1. Paper-based supercapacitors

Author(s): Britta Andres
Corresponding author: Britta Andres
Affiliation: Mid Sweden University
E-mail: britta.andres@miun.se
Abstract:
Supercapacitors are high performance energy storage devices that offer many advantages like high power densities, fast charge/discharge times and long lifetimes. Due to high purchase prices the use of supercapacitors is limited. Thus we introduced the concept of low cost paper-based supercapacitors. Paper serves as a carrier for the active electrode material, as ion conductor and as separator in the supercapacitor. Different carbon materials, like graphene, graphite and activated carbon are used as active material for the electrodes. We are developing a process to produce large quantities of inexpensive graphene by mechanical exfoliation of graphite. Both coated and filled electrode papers were prepared and tested in supercapacitors. Besides graphene we coated several graphene/graphite composites on paper. By adding small amounts of gold nanoparticles or nanofibrillated cellulose (NFC) the supercapacitors performance can be improved to a great extent. Specific capacitances of up to 100 F/g for coated paper electrodes and sheet-resistances as low as 0.5 Ω/sq could be obtained. Another advantage of this concept is that papermaking technologies can be used to prepare conducting electrodes, thin separators and manufacture the device itself. The paper industry has the ability to facilitate a large scale production of inexpensive supercapacitors.
Key words: supercapacitor, paper, graphene, graphite

2. New method for the extraction of lignin from kraft black liquor

Author(s): Anders Arkell, Johanna Olsson
Corresponding author: Anders Arkell
Affiliation: Lund University / SunMembrane AB
E-mail: anders.arkell@chemeng.lth.se
Abstract:
I am at the moment working with the development of a new method, based on membrane filtration, for the extraction of lignin from kraft black liquor. This method has the advantage, compared to the technology used today, that the negative impact on the pulp mill is negligible, no chemicals are added to the black liquor and the sodium sulphur balance in the pulp mill is not impaired. This process has two configurations. By the use of the first one, a green gasoline is produced. The second configuration (patent pending) allows production of a solid lignin. This solid lignin can be used as a solid fuel either internally in the pulp mill or externally, or be sold as a raw material for other products.
The plan is to start up a pilot plant for the production of a solid lignin next year. The production in this scale will be approximately 500 kg of solid lignin per day.
This process does not only produce a valuable by-product for the pulp mill but do also decrease the load on the recovery boiler leading to an overall increased productivity for the pulp mill.
Key words: Kraft black liquor, Lignin, Separation process, Green chemicals, Membrane filtration

3. Evaluation of the Thermal and Structural Performance of Innovated Potential Energy Efficient Wall Systems for Mid-Rise Wood-Frame Buildings

Authors: Hadia Awad, Mustafa Gul, Hamid Zaman, Haitao Yu, Mohamed Al-Hussein, Ahmad Al-Rifai
Corresponding author: Mustafa Gul
Affiliation: Univ. of Alberta, Dept. of Civil & Env. Eng
E-mail: mustafa.gul@ualberta.ca
Abstract:
Worldwide, there is a trend toward the construction of taller wood buildings, seeking for innovative technologies that expand the possibilities for taller walls, bigger spans, and stronger structures. This is an effective option to provide more affordable housing and promote urban density growth. The National Building Code in Canada allows the practice of light wood-frame construction up to four storeys.
Buildings account for 30–40% of the total primary energy use globally. While approximately 30% of energy use in Canada is consumed in buildings, where 64% of the energy consumption in residential buildings is space heating. One of the primary functions of building enclosure is reducing space-heating energy. Although heat flow cannot be completely prevented, it can be controlled to reduce energy consumption, create a sustainable environment, and implement indoor human comfort. However, this can be achieved by constructing a thermally resistant building enclosure. This study aims at developing and evaluating some innovative potential energy efficient wall systems for mid-rise wood frame buildings regarding their long-term thermal and structural performances. A test house was designed and installed at the University of Alberta field, where the wall systems were employed for field-testing. Several sensors such as thermocouple, heat flux, and moisture sensors, were installed on stud (structural component) and cavity (insulation component) of each wall system for long-term monitoring in severe weather conditions of Alberta. The wall systems were also tested in the University of Alberta I.F. Morrison Structures Laboratory for their structural capacities, where the researchers focused on concentric and eccentric vertical load-bearing capacities. The preliminary results show that I-Joist wall system with 16-inch spacing had the highest RSI value, while the Conventional wall system recorded the highest load-bearing capacity.
Key words: Energy efficiency, thermal performance, building envelope, load-bearing capacity, light wood-frame, mid-rise construction.

4. Recoverable chelating surfactants for selective removal of process disturbing divalent metal ions

Author(s): Susanne Boija, Håkan Edlund, Dan Bylund, Erik Hedenström, Magnus Norgren
Corresponding author: Magnus Norgren
Affiliation: FSCN, Mid Sweden University
E-mail: Magnus.Norgren@miun.se
Abstract:
The necessity to remove disturbing metal ions to assure the process efficiency and the quality of the product is highlighted in different industries, such as the pulp and paper industry. Today, the removal of metal ions is mainly performed with water soluble chelating agents such as ethylene diamine tetraacetic acid (EDTA) and diethylene triamine pentaacetic acid (DTPA). In this study the surface active chelating agent 4-C12DTPA, designed within the research group, is investigated in its ability to remove disturbing metal ions through foam flotation. The amount of removed metal ions in the solution is determined through inductively coupled mass spectrometry measurements. Moreover, by monitoring competition in mixtures of metal ions, 4-C12DTPA and DTPA with electrospray mass spectrometry, the strength of the complexes are compared. Initial studies at pH 5 indicates that more than 95% of the metal ions can be recovered with 4-C12DTPA in around one hour of flotation and the stability constants are very similar to DTPA for all metal ions investigated. This gives a strong indication that the 4-C12DTPA is a good substitute to DTPA and can also after use be recovered from the process water.
Key words: Recoverable chelating agents, surfactants, DTPA, flotation, ESI-MS, divalent metal ions

