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  • 1.
    Anukam, Anthony
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Famewo, Elizabeth Bosede
    University of Fort Hare, South Africa.
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Improving the understanding of the bonding mechanism of primary components of biomass pellets through the use of advanced analytical instruments2019In: Journal of wood chemistry and technology, ISSN 0277-3813, E-ISSN 1532-2319, p. 1-18Article in journal (Refereed)
    Abstract [en]

    Previous studies have attempted to explain forces holding particles together in densified biomass pellets using theories of forces of attraction between solid particles, forces of adhesion and cohesion, solid bridges and mechanical interlocking bonds including interfacial forces and capillary pressure. This study investigated the bonding mechanism of primary biomass components in densified pellets through the use of advanced analytical instruments able to go beyond what is visible to the naked eye. Data obtained were used to predict how primary biomass components combine to form pellets based on the theory of functional groups and the understanding of structural chemistry. Results showed that hydroxyl and carbonyl functional groups played key roles in helping to identify the type of forces acting between individual particles, at a molecular level. At a microscopic level, morphological examination of the pellet clearly showed solid bridges caused by intermolecular bonding from highly electronegative polar functional groups linked to cellulose and hemicellulose.

  • 2.
    Beiron, Jens
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Drifterfarenheter från ett superisolerat flerbostadshus: Kv SEGLET, Karlstad2010Report (Other academic)
    Abstract [en]

    Seglet är ett 12-vånings punkthus med 44 lägenheter beläget i Karlstad. Byggherre är Karlstads Bostads AB. Huset är byggt med mycket höga ambitioner när det gäller kvalitet och resurshushållning och togs i drift i börjanav 2007.

    Denna rapport redovisar klimatskalets egenskaper och funktion samt utformningen av installationssystemen för värme, ventilation och tappvatten.Rapporten beskriver också drifterfarenheterna från de första årens drift samt de förbättringsåtgärder som utförts.

    Seglets lösningar visar att energieffektivisering och inneklimat kan gå hand ihand. Konceptet med en enkel förvärmning av tilluften löser två problem. Dels kan tilluften tillföras lägenheten utan risk för drag och dels saknar det FTX-systemets nackdelar med utökat servicebehov för filterbyten och ökad elanvändning för tilluftsfläkten. Det välisolerade och täta klimatskalet ger en komfortabel inomhusmiljö. Den befarade risken med höga rumstemperaturer sommartid har inte besannats. Tack vare genomtänkta fönsterplaceringar med solskyddsglas där så är befogat samt goda möjligheter till effektiv vädring har lägenheterna samma temperaturnivå sommartid som motsvarande lägenheter i normalisolerade byggnader. Byggnaden är mycket resurseffektiv med låga förbrukningstal på både energi och vatten. Då största delen av värmebehovet täcks med fjärrvärme står sig byggnaden mycket väl i en jämförande miljöbedömning.

    Nyckeltal för klimatskal och energianvändning

    Medelvärde för klimatskalets värmeisolering, Um, W/m2,K ca 0,21

    Luftläckage, läckflöde vid provtryckning till 50 Pa, l/s,m2Aomg 0,13

    Specifik energianvändning, kWh/m2,år 58

     

     

  • 3.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kartläggning och nulägesbeskrivning av pelletskedjan2011Report (Other academic)
  • 4.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Lösningarna finns! Är pelletsproducenterna medvetna om problemen?2011In: Bioenergi: utmaningar och möjligheter / [ed] Delin, Karin, Persson, Lars, Wikström, Per-Arne, Gävle: Region Gävleborg , 2011, p. 25-29Chapter in book (Other academic)
    Abstract [sv]

    Sverige är inte längre världsledande som pelletsproducent. USA producerar allra mest pellets i världen. Kanada och Ryssland producerar också allt mer pellets. Ingen av dessa länder har någon omfattande inhemsk konsumtion. I stort sett all pellets exporteras och det sker huvudsakligen till Europa. Sannolikt kommer det att leda till att priset på pellets i Europa sjunker, med följd att lönsamheten för svenska pelletsproducenter minskar.

