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  • 1.
    A., Trubetskaya
    et al.
    National University of Ireland Galway.
    G. R., Surup
    University of Agder.
    Forsberg, Fredrik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics.
    T., Attard
    University of York.
    A., Hunt
    Khon Kaen University.
    V., Budarin
    University of York.
    V., Abdelsayed
    National Energy Technology Laboratory.
    D., Shekhawat
    National Energy Technology Laboratory.
    The Effect of Wood Composition and Supercritical CO2 Extraction on the Charcoal Production2019In: 2019 AIChE Annual Meeting proceedings, American Institute of Chemical Engineers, 2019, article id 552cConference paper (Other academic)
    Abstract [en]

    This work demonstrated that the coupling of supercritical carbon dioxide extraction with slow pyrolysis is effective to remove over half of extractives from low quality wood and to generate biochar from remaining solid wood fractions. The high yields of extractives from supercritical carbon dioxide extraction illustrates the potential utilizing of low quality wood as an alternative feedstock for the sustainable production of value-added chemicals. Results showed that supercritical carbon dioxide extraction has neither a strong impact on the physical properties of original wood nor on the yield of solid biochar. These results are promising as they show that the biochar obtained for this renewable feedstock could be used as an alternative to fossil-based coke in applications including ferroalloy industries. Moreover, the heat treatment temperature and supercritical carbon dioxide extraction had a significant impact on the tar yields, leading to the increase in naphthalene, polycyclic aromatic hydrocarbons, aromatic and phenolic fractions with the greater temperature. The differences in gasification reactivity and dielectric properties of solid biochars, composition and yields of liquid products of non-treated pinewood and extracted wood fraction emphasize the impact of supercritical carbon dioxide extraction on the pyrolysis process. 

  • 2.
    Abrahamsson, Louise
    Linköping University, Department of Thematic Studies, Tema Environmental Change.
    Improving methane production using hydrodynamic cavitation as pre-treatment2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    To develop anaerobic digestion (AD), innovative solutions to increase methane yields in existing AD processes are needed. In particular, the adoption of low energy pre-treatments to enhance biomass biodegradability is needed to provide efficient digestion processes increasing profitability. To obtain these features, hydrodynamic cavitation has been evaluated as an innovative solutions for AD of waste activated sludge (WAS), food waste (FW), macro algae and grass, in comparison with steam explosion (high energy pre-treatment). The effect of these two pre-treatments on the substrates, e.g. particle size distribution, soluble chemical oxygen demand (sCOD), biochemical methane potential (BMP) and biodegradability rate, have been evaluated. After two minutes of hydrodynamic cavitation (8 bar), the mean fine particle size decreased from 489- 1344 nm to 277- 381 nm (≤77% reduction) depending of the biomasses. Similar impacts were observed after ten minutes of steam explosion (210 °C, 30 bar) with a reduction in particle size between 40% and 70% for all the substrates treated.  In terms of BMP value, hydrodynamic cavitation caused significant increment only within the A. nodosum showing a post treatment increment of 44% compared to the untreated value, while similar values were obtained before and after treatment within the other tested substrates. In contrast, steam explosion allowed an increment for all treated samples, A. nodosum (+86%), grass (14%) and S. latissima (4%). However, greater impacts where observed with hydrodynamic cavitation than steam explosion when comparing the kinetic constant K. Overall, hydrodynamic cavitation appeared an efficient pre-treatment for AD capable to compete with the traditional steam explosion in terms om kinetics and providing a more efficient energy balance (+14%) as well as methane yield for A. nodosum.

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  • 3.
    Acevedo Gomez, Yasna
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lindbergh, Göran
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Lagergren, Carina
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Applied Electrochemistry.
    Reformate from biogas used as fuel in a PEM fuel cell2013In: EFC 2013 - Proceedings of the 5th European Fuel Cell Piero Lunghi Conference, 2013, p. 163-164Conference paper (Refereed)
    Abstract [en]

    The performance of a PEM fuel cell can be easily degraded by introducing impurities in the fuel gas. Since reformate of biogas from olive mill wastes will contain at least one third of carbon dioxide, its influence was studied on a PtRu catalyst. A clean reformate gas for the anode (67% H2 and 33% CO2) without any traces of other compounds was used and electrochemical measurements showed that the performance of the fuel cell was hardly affected. However, diluting the hydrogen with higher amounts of CO2 will reduce the performance remarkably.

  • 4.
    Acuña, G. J.
    et al.
    Facultad de Ingeniería Sanitaria y Ambiental, Universidad Pontificia Bolivariana, Montería, Colombia.
    Berger, M.
    University of Liège, Dept. of Electrical Engineering and Computer Science, Liege, Belgium.
    Campana, Pietro Elia
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Campos, R. A.
    Universidade Federal De Santa Catarina, Departamento De Engenharia Civil, Florianopolis, Brazil.
    Canales, F. A.
    Department of Civil and Environmental, Universidad de la Costa, Barranquilla, Colombia.
    Cantor, D.
    Universidad Nacional De Colombia, Sede Medellín, Medellin, Colombia.
    Ciapała, B.
    AGH University of Science and Technology, Department of Fossil Fuels, Centre for Sustainable Development and Energy Efficiency, Krakow, Poland.
    Cioccolanti, L.
    eCampus University, Centro di Ricerca per l’Energia, l’Ambiente e il Territorio, Via Isimbardi 10, Novedrate, Italy.
    De Felice, M.
    European Commission, Joint Research Centre, Petten, Netherlands.
    de Oliveira Costa Souza Rosa, C.
    European Commission, Joint Research Centre, Petten, Netherlands.
    Teaching about complementarity - proposal of classes for university students - including exercises2022In: Complementarity of Variable Renewable Energy Sources, Elsevier , 2022, p. 687-713Chapter in book (Other academic)
    Abstract [en]

    The idea behind this chapter is to provide teachers and students with material that can be used while studying renewable energy sources with special attention paid to their complementary characteristics. The questions and exercises included below refer to chapters presented in the book. In case of any questions, we provide the readers with contact details to chapters corresponding authors who would be happy in assisting you in case of any queries.

  • 5.
    Ahmad, Waqar
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Coke-free conversion of benzene at high temperatures2023In: Journal of the Energy Institute, ISSN 1743-9671, E-ISSN 1746-0220, Vol. 109, article id 101307Article in journal (Refereed)
    Abstract [en]

    This study investigates the conversion of benzene in a novel highly non-porous ɣ-Al2O3 packed bed reactor at 1000–1100 °C. The influences of packed bed presence, reforming medium (steam and CO2), gas flow rate and benzene concentration on steady state benzene conversion are examined. In presence of packed bed, benzene conversions of 52, 75, and 84% were achieved with combined steam and CO2 reforming at 1000, 1050, and 1100 °C, respectively. Whereas, benzene conversion of 65% without the packed bed at 1000 °C experienced a continuous increase in differential upstream pressure (DUP) of high temperature (HT) filter at reactor downstream due to deposition of in situ generated coke. High concentrations of generated CO and H2 of 2.3 and 6 vol% with packed bed than 1.4 and 4.7 vol% without the packed respectively, were achieved. CO2 reforming achieved high benzene conversions of 68–98% than 42–80% achieved with stream reforming at packed bed reactor temperatures of 1000–1100 °C. The results indicated that presence of ɣ-Al2O3 packed bed with possible surface reactions directed the conversion of benzene to combustible gases instead of coke. Hence, ɣ-Al2O3 packed bed reactor could be a suitable choice for coke-free conversion of tar of gasifier producer gas.

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  • 6.
    Akinbomi, J G
    et al.
    Department of Chemical Engineering, Faculty of Engineering, Lagos State University, Lagos, 100268, Nigeria.
    Patinvoh, R J
    Department of Chemical Engineering, Faculty of Engineering, Lagos State University, Lagos, 100268, Nigeria.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Current challenges of high-solid anaerobic digestion and possible measures for its effective applications: a review2022In: Biotechnology for Biofuels and Bioproducts, E-ISSN 2731-3654, Vol. 15, no 1Article, review/survey (Refereed)
    Abstract [en]

    The attention that high solids anaerobic digestion process (HS-AD) has received over the years, as a waste management and energy recovery process when compared to low solids anaerobic digestion process, can be attributed to its associated benefits including water conservation and smaller digester foot print. However, high solid content of the feedstock involved in the digestion process poses a barrier to the process stability and performance if it is not well managed. In this review, various limitations to effective performance of the HS-AD process, as well as, the possible measures highlighted in various research studies were garnered to serve as a guide for effective industrial application of this technology. A proposed design concept for overcoming substrate and product inhibition thereby improving methane yield and process stability was recommended for optimum performance of the HS-AD process.

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  • 7.
    Al-Mamun, Abdullah
    et al.
    Sultan Qaboos University, Oman.
    Ahmad, Waqar
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Sultan Qaboos University, Oman.
    Jafary, Tahereh
    Sultan Qaboos University, Oman;International Maritime College, Oman.
    Nayak, Jagdeep Kumar
    Sultan Qaboos University, Oman.
    Al-Nuaimi, Ali
    Sultan Qaboos University, Oman.
    Sana, Ahmad
    Sultan Qaboos University, Oman.
    Recent advances in microbial electrosynthesis system: Metabolic investigation and process optimization2023In: Biochemical engineering journal, ISSN 1369-703X, E-ISSN 1873-295X, Vol. 196, article id 108928Article in journal (Refereed)
    Abstract [en]

    The intensified burning of fossil fuels and the discharging of industrial wastes are severe threats to the environment. The released CO2 and organic fractions of industrial and municipal wastes exacerbate global warming. Converting the released CO2 and organic wastes into beneficial electricity and biofuel-chemicals is deemed an environmental necessity. Microbial electrosynthesis (MES) presents a promising technology for bio-electrochemical conversion of released CO2 and organic wastes into electricity and biofuel-chemicals using external-powered and/or self-powered microbial oxidation/reduction processes. The MES system consists of anodic and cathodic processes. The technology mostly relies on the capacity of electron transfer from electroactive biofilm to the electrode for reducing organics into value-added chemicals and sustaining their respiration and growth. The current review aims to summarize and explore the diversified application of electrogenic microbes and their metabolic pathways of electron transfer. It also summarizes the MES reactor design and operational parameters that influence the catalysis of biofilm and hence, the system performance. The review concludes with a critical evaluation of technical challenges that should be overcome before large-scale implementation. Furthermore, various recommendations on technical perspectives for successful implementation and application, including future research directions, are presented in this study.

  • 8.
    Alvarado Ávila, María Isabel
    et al.
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    De Luca, Stefano
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Edlund, Ulrica
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Fibre- and Polymer Technology.
    Fei, Ye
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Dutta, Joydeep
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Cellulose as sacrificial agents for enhanced photoactivated hydrogen production2023In: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 7, no 8, p. 1981-1991Article in journal (Refereed)
    Abstract [en]

    The search for new energy sources together with the need to control greenhouse gas emissions has led to continued interest in low-emitting renewable energy technologies. In this context, water splitting for hydrogen production is a reasonable alternative to replace fossil fuels due to its high energy density producing only water during combustion. Cellulose is abundant in nature and as residuals from human activity, and therefore a natural, ecological, and carbon-neutral source for hydrogen production. In the present work, we propose a sustainable method for hydrogen production using sunlight and cellulose as sacrificial agents during the photocatalytic water splitting process. Platinum (Pt) catalyst activates hydrogen production, and parameters such as pH of the system, cellulose concentration, and Pt loading were studied. Using different biomasses, we found that the presence of hemicellulose and xyloglucan as part of the molecular composition considerably increased the H-2 production rate from 36 mu mol L-1 in one hour for rapeseed cellulose to 167.44 mu mol L-1 for acid-treated cellulose isolated from Ulva fenestrata algae. Carboxymethylation and TEMPO-oxidation of cellulosic biomass both led to more stable suspensions with higher rates of H-2 production close to 225 mu mol L-1, which was associated with their water solubility properties. The results suggest that cellulosic biomass can be an attractive alternative as a sacrificial agent for the photocatalytic splitting of water for H-2 production.