5. Antimicrobial susceptibility testing in paper-based portable culture devices

Authors: Frédérique Deiss
Corresponding author: Frédérique Deiss
Affiliation: University of Alberta
E-mail: deiss@ualberta.ca
Abstract:
We previously demonstrated the application of paper-based devices made of simple materials like tape, paper, and PDMS for bacterial culture [1]: gas-permeable membranes (PDMS) supplied a flow of oxygen, paper-pad acted as media reservoirs, wax-patterned papers defined culture zones, and tape sealed devices. We adapted these portable, paper-based culture devices for antimicrobial susceptibility tests (AST) by adding two reservoirs for antibiotics in the culture zone. We performed AST in these paper-based culture devices with pathogenic and non-pathogenic bacteria (i.e., E. coli K12, E. coli O157H7, and S. typhimurium) and compared the results with the standard Kirby-Bauer disk diffusion method on agar plate. PrestoBlue™, a cell viability colored indicator, allowed visualizing the presence of bacteria around reservoirs containing specific antibiotics. The area of inhibition of bacterial growth is proportional to the susceptibility of the bacteria to the tested antibiotic. Therefore, simple, disposable, portable, paper-based devices can be used in low-resource settings to determine the susceptibility or resistance of certain bacteria in biological fluids, environmental or food-borne samples to targeted antibiotics, and thus guide towards a potential treatment.
Key words:

6. Lignin-based Carbon Fibers

Authors: Angela P. Dodd, S.K. Straus
Corresponding author: Angela P. Dodd, S.K. Straus
Affiliation: University of Brittish Columbia
E-mail: angela.dodd@weyerhaeuser.com
Abstract:
Technology: Carbon fiber represents one of the materials of the future, given its light weight and high strength. It is being developed for automotive applications, but is not commonly found in cars yet because of its high cost of production. Compared to steel, which is priced as less than one dollar per pound, carbon fiber is expensive, coming in currently at ≈ $10 per pound. In order to make it into a viable product, the price of carbon fiber must be cut by at least half. One important way to make this happen is to mix the current starting materials used for making carbon fiber, e.g. polyacrylonitrile (PAN), with wood products such as lignin. We have recently demonstrated, in collaboration with Zoltek, that it is not only possible to make carbon fibers based on a mixture of PAN and lignin, but that such a fiber can have strength properties exceeding those defined by the US DOE as target for automotive application. In addition, we have shown that such a fiber can be produced on a large scale. The projected cost of this lignin-based carbon fiber approximately $5/lb, making this a viable product derived from wood as a raw material.
Project: Carbon fiber can also be used in a variety of other ways, e.g. aeronautical industry. For this, however, it will be necessary to create the next generation of lignin containing carbon fibers with even higher strength.
The goal of our research is to develop a method to easily evaluate new lignin sources, modified lignins and lignin fractions as possible feedstocks for enhanced lignin-based carbon fibers. Various lignins will be produced on a small scale for analysis. Characterization of lignins will include a full chemical analysis through NMR, molecular weight, sulfur content (if applicable), carbohydrate content, ash content and thermal properties. These novel lignins will be tested for miscibility with PAN at various levels. The lignins and lignin/PAN blends will then be oxidatively stabilized and carbonized on a small scale. At each stage, the aromatic and graphitic structure will be measured using solid state NMR, FT-IR, DSC and pyrolysis GCMS. The results will be used to evaluate the lignin’s tendency to form the stable, graphitic structure necessary for high strength carbon fiber. Finally, the lignins which show the highest potential will be used to form actual carbon fibers in which the strength properties can be measured and correlated to previous work.
Key words:

7. Light-weight composite materials from bio-based “waste”

Authors: Ran Duan
Corresponding author: Ran Duan
Affiliation: Mid Sweden University
E-mail: ran.duan@miun.se
Abstract:
In our project the objective is to produce light-weight composite materials from bio-based “waste” and fibers/paper. Dissolved hemicelluloses, fibrils and fibers will be used as raw materials. Different raw materials, methods and chemistry will be combined to reach interesting product properties and applications.
Different porous materials produced from starch, xylan or GGM show low density, high porosity and a high small porous amount which give a good possibility in absorption application. So, different measurements were preformed on produced materials to describe absorption properties of the end products such as cell structure, density, porosity, liquid absorption, contact angle and so on.
Some samples show the potential to obtain good wet durability and to use as absorption materials. But some problems also need to be overcome, such as improve other properties beside absorption of produced material to get closer to synthesized materials and found better routine to produce them in a bigger scale
Key words:

8. Fire-retardant foams and composite materials

Authors: Maryam Ghanadpour
Corresponding author: Maryam Ghanadpour
Affiliation: KTH Royal Institute of Technology
E-mail: marygp@kth.se
Abstract:
The overall goal of my project is to develop fire-retardant foams and composite material. Different applications such as being used in building/construction materials or in the transport industry are considered for such material. Developing nano-cellulose based material is one of the main objectives followed in this project. In order to achieve fire-retardancy properties cellulose fibers/fibrils are being chemically modified, further they can be combined with inorganic components to optimize structure and strength of the material. In addition to chemical modifications, optimal surface finishes are being used to reach our goal; effective fire-retardant coatings are created through layer-by-layer assembly of suitable polyelectrolytes and inorganic nano-particles. Examining the effect of the choice of components and conditions during surface modifications as well as analysis of relationships between structure, surface treatment and fire retardancy are included in this study.
Key words:

9. The feasibility to produce ρ-cymene

Authors: Mikhail Golets
Corresponding author: Mikhail Golets
Affiliation: Umea University
E-mail: Mikhail.Golets@chem.umu.se
Abstract:
The aim of this work is to demonstrate the feasibility to produce ρ-cymene, an important commodity chemical, in a continuous, one-pot reaction system from abundant α-pinene, available e.g. as a by-product of pulping industry. The mentioned ρ-cymene could be further converted to the terephthalic acid or acetophenone, which are perspective precursors for the plastics, in contradistinction to the hazardous petrochemical-related raw materials. The present project proposes a one-step green conversion of renewable feedstocks into value-added chemicals during the solventless catalytic process. In addition, industrial turpentine resided after the mechanical pulping could be utilized in the same way. In the process, heterogeneous self-prepared inorganic-based catalysts are applied. The kinetic study of the reaction network is confirmed by the consecutive kinetic modeling and the substantial catalyst characterization part is presented.
Key words:

10. Cross-flow filtration for fractionation of wood components

Author(s): Mikaela Helander. Main supervisor Prof. Mikael E. Lindström. Research mentioned in the abstract is done in collaboration with others.
Corresponding author:Mikaela Helander
Affiliation: KTH, Wallenberg Wood Science Center
E-mail: helande@kth.se
Abstract:
A large and important natural resource in Sweden is the forest and about 70 % of the land area is woodland. Wood could be the ultimate raw material for replacement of oil-based products since it is renewable, biodegradable and carbon neutral.
A key to succeed producing new products from wood is to have a pure raw material. Since wood contains a big variety of components with different structures and sizes it is necessary to understand processes that can produce fractions of more homogeneous raw material. Hence, cross-flow filtration is a technique of most importance. By using this technique it could be possible to tailor the properties regarding size, molecular weight and functional groups of a raw material for producing high value-added products.
In our research we have been working with several components in wood, such as; lignin, hemicelluloses and microfibrillated cellulose (MFC). Today, approximately 2.5 million metric tons of kraft lignin is being produced in Sweden and most of it is being used as fuel, hemicellulose is being extracted in pulp mill waste waters and MFC has great potential due to its physical properties. These materials become inhomogeneous by nature, but by the use of cross-flow filtration we have succeeded to produce more homogenous raw materials.
Key words: Filtration, Fractionation, Lignin, Hemicelluloses, microfibrillated cellulose, MFC

11. Production of ethanol from softwood

Author(s): Kerstin Hoyer
Corresponding author: Kerstin Hoyer
Affiliation: Lund University
E-mail: kerstin.hoyer@chemeng.lth.se
Abstract:
Ethanol can be used to replace fossil fuels in the transport sector. Producing ethanol from lignocellulose like softwood instead of starch or sugar rich crops, decreases competition with food and feed production and results in greater savings in greenhouse gases emissions.
In ethanol production from softwood, enzymes convert the cellulose to glucose which can be fermented to ethanol using ordinary Baker’s yeast. We perform these steps simultaneously in so-called simultaneous saccharification and fermentation (SSF), since this has been shown to result in higher ethanol yields.
For process economics, it is vital to reach high ethanol concentrations after fermentation. Therefore, SSF needs to be performed at high substrate, i.e. solids, concentrations, which, however, reduces the ethanol yield. We have studied different process configurations in order to increase ethanol concentration without substantial yield loss and have been able to produce ethanol from softwood reaching ethanol concentrations as high as 65 g/L, which is well above the 4 wt%, which is suggested for economical distillation of the fermentation broth in the production of ethanol from lignocellulosic biomass.
Key words:

12. Studies on TEMPO oxidation of cellulose and oxidized nanofibrils

Authors: Thomas Hänninen
Corresponding author: Thomas Hänninen
Affiliation: VTT Technical Research Centre of Finland
E-mail: tuomas.hanninen@vtt.fi
Abstract:
TEMPO ((2,2,6,6-Tetramethylpiperidin-1-yl)oxy) oxidation is a highly selective method to oxidize primary alcohols of cellulose fibrils without significantly disrupting their crystalline structure. TEMPO oxidized cellulose nanofibrils can be used to prepare highly translucent films for various applications. TEMPO oxidized films can be used, for example, as membranes for heavy metal ion recovery. Oxidized nanofibrils can also be used to produce hydro- and aerogel structures. Such materials have potential as absorbent materials or as materials in medicine. TEMPO oxidation reactions and stability of different kinds of cellulose surfaces can be observed using quartz crystal microbalance with dissipation monitoring (QCM-D). Optimal oxidation conditions depend greatly on the cellulosic material used for surfaces. TEMPO oxidized nanocellulose surface for QCM-D can also be produced by more conventional method, spin coating.
Key words:

13. Mild Steam Explosion of Spruce Wood

Authors: Kerstin Jedvert
Corresponding author: Kerstin Jedvert
Affiliation: Chalmers University of Technology
E-mail: jedvert@chalmers.se
Abstract:
In a more sustainable society, it would be beneficial to better utilize the different components of wood for use in production of novel materials, chemicals and fuels. However, due to chemical bonds and interactions between the constituents in wood, it is a challenge to separate them without heavily degrading one or more of the components. The use of enzymes is one possible method to break bonds specifically, but in order for enzymes to access a wood structure, it needs to be less compact. Steam explosion, where saturated steam is applied to biomass at elevated temperature and where the pressure then is rapidly released, could potentially be used as a pre-treatment to achieve a more porous structure. During a steam explosion treatment degradation reactions due to autohydrolysis usually occurs; and it is therefore important to keep the conditions during the steam explosion treatment mild.
The aim of this research is to investigate the effects of a mild steam explosion treatment on material from Norway spruce (one of the most common wood species in Scandinavia). The samples are characterized and analysed with both physical and chemical methods and the effects of the mild steam explosion treatment is followed also during subsequent treatments, such as enzymatic reactions and kraft pulping.
Key words:

14. Functional wicking surfaces

Author(s): Eveliina Jutila, Risto Koivunen, Patrick, Gane
Corresponding author: Eveliina Jutila
Affiliation: Aalto University, School of Chemical Technology, Department of Forest Products Technology
E-mail: eveliina.jutila@aalto.fi
Abstract:
Paper-based microfluidic analytical devices are aimed at being low-cost, portable and disposable. They should be simple and easy to use, and provide fast diagnosis in the case of medical application. The basic principle of paperfluidic devices is as follows: a drop of sample, for example a bodily fluid, such as blood, is either placed on the device or the device is dipped into the sample, after which the paper wicks the fluid through walled channels, derived from hydrophobic containment, and guides it to various stations where either enzymatic, colour changing or some other means of detection takes place. Wicking refers to the spontaneous suction of a liquid into a porous medium due to capillary pressure.
The aim of our project is to develop and design coated functional wicking substrates for diagnostic and analytical printed test kits, which have the potential to provide better spatial resolution and thus requiring less volume of test sample. Following screening of many options, the chosen coating pigments include porous modified calcium carbonate (MCC) and diatomaceous earth (diatomite). The chosen binder in the first experiments is a styrene acrylic (SA) latex binder.
Experiments show that wicking is strongly influenced by the coating pigment type and applied binder level. Higher binder levels are confirmed to inhibit wicking. Noticeably faster wicking can be achieved with the inclusion of flux-calcined diatomite rather than natural diatomite.
To establish suitable hydrophobic patterns inkjet printing on filter paper has been used, and tested with various probe liquids.
Key words:
Microfluidic devices, diagnostic and analytical printed test kits, wicking, hydrophobic channels