  • 5.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Varför får inte villaägaren driva kvalitetsutvecklingen på bränslepellets?2011In: Bioenergi: utmaningar och möjligheter / [ed] K. Delin, L. Persson, P.-A. Wikström, Gävle: Region Gävleborg , 2011, p. 31-33Chapter in book (Other academic)
  • 6.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Nordgren, Daniel
    Innventia, Box 5604, SE-11486 Stockholm, Sweden.
    Tomani, Per
    Innventia, Box 5604, SE-11486 Stockholm, Sweden.
    The effects of kraft lignin additives on wood fuel pellet quality, energy use and shelf life2013In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 112, no 0, p. 64-69Article in journal (Refereed)
    Abstract [en]

    In 2011, the total consumption of pellets in Sweden amounted to 1.9 million tons, which represents an energy value of 9 TWh. The pellets are used in large-scale as well as in small-scale applications, and increased demands on pellet quality are likely to force pellet producers to improve on the pellet properties. One way of increasing pellet quality is by using additives. The purpose of this article, therefore, is to examine kraft lignin as an additive. Pelletswere produced in a small industrial pellet press located at KarlstadUniversity, Karlstad, Sweden, and 1–4% of kraft lignin was added to the pellets. The results indicate that the addition of an increased amount of kraft lignin to the pellets increases their mechanical durability and their lengths. The results also indicate that dry kraft lignin yields pellets with higher durability as compared to wet kraft lignin. The energy demand was unaffected by the increased use of kraft lignin. The general results presented in this paper are useful for producers of lignin, pellet producers and end-users of pellets, who are interested in developing their products and/or improving the production processes.

  • 7.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodesson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Tillsatser som kvalitetshöjare för pellets2011Report (Other academic)
  • 8.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Ståhl, Magnus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The amount of dust and rejects as well as the electricity consumption during production decreases with the use of adequate additives2017Conference paper (Other academic)
  • 9.
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013). Environmental and Energy Systems.
    Towards Understanding the Pelletizing Process of Biomass: Perspectives on Energy Efficiency and Pelletability of Pure Substances2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The use of fossil resources has to decrease and the use of renewable resources has to increase significantly to mitigate the climate change. In this change towards more renewable resources, biomasses will play an important role, both for energy use and for products. Thus, the utilization of biomasses must be optimized, both linked to which biomass species that are used, as well as the actual production processes. This thesis relates to the production of lignocellulosic biomass pellets, with the purpose to increase the understanding of how a pellet process can be improved. 

    There are many benefits to pelletize the biomass, such as increased density, more economical transports solutions and increased doseability. However, there is a lack of knowledge on how different biomass species affect the actual pelletizing. This causes pellet producers to strive for a feedstock with a chemical composition that is as uniform as possible, which reduces the possibility of increasing intake of, for example, seasonal or residual products of other kinds.

    If pellet producers can handle, predict and combine different biomaterials over time without stopping the production, new ways of acquiring raw materials for production would be possible. This will be important for future pellet producers, as the general use of biomasses will increase, so will the competition of the raw material. It will also be of importance in developing countries, which have a greater variation in wood species than today's large pellets producing countries. 

    This work has been focused on understanding biomasses pelletability, and the method has been to start with components such as, cellulose, hemicellulose, lignin etc. Results shows that there is a significant difference between the hemicelluloses, xylan and glucomannan, in terms of pelletability. During pelletizing, xylan changes its form, generates hard pellets and, correlated to pelletability, xylan are affected by actual moisture content or added water to the process. Glucomannan, however, shows the opposite, a low impact on pelletability and a minimal impact from water during the pelletizing process. A difference that can explain the difference in pelletability, between hardwood and softwood. 

