be feasible for prevention of temperature escalation from self-heating in industrial storage units. This study provides a first step towards improved fuel storage safety for biomass. 

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  • 22.
    Fjäll, Stephanie
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Olsson, J
    Edström, Mats
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Gunnarsson, Carina
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Westlin, Hugo
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Myrbeck, Åsa
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    CASE STUDY ON SUSTAINABLE AND SELF-SUFFINCENT AGRICULTURE: INTEGRATING GRASS BIOREFINERY, ANEROBIC DIGESTION AND HYDROTHERMAL LIQUEFACTION2023In: Proc of EUBCE 2023, ETA-Florence Renewable Energies , 2023, p. 533-539Conference paper (Refereed)
    Abstract [en]

    The agricultural industry plays a crucial role in transitioning towards a sustainable and fossil-free future. This article explores the potential of biorefineries using biomass from agriculture to reduce emissions and promote self sufficiency. Regarding a concept that integrated anaerobic digestion, grass and legume protein production, and hydrothermal liquefaction. A case study was conducted in the southwestern part of Sweden, involving interviews with a biogas plant and local farmers. The study analyzed the utilization of input goods in agriculture and evaluated the potential of biomass in the area. To assess the potential for farms to become self-sufficient in fuel, protein feed, and plant nutrients. The results show an overall positive outlook of the biorefinery concept. By utilizing 20% of the available biomass in the area can the biorefinery concept annually produce 100 GWh of biogas, 3800 tonnes of grass and legume protein concentrate and 1200 GWh bio-oil. This could theoretically cover 100 % of the need of soy meal, 44% for nitrogen, 50% for phosphorus and 100% for potassium.

  • 23.
    Garami, Attila
    et al.
    University of Miskolc, Hungary.
    Toth-Pal, Zsolt
    RISE - Research Institutes of Sweden (2017-2019), Bioeconomy, ETC Energy Technology Center.
    Csordas, Bernadett
    University of Miskolc, Hungary.
    Palotas, Arpad
    University of Miskolc, Hungary.
    Reaction zone monitoring in biomass combustion2018In: Control Engineering Practice, ISSN 0967-0661, E-ISSN 1873-6939, Vol. 74, p. 95-106Article in journal (Refereed)
    Abstract [en]

    In this work we demonstrate the utilization of a machine vision-based combustion monitoring system in biomass combustion. The proposed system monitored the location of the reaction zone in a 3 MW, grate-fired biomass boiler operated at varying loads and with fluctuating fuel quality. The system can help guarantee equal primary air supply to different regions of the grate and avoid the elutriation of fly ash by providing information on the location of the reaction zone. Strong correlation was found between the reaction zone boundary location and most process parameters, indicating that the location of the reaction zone can be a useful metric in monitoring and control by providing supplementary measurements to already existing monitoring to avoid over-emissions and improve economics.

  • 24.
    Helberg, Ragne
    et al.
    NTNU Norwegian University of Science and Technology, Norway.
    Torstensen, Jonathan
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Dai, Zhongde
    NTNU Norwegian University of Science and Technology, Norway.
    Janakiram, Saravanan
    NTNU Norwegian University of Science and Technology, Norway.
    Chinga-Carrasco, Gary
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Gregersen, Øyvind
    NTNU Norwegian University of Science and Technology, Norway.
    Syverud, Kristin
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design. NTNU Norwegian University of Science and Technology, Norway.
    Deng, Liyuan
    NTNU Norwegian University of Science and Technology, Norway.
    Nanocomposite membranes with high-charge and size-screened phosphorylated nanocellulose fibrils for CO2 separation2021In: Green Energy and Environment, ISSN 2096-2797, Vol. 6, no 4, p. 585-Article in journal (Refereed)
    Abstract [en]

    In this study, cellulose nanofibrils (CNF) of high charge (H-P-CNF) and screened size (H-P-CNF-S) were fabricated by increasing the charge of phosphorylated cellulose nanofibrils (P-CNFs) during the pre-treatment step of CNF production. Results show that the H-P-CNF have a significantly higher charge (3.41 mmol g−1) compared with P-CNF (1.86 mmol g−1). Centrifugation of H-P-CNF gave a supernatant with higher charge (5.4 mmol g−1) and a reduced size (H-P-CNF-S). These tailored nanocelluloses were added to polyvinyl alcohol (PVA) solutions and the suspensions were successfully coated on porous polysulfone (PSf) supports to produce thin-film nanocomposite membranes. The humid mixed gas permeation tests show that CO2 permeability increases for membranes with the addition of H-P-CNF-S by 52% and 160%, compared with the P-CNF/PVA membrane and neat PVA membrane, respectively. 

  • 25.
    Hägg, Linus
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Johansson, Dennis
    RISE, SP – Sveriges Tekniska Forskningsinstitut.
    Vikberg, Tommy
    Luleå Technical University, Sweden.
    Influence of Fan Speed on Airflow distribution in a Scandinavian Drying Kiln2012Conference paper (Refereed)
    Abstract [en]

    From the beginning of the 90’s the development of drying kilns in Scandinavia has been focusing on increased drying capacity and also making the kilns more flexible in terms of handling differences in dimensions and initial moisture content. In order to facilitate the demand of higher airflows there has been an increase in circulation fan capacity. In a sawmill with modern kilns the fan capacity in a single batch kiln can be over 90 kW, making the drying kiln fans the single biggest consumer of electric power.Today, more and more sawmills are reviewing their consumption of electric power due to increasing prices. One way of reducing the consumption is to reduce the fan speed when the moisture content is so low that the drying rate is mainly limited by the diffusion properties of the wood and not the airflow. Since modern kilns are designed for high capacity fans there is a lack of knowledge of how a reduced fan speed affects the airflow distribution. This poses a risk of getting reduced quality of the final product due to increased moisture content variation in a batch.In this study the airflow has been measured inside an industrial drying kiln. For this study two experiments were done with 20 airflow gauges placed inside a kiln. During both experiments the kiln was fully loaded with pre dried Scotts pine (Pinus sylvestris) boards with a thickness of 50 mm. The reason for using pre-dried boards was simply that the gauge was not able to withstand the climate produced during a real process. In order to cover as much of the kiln as possible the gauges were distributed differently for the two experiments.The results show that about 30 % of the total airflow passes through the bolster spaces which are only about 20 % of the total flow area. This means that a notable volume of air might not be participating in drying of the boards.The results show also that the relative airflow distribution between the middle and the side of board stacks becomes more heterogeneous at a low fan speed. This trend is also seen for the relative distribution of airflow between bolster and sticker spaces.