  • 9.
    Alvfors, Per
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Arnell, Jenny
    IVL.
    Berglin, Niklas
    Innventia.
    Björnsson, Lovisa
    LU.
    Börjesson, Pål
    LU.
    Grahn, Maria
    Chalmers/SP.
    Harvey, Simon
    Chalmers.
    Hoffstedt, Christian
    Innventia.
    Holmgren, Kristina
    IVL.
    Jelse, Kristian
    IVL.
    Klintbom, Patrik
    Kusar, Henrik
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Lidén, Gunnar
    LU.
    Magnusson, Mimmi
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Pettersson, Karin
    Chalmers.
    Rydberg, Tomas
    IVL.
    Sjöström, Krister
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Stålbrand, Henrik
    LU.
    Wallberg, Ola
    LU.
    Wetterlund, Elisabeth
    LiU.
    Zacchi, Guido
    LU.
    Öhrman, Olof
    ETC Piteå.
    Research and development challenges for Swedish biofuel actors – three illustrative examples: Improvement potential discussed in the context of Well-to-Tank analyses2010Report (Other academic)
    Abstract [en]

    Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use. Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology. In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study. We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose. From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.

  • 10.
    Amiandamhen, Stephen
    et al.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Kumar, Anuj
    Natural Resources Institute Finland (Luke), Finland.
    Adamopoulos, Stergios
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Jones, Dennis
    Luleå university of technology, Sweden;Czech university of life sciences Prague, Czech Republic.
    Nilsson, Bengt
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Bioenergy production and utilization in different sectors in Sweden: A state of the art review2020In: BioResources, E-ISSN 1930-2126, Vol. 15, no 4, p. 9834-9857Article in journal (Refereed)
    Abstract [en]

    In the continual desire to reduce the environmental footprints of human activities, research efforts to provide cleaner energy is increasingly becoming vital. The effect of climate change on present and future existence, sustainable processes, and utilizations of renewable resources have been active topics within international discourse. In order to reduce the greenhouse gases emissions from traditional materials and processes, there has been a shift to more environmental friendly alternatives. The conversion of biomass to bioenergy, including biofuels has been considered to contribute to the future of climate change mitigation, although there are concerns about carbon balance from forest utilization. Bioenergy accounts for more than one-third of all energy used in Sweden and biomass has provided about 60% of the fuel for district heating. Apart from heat and electricity supply, the transport sector, with about 30% of global energy use, has a significant role in a sustainable bioenergy system. This review presents the state of the art in the Swedish bioenergy sector based on literature and Swedish Energy Agency’s current statistics. The review also discusses the overall bioenergy production and utilization in different sectors in Sweden. The current potential, challenges, and environmental considerations of bioenergy production are also discussed

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  • 11.
    Anacleto, Thuane Mendes
    et al.
    Univ Fed Rio de Janeiro, Brazil; Univ Fed Rio de Janeiro, Brazil.
    Kozlowsky-Suzuki, Betina
    Fed Univ State Rio De Janeiro, Brazil; Fed Univ State Rio De Janeiro, Brazil; Fed Univ State Rio De Janeiro, Brazil.
    Björn (Fredriksson), Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Solutions Research Center.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Solutions Research Center.
    Masuda, Laura Shizue Moriga
    Ch Mendes Inst Biodivers Conservat ICMBio, Brazil.
    de Oliveira, Vinicius Peruzzi
    Univ Fed Rio de Janeiro, Brazil.
    Enrich Prast, Alex
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Solutions Research Center. Univ Fed Rio de Janeiro, Brazil; Fed Univ Sao Paulo IMar UNIFESP, Brazil.
    Methane yield response to pretreatment is dependent on substrate chemical composition: a meta-analysis on anaerobic digestion systems2024In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, no 1, article id 1240Article in journal (Refereed)
    Abstract [en]

    Proper pretreatment of organic residues prior to anaerobic digestion (AD) can maximize global biogas production from varying sources without increasing the amount of digestate, contributing to global decarbonization goals. However, the efficiency of pretreatments applied on varying organic streams is poorly assessed. Thus, we performed a meta-analysis on AD studies to evaluate the efficiencies of pretreatments with respect to biogas production measured as methane yield. Based on 1374 observations our analysis shows that pretreatment efficiency is dependent on substrate chemical dominance. Grouping substrates by chemical composition e.g., lignocellulosic-, protein- and lipid-rich dominance helps to highlight the appropriate choice of pretreatment that supports maximum substrate degradation and more efficient conversion to biogas. Methane yield can undergo an impactful increase compared to untreated controls if proper pretreatment of substrates of a given chemical dominance is applied. Non-significant or even adverse effects on AD are, however, observed when the substrate chemical dominance is disregarded.

  • 12.
    Andersson, Henny
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lindmark, Johan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Jansson, Joakim
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Suhonen, Anssi
    Savonia University of Applied Sciences.
    Jääskeläinen, Ari
    Savonia University of Applied Sciences.
    Reijonen, Tero
    Savonia University of Applied Sciences.
    Laatikainen, Reino
    University of Eastern Finland.
    Heitto, Anneli
    Finnoflag.
    Hakalehto, Elias
    Finnoflag.
    Technical Output Report – Pilot A in Sweden2014Report (Other academic)
  • 13.
    Andersson, Jim
    et al.
    Luleå University of Technology, Sweden.
    Lundgren, Joakim
    Luleå University of Technology, Sweden.
    Malek, Laura
    Lund University, Sweden.
    Hultegren, Christian
    Lund University, Sweden.
    Pettersson, Karin
    Chalmers University of Technology, Gothenburg, Sweden.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    System studies on biofuel production via integrated biomass gasification2013Report (Other academic)
    Abstract [en]

    A large number of national and international techno-economic studies on industrially integrated gasifiers for production of biofuels have been published during the recent years. These studies comprise different types of gasifiers (fluidized bed, indirect and entrained flow) integrated in different industries for the production of various types of chemicals and transportation fuels (SNG, FT-products, methanol, DME etc.) The results are often used for techno-economic comparisons between different biorefinery concepts. One relatively common observation is that even if the applied technology and the produced biofuel are the same, the results of the techno-economic studies may differ significantly.

    The main objective of this project has been to perform a comprehensive review of publications regarding industrially integrated biomass gasifiers for motor fuel production. The purposes have been to identify and highlight the main reasons why similar studies differ considerably and to prepare a basis for “fair” techno-economic comparisons. Another objective has been to identify possible lack of industrial integration studies that may be of interest to carry out in a second phase of the project.

    Around 40 national and international reports and articles have been analysed and reviewed. The majority of the studies concern gasifiers installed in chemical pulp and paper mills where black liquor gasification is the dominating technology. District heating systems are also well represented. Only a few studies have been found with mechanical pulp and paper mills, steel industries and the oil refineries as case basis. Other industries have rarely, or not at all, been considered for industrial integration studies. Surprisingly, no studies regarding integration of biomass gasification neither in saw mills nor in wood pellet production industry have been found.

    There are several reasons why the results of the reviewed techno-economic studies vary. Some examples are that different system boundaries have been set and that different technical and economic assumptions have been made, product yields and energy efficiencies may be calculated using different methods etc. For obvious reasons, the studies are not made in the same year, which means that different monetary exchange rates and indices have been applied. It is therefore very difficult, and sometimes even impossible, to compare the technical as well as the economic results from the different studies. When technical evaluations are to be carried out, there is no general method for how to set the system boundaries and no right or wrong way to calculate the system efficiencies as long as the boundaries and methods are transparent and clearly described. This also means that it becomes fruitless to compare efficiencies between different concepts unless the comparison is done on an exactly equal basis.

    However, even on an equal basis, a comparison is not a straight forward process. For example, calculated efficiencies may be based on the marginal supply, which then become very dependent on how the industries exploit their resources before the integration. The resulting efficiencies are therefore very site-dependent. Increasing the system boundaries to include all in- and outgoing energy carriers from the main industry, as well as the integrated gasification plant (i.e. total plant mass and energy balance), would inflict the same site-dependency problem. The resulting system efficiency is therefore a measure of the potential improvement that a specific industry could achieve by integrating a biomass gasification concept.

    When estimating the overall system efficiency of industrial biorefinery concepts that include multiple types of product flows and energy sources, the authors of this report encourage the use of electrical equivalents as a measure of the overall system efficiency. This should be done in order to take the energy quality of different energy carriers into concern.

    In the published economic evaluations, it has been found that there is a large number of studies containing both integration and production cost estimates. However, the number of references for the cost data is rather limited. The majority of these have also been published by the same group of people and use the same or similar background information. The information in these references is based on quotes and estimates, which is good, however none of these are publically available and therefore difficult to value with respect to content and accuracy.

    It has further been found that the variance in the operational costs is quite significant. Something that is particularly true for biomass costs, which have a high variance. This may be explained by natural variations in the quality of biomass used, but also to the different markets studied and the dates when the studies were performed. It may be seen from the specific investment costs that there is a significant spread in the data. It may also be seen that the differences in capital employed and process yields will result in quite large variations in the production cost of the synthetic fuels. On a general note, the studies performed are considering future plants and in some cases assumes technology development. It is therefore relevant to question the use of today’s prices of utilities and feedstock’s. It is believed that it would be more representative to perform some kind of scenario analysis using different parameters resulting in different cost assumptions to better exemplify possible futures.

    Due to the surprising lack of reports and articles regarding integration of biomass gasifiers in sawmills, it would be of great interest to carry out such a study. Also larger scale wood pellet production plants could be of interest as a potential gasification based biorefinery.

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  • 14.
    Andersson Schönn, Mikael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Promoter regulation: designing cells for biotechnological applications2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The filamentous cyanobacteria Nostoc punctiforme ATCC 29133 is a model species fordevelopment of sustainable production methods of numerous compounds. One of its uniquefeatures is the anaerobic environment of the strains nitrogen fixing heterocyst cells. To be ableto properly utilize this environment, more knowledge regarding what regulates cell specificexpression is required. In this study, three motifs of the NsiR I promoter of Anabaena sp.PCC 7120 was studied in this system utilizing YFP-fluorescence as a reporter to determinetheir impact on spatial expression pattern. Investigations were performed on immobilizedcells with the use of confocal microscopy and results point towards sigma factor regulation.

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  • 15.
    Andersson, Simon
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Environmental and Life Sciences.
    Pellet production of Sicklebush, Pigeon Pea, and Pine in Zambia: Pilot Study and Full Scale Tests to Evaluate Pellet Quality and Press Configurations2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    More deaths are caused every year by indoor air pollution than malaria, HIV/AIDS and tuberculosis combined. Cooking with traditional fuels such as charcoal and fuelwood with poor ventilation causes the single most important environmental health risk factor worldwide. It also contributes to environmental issues such as deforestation as traditional biomass fuels and cooking stoves are inefficient and requires large quantities of wood. This is especially critical in Africa where the largest regional population growth in the world is expected to occur.

    A solution to these issues was realized through fuel pellets and modern cooking stoves by Emerging Cooking Solutions, a company started by two Swedes and based in Zambia. The production of fuel pellets in Zambia is dependent on pine sawdust from small sawmills and is a declining source of raw material. However, other sources of biomass are available in Zambia such as pigeon pea stalk, an agricultural waste product, and sicklebush, an invasive tree species. If these species are viable for pelletization, the production of pellets can increase while reducing issues with sicklebush and promoting cultivation of pigeon pea. The aim of this work is to evaluate if pigeon pea stalk and sicklebush are viable to pelletize in Zambia and how the press is affected by the different raw materials.