15. Biofuels and chemicals from abundant and accessible forest industry streams: Spruce bark and recovered fibres

Author(s): Katariina Kemppainen
Corresponding author: Katariina Kemppainen
Affiliation: VTT Technical Research Centre of Finland
E-mail: katariina.kemppainen@vtt.fi
Abstract:
Forest industry value creation may be boosted by refining currently combusted side- and waste streams to transport biofuels and chemicals. Spruce bark is an abundantly available side-stream in the Nordic countries characterized by its high potential as a source of condensed tannins, which are phenolic compounds having existing markets and plenty of new opportunities as a replacement for fossil-based chemicals. Recovered fibres are a stream, which can be fractionated from solid recovered fuel (SRF), a market fuel typically produced from commercial and retail packaging waste. High carbohydrate content and low cost of the fibre fraction makes it particularly suitable for sugar platform biorefinery processes such as ethanol production. Both streams are currently collected for combustion, and their upgrading does not affect existing forest industry processes. We have studied a number of process steps related to biorefinery concepts based on these raw materials including hot water extraction of tannin from spruce bark, pretreatment, hydrolysis, and fermentation of bark and its sugars, fractionation of recovered fibres from SRF, and hydrolysis and fermentation of recovered fibres from laboratory to pilot-scale. Among the highlights of the research are the production of spruce bark extracts with up to 50% tannin content in laboratory and pilot-scale, and the successful operation of continuous pilot-scale campaigns consisting of liquefaction, simultaneous saccharification and fermentation, and biogas production from recovered fibres.
Key words:
spruce bark, recovered fibres, tannin, ethanol, enzymatic hydrolysis, fermentation

16. The bark biorefinery: creating value from polysaccharides of spruce bark

Authors: Myriam Le Normand
Corresponding author: Myriam Le Normand
Affiliation: KTH Royal Institute of Technology
E-mail: myriamln@gmail.com
Abstract:
Manufacturing processes for pulp, paper and timber production generate large quantities of bark. The quantity of bark from Norway spruce is estimated to represent around 1.5 million tons/year in Sweden alone. The idea behind the bark biorefinery concept is to recover different components from the bark of Norway spruce prior to its combustion and upgrade the fractions to several value-added bio-based products. The bark of Norway spruce is a highly complex and heterogeneous material. A few bark constituents have already found applications (e.g. tannins for adhesives). Our idea was to extract, characterize and test the properties of components which had never been studied before, i.e. the non-cellulosic polysaccharides. The major non-cellulosic polysaccharides found in the bark of Norway spruce were pectins and starch and could be extracted with hot-water. These extracts showed promising immunostimmulating activities, providing ideal candidates for the development of therape utics with immunomodulatory action. In addition to their bioactivity, non-cellulosic polysaccharides from spruce bark showed good film-forming properties and could be used for coating applications. The residue of extraction was used for the production of cellulose nano-crystals, which are being characterized and used to improve the properties of the polysaccharides films.
Key words:

17. Polyesters and Composites Based on Birch Suberin

Authors: Dongfang Li
Corresponding author: Dongfang Li
Affiliation: KTH Royal Institute of Technology
E-mail: dongfan@kth.se
Abstract:
Natural and hydrophobic structures such as suberin are suitable candidates for improving the water repellency of cellulose surface. Suberin is rich in birch (Betula verrucosa) outer bark. In Scandinavia, birch bark is a side-stream product from the forest industry and normally used as a solid fuel for energy production, though other value-added applications are indeed possible considering the biorefinery concept. In this study, a suberin monomer, cis-9,10-epoxy-18-hydroxyoctadecanoic acid, was isolated from birch outer bark, and polymerized via lipase (immobilized Candida antarctica lipase B) catalysis. The formed epoxy activated polyesters were characterized by NMR, MALDI-TOF MS, and SEC. Composites were prepared through compression moulding of polyester impregnated cellulose sheets. The composites were characterized by FTIR, CP/MAS 13C NMR, SEM, and DSC. An improved hydrophobicity was shown by contact angle measurement. Our current study is a sub-project of WOBAMA (Wood Based Materials and Fuels), a Wood Wisdom-Net Research Program among many participants from academics and industries in EU.
Key words:

18. Lignin Carbon Nanofibers for EMI Shielding

Author(s): Yingjie (Phoebe) Li and Frank Ko
Corresponding author: Prof. Frank Ko
Affiliation: University of British Columbia
E-mail: frank.ko@ubc.ca
Abstract:
Lignin-based carbon nanofibers with electromagnetic properties were successfully prepared by electrospinning and subsequent carbonization. The electrical conductivity was introduced to the lignin based carbon nanofibers through carbonization. Magnetic properties were incorporated into lignin composite nanofibers by embedding magnetic nanoparticles using in situ synthesis. By combining magnetically permeable and electrically conductive functions, a new family of hybrid lignin composite nanofibers has been created. The electromagnetic interference (EMI) shielding effectiveness of lignin based carbon nanofiber was found to be comparable to that of conventional petroleum-based carbon nanofiber. The EMI shielding performance of electromagnetic lignin carbon nanofiber has met the commercial application requirements.
Key words: Lignin, carbon nanofiber, EMI shielding

