A group of young researchers from Canada, Finland and Sweden attended the MWP Prize Event in Stockholm in September 2014. The young researchers contributed to the MWP Symposium by presenting their own research in a poster exhibition, see the below abstracts.
- Fluidized bed pyrolysis of SunMembrane lignin
Author(s): Basel Al-Rudainy, Anders Arkell, Johanna Olsson, Lars Stigsson
Corresponding author: Basel Al-Rudainy
Affiliation: Lund University/KIRAM AB
E-mail: basel.al-rudainy@chemeng.lth.se
Abstract:
Black liquor is a by-product in the manufacture of pulp and paper in the kraft process. The treated black liquor is usually sent to a recovery boiler where the cooking chemicals are recovered and the organic materials, mostly lignin and hemicelluloses are incinerated to produce power and heat. In times of high demand, the recovery boiler is often a bottleneck for pulp mills. In-order to increase their productivity it is important to reduce the load on the recovery boiler with minimal impact on the process in its entirety. An economically favorable way of solving this problem is to reduce the amount of lignin with the SunMembrane process. The lignin can be sold as a raw material for the production of dispersants, polymers, carbon fibers or green fuel. To exploit the potential of lignin as a renewable raw material for fuels, a new conversion method is needed. Fluidized bed pyrolysis of lignin is a promising approach that is being investigated today. The resulting products from the pyrolysis of lignin are approximately 40wt% bio-oil and 50wt% bio-char. The phenolic-rich bio-oil can be used as a petrochemical substitution for the production of fuels. The plan is to start up a pilot plant for the production of bio-oil in the end of year 2014.
Keywords: Kraft black liquor, Lignin, green gasoline, green diesel, membrane filtration, fluidized bed pyrolysis
- Exfoliated MoS2 for paper based super capacitors
Author(s): Viviane Alecrim, Britta Andres, Renyun Zhang, Magnus Hummelgård, Nicklas Blomquist, Sven Forsberg, Ann-Christine Engström, Mattias Andersson, Håkan Olin
Corresponding author: Håkan Olin
Affiliation: Mid Sweden University
E-mail: hakan.olin@miun.se
Abstract:
Transition metal dichalcogenides (TMDs) have interesting electrical and mechanical properties. As they also present a 2D structure, much focus on these materials has been spent in the past few years to complement graphene. Since these materials are inert they are excellent for coating or printing on paper. In addition, these materials are environmental friendly and abundant allowing large-scale industrial employment. For most applications the layers in the material need to be separated. There are several methods for these, so called, exfoliation processes. However, more work is needed to develop proper methods, in particular for the less investigated TMD materials where the existing processes are either expensive, with low yields or employ hazardous solvents. Here we present an exfoliation method of MoS2, which is a TMD, using water only. The method employs sand paper grinding and disperging in water. A 15 g/L dispersion prepared with this method was employed in a composite of graphite, MoS2 and NFC (nanofibrillated cellulose) to produce electrodes for paper based supercapacitors. Higher specific capacitance was achieved for the electrodes with the dispersion prepared accordingly to the method described here. This method and results point towards the feasibility of large-scale paper based applications of layered materials.
Keywords: MoS2, mechanical exfoliation, EDLC, Paper based super capacitors, NFC
- Investigating the biomass modifying and degrading enzymatic toolbox of Aspergillus brunneoviolaceus FEC 156 with quantitative proteomics and New Generation Sequencing tools
Author(s): George E. Anasontzis, Thuy Nguyen Thanh, Thanh Vu Nguyen, Lisbeth Olsson
Corresponding author: George Anasontzis
Affiliation: Chalmers University of Technology
E-mail: george.anasontzis@chalmers.se
Abstract:
In the bio-based economy concept, the current hydrocarbon fuels and non-biodegradable plastics will be replaced by new products that will derive from natural and renewable resources. The synthesis of such biofuels and biochemicals is still challenged by the difficulties to degrade lignocellulosic materials to fermentable sugars or to isolate the intact polymers. Biomass degrading and modifying enzymes can play an integral role both in the separation of the polymers from the wood network, as well as in subsequent modifications, prior to further product development. The type of application usually defines the conditions where the reactions should take place. Thus, novel enzymes with variable combined properties, such as different thermotolerance, pH range of activity, substrate specificity and solvent tolerance, still need to be discovered and developed to achieve high efficiency for each application. We isolated an Aspergillus brunneoviolaceus and evaluated its cellulase and hemicellulases activities. It was then cultivated in bioreactors with different carbon sources and its biomass degrading capacity was determined and quantified with TMT (Tandem Mass Tags), through cross species protein identification of its secretome. Information on the genes involved in the different stages of the fermentation and carbon sources have been acquired with next generation sequencing of its total transcriptome. Interesting transcripts will be heterologously cloned and expressed in order to identify their role and potential use in the biorefinery concept.
Keywords: biomass-degrading enzymes, proteomics, transcriptomics, functional genomics, Aspergillus brunneoviolaceus
- Bio-based aromatic chemicals from wood biomass components
Author(s): Martta Asikainen, David Thomas, Juha Linnekoski, Antero Laitinen, Ali Harlin
Corresponding author: Martta Asikainen
Affiliation: VTT Technical Research Centre of Finland
E-mail: martta.asikainen@vtt.fi
Abstract:
Biorefineries target the optimised use of renewable feedstocks to a family of end products including bio-based chemicals. The forest biomass consists of different types of chemical components; cellulose, hemicellulose, lignin and extractives. The bulk of chemicals on the market today are produced from fossil feedstocks. With depleting fossil resources, it is vital to either discover processes for producing these chemicals from biomass, or alternative chemical products able to act as replacements. Targeting chemical processes and products where the use of the natural functionality of biomass is optimised leads to chemical processes with high atom-economy and good mass balances. The production of aromatic chemicals from biomass gives a good example. There are examples where heteroaromatic furan derivatives can act as replacements for currently used fossil sourced BTX (benzene, toluene, xylene) derivatives. The largest biomass reserve, carbohydrates, is better suited for the production of furan derivatives than BTX derivatives due to the chemical functionalities present in carbohydrates. On the other hand, Kraft pulping process by-product crude sulphate turpentine is well suited for producing BTX derivatives with high atom-economy. These two lines of research are examples of the current research activities of the corresponding author.
Keywords: Catalysis, Bio-based aromatics, Furans, Green chemistry
- Towards a methodology to assess sustainability of electronic waste supply-chains
Author(s): Ilaria Barletta
Corresponding author: Ilaria Barletta
Affiliation: Chalmers University of Technology
E-mail: Ilaria.barletta@chalmers.se
Abstract:
Stormy changes in technology and short product life-cycles often caused by today’s compulsive consumerism are likely to drive the global volume of electronic waste (e-waste) to 93.5 million tons in 2016 from 41.5 million tons in 2011. Are e-waste sector’s supply-chains ready to make good decisions to serve this demand by successfully meeting the triple-bottom-line (economic, environmental and social) sustainability? For this reason, my research aims to develop a methodology that assesses the level of sustainability of e-waste value chains by analyzing systems’ design of both single facilities and the whole reverse value chain from an operation management perspective. The challenges are to assess sustainability at each stage (e.g. collection, sorting, disassembly, recycling) and later to understand how to match the gate-to-gate assessments within a supply-chain scope to finally get the e-waste management positioning within the triple-bottom-line. The case-study research method will be used to set the use cases, to collect data and to validate the methodology. Moreover, simulation approaches, life-cycle assessment, and key performance indicators will be used as research tools. The goals are to provide organizations with a decision support tool for demanufacturing systems’ configurations and e-waste management strategies, paving the way to fully sustainable e-waste management systems.