    A pilot study is done at Karlstad University with a single unit press, hardness tester and soxhlet extractor to evaluate how the material constituents correlate to friction in the press channel and hardness of the pellets. The results of the pilot study provide support for full scale tests done in a pellet plant in Zambia. The normal production of pellets from pine sawdust is used as quality and production reference for the tests with pigeon pea stalk, sicklebush, and different mixes of the raw materials. The properties used to evaluate the quality of the pellets are hardness, durability, moisture content, bulk density, and fines. The press configuration is evaluated by logging the electricity consumption by the press motor, calculating the power and specific energy consumption from the logs, and observations during the tests.

    The results show that sicklebush, and mixes of sicklebush with pigeon pea stalk can produce pellets with better quality than the reference pine pellets. An interesting composition is a mix of 80% pigeon pea and 20% sicklebush that produces pellets with the best quality of all the tests. However, pellets produced from sicklebush and pigeon pea show a larger variation in hardness as compared to the reference pellets from pine sawdust. Mixing pigeon pea with pine reduces these variations but reduces the hardness of the pellets below the reference. The press struggles to process sicklebush and pigeon pea stalk with fluctuating power consumption that causes the motor to trip. The inhomogeneity of the materials in sicklebush and pigeon pea are identified to cause the issues in the press. Production improvements are discussed to facilitate the production of pigeon pea stalk and sicklebush pellets.

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  • 16.
    Anukam, Anthony Ike
    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).
    Bosede Famewo, Elisabeth
    University of Fort Harare, South Africa.
    Nyamukamba, Pardon
    Cape Peninsula University, South Africa.
    Characterization of pure and blended pellets made from Norway spruce and pea starch: A comparative study of bonding mechanism relevant to quality2019In: Energies, E-ISSN 1996-1073, Vol. 12, no 23, p. 1-22, article id 4415Article in journal (Refereed)
    Abstract [en]

    The mechanism of bonding in biomass pellets is such a complex event to comprehend, as the nature of the bonds formed between combining particles and their relevance to pellet quality are not completely understood. In this study, pure and blended biomass pellets made from Norway spruce and pea starch were characterized using advanced analytical instruments able to provide information beyond what is visible to the human eye, with intent to investigate differences in bonding mechanism relevant to quality. The results, which were comprehensively interpreted from a structural chemistry perspective, indicated that, at a molecular level, the major disparity in bonding mechanism between particles of the pellets and the quality of the pellets, defined in terms of strength and burning efficiency, were determined by variation in the concentration of polar functional groups emanating from the major organic and elemental components of the pellets, as well as the strength of the bonds between atoms of these groups. Microscopic-level analysis, which did not provide any clear morphological features that could be linked to incongruity in quality, showed fracture surfaces of the pellets and patterns of surface roughness, as well as the mode of interconnectivity of particles, which were evidence of the production of pellets with dissimilarities in particle bonding mechanism and visual appearance.

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  • 17.
    Asuquo, Asuquo Jackson
    et al.
    University of Strathclyde, UK.
    Zhang, Xiaolei
    University of Strathclyde, UK.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Li, Jun
    University of Strathclyde, UK.
    Green heterogeneous catalysts derived from fermented kola nut pod husk for sustainable biodiesel production2024In: International Journal of Green Energy, ISSN 1543-5075, E-ISSN 1543-5083Article in journal (Refereed)
    Abstract [en]

    The use of green heterogeneous catalysts that are obtained from waste agricultural biomass can make the production of biodiesel more economical. In this research, three solid base heterogeneous catalysts (Catalyst A, B, and C) were synthesized from kola nut pod husks, and the synergistic effects of the elemental composition on catalytic activities for biodiesel production were studied. The results revealed a high surface area of Catalysts A, B, and C at 419.90 m2/g, 430.54 m2/g, and 432.57 m2/g, respectively. Their corresponding pore diameters are 3.53 nm, 3.48 nm, and 3.32 nm, showing that the catalysts are mesoporous in nature. The X-ray Fluorescence (XRF) results revealed the presence of a variety of alkaline earth metals and their corresponding metal oxides in substantial amounts. Catalyst A was produced with the highest concentration of calcium at 40.84 wt.% and calcium oxide at 68.02 mole%. The substantial concentration of other elements, such as potassium, magnesium, and aluminum, and their corresponding metal oxides are the proof of high catalytic activity of the produced green catalysts. The high CaO contents of all three produced catalysts and their high surface areas indicate their strong potential for good catalytic activities applied to the synthesis of biodiesel.

  • 18.
    Atat, Rachad
    et al.
    KTH, School of Information and Communication Technology (ICT), Communication Systems, CoS, Radio Systems Laboratory (RS Lab).
    Yaacoub, E.
    Alouini, M. -S
    Abu-Dayya, A.
    Peer-to-peer content sharing techniques for energy efficiency in wireless networks with fast channel variations2013In: Green Networking and Communications: ICT for Sustainability, CRC Press , 2013, p. 3-28Chapter in book (Other academic)
    Abstract [en]

    According to the International Telecommunication Union, information and communication technology (ICT) was emitting 0.83 GtCO2e (gigatons of carbon dioxide equivalent), contributing to around 2%-2.5% of global greenhouse gas (GHG) emissions in 2007 [1]. With the continuous growth of ICT, especially in developing countries, the GHG emissions are expected to grow at double the rate over the next 10 years [1]. The Global e-Sustainability Initiative research is estimating a 72% increase in ICT energy usage from 2007 to 2020 with around 1.43 GtCO2e emissions in 2020 [1]. In addition, the telecommunications industry is witnessing an explosive increase in data traffic especially with the introduction of wireless modems and smart phones and with the presence of more than one billion wireless subscribers today. The data traffic volume is increasing by a factor of 10 every 5 years, leading to an increase of 16%-20% in energy consumption every 5 years [2]. For instance, in India, the mobile telecom industry is considered the fastest-growing sector with 584.3 million subscribers in 2010-2011 with an annual growth rate of 49.15%. It is estimated that the energy consumption of the Indian Mobile Telecom Industry was 163 PJ (petajoules) with 52.66 million tons emissions of carbon dioxide (CO2) in 2010-2011 [3]. A user who travels a distance of 25 km using public transport such as car or train can result in 1.22 kg of CO2 emissions, compared to 0.11 kg of CO2 emissions for 1 hour of video conferencing with two laptops [4]. A talk of 2 minutes per day on the phone can produce 47 kg CO2e (equivalent) per year, with a total of 125 million tons of CO2e produced by mobile phones in 1 year [5]. 

  • 19.
    Awasthi, S K
    et al.
    College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi Province, PR China.
    Kumar, M
    CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur, 440020, Maharashtra, India.
    Sarsaiya, S
    Key Laboratory of Basic Pharmacology and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, Guizhou, China.
    Ahluwalia, V
    Institute of Pesticide Formulation Technology, Gurugram, Haryana, 122 016, India.
    Chen, H Y
    Institute of Biology, Freie Universität Berlin, Altensteinstr. 6, Berlin, 14195, Germany.
    Kaur, G
    Department of Civil Engineering, Lassonde School of Engineering, York University, Toronto, ON, M3J 1P3, Canada.
    Sirohi, R
    Department of Chemical and Biological Engineering, Korea University, Seoul, South Korea.
    Sindhu, R
    Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram, Kerala, 695019, India.
    Binod, P
    Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Thiruvananthapuram, Kerala, 695019, India.
    Pandey, A
    Centre for Innovation and Translational Research, CSIR-Indian Institute of Toxicology Research, Lucknow, 226 001, India.
    Rathour, R
    CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur, 440020, Maharashtra, India.
    Kumar, S
    CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur, 440020, Maharashtra, India.
    Singh, L
    CSIR-National Environmental Engineering Research Institute (CSIR-NEERI), Nehru Marg, Nagpur, 440020, Maharashtra, India.
    Zhang, Z Q
    College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi Province, PR China.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Awasthi, M K
    College of Natural Resources and Environment, Northwest A&F University, Yangling, 712100, Shaanxi Province, PR China.
    Multi-criteria research lines on livestock manure biorefinery development towards a circular economy: From the perspective of a life cycle assessment and business models strategies2022In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 341, article id 130862Article in journal (Refereed)
    Abstract [en]

    Livestock manure (LSM) is a profitable waste if handled sensibly, but simultaneously it imposes several environmental and health impacts if managed improperly. Several approaches have been adopted globally to cartel the problem associated with LSM management and recovery of value-added products, still, technological innovation needs further upgradation in consideration with the environment, energy, and economy. This review delivered a vibrant portrait of manure management, which includes, bioenergy generation and resource recovery strategies, their current scenario, opportunities, challenges, and prospects for future researches along with global regulations and policies. Several bioenergy generation and nutrient recoveries technologies have been discussed in details, still, the major glitches allied with these technologies are its high establishment costs, operational costs, manure assortment, and digestate handling. This review also discussed the techno-economic assessment (TEA) and life cycle assessment (LCA) of LSM management operation in the context of their economical and environmental sustainability. Still, extensive researches needed to build an efficient manure management framework to advance the integrated bioenergy production, nutrients recycling, and digestate utilization with least environmental impacts and maximal economical gain, which has critically discussed in the current review.

  • 20.
    Bahena, Rodrigo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Energy recovery through anaerobic co-digestion of food waste and wastewater treatment sludge: A proposition of a water treatment and biogas plant for a floating island in Stockholm.2022Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The urge for more sustainable living motivated the Stockholm Tiny House Expo. The project aims to build a floating, sustainable, man-made island for living and working outside of Stockholm. This paper proposes a waste management method with possible energy recovery for the island. It introduces a comprehensive system that integrates decentralized wastewater treatment with energy generation through anaerobic treatment. A by-product of the wastewater treatment process, the sludge, is combined with food waste to generate energy through biogas. The island’s organic waste (wastewater and food waste) is thereby managed sustainably. The results of this report require further research. The energy supply from the biogas reactor was calculated to be 52.19 MWh. The wastewater treatment process was designed with an objective of 90% reduction of BOD5, to comply with the Swedish regulations for wastewater discharge to natural bodies of water, including the ocean. The system's total volume proposed is 11.25 m3, which is the sum of the volumes of all the reactors, or tanks, needed to complete the treatment. 

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  • 21.
    Bajracharya, Suman
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Sarkar, Omprakash
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Krige, Adolf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Matsakas, Leonidas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Chapter 12 - Advances in gas fermentation processes2022In: Current Developments in Biotechnology and Bioengineering: Advances in Bioprocess Engineering / [ed] Sirohi, Ranjna; Pandey, Ashok; Taherzadeh, Mohammad J.; Larroche, Christian, Elsevier, 2022, p. 321-351Chapter in book (Other academic)
    Abstract [en]

    Microbial metabolism enables the sustainable synthesis of fuels and chemicals from gaseous substrates (H2, CO, and CO2), thus drastically diminishing the carbon load in the atmosphere. Various value-added biochemicals and biofuels, such as acetate, methane, ethanol, butanol, butyrate, caproate, and bioplastics, have been produced during the conversion of syngas or H2/CO2, using a variety of microorganisms as biocatalysts. Gas fermentation processes using acetogenic and methanogenic organisms are being extensively investigated. This chapter provides an overview of microbial CO and CO2 conversion technology, with an emphasis on recent developments and integration with renewable electricity for the generation of H2 or other forms of electron donors. A discussion on technological challenges in gas fermentation addresses issues, such as poor mass transfer, low microbial biomass, and low productivity. It also presents possible solutions based on the latest advances in bioelectrochemical processes including microbial gas electrofermentation. Finally, the chapter includes a sustainability analysis of the process and includes a brief update on commercially established companies operating gas fermentation systems. Overall, an integrated approach combining gas fermentation and renewable electricity offers an opportunity for the development of CO and CO2- based biochemical and biofuel production at commercial scale.