    Solutions to improve the pelletizing process have also been studied. One result is that adding oxidized starch additive, reduces the energy consumption in the pelletizer and increasing the durability of the pellets, more than native starches. Another result is that a two-stage drying technique, reduces the heat power consumption per tonne of dried materialand at the same time increases the drying capacity. Also, the possibilities for a pellet producer to handle, predict and combine different biomaterials has been studied. Presented results show howbiomasses from Zambia can be used as an single resource or in different resources combinations in a pellet production. 

    Finally, a recommendation to pellet researchers to include the cellulose material, Avicel, in single pellet studies. By using the same reference material, the methods can be normalized and the pelletability of biomaterials can be validated in a new way. This step would develop the research in the field, and the possibility of increased use of biomass towards the use of more renewable resources in pellet production.

  • 10.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Study of Drying Processes and Air Flow Distribution in a Drying Cabinet Using an Infrared Camera2009In: Proceedings of the 4th Nordic Drying Conference NDC2009 / [ed] Trygve M. Eikevik, Odilio Alves-Filho, Trondheim: Norwegian University of Science and Technology, SINTEF , 2009Conference paper (Refereed)
  • 11.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Renström, Roger
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Pneumatic dryer as a second step in a two step drying technique2013In: Sixth Nordic Drying Conference NDC 2013, 2013Conference paper (Refereed)
  • 12.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The potential in using two step drying techniques for improving energy efficiency and increasing the drying capacity in fuel pellet industries2012In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 31, no 15Article in journal (Other academic)
  • 13.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Renström, Roger
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    The Potential of Using Two-Step Drying Techniques for Improving Energy Efficiency and Increasing Drying Capacity in Fuel Pellet Industries2013In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 31, no 15, p. 1863-1870Article in journal (Refereed)
    Abstract [en]

    The use of wood fuel pellets has increased worldwide in recent years, and pellet producers conclude that the lack of drying capacity is a barrier to increased production. In this study, we develop a concept of two different dryers called the two-step drying technique. The aim is to show the potential for increasing the drying capacity and improving energy efficiency when introducing a second dryer into the pellet plant. The study is theoretical and based on an industrial packed moving bed dryer. It shows that the drying capacity increased by 22% when a pneumatic second dryer was used.

  • 14.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Ståhl, Magnus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Granström, Karin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Romlin, Carl
    Drinor AB, Karlstad.
    Thelander, Alexander
    Drinor AB, Karlstad,.
    The Potential for a Pellet Plant to Become a Biorefinery2019In: Processes, ISSN 2227-9717, Vol. 7, no 4, p. 1-11, article id 233Article in journal (Refereed)
    Abstract [en]

    The use of bioenergy has increased globally in recent years, as has the utilization of biomaterials for various new product solutions through various biorefinery concepts. In this study, we introduce the concept of using a mechanical dewatering press in combination with thermal drying in a pellet plant. The purpose of the study is to increase the understanding of the effects a mechanical dewatering press has in a pellet production chain and investigate whether a pellet plant could thus become a biorefinery. The evaluations in this study are based on industrial data and initial tests at the university. The results show that the concept of using the mechanical dewatering press together with a packed moving bed dryer reduces energy use by 50%, compared to using only a packed moving bed dryer. The press water could be used as a raw material for biogas, bioplastics, and biohydrogen. Hence, this study points out the possibilities of a pellet plant increasing the efficiency of the drying step, while moving towards becoming a biorefinery.