Keywords: e-waste, WEEE, sustainability assessment, discrete event simulation, operation management, Key Performance Indicator
- Incorporating three pillars of sustainability in the design of forest biomass value chains
Author(s): Claudia Cambero, Taraneh Sowlati
Corresponding author: Claudia Cambero
Affiliation: University of British Columbia.
E-mail: cambero.claudia@gmail.com
Abstract:
The Northern Forest Products Industry could become a major player in the emerging bio-economy by converting forest biomass into bioenergy and/or bioproducts. In order to do this in a way that maximizes the overall value from forest resources, an optimal design of the forest biomass value chain is required. This design has to aim for a maximum economic benefit to achieve competitiveness and has to consider environmental and social aspects to generate community, government and investor’s buy-in. We are developing a multi-objective decision support tool that recommends: (1) biomass types and sources, (2) type, size and location of facilities, (3) type and amount of products, (5) markets, and (4) flow of biomass and products that maximize the profit and the number of jobs generated while minimizing greenhouse gas emissions. Through the generation of a set of Pareto-optimal solutions, our approach will show the sustainability compromises among alternative optimal solutions. We are applying this tool to a case study in west Canada to analyze the production of bioenergy and biofuels using available forest residues. Our approach could be modified for applications in other regions, providing decision makers with quantitative information to support the efficient and sustainable value generation from forest biomass.
Keywords: Forest biomass, sustainability, value chain, multi-objective optimization, decision support tool
7.Enzymatic modification of conventional kraft pulps for conversion to specialty grade cellulose
Author(s): Richard P. Chandra, Jack Saddler
Corresponding author: Richard Chandra
Affiliation: University of British Columbia
E-mail: Richard.Chandra@ubc.ca
Abstract:
One of the most attractive biorefinery options for unifying the production of fiber, chemicals and fuels is the prehydrolysis kraft pulping process that produces a purified specialty cellulose fiber/dissolving pulp feedstock, in addition to a sugar rich hemicellulose stream and a lignin rich black liquor that can be partially removed to reduce the strain on the kraft recovery boiler. However, the inherent resistance of biomass toward the purification of the cellulose component, and the propensity of the kraft process to preserve hemicellulose and high viscosity cellulose as part of the fiber furnish results in the implementation of additional cellulose purification/modification steps including prehydrolysis, caustic extraction, and hypochlorite bleaching. With their high specificity and ability to function at benign conditions enzymes such as hemicellulases and endoglucanases are prime candidates to tailor the properties of cellulose to reduce hemicellulose content and narrow the cellulose molecular weight distribution to provide a homogeneous polymer feedstock. In the work that will be described, xylanases and oxalic acid, a potentially biomimetic acid catalyst were compared for their ability to remove the last vestiges of hemicellulose from hardwood pulps, while assessing the resulting cellulose purity, molecular weight and accessibility. We found that xylanases were highly specific for the removal of residual hemicellulose, reducing the xylan content of the final pulp to about 1-2%. It is likely that the desirable properties resulting from the specific solubilisation of residual hemicellulose must be balanced against a potential reduction in the cellulose reactivity and accessibility of the dissolving pulp.
Keywords: Cellulose, Kraft Pulp, Xylanase, Oxalicacid, Xylan Cellulose, Dissolving pulp
- Crystalloid Structure of Cellulose and Its Implications
Author(s): Kevin Conley, Louis Godbout, Theo van de Ven, Tony Whitehead
Corresponding author: Kevin Conley
Affiliation: McGill University
E-mail: kevin.conley@mail.mcgill.ca
Abstract:
Cellulose exhibits properties of chirality at various levels within the crystalline and fibril structure, but is not taken into account in the current model of crystalline cellulose. It is unknown how these properties arise on the molecular level. Molecular Orbital Theory predicts the minimum energy conformation of isolated cellulose chains deviate from the two-fold symmetry assumed in diffraction measurements. These small deviations result in a structure with multiple twist periodicities, including a right-handed twist of 3.9 nm and a left-handed twist of 60 nm. Semi-empirical, Hartree-Fock, and Molecular Dynamics calculations were performed on isolated cellulose molecules as well as small crystals. These twists lend support to a hypothesis formulated more than twenty years ago, namely that the cellulose nanocrystal is actually a distorted, right-handed “crystalloid.” Such a structure would explain, through Straley’s well-known model of close-packed screws, why liquid crystalline suspensions of cellulose are chiral nematic rather than the expected nematic. A twist could also explain the presence of periodic amorphous regions along cellulose nanofibrils. Long-range twists have been observed microscopically in rare algal, animal and bacterial celluloses of large cross-sectional area, but cannot be observed directly on the smaller and more common cotton or wood celluloses. As modelling predicts that the twist increases with decreasing crystal cross-section, we propose an experimental scheme to detect the amount of twist, by comparing induced circular dichroism signals from cellulose crystals of varying sources, ranging from 20 X 20 nm to 3 X3 nm. Another important result of our modelling is that for very small arrays of cellulose chains initially arranged in the cellulose Iβ conformation, the distortions are such that we can no longer speak of a crystal or even a crystalloid. This may give insight into why cellulose crystals have a minimum cross-sectional dimension.
Keywords: Nanocrystalline cellulose, Microfibril twist, Cellulose crystal structure, Molecular Modelling
- Functionalization of nanocellulose aerogels for energy storage devices
Author(s): Johan Erlandsson, Lars Wågberg, Mats Sandberg, Hjalmar Granberg, Fredrik Berthold
Corresponding author: Johan Erlandsson
Affiliation: Royal Institute of Technology
E-mail: jerland@kth.se
Abstract:
Energy storage is one of the many obstacles encountered in the modern world and the problem spans several application areas from cell phones to electric vehicles. Fortunately the forest-based industry has potential to be a part of the future’s energy storage. The inherent large surface area of nanocellulose aerogels, made using wood as raw material, make them highly interesting for surface functionalization. Conducting nanoparticles and polyelectrolytes carrying a redox active entity can be adsorbed onto the surface using the layer-by-layer technique (LbL) and thus incorporate their respective function, conductivity and redox activity, into the cellulose aerogels. Conducting nano particles such as carbon nanotubes provides good conductivity and the electrochemically active polymers provides very fast charging, tunable voltages and completely metal free energy storage. Since the nanocellulose aerogels can be made as micrometer-sized particles this in turn opens the field for printed, light weight and renewable energy storage.
