A group of young researchers from Finland, Germany, Sweden and USA attended the Marcus Wallenberg Prize Event in Stockholm in September 2018. The young researchers contributed to the MWP Symposium by presenting their own research in a poster exhibition, see the below abstracts.
1: Up-grade of Kraft Lignin Fractionation, Chemical Modification and Valorization of Lignin for Different Applications
Author(s): Selda Aminzadeh, Dr. Olena Sevastyanova, Prof. Mikael Lindström
Corresponding author: Prof. Mikael Lindström, Dr. Olena Sevastyanova
Affiliation: KTH Royal Institute of Technology, school of engineering sciences in chemistry, biotechnology and health, Fibre and polymer technology department, Wallenberg wood science center, Stockholm,Sweden
E‐mail: email@example.com; firstname.lastname@example.org; email@example.com
Lignin, which is the second most abundant biomass and Kraft lignoBoost lignin as a major side product in pulp industry with very carbon-rich phenolic content, are a promising renewable raw materials for multiple applications. In order to utilize lignin efficiently and apply it for different applications, it is so important to ensure its purity and homogeneity. Therefore, the separation of lignin into fractions with high purity and narrow molecular-weight (Mw) distributions is an essential and demanded steps. In addition, due to the presence of active hydroxyl group in lignin, it has very high potential for further modifications with different substitution units to enhance its properties. In this work, ultrafiltration using ceramic membranes with some prominent benefits, i.e., enabling direct lignin extraction from Kraft pulp cooking liquors without pH and temperature adjustment is applied for fractionation. In one study, low Mw lignin was separated and characterized. The main aim and achievement of this study was to fully understand low Mw lignin’ antioxidant properties which can have very demanding applications in many different materials. Moreover, lignin-silica hybrid materials was developed with the purpose of dye adsorption. In this work it was clearly observed that low Mw lignin gives better reaction and creates more network which adsorbs dye efficiently. Recently, lignin based shear-thinning hydrogels were developed for the antibacterial applications. It was observed that, how modification of lignin including lignin-nanoparticles as well as amination of lignin can enhance its antibacterial properties substantially.
Key words: LignoBoost lignin, Clean Flow Black lignin, Low Mw lignin, fractionations, modifications, antioxidant activity, sorbent, antibacterial properties
2: Nanowood – Improving Wood Properties for Nanocellulose Production
Author(s): Anne Bünder, Totte Niittylä
Corresponding author: Totte Niittylä
Affiliation: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umeå, Sweden
Wood is an abundant and renewable source of cellulose. Confronting a steady decline of fossil fuels, environmental pollution and climate change, its importance will increase in the future as the demand for renewable material, chemicals and fuels increases. Wood from trees can be used as the raw material for nanocellulose. Cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) are used in new innovative biobased nanomaterials including novel composition, absorbents or membranes and a spectrum of new medical applications. The Nanowood project aims to bring fundamental wood biology and material science together by focusing on nanocellulose production from wood. Currently, the use of modern tree breeding tools to improve the suitability and efficiency of wood for nanocellulose production is unexplored. In this project we aim to identify underlying genetic factors controlling cellulose biosynthesis, cellulose microfibril dimensions and crystallinity as well as factors that facilitate nanocellulose extractability from wood. The focus is on spruce as the economically most important tree in Sweden, and hybrid aspen as a fast-growing feedstock envisioned for the Swedish plantation forestry.
Key words: Cellulose, Cellulose biosynthesis, Nanocellulose, Cellulose Nanocrystals, Wood
3: The accuracy of genomic selection and benefits of clonal forestry in Swedish Norway spruce
Author(s): Zhiqiang Chen 1, John Baison 1, Jin Pan 1, Bo Karlsson 2, Bengt Andersson Gull 2, Johan Westin 2, María Rosario García Gil 1, Harry X. Wu 1
Corresponding author: Harry X. Wu
Affiliation: 1 Swedish University of Agricultural Sciences (SLU); 2 Forestry Research Institute of Sweden (Skogforsk)
Genomic selection (GS) using high-dense genomic makers has been successfully incorporated into livestock breeding programs to shorten the breeding cycle and improve the accuracy of breeding value prediction. In commercial tree species, evaluation of accuracy for genetic parameters and genetic gain using GS has been started in recent years.
Norway spruce is the number one commercially important tree species in Sweden. Compared to the conventional phenotypic selection, genetic parameters and breeding values prediction are more accurate and genetic gain could be doubled per unit time through GS. In the future, forestry company such as SweTree Technologies and Stora Enso could use genomic-based breeding values instead of breeding values estimated from phenotypic values to select the best trees for next generation breeding or clonal propagation. However, evaluation of GS in Norway spruce clonal selection has not yet been done. Thus, the aims of my project are to 1) evaluate the accuracy of GS for growth and wood quality traits in Norway spruce; 2) evaluate the importance of dominance, epitasis, and genotype-by-environment (GxE) interaction using GS in Norway spruce breeding; and 3) evaluate genetic gain of clonal forestry in Norway spruce using GS and phenotypic selection.
After we studied the details of benefits from GS in breeding and clonal selection, we could incorporate GS into breeding program and clonal forestry that will fundamentally accelerate the breeding of Norway spruce, shorten the breeding cycle, and improve genetic gain.
Key words: Genomic selection, Norway spruce, clonal forestry, GxE interaction, Dominance
4: Hierarchical chirality of cellulose nanomaterials
Author(s): Kevin Conley, M.A. Whitehead, Theo van de Ven, Tapio Ala‐Nissilä, Martti Puska
Corresponding author: Kevin Conley
Affiliation: Aalto University
Cellulose, the basic building block and structural element of trees and plants, has a hierarchical chirality observed at many levels of cellulosic materials. Twisting is observed from the macroscopic spiral grain in the trunks of trees to the left-handed helical orientation of fibers and microfibrils within the cell wall and in highly crystalline cellulose fibrils.
We prove both experimentally and theoretically that the twisting of cellulose nanocrystals about their chain axis is not due to the intrinsic chirality of the chains comprising the crystal, but rather the complex interactions between these chains. Not only does the frequency of the twist depend on the width of the crystals, but the handedness reverses in very thin nanocrystals.