  • 26.
    Jedvert, Kerstin
    et al.
    RISE - Research Institutes of Sweden, Swerea, Swerea IVF. Friedrich Schiller University Jena, Germany.
    Heinze, Thomas
    Friedrich Schiller University Jena, Germany.
    Cellulose modification and shaping – a review2017In: Journal of polymer engineering, ISSN 0334-6447, E-ISSN 2191-0340, Vol. 37, no 9, p. 845-860Article in journal (Refereed)
    Abstract [en]

    This review aims to present cellulose as a versatile resource for the production of a variety of materials, other than pulp and paper. These products include fibers, nonwovens, films, composites, and novel derivatized materials. This article will briefly introduce the structure of cellulose and some common cellulose derivatives, as well as the formation of cellulosic materials in the micro- and nanoscale range. The challenge with dissolution of cellulose will be discussed and both derivatizing and nonderivatizing solvents for cellulose will be described. The focus of the article is the critical discussion of different shaping processes to obtain a variety of cellulose products, from commercially available viscose fibers to advanced and functionalized materials still at the research level.

  • 27.
    Johansson, Inge
    et al.
    RISE Research Institutes of Sweden, Built Environment.
    Edo Giménez, Mar
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Roberts, Daniel
    CSIRO, Australia.
    Hoffman, Beau
    U.S. Department of Energy, USA.
    Becidan, Michael
    SINTEF Energy Research, Norway.
    Ciceri, Giovanni
    RSE Research on Energy Systems, Italy.
    Murphy, Fionnuala
    UCD University College Dublin, Ireland.
    Trois, Cristina
    University of kwaZulu-Natal, South Africa.
    Curran, Thomas P.
    UCD University College Dublin, Ireland.
    Stapf, Dieter
    Karlsruhe Institute of Technology, Germany.
    Material and energy valorization of waste as part of a circular model2023Report (Other academic)
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  • 28.
    Klemm, Dieter O.
    et al.
    KKF Polymers for Life, Germany.
    Lindström, Tom
    Stony Brook University, USA.
    Abitbol, Tiffany
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Kralisch, Dana
    Friedrich Schiller University Jena, Germany; JeNaCell GmbH, Germany .
    Chapter 1 - The nanocellulose family2021In: Nanocellulose Based Composites for Electronics, Elsevier , 2021Chapter in book (Other academic)
    Abstract [en]

    Cellulose is one of the most important natural raw materials and has been extensively used for more than 100 years in the form of paper and board materials, textiles, a large range of various cellulose derivatives, and many other applications. Over the past 15 years, fundamental research on novel cellulosic types has matured into several new fields of material and product development, which combine the outstanding properties of the natural product cellulose with the specific features of nanomaterials. Like other nanomaterials, these nanocelluloses are characterized by having at least one dimension in the nanometer range. The field of nanocellulosic materials is subdivided into three areas that differ significantly in terms of starting material, production method, and product properties. The members of the nanocellulose family are cellulose nanofibers (CNF), cellulose nanocrystals (CNC), and bacterial nanocellulose (BNC). The last one forms cellulose nano networks.

  • 29.
    Kotov, N.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Larsson, P. A.
    KTH Royal Institute of Technology, Sweden.
    Jain, K.
    KTH Royal Institute of Technology, Sweden.
    Abitbol, Tiffany
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Cernescu, A.
    Attocube systems AG, Germany.
    Wågberg, L.
    KTH Royal Institute of Technology, Sweden.
    Johnson, C. M.
    KTH Royal Institute of Technology, Sweden.
    Elucidating the fine-scale structural morphology of nanocellulose by nano infrared spectroscopy2023In: Carbohydrate Polymers, ISSN 0144-8617, E-ISSN 1879-1344, Vol. 302, article id 120320Article in journal (Refereed)
    Abstract [en]

    Nanoscale infrared (IR) spectroscopy and microscopy, enabling the acquisition of IR spectra and images with a lateral resolution of 20 nm, is employed to chemically characterize individual cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) to elucidate if the CNCs and CNFs consist of alternating crystalline and amorphous domains along the CNF/CNC. The high lateral resolution enables studies of the nanoscale morphology at different domains of the CNFs/CNCs: flat segments, kinks, twisted areas, and end points. The types of nanocellulose investigated are CNFs from tunicate, CNCs from cotton, and anionic and cationic wood-derived CNFs. All nano-FTIR spectra acquired from the different samples and different domains of the individual nanocellulose particles resemble a spectrum of crystalline cellulose, suggesting that the non-crystalline cellulose signal observed in macroscopic measurements of nanocellulose most likely originate from cellulose chains present at the surface of the nanocellulose particles. 

  • 30.
    Köhnlein, Maximilian
    et al.
    University of Borås, Sweden.
    Abitbol, Tiffany
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Osório Oliveira, Ana
    Karolinska Institute, Sweden.
    Magnusson, Mikael
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Adolfsson, Karin
    KTH Royal Institute of Technology, Sweden.
    Svensson, Sofie
    University of Borås, Sweden.
    Ferreira, Jorge
    University of Borås, Sweden.
    Hakkarainen, Minna
    KTH Royal Institute of Technology, Sweden.
    Zamani, Akram
    University of Borås, Sweden.
    Bioconversion of food waste to biocompatible wet-laid fungal films2022In: Materials & design, ISSN 0264-1275, E-ISSN 1873-4197, Vol. 216, article id 110534Article in journal (Refereed)
    Abstract [en]