Keywords: Nanocellulose, redox active polymers, LbL, energy storage
- The Role of ‘Amorphogenesis’ in a Biorefinery
Author(s): Keith Gourlay, Richard Chandra, Jack Saddler
Corresponding author: Jack Saddler
Affiliation: University of Brittish Columbia
E-mail: Jack.saddler@ubc.ca
Abstract:
Enzymes can be used to modify cellulosic fibres for applications in higher value products, such as tissues and absorbents. It has recently been suggested that various enzymes can promote ‘amorphogenesis’ of cellulosic fibres. This process involves the opening-up and swelling of the fibres, without reducing the fibre mass. Amorphogenesis has great potential to enhance fibre structure for applications in tissues/absorbents, as well as to improve the reactivity of the fibres for other chemical or enzymatic processes. This work describes the effects of the amorphogenesis-inducing protein, Swollenin, on cellulosic biomass. Most enzymes acting on cellulosic substrates release a soluble product which is relatively easy to quantify. However, amorphogenesis-inducing enzymes do not produce a well-defined, soluble end product, making quantification of their activities challenging. In this work, a novel technique for quantifying amorphogenesis, involving the adsorption of substructure-specific carbohydrate binding modules (CBMs) is presented.
Keywords: Amorphogenesis, Swollenin, Enzymes, Fibre Modification, CBMs, Quantification, Microscopy
- New insight into rheology and flow properties of complex fluids with Doppler optical coherence tomography
Author(s): Sanna Haavisto, Juha Salmela, Antti Koponen
Corresponding author: Antti Koponen
Affiliation: VTT Technical Research Centre of Finland
E-mail: antti.koponen@vtt.fi
Abstract:
Flow properties of complex fluids such as colloidal suspensions, polymer solutions, fiber suspensions and blood have a vital function in many technological applications and biological systems. Yet, the basic knowledge on their properties is inadequate for many practical purposes. One important reason for this has been the lack of effective experimental methods that would allow detailed study of the flow behavior of especially opaque multi-phase fluids. Optical Coherence Tomography (OCT) is an emerging technique capable of simultaneous measurement of the internal structure and motion of most opaque materials, with high spatial and temporal resolution. For the first time a rheometer augmented with OCT reveals whether the rheometer measurement actually represents true material properties of the suspension or if the data is merely reflecting boundary layer phenomena. This will be essential new information for many materials and improve current material and flow models for these rheologically complex materials. In this work OCT data is also combined with Pulsed Ultrasound Doppler Velocimetry (PUDV) and magnetic resonance imaging (MRI) to study industrially relevant flow geometries. This enables a detailed study of the rheology of complex fluids in process flow environment where the behavior of the material (e.g. cellulose micro fibrils) is not restricted by the system size.
Keywords: Optical Coherence Tomography, complex fluids, rheology, cellulose microfibrils
- Nanocellulose-Assisted Aqueous Dispersion of Single-Wall Carbon Nanotubes
Author(s): Alireza Hajian and Mahiar M. Hamedi, Andreas B. Fall, Karl Håkansson, Michaela Salajkova, Fredrik Lundell, Lars Wågberg, Lars A. Berglund
Corresponding author: Alireza Hajian
Affiliation: Royal Institute of Technology
E-mail: hajian@kth.se
Abstract:
As-prepared Single-Wall Carbon nanotubes (SWCNTs) can be dispersed with the help of nanofibrillated cellulose (NFC), resulting in dispersions with high colloidal stability and quality that can be exploited into preparation of composites with high electrical conductivity and strength. Dispersing SWCNTs from bundles into individualized tubes in polymer matrices is challenging. Therefore, alternatives such as chemical functionalization and using surfactants have been used to improve its dispersion, both of which have their own repercussion on mechanical and electrical properties of the final composite. We hereby report a self-assembly route for creating inexpensive, strong and highly conductive NFC composites. This is made by showing the novel discovery that NFC itself can act as a superior dispersion and purification agent for SWCNTs in water. The quality of the NFC/SWCNT dispersions were carefully analyzed using Raman spectroscopy, UV-vis-NIR spectroscopy and dynamic light scattering. All the hybrids were further analyzed in terms of structural morphology, mechanical and electrical performance. We demonstrate that this dispersion is suitable for self-assembly of functional nanocomposites including random-network nanopaper, aerogel and anisotropic microfibers. These can be used in many applications such as electronic textiles, nanopaper substrates, energy storage devices and supercapacitors. Another step is to analyze the dispersion in order to understand the mechanism behind the favorable SWCNT dispersion and the effect of processing parameters. The goal is to reduce agglomeration of SWCNTs and increase SWCNT content.
Keywords: Nanocellulose, carbon nanotubes, dispersion, nanocomposites
- The Forgotten Potential of Sulphite-based Processes
Author(s): Saara Hanhikoski, Klaus Niemelä, Tapani Vuorinen
Corresponding author: Saara Hanhikoski
Affiliation: VTT Technical Research Centre of Finland
E-mail: saara.hanhikoski@vtt.fi
Abstract:
The current production of sulphite pulps, including paper-grade and semi-chemical pulps, accounts for approximately 5% of the world wood pulp production, and the capacity is predicted to increase. The advantages of sulphite processes include the versatility of process and a high flexibility in pulp yields, facilitating the production of specialized fibre products and the isolation of lignocellulosic materials from the spent liquors for conversion to various value-added products. Sulphite pulping at neutral or slightly alkaline pH is commonly known as a pre-treatment process of high yield semi-chemical (NSSC) pulp production for corrugating medium. However, the research on the utilization of NSSC spent liquors is still very limited. Extending the cooking at neutral pH chemical pulps with high yields of carbohydrates can be produced. The higher amounts of dissolved lignocellulosic materials in the spent liquors of extended neutral sulphite cooks can be utilized in the production of value-added by-products. The aim of this work is to examine the potential of forest biorefinery, based on neutral sulphite process for the production of tailored fibres, with simultaneous isolation of value-added by-products. The preliminary results show the significant glucomannan yield and the content of acidic groups in the produced pine sulphite pulps. Further research is needed to evaluate the potential of fibres in various applications and to define the most valuable materials to be isolated from the spent liquor.
Keywords: high yield sulphite pulp, sulphite spent liquor, neutral pH, glucomannan
- Antibacterial surface modification of nanocellulosic materials
Author(s): Jonatan Henschen, Per Larsson, Monica Ek, Lars Wågberg
Corresponding author: Jonatan Henschen
Affiliation: Royal Institute of Technology
E-mail: hens@kth.se
Abstract:
There is an increased use of antibiotics and other antimicrobial substances in the society today, this promotes the development of multi-resistant bacteria and causes environmental problems due to their toxicity for water living organisms. One way to achieve antimicrobial effects while simultaneously avoiding these problems is to irreversibly adsorb charged polymers onto materials. This is an environmentally friendly process that can be done at room temperature and only requires water as solvent. Previous studies show that by modifying cellulose fibers they can efficiently decrease the amount of viable bacteria and prevent growth of bacteria in solution. The adsorbed polymers act through contact, are non-leaching and do not spread into the environment. Nanocellulose is a green material being investigated as an alternative for a wide range of petrochemical products, one of them being packaging applications. This project focuses on producing antibacterial films made from nanocellulose that are suitable for packaging applications using technology that is safe and environmentally friendly.