These findings give a detailed understanding of the changes in the crystals and fibrils during manufacturing and offer unprecedented control of the surface interactions, enabling the design of new applications of cellulosic nanomaterials. The chiral inter‐crystal interactions dictate the properties of the chiroptical films and suspensions, which can potentially act as chiral inducers and separators or as scaffolds for anisotropic metal nanoparticles with unique optical properties. Furthermore the twisting of the nanocrystals provides a mechanism of the twists to propagate across cellulose materials.
Key words: Hierarchical structure, cellulose twist, chirality, time dependent density functional theory
5: Fungal auxin and its role during ectomycorrhiza formation between Laccaria bicolor and tree root tips
Author(s): Yohann Daguerre 1, Aleš Pěnčík 2, Ondej Novak 2, Roger Granbom 1, Karin Ljung 1, Minna Kemppainen 3, Alejandro Pardo 3, Uwe Sauer 4, Judith Felten 1
Corresponding author: Yohann Daguerre
Affiliation: 1 Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, 901 83 Umea, Sweden; 2 Laboratory of Growth Regulators, Centre of the Region Haná for Biotechnological and Agricultural Research, Institute of Experimental Botany AS CR & Faculty of Science of Palacký University, Šlechtitelů 27, CZ-78371 Olomouc, Czech Republic; 3 Laboratorio de Micología Molecular, Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bernal, Argentina; 4 Department of Chemistry, Umeå University, 901 87 Umeå, Sweden.
Ectomycorrhizal (ECM) symbiosis are mutualistic interactions occurring between tree root tips and soil fungi. ECM symbiosis are essential for forest ecosystems and promote tree growth. In exchange for sugars from plants, fungi transfer nitrogen and phosphorous to the tree, which are nutrients often limited in forest soils.
Currently we are focusing on revealing the molecular mechanisms of ECM formation between Laccaria bicolor and poplar trees. During the colonization process, fungal hyphae surround the root tips to form a mantle. Subsequently, hyphae penetrate between the root cells to form a nutrient exchange structure, called Hartig net, which requires cell wall remodeling in both partners. Auxin, a phytohormone secreted by the fungus has been hypothesized to favor this process through cell wall loosening. In order to better understand the role of fungal auxin for Hartig net formation, we are studying in silico identified genes involved in both auxin biosynthesis and release pathways in L. bicolor. Ultimately, functional analysis of mutant strains will be performed to uncover the role of fungal auxin for ECM formation.
Increase the understanding of molecular mechanisms underlying ECM development is the first step toward a better use of ECM fungi to promote forest productivity and decrease chemical fertilizations.
Key words: Ectomycorrhiza, Fugal auxin, Hartig net, cell wall remodeling
6: Discovering genetic markers for superior Populus tree biomass as a source of bioproducts
Author(s): Sacha Escamez, Madhavi Latha Gandla, Niklas Mähler, Kathryn Robinson, Leif J. Jönsson, Nathaniel Street and Hannele Tuominen
Corresponding author: Hannele Tuominen
Affiliation: Department of Plant Physiology, Umeå University, Umeå Plant Science Centre (UPSC), SE-901 87 Umeå, Sweden.
E‐mail: First author: firstname.lastname@example.org; Corresponding author: email@example.com
Shifting towards a sustainable economy involves refining wood biomass into building blocks for bioproducts and clean energy. The fast growing Populus species represent a promissing source of wood biomass but their potential remains underexploited. The main problem is the recalcitrance of wood biomass when trying to separate its individual components that serve as a basis for different bioproducts. Recently, we showed that specific aspects of wood chemical composition and structure could predict glucose yield, one of the most valuable products of biomass deconstruction (Escamez et al., 2017; https://www.nature.com/articles/s41598-017-16013-0). Now, we are repeating similar analyses of wood chemical composition and structure in relation to deconstruction yield in a collection of 113 Populus clones from all over Sweden known as the SwAsp collection. Furthermore, we take advantage of the known genome sequences of these 113 SwAsp trees to identify mutations associated with the wood traits that predict the yields of glucose and other biomass deconstruction products. Through such Genome-Wide Association Study (GWAS) we have already identified a new gene related to lignin composition in wood, which is a predictor of yield. Our work will therefore reveal genetic markers enabling to exploit the full potential of Populus tress as bioproducts crops.
Key words: Genetic markers, Wood, Biomass, Populus, Glucose, Lignin
7: Towards the purposeful cellulose conversion
Author(s): Svitlana Filonenko, Markus Antonietti
Corresponding author: Svitlana Filonenko
Affiliation: Max Planck Institute of Colloids and Interfaces
Regarding the maintained tendency of modern society to decline petroleum resources, development of economically and energy efficient processes for cellulose conversion for the sustainable production of fuels and chemicals attract tremendous attention. Foremost cellulose is the only current sustainable source of organic carbon and liquid biofuels, which generate much less greenhouse gas emission than do fossil fuels. But high complexity of cellulose requires additional process steps for it treatment which increases the price of the products. Thus cost-efficient technologies for processing cellulose are yet to be commercially developed.
Important research in this area includes utilization of deep eutectic solvents (DES) for cellulose treatment. DES may also have an ionic character and thus considered to be an alternative to ionic liquids, but with much lower toxicity, easy to prepare and their individual components are less expensive. Additionally DES are often biodegradable and foreseen as the next generation green solvents. In the cellulose treatment DES can play a crucial role as they can be defined not only as the reaction media, but also as reagent and/or catalyst. This can drastically increase the efficiency of cellulose treatment processes and make it more aimed at targeted products. Our work is aimed to reveal the features of DES governed by their composition and influence of those features on the functional properties of DES. Particularly inclusion of ammonium formate as the component of DES provides it with unique properties including low viscosity combined with the broad potential window. In this composition ammonium formate can also act as sacrificial amination reagent for the products of carbohydrate biomass hydrolysis.