  • 22. Barbero-López, A.
    et al.
    López-Gómez, Y. M.
    Carrasco, J.
    Jokinen, N.
    Lappalainen, R.
    Akkanen, J.
    Mola-Yudego, B.
    Haapala, Antti
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Mathematics, and Science Education (2023-). University of Eastern Finland.
    Characterization and antifungal properties against wood decaying fungi of hydrothermal liquefaction liquids from spent mushroom substrate and tomato residues2024In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 181, article id 107035Article in journal (Refereed)
    Abstract [en]

    This study aimed to investigate the potential of converting bio-based residues from industrial production of mushrooms and tomatoes into more valuable chemicals with antifungal properties using hydrothermal liquefaction (HTL). Liquid fractions were obtained from HTL of spent substrate of Agaricus bisporus (Lange) Imbach and Pleurotus ostreatus (jacq.) P. kumm., recomposted Agaricus bisporus spent substrate, and tomato residues. The quantitative 1H NMR spectroscopy analysis revealed that the HTL liquids of all residues contained antifungal constituents like phenols and organic acids. The HTL liquids at dilutions of 10 % were able to inhibit the fungi by over 80 %. Interestingly, the fungus P. ostreatus showed tolerance to these constituents as its growth was promoted at the lowest concentration of all the HTL liquids. The HTL liquids had lower ecotoxicity than the commercial wood preservative. These results suggest that the tested residues could be a promising source of preservative chemical constituents for the wood industry. 

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  • 23.
    Basu, Alex
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Biology Education Centre.
    Relation between hydrogen production and photosynthesis in the green algae Chlamydomonas reinhardtii2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The modernized world is over-consuming low-cost energy sources that strongly contributes to pollution and environmental stress. As a consequence, the interest for environmentally friendly alternatives has increased immensely. One such alternative is the use of solar energy and water as a raw material to produce biohydrogen through the process of photosynthetic water splitting. In this work, the relation between H2-production and photosynthesis in the green algae Chlamydomonas reinhardtii was studied with respect to three main aspects: the establishment of prolonged H2-production, the involvement of PSII in H2-production and the electron pathways associated with PSII during H2-production. For the first time, this work reveals that PSII plays a crucial role throughout the H2-producing phase in sulfur deprived C. reinhardtii. It further reveals that a wave-like fluorescence decay kinetic, before only seen in cyanobacteria, is observable during the H2-producing phase in sulfur deprived C. reinhardtii, reflecting the presence of cyclic electron flows also in green algae. 

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  • 24.
    Bekele, Wondimagegne
    et al.
    Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden; Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.
    Huhtanen, Pekka
    Production Systems, Natural Resources Institute Finland (LUKE), Jokioinen, Finland.
    Zegeye, Abiy
    Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.
    Simachew, Addis
    Institute of Biotechnology, Addis Ababa University, Addis Ababa, Ethiopia.
    Siddique, Abu Bakar
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Albrectsen, Benedicte Riber
    Umeå University, Faculty of Science and Technology, Department of Plant Physiology. Umeå University, Faculty of Science and Technology, Umeå Plant Science Centre (UPSC).
    Ramin, Mohammad
    Department of Applied Animal Science and Welfare, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden.
    Methane production from locally available ruminant feedstuffs in Ethiopia: an in vitro study2024In: Animal Feed Science and Technology, ISSN 0377-8401, E-ISSN 1873-2216, Vol. 312, article id 115977Article in journal (Refereed)
    Abstract [en]

    Achieving optimal nutrient composition in locally sourced ruminant feeds is important, but can be challenging in resource-limited production systems. For example, improving the composition of available local feed resources is a key obstacle to efficiently mitigating enteric methane (CH4) emissions in ruminants. This study characterized the nutritional content and in vitro methane (CH4) yield of ruminant feedstuffs accessible in Ethiopia. A survey of 60 experienced farmers in two representative districts in Amhara region, Ethiopia, provided 33 feed samples, which were classified into four ruminant feed categories: Grasses (n=10); indigenous plants (trees, shrubs, herbaceous plants) (n=13); crop residues (n=5); and agro-industrial by-products (n=5). Nutritional composition was assessed by proximate and detergent methods. Methane yield (g CH4/kg feed dry matter (DM)) and total gas yield (L/kg DM) were evaluated using a fully automated in vitro gas production system. A colorimetric assay was conducted to measure condensed tannin content (CT, mg/g) in relevant feeds. Lower crude protein (CP) values were observed for the grass (mean 65.2 g/kg DM) and crop residues (mean 54.5 g/kg DM) categories. Agro-industrial by-products had the highest CP (mean 260 g/kg DM), while indigenous plants exhibited intermediate levels (163 g/kg DM). There was significant variation in CH4 yield (P<0.01) between grasses (12.4–24.7 g/kg DM) indigenous plants (1.8–19.3 g/kg DM), and agro-industrial by-products (8.1–26.9 g/kg DM). The indigenous plant Trifolium acaule gave the lowest in vitro CH4 yield (1.8 g/kg DM). A positive relationship was observed between in vitro dry matter digestibility (IVDMD), CH4, and total gas yield. Percentage of CH4 in total gas production varied with feed category (grasses 14.5–19.6%; indigenous plants 3.1–16.9%; crop residues 15.8–20.6%; agro-industrial by-products 12.8–18.7%), and within category, e.g., Trifolium acaule (3.1%), Acacia nilotica L. (7.1%), Ziziphus spina-christi (9.9%), brewer's spent grains (BSG) (12.8%), local liquor (areki) residues (14.1%), and local beer (tella) residues (15.1%). A negative relationship was observed between CT content and in vitro CH4 yield, with a stronger (P<0.05) correlation for soluble CTs (R2 = 0.46) than cell-bound CTs (R2 = 0.25) and total CTs (R2 = 0.29). Based on methanogenic properties and effects of CTs on in vitro CH4 yield, indigenous plants should be prioritized in ruminant rations in Ethiopia. Making nutritional composition and CH4 data publicly available could help develop environmentally sound, cost-effective rations for ruminant livestock, benefiting local farmers and leading to more sustainable and efficient livestock production in Ethiopia.

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  • 25.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kullendorff, Anders
    Biobränsletorkning - en lägesrapport projektet Fluidtork1996Report (Other academic)
  • 26. Bergström, Dan
    et al.
    Israelsson, Samuel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Öhman, Marcus
    Dahlqvist, Sten-Axel
    Gref, Rolf
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Wästerlund, Iwan
    Effects of raw material particle size distribution on the characteristics of Scots pine sawdust fuel pellets2008In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 89, no 12, p. 1324-1329Article in journal (Refereed)
    Abstract [en]

    In order to study the influence of raw material particle size distribution on the pelletizing process and the physical and thermomechanical characteristics of typical fuel pellets, saw dust of Scots pine was used as raw material for producing pellets in a semi industrial scaled mill (similar to 300 kg h(-1)). The raw materials were screened to a narrow particle size distribution and mixed into four different batches and then pelletized under controlled conditions. Physical pellet characteristics like compression strength, densities, moisture content, moisture absorption and abrasion resistance were determined. In addition, the thermochemical characteristics, i.e. drying and initial pyrolysis, flaming pyrolysis, char combustion and char yield were determined at different experimental conditions by using a laboratory-scaled furnace. The results indicate that the particle size distribution had some effect on current consumption and compression strength but no evident effect on single pellet and bulk density, moisture content, moisture absorption during storage and abrasion resistance. Differences in average total conversion time determined for pellet batches tested under the same combustion conditions was less than 5% and not significant. The results are of practical importance suggesting that grinding of saw dust particle sizes below 8 mm is probably needless when producing softwood pellets. Thus it seem that less energy could be used if only over sized particles are grinded before pelletizing.

  • 27. Bergström, Dan
    et al.
    Israelsson, Samuel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Öhman, Marcus
    Dahlqvist, Sten-Axel
    Gref, Rolf
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Wästerlund, Iwan
    Effects of raw material particle size distribution on the characteristics of Scots pine sawdust fuel pellets2008In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 89, no 12, p. 1324-1329Article in journal (Refereed)
    Abstract [en]

    In order to study the influence of raw material particle size distribution on the pelletizing process and the physical and thermomechanical characteristics of typical fuel pellets, saw dust of Scots pine was used as raw material for producing pellets in a semi industrial scaled mill (similar to 300 kg h(-1)). The raw materials were screened to a narrow particle size distribution and mixed into four different batches and then pelletized under controlled conditions. Physical pellet characteristics like compression strength, densities, moisture content, moisture absorption and abrasion resistance were determined. In addition, the thermochemical characteristics, i.e. drying and initial pyrolysis, flaming pyrolysis, char combustion and char yield were determined at different experimental conditions by using a laboratory-scaled furnace. The results indicate that the particle size distribution had some effect on current consumption and compression strength but no evident effect on single pellet and bulk density, moisture content, moisture absorption during storage and abrasion resistance. Differences in average total conversion time determined for pellet batches tested under the same combustion conditions was less than 5% and not significant. The results are of practical importance suggesting that grinding of saw dust particle sizes below 8 mm is probably needless when producing softwood pellets. Thus it seem that less energy could be used if only over sized particles are grinded before pelletizing.

  • 28.
    Bergström, Maria
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013). Karlstad Universitet.
    Pyrolysolja som bränsle för fjärrvärmeproduktion samt råvara till biodrivmedel: Egenskaper och prestanda vid lagring, förbränning och uppgradering2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    For Sweden to reach the goal of zero net emissions of greenhouse gases by the year 2045, more use of biofuels and less use of fossil fuels is needed and for this we need higher production and more options of biofuels. One option is pyrolysis oil which has been in research since the 1970’s but was only recently introduced to large-scale heat production. Also, this year Pyrocell have started the construction of a pyrolysis plant where the pyrolysis oil is going to be upgraded to biofuels. The pyrolysis oil has different properties and composition compared to other biooils and fossil oils. For example, it has high water content, high viscosity and high content of oxygenated compounds which makes the oil more difficult to handle, unstable and gives the oil a low heating value.

    Karlstads Energi AB has started a project to evaluate an integrated pyrolysis reactor to one of their existing combined heat and power plants with the objective to produce pyrolysis oil in the future. They are interested in using the pyrolysis oil as a fuel in two of their reserve boilers for district heating production and to sell as raw material to the fuel industry. The object of this study is to investigate the possibility of using the pyrolysis oil at Karlstads Energi in the meaning of properties, aging, combustion and upgrading to biofuel and to compare the properties and combustion performance with the fuel they are using today, bio100. The goals are to; (1) map and compare the properties and composition of pyrolysis oil with bio100 from literature, (2) calculate and estimate changes of viscosity and storage- and atomization temperatures of fresh and stored pyrolysis oil using data from literature, (3) calculate combustion properties and combustion performance at 30 MW power outlet from the boiler through simulation in Chemcad and a heat transfer-model in Excel and (4) investigate the possibility to upgrade pyrolysis oil to biofuel through theoretical calculation of hydrogen consumption and biofuel yield. The pyrolysis oil is investigated with 25, 15 and 8 wt% water and addition of 5 and 10 wt% methanol and ethanol to stabilize the oil and to improve the combustion.

    The results shows that a pyrolysis oil with 8 wt% water could have too high viscosity to be able to be pumped and combusted in reasonable temperatures while 26 and 15 wt% water have lower viscosity and can be used in reasonable temperatures, both with and without addition of alcohol. At combustion with 30 MW power output the flow of pyrolysis oil and flue gases is 1,9-2,6 times and 1,05-1,21 times higher than bio100, respectively (3250 kg/h and 42900 m3/h, respectively for bio100). This means that the facility could be undersized to be able to get 30 MW power output with pyrolysis oil, where the oil flow probably is the limiting factor. This requires further investigation of the equipment. The air-fuel-ratio to receive 4% excess oxygen in the flue gases for the pyrolysis oils is about half of that of bio100 (6,7-8,6 compared to 16 kg air/kg oil, respectively). The emissions of dust and NOx are high for the pyrolysis oils because of high content of ash and nitrogen and will probably exceed the future limitations of which measures will be needed. The efficiency (based on higher heating value) for pyrolysis oil with 8 wt% water and 10 wt% ethanol can reach the same efficiency as bio100 (91%), while 26 and 15 wt% water content reach 84 and 88%, respectively. The theoretical hydrogen consumption and biofuel yield were calculated to 575-775 L hydrogen/kg pyrolysis oil and 45-62%, respectively. Overall, addition of methanol is a better choice for the viscosity, but ethanol performs better in combustion and upgrading to biofuels.