Keywords: Antibacterial, Nanocellulose, Layer-by-layer.
- Development of tools for affecting cell-type directed alterations to secondary cell wall properties
Author(s): Christoffer Johnsson, Björn Sundberg, Urs Fischer
Corresponding author: Christoffer Johnsson
Affiliation: Stora Enso/SLU
E-mail: Christoffer.johnsson@slu.se
Abstract:
The composition of plant secondary cell walls deposited during growth determines the chemo-mechanical properties of the final woody biomass. Various industries look for different properties and, as such, no ideal biomass exists. Instead, industries have had to adapt production processes and attempt laborious, long term, breeding programs in order to deal with sub-optimal feedstock. The advent of new genetic engineering methods over the past decades offers the prospect of affecting changes to cell wall properties in a precise and rapid fashion. Trials have been performed and show promising results, but problems still remain, mainly how to change cell wall composition without negatively affecting growth. This has been a problem previously, as changes affecting cell walls made to all cell types often negatively impact vessel integrity, leading to collapses and, as a consequence, reduced ability to transport water and nutrients. Our strategy is initially to attempt to find a method of directing gene expression specifically to fibre cells and from there, to attempt to modify the composition of secondary cell walls in order to generate trees which are better optimized for certain production processes.
Such optimization would lead to a more efficient use of forest feedstock, needing less land and fewer resources for growth, and could allow industries, such as pulp mills, to use fewer chemicals and less energy, reducing both costs and environmental impact.
Keywords: Secondary cell wall, transcription factors, genetic engineering
- Bioactive stilbenes in Norway spruce: variability and localization within phloem and bark
Author(s): Tuula Jyske, in collaboration with Katsushi Kuroda, Dan Aoki, Andrey V. Pranovich, Bjarne R. Holmbom, Jussi-Petteri Suuronen, Harri Latva-Mäenpää, Pekka Saranpää, Kazuhiko Fukushima
Corresponding author: Tuula Jyske
Affiliation: The Finnish Forest Research Institute
E-mail: tuula.jyske@metla.fi
Abstract:
Hydroxylated stilbene derivatives (stilbenoids) are the major constituents of the bark extracts of Norway spruce (Picea abies (L.) Karst.) trees. These antioxidative, antifungal, and antimicrobial secondary metabolites are vital for tree resistance against pathogens, and of commercial interest. Optimal refining of spruce bark waste, and efficient valorisation of the phenolic compounds require knowledge on their distribution and regulation within trees and tissues. However, our current understanding on the biosynthesis, distribution and localization of stilbenes is still fragmentary. We are studying the obtainable stilbene yields, distribution and accumulation patterns, and seasonal variation in the stilbene content across the phloem and bark of Norway spruce stems. Chemical mapping of phloem and bark composition is studied by means of time-of-flight secondary-ion mass spectrometry (cryo-TOF-SIMS).
According to our research, the bark of Norway spruce trees from the first commercial thinnings, especially of butt and middle logs, is a feasible source for high-value extracts. The total yield of stilbene glucosides (astringin, isorhapontin, and piceid) from trees is dependent on the bark biomass, and positively correlated with total wood and bark volume. The basal stem is the most valuable stilbene source. Bark from one cubic meter of spruce timber may provide up to 1.6 kg of stilbenes. Within Norway spruce bark, the stilbene glucoside amount is highly variable. The proportions of different stilbene glucosides vary from inner to outer phloem and bark, suggesting changes in the metabolic activity across phloem. The TOF-SIMS imaging showed the highest concentrations of the stilbene compounds in the innermost bark. The compounds seem to be located mainly in the axial parenchyma cells. The observed trends in topochemical and quantitative chemical results appear to be linked to changes in parenchyma cell contents as visualized using electron microscopy and in 3D with synchrotron microtomography.
In our next steps, we attempt to relate the seasonal variation in stilbene content to the intra-annual dynamics of phloem formation, and link these to the molecular level mechanisms controlling phloem formation and stilbene biosynthesis. Also the applicability of bark and/or stilbene derivatives in different protective products will be studied.
Keywords: bark, biomass, localization, parenchyma, phloem, polyphenols, seasonality, stilbene glucosides
- Surface energy characterization of thermally modified wood using inverse gas chromatography
Author(s): Susanna Källbom, Magnus Wålinder, Kristoffer Segerholm, Dennis Jones
Corresponding author: Susanna Källbom
Affiliation: Royal Institute of Technology
E-mail: kallbom@kth.se
Abstract:
The research project is aiming at contributing to the development of durable and reusable wood-based building materials. A way of increasing the durability of wood is by thermal treatment. The treatment gives the material improved properties such as better resistance to decay and improved dimensional stability. Initial experiments have been performed to study the surface properties of thermally modified spruce components (<0.5mm) using inverse gas chromatography (IGC). IGC is a technique commonly used to study physicochemical properties of particles or fibres and could give information about changes in surface chemistry of modified materials. The technique is based on molecular interactions between the particulate material with unknown properties and various gas probes with known properties. The surface characterization can give information that may be useful for a better understanding and predictions of adhesion properties between the modified wood and other material systems, e.g. coatings, adhesives or matrices in composites. In this work, the dispersive surface energy at different fractional surface coverage of thermally modified wood was studied, with a target fractional surface coverage of up to 10% of the total surface. The results indicate that this new IGC approach involving analyses at different fractional surface coverages is a promising technique to measure the surface energy heterogeneity of the thermally modified wood component.
Keywords: thermally modified wood, inverse gas chromatography (IGC), surface energy
- Metal-Free Synthesis of Conjugated Polymers from Lignin-Based Vanillin
Author(s): Laure V. Kayser and Bruce A. Arndtsen
Corresponding author: Bruce A. Arndtsen
Affiliation: McGill University
E-mail: laure.kayser@mail.mcgill.ca
Abstract:
Conjugated polymers are an important class of electronic materials with potential applications as sensors, semiconductors, light-emitting devices, and solar cells.The synthesis of such compounds usually involves the transition metal-catalyzed coupling of petroleum-based monomers. This process, while effective, typically involves multiple synthetic steps, which increases the amount of chemical waste and costs. In addition, often required palladium catalysts can cause metal contamination of the material leading to a reduced device efficiency. In this context, a sustainable and facile approach to conjugated polymer would prove useful. Lignin is the only abundant aromatic natural polymer making it an attractive monomer source for conjugated polymers. However, there are very few studies describing the use of lignin-derived substrates in conjugated polymer synthesis. We have developed an efficient metal-free multicomponent synthesis of conjugated polymers using lignin degradation products as starting precursors. This approach uses simple materials and generates a complex polymer backbone in one step. A variety of conjugated polymers can be readily synthesized simply by choosing the initial components. It is therefore easy to tune the properties of these polymers to provide fluorescent materials for light-emitting devices or low band-gap materials for possible solar cell applications. Overall, this synthesis is a unique method to convert lignin-derived monomers into high value-added conjugated polymers in a single step, without metal contaminants, and with minimal waste. We are currently preparing devices to test the efficiency of these polymers.