Key words: Deep eutectic solvents, cellulose transformation, ammonium formate, biomass hydrolysis
8: Allocation of conservation measures in a production boreal forest while balancing the scales of ecosystem services and biodiversity
Author(s): Anna Filyushkina, Eva‐Maria Nordström, Lina A. Widenfalk & Thomas Ranius
Corresponding author: Anna Filyushkina
Affiliation: Swedish University of Agricultural Sciences
This study aims to assess the effects of spatial allocation and size of conservation measures on provision of ecosystem services and preservation of biodiversity in a production boreal forest. By conservation measures we understand either unmanaged areas of the following sizes: groups of retention trees, set asides (less than 50ha each) and nature reserves (100 ha each); or extended rotation age. Since it is difficult to get a complete picture using only empirical studies, we combined scenario simulations with an expert assessment method – the Delphi technique. Using data from a production forest landscape of 15000ha in central Sweden we constructed seven scenarios with the same total level of conservation efforts in each (16% of area). The scenarios differed in proportions of conservation measures and their distribution in landscape. We then used the Delphi technique to inquire experts (researchers in relevant fields) regarding capacity of these scenarios to provide ecosystem services and preserve biodiversity. The Delphi technique implies several rounds of deliberations, in which experts fill out inquiries individually and anonymously. In second round, experts were provided with an opportunity to revise their answers (if they deemed it appropriate) based on provided summaries of answers and comments from everyone in their panel. The findings provide insight on how levels of provision of services and biodiversity might change with various patterns of allocation of unmanaged areas in forests. Next steps include inquiring stakeholders regarding relative importance of values they see in these scenarios and conducting a multi‐criteria assessment combining stakeholder values with expert judgements.
Key words: Forest management, unmanaged forests, extended rotation, ecosystem services, biodiversity, trade‐offs and synergies
9: Understanding moisture uptake in wood for durable and sustainable wood structures
Author(s): Maria Fredriksson, Emil Engelund Thybring, Lisbeth Garbrecht Thygesen
Corresponding author: Maria Fredriksson
Affiliation: Building Materials, Lund University, Lund, Sweden
The construction sector is responsible for a substantial part of carbon dioxide emissions in Sweden and globally. An increased use of wood as construction material could decrease these emissions, but the replacement of other construction materials with wood‐based materials is presently limited by wood’s susceptibility to fungal degradation. Alternatives to impregnation with biocides are needed due to environmental and health issues. Chemical modification, e.g. acetylation is such an alternative, but the exact mechanisms behind the increased durability are not known, except that it is related to the reduced moisture content of the modified wood. However, the fungi’s ability to degrade the wood is not simply determined by the amount of water in the wood, the location and state of the water within the wood structure are also important but less studied factors. In this project, we study the amount, location and state of water in wood, including the influence of modification, using a combination of methods and with focus on high relative humidity levels relevant for fungal degradation. A better understanding of moisture uptake in untreated as well as chemically modified wood could increase the understanding of the mechanisms behind the increased durability of chemically modified wood. In the long‐term, this knowledge would enable optimized wood modification techniques to make cost‐effective wood products with enhanced durability and potential to replace construction materials with higher climate impact.
Key words: Durability, moisture, modification, sorption, water, wood
10: Identification and characterization of novel amino acid transporter in hybrid aspen
Author(s): Regina Gratz, Ulrika Ganeteg, Iftikhar Ahmad, Sandra Jämtgård, Henrik Svennerstam, Jonathan Love, Mattias Holmlund and Torgny Näsholm
Corresponding author: Regina Gratz
Affiliation: Swedish University of Agricultural Sciences (SLU), Umeå
Excessive nitrogen (N) fertilization has negative effects on e.g. human health, the environment and climate. A detailed understanding of all aspects of N nutrition is required to minimize these effects. Current advances in soil biogeochemistry demonstrated that the contribution of amino acids (AAs) to forest soil N fluxes is higher than previously thought, suggesting that AA transporters are key components of plant N nutrition in these settings.
Here we present novel findings on hybrid aspen (Populus tremula L. x tremuloides Michx) AA transporters. Gene expression studies showed that eight homologs of the Arabidopsis AA transporter lysine histidine transporter 1, AtLHT1, were expressed in different tissues such as roots, stem and leaves. Heterologous expression of the closest homolog, PtrLHT1.2 in an AtLHT1 mutant, rescued both the root‐uptake and the early senescence‐like phenotypes caused by the mutation. PtrLHT1.2 showed similar AA affinity spectrum to AtLHT1, with high affinity for L‐Gln and low affinity for L‐Arg, suggesting the identification of a functional ortholog of AtLHT1. The potential influence of plant amino acid uptake on the soil microbial community at the root‐soil interface is currently investigated.
This work may contribute to the development of tools reducing N fertilization without affecting productivity in agricultural and forest ecosystems.
Key words: Amino acid based nitrogen nutrition, Forest soils, Amino acid transporter
11: Toward continuous cover forestry on boreal lowlands – Hydrological responses to partial harvesting
Author(s): Kersti Haahti (1); Samuli Launiainen (1); Annalea Lohila (2); Mika Korkiakoski (2); Raija Laiho (1); Raisa Mäkipää (1); Mika Nieminen (1)
Corresponding author: Kersti Haahti
Affiliation: (1) Natural Resources Institute Finland; (2) Finnish Meteorological Institute
Interest towards continuous cover forestry (CCF) has grown in recent years as it is considered more favorable from environmental perspectives than even‐aged management. CCF could be particularly feasible on peatlands and other lowland soils as continuously maintaining a tree cover with significant evapotranspiration capacity could decrease the need for artificial drainage. Clear cutting, site preparation, and regular cleaning of drainage ditches increase greenhouse gas emissions and affect water quality by releasing sediment, nutrients and carbon to water bodies. Whereas even‐aged management on peatlands relies on these intensive and
environmentally adverse practices, regeneration in CCF forests would occur naturally and evapotranspiration of the tree stand would play a key role in maintaining drainage conditions. Partial harvest is an essential component of CCF and our study focuses on understanding its impacts on hydrology. The study site comprises a fertile drained peatland forest in Southern Finland, where three parallel sites were established in March 2016: clear‐cut, partial harvest, and control. Data on ecosystem fluxes (Eddy covariance) and ground water depth were available from each site after the harvest and for a pre‐treatment period of 6 years. In our attempt to understand the mechanisms behind observed changes after clear‐cut and partial harvest, we applied a multi‐layer multi‐species soil‐vegetation‐atmosphere transfer model in conjunction with data analysis. The hydrology of each parallel site was simulated to explore how the amount and diversity of vegetation affects ground water depth during growing season, a key factor for successful implementation of CCF in peatland forests.
Key words: ground water depth, hydrological modeling, peatland forestry, drainage, silviculture, evapotranspiration, Eddy covariance
12: Upcycling of textile waste
Author(s): Simone Haslinger, Yingfeng Wang, Michael Hummel, Herbert Sixta
Corresponding author: Simone Haslinger
Affiliation: Aalto University
Recently, the global textile production reached 96 million tons demonstrating that the textile industry belongs to the segment of high‐volume products. The dominating natural fiber on this market is cotton. However, the area of arable land per head has almost cut into half over a period of only fifty years, implying that all natural fibers will compete for acreage with food and biofuels in the future. An increasing demand for natural textiles can thus only be satisfied by additional production capacities of man‐made cellulose fibers (MMCFs). This also represents an opportunity for the Ioncell‐F process, a Lyocell‐type fiber process, which uses a super‐base based ionic liquid instead of NMMO. The former does not require any stabilizers and allows processing temperatures 30°C lower than in the Lyocell process. Besides energy savings, and safer processing conditions, the Ioncell‐F process enables the dissolution and regeneration of waste material while avoiding the generation of additional waste streams. Contrary to paper industry, no viable recycling strategies exist for textile industry because of the heterogeneity of most textile products. Therefore, we studied the recyclability of cellulose rich textile waste, blends and mono‐materials, to new MMCFs using the Ioncell‐F process. Moreover, this study aims to give an intelligible overview over material properties, pretreatments, and final processing conditions.
Key words: cellulose, textile waste recycling, cotton, viscose, synthetic fibers, Ioncell
13: Quantitative genetics of lodgepole pine (Pinus contorta) wood quality traits in Sweden
Author(s): Haleh Hayatgheibi, Anders Fries, Johan Kroon, Harry X. Wu
Corresponding author: Harry Wu
Affiliation: Umeå Plant Science center
Stem breakage and general instability of lodgepole pine has been a major problem in northern Sweden due to low stem stiffness. To evaluate the potential incorporation of wood quality traits into lodgepole pine breeding programs, 823 increment-cores were sampled from 207 half-sib families and genetic variations in different wood properties were characterised. To quantify genotype by environment interactions for growth and stiffness, diameter at breast height (DBH) and dynamic stiffness of standing trees (MOEtof) were studied. To evaluate genetic gains in selection for an early microfibril angle (MFA) transition from juvenile to mature wood, six different regression functions were fitted to the MFA profile of each tree.
Narrow-sense heritability estimates ranged from 0.10 to 0.76 for DBH and wood traits. Unfavourable genetic correlations between growth and stiffness implied that selection for a 1% increase in DBH alone, would confer about 5.5% decrease in lodgepole pine stiffness.
Results indicate that simultaneous improvement of DBH and stiffness is achievable when an optimal selection index combining both traits is implemented. Additionally, it is possible to select for an earlier MFA transition from juvenile to mature wood, and thus, decreasing the proportion of the log containing juvenile wood in lodgepole pine selective breeding programs.
Key words: Wood quality traits, genetic parameters, index selection, microfibril angle (MFA), SilviScan, transition wood
14: Foam‐formed fibre materials ‐ challenging plastics
Author(s): Annika E. Ketola, Tuomo Hjelt, Timo Lappalainen, Heikki Pajari, Kristian Salminen, Tekla Tammelin and Jukka A. Ketoja
Corresponding author: Annika Ketola
Affiliation: VTT Technical Research Centre of Finland Ldt
There is an urgent need for environmentally friendly alternatives for plastics in order to avoid increasing amounts of waste in the environment. Foam forming technology enables the production of versatile cellulose fibre materials extending from thick, porous and lightweight structures to stiff 3D forms, thin nonwovens and layered hybrid products. These biodegradable materials challenge the excessive use of plastics in many market sectors such as packaging, cushioning, commodity products and textiles. The interaction between wet foam and fibres plays a key role in achieving desired material performance. The stability and bubble structure of the foam provide tools to tailor the density and pore size distribution of the formed fibre network. Additional effects come from surfactant chemistry and fibre surface properties. Such features are still largely unexplored and their contributions to the final material properties are not clear. We approach this problem by using model systems with gradually increasing complexity. This includes determining the interaction between an air bubble and model cellulose and silica surfaces in surfactant solutions, with parallel characterization of surfactant adsorption using quartz crystal microbalance. The findings are further tested in macroscopic laboratory forming studies, opening ultimately ways to enter new markets with novel foam‐formed products.
Key words: Foam forming, cellulose fibers, fibre‐based materials, light‐weight, environmental friendly, packaging, foamfibre interactions, material tailoring, air bubbles, model surfaces, bubble contact angle, Quartz Crystal Microbalance
15: Is forest more than trees? Effect of moss cover in boreal landscape water and energy cycles
Author(s): Antti‐Jussi Kieloaho and Samuli Launiainen
Corresponding author: Antti‐Jussi Kieloaho
Affiliation: Natural Resources Institute Finland
In boreal and arctic ecosystems, mosses and lichens are ubiquitous component of plant communities both upland forests and peatlands. Moss cover is a biologically active boundary between the atmosphere and soil having an important influence on the nutrient, carbon and water cycling as well as on the energy balance of land surface. Along environmental gradients in a landscape, species composition of moss cover changes having an effect on the ground cover properties.
Although the importance of moss cover as biogeochemically active boundary is widely recognized, mechanisms and effects of the moss cover at ecosystem and landscape level are not well understood. The aim of this work is to fill this knowledge gap by combining empirical datasets through the theoretical framework provided by process‐based modelling.
We study effect of moss cover on forest microclimate and soil hydrology by using two modelling approaches differing in a level of detail and spatial scale. Both models describe the biophysical interactions between soil, moss cover, forest canopy, and the atmosphere.
The first approach simulates a forest stand where the moss cover is described in a detail as a layer in a multilayer multispecies soil‐vegetation‐atmosphere transfer model. The results are applied in the second approach where heterogenous moss cover is introduced into a landscape level process‐based spatial forest hydrology model. The models are tested against measurement data from various ecosystems in boreal and arctic regions.
Key words: Bryophytes, ecosystem modelling, hydrology, biogeochemistry, forest stand, landscape, biosphereatmosphere interactions
16: Mild-alkaline extracted spruce lignin as a plant growth regulator
Author(s): Ekaterina Korotkova, Andrey Pranovich, Elena Ozhimkova, Stefan Willför
Corresponding author: Ekaterina Korotkova
Affiliation: Åbo Akademi University, Finland
Wood is one of the most important natural resources on our planet. Nowadays the problem of complex utilization and efficient use of all wood components is very important. My work focuses on the spruce wood biorefinery process where first hemicelluloses are isolated with pressurised hot water, after that lignin isolation is done as a next step using low concentration alkali solution. Due to ecological and economical aspects, the use of sulfur-free lignin is of increasing interest. By adjusting the isolation conditions, we can fine-tune the properties of our lignin, for example molar mass or hydroxyl groups content. The aim of my research is to assess the effectiveness of different mild-alkaline extracted lignins as plant growth regulators. It was shown that our lignin in low concentrations promotes the germination of flax seeds as well as early seedling development. The need for sustainable farming practices and the limited resources such as land and water, to meet the growing food requirements are projected to enhance the demand for growth regulators. Key to the sustainable future is developing of green techniques with minimal environmental impact. I believe that my work is a step in the right direction.
Key words: Lignin, biorefinery, plant growth regulators
17: An “ideal lignin” facilitates full biomass utilization
Author(s): Yanding Li 1,2, Li Shuai 1, Hoon Kim 1,2, Ali Hussain Motagamwala 1,2, Justin K. Mobley 1, Fengxia Yue 1, Yuki Tobimatsu 3, Daphna Havkin-Frenkel 4, Fang Chen 5, 6, Richard A. Dixon 5, 6, Jeremy S. Luterbacher 7, James A. Dumesic 1,2, John Ralph 1,2
Corresponding author: John Ralph
Affiliation: 1 DOE Great Lakes Bioenergy Research Center, USA; 2 University of Wisconsin-Madison, USA; 3 Kyoto University, Japan; 4 Bakto Flavors, USA; 5 University of North Texas, USA; 6 Center of Bioenergy Innovation, Oak Ridge National Laboratory, USA; 7 École Polytechnique Fédérale de Lausanne, Switzerland.
Lignin, one of the major components of lignocellulosic biomass, is crucial to plant growth and development, but is a major impediment to efficient biomass utilization in various processes. Valorizing lignin is increasingly realized as being essential for sustainably and profitably converting biomass into valuable products. Based on the plethora of information stemming from the lignin biosynthetic research community over the last decade, and with the revelations regarding lignins’ structural malleability from studies on lignin pathway mutants and transgenics as well as on various ‘natural’ plants discovered to possess unusual lignins, researchers are now able to contemplate what constitutes an ‘ideal lignin’ for processing and conversion. The recently discovered catechyl lignin (C-lignin), which is essentially a benzodioxane homopolymer, might represent such an ideal lignin for lignin valorization. Here we discovered that C-lignin is highly acid-resistant that could potentially overcome biomass fractionation issues. Catalytic hydrogenolysis of C-lignin resulted in the cleavage of all benzodioxane structures to cleanly produce catechyl-type monomers in near-quantitative yield, and catalyst selection allows a single monomer to be produced at the 90% level.
Key words: C-lignin, benzodioxane, hydrogenolysis, monomer
18: Two decades of soil warming does not increase boreal forest biomass accumulation
Author(s): Hyungwoo Lim, Ram Oren, Torgny Näsholm, Monika Strömgren, Tomas Lundmark, Sune Linder
Corresponding author: Hyungwoo Lim
Affiliation: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
Increased soil organic matter decomposition with increasing temperature has been hypothesized to enhance soil nitrogen availability, consequently stimulating forest biomass production and offsetting decompositioninduced soil carbon losses. This projection, however, is based on evidence gathered from short‐term studies (≤ 10 years). The key question for carbon sequestration is whether such responses are transient or persist over long forest rotation periods. Here we report on biomass production in a typical nitrogen‐limited boreal Picea abies forest, exposed to 18 years of soil warming manipulation (+ 5 °C) at a plot‐scale (100 m2), the only study of such scale and duration in boreal forests. We show that two decades of soil warming elicited only short duration growth responses, thus not significantly increasing woody biomass accumulation. Furthermore, in combination with published work, our results suggest that (i) increased decomposition in this forest is slight and ephemeral, (ii) tree uptake of nitrogen under warming shifts to deeper soil, and (iii) increased fine root biomass, production, and turnover in deeper soil may be greater than increased decomposition, perhaps conserving the soil carbon stock. Thus, this long‐term study does not support the notion that the projected increase in soil temperatures will cause either an increased carbon loss with decomposition or a compensatory growth increase from nitrogen mineralization.
Key words: carbon, climate change, net primary production, nitrogen, Norway spruce, Picea abies, soil temperature, δ15N
19: Stabilising Glucomannan using Sodium Dithionite
Author(s): Pär Lindén, Mikael Lindström, Martin Lawoko, Gunnar Henriksson
Corresponding author: Pär Lindén
Affiliation: Wallenberg Wood Science Center ‐ KTH
The Kraft process is the dominant method for producing chemical pulp, and while it is an excellent process, one drawback is that part of the carbohydrate content is degraded due to the high amounts of alkali used.
This degradation can be prevented by chemical modification of the carbohydrates. Anthraquinone has been used in the industry for this very purpose but is facing potential legislation after it was discovered that precursors in its manufacture are carcinogenic.
Preferably, a replacement for anthraquinone should be of low cost, not include any non‐process elements and be a reductant. One such candidate is sodium dithionite. However, sodium dithionite was investigated in the 1950s and determined to be unviable as an additive to the Kraft process under normal pulping conditions.
This project investigated if sodium dithionite could be viable using different process parameters. It was discovered that alkalinity is crucial to the process: if pH is too high or too low no reduction was observed. From a centre point of pH 8 and 85 °C, an optimum for the reduction of monosaccharides was found at pH 10 and 70 °C. This indicates that dithionite is stabilised at higher alkalinities but that high alkalinity also promotes degradation of carbohydrates. That degradation can, however, be mitigated by using a lower temperature.