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  • 29.
    Bhatt, Puja
    et al.
    Central Department of Biotechnology, Tribhuvan University, Kirtipur 44618, Nepal.
    Poudyal, Pranita
    Central Department of Biotechnology, Tribhuvan University, Kirtipur 44618, Nepal.
    Dhungana, Pradip
    Central Department of Biotechnology, Tribhuvan University, Kirtipur 44618, Nepal.
    Prajapati, Bikram
    Central Department of Biotechnology, Tribhuvan University, Kirtipur 44618, Nepal.
    Bajracharya, Suman
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Yadav, Amar Prasad
    Central Department of Chemistry, Tribhuvan University, Kirtipur 44618, Nepal.
    Bhattarai, Tribikram
    Central Department of Biotechnology, Tribhuvan University, Kirtipur 44618, Nepal.
    Sreerama, Lakshmaiah
    Central Department of Biotechnology, Tribhuvan University, Kirtipur 44618, Nepal; Department of Chemistry and Biochemistry, St. Cloud State University, St. Cloud, MN 56301, USA.
    Joshi, Jarina
    Central Department of Biotechnology, Tribhuvan University, Kirtipur 44618, Nepal.
    Enhancement of Biogas (Methane) Production from Cow Dung Using a Microbial Electrochemical Cell and Molecular Characterization of Isolated Methanogenic Bacteria2024In: Biomass, E-ISSN 2673-8783, Vol. 4, no 2, p. 455-471Article in journal (Refereed)
    Abstract [en]

    Biogas has long been used as a household cooking fuel in many tropical counties, and it has the potential to be a significant energy source beyond household cooking fuel. In this study, we describe the use of low electrical energy input in an anaerobic digestion process using a microbial electrochemical cell (MEC) to promote methane content in biogas at 18, 28, and 37 °C. Although the maximum amount of biogas production was at 37 °C (25 cm3), biogas could be effectively produced at lower temperatures, i.e., 18 (13 cm3) and 28 °C (19 cm3), with an external 2 V power input. The biogas production of 13 cm3 obtained at 18 °C was ~65-fold higher than the biogas produced without an external power supply (0.2 cm3). This was further enhanced by 23% using carbon-nanotubes-treated (CNT) graphite electrodes. This suggests that the MEC can be operated at as low as 18 °C and still produce significant amounts of biogas. The share of CH4 in biogas produced in the controls was 30%, whereas the biogas produced in an MEC had 80% CH4. The MEC effectively reduced COD to 42%, whereas it consumed 98% of reducing sugars. Accordingly, it is a suitable method for waste/manure treatment. Molecular characterization using 16s rRNA sequencing confirmed the presence of methanogenic bacteria, viz., Serratia liquefaciens and Zoballella taiwanensis, in the inoculum used for the fermentation. Consistent with recent studies, we believe that electromethanogenesis will play a significant role in the production of value-added products and improve the management of waste by converting it to energy.

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  • 30.
    Biollaz, S.
    et al.
    PSI.
    Calbry-Muzyka, A.
    PSI.
    Rodriguez, S.
    PSI.
    Sárossy, Z.
    DTU.
    Ravenni, G.
    DTU.
    Fateev, A.
    DTU.
    Seiser, R.
    UCSD.
    Eberhard, M.
    KIT.
    Kolb, T.
    KIT.
    Heikkinen, N.
    VTT.
    Reinikainen, M.
    VTT.
    Brown, R.C.
    Iowa State University, USA.
    Johnston, P.A.
    Iowa State University, USA.
    Nau, P.
    DLR.
    Geigle, K.P.
    DLR.
    Kutne, P.
    DLR.
    Işık-Gülsaç, I.
    TÜBİTAK Mam.
    Aksoy, P.
    TÜBİTAK Mam.
    Çetin, Y.
    TÜBİTAK Mam.
    Sarıoğlan, A.
    TÜBİTAK Mam.
    Tsekos, C.
    Delft University of Technology, Netherlands.
    de Jong, W.
    Delft University of Technology, Netherlands.
    Benedikt, F.
    TU Wien, Austria.
    Hofbauer, H.
    TU Wien, Austria.
    Waldheim, L.
    SFC.
    Engvall, K.
    KTH Royal instute of technology, Sweden.
    Neubauer, Y.
    Technical University of Berlin, Germany.
    Funcia, I.
    CENER.
    Gil, J.
    CENER.
    del Campo, I.
    CENER.
    Wilson, I.
    University of Glasgow, UK.
    Khan, Z.
    University of Glasgow, UK.
    Gall, D.
    University of Gothenburg, Sweden.
    Gómez-Barea, A.
    University of Seville, Spain.
    Schmidt, F.
    Umeå University, Sweden.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Anca-Couce, A.
    Graz University of Technology, Austria.
    von Berg, L.
    Graz University of Technology, Austria.
    Larsson, A.
    GoBiGas.
    Sánchez Hervás, J.M.
    CIEMAT.
    van Egmond, B.F.
    ECN part of TNO.
    Geusebroek, M.
    ECN part of TNO.
    Toonen, A.
    ECN part of TNO.
    Kuipers, J.
    ECN part of TNO.
    Cieplik, M.
    ECN part of TNO.
    Boymans, E.H.
    ECN part of TNO.
    Grootjes, A.J.
    ECN part of TNO.
    Fischer, F.
    TUM.
    Schmid, M.
    University of Stuttgart, Germany.
    Maric, J.
    Chalmers University of Technology, Sweden.
    Defoort, F.
    CEA.
    Ravel, S.
    CEA.
    Thiery, S.
    CEA.
    Balland, M.
    CEA.
    Kienzl, N.
    Bioenergy 2020+.
    Martini, S.
    Bioenergy 2020+.
    Loipersböck, J.
    Bioenergy 2020+.
    Basset, E.
    ENGIE Lab CRIGEN.
    Barba, A.
    ENGIE Lab CRIGEN.
    Willeboer, W.
    RWE-Essent.
    Venderbosch, R.
    BTG.
    Carpenter, D.
    NREL.
    Pinto, F.
    LNEG.
    Barisano, D.
    ENEA.
    Baratieri, M.
    UNIBZ.
    Ballesteros, R.
    UCLM.
    Mourao Vilela, C. (Editor)
    ECN part of TNO.
    Vreugdenhil, B.J. (Editor)
    ECN part of TNO.
    Gas analysis in gasification of biomass and waste: Guideline report: Document 12018Report (Refereed)
    Abstract [en]

    Gasification is generally acknowledged as one of the technologies that will enable the large-scale production of biofuels and chemicals from biomass and waste. One of the main technical challenges associated to the deployment of biomass gasification as a commercial technology is the cleaning and upgrading of the product gas. The contaminants of product gas from biomass/waste gasification include dust, tars, alkali metals, BTX, sulphur-, nitrogen- and chlorine compounds, and heavy metals. Proper measurement of the components and contaminants of the product gas is essential for the monitoring of gasification-based plants (efficiency, product quality, by-products), as well as for the proper design of the downstream gas cleaning train (for example, scrubbers, sorbents, etc.). In practice, a trade-off between reliability, accuracy and cost has to be reached when selecting the proper analysis technique for a specific application. The deployment and implementation of inexpensive yet accurate gas analysis techniques to monitor the fate of gas contaminants might play an important role in the commercialization of biomass and waste gasification processes.

    This special report commissioned by the IEA Bioenergy Task 33 group compiles a representative part of the extensive work developed in the last years by relevant actors in the field of gas analysis applied to(biomass and waste) gasification. The approach of this report has been based on the creation of a team of contributing partners who have supplied material to the report. This networking approach has been complemented with a literature review. The report is composed of a set of 2 documents. Document 1(the present report) describes the available analysis techniques (both commercial and underdevelopment) for the measurement of different compounds of interest present in gasification gas. The objective is to help the reader to properly select the analysis technique most suitable to the target compounds and the intended application. Document 1 also describes some examples of application of gas analysis at commercial-, pilot- and research gasification plants, as well as examples of recent and current joint research activities in the field. The information contained in Document 1 is complemented with a book of factsheets on gas analysis techniques in Document 2, and a collection of video blogs which illustrate some of the analysis techniques described in Documents 1 and 2.

    This guideline report would like to become a platform for the reinforcement of the network of partners working on the development and application of gas analysis, thus fostering collaboration and exchange of knowledge. As such, this report should become a living document which incorporates in future coming progress and developments in the field.

  • 31.
    Biollaz, S.
    et al.
    PSI.
    Calbry-Muzyka, A.
    PSI.
    Rodriguez, S.
    PSI.
    Sárossy, Z.
    DTU.
    Ravenni, G.
    DTU.
    Fateev, A.
    DTU.
    Seiser, R.
    UCSD.
    Eberhard, M.
    KIT.
    Kolb, T.
    KIT.
    Heikkinen, N.
    VTT.
    Reinikainen, M.
    VTT.
    Brown, R.C.
    Iowa State University, USA.
    Johnston, P.A.
    Iowa State University, USA.
    Nau, P.
    DLR.
    Geigle, K.P.
    DLR.
    Kutne, P.
    DLR.
    Işık-Gülsaç, I.
    TÜBİTAK Mam.
    Aksoy, P.
    TÜBİTAK Mam.
    Çetin, Y.
    TÜBİTAK Mam.
    Sarıoğlan, A.
    TÜBİTAK Mam.
    Tsekos, C.
    Delft University of Technology, Netherlands.
    de Jong, W.
    Delft University of Technology, Netherlands.
    Benedikt, F.
    TU Wien, Austria.
    Hofbauer, H.
    TU Wien, Austria.
    Waldheim, L.
    SFC.
    Engvall, K.
    KTH Royal instute of technology, Sweden.
    Neubauer, Y.
    Technical University of Berlin, Germany.
    Funcia, I.
    CENER.
    Gil, J.
    CENER.
    del Campo, I.
    CENER.
    Wilson, I.
    University of Glasgow, UK.
    Khan, Z.
    University of Glasgow, UK.
    Gall, D.
    Gothenburg University, Sweden.
    Gómez-Barea, A.
    University of Seville, Spain.
    Schmidt, F.
    Umeå University, Sweden.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Anca-Couce, A.
    Graz University of Technology, Austria.
    von Berg, L.
    Graz University of Technology, Austria.
    Larsson, A.
    GoBiGas.
    Sánchez Hervás, J.M.
    CIEMAT.
    van Egmond, B.F.
    ECN part of TNO.
    Geusebroek, M.
    ECN part of TNO.
    Toonen, A.
    ECN part of TNO.
    Kuipers, J.
    ECN part of TNO.
    Cieplik, M.
    ECN part of TNO.
    Boymans, E.H.
    ECN part of TNO.
    Grootjes, A.J.
    ECN part of TNO.
    Fischer, F.
    TUM.
    Schmid, M.
    University of Stuttgart, Germany.
    Maric, J.
    Chalmers University of Technology, Sweden.
    Defoort, F.
    CEA.
    Ravel, S.
    CEA.
    Thiery, S.
    CEA.
    Balland, M.
    CEA.
    Kienzl, N.
    Bioenergy 2020+.
    Martini, S.
    Bioenergy 2020+.
    Loipersböck, J.
    Bioenergy 2020+.
    Basset, E.
    ENGIE Lab CRIGEN.
    Barba, A.
    ENGIE Lab CRIGEN.
    Willeboer, W.
    RWE-Essent.
    Venderbosch, R.
    BTG.
    Carpenter, D.
    NREL.
    Pinto, F.
    LNEG.
    Barisano, D.
    ENEA.
    Baratieri, M.
    UNIBZ.
    Ballesteros, R.
    UCLM.
    Mourao Vilela, C. (Editor)
    ECN part of TNO.
    Vreugdenhil, B.J. (Editor)
    ECN part of TNO.
    Gas analysis in gasification of biomass and waste: Guideline report: Document 2 - Factsheets on gas analysis techniques2018Report (Refereed)
    Abstract [en]

    Gasification is generally acknowledged as one of the technologies that will enable the large-scale production of biofuels and chemicals from biomass and waste. One of the main technical challenges associated to the deployment of biomass gasification as a commercial technology is the cleaning and upgrading of the product gas. The contaminants of product gas from biomass/waste gasification include dust, tars, alkali metals, BTX, sulphur-, nitrogen- and chlorine compounds, and heavy metals. Proper measurement of the components and contaminants of the product gas is essential for the monitoring of gasification-based plants (efficiency, product quality, by-products), as well as for the proper design of the downstream gas cleaning train (for example, scrubbers, sorbents, etc.). The deployment and implementation of inexpensive yet accurate gas analysis techniques to monitor the fate of gas contaminants might play an important role in the commercialization of biomass and waste gasification processes.