  • 15.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Henriksson, Gunnar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Effects of moisture content during densification of biomass pellets, focusing on polysaccharide substances2019In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 122, p. 322-330Article in journal (Refereed)
    Abstract [en]

    In this study, we pelletized four different pure polysaccharides represented cellulose - Avicel, hemicelluloses - locus bean gum mannan and beech xylan and other polysaccharides - apple pectin, and three woods - pine, spruce and beech. All were pelletized at 100° in a single pellet press unit with different level of moisture content from 0 to 15%. The maximal friction force and work required for compression and friction was analyzed together with the pellet density and hardness. The results showed that xylan pellets completely changed in color at 10% moisture content, and this also occurred to some extent with pectin pellets. The color of both Avicel and locus bean gum pellets were not affected at all. During compression, the results showed that water does not affect compression up to 5 kN, while above 5 kN water decreases the energy need for densification of Avicel, locus bean gum and woods. Above 5 kN the energy needs for compressing xylan and pectin increases with increased moisture content. The hardest pellets were produced from Avicel, while locus bean gum produced the weakest pellets. The study concludes that there is a significant difference in how water affects the two hemicelluloses, glucomannan and xylan, during densification.

  • 16.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Henriksson, Gunnar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Pelletizing pure biomass substances to investigate the mechanical properties and bonding mechanisms2018In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, no 1, p. 1202-1222Article in journal (Refereed)
    Abstract [en]

    Solid fuel for heating is an important product, and for sustainability reasons, it is important to replace nonrenewable fuels with renewable resources. This entails that the raw material base for pellet production has to increase. A broader spectrum of materials for pelleting involves variation in biomass substances. This variation, due to lack of knowledge, limits the possibilities to increase the pellet production using new raw materials. In this study, pellets were produced with a single pellet press from 16 different pure biomass substances representing cellulose, hemicellulose, other polysaccharides, protein, lignin, and extractives, and five different wood species, representing softwoods and hardwoods. All pellets were analyzed for the work required for compression and friction, maximum force needed to overcome the backpressure, pellet hardness, solid density, and moisture uptake. The results showed that the hardest pellets were produced from the group of celluloses, followed by rice xylan and larch arbinogalactan. The weakest pellets were from the group of mannans. Conclusions are that the flexible polysaccharides have a greater impact on the pelletizing process than previously known, and that the differences between xylan and glucomannan may explain the difference in the behavior of pelletizing softwoods and hardwoods.

  • 17.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Technology and Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013). Environmental and Energy Systems.
    Linden, Pär
    Wallenberg Wood Science Centre, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.
    Henriksson, Gunnar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Compression of Biomass Substances—A Study on Springback Effects and Color Formation in Pellet Manufacture2019In: Applied Science, E-ISSN 2076-3417, Vol. 9, no 20, article id 4302Article in journal (Refereed)
    Abstract [en]

    In order to increase the use of a variated raw material base for pellet production with a maintained density level, knowledge of the biomaterials’ ability to counteract any springback effects is essential. In this study, the springback effects were investigated for single press produced pellets from cellulose, hemicelluloses, pectin, and two woods at different moisture contents. The change in pellet coloring was also tested through a spectrophotometer for both xylan and carboxymethyl cellulose (CMC) pellets. The results show that the density of xylan pellets is much higher than glucomannan, for both green and cured pellets, and that the length of the pellets, as well as springback contribution, differ between the hemicelluloses. The study also presents results showing that both xylan and CMC pellets have a mutually identical spectrum and that the changes in the structure of xylan are not only related to moisture content, but are also pressure-related. The study also postulates that the color difference of the xylan pellets is a result of physical changes in the structure, as opposed to being of a chemical nature.

  • 18.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Drying of Grain2011In: 5th Nordic Drying Conference / [ed] Alves-Filho, Odilio, Eikevik, Trygve, & Alves, Svetlana, Trondheim: SINTEF , 2011Conference paper (Refereed)
  • 19.
    Granström, Karin
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Williams, Helen
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Sandberg, Maria
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The importance of a holistic perspective when investigating agricultural products as additives in sustainable pellets development2012Conference paper (Refereed)
  • 20.
    Henriksson, Lisa
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Andersson, Simon
    Emerging Cooking Solutions Sweden AB.
    Ohlson, Mattias
    Emerging Cooking Solutions Sweden AB.
    Bioresources for Sustainable Pellet Production in Zambia: Twelve Biomasses Pelletized at Different Moisture Content2019In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 14, no 2, p. 2550-2575Article in journal (Refereed)
    Abstract [en]