    The fungus Rhizopus delemar was grown on bread waste in a submerged cultivation process and wet-laid into films. Alkali or enzyme treatments were used to isolate the fungal cell wall. A heat treatment was also applied to deactivate biological activity of the fungus. Homogenization of fungal biomass was done by an iterative ultrafine grinding process. Finally, the biomass was cast into films by a wet-laid process. Ultrafine grinding resulted in densification of the films. Fungal films showed tensile strengths of up to 18.1 MPa, a Young's modulus of 2.3 GPa and a strain at break of 1.4%. Highest tensile strength was achieved using alkali treatment, with SEM analysis showing a dense and highly organized structure. In contrast, less organized structures were obtained using enzymatic or heat treatments. A cell viability assay and fluorescent staining confirmed the biocompatibility of the films. A promising route for food waste valorization to sustainable fungal wet-laid films was established. © 2022 The Authors

  • 31.
    Lerman, Peter
    et al.
    Linnaeus University, Sweden.
    Scheepers, Gerhard
    RISE Research Institutes of Sweden, Built Environment, Building and Real Estate.
    Determination of a mass-transfer coefficient for wood drying by means of thermography2023In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280Article in journal (Refereed)
    Abstract [en]

    In the present work, it was demonstrated that mass transfer and mass transfer coefficients related to the wood drying process can be satisfactorily quantified using thermography. The method was based on continuous measurements of the wood’s surface temperature, which were converted to a vapor pressure at the wood surface. The results showed that the values of the experimentally obtained transfer coefficients were in the same order of magnitude as values obtained with classical empirical correlations that apply in boundary layer theory. The measurements also showed that an average value of the mass transfer coefficient obtained during drying satisfactorily describes the complete process. The measurement set-up makes it possible to determine a surface potential accurately and continuously, which is useful in the assessment of wood drying processes. © 2023 The Author(s). 

  • 32.
    Lestander, T. A.
    et al.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Weiland, Fredrik
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Grimm, A.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Rudolfsson, M.
    SLU Swedish University of Agricultural Sciences, Sweden.
    Wiinikka, Henrik
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Gasification of pure and mixed feedstock components: Effect on syngas composition and gasification efficiency2022In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 369, article id 133330Article in journal (Refereed)
    Abstract [en]

    The aim of this work was to investigate whether the use of individual tree components (i.e., stem wood, bark, branches, and needles of spruces) as feedstocks during oxygen blow gasification is more efficient than using mixtures of these components. Experiments were performed at three oxygen levels in an 18-kW oxygen blown fixed bed gasifier with both single and mixed component feedstocks. The composition of the resulting syngas and the cold gas efficiency based on CO and H2 (CGEfuel) were used as response variables to evaluate the influence of different feedstocks on gasification performance. Based on the experimental results and data on the composition of ∼26000 trees drawn from a national Swedish spruce database, multivariate models were developed to simulate gasifier performance under different operating conditions and with different feedstock compositions. The experimental results revealed that the optimal CGEfuel with respect to the oxygen supply differed markedly between the different spruce tree components. Additionally, the models showed that co-gasification of mixed components yielded a lower CGEfuel than separate gasification of pure components. Optimizing the oxygen supply for the average tree composition reduced the GCEfuel by 1.3–6.2% when compared to optimal gasification of single component feedstocks. Therefore, if single-component feedstocks are available, it may be preferable to gasify them separately because doing so provides a higher gasification efficiency than co-gasification of mixed components. © 2022 The Authors

  • 33.
    Lindahl, Carl
    et al.
    University of Gothenburg, Sweden; Uppsala University, Sweden.
    Xia, Wei
    University of Gothenburg, Sweden; Uppsala University, Sweden.
    Engqvist, Håkan
    University of Gothenburg, Sweden; Uppsala University, Sweden.
    Snis, Anders
    University of Gothenburg, Sweden; Arcam AB, Sweden.
    Lausmaa, Jukka
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik. University of Gothenburg, Sweden.
    Palmquist, Anders
    University of Gothenburg, Sweden.
    Biomimetic calcium phosphate coating of additively manufactured porous CoCr implants2015In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, Vol. 353, p. 40-47Article in journal (Refereed)
    Abstract [en]

    The aim of this work was to study the feasibility to use a biomimetic method to prepare biomimetic hydroxyapatite (HA) coatings on CoCr substrates with short soaking times and to characterize the properties of such coatings. A second objective was to investigate if the coatings could be applied to porous CoCr implants manufactured by electron beam melting (EBM). The coating was prepared by immersing the pretreated CoCr substrates and EBM implants into the phosphate-buffered solution with Ca2+ in sealed plastic bottles, kept at 60 °C for 3 days. The formed coating was partially crystalline, slightly calcium deficient and composed of plate-like crystallites forming roundish flowers in the size range of 300-500 nm. Cross-section imaging showed a thickness of 300-500 nm. In addition, dissolution tests in Tris-HCl up to 28 days showed that a substantial amount of the coating had dissolved, however, undergoing only minor morphological changes. A uniform coating was formed within the porous network of the additive manufactured implants having similar thickness and morphology as for the flat samples. In conclusion, the present coating procedure allows coatings to be formed on CoCr and could be used for complex shaped, porous implants made by additive manufacturing.

  • 34.
    Lund, Johanna
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Gunnarsson, Carina
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Fischer, Erik
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Chemistry and Materials.
    Sundberg, Martin
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Tersmeden, Marianne
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Outnyttjat ensilage till förnybar energi2018Report (Other academic)
    Abstract [en]

    There are large amounts of unutilized silage from agriculture and from municipalities that harvest meadows and grasslands. This biomass is a disposal problem and a cost. At the same time, there are biogas plants which have an increased demand for substrates that do not compete with the production of feed and food. Unutilized silage can be an excellent biogas substrate provided it is effectively pretreated. This study is conducted as a case study of Jordberga Biogas plant in Skåne (in the south of Sweden), although the results of the project are applicable to other regions in Sweden where unutilized silage exists. The project aim was to study a 20 % replacement

    of today’s crop-based substrates in Jordberga biogas plant with unutilized silage from agriculture and municipalities. The project has been conducted by RISE Agrifood and Bioscience in collaboration with the German Biomass Research Center (Deutsches Biomasseforschungszentrum, DBFZ), Gasum, County Administrative Board of Skåne and Fogda Farm.

