| 1. |
- Anukam, Anthony, et al.
(author)
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A review of the mechanism of bonding in densified biomass pellets
- 2021
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In: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 148
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Journal article (peer-reviewed)abstract
- The production of durable biomass pellets have always been challenged by several factors including the lack of understanding of the mechanism involved in how particles combine to form pellets under standard conditions of the pellet press. This is because contributing factors span several molecular, microscopic, and even nanoscopic levels as biomass undergoes pelleting. The characteristics of the bonds formed between the combining particles and their relevance to the quality of pellets remains vague, no matter how quality is defined. However, even though few researchers have attempted to explain the mechanism of bonding in densified biomass pellets using different theories, none of their hypotheses supports particle bonding from a structural chemistry perspective. There are still no clear explanations which consider the role of molecular structure and the interactions of substances as milled biomass undergo pelleting. In view of these arguments therefore, this review presents an in-depth analysis of a structural chemistry perspective of the mechanism of bonding and the use of additives in densified biomass pellets and helps identify research areas needed to facilitate better understanding of bonding in densified biomass pellets. The status of current research in biomass pelleting, types of materials suitable as additives and their structural characteristics, as well as the current technical specifications of using additives are also discussed.
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| 2. |
- Berghel, Jonas, 1966-, et al.
(author)
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A comparison of relevant data and results from single pellet press research is Mission Impossible : A review
- 2022
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In: Bioresource Technology Reports. - : Elsevier. - 2589-014X. ; 18
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Journal article (peer-reviewed)abstract
- A global increase in the wood fuel pellet market requires knowledge of new biomasses pelleting abilities. As large-scale industrial tests of new materials are costly, tests in e.g., a single pellet press (SPP) are desirable. SPPs have many different configurations and it typically produces one pellet at a time and can give results of its pelletability. This review has surveyed the research that has been carried out of SPPs to ascertain the feasibility of comparing their obtained data and the results. The results show that it is almost impossible to compare the data and results of the various different SPP studies, e.g., some information from the data used was missing, resulting in that only 27 out of 70 papers were comparable. One solution could be the introduction of a common SPP testing method using a determined set of data that enables a reference pellet to be produced in every study.
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| 3. |
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| 4. |
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| 5. |
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| 6. |
- Berghel, Jonas, 1966-, et al.
(author)
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Lösningarna finns! Är pelletsproducenterna medvetna om problemen?
- 2011
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In: Bioenergi. - Gävle : Region Gävleborg. - 9789163391262 ; , s. 25-29
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Book chapter (other academic/artistic)abstract
- 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.
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| 7. |
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| 8. |
- Berghel, Jonas, 1966-, et al.
(author)
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The effects of kraft lignin additives on wood fuel pellet quality, energy use and shelf life
- 2013
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In: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 112:0, s. 64-69
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Journal article (peer-reviewed)abstract
- 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.
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| 9. |
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| 10. |
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| 11. |
- Frodeson, Stefan, Universitetsadjunkt, 1968-, et al.
(author)
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Densification of Wood-Influence on Mechanical and Chemical Properties when 11 Naturally Occurring Substances in Wood Are Mixed with Beech and Pine
- 2021
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In: Energies. - : MDPI AG. - 1996-1073. ; 14:18
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Journal article (peer-reviewed)abstract
- The need to increase the use of renewable biomasses for energy supply, such as fuel pellets is significant. However, different types of biomasses have different mechanical properties to be pelletized, which entails a limitation in available raw materials for pellet producers. Within this study eleven different pure substances from biomasses were separately mixed with European beech and Scots pine, to identify its impact on the densification process. Beech and pine pellets were used as control materials against their corresponding pellets mixed with substances representing: cellulose, hemicelluloses, other polysaccharides, lignin, protein, and extractives. The mechanical properties were investigated as well as FT-IR and SEM analyses on the pellets. The results showed that the addition of the substances xylan and galactan created the hardest pellets for both pine and beech and that adding extractives to wood affects pine more than beech in relation to hardness. The FT-IR data could not provide clear explanations as to the variation in hardness and springback behavior through the identification of major functional groups in each pellet. It can be concluded that biomass residues rich in xylan and galactan increase pellet quality in terms of strength and durability without affecting the production process.
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| 12. |
- Frodeson, Stefan, Universitetsadjunkt, 1968-, et al.
(author)
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The Potential for a Pellet Plant to Become a Biorefinery
- 2019
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In: Processes. - Basel : MDPI. - 2227-9717. ; 7:4, s. 1-11
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Journal article (peer-reviewed)abstract
- 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.
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| 13. |
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| 14. |
- Kjeang, Are, 1952-, et al.
(author)
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Energy consulting services in the information age - literature review
- 2017
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In: Energy, Sustainability and Society. - : Springer Science and Business Media LLC. - 2192-0567. ; 7:1
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Research review (peer-reviewed)abstract
- The institution of energy consulting services is one of the several government instruments for improving the efficiency of energy usage in many European countries. Various forms of advice on energy issues are offered to households. In Sweden, there has been a drop in the number of households who avail of this service, even though it is offered independently, free of charge and easily accessible. Instead, Swedes have been increasingly seeking information on the Internet (websites, blogs and social media), which can be seen as both a challenge and an opportunity for the energy consulting service offered by Swedish municipalities. The aim of the literature study is to present an overview of current research in the area of energy consulting targeting households. This to identify central themes in the research front, identify knowledge gaps and discuss which challenges previous research emphasise for energy consulting services targeting households. The results show that research indicates that a measurement–feedback–communication strategy for households is necessary if one wishes to effect a change in consumer behaviour. Today, consumers expect more individualised information than before. Here, the three dimensions of sustainable development can be useful. Energy consulting is also better appreciated if it occurs in situ—at the customer’s home. How it can and should be developed in an increasingly digitalised world is a topic we think is vital for future research. Also, with sustainable development becoming increasingly important in this century, an interdisciplinary approach to energy consulting is strongly recommended by the authors of this paper.
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| 15. |
- Kjeang, Are, 1952-
(author)
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Goda råd är inte dyra! : Om personlig energirådgivning i ett alltmer digitaliserat samhälle
- 2018
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Licentiate thesis (other academic/artistic)abstract
- ”Nu är goda råd dyra”, heter det sedan gammalt i en svensk krissituation. I denna licentiatavhandling, vars rubrik kopplar till talesättet, behandlas svensk energirådgivnings utveckling och framtid. Forskning visar att i ett alltmer digitaliserat samhälle behöver energirådgivningen utvecklas för att bättre nå målgrupperna - hushåll, småföretag och organisationer. Digitala tjänster ger många möjligheter, men den viktiga personliga kontakten med energirådgivaren går inte att ersätta fullt ut. Med hjälp av fokusgrupper, intervjuer och samtal med energirådgivare, villaägare och enskilda experter har kunnat konstateras att den personligt genomförda rådgivningstjänsten är efterfrågad, angelägen och framgångsrik när byte av värmesystem, större ombyggnationer eller nybyggnationer är aktuellt. Att pröva idéer och lösningar, helst i hemmamiljön inför en ombyggnad, är uppskattad rådgivning. I samtalet, där inte enbart tekniska detaljer och lönsamhet diskuteras, kan alla i hushållet engageras. Energirådgivningen kan bli mer framgångsrik, men då krävs ett större kommunalt engagemang och en tydligare samverkan med andra statliga styrmedel. Hållbara råd kan alla få i Sverige idag och de goda råden är gratis! Med hjälp av dessa kan kanske kriser undvikas…
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| 16. |
- Klingberg, Eva, et al.
(author)
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A distinct gut microbiota composition in patients with ankylosing spondylitis is associated with increased levels of fecal calprotectin
- 2019
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In: Arthritis Research & Therapy. - : Springer Science and Business Media LLC. - 1478-6354 .- 1478-6362. ; 21:1
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Journal article (peer-reviewed)abstract
- Background Ankylosing spondylitis (AS) shares many characteristics with inflammatory bowel disease (IBD). Intestinal microbiota most likely plays an important role in the development of IBDs and may also be involved in the pathogenesis of AS. We aimed to define and compare the fecal microbiota composition in patients with AS, ulcerative colitis (UC), and healthy controls (HC) and to determine relationships between fecal microbiota, fecal calprotectin, and disease-related variables in AS. Methods Fecal microbiota composition was assessed with GA-map (TM) Dysbiosis Test (Genetic Analysis, Oslo, Norway), which also reports the degree of deviation of the microbiota composition compared with a healthy control population, a Dysbiosis Index (DI) score 1-5. The AS patients were assessed with questionnaires, back mobility tests, fecal calprotectin, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Results Totally, 150 patients with AS (55% men, median age 55.5 years, median BASDAI 3.2), 18 patients with UC (56% men, median age 30.5 years), and 17 HC (65% men, median age 22 years) were included. Principal component analysis showed highly separate clustering of fecal microbiota from the patients with AS, UC, and HC. Compared with HC, fecal microbiota in AS was characterized by a higher abundance of Proteobacteria, Enterobacteriaceae, Bacilli, Streptococcus species, and Actinobacteria, but lower abundance of Bacteroides and Lachnospiraceae. Further, fecal microbiota composition differed between patients with normal (<= 50 mg/kg, n = 57) and increased (>= 200 mg/kg, n = 36) fecal calprotectin. Patients with increased fecal calprotectin had lower abundance of bacteria with anti-inflammatory properties such as Faecalibacterium prausnitzii and Clostridium and higher abundance of the genus Streptococcus. No association was found between the fecal microbiota composition and HLAB27 status, disease activity, function, or medication. Dysbiosis (defined as DI >= 3) was found in 87% of AS patients. Conclusions Patients with AS have a distinct fecal microbiota signature, which is linked to fecal calprotectin levels, a marker of intestinal inflammation, but not to other clinical parameters. These findings suggest a local interplay between intestinal microbiota and gut inflammation in AS.
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| 17. |
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| 18. |
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| 19. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Additives for wood fuel pellet production - A win, win, win situation
- 2016
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Conference paper (other academic/artistic)abstract
- 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 CO2 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
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| 20. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Effects on Pellet Properties and Energy Use When Starch Is Added in the Wood-Fuel Pelletizing Process
- 2012
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In: Energy & Fuels. - Washington DC, Oxford UK : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 26:3, s. 1937-1945
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Journal article (peer-reviewed)abstract
- 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%
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| 21. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Energy efficiency, greenhouse gas emissions and durability when using additives in the wood fuel pellet chain
- 2016
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In: Fuel processing technology. - : Elsevier. - 0378-3820 .- 1873-7188. ; 152, s. 350-355
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Journal article (peer-reviewed)abstract
- The use of renewable resources for bioenergy should be performed to support sustainable development. Since the use of bioenergy has increased significantly worldwide in recent years and biomass is made of limited resources it must be used efficiently and with a low environmental impact The wood fuel pellet industry has the possibility to meet these criteria; however, it also has the potential for improvements. This work investigates how the additives, cornstarch and molasses, affect: the electricity consumption of the pellet press, the emission of Carbon dioxide equivalents (CO2 eq.) from the production of wood fuel pellets in three different countries with different emissions from electricity, the durability of the pellets and its effects on energy efficiency. The results show that pellet production is more energy efficient when additives are used, and that the amount of CO2 eq. increases with an increased use of additives. In countries with a low usage of fossil fuels for electricity production, the global warming impact gets higher due to the additives; while in countries that use a lot of fossil fuels to produce electricity, the global warming impact will be reduced because of the additives by up to 1%. The increased global warming impact from the additives can be balanced by the decrease in the reduced amount of rejected material within the production. That is because the durability of the pellets increases with an increasing amount of additive.
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| 22. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Energy Efficient Pilot-Scale Production of Wood Fuel Pellets made from a Raw Material Mix Including Sawdust and Rapeseed Cake
- 2011
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In: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 35:12, s. 4849-4854
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Journal article (peer-reviewed)abstract
- Presently, most fuel pellets are made from sawdust or shavings. In Sweden, these materials are used to the maximum extent. As the demand for pellets increases, the supply of sawdust will be insufficient and other raw materials or mixes of raw materials will be used. This work investigates sawdust mixed with rapeseed cake. The latter is a residual product from the production of chemically unmodified oil refined from cold-pressed rape oil. At the Department of Energy, Environmental and Building Technology at Karlstad University, Sweden, a complete pilot-scale pellet production unit is located. The pellets are produced and tested for mechanical durability, length, bulk density and moisture content according to the Swedish Standard for pellets. During production, the load current, the die pressure and the die temperature were measured along with other parameters. The main purpose was to examine how the mixture of rapeseed cake and pine sawdust affected the energy consumption of the pelletising machine and mechanical durability of mixed fuel pellets. The results show that the energy consumption decreased and the amount of fines increased with increasing rapeseed cake in the wood fuel pellets. These results indicate that we must compromise between a decrease in the use of energy and a decrease in durability.
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| 23. |
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| 24. |
- Ståhl, Magnus, 1973-
(author)
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Energy reduction in wood fuel pellet production : Verringerung des Energieverbrauchs bei der Produktion von Holzpellets
- 2012
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In: 12th Pellets Industry Forum Proceedings. - Pforzheim, Germany : Solar Promotion. ; , s. 85-90
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Conference paper (peer-reviewed)abstract
- The wood fuel pellet industry demands energy efficient solutions for their production since these not only save energy but also money. One way of achieving this is to use additives. Choosing the right additive can save money but also increase the quality of the pellets, a win win situation. In this work, it is investigated how different kind of additives affect the energy use of the pelletizing equipment and also how it affects the durability of pellets. The best results were achieved using oxidized cornstarch as an additive during pellet production, it not only decreases the energy used the most but also produce the pellets with highest durability.
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| 25. |
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| 26. |
- Ståhl, Magnus, 1973-
(author)
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Improving Wood Fuel Pellets for Household Use : Perspectives on Quality, Efficiency and Environment
- 2008
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Doctoral thesis (other academic/artistic)abstract
- Bioenergy is one of many contributors to reducing the use of fossil fuels in order to mitigate climate change by decreasing CO2-emissions, and the potential for biofuels are large. The wood fuel pellets are a refined biofuel made of sawdust, which is dried and compressed to achieve improved fuel and transportation properties. In 2007 the amount of wood fuel pellets used for heating purposes in Sweden was 1715000 tons. The aims of this work was: to examine the moisture content and emission of monoterpenes during the drying and pelletising steps of the pellets production (Paper I); to investigate how the recirculation of drying gases affects the energy efficiency of rotary dryers and how the energy efficiency is related to the capacity of the dryer. (Paper II); to analyse the causes of the problems encountered by household end-users of pellets and investigate whether an improved pellet quality standard could reduce these problems (Paper III); to investigate how the energy consumption of the pelletising machine and chosen pellet quality parameters were affected using an increased amount of rapeseed cake in wood fuel pellets (Paper IV); and to identify gaps of knowledge about wood fuel pellet technology and needs for further research on quality, environmental and health aspects throughout the wood fuel pellet chain, from sawdust to heat. (Paper V).
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| 27. |
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| 28. |
- Ståhl, Magnus, 1973-
(author)
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Longer Cooling Time and Lower Air Velocity is an Energy Efficient Way to Decrease the Amount of Fines During Pellet Production.
- 2020
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Conference paper (other academic/artistic)abstract
- Manufacturers of pellet equipment has asked for that the question of pellets cooling are investigated. The purpose is to examine how the temperature, cooling time and the velocity of the cooling air affects the durability of the pellets and the amount of fines during production. Wood fuel pellets have been produced at Karlstad University in a Pilot pellet production unit. Two cooling devices have been used, a custom built cooling tower and smaller cooling boxes where temperature, humidity, fan speed etc. are measured. Reference samples were cooled in a bucket over night and scattered in a large box on a perforated plate. All samples were cooled to ambient air temperature.The best results for the cooling tower on the durability and bulk density was the pellets scattered in a box and left overnight. Additionally, there were a minimal amount of fine fractions. Pellets cooled with the lowest fan effect also showed good results on durability. Pellets cooled in a bucket over night got very humid, and pellet cooled at maximum fan power iniciated cracks in the pellets due to a cool outside and hot inside of the pellets. The results for the smaller cooling boxes showed similair results but also showed that a lower bed hight of the pellets in the boxes gave increrased durability and hardness. A high fan speed gave poorer results on durability, mostly depending on that the air transport through the boxes became uneven. Further tests in an industrial environment measuring the electrycity should be done.
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| 29. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Mechanical Dewatering has Positive Effects on the Thermal Drying Efficiency and Wood Pellet Quality
- 2018
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Conference paper (other academic/artistic)abstract
- This work is done within the research group NewDeP (New Development for Pellet Technology), located at Karlstad University, Sweden. The NewDeP focus area is additive use, energy analyzes and bonding mechanisms. The research group manages test bed lab equipment including a single pellet press unit and a full pilot scale production unit, with the possibility to measure and analyze the pellet process from wet raw material to stored pellets.There is a need to increase the utilization of biomass and thus be part of the transformation towards a circular bio-economy, and also to do it with high energy-efficiency. When industries process biomasses, it is often done through multiple operations where drying is the most energy demanding step, since large quantities of thermal energy are used. The Drinor Continuous Dewatering Press (CDP) is a new Swedish compression press technology for dewatering of biomass. The CDP reduces the water content by 50% and reduces energy costs by 95%. Energy-efficient dewatering of biomasses increases the possibilities to use more by-products from the forest, and it could also be used in the creation of completely new process chains while refining raw materials. Including the CDP press in the pellet production chain creates new prerequisites for making pellets.In the literature are presented that the fibrous cell walls collapse under high pressure, resulting in the elimination of hemicellulose and lignin as well as affects further drying and internal diffusion of water. The fact that hemicellulosan's flexible polysaccharides strongly link to pelletability have been demonstrated in a recent study at Karlstad University and that lignin has positive bonding properties while high proportion of extractants is negative for pelletability. This is well described in the literature.This initial study had the aim to investigate how the CDP affects the drying and pelleting processes. The sawdust used was dewatered by the CDP from 55% down to 40 % (wb). The thermal drying tests was carried out in a pneumatic dryer with an inlet air temperature of 150°C from 40 % down to 10 % (wb). The pelltizing tests where done in both single pellet press unit and continous pilot scale production.Early results show that the change in material structures on the basis of the CDP have a positive effect on the drying efficiency (SMER) compared to non-pressed sawdust. Further, the CDP as a complement to thermal drying and its affection on the structure of sawdust and its porosity is favorable to the pellet density and hardness as well as the decrease in friction work during production (in a single pellet unit). The CDP could also reduce the energy needed for grinding since the results show that the lowest friction force in the press and highest pellet density and hardness was created from non-grinded material. The lower friction work could mean that the production rate could be increased producing good quality pellets. The results indicate that the pellet production chain can be redesigned using CDP but further research is needed.
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| 30. |
- Ståhl, Magnus, 1973-
(author)
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Minska energianvändningen i pelletspressen och öka pelletskvaliteten
- 2013
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Conference paper (other academic/artistic)abstract
- The wood fuel pellet industry demands energy efficient solutions for their production since these not only save energy but also money. One way of achieving this is to use additives. Choosing the right additive can save money but also increase the quality of the pellets, a win win situation. In this work, it is investigated how different kind of additives affect the energy use of the pelletizing equipment and also how it affects the durability of pellets. The best results were achieved using oxidized cornstarch as an additive during pellet production, it not only decreases the energy used the most but also produce the pellets with highest durability.
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| 31. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Research Experience From The Use Of Different Additives In Wood-Fuel Pellet Production
- 2017
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In: International Journal of Energy Production and Management. - : WIT Press. - 2056-3272 .- 2056-3280. ; 2:3, s. 288-293
-
Journal article (peer-reviewed)abstract
- 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.
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| 32. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Sustainable improvements in the wood fuel pellet chain
- 2014
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In: The Sustainable Energy and Environmental Protection.
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Conference paper (peer-reviewed)abstract
- A path towards sustainability should include growth with sustainable means such as the concept of Bioeconomy. The use of renewable resources for bioenergy should be performed to support sustainable development; however, biomass is made of limited resources and must be used efficiently and with a low environmental impact. The wood fuel pellet industry has the possibility to meet these criteria, but also has the potential for improvements. Earlier work on wood fuel pellet production has concluded that using oxidised cornstarch as an additive during pellet production decreases the energy used and also produces pellets with high durability. This work presents how additives such as cornstarch and molasses, affect the electricity use of the pellet press and also affect the emission of CO2 eq. from wood fuel pellet production. The results are presented for two different locations of the pellet plant, since the results will depend on how the electricity used is produced, e.g. using more or less renewable or fossil fuels in the electricity mix.
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| 33. |
- Ståhl, Magnus, 1973-, et al.
(author)
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Swedish Perspective on Wood Fuel Pellets for Household Heating : A Modified Standard for Pellets Could Reduce End-User Problems
- 2009
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In: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 33:5, s. 803-809
-
Journal article (peer-reviewed)abstract
- The use of wood fuel pellets has increased significantly over the past few years, and since 2006 the households use the major part of the pellets available in Sweden. During the same period, the oil heating has decreased. Many former oil users that were used to almost maintenance-free heating systems now use pellets. Despite significant improvements of pellet quality and storage and burner equipment, there are still some problems that the household pellets user encounters. In this work, common end-user problems are identified. The cause of each problem, as well as whether a modified Swedish standard for pellets could reduce some of the problems encountered, is analysed. The results show that the most serious problems originate from the crumbling of pellets. We conclude that many of the problems could be avoided by modifying the Swedish standard, e.g., the quality parameters could be set using intervals instead of threshold values.
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