Keywords: Conjugated polymers, renewable chemical feedstock, vanillin, metal-free synthesis
- Carbon Nanofibres from Cellulose as Electrodes for Supercapacitors
Author(s): V. Kuzmenko, H. Staaf, O. Naboka, M. M. Haque, P. Lundgren, P. Gatenholm, P. Enoksson
Corresponding author: Volodymyr Kuzmenko
Affiliation: Chalmers University of Technology
E-mail: kuzmenko@chalmers.se
Abstract:
Electric double-layer capacitors are efficient storage devices for high power density applications in electric automobiles, energy supplies for computers, phone chargers, etc. Carbon nanofibers (CNF) with well interconnected pores, high mechanical strength and electrochemical stability are prospective to be used as electrode materials in supercapacitors. They sustain a considerable uptake of electrolyte solution and enable high ion conductivity. The biopolymer cellulose is an inexhaustible source for the synthesis of CNF. In my research fibrous electrospun cellulose acetate are used for the synthesis of CNF sheets with the fiber diameter ranging from 70 to 400 nm. Impregnation of the cellulosic precursor with NH4Cl is utilized to improve CNF synthesis and dope the resultant carbon with nitrogen. As a result, impregnation leads to the increase of the carbon yield from 13% to 20%, while nitrogen-doping increases electrical conductivity and capacitance of the electrode material in comparison with the pristine samples. All the electrodes retain about 96% of the initial capacity over 1000 charge-discharge cycles, which indicates satisfactory cycle stability of electrode.
Keywords: cellulose, carbon nanofibers, nitrogen doping, supercapacitor
- Hydrophobic Materials Based on Cotton Linter Cellulose and an Epoxy-Activated Polyester Derived from a Suberin Monomer
Author(s): Dongfang Li, Tommy Iversen, Monica Ek
Corresponding author: Dongfang Li
Affiliation: Royal Institute of Technology
E-mail: dongfan@kth.se
Abstract:
Cellulose as the most naturally abundant polymer is widely used to prepare low density, low cost, and environmentally friendly materials with versatile functionalities. However, the hydrophilicity of cellulose is a crucial obstacle for some applications. Therefore, the interest in the hydrophobization of cellulose has driven increased attention. Generally, such goal could be achieved by introducing hydrophobic structures onto the surface of cellulose fibers. However, in many cases, the expensive, toxic, petro-based, and unrenewable chemicals are used in these processes. Natural products that are hydrophobic and renewable, such as suberin found in birch outer bark, could be the “greener” alternatives. Suberin as a polymer consists of many monomers, and cis-9,10-epoxy-18-hydroxyoctadecanoic acid (epoxy acid) is the most abundant among the others, amounting to approximately 100 g per kg of dried birch outer bark. The epoxy, hydroxyl, and carboxyl functional groups of the epoxy acid make it an interesting structure for polymerization and crosslinking. In this study, the epoxy acid was isolated from birch outer bark and then polymerized through enzymatic catalysis. The epoxy-activated polyester was used to modify a cellulose material by crosslinking the polyester on the cellulose surface. The materials showed increased hydrophobicity, mechanical properties, and decreased moisture uptake ability.
Keywords: cellulose, suberin, epoxy acid, polyester, hydrophobic
- Paper-enabled Organic Power Electronics
Author(s): Abdellah Malti, Jesper Edberg, Isak Engquist, Magnus Berggren, Xavier Crispin
Corresponding author: Abdellah Malti
Affiliation: Linköping Universitet
E-mail: abdellah.malti@liu.se
Abstract:
We report progress in developing a flexible self-standing paper-composite comprising a (semi)conducting polymer – namely, PEDOT:PSS – and nanofibrillated cellulose. The material exhibits excellent mechanical and electrical characteristics. It is also inherently self-adhesive which enables the material to be laminated and delaminated at will. This modular property opens the door for a plethora of applications where reconfigurability and ease-of-manufacturing are of prime importance. The PEDOT:PSS nanopaper composite acts as an active substrates and, thanks to a good bulk conductivity, can carry large current densities. In turn, this enables the material to be used in a variety of power electronics applications.
Keywords: cellulose,Organicpower electronics,PEDOTcomposite
- 3D Printing of Biopolymer Structures with Nanocellulose “ink”
Author(s): Kajsa Markstedt, Ivan Tournier, Athanasios Mantas, Daniel Hägg, Paul Gatenholm
Corresponding author: Kajsa Markstedt
Affiliation: Chalmers University of Technology
E-mail: kajsam@chalmers.se
Abstract:
As society strives to be environmental friendly, the interest for renewable resources such as wood derived biopolymers increases. For wood biopolymers to be a successful alternative to synthetic polymers it is crucial to develop technologies for conversion of wood resources into structures with controlled 3D architecture. 3D printing, a class of additive manufacturing, is an emerging technology which engages a variety of fields, from architectural to medical because of its ability to rapidly form complex and customized objects. The majority of 3D printing technologies has been developed for metals and thermoplastics, which most often are not renewable resources. In this work wood biopolymers are used as an ink for 3D printing, which opens a new world for wood based materials. Being that cellulose is not meltable, a 3D printing technology without a melting process has been used, called “3D bioprinting”. The studied ink consists of a suspension of nanofibrillated cellulose mixed with alginate. Rheology measurements show that the ink has shear thinning properties which is crucial for printing. Complex shapes with heights up to 1 cm have successfully been printed by the 3D bioprinter and by crosslinking with CaCl2, hydrogels with a three dimensional architecture were obtained. Developing the method of 3D printing wood biopolymers will bring products to the market that are environmentally friendly where at the same time a controlled 3D structure is crucial, such as packaging, hygiene products, textiles, sensors, medicine tablets and scaffolds for tissue engineering.
Keywords: Bioprinting, Biopolymers, Cellulose, 3D printing
- Production of man-made cellulosic fibers by dry-jet wet spinning from a solution containing pulp dissolved in ionic liquid
Author(s): Anne Michud, Michael Hummel, Herbert Sixta
Corresponding author: Anne Michud
Affiliation: Aalto University
E-mail: anne.michud@gmail.com
Abstract:
The market for cellulose products is expanding worldwide. In 2012, the consumption of fiber was 83.5 million tons (The Fiber Year 2013) of which 6.2% corresponds to man-made cellulosic fibers, MMCF (Viscose/Rayon, Modal and Tencel® fibers). Due to the limited expansion potential of cotton production and the drawbacks of the currently commercialized viscose and Lyocell processes, new alternatives need to be developed to fill the so called future cellulose gap. Ionic liquids that have been a novel class of solvent in the focus of interest during the last few years offer a new possibility of producing MMCF. The so called IONCELL-F process using ionic liquid as solvent and developed at Aalto University is presented as an alternative to the currently used viscose and Lyocell processes for the production of MMCF. High tenacity fibers in the conditioned (65%) and wet state can easily be achieved, transcending the properties of commercial fibers. As a result, a scarf and a dress were successfully manufactured and thus predict a promising future for the IONCELL-F process. There is consequently a big opportunity for the Finnish (Forest) industry to develop a new Lyocell brand based on an ionic liquid-based spinning process. The high availability of raw material (pine/spruce and birch wood) and the best available technologies in sustainable wood fractionation for pulp production make Finland a favorable place for establishing such a new brand.