    The project was divided into three parts. In the first part the amounts of different types of unutilized silage was estimated, from arable land and forage areas at municipalities and County Administrative Boards, for the area around the Gasum Biogas plant in Jordberga, and for Sweden in total. In a second part the adequate technique for pretreatment was identified and tested in practical trials on different types of unutilized silage. In the third part cost calculations were done for the disintegration of the unutilized silage.

    The study showed that the largest potential for unutilized silage is from forage production. The area of meadows is much less with much lower yield. An assumption was made that 5% of the total amount of unutilized silage bales are available for biogas production. Project calculations showed that 35% of these must be used to substitute 20% of the crop based substrates at Jordberga. Depending on the quality and biogas yield, 12-23 ton DM is needed per day.

    Based on earlier studies and experiences from the project group, three machines were chosen for the practical tests to disintegrate silage bales; Rot Grind, RS CutMaster and I-GRIND. Roto Grind and I-GRIND used hammermill technique whereas RS CutMaster

    used knife rotors for disintegration. All three machines managed to disintegrate silage bales with DM-content varying from 40-70% DM. The particle length after disintegration was analyzed and a visual estimation of the effect on particle structure was made. Particle size after disintegration was the same for Roto Grind and RS CutMaster whereas it was considerable longer for I-GRIND. Disintegration worked better on silage with lower DM content regarding both particle size and structure for all tested machines.

    Based on the test results RS CutMaster had higher total disintegration costs compared with Roto Grind and I-GRIND. The differences in costs was mainly due to lower measured capacity of RS CutMaster, and higher depreciation and maintenance costs of both RS CutMaster and I-GRIND. To lower the costs to same level as Roto Grind and I-GRIND, RS CutMaster would need approximately 40% higher capacity than measured in the tests.

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  • 35.
    Mei, Daofeng
    et al.
    Chalmers University of Technology, Sweden.
    Gogolev, Ivan
    Chalmers University of Technology, Sweden.
    Soleimanisalim, Amir H
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Lyngfelt, Anders
    Chalmers University of Technology, Sweden.
    Mattisson, Tobias
    Chalmers University of Technology, Sweden.
    Investigation of LD-slag as oxygen carrier for CLC in a 10 kW unit using high-volatile biomasses2023In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 127, article id 103940Article in journal (Refereed)
    Abstract [en]

    A steel slag from the Linz-Donawitz process, called LD-slag, having significant calcium and iron-fractions, was investigated as an oxygen carrier in a recently developed 10 kWth chemical-looping combustor with three high-volatile biomass fuels. In order to improve operability, the LD-slag was found to require heat-treatment at high temperatures before being used in the unit. In total, operation with the biomasses was conducted for more than 26 h at temperatures of 870–980 °C. The fuel thermal power was in the range of 3.4–10 kWth. The operation involved chemical looping combustion (CLC), chemical looping gasification (CLG) and oxygen carrier aided combustion (OCAC). Around 12 h was in CLC operation, 13.3 h was conducted in CLG-conditions, while the remaining 0.7 h was OCAC. Here, the results obtained during the CLC part of the campaign is reported. Increased temperature in the fuel reactor and higher airflows to the air reactor both lead to better combustion performance. Steam concentration in the fuel reactor has little effect on the performance. The LD-slag showed higher oxygen demand (31.0%) than that with ilmenite (21.5%) and a manganese ore (19.5%) with the same fuel and normal solids circulation. However, with the LD-slag, there is possibility to achieve a lower oxygen demand (15.2%) with high solids circulation. © 2023 The Author(s)

  • 36.
    Niklasson, Fredrik
    et al.
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    Gustavsson, Lennart
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    Ryde, Daniel
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    Johansson, Mathias
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    Persson, Henrik
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    Schüßler, Ingmar
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy.
    Branschgemensam forskning för småskaliga biobränslepannor inför ekodesign2018Report (Other academic)
    Abstract [en]

    New domestic biofuel boilers must meet the Ecodesign Directive by 2020. In a market survey from 2014, none of 11 tested pellet boilers did meet all requirements, clearly indicating a developmental need. In the present project boiler manufacturers and research institutes have collaborated in response to the combustion engineering challenges.

    For pellet boilers, the biggest challenge with the Ecodesign Directive is that performance is largely calculated from partial load operation (low load). Previously, performance has only been determined at nominal load and the design has been optimized accordingly. In this project, tests have been run with two modern pellet boilers that have different types of pellet burner: one with horizontal burner tube and one with an underfeed burner cup. The results show that sufficient combustion performance could be maintained at partial load with both burner types. However, the tube burner exhibited significantly lower emissions at partial loads, probably due to the combustion zone in this burner being protected from heat radiation exchange with cooling boiler walls. A rather extensive work was laid down to provide the cup burner with a protective collar that would protect the combustion zone. However, it did not result in any significant improvement, probably because the supply of secondary air did not become optimal. A more extensive work is required to develop an optimal burner design of this type.

    For wood log boilers, it is a challenge to comply with the NOx requirements of the Ecodesign Directive of 200 mg / Nm³. A variety of temperature measurements in a wood log boiler resulted in the exclusion of thermal NOx formation. The boiler was fitted with a flue gas recirculation system, but it did not reduce the NOx emission. Then different varieties of wood fuels were tested. The NOx emission could be reduced to meet the requirement using barked birch wood. Chemical analyzes showed that the birch bark contained 0.49% nitrogen compared to 0.09% in the stock. Spruce logs also gave low NOx emissions, but that fuel resulted in increased CO and OGC emissions. For wood log boilers to meet the requirements for CO, OGC and dust, optimization is required under the wood's final combustion phase. At this stage, emissions are at its highest, due to the decreasing heat output while the airflow tends to cool down the flue gas faster than the combustible gases burn out. The optical particle measurement showed a clear correlation between dust and CO in the flue gas. If the boiler meets the CO limit, there are good chances that the requirement for particles also will be met.

