Change search
Link to record
Permanent link

Direct link
BETA
Frodeson, Stefan, UniversitetsadjunktORCID iD iconorcid.org/0000-0003-0446-4251
Alternative names
Biography [eng]

Currently, I conduct doctoral studies in my field of research, wood pelleting and the ability to use additives that lead to a broader raw material base and increased utilization of waste products. Current research is about understanding the chemical composition of wood and the role of pure wood substances during the densification process.

I’m a member of the research group NewDeP, which is a part of the research environment Pro2BE. My research is mainly based on laboratory studies in single pellet levels and in pilot scale, but studies in full-scale applications are also conducted.

Biography [swe]

Jag är forskarstuderande inom området pelletering av biomaterial, ett arbete som sker inom forskargruppen NewDeP, som är en del i forskningsmiljön Pro2BE. Min pågående forskning fokuserar på ökad förståelse kring hur olika träsubstanser påverkar och påverkas av komprimeringssteget i en pelletspress. 

Publications (10 of 26) Show all publications
Henriksson, L., Frodeson, S., Berghel, J., Andersson, S. & Ohlson, M. (2019). Bioresources for Sustainable Pellet Production in Zambia: Twelve Biomasses Pelletized at Different Moisture Content. BioResources, 14(2), 2550-2575
Open this publication in new window or tab >>Bioresources for Sustainable Pellet Production in Zambia: Twelve Biomasses Pelletized at Different Moisture Content
Show others...
2019 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 14, no 2, p. 2550-2575Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
North Carolina: North Carolina State University, 2019
Keywords
Biomass pellets, Single pellet press, Densification, Backpressure, Chemical composition
National Category
Paper, Pulp and Fiber Technology Energy Systems Other Environmental Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-71412 (URN)10.15376/biores.14.2.2550-2575 (DOI)000466449000010 ()
Available from: 2019-03-02 Created: 2019-03-02 Last updated: 2019-10-30Bibliographically approved
Frodeson, S., Henriksson, G. & Berghel, J. (2019). Effects of moisture content during densification of biomass pellets, focusing on polysaccharide substances. Biomass and Bioenergy, 122, 322-330
Open this publication in new window or tab >>Effects of moisture content during densification of biomass pellets, focusing on polysaccharide substances
2019 (English)In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 122, p. 322-330Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Wood pellets, densification, cellulose, hemicellulose, xylan, glucomannan
National Category
Paper, Pulp and Fiber Technology Bioenergy Energy Systems
Research subject
Environmental and Energy Systems; Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-71411 (URN)10.1016/j.biombioe.2019.01.048 (DOI)000459461800034 ()
Note

APC betald 2019.

Available from: 2019-03-02 Created: 2019-03-02 Last updated: 2019-10-30Bibliographically approved
Anukam, A., Berghel, J., Famewo, E. B. & Frodeson, S. (2019). Improving the understanding of the bonding mechanism of primary components of biomass pellets through the use of advanced analytical instruments. Journal of wood chemistry and technology, 1-18
Open this publication in new window or tab >>Improving the understanding of the bonding mechanism of primary components of biomass pellets through the use of advanced analytical instruments
2019 (English)In: Journal of wood chemistry and technology, ISSN 0277-3813, E-ISSN 1532-2319, p. 1-18Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Taylor & Francis Group, 2019
Keywords
Biomass pelleting, bonding mechanism, functional groups, primary components, structural chemistry
National Category
Chemical Engineering
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-74768 (URN)10.1080/02773813.2019.1652324 (DOI)000482719600001 ()
Available from: 2019-09-16 Created: 2019-09-16 Last updated: 2019-09-23Bibliographically approved
Frodeson, S., Berghel, J., Ståhl, M., Granström, K., Romlin, C. & Thelander, A. (2019). The Potential for a Pellet Plant to Become a Biorefinery. Processes, 7(4), 1-11, Article ID 233.
Open this publication in new window or tab >>The Potential for a Pellet Plant to Become a Biorefinery
Show others...
2019 (English)In: Processes, ISSN 2227-9717, Vol. 7, no 4, p. 1-11, article id 233Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
Basel: MDPI, 2019
Keywords
Energy efficiency, wood pellet production, drying, biorefinery, bioplastics, mechanical dewatering
National Category
Energy Systems
Research subject
Chemistry
Identifiers
urn:nbn:se:kau:diva-72418 (URN)10.3390/pr7040233 (DOI)000467771400056 ()2-s2.0-85067518721 (Scopus ID)
Note