Keywords: Cellulose, Dry-jet wet spinning, Textile fiber, IONCELL-F process
- Towards capturing the full value of the tree
Author(s): Maria Nordström
Corresponding author: Maria Nordström
Affiliation: Forestry Research Institute of Sweden
E-mail: maria.nordstrom@skogforsk.se
Abstract:
Swedish forestry is facing challenges in keeping harvesting operations on a competitive level. Forest-based industries are demanding more and more specific products. Each sawmill has a more or less unique specification on length and diameter combinations for the logs they buy. Harvesting technology has, on the other hand, reached a mature state, leading to an unsufficient increase in productivity of forest work and thus decreased profitability. In addition, sustainability and environmental considerations are getting more and more important aspects to take into account. Meeting the challenges, there is large potential in developing the usage of today’s harvesting technology. In my research and development work, I focus on how to measure length and diameter with high precision at harvesting – the first link in the value chain. The measurements form the basis for deciding which logs to cut from each tree. High measurement precision allows small safety margins, leading to less waste and thus capturing more value from each tree while decreasing environmental impact. This will benefit both customer and forest owner. An important part of my work concerns transferring the knowledge to harvester operators and forest professionals where it is most needed.
Keywords: Harvester, measurement, wood value, value chain.
- A biomimicking approach for hemicellulose processing
Author(s): Petri Oinonen, Gunnar Henriksson
Corresponding author: Petri Oinonen
Affiliation: Royal Institute of Technology
E-mail: poinonen@kth.se
Abstract:
Today a large percentage of wood hemicelluloses are lost with waste streams in pulping processes. The proprietary processing concept that I have been developing during my PhD-studies takes advantage of waste streams, from e.g. mechanical pulping processes. With the developed technique, we can turn this untapped resource into valuable materials and chemicals. The core step relies in hemicelluloses bearing aromatic moieties that can be cross-linked by laccase oxidation and isolated by membrane-filtration. The increased molecular weight and thermal stability of the hemicelluloses greatly improves their usability. The key benefit for the mills is that unused waste streams can be upgraded into polymers with good material properties at a competitive price. The technology also reduces the organic material content in wastewaters resulting in savings in fresh water consumption in the mill. The polymers are useful in various applications. The primary target is the packaging barrier-film market where there is a strong growth and need for eco-friendly bioplastics to replace oil-based plastics. An integrated liquid packaging board mill could use this technique as an online process using the produced hemicelluloses for coating the paperboard in a dispersion coating process. The ECOHELIX-technology is currently undergoing pilot scale testing together with an industrial partner.
Keywords: Hemicellulose, mechanical pulping, laccase, barrier film, wastewater treatment
- Extraction of lignin from heat-treated kraft black liquors of different origin
Author(s): Johanna Olsson, Basel Al-Rudainy, Anders Arkell, Lars Stigsson
Corresponding author: Johanna Olsson
Affiliation: Lund University
E-mail: Johanna.Olsson@chemeng.lth.se
Abstract:
Production of pulp and paper is a large part of the Swedish forest industry. As the usage of paper is declining we need to find new ways of using the resources in order to save the industry. Lignin could be used as a raw material in a number of applications such as production of chemicals and fuel. Our research focuses on extracting a pure lignin from black liquor (BL) of different origins using membrane filtration as a first step. There are available techniques for the extraction of lignin, e.g. precipitation and filtration. However, some of them face problems when the origin of the BL shifts from softwood to hardwood. The precipitation- and filtration properties decline due to the higher amount of hemicelluloses in the BL originating from hardwood. This becomes a problem since many mills utilizes both hard- and softwood or a mixture of both. In our research we have found that a heat-treatment of the concentrated liquor that is to be subjected to precipitation and filtration will improve the filterability of the precipitated slurry. This could solve the problem with extraction of lignin from hardwood. By simply introducing an optional additional heat-treatment step before the precipitation, a continuous process of extracting lignin regardless of origin could be obtained.
Keywords: black liquor, membrane filtration, heat-treatment, precipitation, filtration
- Catalyst deactivation in catalytic fast pyrolysis of forest biomass
Author(s): Ville Paasikallio, Jani Lehto
Corresponding author: Ville Paasikallio
Affiliation: VTT Technical Research Centre of Finland
E-mail: ville.paasikallio@vtt.fi
Abstract:
Inside the European Union, the policy-driven demand for renewable fuels has opened up promising new opportunities for the valorization of forest biomass. This can be seen as one potential renewal pathway for the traditional forest industry. Diversification of the product portfolio to include more highly refined energy products, e.g. transportation fuels, is an approach that is already being pursued by some companies. Among the various conversion technologies, fast pyrolysis has been identified as a straightforward method for converting solid biomass into a liquid fuel, pyrolysis oil. However, due to its challenging physicochemical properties, pyrolysis oil requires upgrading before it can be used as a transportation fuel. The severity of the upgrading can be reduced by introducing a catalyst directly into the pyrolysis process. With this approach, which is known as catalytic fast pyrolysis (CFP), the primary biomass decomposition reactions are followed by secondary catalytic reactions taking place within the pyrolysis reactor. This results in a trade-off, where quality of the pyrolysis oil improves at the expense of the oil yield. Catalyst deactivation has been identified as a key parameter that affects the overall performance of the CFP process. This presentation will cover catalytic fast pyrolysis research that been carried out at VTT Technical Research Centre of Finland, with a special emphasis on catalyst deactivation. Various deactivation phenomena that have been observed in bench-scale experiments and in an extended pilot-scale experiment will be discussed.