    This special report commissioned by the IEA Bioenergy Task 33 group compiles a representative part of the extensive work developed in the last years by relevant actors in the field of gas analysis applied to (biomass and waste) gasification. The approach of this report has been based on the creation of a team of contributing partners who have supplied material to the report. This networking approach has been complemented with a literature review. This guideline report would like to become a platform for the reinforcement of the network of partners working on the development and application of gas analysis, thus fostering collaboration and exchange of knowledge. As such, this report should become a living document which incorporates in future coming progress and developments in the field.

  • 32.
    Björn (Fredriksson), Annika
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ziels, Ryan
    Linköping University, Biogas Research Center. Department of Civil Engineering, University of British Columbia, Columbia, Canada.
    Karl, Gustafsson
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Svensson, Bo H
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Anna, Karlsson
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Stockholm, Sweden.
    Feasibility of OFMSW co-digestion with sewage sludge for increasing biogas production at wastewater treatment plants2017In: Euro-Mediterranean Journal for Environmental Integration, ISSN 2365-6433, Vol. 2, no 21Article in journal (Refereed)
    Abstract [en]

    Sweden has the ambition to increase its annual biogas production from the current level of 1.9 to 15 TWh by 2030. The unused capacity of existing anaerobic digesters at wastewater treatment plants is among the options to accomplish this goal. This study investigated the feasibility of utilizing the organic fraction of municipal solid waste (OFMSW) as a co-substrate, with primary and waste-activated sewage sludge (PWASS) for production of biogas, corresponding to 3:1 ratio on volatile solid (VS) basis. The results demonstrated that co-digestion of OFMSW with PWASS at an organic loading rate of 5 gVS l−1 day−1 has the potential to increase the biogas production approximately four times. The daily biogas production increased from 1.0 ± 0.1 to 3.8 ± 0.3 l biogasl−1 day−1, corresponding to a specific methane production of 420 ± 30 Nml methane gVS−1 during the laboratory experiment. Co-digestion of OFMSW with PWASS showed a 50:50 distribution of hydrogenotrophic and aceticlastic methanogens in the digester and enhanced the turnover kinetics of intermediate products (acetate, propionate, and oleate). Practical limitations potentially include the need for sludge dewatering to maintain a sufficient hydraulic retention time (17 days in this study), as well as additional energy consumption for mixing due to an increased sludge apparent viscosity (from 1.8 ± 0.1 to 45 ± 4.8 mPa*s in this study) at elevated OFMSW-loading rates.

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  • 33.
    Bozaghian Bäckman, Marjan
    et al.
    Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, Ume.
    Strandberg, Anna
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    De La Fuente, Teresa
    Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, Umeå, Sweden.
    Karjalainen, Mikko
    Luke Natural Resources Institute Finland, Kokkola, Finland.
    Skoglund, Nils
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Thyrel, Mikael
    Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, Umeå, Sweden.
    Bergström, Dan
    Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, Umeå, Sweden.
    Larsson, Sylvia H.
    Swedish University of Agricultural Sciences, Department of Forest Biomaterials and Technology, Umeå, Sweden.
    Does mechanical screening improve fuel properties?: Effects of mechanical screening of stored logging residue chips on ash chemistry and other parameters relevant for combustion2019Conference paper (Refereed)
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    poster
  • 34.
    Brandberg, Martin
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jönsson, Erik
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Spillvärme i Kronobergs län: En kartläggning med enkätundersökning2022Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den här rapporten kartlägger den energimängd i form av spillvärme som tillförs fjärrvärmenäten i Kronobergs län samt undersöker spillvärmepotentialen från företag i Kronobergs län. Resultat för nuvarande tillförsel av spillvärme till fjärrvärmenäten i Kronobergs län summerades till 4–5 GWh per år. För enkätundersökningen kontaktades 124 företag och av dessa uppgav 55 att det förekom spillvärme i processen. Det finns enligt enkätundersökningen sju företag inom Kronobergs län vars spillvärme håller en temperatur över 80 °C och som ej nyttjas för fjärrvärmeproduktion i dagsläget. Därmed bör den vara tillräckligt hög för att kunna levereras till framledningen i fjärrvärmenätet. Endast nio företag kunde svara på hur mycket spillvärme som uppkom från verksamheten, denna summerades till ca 25 GWh/år, dock angav samtliga dessa att den i varierande grad att nyttjades internt och temperaturen på spillvärmen var i åtta fall i intervallet 25–60 °C. För att avgöra om det är möjligt att utöka tillförseln av spillvärme till fjärrvärmenäten i Kronobergs län så måste dock förutsättningarna utredas mer utförligt hos respektive företag där potential finnes.

  • 35.
    Brandin, Jan
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Usage of Biofuels in Sweden2013In: CSR-2 Catalyst for renewable sources: Fuel, Energy, Chemicals Book of Abstracts / [ed] Vadim Yakovlev, Boreskov Institute of Catalysis, Novosibrisk, Russia: Boreskov Institute of Catalysis , 2013, p. 5-7Conference paper (Refereed)
    Abstract [en]

    In Sweden, biofuels have come into substantial use, in an extent that are claimed to be bigger than use of fossil oil. One driving force for this have been the CO2-tax that was introduced in 1991 (1). According to SVEBIO:s calculations (2) based on the Swedish Energy Agency´s prognosis, the total energy consumption in Sweden 2012 was 404 TWh. If the figure is broken down on the different energy sources (figure 1) one can see that the consumption roughly distribute in three different, equally sized, blocks, Biofuels, fossil fuels and water & nuclear power. The major use of the fossil fuels is for transport and the water & nuclear power is used as electric power. The main use of the biofuels is for heating in the industrial sector and as district heating. In 2009 the consumption from those two segments was 85 TWh, and 10 TWh of bio power was co-produced giving an average biomass to electricity efficiency of 12%. This indicates a substantial conversion potential from hot water production to combined heat and power (CHP) production. in Sweden 2013 broken down on the different energy sources. In 2006 the pulp, paper and sawmill industry accounted for 95% of the bio energy consumption in the industrial sector, and the major biofuel consumed was black liquor (5). However, the pulp and paper industries also produced the black liquor in their own processes. The major energy source (58%) for district heating during 2006 was woody biomass (chips, pellets etc.) followed by waste (24%), peat (6%) and others (12%) (5). The use of peat has probably decreased since 2006 since peat is no longer regarded as a renewable energy source. While the use of biofuel for heating purpose is well developed and the bio-power is expected to grow, the use in the transport sector is small, 9 TWh or 7% in 2011. The main consumption there is due to the mandatory addition (5%) of ethanol to gasoline and FAME to diesel (6). The Swedish authorities have announced plans to increase the renewable content to 7.5 % in 2015 on the way to fulfill the EU’s goal of 10 % renewable transportation fuels in 2020. However the new proposed fuel directive in EU says that a maximum of 5% renewable fuel may be produced from food sources like sugars and vegetable oils. Another bothersome fact is that, in principle, all rape seed oil produced in Sweden is consumed (95-97%) in the food sector, and consequently all FAME used (in principle) in Sweden is imported as FAME, rape seed oil or seed (6). In Sweden a new source of biodiesel have emerged, tall oil diesel. Tall oil is extracted from black liquor and refined into a diesel fraction (not FAME) and can be mixed into fossil diesel, i.e. Preem Evolution diesel. The SUNPINE plant in Piteå have a capacity of 100 000 metric tons of tall oil diesel per annum, while the total potential in all of Sweden is claimed to be 200 000 tons (7). 100 000 tons of tall oil corresponds to 1% of the total diesel consumption in Sweden. in Sweden for 2010 and a prognosis for 2014. (6). Accordingly, the profoundest task is to decrease the fossil fuel dependency in the transport sector, and clearly, the first generation biofuels can´t do this on its own. Biogas is a fuel gas with high methane content that can be used in a similar way to natural gas; for instance for cooking, heating and as transportation fuel. Today biogas is produced by fermentation of waste (municipal waste, sludge, manure), but can be produced by gasification of biomass, for instance from forest residues such as branches and rots (GROT in Swedish). To get high efficiency in the production, the lower hydrocarbons, mainly methane, in the producer gas, should not be converted into synthesis gas. Instead a synthesis gas with high methane content is sought. This limits the drainage of chemically bonded energy, due to the exothermic reaction in the synthesis step (so called methanisation). In 2011 0.7 TWh of biogas was produced in Sweden by fermentation of waste (6) and there were no production by gasification, at least not of economic importance. The potential seems to be large, though. In 2008 the total potential for biogas production, in Sweden, from waste by fermentation and gasification was estimated to 70 TWh (10 TWh fermentation and 60 TWh gasification) (8). This figure includes only different types of waste and no dedicated agricultural crops or dedicated forest harvest. Activities in the biogas sector, by gasification, in Sweden are the Göteborgs energi´s Gobigas project in Gothenburg and Eon´s Bio2G-project, now pending, in south of Sweden. If the producer gas is cleaned and upgraded into synthesis gas also other fuels could be produced. In Sweden methanol and DME productions are planned for in the Värmlands metanol-project and at Chemrecs DME production plant in Piteå.

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  • 36.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Hulteberg, Christian
    Lunds Tekniska Högskola .
    Leveau, Andreas
    Biofuel-Solutions AB.
    Selective Catalysts for Glycerol Dehydration2013In: CRS-2, Catalysis for Renewable Sources: Fuel,Energy,ChemicalsBook of Abstracts / [ed] Vadim Yakovlev, Boreskov Institute of Catalysis, Novosibirsk, Russia: Boreskov Institute of Catalysis , 2013, p. 17-18Conference paper (Refereed)
    Abstract [en]

     There has been an increased interest over the last decade for replacing fossil based feedstock’s with renewable ones. There are several such feedstock’s that are currently being investigated such as cellulose, lignin, hemicellulose, triglycerides etc. However, when trying to perform selective reactions an as homogeneous feedstock as possible is preferable. One such feedstock example is glycerol, a side-product from biofuels production, which is a tri-alcohol and thus has much flexibility for reactions, e.g. dehydration, hydrogenation, addition reactions etc. Glycerol in itself is a good starting point for fine chemicals production being non-toxic and available in rather large quantities [1-2]. A key reaction for glycerol valorisation is the dehydration of glycerol to form acrolein, an unsaturated C3 aldehyde, which may be used for producing acrylic acid, acrylonitrile and other important chemcial products. It has recently been shown that pore-condensation of glycerol is an issue under industrial like conditions, leading to liquid-phase reactions and speeding up the catalyst activity and selectivity loss [3]. To address this issue, modified catalyst materials have been prepared where the relevant micro and meso pores have been removed by thermal sintering; calculations have shown that pores below 45 Å may be subject to pore condensation. The catalyst starting material was a 10% WO3 by weight supported on ZrO2 in the form of beads 1–2 mm and it was thermally treated at 400°C, 500°C, 600°C, 700°C, 700°C, 800°C, 850°C, 900°C and 1000°C for 2 hours. The catalysts were characterised using nitrogen adsorption, mercury intrusion porosimetry (MIP), Raman spectroscopy and ammonia temperature programmed desorption. The thermal sintered catalysts show first of all a decreasing BET surface area with sintering commencing between 700°C and 800°C when it decreases from the initial 71 m2/g to 62 m2/g and at 1000°C there is a mere 5 m2/g of surface area left. During sintering, the micro and meso-porosity is reduced as evidenced by MIP and depicted in figure 1. As may be seen in the figure, sintering decrease the amount of pores below and around 100 Å is reduced at a sintering temperature of 800°C and above. The most suitable catalyst based on the MIP appears to be the one sintered at 850°C which is further strengthened by the Raman analysis. There is a clear shift in the tungsten structure from monoclinic to triclinic between 850°C and 900°C and it is believed that the monoclinic phase is important for activity and selectivity. Further, the heat treatment shows that there is an increase in catalyst acidity measured as mmol NH3/(m2/g) but a decrease in the acid strength as evidenced by a decrease in the desorption peak maximum temperature.