    The efficiency specified in the Ecodesign Directive is calculated based on the fuel's higher heating value. In addition, some loss factors are subtracted. This implies that the boiler must not have unnecessarily large heat losses or excessive electricity consumption to meet the requirements. Measurements showed that the biggest loss occurs with the heat in the flue gas. The second largest loss is heat from the boiler body. For the efficiency, the importance of a well-insulated boiler body increases in the case of partial loads. The two pellet boilers used in the project were well suited to meet the eco-directive directive's efficiency requirements.

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  • 37.
    Nissilä, Tuukka
    et al.
    University of Oulu, Finland.
    Wei, Jiayuan
    Luleå University of Technology, Sweden.
    Geng, Shiyu
    Luleå University of Technology, Sweden.
    Teleman, Anita
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Oksman, Kristiina
    Luleå University of Technology, Sweden;University of Toronto, Canada.
    Ice-templated cellulose nanofiber filaments as a reinforcement material in epoxy composites2021In: Nanomaterials, E-ISSN 2079-4991, Vol. 11, no 2, article id 490Article in journal (Refereed)
    Abstract [en]

    Finding renewable alternatives to the commonly used reinforcement materials in composites is attracting a significant amount of research interest. Nanocellulose is a promising candidate owing to its wide availability and favorable properties such as high Young’s modulus. This study addressed the major problems inherent to cellulose nanocomposites, namely, controlling the fiber structure and obtaining a sufficient interfacial adhesion between nanocellulose and a non-hydrophilic matrix. Unidirectionally aligned cellulose nanofiber filament mats were obtained via ice-templating, and chemical vapor deposition was used to cover the filament surfaces with an aminosilane before impregnating the mats with a bio-epoxy resin. The process resulted in cellulose nanocomposites with an oriented structure and a strong fiber–matrix interface. Diffuse reflectance infrared Fourier transform and X-ray photoelectron spectroscopy studies revealed the presence of silane on the filaments. The improved interface, resulting from the surface treatment, was observable in electron microscopy images and was further confirmed by the significant increase in the tan delta peak temperature. The storage modulus of the matrix could be improved up to 2.5-fold with 18 wt% filament content and was significantly higher in the filament direction. Wide-angle X-ray scattering was used to study the orientation of cellulose nanofibers in the filament mats and the composites, and the corresponding orientation indices were 0.6 and 0.53, respectively, indicating a significant level of alignment. © 2021 by the authors.

  • 38.
    Olsen, Elisabeth K.
    et al.
    UiT The Arctic University of Norway, Norway.
    Hansen, Espen
    UiT The Arctic University of Norway, Norway.
    Moodie, Lindon W. K.
    University of Umeå, Sweden.
    Isaksson, Johan
    UiT The Arctic University of Norway, Norway.
    Sepčić, Kristina
    University of Ljubljana, Slovenia.
    Cergolj, Marija
    University of Ljubljana, Slovenia; University of Rijeka, Croatia.
    Svenson, Johan
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor, Medicinteknik.
    Andersen, Jeanette H.
    UiT The Arctic University of Norway, Norway.
    Marine AChE inhibitors isolated from Geodia barretti: Natural compounds and their synthetic analogs2016In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 14, no 5, p. 1629-1640Article in journal (Refereed)
    Abstract [en]

    Barettin, 8,9-dihydrobarettin, bromoconicamin and a novel brominated marine indole were isolated from the boreal sponge Geodia barretti collected off the Norwegian coast. The compounds were evaluated as inhibitors of electric eel acetylcholinesterase. Barettin and 8,9-dihydrobarettin displayed significant inhibition of the enzyme, with inhibition constants (Ki) of 29 and 19 μM respectively towards acetylcholinesterase via a reversible noncompetitive mechanism. These activities are comparable to those of several other natural acetylcholinesterase inhibitors of marine origin. Bromoconicamin was less potent against acetylcholinesterase, and the novel compound was inactive. Based on the inhibitory activity, a library of 22 simplified synthetic analogs was designed and prepared to probe the role of the brominated indole, common to all the isolated compounds. From the structure-activity investigation it was shown that the brominated indole motif is not sufficient to generate a high acetylcholinesterase inhibitory activity, even when combined with natural cationic ligands for the acetylcholinesterase active site. The four natural compounds were also analysed for their butyrylcholinesterase inhibitory activity in addition and shown to display comparable activities. The study illustrates how both barettin and 8,9-dihydrobarettin display additional bioactivities which may help to explain their biological role in the producing organism. The findings also provide new insights into the structure-activity relationship of both natural and synthetic acetylcholinesterase inhibitors.

  • 39.
    Olsson, Carina
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, IVF.
    Sjöholm, Elisabeth
    RISE - Research Institutes of Sweden, Bioeconomy.
    Reimann, Anders
    RISE - Research Institutes of Sweden, Bioeconomy.
    Carbon fibres from precursors produced by dry-jet wet-spinning of kraft lignin blended with kraft pulps2017In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 71, no 4, p. 275-283Article in journal (Refereed)
    Abstract [en]

    A part of kraft lignin (KL) can be used as a value-added product without detracting the chemical recovery and the energy balance of the kraft mill. The focus of this study is the production of light-weight carbon fibres (CFS) from KL obtained by the LignoBoost process. For this purpose, crude KL and various cellulose products from kraft pulping of hardwood (HW) and softwood (SW) were dissolved in 1-ethyl-3-methylimidazolium acetate ([EMIm][OAc]) and submitted to dry-jet wet-spun to obtain precursor fibres containing 70% KL and 30% cellulose, which were thermally stabilised and further converted by thermal treatments into CF. The initial and final products were characterised with respect to, e.g. mole mass distribution, thermal properties, tensile strength and tensile modulus determination. The optimised precursor fibres are smooth and flexible with similar mechanical properties as commercial textile fibres. The best CFS made had a tensile strength of 780 MPa and a tensile modulus of 68 GPa and are thus stronger and stiffer than those produced by melt-spinning of SW-based lignins alone. The new CFS based on dry-jet wet-spun precursors still have a high potential for further improvements.