Keywords: Catalytic fast pyrolysis, biomass, thermochemical conversion, zeolites, catalyst deactivation
- Dewatering and consolidation of microfibrillated cellulose composite web in wet pressing
Author(s): Juuso Rantanen, Thad C. Maloney
Corresponding author: Juuso Rantanen
Affiliation: Aalto University
E-mail: juuso.rantanen@aalto.fi
Abstract:
The forest based industries are currently in need for new innovations, as traditional product markets are no longer growing as they used to. Some of the most promising bio-based materials are the micro- and nanofibrillated celluloses (MFC and NFC). These materials have been studied extensively by several research groups around the world. While there is currently vast amount of information available on the use of MFC in potential applications, the challenges in manufacturing are still to be solved. These challenges are partly caused by the high swelling and surface area of MFC, which affect the dewatering of MFC suspensions negatively. In this study we demonstrate the feasibility to use typical wet pressing to dewater a composite web containing 20 wt-% of commercially available MFC, together with typical papermaking fillers (70 wt-%) and fibers (10wt-%). The results show that web consolidation in pressing and drying is remarkably different with the MFC composite compared to plain wood based fibers, and that press dewatering was shown to be even better with the MFC composite. After pressing the MFC composite forms a structure that remains relatively constant even after drying, whereas plain fibers show typical shrinking behavior. As a result of this study, we are able to understand the basic effects that MFC is causing in the material structure and dewatering processes. We conclude that it is possible to dewater MFC containing composites with press units that are already in use. Results presented here are one important step in realization of the manufacturing paradigm for future bio-based products.
Keywords: MFC, PCC, wet pressing, papermaking, composite, porosimetry
- How can we develop forest products for the future?
Author(s): Gustav Sandin, Magdalena Svanström, Greg Peters
Corresponding author: Gustav Sandin
Affiliation: SP Technical Research Institute of Sweden
E-mail: gustav.sandin@sp.se
Abstract:
Many industries want to use forest resources to mitigate climate change and reduce their dependency on non-renewable resources. If forest resources are to fulfil such expectations, the consequence may be more intensive and/or extensive forestry and an increase in associated environmental impacts. There is a risk of problem shifting: climate change and fossil dependency may be reduced by increasing pressure on, for example, biodiversity and water resources. Our research is about ensuring that such problem shifting does not occur, by improving the methodology for assessing the environmental performance of emerging forest products. This includes: improved assessments of the impacts of forest products on the climate, terrestrial biodiversity and on water systems; more robust modelling of the inherent uncertainties of emerging, or non-existent technologies; and more context-specific use of environmental assessments for the benefit of projects aimed at developing new forest products. The vision is technological development which is fundamentally different to that which led to the fossil-dependent society of today – development that is more conscious about, and responsive to, environmental concerns.
Keywords: Environmental assessment, Life cycle assessment, Sustainability assessment, Forest product, Wood-based products, R&D
- Towards a lignin based carbon fibre
Author(s): Hannah Schweinebarth, Rufus Ziesig, Darren Baker, Per Tomani
Corresponding author: Hannah Schweinebarth
Affiliation: Innventia AB
E-mail: Hannah.schweinebarth@innventia.com
Abstract:
Carbon fibre, made out of polyacrylonitril (PAN), petroleum pitch and rayon has been around since the 1950s. The material has many advantages: light weight, high ultimate tensile strength and modulus, electrical conductivity and heat resistance just to mention a few. However, today’s methods of manufacturing have high environmental impact and use costly raw materials. But change is coming. Imagine a material with similar desirable properties but instead of being petroleum based it is wood based. Lignin has, up until now, been viewed as an internal energy source for the pulp mill, but due to its inherent chemical make-up and competitive production cost for carbon fibre it is now looked at as a potential raw material. My research spans the whole lignin chain: from black liquor isolation to carbon fibre manufacturing, with the end goal of producing an economically viable and competitive product. Yet, more research is needed to produce high strength fibres. We are currently exploring the kraft lignin structure and the feasibility of tailoring the material to suit carbon fibre applications. Thermally treating the lignin precursor to reduce volatile emission during extrusion is an important treatment and rheological evaluation of the lignin melt viscosity help us to understand the potential for extrusion of lignin filaments. This shift towards greener carbon fibre production will benefit consumers as well as the forest industry. Kraft lignin offers new revenue streams, represents new job opportunities and creates environmental goodwill, whilst consumers benefit from a new carbon fibre source entering the market helping reduce end-user prices and carbon footprints.
Keywords: Kraft Lignin, Carbon Fibre, Thermal treatment
- From Wood Biopolymers to 3D Biomaterials
Author(s): Johan Sundberg, Kajsa Markstedt, Sanna Sämfors, Kristina Karlsson, Guillermo Toriz and Paul Gatenholm
Corresponding author: Johan Sundberg
Affiliation: Chalmers University of Technology
E-mail: sundberj@chalmers.se
Abstract:
Wood derived biopolymers are very attractive for biomaterial applications. However, due to strong molecular interactions between wood biopolymers in the secondary cell wall of trees the dissolution and further processing is challenging. Ionic liquids are powerful solvents that can be used to dissolve entire wood and fractionate it into separate wood biopolymers. Dissolution of cellulose and hemicelluloses is possible in ionic liquids such as 1-Ethyl-3-methylimidazolium acetate (EmimAc). We investigated the mechanical properties of cellulose and arabinoglucuronoxylan (AGX) blend films regenerated from (EmimAc) as a function of the film composition and the absorbed moisture. Using a 3D bioprinting process we were also able to fabricate complex 3D structures from wood derived biopolymers dissolved in ionic liquid. Another attractive route to build 3D biomedical biomaterials with controlled architecture is computer assisted bottom up fabrication using biopolymers derived from trees and/or bacterial sources. Ionic liquids and 3D bioprinting provides a new technology platform to manufacture 3D structures based on wood biopolymers for use in biomaterial applications such as drug delivery systems, wound healing materials, functional hygiene products and smart packaging.
Keywords: Wood Biopolymers; Ionic Liquid; 3D Bioprinting; 3D Biomaterials
- Development of a novel process for the production of an acetate-grade pulp from pine wood according to the biorefinery principle
Author(s): Terhi Toivari, Lidia Testova, Marc Borrega, Herbert Sixta
Corresponding author: Terhi Toivari
Affiliation: Aalto University
E-mail: terhi.toivari@aalto.fi
Abstract:
Today, approximately half of the dissolving wood pulp is manufactured by the prehydrolysis-Kraft process, in which the non-cellulosic polysaccharides are removed from wood by prehydrolysis prior to the pulping process. However, aqueous-phase prehydrolysis in batch mode is difficult to commercialize due to the formation of sticky lignin precipitates, whereas steam prehydrolysis does not allow the recovery of the hemicellulose-rich dissolved organic fraction. Hence, prehydrolysis by consecutive recirculation and percolation modes is seen as a process combining the advantages of both conventional aqueous-phase and steam pretreatments. The present study aims at the production of high purity pine dissolving pulps conforming to the acetate grade pulp requirements. Aqueous-phase prehydrolysis begins in the recirculation mode at elevated temperatures until an optimal removal of hemicelluloses is reached. Subsequently, the percolation mode with a continuous fresh water feed is applied in order to maximize the removal of hemicelluloses and to avoid further carbohydrate degradation and lignin recondensation. After prehydrolysis, the pulping process is completed by Kraft cooking, oxygen delignification, and bleaching.