     

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  • 37.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Odenbrand, Ingemar
    Lund University .
    Poisoning of SCR Catalysts used in Municipal Waste Incineration Applications2017In: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 60, no 17-18, p. 1306-1316Article in journal (Refereed)
    Abstract [en]

    A commercial vanadia, tungsta on titania SCRcatalyst was poisoned in a side stream in a waste incinerationplant. The effect of especially alkali metal poisoning was observed resulting in a decreased activity at long times of exposure. The deactivation after 2311 h was 36% whilet he decrease in surface area was only 7.6%. Thus the major cause for deactivation was a chemical blocking of acidic sites by alkali metals. The activation–deactivation model showed excellent agreement with experimental data. The model suggests that the original adsorption sites, from the preparation of the catalyst, are rapidly deactivated but are replaced by a new population of adsorption sites due to activation of the catalyst surface by sulphur compounds (SO2, SO3) in the flue gas.

  • 38.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Tunér, Martin
    Lunds Tekniska Högskola.
    Odenbrand, Ingemar
    Lunds Tekniska Högskola.
    Small Scale Gasifiction: Gas Engine CHP for Biofuels2011Report (Other academic)
    Abstract [en]

    In a joint project, Linnaeus University in Växjö (LNU) and the Faculty of Engineering at Lund University (LTH) were commissioned by the Swedish Energy Agency to make an inventory of the techniques and systems for small scale gasifier-gas engine combined heat and power (CHP) production and to evaluate the technology. Small scale is defined here as plants up to 10 MWth, and the fuel used in the gasifier is some kind of biofuel, usually woody biofuel in the form of chips, pellets, or sawdust. The study is presented in this report.

    The report has been compiled by searching the literature, participating in seminars, visiting plants, interviewing contact people, and following up contacts by e-mail and phone.

    The first, descriptive part of the report, examines the state-of-the-art technology for gasification, gas cleaning, and gas engines. The second part presents case studies of the selected plants:

    • Meva Innovation’s VIPP-VORTEX CHP plant
    • DTU’s VIKING CHP plant
    • Güssing bio-power station
    • Harboøre CHP plant
    • Skive CHP plant

    The case studies examine the features of the plants and the included unit operations, the kinds of fuels used and the net electricity and overall efficiencies obtained. The investment and operating costs are presented when available as are figures on plant availability. In addition we survey the international situation, mainly covering developing countries.

    Generally, the technology is sufficiently mature for commercialization, though some unit operations, for example catalytic tar reforming, still needs further development. Further development and optimization will probably streamline the performance of the various plants so that their biofuel-to-electricity efficiency reaches 30-40 % and overall performance efficiency in the range of 90 %.

    The Harboøre, Skive, and Güssing plant types are considered appropriate for municipal CHP systems, while the Viking and VIPP-VORTEX plants are smaller and considered appropriate for replacing hot water plants in district heating network. The Danish Technical University (DTU) Biomass Gasification Group and Meva International have identified a potentially large market in the developing countries of Asia.

    Areas for suggested further research and development include:

    • Gas      cleaning/upgrading
    • Utilization      of produced heat
    • System      integration/optimization
    • Small scale      oxygen production
    • Gas engine      developments
    Download full text (pdf)
    Gas Engine CHP for Biofuels.pdf
  • 39.
    Broström, Markus
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Holmgren, Per
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ash fractionation and slag formation during entrained flow biomass gasification2018Conference paper (Other academic)
  • 40. Buss, Wolfram
    et al.
    Jansson, Stina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Wurzer, Christian
    Masek, Ondrej
    Synergies between BECCS and Biochar-Maximizing Carbon Sequestration Potential by Recycling Wood Ash2019In: ACS Sustainable Chemistry and Engineering, E-ISSN 2168-0485, Vol. 7, no 4, p. 4204-4209Article in journal (Refereed)
    Abstract [en]

    Bioenergy carbon capture and storage (BECCS) and biochar are key carbon-negative technologies. In this study, synergies between these technologies were explored by using ash from wood combustion, a byproduct from BECCS, as an additive (0, 5, 10, 20, and 50 wt %) in biochar production (wood pyrolysis at 450 degrees C). The addition of wood ash catalyzed biochar formation and increased the yield of fixed carbon (FC) (per dry, ash-free feedstock), i.e., the sequestrable carbon per spruce wood input. At the highest ash addition (50%), 45% less wood was needed to yield the same amount of FC. Since the land area available for growing biomass is becoming scarcer, our approach significantly increases biochar's potential to sequester carbon. However, increasing the feedstock ash content results in less feedstock carbon available for conversion into FC. Consequently, the yield of FC per pyrolysis run (based on dry feedstock) in the 50% ash-amended material was lower than in the control. An economic analysis showed that the 20% ash-amended biochar brings the biggest cost savings over the control with a 15% decrease in CO2-abatement costs. Biochar-ash composites increase the carbon sequestration potential of biochar significantly, reduce the CO2-abatement costs, and recycle nutrients which can result in increased plant growth in turn and more biomass for BECCS, bringing synergies for BECCS and biochar deployment.

  • 41.
    Bäckebo, Markus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    The influence of particle size distribution on bio-coal gasification rate as related to packed beds of particles2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis is a part of a collaboration between Höganäs AB and Luleå University of Technology, aiming at replacing fossil process coal with bio-coal in their sponge iron process. The difference in gasification reactivity, i.e. reaction rate, between fossil coals and bio-coals is the major challenge in the endeavor to decrease the climate impact of the existing process. The goal of this thesis is to develop a model of reaction rate for bio-coals in relation to particle size distribution. Different particle size distributions were combined and tested to see how that affects the effective reaction rate.

    Within the scope of this work, gasification reactivities of different materials, including coal, cokes, and bio-coals, were determined. Three bio-coals were selected to study the effect of particle size distribution on reactivity. Kinetic parameters were determined by using thermogravimetric analysis in the temperature range of 770-850 °C while varying CO2 partial pressure between 0.1-0.4 atm. The effect of particle size on the reaction rate was investigated by using particles with diameter between 0.18 and 6.3 mm. The effect of particle size distribution on the reactivity of bio-coal in a packed bed was carried out in a macro thermogravimetric reactor with a constant bed volume of 6.5 cm3 at 980 °C and 40% (vol.) of CO2.

    The experimental investigation in three different rate-limiting steps was done for one bio-coal sample, i.e. Cortus Bark bio-coal. The activation energy of the bio-coal was 187 kJ mol-1, and the reaction order was 0.365. For the internal diffusion control regime, an increase in particle size resulted in low reaction rate. The effective diffusivity calculated from the Thiele modulus model was 1.41*10-5 m2 s-1. For the external diffusion control regime, an increase in particle size increased the reaction rate up to a certain point where it plateaued at >1 mm. By choosing two discrete particle size distributions, where a smaller average distribution can fit into a larger average distribution the reaction rate was lowered by 30% compared to only using a single narrow particle size distribution. This solution decreased the difference of apparent reaction rate in a packed bed between the bio-coal and anthracite from 6.5 times to 4.5 times.

    At the moment the model is not generalized for all bio-coals. However, the developed methodology can be routinely applied to assess the different bio-coal samples. One possible error can be that pyrolysis influences the gasification rate for bio-coal that is pyrolyzed below the temperature of the gasification test. There is a clear correlation between particle size distributions, bulk density, and apparent reactivity. By mixing two distributions the reaction rate of Cortus Bark was reduced from 6.5 times the reaction rate of anthracite to 4.5.

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    fulltext
  • 42.
    Böhlenius, Henrik
    et al.
    Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, SE-234 56 Alnarp, Sweden.
    Öhman, Marcus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Granberg, Fredrik
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Persson, Per-Ove
    Persson f.N.B. AB, SE-54197, Lerdala, Sweden.
    Biomass production and fuel characteristics from long rotation poplar plantations2023In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 178, article id 106940Article in journal (Refereed)
    Abstract [en]

    One of the key elements in this transition is the securing of a large supply of sustainable biomass. In this study, the feedstock potential of long rotation poplar plantations (12–30 years with diameter of 15 of 30 cm) was determined and the properties of poplar biomass fuel were analyzed with the aim of using thermochemical conversion methods to produce biofuel. Our results demonstrate that Sweden has great potential for producing biofuels from long rotation poplar plantations, with a total of 1.8 million hectares (ha) consisting of arable (0.5 million ha) and forested arable land (1.3 million ha). Based on available land and biomass production potential, our results indicate that 10 million Mg DW could be produced annually. Regions in mid/southern Sweden have the largest potential (larger areas and higher biomass production. Our results further suggest that poplar biomass from these plantations has fuel characteristics similar to forest fuels from other conifer tree species, making the biomass suitable as feedstock for biofuel production based on thermochemical conversion methods. If 25% of the available land were used, 7.6 TWh methanol biofuels could be produced annually from 16 biofuel plants, using 160,000 Mg DW yr−1, primarily located in the southern part of Sweden. Two counties (Skåne and Västra Götaland) would be able to support their biofuel plants using poplar plantations as feedstock. Stable biofuel production in the other counties would depend on collaborating with neighboring counties.

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    fulltext
  • 43. Campisi, T.
    et al.
    Tesoriere, G.
    Skoufas, Anastasios
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport planning.
    Zeglis, D.
    Andronis, C.
    Basbas, S.
    Perceived Pedestrian Level of Service: The case of Thessaloniki, Greece2022In: Transportation Research Procedia, Elsevier BV , 2022, p. 124-131Conference paper (Refereed)
    Abstract [en]

    Level of Service (LOS) is one of the most crucial components for the assessment of pedestrian facilities by mainly concerning the effective width as well as pedestrians’ flows. However, current research reveals that qualitative characteristics can also contribute to LOS estimation as perceived by pedestrians. Specifically, socio-demographic characteristics (i.e., age, gender) as well as characteristics related with perceived comfort and safety can be related with perceived LOS. A Revealed Preference (RP) face to face questionnaire-based survey (including 301 interviewees) was realized during October 2019 at a central pedestrian facility in the city of Thessaloniki, Greece. RP questionnaire survey assisted in gaining valuable knowledge concerning the factors that mainly affect pedestrians’ perceived LOS across the pedestrian facility. The examined pedestrian facility is one of the most important in Thessaloniki since it facilitates high pedestrian flows within the city center daily. The present survey considered pedestrians’ general mobility characteristics such as walking frequency along the facility and trip purpose. Additionally, the evaluation of the greater facility’ area in terms of land use attractiveness, comfort, personal and road safety, public transport, parking conditions and traffic delays, accessibility, pedestrians and bicycles were concerned as well. Ordinal regression was the main tool for the development of the ordinal regression model, and therefore, for the conclusions’ drawing of the present research. The findings regarding perceived LOS can pave the way towards the design of sustainable policy concerning pedestrian facilities as well as the encouragement of active transport in urban areas.

  • 44.
    Cao, Wenhan
    et al.
    University of Strathclyde, UK.
    Li, Jun
    University of Strathclyde, UK.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Zhang, Xiaolei
    University of Strathclyde, UK.
    Release of potassium in association with structural evolution during biomass combustion2021In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 287, p. 1-9, article id 119524Article in journal (Refereed)
    Abstract [en]

    A mechanistic understanding of potassium release is essential to mitigate the potassium-induced ash problems during biomass combustion. This work studies the effects of operational condition on the potassium release and transition during the combustion of wheat straw, and elucidate the release potential of potassium associated with the structural change of biomass particles. The combustion tests were carried out in a laboratory-scale reactor, working in a wide range of temperatures and heating rates. It was found that the combustion of biomass sample at a temperature up to 1000 °C results in a release of over 60% of its initial potassium content. Raising the heating rate from 8 °C/min to 25 °C/min could lead to an additional release of up to 20% of the initial amount of potassium. A three-stage potassium release mechanism has been concluded from this work: the initial-step release stage (below 400 °C), the holding stage (400–700 °C) and the second-step release stage (above 700 °C). Comprehensive morphology analysis with elemental (i.e. K, S, O, Si) distribution was carried out; the results further confirmed that potassium is likely to exist inside the stem-like tunnel of biomass particles, mainly in forms of inorganic salts. During the heating-up process, the breakdown and collapse of biomass particle structure could expose the internally located potassium and thus accelerate the release of potassium and the transform of its existing forms. Lastly, a detailed temperature-dependent release mechanism of potassium was proposed, which could be used as the guidance to mitigate the release of detrimental potassium compounds by optimising the combustion process.

  • 45. Capablo, Joaquin
    et al.
    Arendt Jensen, Peter
    Hougaard Pedersen, Kim
    Hjuler, Klaus
    Nikolaisen, Lars
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Frandsen, Flemming
    Ash properties of alternative biomass2009In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 23, p. 1965-1976Article in journal (Refereed)
    Abstract [en]

    The ash behavior during suspension firing of 12 alternative solid biofuels, such as pectin waste, mash from a beer brewery, or waste from cigarette production have been studied and compared to wood and straw ash behavior. Laboratory suspension firing tests were performed on an entrained flow reactor and a swirl burner test rig, with special emphasis on the formation of fly ash and ash deposit. Thermodynamic equilibrium calculations were performed to support the interpretation of the experiments. To generalize the results of the combustion tests, the fuels are classified according to fuel ash analysis into three main groups depending upon their ash content of silica, alkali metal, and calcium and magnesium. To further detail the biomass classification, the relative molar ratio of Cl, S, and P to alkali were included. The study has led to knowledge on biomass fuel ash composition influence on ash transformation, ash deposit flux, and deposit chlorine content when biomass fuels are applied for suspension combustion.

  • 46.
    Carraro, Giacomo
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Solutions Research Center.
    Tonderski, Karin
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering. Linköping University, Biogas Solutions Research Center.
    Enrich Prast, Alex
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Solutions Research Center. Institute of Marine Science, Federal University of Sao Paolo, Santos, Brazil.
    Solid-liquid separation of digestate from biogas plants: A systematic review of the techniques’ performance2024In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 356, article id 120585Article, review/survey (Refereed)
    Abstract [en]

    Digestate processing is a strategy to improve the management of digestate from biogas plants. Solid-liquid separation is usually the primary step and can be followed by advanced treatments of the fractions. The knowledge about the performance of the separators and the quality of the fractions is scattered because of many available techniques and large variability in digestate characteristics. We performed a systematic review and found 175 observations of full-scale solid-liquid separation of digestate. We identified 4 separator groups, 4 digestate classes based on substrate, and distinguished whether chemical conditioners were used. We confirmed the hypothesis that the dominant substrate can affect the efficiency of the digestate separation. Furthermore, the results showed that centrifuges separated significantly more dry matter and total P than screw presses. Use of chemical conditioners in combination with a centrifuge lowered the dry matter concentration in the liquid fraction by 30%. Screw presses consumed 4.5 times less energy than centrifuges and delivered 3.3 tonne ammonium N in the liquid fraction and 0.3 tonne total P in the solid fraction using 1 MWh. The results can provide data for systems analyses of biogas solutions and can support practitioners when choosing among full-scale separator techniques depending on the digestate type. In a broader perspective, this work contributes to the continuous improvement of biogas plants operations and to their role as nutrients recovery sites.

  • 47.
    Carvalho, Ricardo L.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Centre of Environment and Marine Studies, University of Aveiro, Aveiro, Portugal.
    Yadav, Pooja
    Dept. of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Lindgren, Robert
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    García-López, Naxto
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nyberg, Gert
    Dept. of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Diaz-Chavez, Rocio
    Stockholm Environment Institute, Africa Centre, c/o World Agroforestry Centre, P.O. Box 30677, Nairobi, Kenya.
    Upadhyayula, Venkata Krishna Kumar
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Athanassiadis, Dimitris
    Dept. of Forest Biomaterials and Technology, Swedish University of Agricultural Sciences, Umeå, Sweden.
    Bioenergy strategies to address deforestation and household air pollution in western Kenya2019In: European Biomass Conference and Exhibition Proceedings, ETA-Florence Renewable Energies , 2019, p. 1536-1542Conference paper (Refereed)
    Abstract [en]

    Over 640 million people in Africa are expected to rely on solid-fuels for cooking by 2040. In Western Kenya, cooking inefficiently persists as a major cause of burden disease due to household air pollution. The Long-Range Energy Alternatives Planning (LEAP) system and the Life-Cycle Assessment tool Simapro 8.5 were applied for analyzing biomass strategies for the region. The calculation of the residential energy consumption and emissions was based on scientific reviews and original data from experimental studies. The research shows the effect of four biomass strategies on the reduction of wood fuel use and short-lived climate pollutant emissions. A Business As Usual scenario (BAU) considered the trends in energy use until 2035. Transition scenarios to Improved Cookstoves (ICS), Pellet-fired Gasifier Stoves (PGS) and Biogas Stoves (BGS) considered the transition to wood-logs, biomass pellets and biogas, respectively. An Integrated (INT) scenario evaluated a mix of the ICS, PGS and BGS. The study shows that, energy use will increase by 8% (BGS), 20% (INT), 26% (PGS), 42% (ICS) and 56% (BAU). The BGS has the lowest impact on global warming, particle formation, terrestrial acidification, fossil resource scarcity, water consumption, as well as on eutrophication followed by the PGS and INT.

  • 48.
    Carvalho, Ricardo Luís
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Centre for Environmental and Marine Studies, Department of Environment and Planning, University of Aveiro, Aveiro, Portugal.
    Yadav, Pooja
    García-López, Naxto
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Lindgren, Robert
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nyberg, Gert
    Diaz-Chavez, Rocio
    Upadhyayula, Venkata Krishna Kumar
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Athanassiadis, Dimitris
    Environmental Sustainability of Bioenergy Strategies in Western Kenya to Address Household Air Pollution2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 3, article id 719Article in journal (Refereed)
    Abstract [en]

    Over 640 million people in Africa are expected to rely on solid-fuels for cooking by 2040. In Western Kenya, cooking inefficiently persists as a major cause of burden of disease due to household air pollution. Efficient biomass cooking is a local-based renewable energy solution to address this issue. The Life-Cycle Assessment tool Simapro 8.5 is applied for analyzing the environmental impact of four biomass cooking strategies for the Kisumu County, with analysis based on a previous energy modelling study, and literature and background data from the Ecoinvent and Agrifootprint databases applied to the region. A Business-As-Usual scenario (BAU) considers the trends in energy use until 2035. Transition scenarios to Improved Cookstoves (ICS), Pellet-fired Gasifier Stoves (PGS) and Biogas Stoves (BGS) consider the transition to wood-logs, biomass pellets and biogas, respectively. An Integrated (INT) scenario evaluates a mix of the ICS, PGS and BGS. In the BGS, the available biomass waste is sufficient to be upcycled and fulfill cooking demands by 2035. This scenario has the lowest impact on all impact categories analyzed followed by the PGS and INT. Further work should address a detailed socio-economic analysis of the analyzed scenarios.

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    fulltext
  • 49.
    Casimir, Justin
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Gunnarsson, Carina
    RISE Research Institutes of Sweden, Bioeconomy and Health, Agriculture and Food.
    Farmers current practices, and their opinion on supplying straw for production of second-generation biofuels in Sweden2020Report (Other academic)
    Abstract [en]

    This report presents results from the EU project AGROinLOG (Grant Agreement 727921) and especially focuses on the results from a survey looking at the current practices with straw use in Sweden as well as the farmer’s opinion on supplying straw for the production of second-generation biofuel. The survey was developed as a collaboration between LRF (Federation of Swedish farmers) RISE and Lantmännen.The reader can first read about the context within which the survey was developed and analysed. The questions and the methodology are then presented. The main part of the report presents the questionnaire results before drawing conclusions in line with the project’s objectives.The survey shows that about 60% of the straw from farmers participating in the survey, remains in the field while 40% is harvested mostly for animal production. The county of Skåne, the “ÖSÖ” region (Östergötland, Södermanland, and Örebro counties), the region including Uppsala, Stockholm and Västmanland counties, and the county of Västra Götaland have the largest potential for collection of straw for industrial processes in Sweden. However, farmers from these regions are the most concerned about the decrease of soil quality due to straw removal. The current common practices for straw handling in Sweden, including baling, collection, transport, storage and sale, are highlighted.Some interesting conclusions are drawn concerning the logistics needed for the handling of straw for the biobased industry. Moreover, the answers from the survey give some insights concerning a potential “straw contract” between Lantmännen and the farmers. The report also highlights the aspects to be further researched.More information concerning the Swedish contribution to the AGROinLOG project can be found in the public report AGROinLOG (2020a).

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    fulltext
  • 50.
    Chacón-Navarrete, Helena
    et al.
    Department of Agricultural Chemistry, Edaphology and Microbiology, Agrifood Campus of International Excellence ceiA3, University of Cordoba, Cordoba, Spain.
    Martin, Carlos
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Moreno-García, Jaime
    Department of Agricultural Chemistry, Edaphology and Microbiology, Agrifood Campus of International Excellence ceiA3, University of Cordoba, Cordoba, Spain.
    Yeast immobilization systems for second-generation ethanol production: actual trends and future perspectives2021In: Biofuels, Bioproducts and Biorefining, ISSN 1932-104X, E-ISSN 1932-1031, Vol. 15, no 5, p. 1549-1565Article, review/survey (Refereed)
    Abstract [en]

    Yeast immobilization with low-cost carrier materials is a suitable strategy to optimize the fermentation of lignocellulosic hydrolysates for the production of second-generation (2G) ethanol. It is defined as the physical confinement of intact cells to a certain region of space (the carrier) with the preservation of their biological activity. This technological approach facilitates promising strategies for second-generation bioethanol production due to the enhancement of the fermentation performance that is expected to be achieved. Using immobilized cells, the resistance to inhibitors contained in the hydrolysates and the co-utilization of sugars are improved, along with facilitating separation operations and the reuse of yeast in new production cycles. Until now, the most common immobilization technology used calcium alginate as a yeast carrier but other supports such as biochar or multispecies biofilm membranes have emerged as interesting alternatives. This review compiles updated information about cell carriers and yeast-cell requirements for immobilization, and the benefits and drawbacks of different immobilization systems for second-generation bioethanol production are investigated and compared.

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