19. The feasibility of extracting nanocrystalline cellulose from logging residues

Authors: Rosana Moriana Torró
Corresponding author: Rosana Moriana Torró
Affiliation: KTH Royal Institute of Technology
E-mail: rosana@kth.se
Abstract:
The cleaning, thinning and final felling of forest stands generate large quantity of small trees, branches, needles, tops and un-merchantable wood that constitute the totality of the forestry wastes. These wastes are often subjected to a controlled burn or in the worst cases are left in mountains causing a negative environmental impact. In the warmest European countries, this practice constitutes a potential hazard in terms of fire and pests risks. The development of new materials from wood residues could help to solve the environmental problems related to an inefficient forest waste management, constituting at the same time an alternative to fossil resources. The purpose of this work is to study the feasibility of extracting nanocrystalline cellulose from logging residues to later develop green nanocomposites. The biomass wastes were obtained from a Swedish forest. The thermal properties, functionality, and morphology of all the materials were assessed to evaluate the mor phological arquitecture of cellulose-chains during conversion from macro to nano dimensions. This work means a new insight into the isolation of cellulosic nanocrystals from wood waste to ensure their suitability as future reinforcements in nanocomposites. First prototypes were developed and their overall macroscopic properties were discussed in terms of their mechanical and thermal performance.
Key words:

20. Increasing filterability of black liquors by prefiltration

Author(s): Johanna Olsson, Anders Arkell
Corresponding author: Johanna Olsson
Affiliation: Lund University/ SunMembrane AB
E-mail: johanna.olsson@chemeng.lth.se
Abstract:
The recovery boiler is often a bottleneck in the production of kraft pulp and paper. By removing some of the organic material from the black liquor (BL), the load on the recovery boiler could decrease without the need of replacing the recovery boiler itself. Membrane filtration is an available technique suitable for separation of organic material in BL. During this work, membrane filtration of both hardwood and softwood BL were performed. It is known that BL originating from hardwood is more difficult to filter and therefore a
comparison between filterability of both types was of interest. In order to study separation performance, different process configurations have been investigated. Nanofiltration (NF) was used for recovering of both hemicelluloses and lignin, ultrafiltration (UF) for the separation of hemicelluloses and NF on permeate from UF for the isolation of lignin. During the study it was found that hardwood black liquor was more difficult to filter than softwood black liquor, which has been shown earlier. However, UF before NF increased the filterability considerably for hardwood BL. This made the membrane performance reach values in the same range as when softwood black liquor was used. The conclusion was that the hemicellulose, which could be removed by UF, severely impairs the filterability of hardwood BL.
Key words:
Kraft black liquors, Membrane filtration, Nanofiltration, Ultrafiltration

21. Modified vegetable oils as “green” protection of exterior wood

Authors: Sara Olsson
Corresponding author: Sara Olsson
Affiliation: KTH Royal Institute of Technology
E-mail: sara.olsson@sp.se
Abstract:
The project aim is to enhance the UV protection of clear coated wood for exterior applications in a more environmentally friendly way. This is achieved by using a reactive pretreatment of epoxy functional vegetable oils and a UV-absorber, both with the ability to react covalently with the wood surface. This covalent bond, and the presence of hydrophobes, inhibits leakage of the UV-absorber, which is a common issue in UV-protection of clear coating systems today. As the UV-absorber hinders the UV-light from reaching the wood surface the vegetable oil hydrophobises the surface, which in turn also decreases the degradation due to less moist in the wood.
The study was divided into two parts where the first part focused on the practical aspects of developing and testing the pretreatments, using both accelerated and natural weathering. Results from the first part shows that the pretreatment seems to work, giving an improved UV-resistance. The second part is on-going and focuses on increasing the understanding of interactions between epoxy functional vegetable oils/UV-absorber and wood by using model substances of lignin. The aim of the project is hence to create a more environmentally friendly UV protection for clear coated exterior wood by using renewable resources.
Key words:

22. Nano-ligno-cellulose as strength enhancer in handsheets

Author(s): Sinke H. Osong, Sven Norgren, Per Engstrand
Corresponding author: Sinke H. Osong
Affiliation: Mid Sweden University
E-mail: henshaw.sinke@miun.se
Abstract:
In recent years, there has been tremendous work in the research field of nanocellulose or microfibrillated cellulose but, very few scholars have envisioned the use of the low quality fibre fraction of mechanical pulps for the production of mechanical pulp based nanocellulose, referred to as nano-ligno-cellulose (NLC) in this paper. Today, it has been noticed by many that there has been an economic downturn in the pulp and paper industry and that this adverse situation could be somewhat alleviated by possibly searching for better products or by improving the material quality of existing products (papers and paperboards). This paper presents results related to paper strength properties based on testing of handsheets of pulp fibres blended with nanocellulose. The results indicate that the addition of nano-ligno-cellulose (NLC) to chemi-thermomechanical pulp (CTMP) fibres improved the z-strength property of laboratory sheets with only a slight effect in relation to the sheet density. Also the crill characterisation method was used to evaluate fibre size distribution. The measurement of crill is based on optical response of a suspension at two wavelengths of light; UV and IR. The UV light contains information on both the total fibres and the crill, while IR only contains information on fibres. Results showed that the crill value of NLC of CTMP correlated (linearly) fairly well with the homogenisation time.
Key words: chemi-thermomechanical pulp, homogenisation, nanocellulose, z-strength, crill,

23. Production of superhydrophobic coatings by spraying from gas saturated solutions

Author(s): Louise Ovaskainen, Samuel Chigome, Nelson Torto, Charlotta Turner, Lars Wågberg
Corresponding author: Louise Ovaskainen
Affiliation: KTH Royal Institute of Technology
E-mail: Lollo3@kth.se
Abstract:
A high pressure spraying technique, the rapid expansion of supercritical solutions (RESS) has been used to make superhydrophobic coatings of a non-fluorinated polymer. Particles are produced in the RESS process by dissolving a substance in a supercritical fluid and releasing the pressure by expanding the mixture through a nozzle. A copolymer, poly(vinyl acetate)-poly(vinyl pivalate) (P(VAc-VPi)) was dissolved in acetone and supercritical carbon dioxide and then sprayed onto silica surfaces. The spray distance and polymer concentration was varied in the study. The produced surfaces were characterized in terms of their morphology and hydrophobic properties by scanning electron microscopy and contact angle measurements, respectively. The contact angles of the P(VAc-VPi) coatings were 148-165° and the tilt angles at which a 5 μL water droplet rolled off were 5-11°. These results are promising for the creation of superhydrophobic coatings with non-fluorinated polymers by using the RESS technique.
Key words: Coating, superhydrophobic, polymer, PVAc-PVPi, supercritical carbon dioxide