Key words: sodium dithionite, reductive reaction, peeling reaction, glucomannan
20: Phase‐change transparent wood composites for thermal energy storage
Author(s): Céline Montanari, Yuanyuan Li, Lars Berglund
Corresponding author: Céline Montanari
Affiliation: Wallenberg wood science center, Kth Royal Intitule of Technology, Stockholm, Sweden
With the increase of greenhouse gas emissions due to high energy consumption and production, green renewable energies and technologies directed towards energy savings have been developed. Phase‐change materials (PCMs) are examples of energy storage technologies used in the building area to decrease heat energy loss. PCM, such as salt hydrates and organics, can store and release latent heat energy during a reversible phase change process. Polyethylene glycol (PEG) is an environmental friendly and recyclable organic PCM, which exhibits large latent heat and solid‐liquid phase change at suitable temperature range. However, the utilization of solid‐liquid PCMs such as PEG is limited by leakage issues occurring during the phase change, hence negatively affecting their long‐term thermal reliability. In this study, the wood structure is used to encapsulate PEG to prevent leakage during phase transitions. Phase‐change transparent wood (PCTW) composites are prepared via a two‐step procedure, which includes delignification followed by vacuum‐impregnation of the delignified wood template with a PEG/PMMA polymer blend. PCTW composites exhibit a combination of excellent thermal properties – with latent heat around 75 J/g – and optical transparency. PCTW showed good mechanical performance with a tensile strength of 70 MPa and stiffness of 15 GPa. The multi‐functional PCTW composites can be used as a load‐bearing material to regulate indoor/outdoor temperature variations; extending the applications of transparent wood to energy‐saving buildings.
Key words: Biocomposite, transparent wood, phase‐change material, energy storage
21: Biochar as a tool to mitigate the effects of climate change: The role of soil microorganisms
Author(s): Melissa R.A. Pingree, Michael J. Gundale
Corresponding author: Melissa R.A. Pingree
Affiliation: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
Biochar management in boreal forest soils may maximize carbon (C) storage above and belowground and thus offset increasing concentration of CO2 in the atmosphere, yet uncertainties remain regarding how soil microorganisms utilize this novel material. Previous research suggests that biochar in agriculture soils influences the surrounding soil, or ‘charosphere’, of biochar particles, rather than providing habitat and refuge for soil organisms. In a large-scale experiment in northern Sweden, we evaluate the intermediate-term effects (6-8 years) of biochar management on C and nitrogen (N) cycling and microbial activity and community. This experiment allows unique comparisons of microbial communities in biochar surfaces and that of the immediately surrounding soil, or ‘charosphere’, in order to connect mechanisms of nutrient cycling to soil and biochar properties. We will conduct soil nutrient and microbial analyses on unperturbed soil cores collected from field sites and preserved for dissection. The surfaces of biochar fragments, charosphere soil, and soil at least 5 cm from biochar particles will be analyzed for nutrient concentrations, mineralization rates, microbial biomass, and microbial community composition. Biochar as a tool to store C, enhance plant productivity, and retain nutrients may be ineffective without a clear understanding of microbially-mediated processes in boreal forest soils.
Keywords: biochar management; boreal forest; carbon sequestration; charcoal; nitrogen mineralization; nutrients; soil carbon efflux; pyrogenic carbon
22: Lignin Bimodality – Fact or Artefact?
Author(s): Sofia Regnell Andersson, Jerk Rönnols, Fredrik Aldaeus, Anna Jacobs
Corresponding author: Sofia Regnell Andersson
Affiliation: RISE Innventia
Lignin has long been considered a waste material from the chemical pulping process but has a lot of potential as an abundant source of polymeric raw material which can be transformed into high value chemicals, for example liquid fuel and phenolic chemicals. To achieve this, a clear understanding of the polymeric structure and how it is changed with different treatments is crucial. One of the key parameters governing the properties of lignin is its molar mass, and Size Exclusion Chromatography (SEC) is by far the most common method for molar mass determinations.
In numerous studies, SEC chromatograms of lignin show a bimodal peak, indicating a non‐gaussian molar mass distribution. Many conclusions about lignin’s properties have been drawn based on this information. This study shows that the bimodality in the chromatograms is not necessarily a true characteristic of lignin but more likely an artefact from using combinations of chromatographic columns that do not match properly. Incorrect conclusions regarding degradation behaviour or occurrence of side reactions have been drawn from this artefactually observed bimodality, leading researchers astray. The vision of this work is to make the community aware of this misinterpretation and thereby enable lignin to contribute in achieving a circular economy.
Key words: Lignin, Size Exclusion Chromatography (SEC)
23: Printed Power Paper Energy Storage Devices
Author(s): Mehmet Girayhan Say, Robert Brooke, Jesper Edberg, Isak Engquist, Magnus Berggren
Corresponding author: Mehmet Girayhan Say
Affiliation: Linköping University
The need for green energy harvesting also brings great attention to green energy storage devices, where paper based storage devices have found environmentally friendly device applications. Nanofibrillated cellulose is an outstanding polymer due to its extraordinary mechanical properties, large surface area, biocompatibility and capability to provide porosity to electrode materials. The combination of conductive and nanofibrillated cellulose results in paper electrodes with high ionic and electronic conductivity, quick charge capability and mechanical durability. This combination allows us to fabricate supercapacitors, which are next‐generation energy storage devices, where quick charge and high volume of charge storage are desired for many low power electronics applications.
Printed electronic tools and techniques are very efficient for preparing paper supercapacitors on various large area substrates in order to interface flexible hybrid electronics. Our research is focused on using cellulose and its derivatives in electrode and electrolyte systems to fabricate all solid state, roll‐to‐roll compatible, large area and high power paper supercapacitors. Combining these technologies with cellulose‐based materials will bring low cost, light weight and roll‐to‐roll fabricated energy storage devices that will open pathways for smart industry 4.0.
Key words: Conductive Polymer, nanofibrillated cellulose, energy storage devices
24: Carbonaceous materials production from kraft lignin
Author(s): Ekaterina Sermyagina, Sara‐Maaria Alatalo, Kirill Murashko, Esa Vakkilainen
Corresponding author: Ekaterina Sermyagina
Affiliation: Lappeenranta University of Technology
Lignin is widely abundant aromatic polymer which reinforces the cellulose fibres in plants. Besides few marginal applications, the vast majority of lignin obtained in the paper industry is currently consumed as a fuel on‐site. At the same time, a high carbon content and a molecular structure similar to the low‐rank coals make lignin highly potential precursor for the production of the activated carbons.
Hydrothermal carbonization offers a promising possibility to accelerate the natural process of coalification and produce a valuable carbon‐rich material (hydrochar). As a rule, hydrochar has limited porosity and the subsequent activation procedure is needed to obtain the required properties. There are certain challenges which need to be considered: high thermal stability and low reactivity of lignin in comparison with other lignocellulosic components.
In our research, we would like to address the issues of porosity development and its possible tuning during carbonization step. The lignin‐based activated carbons will be used for supercapacitors’ electrodes manufacturing. The effect of different catalyzers (both acidic and salt‐water mixtures) on structural and morphological properties of materials as well as the electrochemical characteristics of supercapacitors will be investigated. Better understanding of the nature of such treatment will expand currently limited use of lignin and bring valuable benefits to the industry and society.
Key words: Lignin, Hydrothermal carbonization, Chemical activation, Electrochemical energy storage
25: Sonication‐assisted surface modification method to expedite the water removal from cellulose nanofibers for use in nanopapers and paper making
Author(s): Jatin Sethi, Kristiina Oksman, Mirja Illikainen and Juho Antti Sirviö
Corresponding author: Juho Antti Sirviö
Affiliation: University of Oulu, Finland
Hereby, we address the issue of high water retention by cellulose nanofibers (CNFs), which leads to inordinate amount of time to drain water from CNF suspensions. This restricts the use of CNF in commercial products such as nanopapers and nanocellulose reinforced paper-sheets. Nanopaper, especially, suffers a lot from this drawback as it has otherwise excellent properties. It is extra strong, with a modulus of 10 GPa, and transparent. Additionally, it has lower coefficient of thermal expansion similar to glass, and yet it is foldable just like paper. This makes it an attractive candidate for functional applications such as printable electronics and flexible displays. As a solution, we suggest an eco-friendly method that uses sonication and lactic acid (LA) to modify the surface of CNFs. The LA modified CNFs produced with this method drained water in 10 minutes, while the reference CNFs took 45 minutes. Additionally, the nanopapers prepare from the LA modified CNFs were mechanically stronger and water resistant. Furthermore, this method gave 56% better results from a common benchmark: addition of salt. Finally, using this method, a 10 wt.-% CNF reinforced paperboard was produced in 2 minutes while unmodified CNFs reinforced paperboard took 23 minutes.
Key words: Dewatering; Cellulose nanofibers; Lactic acid; Surface modification; Nanopapers; Papermaking
26: Decreasing permeability model for moisture content during vacuum dewatering
Author(s): Björn Sjöstrand
Corresponding author: Björn Sjöstrand
Affiliation: Karlstad University
This work is about developing equations, based on previous work by McDonald and Kerekes 1), that will predict dewatering at the vacuum section of the paper machine. With these dewatering equations, it will be possible to suggest improvements for process energy efficiency, and facilitate the introduction of new raw materials in full scale production.
Many fossil‐based materials such as plastics can now be made from forest‐based raw materials, mainly at a laboratory level. The next step in this development is the transition from laboratory scale to full scale production. This needs a lot of experimentation, but experiments in full scale are very expensive and time consuming. Equations describing the dewatering behavior can make the necessary experiments easier. Without disrupting the ongoing production and with the possibility to change and examine several different parameters at the same time, the pace for introducing new materials to existing papermaking processes can be changed.
Introducing renewable and biodegradable materials as an alternative to plastics, is of great importance for the environment. In my opinion, we must develop new sustainable materials that are equally great in performance, equally cheap and at the same time environmentally friendly, to reach true sustainability.
1) Mcdonald, J. D. and Kerekes, R. J. (2017) ‘Estimating Limits of Wet Pressing on Paper Machines’, Tappi Journal, 16(2), pp. 81–87.
Key words: Vacuum dewatering, decreasing permeability model, moisture content, paper manufacturing, paper machine
27: “Carbon isotope methods to connect the carbon and water cycles of forests”
Author(s): Zsofia R. Stangl, Lasse Tarvainen, Mats Räntfors, Göran Wallin, John D. Marshall
Corresponding author: Zsofia R. Stangl
Affiliation: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden
The carbon and the water cycle of trees are intrinsically coupled, and tied to nutrient acquisition and forest growth. The trade‐off between the amount of assimilated carbon and transpired water is described as photosynthetic water‐use efficiency. On a leaf‐level, water‐use efficiency is determined by the ability of CO2 and water vapor to diffuse in and out of the leaf, which ability is determined by the conductance of leaf tissues, at multiple levels of the diffusion pathway. Simultaneous measurements of leaf gas‐exchange, and the discrimination of photosynthesis against 13C, a naturally occurring stable isotope of carbon, can be used to dissect leaf conductance into its components. Recent technical advances in absorption spectroscopy made it possible to perform these measurements under field conditions. We set up a system to continuously monitor shoot‐level gas‐exchange and 13C discrimination in a Scots pine stand and obtain data to describe the diurnal and seasonal patterns of leaf conductance, with the aim to gain a more mechanistic understanding of the connection between the carbon and water cycles of trees, and the influence of variable environmental conditions on their relationship. The broader perspective of our work is to integrate this knowledge into larger scale models of forest growth and carbon sequestration.
Key words: Mesophyll conductance, stomatal conductance, online discrimination, cavity ring‐down absorption spectrometry, vapor pressure deficit
28: Combined production of transportation liquids and heat from biomass residues through gasification
Author(s): Sanna Tuomi, Esa Kurkela, Ilkka Hannula
Corresponding author: Sanna Tuomi
Affiliation: VTT Technical Research Centre of Finland Ltd, P.O. Box 1000, FI‐02044, Espoo, Finland
In the attempt to tackle climate change and reduce emissions in transportation, the EU has just recently announced new binding targets for the transport sector as part of the Renewable Energy Directive RED II. By 2030, renewables should account for 14 % share in transportation and a minimum target of 3.5 % was set for advanced biofuels. Gasification in combination with synthesis technology is recognized as a viable route for producing high‐quality drop‐in transportation liquids from biomass (Biomass‐to‐Liquids, BTL). This process enables efficient utilization of a wide variety of biomass feedstocks, such as side products generated in the forest industry (forest residues, bark etc.). VTT is currently developing a new BTL process that targets at intermediate‐scale (100‐150 MW fuel input) corresponding to 30‐50 ktoe/a production of transportation liquids. The proposed concept combines a steam‐blown dual fluidised‐bed gasifier operated at close to atmospheric pressure with a simplified gas clean‐up train and high‐efficiency Fischer Tropsch synthesis. With this concept, around 50 % of biomass energy content is converted into transportation liquids and 30‐40 % to heat to achieve a total efficiency of more than 80 %. This work provides a summary of the techno‐economic assessments conducted to evaluate the economic viability of the new BTL technology.
Key words: Biomass‐to‐Liquids, biomass gasification, transportation liquids, Fischer Tropsch synthesis
29: Lignin‐based carbon mats – promising electrodes of supercapacitors from wood
Author(s): Jiayuan Wei 1), Shiyu Geng 1), Olli Pitkänen 2), Topias Järvinen 2), Krisztian Kordas 2), Kristiina Oksman 1, 3)
Corresponding author: Jiayuan Wei
Affiliation: 1) Department of Engineering Sciences and Mathematics, Luleå University of Technology, SE-97187 Luleå, Sweden; 2) Microelectronics Research Group, University of Oulu, FI-90570 Oulu, Finland; 3) Fibre and Particle Engineering Research Group, University of Oulu, Finland
Lignin is one of the major renewable sources which can be obtained from the forest, however, about 98% of lignin from pulping and papermaking industry has been wasted or simply burnt. Recent studies show that lignin can be spun and converted to carbon fibers of high quality due to its abundant phenolic structure. Moreover, electrospinning as a state-of-art process can be applied to produced lignin-based nanofiber mats, which gives the fiber mats significantly high specific surface area. Together with carbonization process, the lignin-based carbon mats are attractive to be used as electrodes in supercapacitors for energy saving and storage. In this study, lignin/poly(vinyl alcohol)-based fiber mats with very high lignin content (75 wt%) are prepared via electrospinning and the as-spun mats are carbonized at different temperatures up to 1400 °C. The fiber networks obtained from electrospinning remains intact after the carbonization process, which guarantees their outstanding specific surface areas as high as 1700 m2/g. Furthermore, the electrochemical measurements of the carbonized mats indicate that a superior specific capacitance of 241 F/g are reached compared with most of the literature-reported values, which shows that the lignin-based carbon mats have great potential to replace electrodes from fossil-based and/or unrenewable materials.
Key words: lignin, supercapacitor, electrospinning, carbon, capacitance
30: Hierarchical Assembly of Nanocellulose based Filaments by Interfacial Complexation
Author(s): Kaitao Zhang and Henrikki Liimatainen
Corresponding author: Henrikki Liimatainen
Affiliation: University of Oulu
In the present study, interfacial complexation spinning of oppositely charged cellulose‐materials is applied to fabricate hierarchical and continuous nanocellulose based filaments under aqueous conditions by using cationic cellulose nanocrystals (CCNCs) with different anionic celluloses including soluble sodium carboxymethyl cellulose (CMC) and insoluble TEMPO‐oxidized nanofibers (TO‐CNF) and dicarboxylated cellulose nanocrystals (DC‐CNC). The morphologies of the wet and dry nanocellulose based filaments are further investigated by optical and electron microscopy. All fabricated continuous nanocellulose based filaments display a hierarchical structure similar to the natural cellulose fibers in plant cells. To the best of our knowledge, this is not only the first report about the fabrication of nanocellulose based filaments by interfacial complexation of cationic CNCs with anionic celluloses but also the first demonstration of fabricating continuous fibers directly from oppositely charged nanoparticles by interfacial nanoparticle complexation (INC). This INC approach may provide a new route to design continuous filaments from many other oppositely charged nanoparticles with tailored characteristics.
Key words: cationic nanocellulose, TEMPO‐oxidized nanofiber, filament, interfacial complexation
31: Preparation and characterization of multifunctional nanocomposites based on lignin nanoparticles and nanocellulose from holistic rapid‐formic acid fractionation of bamboo
Author(s): Yongchao Zhang , Qingxi Hou, Xiaoju Wang, Stefan Willför, Chunlin Xu, Menghua Qin
Corresponding author: Yongchao Zhang
Affiliation: Åbo Akademi University
To achieve full utilization of lignocellulosic biomass and easy integration of nanomaterials production, it is essential to develop an efficient fractionation to overcome the highly recalcitrant nature of lignocellulose and facilitate the subsequent valuable conversion. Herein, in a combined process based on the rapid‐formic acid fractionation of bamboo chip, pure cellulose, lignin and hemicelluloses were firstly obtained as fractionated streams. The bamboo‐originated cellulose, as a raw material, was easily converted into cellulose nanocrystals (CNCs) using TEMPO oxidation in a relatively short time in comparison to wood Kraft pulp, which holds greater potential to meet the commercial cost target. The dissolved lignin was processed into nanoparticles (lignin‐NPs), which exhibited sphere morphology and a uniform particle size distribution.
Dispersions of CNCs and lignin‐NPs were prepared and further filtrated to result in nanocomposite membranes. The nanocomposite membranes, in varied compositional ratios of CNCs and lignin‐NP, were elaborately characterized with SEM, TGA, mechanical property and antibacterial activity analysis. Most impressively, at the CNCs/lignin‐NPs ratio of 5, the tensile strength and Young’s modulus were improved by 44% and 47%, respectively, compared to the pure CNCs film, and antimicrobial tests confirmed nanocomposite as effective antibacterial agents against E. coli (ATCC 11229). The direct conversion of the lignocellulose with the combined process drives the integrated biorefinery platform nearer to largecommercial application for cost‐efficient production of wood‐based multifunctional nanomaterials.
Key words: Bamboo chips; Formic acid fractionation; Cellulose nanocrystals; Lignin nanoparticle; Nanocomposite