  • 40.
    Olszewska-Widdrat, Agata
    et al.
    Leibniz Institute for Agricultural Engineering and Bioeconomy, Germany.
    Xiros, Charilaos
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Wallenius, Anders
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Schneider, Roland
    Leibniz Institute for Agricultural Engineering and Bioeconomy, Germany.
    Rios da Costa Pereira, Lais Portugal
    Leibniz Institute for Agricultural Engineering and Bioeconomy, Germany.
    Venus, Joachim
    Leibniz Institute for Agricultural Engineering and Bioeconomy, Germany.
    Bioprocess optimization for lactic and succinic acid production from a pulp and paper industry side stream2023In: Frontiers in Bioengineering and Biotechnology, E-ISSN 2296-4185, Vol. 11, article id 1176043Article in journal (Refereed)
    Abstract [en]

    The effective and cheap production of platform chemicals is a crucial step towards the transition to a bio-based economy. In this work, biotechnological methods using sustainable, cheap, and readily available raw materials bring bio-economy and industrial microbiology together: Microbial production of two platform chemicals is demonstrated [lactic (LA) and succinic acid (SA)] from a non-expensive side stream of pulp and paper industry (fibre sludge) proposing a sustainable way to valorize it towards economically important monomers for bioplastics formation. This work showed a promising new route for their microbial production which can pave the way for new market expectations within the circular economy principles. Fibre sludge was enzymatically hydrolysed for 72 h to generate a glucose rich hydrolysate (100 g·L−1 glucose content) to serve as fermentation medium for Bacillus coagulans A 541, A162 strains and Actinobacillus succinogenis B1, as well as Basfia succiniciproducens B2. All microorganisms were investigated in batch fermentations, showing the ability to produce either lactic or succinic acid, respectively. The highest yield and productivities for lactic production were 0.99 g·g−1 and 3.75 g·L−1·h−1 whereas the succinic acid production stabilized at 0.77 g·g−1 and 1.16 g·L−1·h−1. Copyright © 2023 Olszewska-Widdrat, Xiros, Wallenius, Schneider, Rios da Costa Pereira and Venus.

  • 41.
    Opedal, Mihaela Tanase
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Ruwoldt, Jost
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Organosolv Lignin as a Green Sizing Agent for Thermoformed Pulp Products2022In: ACS Omega, E-ISSN 2470-1343, Vol. 7, no 50, p. 46583-46593Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to investigate the use of organosolv lignin as a sizing agent for thermoformed pulp products as a sustainable material with improved water resistance. For this purpose, an in-house-produced organosolv lignin from softwood (Norway Spruce) was mixed with bleached and unbleached chemi-thermomechanical pulp fibers. In addition, the isolated organosolv lignin was characterized by ATR-FTIR spectroscopy, size-exclusion chromatography, and thermogravimetric analysis. The analysis showed that organosolv lignin was of a high purity and practically ash-free, exhibiting low molecular weight, a glass transition temperature below the thermoforming temperature, and a high content of phenolic OH groups. The mechanical properties and water resistance of the organosolv lignin-sized thermoformed pulp materials were measured. A small decrease in strength and an increase in stiffness and density were observed for the lignin-sized thermoformed materials compared to the reference, that is, unsized materials. The addition of organosolv lignin decreased the wettability and swelling of the thermoformed product. These results are due to the distribution of organosolv lignin on the surface, filling in the pores and cavities, and providing a tighter fit within the thermoformed materials. In conclusion, the results from our study encourage the use of organosolv lignin as a sizing additive to thermoformed products, which can improve the water resistance to use it in sustainable packaging applications.

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  • 42.
    Paulsen Thoresen, Petter
    et al.
    Luleå university of technology, Sweden.
    Fahrni, Jonas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Lange, Heiko
    Luleå technical university, Sweden; University of Milano-Bicocca, Italy; NBFC National Biodiversity Future Center, Italy.
    Hertzog, Jasmine
    Université de Lorraine, France.
    Carré, Vincent
    Université de Lorraine, France.
    Zhou, Ming
    Luleå university of technology, Sweden.
    Trubetskaya, Anna
    Nord university, Norway.
    Aubriet, Frédéric
    Université de Lorraine, France.
    Hedlund, Jonas
    Luleå university of technology, Sweden.
    Gustafsson, Tomas
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Rova, Ulrika
    Luleå university of technology.
    Christakopoulos, Paul
    Luleå university of technology.
    Matsakas, Leonidas
    Luleå university of technology.
    On the understanding of bio-oil formation from the hydrothermal liquefaction of organosolv lignin isolated from softwood and hardwood sawdust2023In: Sustainable Energy & Fuels, E-ISSN 2398-4902Article in journal (Refereed)
    Abstract [en]

    Conversion of organosolv lignins isolated with and without an inorganic acid catalyst (H2SO4) from hard- and softwood (birch and spruce) into bio-oil through hydrothermal liquefaction has been investigated. Furthermore, fractions of the isolated bio-oils were catalytically deoxygenated to improve the bio-oil properties. As elucidated through NMR, both biomass source and extraction mode influence the bio-oil product distribution. Depending on whether the lignins carry a high content of native structures, or are depolymerized and subsequently condensed in the presence of sugar dehydration products, will dictate heavy oil (HO) and light oil (LO) distribution, and skew the HO product composition, which again will influence the requirements upon catalytical deoxygenation.

  • 43. Pawar, Sudhanshu
    Biohydrogen production from wheat straw hydrolysate using Caldicellulosiruptor saccharolyticus followed by biogas production in a two-step uncoupled process2013In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487Article in journal (Refereed)
  • 44.
    Pawar, Sudhanshu
    RISE.
    Biological Hydrogen Production from Lignocellulosic Biomass2016In: Enriched Methane: The First Step Towards the Hydrogen Economy / [ed] Marcello De Falco, Angelo Basile, Springer, 2016Chapter in book (Refereed)
  • 45. Pawar, Sudhanshu
    Thermophilic biohydrogen production: how far are we?2013In: Applied Microbiology and Biotechnology, ISSN 0175-7598, E-ISSN 1432-0614Article in journal (Refereed)
  • 46.
    Pawar, Sudhanshu S.
    et al.
    RISE. Lund University, Sweden.
    Vongkumpeang, Thitiwut
    Lund University, Sweden.
    Grey, Carl
    Lund University, Sweden.
    van Niel, Ed W. J.
    Lund University, Sweden.
    Biofilm formation by designed co-cultures of Caldicellulosiruptor species as a means to improve hydrogen productivity2015In: Biotechnology for Biofuels, ISSN 1754-6834, E-ISSN 1754-6834, Vol. 8, no 1, article id 19Article in journal (Refereed)
    Abstract [en]