Keywords: Dissolving pulp, acetate-grade pulp, prehydrolysis, biorefinery, Pinus sylvestris
- Formability of paper-based materials
Author(s): Alexey Vishtal, Elias Retulainen
Corresponding author: Alexey Vishtal
Affiliation: VTT Technical Research Centre of Finland
E-mail: alexey.vishtal@vtt.fi
Abstract:
Paper and paperboard are the most widely used packaging materials in the world. Paper and paperboard are recyclable, biodegradable, renewable, sustainable materials with excellent printing quality. This provides certain advantages over the most of the plastic-based packaging materials. Increasing environmental pressure is also one driver for the further growth of paper-based packaging market. However, paper packaging appears in rather simple geometrical forms while plastics can be formed to a great variety of different shapes. Formability is a complex mechanical property that determines the ease of forming of a material. Improvement of the formability is the key to unlock the way to production of novel paper-based packaging, and to increase its competitiveness over plastics. This work overviews various 3D-forming processes such as deep-drawing, vacuum-forming, and thermoforming, which can be used to form paper-based materials, as well as the requirements for the successful forming that depends on the material i.e. formability. The primary objective of this thesis work is to improve formability of the paper-based materials for the use in the thermoforming processes for production of sustainable packaging. Secondary aim is to characterize formability as the mechanical property of paper, and found factors that influence on it.
Keywords: extensibility, formability, packaging, paperboard, 3D forming
- Enzymatic modifications of cellulose in ionic liquids and deep eutectic solvents (DESs)
Author(s): Ronny Wahlström, Anna Suurnäkki
Corresponding author: Ronny Wahlström
Affiliation: VTT Technical Research Centre of Finland
E-mail: ronny.wahlstrom@vtt.fi
Abstract:
Multicomponent solvents like ionic liquids (ILs) and deep eutectic solvents (DESs) have lately attracted great interest due to their capability to dissolve cellulose, lignocellulosic biomass such as wood meal, or components thereof in a selective way. We have studied the use of enzymes (mainly cellulases) for cellulose modifications in IL and DES solutions. The aim is to modify the cellulose as a polymer instead of making only fibre surface modifications. The use of enzymes gives benefits such as mild reaction conditions and high reaction specificity. By finding suitable combinations of cellulases/hemicellulases and cellulose solvents, e.g. tailoring cellulose DP and hemicellulose removal can be possible in new innovative ways. Typically, cellulases are inactivated by cellulose-dissolving ILs and DESs, which necessitates studying the reasons for enzyme inactivation to design compatible enzyme+IL/DES systems. Our results showed that ILs severely inhibited the cellulose-binding of cellulases, which is important for hydrolysis. Cellulose-dissolving ILs are very basic but the basicity was found not to be a major inactivation reason. Several classes of cellulose-solvents were screened for enzyme-compatibility in hydrolysis experiments, but the enzymes’ hydrolytic action was low in IL solutions. One cellulose-dissolving IL stabilized cellulases and will be used in future studies. The modification of wood and cellulose in cellulose-dissolving ILs and DESs holds great future potential for designing new cellulose products and production processes, e.g. have new pulping methods using ILs/DESs been proposed.
Keywords: Ionic liquid, deep eutectic solvent, enzymatic modification, cellulase, hemicellulase, cellulose
- Effects of moose browsing on young Scots pine volume production
Author(s): Märtha Wallgren, Roger Bergström, Folke Pettersson, Hagos Lundström
Corresponding author: Märtha Wallgren
Affiliation: Forestry Research Institute of Sweden
E-mail: martha.wallgren@skogforsk.se
Abstract:
In Sweden moose and other cervids browse on young Scots pine during winter and to a lesser extent also during summer. The browsing may result in different types of stem damage (through e.g. stem breaking and bark stripping), as well as loss of green needle biomass (through consumption of lateral shoots). Damages lead to permanent and unwanted structural changes in the wood, from forestry point of view reductions in wood quality. The loss of green needle biomass reduces the photosynthetic ability of the trees and may thereby lead to reduced growth. The consequences of moose browsing for the Swedish forestry sector are probably very high yearly costs, but the extent of the economic losses has never been exactly determined, because relevant data are missing. Our research aims at determining the effects of low to medium browsing pressure on tree volume production and quality reductions in typical Swedish pine forests, as well as the final economic consequences of the browsing for the forestry sector. Ultimately, our research will increase the current knowledge about a sparsely studied aspect of tree-browser interactions, as well as help making wise and relevant future management decisions regarding this important issue for Swedish forest and wildlife sectors.
Keywords: Browsing, damage, forestry, moose, Scots pine, wildlife
- Synchrotron Radiation Based Research Meets Nanocellulose: Advanced Structure Analyses
Author(s): Shun Yu, Karl M. O. Håkansson, Fredrik Lundell, L. Daniel Söderberg
Corresponding author: Shun Yu
Affiliation: Royal Institute of Technology
E-mail: shuny@kth.se
Abstract:
Nanocellulose is one of the materials intensively studied by the wood science community, recently. The versatile applications of nanocellulose involve controlling and designing the materials’ assembly in nanoscale, where X-ray scattering techniques have very high sensitivity. The synchrotron radiation (SR) based X-ray characterization techniques provides the opportunities to study material structure in an unprecedented way with high temporal and spatial resolution. Sweden is becoming the next research centre, thanks to ongoing MAX IV laboratory project. My researches thus focus on understanding the structure and properties relationship of nanocellulose based biocomposites by using in situ X-ray technique at advanced SR facilities during fabrication and application. By mimicking the industrial fabrication setup in a smaller scale at the SR experimental station, such as microfluidic device, the nanocellulose assembling process in solution can be directly probed by X-ray under controlled conditions and the industrial fabrication parameters can be optimized accordingly. By using submicron focused X-ray beam, we could analyse the structure distribution on a single micro fibre assembled with nanocellulose fibrils. In the future, the advanced characterization techniques available at SR facility can directly impact on the industrial production by integrating with other in situ materials’ fabrication and performance test techniques.
Keywords: Synchrotron radiation, X-ray scattering, Structure analyses, nanocellulose, in situ
- Performance nature inspired materials – Moulded paper composites
Author(s): Yujia Zhang
Corresponding author: Yujia Zhang
Affiliation: OrganoClick AB
E-mail:Yujia.Zhang@organoclick.com
Abstract:
Moulded paper has been used for applications with low demand on surface finish and functionality, such as egg cartons. Recent improvements in paper moulding technology has resulted in a verity of new packaging products, including moulded paper cups and high quality packages with smooth surfaces. The products so far have however been rather small in size and with limited mechanical properties. Therefore, moulded fibre composite material is one of the most interesting projects that is under developing at OrganoClick. By combining the state-of-the art moulding technology with our fibre modification technology at OrganoClick, we enabled to produce large bio-fibre based items up to 2 meters in length together with high degree of strength, good stiffness and can also withstand dry, humid and cold conditions. At the same time, the composites have been created with functions such as fire resistance (to reach a controlled burning speed) and super hydrophobicity surface property. Applications of this technique include large products such as cheap, light, “green” coffins and furnitures, along with industrial applications such as automotive interior parts.
Keywords: Moulded paper, fibre modification, flame resistant, high mechanical properties