24. The Role of Bio-based Products in a Carbon-efficient Building Environment

Author(s): Diego Peñaloza
Corresponding author: Diego Peñaloza
Affiliation: SP Technical Research Institute of Sweden
E-mail: Diego.Penaloza@sp.se

Abstract:
The construction sector is responsible for a large share of society’s greenhouse gas emissions. All this calls for measures towards a more sustainable built environment. The extent of the role of bio-based products in the carbon footprint of a building case study has been explored using Life Cycle Assessment (LCA.
A cradle-to-grave LCA was conducted for eight design alternatives for Wälluden, a four-storey multi-family building in Växjö, Sweden. The designs consist of three building systems (prefabricated volume elements, massive timber structural elements and a column-beam structure), each under standard and passive house energy efficiency categories; as well as the original design of the building both with wood and concrete frame structures. The results show that increasing the share of bio-based products can decrease the carbon footprint of the production phase of a building, no matter which building system is chosen. Bio-based materials have higher potential environmental benefits for the end-use phase, depending on the fate of the material. The benefits of more use phase energy efficient designs are significant, but as the use-phase impact lowers and there is less improvement potential; both the production and end-use phase become more relevant.
Regarding future research, there is an increasing demand for forest products from different sectors. All these uses of the forests promise environmental benefits based on their lower environmental impact and substitution effects, but the forest is a limited resource which must be distributed among all these needs. This is why a comparative assessment of the environmental benefits from different uses of the forest is needed as a tool for decision-making.
Key words:
Life Cycle Assessment, Sustainable construction, Bio-based products, Carbon Footprint

25. Cellulose Spheres for Contact Adhesion Testing

Authors: Samuel A. Pendergraph
Corresponding author: Samuel A. Pendergraph
Affiliation: KTH Royal Institute of Technology
E-mail: spender@kth.se
Abstract:
Cellulosic materials have been studied extensively due to their attractive material properties and their natural abundance. Proliferation of these materials has been hindered by the poor surface interactions with other materials. Conversely, many research efforts have been focused on modification of cellulose interfaces to create composite structures. However, there have been fewer reports on quantitative adhesion of these cellulosic interfaces. Furthermore, in the majority of these studies, there has been focused on purely on the critical separation force and have not quantified the energy release rate as a function of loading conditions. In this presentation, we present a new method to evaluate the adhesion of cellulose materials. Specifically, we used established techniques to form smooth cellulose spheres with tunable sizes, geometries and surface charges. Previously studied chemical modification techniques can be applied and subsequently tested directly on the same material. This will enable a more accurate testing method for new cellulosic composite structures.
Key words:

26. On the Development of Nanofibrillated Cellulose templates for Functional Materials

Authors: Maria Soledad Peresin, Tekla Tammelin, Jari Vartiainen, Leena-Sisko Johansson, Monika Österberg
Corresponding author: Maria Soledad Peresin
Affiliation: VTT Technical Research Centre of Finland
E-mail:
soledad.peresin@vtt.fi
Abstract:
Challenges on the manufacture of nanocellulose films are non-trivial when it comes to obtain large, smooth and fully reactive nanocellulose films. Among such challenges, the removal of high amounts of water present in gel-like nanocellulose suspensions has been one of the main drawbacks in terms of up-scaling nanofibrillated cellulose (NFC) film manufacture technology. Furthermore, during film formation, the hydrophilic nature of nanocellulose favours the accumulation of airborne contaminants on its surface, diminishing its reactivity by hampering potential sites for further chemical functionalization and restricting its potential applications.

In this contribution recent advances in up-scaling NFC film manufacturing technology will be discussed and special focus will be dedicated to our current efforts on the development of a strategy to control, effectively activate and thus enhance the reactivity of nanocellulose film surfaces.
We had developed a simple, solvent-free and low cost method based on the oxidative properties of UV radiation and ozone that allows the effective removal of contaminants from nanocellulosic surfaces, which remain clean and reactive for at least a week. Significant improvements in surface modification, degrees of substitution and printing quality were observed upon activation of NFC films. Such development has a direct impact in several applications for NFC substrates such as flat panel displays, printed electronics and diagnosis, packaging and health care products to name a few.

Key words: nanofibrillated cellulose films; large scale; surface modification; barrier properties

27. Polymers derived from isolated hydroxy acids obtained from hardwood and softwood black liquor

Authors: Minni Pirttimaa
Corresponding author: Minni Pirttimaa
Affiliation: VTT Technical Research Centre of Finland
E-mail: minni.pirttimaa@vtt.fi
Abstract:
Black liquor is formed as a side product of the pulping industry, and typically it is used as a source of energy for the mill. Black liquor contains a significant amount of carboxylic acids, which have low heat values. Therefore, the carboxylic acids may be separated from black liquor and valorized in a number of
biopolymer applications. In this study, several black liquor fractions were polymerized and the obtained
polymers were characterized. The fractions were, for the first time, successfully polymerized. Polymers with Tg -1-49 °C and Mw 750-2400 g/mol were obtained. The best results (Tg 49 °C, Mw 2400 g/mol) were obtained using fraction, which had the most even OH/COOH ratio. Potential applications for the polymeric materials obtained from black liquor are foreseen to be, hotmelt adhesives, plastizicer and thermosets or functional materials after further modification of OH-groups.
Key words:

28. Effects of Interface Tailoring in Cellulose Nanofibre Based Composites

Author(s): Kasinee Prakobna and Lars A. Berglund
Corresponding author: Lars A. Berglund
Affiliation: WWSC, KTH, SE-100 44 Stockholm, Sweden
E-mail: blund@kth.se
Abstract:
Cellulose nanofibrils have attracted great interest as a potential reinforcing component in nanocomposite materials due to supreme mechanical properties and inherent capability in network formation. The distribution of consitutents is one of the crucial parameter to determine final properties, especially mechanical performance of the nanocomposite materials.