    Background: Caldicellulosiruptor species have gained a reputation as being among the best microorganisms to produce hydrogen (H2) due to possession of a combination of appropriate features. However, due to their low volumetric H2 productivities (Q H2), Caldicellulosiruptor species cannot be considered for any viable biohydrogen production process yet. In this study, we evaluate biofilm forming potential of pure and co-cultures of Caldicellulosiruptor saccharolyticus and Caldicellulosiruptor owensensis in continuously stirred tank reactors (CSTR) and up-flow anaerobic (UA) reactors. We also evaluate biofilms as a means to retain biomass in the reactor and its influence on Q H2. Moreover, we explore the factors influencing the formation of biofilm. Results: Co-cultures of C. saccharolyticus and C. owensensis form substantially more biofilm than formed by C. owensensis alone. Biofilms improved substrate conversion in both of the reactor systems, but improved the Q H2 only in the UA reactor. When grown in the presence of each other's culture supernatant, both C. saccharolyticus and C. owensensis were positively influenced on their individual growth and H2 production. Unlike the CSTR, UA reactors allowed retention of C. saccharolyticus and C. owensensis when subjected to very high substrate loading rates. In the UA reactor, maximum Q H2 (approximately 20 mmol∈·∈L-1∈ ·∈h-1) was obtained only with granular sludge as the carrier material. In the CSTR, stirring negatively affected biofilm formation. Whereas, a clear correlation was observed between elevated (>40 μM) intracellular levels of the secondary messenger bis-(3′-5′)-cyclic dimeric guanosine monophosphate (c-di-GMP) and biofilm formation. Conclusions: In co-cultures C. saccharolyticus fortified the trade of biofilm formation by C. owensensis, which was mediated by elevated levels of c-di-GMP in C. owensensis. These biofilms were effective in retaining biomass of both species in the reactor and improving Q H2 in a UA reactor using granular sludge as the carrier material. This concept forms a basis for further optimizing the Q H2 at laboratory scale and beyond. © 2015 Pawar et al.; licensee BioMed Central.

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  • 47.
    Pawar, Sudhanshu S.
    et al.
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources.
    Werker, Alan
    Promiko AB, Sweden.
    Bengtsson, Simon
    Promiko AB, Sweden.
    Sandberg, Maria
    Karlstad University, Sweden.
    Langeland, Markus
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food. SLU Swedish University of Agricultural Sciences, Sweden.
    Persson, Magnus
    Paper Province AB, Sweden.
    Willquist, Karin
    RISE Research Institutes of Sweden, Built Environment, Energy and Resources. Fortum Recycling and Waste AB, Sweden.
    MultiBio: Environmental services from a multipurpose biorefinery2020Report (Other academic)
    Abstract [en]

    MultiBio project aimed to establish and demonstrate a novel multipurpose biorefinery cascade concept, producing three renewable biobased products: 1) biohydrogen, 2) biopolymers and 3) protein rich meal ingredients for fish farming. The cascade concept exploits the ability of a bacterium (Caldicellulosiruptor saccharolyticus) to transform nutrients present in low-value waste process waters of the pulp and paper industry, to high-value products hydrogen gas, organic acids and microbial biomass. The organic acid rich effluent will then be managed in an open culture microbial process used to achieve discharge water quality objectives and to produce polyhydroxyalkanoate (PHA) biopolymers. Moreover, since C. saccharolyticus protein content is more than 63% of cell dry weight, their potential in formulation of fish feed was evaluated. 

    A fiber sludge containing, CTMP residual stream was found to be a possible feedstock for the MultiBio process concept. Due to safety risks the demo-scale experiments of biohydrogen gas technology were moved from Biorefinery demo plant (Örnsköldsvik) of 40 m3 capacity to ATEX classified pilot-scale facility with 0.4 m3 capacity. Hence, bacterial biomass enough for the large-scale fish feed ingredient could not be produced. Lab-scale experiments with Caldicellulosiruptor cells as fish feed ingredient showed promising results as a protein-rich, sustainable fish feed ingredient. In addition, PHA biopolymer also showed favourable results as fish food ingredient for experiments at Gårdsfisk AB. Lab-scale experimental tests showed that the surplus activated sludge from the mills wastewater treatment could currently accumulate PHA to about 20 % of its dry weight. Mass balance evaluations based on realistically achievable expectations indicated a PHA biopolymer production potential of 3 600 tons of PHA per year from available organic residuals and for the two evaluated mills combined. 

    The MultiBio concept has a positive climate impact in comparison with current treatment and moves developments in a positive direction to achieve 7 of the 10 Swedish environmental goals. Through a detailed feasibility analysis, a natural progression in next steps in scenarios were suggested for PHA production. The MultiBio cascade process can be implemented with further necessary development with good business potential and a positive effect on climate change. However, biohydrogen technology needs further developments before this cascade process concept can be implemented. Alternatively, a scenario with only biopolymer technology shows already a significant business potential and even larger positive effect on climate change. A successful next step in demonstration of the PHA biopolymer production scenario may lead to it being implemented within the next few years. Furthermore, MultiBio has attracted a lot of attention regionally and nationally but also internationally with a total of 65 media listings. A licentiate thesis and three university degree projects linked to the project have been completed. Overall, the MultiBio project has successfully achieved its goals and objectives.

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  • 48.
    Pawar, Sudhanshu
    et al.
    Lund University, Sweden.
    van Niel, E. W. J.
    Lund University, Sweden.
    Evaluation of assimilatory sulphur metabolism in Caldicellulosiruptor saccharolyticus2014In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976Article in journal (Refereed)
  • 49.
    Petersson, Jeanette
    RISE - Research Institutes of Sweden, Bioeconomy, ETC Energy Technology Center.
    Pyrolysoljeproduktion i BOBIC:s värdekedja: en inledande förstudie2018Report (Other academic)
    Abstract [sv]

    Förhoppningar finns om att processer, som omvandlar skogsbaserade restprodukter från den skogliga värdekedjan till flytande drivmedel, ska kunna utgöra ett betydande bidrag till omställningen från fossilt till förnybart. Bland dessa processer finns produktion av biobaserad pyrolysolja som en potentiell kommersialiseringsmöjlighet. Detta projekt syftar till att utvärdera kommersialiseringsmöjligheten för pyrolysoljeproduktion inom BOBIC:s skogliga värdekedja, som återfinns i Norrbottens län, samt de fyra nordligaste kommunerna i Västerbottens län. Slutsatserna från projektet kan sammanfattas i 5 huvudsakliga punkter. - Pyrolysoljeproduktion i vår förstudie bygger på att som råvara nyttja olika typer av sidoströmmar; sågspån från sågverken, sållspån från bruken samt grot1.o Tillgången på råvara i regionen, i form av sågspån, begränsas till stor del av den stora pelletsproduktionen vid kusten. Ändras marknaden för pellets och det sker produktionsneddragningar, kan stora mängder sågspån göras tillgänglig.o För att ha tillräckligt mycket råvara för en pyrolysoljeanläggning måste sågspånet idag kompletteras med grot, antingen som råvara direkt i pyrolysanläggningen eller för att byta ut kvarvarande sågspån som eldas på sågverken med annat bränsle, så att sågspånet kan bli råvara för pyrolysolja. Det finns för närvarande inget uttag av grot i regionen, utan den marknaden måste byggas upp igen efter en tid av obefintligt uttag för att en pyrolysoljeanläggning skall vara möjlig.- Integration med antingen ett kraftvärmeverk eller ett massabruk är nödvändig för att den ekonomiska kalkylen för pyrolysoljeproduktion skall gå ihop. Detta sänker såväl driftkostnaden som kapitalkostnaden.- Med dagens förutsättningar kan pyrolysolja produceras till en kostnad på mellan 560 kr/MWh och 949 kr/MWh. Den stora skillnaden i produktionskostnaden ligger framför allt i bidrag till investering, råvarupriser och pyrolysoljeutbyte. Dessa siffror har en uppskattad osäkerhetsfaktor på ca 25%.- De stora industrierna som idag använder sig av eldningsolja, slipper i många fall betala energi- och koldioxidskatt på den, eftersom de jobbar med en kemisk process. Om detta ändras kommer pyrolysolja kunna vara mer konkurrenskraftig mot fossila alternativ på marknaden för eldningsoljor.- Vid försäljning av pyrolysoljan till raffinaderier, för uppgradering till biodrivmedel, kommer oljan få ett högre marknadsvärde på omkring 5000 – 6000 kr/ton. Dock ställer raffinaderierna större krav på produkten än om den skulle användas som eldningsolja. Den ska vara i princip helt askfri, samt ha en syrehalt på maximalt ~15 %.

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  • 50.
    Redlinger-Pohn, J. D.
    et al.
    KTH Royal Institute of Technology, Sweden.
    Brouzet, Christophe
    KTH Royal Institute of Technology, Sweden; Treesearch, Sweden; Wallenberg Wood Science Centre, Sweden; Aix Marseille Univ, Sweden.
    Aulin, Christian
    RISE Research Institutes of Sweden.
    Engström, Åsa
    RISE Research Institutes of Sweden, Bioeconomy and Health, Material and Surface Design.
    Riazanova, Anastasia
    Treesearch, Sweden.
    Holmqvist, Claes
    RISE Research Institutes of Sweden, Bioeconomy and Health, Pulp, Paper and Packaging.
    Lundell, Fredrik
    KTH Royal Institute of Technology, Sweden; Wallenberg Wood Science Centre, Sweden.
    Söderberg, L Daniel
    KTH Royal Institute of Technology, Sweden; Treesearch, Sweden; Wallenberg Wood Science Centre, Sweden.
    Mechanisms of Cellulose Fiber Comminution to Nanocellulose by Hyper Inertia Flows2022In: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 10, no 2, p. 703-719Article in journal (Refereed)
    Abstract [en]

    Nanocelluloses are seen as the basis of high-performance materials from renewable sources, enabling a bio-based sustainable future. Unsurprisingly, research has initially been focused on the design of new material concepts and less on new and adapted fabrication processes that would allow large-scale industrial production and widespread societal impact. In fact, even the processing routes for making nanocelluloses and the understanding on how the mechanical action fibrillates plant raw materials, albeit chemically or enzymatically pre-treated, are only rudimentary and have not evolved significantly during the past three decades. To address the challenge of designing cellulose comminution processes for a reliable and predictable production of nanocelluloses, we engineered a study setup, referred to as Hyper Inertia Microfluidizer, to observe and quantify phenomena at high speeds and acceleration into microchannels, which is the underlying flow in homogenization. We study two different channel geometries, one with acceleration into a straight channel and one with acceleration into a 90° bend, which resembles the commercial equipment for microfluidization. With the purpose of intensification of the nanocellulose production process, we focused on an efficient first pass fragmentation. Fibers are strained by the extensional flow upon acceleration into the microchannels, leading to buckling deformation and, at a higher velocity, fragmentation. The treatment induces sites of structural damage along and at the end of the fiber, which become a source for nanocellulose. Irrespectively on the treatment channel, these nanocelluloses are fibril-agglomerates, which are further reduced to smaller sizes. In a theoretical analysis, we identify fibril delamination as failure mode from bending by turbulent fluctuations in the flow as a comminution mechanism at the nanocellulose scale. Thus, we argue that intensification of the fibrillation can be achieved by an initial efficient fragmentation of the cellulose in smaller fragments, leading to a larger number of damaged sites for the nanocellulose production. Refinement of these nanocelluloses to fibrils is then achieved by an increase in critical bending events, i.e., decreasing the turbulent length scale and increasing the residence time of fibrils in the turbulent flow. © 2022 The Authors.

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