    The use of charcoal and firewood for cooking is common in Zambia,and its utilization is suchthat the deforestation rate is high, energy utilization is low, and unfavorable cooking methods lead to high death rates due to indoor air pollution mainly from particulate matter and carbon monoxide.Byusing an alternative cooking method, such as pellet stoves, it is possible to offer a sustainable solution, provided that sustainable pelletproduction can be achieved. In this study, 12different available biomaterials were pelletizedina single pellet unitto investigate their availability as raw materials for pellet production in Zambia. The study showedthat sicklebush and pigeon pea generatedthe same pelleting properties correlated withcompression and frictionand that both materials showedlow moisture uptake. The study also identifiedtwo groups of materials that broadenedthe raw material base and helpedto achieve sustainable pellet production.Group 1consisted of materials with equal pelletingabilities (miombo, peanut shell, pigeon pea,and sicklebush) andGroup 2 consistedof materialsthat showed low impact of varying moisture content(eucalyptus, miombo, peanut shell, pigeon pea, and sicklebush). The hardest pellet was made from Tephrosia, which wasfollowed by Gliricidia.

  • 21.
    Renström, Roger
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Nilsson, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences.
    Lestelius, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Chemical Engineering. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences, Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Materials Science.
    Moons, Ellen
    Karlstad University, Faculty of Technology and Science, Department of Physics and Electrical Engineering.
    Stawreberg, Lena
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The drying process from a product perspective2013Conference paper (Refereed)
  • 22.
    Sandberg, Maria
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Miljöaspekter på produktion och lagring av träpellets2011Report (Other academic)
  • 23.
    Ståhl, Magnus
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Additives for wood fuel pellet production - A win, win, win situation2016Conference paper (Other academic)
    Abstract [en]

    The production and use of wood-fuel pellets, preferably made from sawdust or shavings, have increased significantly worldwide in recent years. If wood-fuel pellets should continue to be a successful biofuel at the energy market there are several factors to take into consideration. The pellet production industry already tries to reduce the production cost, since it is a low margin business. Further, it tries to produce pellets from a broader raw material base and at the same time satisfy the customer requirements while producing a sustainable product. The wood fuel pellet industry has the possibility to meet all these criteria; however, it also has the potential for improvements.

    This work focuses on energy efficiency, technical aspects and environmental factors, i.e., the electricity consumption, the physical and mechanical properties of the pellets, and the CO

    2 equivalent emitted during production, respectively. 20 various additives, with an admixture of up to 2 % (wt.), have been tested during wood fuel pellet production at Karlstad University. This work presents the benefits of using different additives in pellet production and the cost associated with different additives. The results shows that additive from the sea and from farmlands (algae, rape seed cake and grass) decrease the energy use in the pellet press but unfortunately also decrease the durability. Additives from wood (resins, lignin) and molasses increases the durability of the pellet but shows almost no or little change in electricity consumption. However, using starch grades, white sugar or spent sulphite liquor as an additive increases the mechanical properties while it decreases both the electricity consumption and the climate impact, hence a win-win-win situation. To justify the use of additives from a climate impact perspective in regions with an OECD European electricity mix or the Swedish electricity mix, the usage of additives from the rest products where the CO2 equivalent emissions are allocated to the main product are crucial.

    In conclusion, it is necessary to do research that systematically investigates the consequences of using additives for wood fuel pellets to continuously be a successful biofuel at the energy market

  • 24.
    Ståhl, Magnus
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Research Experience From The Use Of Different Additives In Wood-Fuel Pellet Production2017In: International Journal of Energy Production and Management, ISSN 2056-3272, E-ISSN 2056-3280, Vol. 2, no 3, p. 288-293Article in journal (Refereed)
    Abstract [en]

    The use of wood-fuel pellets has increased signi cantly worldwide in recent years, especially in the United Kingdom. If wood-fuel pellets should continue to be a successful biofuel at the energy market, the pellet production industry has to reduce the production cost, since it is a low-margin business. Further, improved pellets regarding storability and strength of the pellets are crucial to manage the overseas transportation that causes material losses. In addition, the industry tries to produce pellets from a broader raw material base and at the same time satisfy the customer requirements while produc- ing a sustainable product. The wood-fuel pellet industry has the possibility to meet all these criteria; however, it also has the potential for improvements. Using additives in pellet production is one way to meet the criteria. In conclusion, it is necessary to do the research that systematically investigates the consequences of using additives for wood-fuel pellets, and this work presents a compilation of results and experiences from more than 20 different additive studies and the test bed for pellet produc- tion research at Karlstad University– a pellet production unit adapted for additives studies. Additives, with an admixture of up to 2% (wt.), have been tested in the NewDeP (New Development for Pellet Technology) pilot plant for pellet production at Karlstad University. The research has focused on the electricity consumption, the physical and mechanical properties of the pellets, and the CO2 equivalents emitted during production. The results showed that the additives Wetland grass, Algae, Turpentine and Lignin decreased the electricity consumption in the pellet press but unfortunately also decreased the durability. The additives Resins, Molasses, White sugar, Native potato starch and Oxidized potato starch increased the durability of the pellet but showed almost no change in the electricity consumption. However, Oxidized corn starch, Spent sulphite liquor and Native wheat starch as additives increased the mechanical properties while it decreases both the electricity consumption and the climate impact, hence a Win-Win-Win situation. 

  • 25.
    Ståhl, Magnus
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berghel, Jonas
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Frodeson, Stefan
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Granström, Karin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Effects on Pellet Properties and Energy Use When Starch Is Added in the Wood-Fuel Pelletizing Process2012In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 26, no 3, p. 1937-1945Article in journal (Refereed)
    Abstract [en]

    The production and use of wood-fuel pellets have increased significantly worldwide in recent years. The increased use of biomaterials has resulted in higher raw material prices, and there are no signs that indicate a decrease in raw material competition. Additives can be used for different purposes. Partly, they are used to facilitate the use of new raw materials to increase the raw material base, and partly, they are used to decrease the energy use in the pelletizing process. They are also used to increase durability or shelf life. Consequently, it is necessary to do research that systematically investigates the consequences of using additives. In this work, it is investigated how various percentages of different kinds of starch influence pellet properties, including shelf life and energy use in the pelletizing process. Four different starch grades were used: native wheat starch, oxidized corn starch, native potato starch, and oxidized potato starch. The pellets were produced in a small industrial pellet press located at Karlstad University, Karlstad, Sweden. The result shows that starch increases the durability of the pellets. Oxidized starches increase the durability more than native starches, and the best results were obtained by adding oxidized corn starch. The durability did not decrease with storage time when the pellets were stored indoors during 7 months. The oxidation process was not consistently altered by the addition of starch. The energy consumption of the pellet press decreases when starch is added. Again, the oxidized corn starch showed the best result; when 2.8% of corn starch was added, the average energy consumption was reduced by 14%

  • 26.
    Ståhl, Magnus
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Energy reduction in wood-fuel pellet production2013In: Forest bioenergy review, ISSN 2045-8614, Vol. 4, no 19, p. 6-Article in journal (Other academic)
  • 27.
    Ståhl, Magnus
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Olsson, Stefan
    Stora Enso.
    Using Secondary Pea Starch in Full-Scale Wood Fuel Pellet Production Decreases the Use of Steam Conditioning2019In: World Sustainable Energy Days 2019: European Pellet Conference, 2019Conference paper (Refereed)
1 - 27 of 27
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