Funding: Swedish Agency for Economic and Regional Growth through the project FOSBE

Available from: 2019-06-11 Created: 2019-06-11 Last updated: 2019-10-14Bibliographically approved
Frodeson, S. (2019). Towards Understanding the Pelletizing Process of Biomass: Perspectives on Energy Efficiency and Pelletability of Pure Substances. (Doctoral dissertation). Karlstad: Karlstads universitet
Open this publication in new window or tab >>Towards Understanding the Pelletizing Process of Biomass: Perspectives on Energy Efficiency and Pelletability of Pure Substances
2019 (English)Doctoral 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.

Abstract [sv]

För att begränsa klimatpåverkan måste användandet av fossila resurser minska till förmån för förnyelsebara. In denna omställning är och kommer biomassa att bli en mycket viktigresurs att använda tillenergi samt olika produkter. Detta innebär att det är viktigt att både användningen och hanteringen sker resurs- och energieffektivt. Den här avhandlingen handlar om att pelletera lignocellulosisk biomassa med motivet att energieffektivisera pelletsprocessen, samt öka kunskapen om olika biomassors pelleterbarhet. 

Det finns många fördelar med att pelletera biomassa, såsom att produkten blir doserbar, lättare att lagra samt att den blir billigare att transporteratack vare högre densitet. Men olika biomassor har olika egenskaper beroende på deras kemiska uppbyggnad, och idag är kunskapen begränsad kring vad som påverkar pelleterbarheten i olika biomassor. Dettamedför att pelletsproduktionen eftersträvarsmå variationer i inkommande råmaterial såsom att bara använda färsk gran, bara lövträd eller en specifik mix. Att förstå och kunna hantera olika biomassors pelleterbarhet skulle innebära att pelletsproducenter kan nyttja ett varierat inflöde, utan att stoppa produktionen. Vilket kommer bli viktigt när omställningen mot mer förnyelsebart ökar konkurrensen om råvaran. En annan aspekt är ett ökat användande av pellets i utvecklingsländer, vilka många har en mycket större variation i träslag än dagens stora pelletsproducerande länder. 

Arbetet har inriktats på att förstå hur olika biomaterial påverkar pelleterbarheten. Metoden för detta har varit att utgå från komponenter i biomassan tex. cellulosa, hemicellulosa, lignin m.m. och bygga kunskap därifrån. Resultatet visar att hemicellulosans (i huvudsak xylan och glucomannan) påverkan på pelleterbarhet är större än vad som tidigare varit känt. Xylan under kompression påverkas genom att ändra form vilket resulterar i hårda pellets och starka bindningar, samt att dess påverkan av tillsatt vatten i processen är stor. Glucomannan visar på motsatsen, låg påverkan på pelleterbarhet samt att dess inverkan av tillsatt vatten är liten. Denna skillnad kan förklara olikheterna i att pelletera löv- och barrträd, eftersom xylan är huvudsakliga hemicellulosan i lövträd medan glucomannan är det i barrträd. 

Avhandlingen tar även upp hur pelletsprocessens kan effektiviseras. Ett resultat är att oxiderad stärkelse som additiv reducerar energiåtgången i pelletspressen mer än icke oxiderad stärkelse, samtidigt som pelletens hållfasthet förbättras. Ett annat resultat är en tvåstegs-torkteknik som energieffektiviserar torkprocessen samtidigt som torkkapaciteten ökar. Även att kunna hantera olika biomassors pelleterbarhet presenteras, inriktat på hur olika biomassor från Zambia, kan användas för pelletsproduktion.

Slutligen finns en rekommendation till pelletsforskare om att inkludera cellulosamaterialet Avicel, i singelpellets-studier. Om alla använder samma referensmaterial, kan metoderna normaliseras och biomassors pelleterbarhet valideras på ett nytt och bättre sätt. Något som utvecklar både forskningen och omställning mot ett ökat nyttjande av förnyelsebara resurser. 

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 transformation, biomasses will play an important role, and the utilization of biomasses must be optimized. 

As a pelletized product the biomass gets increased density, are more economical to transport and the doseability of the product are increased. Thus, as pellets the possibilities to add biomasses in variated application will be both more energy efficient and can be optimized in a better way. Today, there is a lack of knowledge how different biomass species affect the actual pelletizing, and this causes pellet producers to strive for a feedstock with a chemical composition that is as uniform as possible. 

In this thesis, it is shown how the pelletizing process can be improved and how a wider utilization of biomasses can be used by an increased understanding about the pelletability when pelletizing pure substances. Results shows that there is a significant difference between the substances within the hemicelluloses. A difference that can explain the difference in pelletability, between hardwood and softwood.

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 transformation, biomasses will play an important role, and the utilization of biomasses must be optimized. 

As a pelletized product the biomass gets increased density, are more economical to transport and the doseability of the product are increased. Thus, as pellets the possibilities to add biomasses in variated application will be both more energy efficient and can be optimized in a better way. Today, there is a lack of knowledge 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. 

This thesis has been focused on understanding biomasses pelletability, and the method has been to start with pure substance such as, cellulose, hemicellulose, lignin etc. In total, thirty-eight different material are included, divided into seventeen biomasses and twenty-one pure substances. Results shows that there is a significant difference between the components within the hemicelluloses, xylan and glucomannan. A difference that can explain the difference in pelletability, between hardwood and softwood.

Also, how the pelletizing process can be more energy efficient, with increased drying capacity and increased pellet durability are presented. As well as there are solutions to combined and used a biomass flow as single resources or in combinations without stopping the production line. 

Place, publisher, year, edition, pages
Karlstad: Karlstads universitet, 2019. p. 70
Series
Karlstad University Studies, ISSN 1403-8099 ; 2019:32
Keywords
Pelletability, wood pellets, densification, chemical composition
National Category
Energy Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-75440 (URN)978-91-7867-057-4 (ISBN)978-91-7867-067-3 (ISBN)
Public defence
2019-12-05, 9C 203, Universitetsgatan 2, Karlstad, 09:00 (Swedish)
Opponent
Supervisors
Available from: 2019-11-15 Created: 2019-10-30 Last updated: 2019-11-15Bibliographically approved
Ståhl, M., Frodeson, S., Berghel, J. & Olsson, S. (2019). Using Secondary Pea Starch in Full-Scale Wood Fuel Pellet Production Decreases the Use of Steam Conditioning. In: World Sustainable Energy Days 2019: European Pellet Conference. Paper presented at World Sustainable Energy Days 2019/European Pellet Conference.
Open this publication in new window or tab >>Using Secondary Pea Starch in Full-Scale Wood Fuel Pellet Production Decreases the Use of Steam Conditioning
2019 (English)In: World Sustainable Energy Days 2019: European Pellet Conference, 2019Conference paper, Oral presentation only (Refereed)
National Category
Engineering and Technology
Research subject
Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-71435 (URN)
Conference
World Sustainable Energy Days 2019/European Pellet Conference
Available from: 2019-03-05 Created: 2019-03-05 Last updated: 2019-06-19Bibliographically approved
Frodeson, S., Henriksson, G. & Berghel, J. (2018). Pelletizing pure biomass substances to investigate the mechanical properties and bonding mechanisms. BioResources, 13(1), 1202-1222
Open this publication in new window or tab >>Pelletizing pure biomass substances to investigate the mechanical properties and bonding mechanisms
2018 (English)In: BioResources, ISSN 1930-2126, E-ISSN 1930-2126, Vol. 13, no 1, p. 1202-1222Article in journal (Refereed) Published
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.

Place, publisher, year, edition, pages
North Carolina State University, 2018
Keywords
Biomass pellets, Renewable energy, Single pellet press, Wood pellets, Biomass, Cellulose, Fuels, Hardwoods, Polysaccharides, Presses (machine tools), Softwoods, Wood, Bonding mechanism, Non-renewable fuels, Pellet hardness, Pellet production, Renewable energies, Renewable resource, Wood pellet, Pelletizing
National Category
Energy Systems Paper, Pulp and Fiber Technology
Research subject
Environmental and Energy Systems; Chemical Engineering
Identifiers
urn:nbn:se:kau:diva-66400 (URN)10.15376/biores.13.1.1202-1222 (DOI)000427790000089 ()2-s2.0-85041345528 (Scopus ID)
Available from: 2018-02-16 Created: 2018-02-16 Last updated: 2019-11-08
Ståhl, M., Berghel, J. & Frodeson, S. (2017). Research Experience From The Use Of Different Additives In Wood-Fuel Pellet Production. International Journal of Energy Production and Management, 2(3), 288-293
Open this publication in new window or tab >>Research Experience From The Use Of Different Additives In Wood-Fuel Pellet Production
2017 (English)In: International Journal of Energy Production and Management, ISSN 2056-3272, E-ISSN 2056-3280, Vol. 2, no 3, p. 288-293Article in journal (Refereed) Published
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. 

Place, publisher, year, edition, pages
WIT Press, 2017
Keywords
additives, CO2 equivalents, durability, electricity consumption, wood-fuel pellets
National Category
Energy Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-70043 (URN)10.2495/EQ-V2-N3-288-293 (DOI)
Available from: 2018-11-06 Created: 2018-11-06 Last updated: 2018-11-07Bibliographically approved
Berghel, J., Ståhl, M. & Frodeson, S. (2017). The amount of dust and rejects as well as the electricity consumption during production decreases with the use of adequate additives. In: : . Paper presented at International Biomass and Conference & Expo, Minneapolis, Minnesota, USA. 10-12 April 2017.
Open this publication in new window or tab >>The amount of dust and rejects as well as the electricity consumption during production decreases with the use of adequate additives
2017 (English)Conference paper, Oral presentation only (Other academic)
National Category
Energy Engineering
Research subject
Environmental and Energy Systems
Identifiers
urn:nbn:se:kau:diva-63905 (URN)
Conference
International Biomass and Conference & Expo, Minneapolis, Minnesota, USA. 10-12 April 2017
Available from: 2017-09-22 Created: 2017-09-22 Last updated: 2018-06-26Bibliographically approved
Ståhl, M., Berghel, J. & Frodeson, S. (2016). Additives for wood fuel pellet production - A win, win, win situation. In: : . Paper presented at 6th International Symposium "Energy challenges & mechanics - towards a big picture", Inverness, Scotland. 14-18 august 2016.
Open this publication in new window or tab >>Additives for wood fuel pellet production - A win, win, win situation
2016 (English)Conference paper, Oral presentation with published abstract (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

National Category
Energy Engineering Energy Systems Bioenergy
Identifiers
urn:nbn:se:kau:diva-63906 (URN)
Conference
6th International Symposium "Energy challenges & mechanics - towards a big picture", Inverness, Scotland. 14-18 august 2016
Available from: 2017-09-22 Created: 2017-09-22 Last updated: 2018-07-09Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-0446-4251

Search in DiVA

Show all publications