In the presence study, novel concept of core-shell nanofibrils is introduced in order to control better distribution of matrix constituents which is elaborately coated on cellulose nanofibrils. The tightly bound polymer matrix has a strong impact on the progress of matrix distribution in nanoscale interface. A unique nanocomposite film based on the core-shell nanofibrils was obtained by filtration and vacuum drying. The obtained core-shell nanocomposite film exhibits better moisture stability and outstanding improvement of tensile properties at both ambient and highly hydrated state. We successfully improve mechanical performance of all polysaccharide-based materials by taking advantage of NFC network and superior interfacial interaction between the nanofibrils and polymer matrix.
Key words: Nanofibrillated cellulose (NFC), nanocomposites, matrix distribution

29. Wood cell walls: the “ideal” composite

Author(s): Tahereh Behzadi, Ramiro Rojas, Lars A. Berglund
Corresponding author: Ramiro Rojas
Affiliation: Wallenberg Wood Science Center, KTH Royal Institute of Technology
E-mail: ramiro@kth.se
Abstract:
Wood cell walls are the “ideal” composite: they consist of stiff cellulose nanofibrils embedded in a soft matrix of hemicelluloses and lignin binders. These structural features correspond to the requirements for composites to be stiff and though. While there are major efforts in the study of materials based on cellulose nanofibers there are other opportunities in taking advantage of the inherent interactions between cellulose and matrix substances. A recent research effort in our group is to obtain homogeneous lignin/hemicellulose-coated cellulose fibrils by using mild chemical and mechanical treatments amenable to the pulp and paper industry. Our hypothesis is that when preserving all three major wood components within wood-derived nanofibrils, we can create “all wood”-based biocomposites and will potentially obtain an enhanced affinity with hydrophobic, conjugated matrices or fillers through an improved interface. Ultimately we expect to contribute to the efforts on renewable materials composed of all three major wood components and their use in biocomposites for advanced technologies.
Key words:
Mechanical pulp, biocomposites, nanocellulose, lignin, hemicelluloses, interfaces

30. Origami Engineering: Advanced Converting for Novel Products

Authors: Ata Sina
Corresponding author: Ata Sina
Affiliation:University of British Columbia
E-mail: atasina@gmail.com
Abstract:
A novel method and apparatus has been developed to create self-folding paper products. This platform technology enables complex 3-D shapes to be created from 2-D sheets of paper that can be used for a wide range of green products from artistic and decorative materials to custom impact resistant packaging or insulation.

The self-folding material is a composite of pre-cut and creased paper bonded to a heat shrinking polymer film. To achieve a particular 3D shape the folds and creases are first designed using computational drawing tools. The folds and creases are then carried out using a computer numerical controlled (CNC) cutter that can cut and crease paper using a knife with variable pressure. The same device is also used to cut the thermoplastic polymer. The cut and creased paper is then bonded to the cut heat shrinking polymer film. Several methods have been used to attach the thermoplastic polymer to the paper including adhesives, sewing and welding. Current demonstration of the technology has used welding that is accomplished using an in-house developed servo-robot designed to carry out the welding automatically. The polymer is bonded on 2 sides bridging the crease the needs to be folded. Folding is activated by heating the polymer which contracts the paper across the crease and results in a fold. The composite material can be heated using a conventional heat gun or placed in an oven for a short period of time. All folds are created simultaneously to create a complex 3-D shape in only a few seconds.
A large number of polymeric materials and several means of attaching the polymer to the paper have been explored. The effect of pressure, temperature and time of applying pressure, thickness of paper, paper material, etc on folding has been determined. Several examples of folded decorative products have been developed using this technique and are available for demonstration. Recent work has focused on determining what thickness of paper that can be folded (including corrugated materials) and to determine what the resulting strength of the folded material will be.
Key words:

31. Biofuels and chemicals from lignocellulosics – general overview of a process for conditioning SO2-ethanol-water spent liquor for ABE fermentation

Author(s): Evangelos Sklavounos
Corresponding author: Evangelos Sklavounos
Affiliation: Aalto University
E-mail: evangelos.sklavounos@aalto.fi
Abstract:
A process is developed to allow for conditioning of spent liquor produced by SO2-ethanol-water (SEW) fractionation of different lignocellulosics for fermentation to biofuels and chemicals via ABE (acetone-butanol-ethanol) fermentation technology utilizing Clostridia bacteria.
SEW fractionation technology is employed to release hemicellulose derived sugars from different lignocellulosic feedstocks in only 30 min at 150oC. However, the dissolved sugars cannot be directly subjected to fermentation and further processing, i.e. conditioning, is needed. For instance, the acidic SEW spent liquor has a relatively high oligomers content and further fractionation is needed to increase monomers share before the liquor is suitable for fermentation. Additionally, the pH of SEW spent liquor requires adjustment to neutral levels to avoid harming the bacteria. Furthermore, fractionation chemicals i.e. ethanol and SO2 are fermentation inhibitors and therefore must be fully removed and recovered to obtain an economical process. Soluble lignin, furans and other fermentation inhibitors must also be removed to allow for unhindered ABE fermentation.
The developed conditioning scheme successfully meets the above requirements. Fermentation of all conditioned liquors by Clostridia bacteria produced ABE solvents (mostly butanol) at high total concentration and yield.
The presentation concentrates on providing a general overview of the developed scheme for conditioning SEW spent liquor from lignocellulosics for ABE fermentation to biofuels and chemicals.
Key words:

32. Sub-micron scale cellulose nanofibers regenerated from ionic liquids using electrospinning

Authors: Johannes Thunberg
Corresponding author: Johannes Thunberg
Affiliation: Chalmers University of Technology
E-mail: johannes.thunberg@chalmers.se
Abstract:
Ionic liquids are pure salts that are liquid at room temperature and some of them have the ability to dissolve cellulose, and they also possess unique properties like negligible vapor pressure and low flammability. These properties make ionic liquids suitable alternative for the viscose process, which is still the dominant manufacturing process for regenerated cellulose. In this research project sub-micron scale cellulose nanofibers were regenerated from ionic liquids using electrospinning as spinning technique.
Key words:

33. Recovery of hemicellulose by membrane filtration from waste streams of thermomechanical pulp mills.

Author(s): Johan Thuvander
Corresponding author: Johan Thuvander
Affiliation: Lund University
E-mail: Johan.Thuvander@chemeng.lth.se
Abstract:
Today, components in wood that could bring additional income to mechanical pulp mills are released into waste water streams and increase the burden on the waste water treatment plant. By recover and purify these components the cost of waste water treatment could be reduced at the same time as the mill could get new income from new products.
One way to recover and purify these valuable components is to use membrane separation technology. Membrane filtration is an energy efficient and low cost separation process which requires no addition of chemicals. One valuable substance in the waste water streams that can be recovered using membrane separation is hemicellulose which e.g. can be used to produce barrier films in food packaging. I perform filtration experiments and composition analysis of waste waters at Lund University in order to determine which membranes and process parameters shall be used in order to make the process as cost efficient as possible.
We have successfully developed a process for recovery of hemicellulose from waste streams from thermomechanical pulp mills. As the next step in transferring this technology to the industry we will in the near future perform pilot scale trails at a Swedish pulp mill.
Key words: Hemicellulose, Membrane filtration, Waste water stream, Thermomechanical pulp mill

34. Hydrolysis and dissolution of crystalline cellulose in subcritical and supercritical water

Author(s): Lasse Tolonen, Herbert Sixta
Corresponding author: Lasse Tolonen
Affiliation: Aalto University, Department of Forest Products Technology
E-mail: lasse.tolonen@aalto.fi
Abstract:
Water in its sub- and supercritical state is a highly interesting reaction medium for the conversion of biomass. Compared with ambient water, subcritical water has an increased hydrogen ion concentration without any added catalyst, which promotes hydrolysis reactions. When the temperature is reduced, the hydrogen ion concentration decreases without neutralization. At the supercritical temperatures several solvent parameters of water are shifted enabling, for instance, the dissolution of non-polar species that are insoluble in ambient water.
It is well known that cellulose is insoluble in ambient water. At subcritical temperatures cellulose can be hydrolyzed but no actual dissolution of polymers occurs.1 In the vicinity of the critical point (374 °C, 22.1 MPa) water, however, crystalline cellulose undergoes a crystalline-to-amorphous transformation and dissolves as a low molar mass polymer. When reaction times below one second are used, the dissolved cellulose can be recovered after cooling as solid cellulose precipitate.2
1. Tolonen et al. 2011, Biomacromolecules, 12, 2544-2551 doi: 10.1021/bm200351y
2. Tolonen et al. 2013, Cellulose, Published online doi: 10.1007/s10570-013-0072-7
Key words:
Cellulose dissolution, subcritical water, supercritical water

35. Polymerization of aniline within wood veneers

Authors: Stacy Trey
Corresponding author: Stacy Trey
Affiliation: SP Technical Research Institute of Sweden
E-mail: Stacy.Trey@sp.se
Abstract:
The present study describes the possibility to polymerize aniline within wood veneers to obtain a semi-conducting material with solid wood acting as the base template. It was determined that it is possible to synthesize the intrinsically conductive polymer (ICP) polyaniline in situ within the wood structure of Southern yellow pine veneers, combining the strength of the natural wood structure with the conductivity of the impregnated polymer. It was found that polyaniline is uniformly dispersed within the wood structure by light microscopy and FT-IR imaging. A weight percent gain in the range of 3–12 wt % was obtained with a preferential formation in the wood structure and cell wall, rather than in the lumen. The modified wood was found to be less hydrophilic with the addition of phosphate doped polyaniline as observed by equilibrium water swelling studies. While wood itself is insulating, the modified veneers had conductivities of 1 × 10–4 to 1 × 10–9 S cm–1, demo nstrating the ability to tune the conductivity and allowing for materials with a wide range of applications, from anti-static to charge-dispersing materials.
Key words:

36. Stabilization effect of lignin in refined and thermally treated pulp sheets

Authors: Emilia Vänskä
Corresponding author: Emilia Vänskä
Affiliation: Aalto University
E-mail: emilia.vanska@aalto.fi
Abstract:
Cellulosic fibers are inherently thermally sensitive and the modification of them to withstand
temperature is essential for applications such as food packaging. The usual protection methods
are mainly based on barrier coatings. However, herein we propose that it is possible to attain
paper with improved thermal stability through lignin-assisted refining of pulp. Fully bleached kraft
pulp was first treated with 2% of alkali lignin at pH 13.0 and subsequent precipitation induced by
lowering, the pH to 6.5 upon addition of sulfuric acid (0.98 M). Pulp refining was performed with a
Hollander laboratory refiner to Schopper-Riegler number 89. The presence of lignin on the fiber
was detected by scanning electron microscope and the thermal stability of the pulp sheets
assessed via viscosity and tensile strength tests, respectively. Thermal treatments were conducted
at high temperature (225 °C) in the presence of water vapor (volume fraction 1 and 75%).
Scanning electron imaging revealed distinct deposition of lignin onto the fiber surface. The lignin
treated pulp showed higher stability after the refining and thermal treatments. Both viscosity and
tensile strength values were higher than in the case of the fully bleached kraft pulp.
Key words:

37. TMP mill process water by flotation – analysis of the foam fraction

Authors: Jiayi Yang
Corresponding author: Jiayi Yang
Affiliation: Mid Sweden University
E-mail: jiayi.yang@miun.se
Abstract:
Improved by the technological development of thermomechanical pulp (TMP) industry, the specific fresh water consumption has been considerably cut down in the last few decades. This has rendered in that up to 5% wood substance are released into the process water circulation. Hydrophilic as well as lipophilic wood substances are circulated in the system and negatively affect the manufacturing process and the final product. In this study, a selective separation of detrimental lipophilic extractives from TMP process water by induced air flotation (IAF) was conducted, with additions of dodecyl trimethylammonium chloride (DTAC) as foaming agent to increase the separation. Extraction of the foam fraction with methyl tert-butyl ether (MTBE) was performed and the lipophilic extractives were analyzed by gas chromatography. The results indicate that the foam fraction contained approximately 1000 mg/L extractives, which were comprised of 83% lipophilic wood components; fatty and resin acids, sterols, triglycerides. Small amounts of lignin and residual DTAC were also detected.
Key words: