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  • 351.
    Skantz, Christoffer
    Karlstad University, Faculty of Technology and Science.
    Äldreboendet på Zakrisdal: En studie om solvärme med säsongslagring2008Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A home for elderly is planed to be built at Zakrisdal, Karlstad, Sweden. The heat source for the building was at the time not determined. In order by the local government of Karlstad this report is meant to examine if the need of heat could be provided only by solar heat combined with a seasonal heat storage. The problem to solve is, if the need of heat from the home for elderly is provided from only solar heat, whitch dimensions of the solar collectors and the storage is needed?

  • 352.
    Skogsdal, Rickard
    Karlstad University, Faculty of Technology and Science.
    Evaluation of treatment techniques of the effluent air at biogas upgrading plants2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In nature, organic matter is degraded by microorganisms. During the degradation gases formedincludes methane, carbon dioxide, hydrogen sulfide, and small amounts of other gases such asVOCs. This has been utilized with help of anaerobic digesters, where environments have beencreated, in which these organisms thrive. In these chambers the gases are collected together intosomething called biogas.Biogas is a renewable energy source where the methane gas natural affinity for combustion inoxygen-containing environments is being used. By separating the methane from the other gases, theenergy value becomes closer to that of natural gas. The upgraded biogas can thus act as a substitutefor natural gas and be used as a fuel for vehicles, a need that has increased during the last years.This is preferred since natural gas is a fossil fuel.A technique used for upgrading biogas is water scrubbers. By using the gases different tendency todissolve into the water, carbon dioxide and hydrogen sulfide can be removed. During this process asmall amount methane and VOC becomes absorbed as well. The upgraded biogas obtains a methanecontent of approximately 98 % and can then be used as a fuel for vehicles. The removed gases are atthe same time released from the water to the effluent air leaving the upgrading plant. This has beendeemed inappropriate since the hydrogen sulfide is a corrosive and highly toxic gas. The methaneand VOCs that leaves with the effluent air provides negative effects to the greenhouse effect andglobal environment.This study has examined the issue of how to treat the gases that are emitted by the effluent air.Using measurements to find the percentage amounts of the different gases in the effluent air and inthe raw biogas, annual quantities of emissions could be calculated. From these, various treatmentmethods have been analyzed where the author finally concluded that a reduction of hydrogensulfide should be achieved with help of iron in a filter. Methane has instead been proposed to betreated with a compost filter.

  • 353.
    Sohlberg, Thomas
    Karlstad University, Faculty of Technology and Science.
    Biologisk reducering av nitrat och nitrit i vatten2007Independent thesis Basic level (professional degree), 15 points / 22,5 hpStudent thesis
    Abstract [en]

    During the summer 2007 was a scrubber tested at Gruvön papper mill in Grums. The scrubber reduced NOx with 90 % in flue gas. NOx was transferred from the flue gas to a scrubber liquid as nitrate and nitrite. The scrubber liquid needs to be purified from nitrate and nitrite.

     

    One possible solution is to clean the scrubber liquid in Gruvön biologic cleaning construction.

    Microorganisms in the biologic cleaning construction need to assimilate nitrogen. There are environments free from oxygen in the cleaning construction. Microorganisms can reduce nitrate in environments free from oxygen.   

     

    At the implementation was a labmodel built of the two first steps from Gruvön papper mill. Wastewater was collected from Gruvön papper mill. The wastewater was dosed with salts of nitrate and nitrite and pumped into the labmodel.

    The results showed that nitrate and nitrite can be reduced in content with help of the biological cleaning construction.

  • 354.
    Stawreberg, Lena
    Karlstad University, Faculty of Technology and Science.
    Energy Efficiency Improvements of Tumble Dryers: -Technical Development, Laundry Habits and Energy Labelling2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Tumble dryers are becoming more and more common in ordinary households as a complement to the washing machine. Tumble dryers offer a fast drying cycle independent on weather conditions and require small space. They do, however, considering the large number of units use a large amount of electricity. The main objective in this thesis is to identify possibilities in order to reach a reduced electricity use for domestic tumble-drying of clothes. This involves an investigation of the condensing tumble dryer in order to point out possible energy efficiency improvements. The purpose of the energy label, which indicates the energy efficiency of the tumble dryer, is also studied, whether it matches the actual laundry habits. Finally, suggestions for technical development of the tumble dryer are made in line with today’s consumer behaviour.

    The performance of the condensing tumble dryer has been studied using a design of experiments to create a statistical model in Paper I. This model was used to find the best settings for the power supply to the heater, the internal airflow and the external airflow in order to reach a high specific moisture extraction rate (SMER) and a low leakage ratio. A low external airflow and high power supply to the heater gives the highest SMER. To reach the lowest values for the leakage ratio, a low internal airflow should be applied together with a high external airflow. The use of a statistical model gave valuable information of the performance of the existing tumble dryer. For further improving the energy efficiency of the dryer, the amount of leakage and its location was investigated in Paper IV. By studying energy and mass balances from experiments, pressure measurements and modelling, the effects of leakage on the process were evaluated. As the location of the leakage is so important for the energy efficiency, the worst-case scenario where leakage is located between the heater and the drum is used as a start point in the study. It was determined that there is a large leakage of air between the heater and the drum leading to a significant loss in energy recovery.

    The drying loads used by consumers are getting smaller, often less than 3 kg dry load, while the maximum capacity of the dryers are increasing, up to 7 or 8 kg. In Paper II, tests were made with different loads in order to investigate if the energy label serves its purpose as today’s standard is set at the dryers’ maximum capacity. The results from this study show that the energy efficiency when drying a small load is significantly lower than for a large load. In order to encourage a production of tumble dryers with higher energy efficiency for small loads, where the dryer is most frequently used, the standards for the energy label should be revised. Today, manufacturers do not gain any benefits by improving the performance for partial loads.

    A mathematical model over a venting tumble dryer was established in Paper III with the aim of testing different control strategies in order to improve the energy efficiency of the tumble dryer for partial loads. The ideas behind the different strategies were to minimize the heat losses during the drying process and to increase the residence time for the air in the drum and thereby increase the moisture content of the air leaving the drum. Using such a control strategy it is possible to reach an improvement of SMER by approximately 4% when drying small loads. In order to reach larger improvements, however, a more extensive product development will be necessary.

    Finally, the results in this thesis points at the necessity of including not only the technical development of the tumble dryer, but also the policy tools involved and the consumers’ habits in order to reach a reduced electricity use for drying clothes in households. 

  • 355.
    Stawreberg, Lena
    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.
    Energy Losses by Air Leakage in Condensing Tumble Dryers2012In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 37, no May, p. 373-379Article in journal (Refereed)
    Abstract [en]

    Tumble dryers, used for the drying of textiles, consume a considerable amount of electricity due to the large number of dryers in use. A large amount of this electricity is produced from coal, making it important to reduce the electricity use and, hence, the carbon dioxide emissions. Earlier studies made on the condensing tumble dryer have pointed out that leakage is one of the parameters affecting the electricity use for the drying process. With a view to reducing the energy use, leakage was estimated through measurements and modelling. Energy balances were used in order to verify the leakage. The energy balance showed good agreement with the results from the model and confirms that the leakage out from the dryer arises mainly between the heater and the drum where the air is hot and has low relative humidity. Large leakage at this location is detrimental for the energy efficiency of the dryer, meaning that the leakage must be reduced in order to obtain a reduced energy use. Results from the model also point out that even small changes in the size of gaps, or changes to the pressure in the internal system, result in a significant change in leakage from the dryer

  • 356.
    Stawreberg, Lena
    et al.
    Karlstad University, Faculty of Technology and Science.
    Nilsson, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Modelling of Specific Moisture Extraction Rate and Leakage Ratio in a Condensing Tumble Dryer2010In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 30, p. 2173-2179Article in journal (Refereed)
  • 357.
    Stawreberg, Lena
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Nilsson, Lars
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Potential Energy Savings Made by Using a Specific Control Strategy when Tumble Drying Small Loads2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 102, p. 484-491Article in journal (Refereed)
    Abstract [en]

    Tumble dryers manufactured today are optimised for their maximum capacity, i.e., 6–8 kg of dry load. An average washing load in ordinary households lands at between 2 and 3.5 kg dry load, which implies that the drying load is even smaller. The energy efficiency decreases with reduced drying load. The aim of this study is to establish a mathematical model for studying alternative control strategies for the venting tumble dryer in order to increase the energy efficiency of drying small loads. Two series of test runs were performed: the first series with three different drying loads was used as reference tests for validation of the mathematical model, and the second series was performed with airflow reduction. The model shows good agreement with the test runs. Two control strategies were tested using the model on the smallest drying load. By lowering the heat supply to the heater and by reducing the airflow, the energy efficiency increases by 6% in a small load drying cycle. It was not possible, however, for the investigated dryer, to reach the same energy efficiency for small loads as for the maximum drying load by using a control strategy.

  • 358.
    Stawreberg, Lena
    et al.
    Karlstad University, Faculty of Technology and Science.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science.
    Does the energy labelling system for domestic tumble dryers serve its purpose?2011In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 19, p. 1300-1305Article in journal (Refereed)
  • 359.
    Strömner, Fredrik
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences.
    Jämförande LCA av engångssängkläder och tvättbara sängkläder i sjukvården2014Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In healthcare – as in any other place where people sleep – beddings are used for hygiene reasons. Problems with spreading of bacteria diseases such as multi resistant bacteria (MRSA) and various other diseases have pushed companies like Cellcomb i Karlstad AB to develop disposable beddings in order to prevent this. These disposable beddings are protected with a biofilm which serves as a barrier, preventing liquids to pass through. The problem is that there is not much information about how these beddings perform from an environmental perspective. At present, hospitals are using traditional beddings for their patients and are then transported to laundries for washing. This is an energy intensive process and as an alternative, disposable beddings could be used. A simplified LCA was used to find out if beddings made out of cotton and polyester or disposable beddings made out of polypropylene or a viscose material called Tencel was the most favourable from an environmental perspective. To achieve this, various study visits were performed along with a literature study and data collection from companies. The results showed that for a basic case performed with Centralsjukhuset i Karlstad the washable beddings used less energy than Tencel and negligibly less energy than polypropylene. Several case studies were performed in order to examine how different data could alter the results. The case studies showed that which of the alternatives became the most favourable varied depending on the case, especially regarding which kind of energy was being used in the laundry. The disposable beddings made out of Tencel proved to be the best alternative regarding the use of renewable energy, followed by the washable beddings and last polypropylene. From a perspective of eco toxicity and water use both of the disposable beddings turned out more favourable. Two conclusions could be drawn from this study: the alternatives are equally favourable regarding energy use, renewable energy use and the case studies that were performed, but the disposable beddings are more preferable concerning eco toxicity and water use. The second conclusion is that the results depend on which case is studied. An expanded study could be performed using more environmental parameters.

  • 360.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Drying Parameter Variation and Wood Fuel Pellets Quality'Pilot Study with a new Pelleting Equipment Set up2006Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    The new pelleting equipment set up, in combination with an integrated automatic control system and the existing pilot-scale dryer, in the laboratory at the Department of Environmental and Energy Systems at Karlstad University in Sweden, make it possible to run a variety of tests. With the integrated control system the possibility to make adjustments throughout the chain with the aim to decrease the energy demand and improve the pellet quality with focus on the strength of the pellet, moisture content etc are possible. Thus, we have an unique possibility to control the whole production chain, from wet sawdust to pellets. Publications that combine the drying of the raw material with the quality properties of wood fuel pellets are rare. Therefore, research that aims at investigating dryer performance and its effects on chosen pellet quality parameters is to be performed. From now on our department have the tools and possibility to contribute to that field of research

  • 361.
    Ståhl, Magnus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Energy reduction in wood fuel pellet production: Verringerung des Energieverbrauchs bei der Produktion von Holzpellets2012In: 12th Pellets Industry Forum Proceedings: Internationaler Fachkongress zum Pelletsmarkt, Pforzheim, Germany: Solar Promotion , 2012, p. 85-90Conference paper (Refereed)
    Abstract [en]

    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.

  • 362.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Improving Wood Fuel Pellets for Household Use: Perspectives on Quality, Efficiency and Environment2008Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    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).

  • 363.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Theoretical Effects of Recirculation of Drying Gases in a Co-current Rotary Dryer2005Conference paper (Other (popular science, discussion, etc.))
    Abstract [en]

    The most energy demanding process in manufacturing of biofuels is drying. When drying is needed it is together with the raw material the main cost factors for pellet production. The most common drying technique used in the Swedish pellet industry for drying sawdust is a direct-fired rotary dryer. Recirculation of drying gases can contribute to energy efficient operation of dryers.



    Improvements due to recirculation of drying gases are elucidated in four system configuration scenarios using a mathematical model. The results indicate that for different scenarios the dew point of the gases leaving the dryer may be unaffected or increase significantly when the recirculation ratio increases. The latter is important for the district heating demand as a higher dew point implies that the energy recovered in the condenser becomes more useful especially at higher return flow temperatures. Optimisation of the drying process regarding dryer capacity and energy recovery is suggested

  • 364.
    Ståhl, Magnus
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Wood Fuel Pellets: Sawdust Drying in the Energy System2005Licentiate thesis, monograph (Other academic)
    Abstract [en]

    In 2004, the amount of wood fuel pellets used in Sweden was 1 256 000 tons, it was mostly used in large scale burning for district heating. Over the last 10 years, a significant increase in pellet production has occurred and today the preferred raw materials for pellet production, i.e., dry sawdust and wood shavings, are insufficient. New raw materials could be used. However, the quality demanding residential customer that uses a pellet burner or a pellet stove with limited emission control prefers stem wood pellets. One solution could be to increase the drying of wet raw materials, such as wood chips.

    The most common technique in Sweden for the drying of sawdust is to use a directly fired co-current rotary dryer, although steam drying does occur when co-generation is possible. In the production chain for pellets, the drying process is the most energy consuming process and, together with the raw material, it is the main cost factor for the manufacturer. Thus, it is important to run the drying process as energy efficiently and environmentally friendly as possible. This thesis, therefore, discusses the effects of the drying of sawdust, which is the primary raw material for wood pellets.

    In the work described in Paper I, the moisture content and emission of terpenes during the drying and pelleting steps of the pellets production are examined. Furthermore, the effects on pellet quality are examined. In the work described in Paper II, the recirculation of drying gases in a rotary dryer is examined from the point of view of energy savings and dryer capacity.

    The drying process also affects the pellet quality. Drying of sawdust can be used to control quality properties, such as moisture content and emissions of Volatile Organic Compounds (VOC). Almost all of the monoterpenes are emitted during the drying and pelleting steps causing environmental and health related problems (see Paper I).

    Energy savings can be made using recirculation of the drying gases. Increased recirculation could mean higher dew points in the emitted drying gases, which increases the chances to use the energy from the emitted drying gases for secondary processes connected to the dryer system, such as district heating. However, there is a conflict between recirculation ratio/recovered energy and drying performance (see Paper II)

  • 365.
    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.
    Energy Efficient Pilot-Scale Production of Wood Fuel Pellets made from a Raw Material Mix Including Sawdust and Rapeseed Cake2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no 12, p. 4849-4854Article in journal (Refereed)
    Abstract [en]

    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.

  • 366.
    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.
    Validation of a Developed Mathematical Model by Studying the Effects of Recirculation of Drying Gases2008In: Drying TechnologyArticle in journal (Refereed)
  • 367.
    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.
    Validation of a Developed Mathematical Model Studying the Effects of Recirculation of Drying Gases2006Conference paper (Refereed)
    Abstract [en]

    Drying is a costly and energy consuming process. Consequently, it is of great practical importance to improve its energy efficiency. Our objective, therefore, is to develop and validate a theoretical drying model by studying the recirculation of drying gases. The results show that the amount of recovered energy over the condenser and the dryer efficiency increase with increased recirculation, implying an energy efficient operation. The validation shows that the model correlates well with industrial data. Accordingly, it should be possible to use the model industrially to predict capacity changes and energy recovered when changes in drying gas recirculation are made

  • 368.
    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.
    Validation of a Mathematical Model by Studying the Effects of Recirculation of Drying Gases2008In: Drying Technology, ISSN 0737-3937, E-ISSN 1532-2300, Vol. 26, no 6, p. 786-792Article in journal (Refereed)
  • 369.
    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

  • 370.
    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%

  • 371.
    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).
    Williams, Helén
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Energy efficiency, greenhouse gas emissions and durability when using additives in the wood fuel pellet chain2016In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 152, p. 350-355Article in journal (Refereed)
    Abstract [en]

    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.

  • 372.
    Ståhl, Magnus
    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.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Industrial processes for biomass drying and their effects on the quality properties of wood pellets2002Conference paper (Refereed)
  • 373.
    Ståhl, Magnus
    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.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Industrial processes for biomass drying and their effects on the quality properties of wood pellets2004In: Biomass and Bioenergy 27:621-628, 2004, Vol. Vol.27, p. 621-628Article in journal (Refereed)
    Abstract [en]

    This paper contributes to the discussion of how different kinds of industrial scale dryers for biomass influence the quality properties of wood pellets. It also discusses how the drying technique can affect the environment. The most common biomass drying processes in use, i.e., convection dryers are discussed. The discussion of drying techniques is based on advantages and disadvantages with a focus on the drying medium,temperature and residence time. The choice of drying technique is particularly important if the end-users choice of pellets is made due to the specific requirements for the heating system used. Some specific parameters were tested in order to investigate how the choice of drying technique affects the pellet quality. The parameters tested were moisture content and the emissions of volatile hydrocarbons. Pellets available on the market were chosen for the tests. The amount of volatile hydrocarbons left in sawdust after drying vary with drying technique, as emissions of terpenes are larger in dryers with long residence times. Low emissions of volatile hydrocarbons would improve the energy content of the sawdust, and by decreasing air pollution improve the work environment and the environment in the surroundings of the dryers

  • 374.
    Ståhl, Magnus
    et al.
    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.
    Swedish Perspective on Wood Fuel Pellets for Household Heating: A Modified Standard for Pellets Could Reduce End-User Problems2009In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 33, no 5, p. 803-809Article in journal (Refereed)
    Abstract [en]

    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.

  • 375.
    Ståhl, Magnus
    et al.
    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.
    Wood Fuel Pellet Technology Research: Quality and Environmental AspectsManuscript (Other academic)
  • 376. Svensson, Ch
    et al.
    Olin, Malin
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Thernquist, P
    Ekman, M
    Litteratursammanställning om grundvatten i urban miljö på Internet1996Other (Other (popular science, discussion, etc.))
  • 377.
    Thyberg, Viktor
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Numerical Energy Modeling to Increase Fuel Efficiency of An Activated Carbon Production2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
  • 378.
    Tolf, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Kallöslig stärkelse som tillsats i träbränslepellets: Effekter på pelletkvalitet och energianvändning2019Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
  • 379.
    Toresson Nygårds, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Solceller på kommunala typfastigheter: En  detaljstudie av kommunala typfastigheter i Forshaga kommun2019Independent thesis Basic level (university diploma), 180 HE creditsStudent thesis
    Abstract [en]

    The expansion of photovoltaic plants has increased significantly within the EU and in Sweden, where a contributing cause has been a higher environmental thinking and lower prices for solar cell installations. Interest in installing solar cells has increased in society as a whole and an increasing number of municipalities are interested in solar cells. One of these municipalities is Forshaga municipality, which strives to be climate neutral until 2030.

    This study examined whether a number of selected municipal properties in the Forshaga municipality were suitable for installing solar cells based on the degree of self-use and the degree of self-sufficiency and the electricity cost of produced electricity (LCOE - Levelized cost of energy). The study also examined whether these selected properties would be suitable for solar cells if certain conditions were changed to simulate that they were located in another location with different conditions. Of the properties included in the study, there was a care home, two schools, Forshaga municipal house, a wastewater treatment plant and a waterplant.

    Of the examined municipal properties, a school, the nursing home and the municipal house were considered most suitable for solar cells based on the above criteria. The property that was considered most suitable was the Grossbolskolan which was the smaller of the two schools. Grossbolskolan had a self-utilization rate and a self-sufficiency rate of 87 and 15 percent respectively and the lowest cost for the produced electricity by about 0.88 SEK/kWh. The municipal house and the care home had a slightly higher production cost for the produced electricity.

    Some conclusions could be drawn from the part of the study that examined whether the properties were suitable for mounting solar cells if they had been placed in another location with other conditions. One conclusion was that the properties should have a similar electricity consumption as the investigated properties in this study, with a higher electricity consumption daytime when the solar cells produce the most to obtain a high self-use. The degree of selfuse was highest for the plants that were located in the east / west direction, which indicates that the electricity consumption in these type properties was more suitable for solar cell installations whose production is more widespread throughout the day. In order for the repayment period not to exceed the assumed life expectancy of the solar cell plant of 25 years, the self-use rate should not be less than 50 to 60 percent. Finally, the study also found that the properties recommended as suitable had between 1 - 3.5 m2 solar cells / MWh annual electricity use in the property, which can be used as a guideline value to see if the property is suitable for solar cells. If this value were lower, the self-sufficiency rate was low, if it was greater, the self-utilization rate was low. 

  • 380.
    Ulvmyr, Amanda
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Potential risks and prospects of protections of a hydrokinetic turbine implemented in the Amazon River, Colombia: A theoretical and practical study2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Electricity has been proved to be a crucial factor to achieve an economic and social development in emergent countries and is seen as a necessity to deplete the world’s poverty. As energy resources are getting scarce, a higher implementation of renewable electricity generation, such as hydropower, is a necessity.

    Hydrokinetic turbines, which use slow flowing water as a source of energy, are to be installed in the Amazonas River in Colombia.

    The Amazon River has high amount of sediment and flowing objects due to the large quantity of vegetation in the area. This leaves the turbine exposed to a higher degree of erosion on the blades and a higher risk of getting clogged. The efficiency will decrease and the turbine will have an impending risk of getting damaged. By adapting the hydrokinetic turbine for the conditions prevailing in the Amazon basin, the efficiency can be improved and a longer lifetime for the turbine is given.

    A field study was conducted to attain the velocity and amount of sediment in the Amazon River through measurements. The collected data was analyzed and used as input values during simulations of a turbine model by the Computational Fluid Dynamics program COMSOL.

    Areas on the turbine exposed to the water with a high velocity, and containing a high concentration of sediment, were examined and proposals for protection were given. Also the necessity and consequences of installing a protective grate in front of the turbine were investigated.

    The turbine will be exposed to almost a factor of 12 000 higher erosive wear in the Amazon River than in Swedish water as of the higher amount of sediment. The investigation states that areas on the tip of the blade’s rear side and the area close to the rotating center are most exposed to erosion and will be in need of protection in form of a harder surface. A grate will be necessary to provide a longer lifetime for the turbine, but will result in a decreased power output from the turbine by up to 46 %. 

  • 381.
    Vernersson, Annelie
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Utredning och effektivisering av Kils Energis fjärrvärmenät: Lokalisering av undercentral med lägst differenstryck2014Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Kil Energy is a small district heating network with 620 subscribers, mostly villas. With a low line density, it is important to have as low a cost as possible, and thus an effective system where as much as possible of the heat is used. In order to eventually be able to decide on improvements in the system needed an investigation of the system for deeper understanding of how the Internet works today. To get to know the system investigated in this thesis was the subscriber who had the lowest differential pressure, was the largest pressure drops up to this subscriber occurred, how this differential pressure could be improved and whether it is economically feasible. And the supply temperature as today has the lowest operating cost, what would happen to the pressure of the flow line temperature should be maintained at -20˚ Celsius and which flow is the maximum possible before maximum pressure of 16 bar is reached. Using simulation program NetSim found a subscriber named UC 5692 with a minimum differential pressure of 39 kilopascals at -20˚ Celsius. Maximum pressure drop could be determined at line P54, P704 and P1210 with over 200 Pascal pressure drop per meter. Change in control against UC 5692 obtained a minimum differential pressure of 99.5 kilopascals UC 5692nd The highest flow was measured to be about 120 kg / s and was developed in NetSim by increasing the power output from the customers. With the help of Excel a chart was made with the lowest operating cost between 77-88˚ Celsius. This was developed with the help of the 2012 operating data from Kil Energy. To install an additional pump in the network in order to ensure the lowest differential pressure to acceptable levels yielded a higher operating cost, which would not be economically viable when the investment would never have any payback in the form of lower operating cost. To change the governance against UC 5692 is a simple and inexpensive solution to improve the operating pressure without putting down any major work in action. The cheapest supply water temperature is 85˚ Celsius. When the flow temperature was held at 85˚Celsius at -20˚Celsius outdoor temperature was pressure drop across 200 Pascals per meter in large areas of the network compared to regular operation. A possible combination could be to change the steering while trying to keep as close to the cheapest, the supply temperature as possible, to reduce operating costs. Given the global warming that makes the winters are milder then it should be possible to keep a flow temperature of 85˚ most of the year. However, should be investigated in NetSim, when the flow temperature should be increased with decreasing outside temperatures, to avoid the high flows that cause high pressure drops. This is to optimize the operation and know when it is time to raise the supply temperature to avoid excessive pressure drop when the power demand increases.

  • 382.
    Vestblad, Jennifer
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Cirkulerande återanvändning av sportartiklar: Resursflöden för framställning och avfallshantering av sportartiklar2016Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    A clear pattern shows that the amount of waste increases with the increasing consumption. The consumption leads to more manufactured products which later on must be disposed as waste. Except trying to prevent the amount of waste, reusing products is a great option for waste managements.

    Fritidsbanken started 2013 in Deje Värmland and works like an organized lending system with sporting goods. The operation is largely based on advocating reuse. Fritidsbanken works like a library with sporting goods where anyone can borrow equipment for free. By giving the chance to practice activities and sports, Fritidsbanken creates conditions for spontaneous sporting. The study is based on the business premises in Deje, where three different sporting goods were examined: downhill skis, cross country skis and ice skates.

    The study examined the resource flows, production- and waste processes with the business as a base. The submitted articles were compared with the corresponding number of articles submitted, reused and discarded. Also the waste disposal of that time was reviewed and alternative improvements were presented. 

    The study was based on a separate survey of how waste management of products were carried out at the study’s start. The survey emanated from the central parts of Värmland in Sweden. Additional a sensivity analysis was performed and based on the materials found in the articles, presenting an increased mass of 5, 10 or 15 %.  The method for the study consisted largely of contacts with producers, recyclers, authorities and recycling centres. Information about the articles and its content were collected from CES – Edu Pack and Fritidbanken in Deje.

    The result of the study shows that the reuse gives a positive impact on the production of materials, waste management and resource flows. A total amount of 1480 kg material, 9.3 tonnes of carbon dioxide emissions and 122 GJ amount of energy, were avoided in material production. The proposal regarding the waste disposal of articles can lead to 34 GJ energy derived from combustion and a recycled amount of 263 kg steel.

    The study was based on three different sporting goods which were collected from Fritidsbanken in Deje during autumn 2015. Similar products may contain other types of materials and should be examined accordingly. The sensitivity analysis shows that steel, epoxy-fiberglass and nylon were the materials that required the most energy in material production. It was also the material that produced the most carbon dioxide for the same process. The result from the sensitivity analysis also shows that epoxy-fiberglass may contain dangerous substances. Because of this the amount of epoxy-fiberglass should not increase or be used with a higher consumption. With that said, improved material selection can be considered from the article’s life cycle perspective.

  • 383.
    Vesterholm, Patrik
    Karlstad University, Faculty of Technology and Science.
    Applicering av extremalsökande reglering på ett tvåkroppsvågkraftverk med hjälp av Simulink2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Vågkraft är en stor outnyttjad energiresurs som har flera fördelar gentemot andra hållbara energikällor, främst i intensitetsfördelningen över året. Vågkraftkonvertering är dock problematiskt att reglera och en lösning skulle kunna vara extremalsökande reglering. En extremalsökande regulator söker efter gradienter i en referenssignal genom att manipulera en styrsignal. När den finner en gradient låter man styrsignalen ändras i gradientens riktning tills gradienten är lika stor oavsett i vilken riktning man ändrar styrsignalen. Sedan man år 2000 bevisade att extremalsökande reglering konvergerar mot ett extremvärde har intresset för denna typ av reglering ökat drastiskt. Fördelen är framför allt att man kan reglera ett system med väldigt liten kunskap om systemet man reglerar. I denna artikel appliceras extremalsökande reglering på en modell av ett tvåkroppsvågkraftverk skapad i Simulink av Jan Forsberg. Den extremalsökande regulatorn maximerar vågkraftverkets momentant absorberade effekt genom att manipulera dess generators vridmoment. Det visar sig att systemets dynamik är för långsamt för att reglering med en extremalsökande regulator ska öka dess upptagna effekt jämfört med att inte reglera systemet alls. 

  • 384.
    Viklöf, Evelina
    Karlstad University.
    Förstudue till en Miljökonsekvensbeskrivning angående rivning av vattenkraftesdammar: Samt simulering av av vattenflöden2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    On the basis of a legislative amendment that came into force in January 2019, which states that all dams will have to achieve modern environmental conditions, all hydropower dams in  Sweden will need to be licensed. Arvika Kraft has two regulating dams Kivilamp and Rolamp  which they do not believe will achieve the modern environmental conditions. Arvika Kraft  therefore wants to have a feasibility study for an environmental impact assessment carried out  in order to be able to study possible measures for the dams. They wanted a potential  demolition of the two regulatory ponds to be studied in this preliminary study.

    In an environmental impact statement, several alternatives are to be studied, and in this  feasibility study, the zero alternative is to maintain the regulating dams as they are today, the  main alternative being to demolish the two damsand the third alternative that was chosen to be  studied is the introduction of turbines in the dams along with the construction of fish roads  passing them. 

    In the report, a literature study is carried out to deepen the knowledge in the area, a modeling of the three alternatives to be able to study how the energy production of the power dam  downstream as Kivilamp and Rolamp acts as a regulator are affected, and finally the actual  collection of information for the preliminary study of the environmental impact assessment. 

    The result of the study shows that the zero alternatives contribute to regulation that increases energy production of the power dam downstream but that the two ponds Kivilamp and  Rolamp are migratory obstacles to the aquatic animals. The problem with the zero alternative  also remains that there is a great risk that the dams do not meet the modern environmental  goals at present. 

    The result of the main alternative shows that, according to the models, energy production would be lowered in the event of a demolition of the two regulating dams. The water flow, on  the other hand, would be more natural and the two migratory obstacles would disappear for  the aquatic animals. However, the flow would continue to be dammed downstream, which  would mean that only a small section of the total flow path would be free from migratory  obstacles. 

    For the third option studied, the result was an increased energy production but not as high as expected because the two regulating dams had a relatively low drop height compared to the  power dam downstream and that the flow was somewhat lower for Kivilamp and Rolamp in  comparison. By way of the constructed fishing roads, on the other hand, free movement would be facilitated and this would be a positive change for the aquatic animals. 

    The conclusion was that the best alternative where energy production was weighed together with an improved environment for the aquatic animals was the third option. However, this can  be costly and difficult to implement in practice and in such cases the best thing would be to  demolish the regulating dams.

  • 385. Wenzhöfer, Frank
    et al.
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Glud, Ronnie N.
    Nielsen, Helle K.
    Gundersen, Jens K.
    In situ microsensor studies of a shallow water hydrothermal vent at Milos, Greece2000In: Marine Chemistry. 69: 43-54Article in journal (Refereed)
  • 386. Wenzhöfer, Frank
    et al.
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kohls, Oliver
    Deep penetrating benthic oxygen profiles measured in situ by oxygen optodes2001In: Deep-Sea Research I 48: 1741-1755(In press, Deep Sea Research)Article in journal (Refereed)
  • 387.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    A theoretical explanation of the Piper-Steenbjerg effect1994In: Plant, Cell and Environment 17: 1053-1060, 1994Article in journal (Refereed)
  • 388.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Allocation of mass in trees under nitrogen and magnesium limitation1995In: Tree Physiology 15, 339-344, 1995Article in journal (Refereed)
  • 389.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Att undervisa i och examinera abstrakt tänkande2006In: Proceedings 2005: utvecklingskonferensen 16-18 november i Karlstad / [ed] Ingrid Järnefelt, Lund: Lunds universitet , 2006Conference paper (Other (popular science, discussion, etc.))
  • 390.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Beräkningar av näringsbalanser och kväveförluster vid helträdsutnyttjande1992In: Vattenfall Bioenergi Research, U(B) 1992/16Article in journal (Refereed)
  • 391.
    Wikström, Fredrik
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    The Potential of Energy Utilization from Logging Residues With Regard to the Availability of Ashes2007In: Biomass and Bioenergy 2007; 31: 40-45Article in journal (Refereed)
  • 392.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Karli, Verghese
    RMIT University, Melbourne, Australia.
    Rafael, Auras
    Michigan State University, East Lansing, MI, USA.
    Olsson, Annika
    Lund University, Lund.
    Williams, Helén
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Wever, Renee
    Linköping University.
    Grönman, Kaisa
    Lappeenranta University of Technology, Lappeenranta, Finland.
    Kvalvåg Pettersen, Marit
    Nofima AS,Ås, Norway.
    Møller, Hanne
    Ostfold Research, Kråkeröy, Norway.
    Risto, Soukka
    Lappeenranta University of Technology, Lappeenranta, Finland.
    Packaging Strategies That Save Food: A Research Agenda for 20302019In: Journal of Industrial Ecology, ISSN 1088-1980, E-ISSN 1530-9290, Vol. 23, no 3, p. 532-540Article in journal (Refereed)
    Abstract [en]

    Summary Thoroughly considering and optimizing packaging systems can avoid food loss and waste. We suggest a number of issues that must be explored and review the associated challenges. Five main issues were recognized through the extensive experience of the authors and engagement of multiple stakeholders. The issues promoted are classified as follows: (1) identify and obtain specific data of packaging functions that influence food waste; (2) understand the total environmental burden of product/package by considering the trade‐off between product protection and preservation and environmental footprint; (3) develop understanding of how these functions should be treated in environmental footprint evaluations; (4) improve packaging design processes to also consider reducing food waste; and (5) analyze stakeholder incentives to reduce food loss and waste. Packaging measures that save food will be important to fulfill the United Nations Sustainable Development goal to halve per capita global food waste at the retail and consumer levels and to reduce food losses along production and supply chains.

  • 393.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Karlsson, Mikael
    Karlstad University, Faculty of Social and Life Sciences, Department of Health and Environmental Sciences.
    Hållbar utveckling i skogslandskapet ' med energi i fokus2004Chapter in book (Other academic)
  • 394.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Karlsson, Mikael
    Karlstad University, Faculty of Social and Life Sciences, Department of Health and Environmental Sciences.
    Hållbar utveckling i Värmland - Strategier för lokal och regional hållbar utveckling av energisystem i ett femtioårsperspektiv2002Report (Refereed)
  • 395.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Olsson, A
    Nilsson, F
    Hellström, D
    Bra förpackning skyddar och säljer i hållbart system2011In: Miljöforskning, ISSN 2000-8627, no januariArticle in journal (Other (popular science, discussion, etc.))
  • 396.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Williams, Helén
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ger mindre förpackningsmaterial mindre avfall?2010In: Återvinnare för industrin 2010 / [ed] Kjell-Arne Larsson, Stockholm: Rekord Media och Produktion , 2010Chapter in book (Other academic)
  • 397.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Williams, Helén
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Packaging and Food Waste Behavior2017In: Reference Module in Food Sciences, Elsevier, 2017, p. 1-4Chapter in book (Refereed)
    Abstract [en]

    Packaging saves food by protecting the content from physical and chemical degradation during the distribution and storage processes. However, packaging can do much more than that. This article explores how the design of a package may help, or indeed hinder, the consumer to avoid wasting food. A number of packaging attributes influence consumer behavior. The influence is different depending on the product‘s characteristics and the needs of the consumer. For many products, it might be better to add packaging material, for example, by creating smaller sizes of the product to reduce food waste and the overall environmental impact.

  • 398.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Williams, Helén
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Potential environmental gains from reducing food losses through development of new packaging – a life cycle model.2010In: Packaging technology & science, ISSN 0894-3214, E-ISSN 1099-1522, Vol. 23, no 7, p. 403-411Article in journal (Refereed)
    Abstract [en]

    The environmental concern and development issues regarding packaging has for 20 years to a high extent been on packaging when it has become waste. To reduce the environmental impact from the whole food packaging system it is also important to develop the packaging’s ability to reduce food waste. In some cases it may be necessary to increase the environmental impact of packaging in order to reduce food waste. In this paper, the environmental impact of packaging and food losses and the balance between the two has been examined for five different food items. The results show that packaging’s that reduce food waste can be an important tool to reduce the total environmental impact, even if there is an increase in impact from the packaging itself. This is especially true for food items where the environ- mental impact of the food is high relative the packaging, for example cheese, and for food items with high losses, for example bread. It is important to analyse the risk of increasing food losses when pack- aging design changes, for example, when the aim is less packaging material, which is the main intention of the packaging and packaging waste directive of the European Union.

  • 399.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Williams, Helén
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Govindarajan, Venkatesh
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    The influence of packaging attributes on recycling and food waste behaviour – An environmental comparison of two packaging alternatives2016In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 137, p. 895-902Article in journal (Refereed)
    Abstract [en]

    This paper analyses how user behaviour influences the environmental comparison of two different packages for minced meat - a lightweight tube and a tray. The direct and indirect environmental effects are evaluated using simplified LCA. A number of packaging attributes with regard to food waste and recycling behaviour are analysed for the packages, and then used for the scenario calculations. The results show that the tube is the superior environmental alternative when only the direct effects are considered. When indirect effects and user behaviour are included in the comparison, the tray is the better alternative due to higher recycling rates and, most importantly, less food waste during the process of emptying. However, the environmental impacts due to the food waste in the tube may be compensated for, if the longer shelf-life of the tube results in lower wastage in the households. It is concluded that indirect environmental effects and user behaviour should be included in environmental assessments of packaging to obtain meaningful results.

  • 400.
    Wikström, Fredrik
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Williams, Helén
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Trischler, Jakob
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Service Research Center (from 2013).
    Rowe, Zane
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    The importance of packaging functions for food waste of different products in households2019In: Sustainability, ISSN 2071-1050, E-ISSN 2071-1050, Vol. 11, no 9, p. 1-16, article id 2641Article in journal (Refereed)
    Abstract [en]

    The United Nations sustainability goal SDG 12.3 is to reduce the amount of food that is wasted by half, due to environmental and social reasons. This paper aims to analyse the most important packaging functions that affect food waste in households for different products, as the reason for wastage can be expected to differ between different products. The reasons for food wastage of different categories and products have been compiled through literature studies, and possible improvements of packaging functions to reduce food waste have been identified. In addition, an expert workshop judged the most important packaging functions to reduce food waste for a number of products. They also discussed the obstacles and possibilities to realise the packaging improvements. This study confirms that how packaging functions influence food waste on the product level is a highly unexplored question. Most likely, there is high potential to reduce food waste through better adaptions of packaging functions to user needs and habits. Both the literature study and the expert workshop show that less food per pack and better information regarding food safety and storage have high potential to reduce food waste, but also that product specific considerations are necessary.

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