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  • 1.
    Abedinifar, S.
    et al.
    Department of Chemical Engineering, Isfahan University of Technology.
    Karimi, K
    Department of Chemical Engineering, Isfahan University of Technology.
    Khanahmadi, M.
    Isfahan Agriculture and Natural Resources Research Centre.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Ethanol production by Mucor indicus and Rhizopus oryzae from rice straw by separate hydrolysis and fermentation2009In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 33, no 5, p. 828-833Article in journal (Refereed)
    Abstract [en]

    Rice straw was successfully converted to ethanol by separate enzymatic hydrolysis and fermentation by Mucor indicus, Rhizopus oryzae, and Saccharomyces cerevisiae. The hydrolysis temperature and pH of commercial cellulase and β-glucosidase enzymes were first investigated and their best performance obtained at 45 °C and pH 5.0. The pretreatment of the straw with dilute-acid hydrolysis resulted in 0.72 g g-1 sugar yield during 48 h enzymatic hydrolysis, which was higher than steam-pretreated (0.60 g g-1) and untreated straw (0.46 g g-1). Furthermore, increasing the concentration of the dilute-acid pretreated straw from 20 to 50 and 100 g L-1 resulted in 13% and 16% lower sugar yield, respectively. Anaerobic cultivation of the hydrolyzates with M. indicus resulted in 0.36-0.43 g g-1 ethanol, 0.11-0.17 g g-1 biomass, and 0.04-0.06 g g-1 glycerol, which is comparable with the corresponding yields by S. cerevisiae (0.37-0.45 g g-1 ethanol, 0.04-0.10 g g-1 biomass and 0.05-0.07 glycerol). These two fungi produced no other major metabolite from the straw and completed the cultivation in less than 25 h. However, R. oryzae produced lactic acid as the major by-product with yield of 0.05-0.09 g g-1. This fungus had ethanol, biomass and glycerol yields of 0.33-0.41, 0.06-0.12, and 0.03-0.04 g g-1, respectively. 

  • 2. Abedinifar, Sorahi
    et al.
    Karimi, Keikhosro
    University of Borås, School of Engineering.
    Khanahmadi, Morteza
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Ethanol production by Mucor indicus and Rhizapus oryzae from rice straw by separate hydrolysis and fermentation2009In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 33, no 5, p. 828-833Article in journal (Refereed)
    Abstract [en]

    Rice straw was successfully converted to ethanol by separate enzymatic hydrolysis and fermentation by Mucor indicus, Rhizopus oryzae, and Saccharomyces cerevisiae. The hydrolysis temperature and pH of commercial cellulase and beta-glucosidase enzymes were first investigated and their best performance obtained at 45 degrees C and pH 5.0. The pretreatment of the straw with dilute-acid hydrolysis resulted in 0.72 g g (1) sugar yield during 48 h enzymatic hydrolysis, which was higher than steam-pretreated (0.60 g g (1)) and untreated straw (0.46 g g(-1)). Furthermore, increasing the concentration of the dilute-acid pretreated straw from 20 to 50 and 100 g L-1 resulted in 13% and 16% lower sugar yield, respectively. Anaerobic cultivation of the hydrolyzates with M. indicus resulted in 0.36-0.43 g g(-1) ethanol, 0.11-0.17 g g(-1) biomass, and 0.04-0.06 g g(-1) glycerol, which is comparable with the corresponding yields by S. cerevisiae (0.37-0.45 g g(-1) ethanol, 0.04-0.10 g g(-1) biomass and 0.05-0.07 glycerol). These two fungi produced no other major metabolite from the straw and completed the cultivation in less than 25 h. However, R. oryzae produced lactic acid as the major by-product with yield of 0.05-0.09 g g(-1). This fungus had ethanol, biomass and glycerol yields of 0.33-0.41, 0.06-0.12, and 0.03-0.04 g g(-1), respectively. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

  • 3.
    Ahlberg-Eliasson, Karin
    et al.
    Swedish Rural Economy and Agricultural Society, Sweden.
    Nadeau, Elisabet
    Swedish Rural Economy and Agricultural Society, Sweden; SLU Swedish University of Agricultural Sciences, Sweden.
    Levén, Lotta
    RISE - Research Institutes of Sweden, Bioscience and Materials, Agrifood and Bioscience.
    Schnürer, Anna
    SLU Swedish University of Agricultural Sciences, Sweden.
    Production efficiency of Swedish farm-scale biogas plants2017In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 97, p. 27-37Article in journal (Refereed)
    Abstract [en]

    Biogas from agricultural waste streams represents an important way to produce fossil-free energy, allow nutrient recycling and reduce greenhouse gas emissions. However, biogas production from agricultural substrates is currently far from reaching its full potential. In Sweden, the number of biogas plants and their output have increased in recent years, but they are still experiencing harsh economic conditions. A recent evaluation (2010–2015) of 31 farm-scale biogas production facilities in Sweden sought to identify parameters of importance for further positive development. In this paper, data on plant operation, gas yield and digestate quality for 27 of these plants are summarised and statistically analysed to investigate factors that could allow an increase in overall biogas production and in nutrient content in the digestate. The analysis showed that addition of co-substrates to manure results in higher gas production, expressed as both specific methane potential and volumetric gas production, than when manure is the sole substrate. Use of co-substrate was also found to be influential for the nutrient content of the digestate. These observed improvements caused by co-digestion should be considered when subsidy systems for manure-based biogas processes are being created, as they could also improve the economics of biogas production. However, to achieve higher efficiency in existing biogas plants and to improve the situation for future investments, a more detailed, long-term evaluation programme should also be considered.

  • 4.
    Ahmed, Ali
    et al.
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Uddin, Gazi Salah
    Linköping University, Department of Management and Engineering, Economics. Linköping University, Faculty of Arts and Sciences.
    Sohag, Kazi
    Institute of Climate Change, Universiti Kebangsaan, Malaysia.
    Biomass energy, technological progress and the environmental Kuznets curve: Evidence from selected European countries2016In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 90, p. 202-208Article in journal (Refereed)
    Abstract [en]

    We examine the causal relationship between economic growth and CO2 emissions in a panel of 24 European countries from 1980 to 2010. Using an analytical framework that considers pooled mean group estimations in a dynamic heterogeneous panel setting, we show that there is an inverted U-shaped relationship between CO2 emissions and economic growth in the long run and that there is no such relationship in the short run. In particular, we find that biomass energy is insignificantly linked to CO2 emission. However, technological innovation significantly facilitates reduction of CO2 emissions in the investigated countries. Altogether, our study implies that economic growth and environmental quality can be achieved simultaneously, which opens up new insights for policy-makers for sustainable economic development via implementation of renewable energy consumption through technological innovation.

  • 5. Andersson, J.
    et al.
    Lundgren, J.
    Marklund, Magnus
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Methanol production via pressurized entrained flow biomass gasification: Techno-economic comparison of integrated vs. stand-alone production2014In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 64, p. 256-268Article in journal (Refereed)
    Abstract [en]

    The main objective with this work was to investigate techno-economically the opportunity for integrated gasification-based biomass-to-methanol production in an existing chemical pulp and paper mill. Three different system configurations using the pressurized entrained flow biomass gasification (PEBG) technology were studied, one stand-alone plant, one where the bark boiler in the mill was replaced by a PEBG unit and one with a co-integration of a black liquor gasifier operated in parallel with a PEBG unit. The cases were analysed in terms of overall energy efficiency (calculated as electricity-equivalents) and process economics. The economics was assessed under the current as well as possible future energy market conditions. An economic policy support was found to be necessary to make the methanol production competitive under all market scenarios. In a future energy market, integrating a PEBG unit to replace the bark boiler was the most beneficial case from an economic point of view. In this case the methanol production cost was reduced in the range of 11-18 Euro per MWh compared to the stand-alone case. The overall plant efficiency increased approximately 7%-units compared to the original operation of the mill and the non-integrated stand-alone case. In the case with co-integration of the two parallel gasifiers, an equal increase of the system efficiency was achieved, but the economic benefit was not as apparent. Under similar conditions as the current market and when methanol was sold to replace fossil gasoline, co-integration of the two parallel gasifiers was the best alternative based on received IRR. © 2014 Elsevier Ltd.

  • 6.
    Andersson, Jim
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Lundgren, Joakim
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Marklund, Magnus
    Energy Technology Centre, Piteå.
    Methanol production via pressurized entrained flow biomass gasification: Techno-economic comparison of integrated vs. stand-alone production2014In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 64, p. 256-268Article in journal (Refereed)
    Abstract [en]

    The main objective with this work was to investigate techno-economically the opportunity for integrated gasification-based biomass-to-methanol production in an existing chemical pulp and paper mill. Three different system configurations using the pressurized entrained flow biomass gasification (PEBG) technology were studied, one stand-alone plant, one where the bark boiler in the mill was replaced by a PEBG unit and one with a co-integration of a black liquor gasifier operated in parallel with a PEBG unit. The cases were analysed in terms of overall energy efficiency (calculated as electricity-equivalents) and process economics. The economics was assessed under the current as well as possible future energy market conditions. An economic policy support was found to be necessary to make the methanol production competitive under all market scenarios. In a future energy market, integrating a PEBG unit to replace the bark boiler was the most beneficial case from an economic point of view. In this case the methanol production cost was reduced in the range of 11–18 Euro per MWh compared to the stand-alone case. The overall plant efficiency increased approximately 7%-units compared to the original operation of the mill and the non-integrated stand-alone case. In the case with co-integration of the two parallel gasifiers, an equal increase of the system efficiency was achieved, but the economic benefit was not as apparent. Under similar conditions as the current market and when methanol was sold to replace fossil gasoline, co-integration of the two parallel gasifiers was the best alternative based on received IRR.

  • 7.
    Andersson, Viktor
    et al.
    Chalmers, Sweden.
    Broberg, Sarah
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Hackl, Roman
    Chalmers, Sweden.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Berntsson, Thore
    Chalmers, Sweden.
    Algae-based biofuel production as part of an industrial cluster2014In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 71, p. 113-124Article in journal (Refereed)
    Abstract [en]

    This paper presents a study on the production of biofuels from algae cultivated in municipal wastewater in Gothenburg, Sweden. A possible biorefinery concept is studied based on two cases; Case A) combined biodiesel and biogas production, and Case B) only biogas production. The cases are compared in terms of product outputs and impact on global CO2 emissions mitigation. The area efficiency of the algae-based biofuels is also compared with other biofuel production routes. The study investigates the collaboration between an algae cultivation, biofuel production processes, a wastewater treatment plant and an industrial cluster for the purpose of utilizing material flows and industrial excess heat between the actors. This collaboration provides the opportunity to reduce the CO2 emissions from the process compared to a stand-alone operation. The results show that Case A is advantageous to Case B with respect to all studied factors. It is found that the algae-based biofuel production routes investigated in this study has higher area efficiency than other biofuel production routes. The amount of algae-based biofuel possible to produce corresponds to 31 MWfuel for Case A and 26 MWfuel in Case B.

  • 8. Anugwom, Ikenna
    et al.
    Eta, Valerie
    Virtanen, Pasi
    Mäki-Arvela, Paivi
    Hedenström, Mattias
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Yibo, Ma
    Hummel, Micheal
    Sixta, Herbert
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Laboratory of Industrial Chemistry and Reaction Engineering, Process Chemistry Centre, Åbo Akademi University.
    Towards optimal selective fractionation for Nordic woody biomass using novel amine–organic superbase derived switchable ionic liquids (SILs)2014In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 70, p. 373-381Article in journal (Refereed)
    Abstract [en]

    Abstract Improved fractionation process conditions for wood dissolution with switchable ionic liquids (SILs) were determined. The short time, high temperature (STHT) system was introduced as a selective and efficient way to extract components from lignocellulosic material. A SIL based on monoethanol amine (MEA) and 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) formed via coupling with SO2, was applied as a solvent in a 1:3 weight ratio with water. In essence, selective dissolution of mainly lignin was achieved by means of the aqueous SIL at 160 °C (∼6.1 bar corresponding to the vapor pressure of water) in 2 h and in a pressure vessel, for both hard- and soft-wood. About 95 wt-% of wood lignin was extracted. The dissolved components in the spent SIL were recovered by the addition of an anti-solvent whereupon over 70% of the dissolved components were recovered; the recovered fraction contained 19 wt-% hemicellulose while the rest of the material was in essence lignin. The non-dissolved, fluffy material contained ∼70 wt-% cellulose and ∼20 wt-% hemicellulose – a consistency resembling that of Kraft pulp.

  • 9.
    Arrhenius, Karine
    et al.
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Yaghooby, Haleh
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Rosell, Lars
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Büker, Oliver
    RISE - Research Institutes of Sweden, Bioscience and Materials, Chemistry and Materials.
    Culleton, Lucy
    NPL National Physical Laboratory, UK.
    Bartlett, Sam
    NPL National Physical Laboratory, UK.
    Murugan, Arul
    NPL National Physical Laboratory, UK.
    Brewer, Paul
    NPL National Physical Laboratory, UK.
    Li, Jianrong
    VSL Van Swinden Laboratorium B.V., The Netherlands.
    van der Veen, Adriaan M. H.
    VSL Van Swinden Laboratorium B.V., The Netherlands.
    Krom, Iris
    VSL Van Swinden Laboratorium B.V., The Netherlands.
    Lestremau, Francoise
    INERIS Institut national de l'environnement industriel et des risques, France.
    Beranek, Jan
    ČMI Česky metrologicky institut, Czech Republic.
    Suitability of vessels and adsorbents for the short-term storage of biogas/biomethane for the determination of impurities – Siloxanes, sulfur compounds, halogenated hydrocarbons, BTEX2017In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 105, p. 127-135Article in journal (Refereed)
    Abstract [en]

    Biogas is a renewable energy source with many different production pathways and various excellent opportunities to use, for example as vehicle fuel (biomethane). Reliable analytical methodologies for assessing the quality of the gas are critical to ensure that the gas can technically and safely be used. An essential part of any procedure aiming to determine the quality is the sampling and the transfer to the laboratory. One of the greatest challenges is then to ensure that the composition of the sample collected does not change between the time of sampling and the analysis. The choice of the sampling vessel to be used must be made only after fully assessing its short-term stability. In this paper, the results from short-term stability studies in different vessels (cylinders, bags and sorbents) are presented for siloxanes, BTEX, halogenated hydrocarbons and sulfur compounds. Storage of dry gas at high pressure (> 6 MPa) appears to be a good alternative however it is currently challenging to find an optimal treatment of the cylinders for all species to be assessed in biogas/biomethane. At lower pressure, adsorption effects on the inner surface of the cylinders have been observed. The use of bags and sorbent tubes also shows limitation. No existing sorbent tubes are sufficiently universal as to trap all possible impurities and high boiling compounds may adsorbed on the inner surface of the bags walls. Moreover, the presence of water when storing biogas most certainly impacts the storage stability of compounds in most vessels. Using at least two sampling methods for a given compound and comparing results will allow taking into account the eventual effects of water vapour, and adsorption on the inner surface of the vessels.

  • 10.
    Basile, Francesco
    et al.
    University of Bologna.
    Albertazzi, Simone
    University of Bologna.
    Barbera, David
    University of Bologna.
    Benito, Patricia
    University of Bologna.
    Einvall, Jessica
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Brandin, Jan
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Fornasari, G.
    University of Bologna.
    Trifiro, Ferrucio
    University of Bologna.
    Vaccari, A.
    University of Bologna.
    Steam reforming of hot gas from gasified wood types and miscanthus biomass2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no Supplement 1, p. S116-S122Article in journal (Refereed)
    Abstract [en]

    The reforming of hot gas generated from biomass gasification and high temperature gas filtration was studied in order to reach the goal of the CHRISGAS project: a 60% of synthesis gas (as x(H2)+ x(CO) on a N2 and dry basis) in the exit gas, which can be converted either into H2 or fuels. A Ni-MgAl2O4 commercial-like catalyst was tested downstream the gasification of clean wood made of saw dust, waste wood and miscanthus as herbaceous biomass. The effect of the temperature and contact time on the hydrocarbon conversion as well as the characterization of the used catalysts was studied. Low (<600 °C), medium (750°C–900 °C) and high temperature (900°C–1050 °C) tests were carried out in order to study, respectively, the tar cracking, the lowest operating reformer temperature for clean biomass, the methane conversion achievable as function of the temperature and the catalyst deactivation. The results demonstrate the possibility to produce an enriched syngas by the upgrading of the gasification stream of woody biomass with low sulphur content. However, for miscanthusthe development of catalysts with an enhanced resistance to sulphur poison will be the key point in the process development.

  • 11.
    Bengtsson, Sune
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    The CHRISGAS Project2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no S1, p. S2-S7Article in journal (Refereed)
  • 12.
    Bengtsson, Sune
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    VVBGC demonstration plant activities in Värnamo2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no S1, p. S16-S20Article in journal (Refereed)
  • 13.
    Berghel, Jonas
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Renström, Roger
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Superheated steam drying of sawdust in continuous feed spouted beds: a design perspective2014In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 71, no 0, p. 228-234Article in journal (Refereed)
    Abstract [en]

    Spouted bed drying technology shows promising results for the drying of unscreened sawdust in superheated steam. In this paper, the experiences from designing, running and evaluating two spouted bed continuous feed dryers are presented. Stable running conditions and drying results have been achieved. This has been particularly important for sawdust that will be compressed into pellets or briquettes. The spouted bed superheated steam dryer also shows high potential for energy efficient integration into sawmills. Our recommendation is thus, to use the outlet steam temperature as the control parameter for the outlet moisture content. A drying rate above and one below the fibre saturation level, can be identified. Visual observations through the viewing glass in the drying zone in both the dryers clearly showed that not all of the material participated in the spout at all times; there were, however, no indications of dead zones. A heat transfer analysis indicated that only about 70% of the surface area of the material was in thermal contact with the steam. This paper sums up the experiences regarding drying properties, control and system properties obtained when sawdust is dried using superheated steam as the drying medium. Further work on standardised dryers in series or in parallel is necessary to increase the capacity in the spouted bed dryer.

  • 14.
    Bernotat, Knut
    et al.
    KTH, Superseded Departments, Industrial Economics and Management.
    Sandberg, Thomas
    KTH, Superseded Departments, Industrial Economics and Management.
    Biomass fired small-scale CHP in Sweden and the Baltic States: a case study on the potential of clustered dwellings2004In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 27, no 6, p. 521-530Article in journal (Refereed)
    Abstract [en]

    Sweden as well as the three Baltic states has an abundant supply of biomass, mostly wood waste. Much of it goes into district heating (DH), which has expanded continuously since the first system started 50 years ago. DH now accounts for 43% of the heating consumption and a further expansion is possible in many directions. Firstly existing DH systems can be enlarged, secondly DH can be upgraded to combined heat and power (CHP) to a much larger extent, thirdly new DH (and CHP) systems can be implemented in many smaller places down to 1000 inhabitants or less. The last alternative, biomass and especially pellets fired small-scale cogeneration in combination with local heating networks, is the topic for this paper. It presents a method to estimate the potential for small-scale DH and CHP and results from a "test" area in southeast Sweden. The method estimates local heat demand using databases with individual and statistical property data. It identifies areas with clusters of buildings where the heat demand is enough to implement decentralized small DH networks if possible in combination with small-scale CHP. In the event for Swedish circumstances very sparsely populated test area of 36 x 48 km(2) with around 8000 inhabitants, the total heat consumption in residential buildings is estimated to 84 GWh. When we have identified the areas with clusters of buildings, we have set the minimum heat consumption in such an area to 500 MW h. The area size is varied in 250 m steps from 250 x 250 m(2) to 1000 x 1000 m(2). For the four area sizes, the method then identifies and locates 30, 38, 38,30, respectively, clustered areas with a potential for small-scale DH and CHP worth investing closer.

  • 15.
    Bernstad Saraiva, Anna
    et al.
    COPPE UFRJ, Brazil.
    Valle, Rogerio A. B.
    COPPE UFRJ, Brazil.
    Bosque, A.E.S., Jr.
    Fibria CElulose SA, Brazil.
    Berglin, Niklas
    RISE - Research Institutes of Sweden, Bioeconomy. RISE, Innventia.
    von Schenck, A.
    ÅF AB, Sweden.
    Provision of pulpwood and short rotation eucalyptus in Bahia, Brazil: Environmental impacts based on lifecycle assessment methodology2017In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 105, p. 41-50Article in journal (Refereed)
    Abstract [en]

    Environmental impacts from cultivation of eucalyptus pulpwood and short rotation eucalyptus in northeast Brazil were investigated using lifecycle assessment methodology. The assessment considers all relevant inputs and outputs, as well as direct land use changes, assuming conversion of grassland (pasture) to areas for eucalyptus plantation. Results show that production of pulpwood eucalyptus is beneficial compared to short rotation eucalyptus in relation to all assessed impact categories, except for climate change (greenhouse gas emissions = 47 kg CO2-eq. t DM−1 pulpwood eucalyptus and 35 kg CO2-eq. t DM−1 short rotation eucalyptus). Excluding emissions from direct land use changes would increase overall GWP from investigated systems with around 5–6%, and changing the assumed land-use prior to land conversion is of decisive character for overall GWP-results from the assessed eucalyptus production systems. Modeling of nutrient balances in the short rotation production system shows a potential need to increase the input of mineral fertilizer in order to compensate for nutrient losses. This would increase environmental impacts from the short rotation system, making pulpwood eucalyptus preferable in relation to all assessed impact categories.

  • 16. Björheden, Rolf
    et al.
    Gullberg, Tomas
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Johansson, Jerry
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Systems analyses for harvesting small trees for forest fuel in urban forestry2003In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 24, no 4-5Article in journal (Refereed)
  • 17.
    Blennow, Kristina
    et al.
    Sveriges lantbruksuniversitet.
    Persson, Erik
    Sveriges Lantbruksuniversitet.
    Lindner, Marcus
    Pacheco Faias, Sònia
    Hanewinkel, Hanewinkel
    Forest owner motivations and attitudes towards supplying biomass for energy in Europe2014In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 67, p. 223-230Article in journal (Refereed)
    Abstract [en]

    The European Commission expects the use of biomass for energy in the EU to increasesignificantly between 2010 and 2020 to meet a legally binding target to cover at least 20%of EU’s total energy use from renewable sources in 2020. According to estimates made bythe member states of the EU, the direct supply of biomass from forests is expected toincrease by 45% on a volume basis between 2006 and 2020 in response to increasingdemand (Beurskens LWM, Hekkenberg M, Vethman P. Renewable energy projections aspublished in the national renewable energy action plans of the European Member states.ECN and EEA; 2011. http://https://www.ecn.nl/docs/library/report/2010/e10069.pdf[accessed 25.04.2014]; Dees M, Yousef A, Ermert J. Analysis of the quantitative tables ofthe national renewable energy action plans prepared by the 27 European Union MemberStates in 2010. BEE working paper D7.2. Biomass Energy Europe project. FELIS e Departmentof Remote Sensing and landscape information Systems, University of Freiburg,Germany; 2011). Our aims were to test the hypotheses that European private forestowners’ attitudes towards supplying woody biomass for energy (1) can be explained bytheir responses to changes in prices and markets and (2) are positive so that the forestbiomass share of the EU 2020 renewable energy target can be met. Based on survey datacollected in 2010 from 800 private forest owners in Sweden, Germany and Portugal ourresults show that the respondents’ attitudes towards supplying woody biomass for energycannot be explained as direct responses to changes in prices and markets. Our results,furthermore, imply that European private forest owners cannot be expected tosupply the requested amounts of woody biomass for energy to meet the forest biomassshare of the EU 2020 renewable energy target, at least if stemwood is to play theimportant role as studies by Verkerk PJ, Anttila P, Eggers J, Lindner M, Asikainen A. Therealisable potential supply of woody biomass fromforests in the European Union. For EcolManag 2011;261: 2007e2015, UNECE and FAO. The European forest sector outlook study II 2010e2030. United Nations, New York and Geneva; 2011 [abbreviated to EFSOS II] andElbersen B, Staritsky I, Hengeveld G, Schelhaas MJ, Naeff H, Bo¨ ttcher H. Atlas of EUbiomass potentials; 2012. Available from: http://www.biomassfutures.eu [accessed14.10.2013] suggest.

  • 18.
    Boman, Christoffer
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Energy Technology Center, Piteå, Sweden.
    Nordin, Anders
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Thanning, Lennart
    FOI.
    Effects of increased small-scale biomass pellet combustion on ambient air quality in residential areas: A parametric dispersion modeling study2003In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 24, no 6, p. 465-474Article in journal (Refereed)
    Abstract [en]

    Sweden's goals of contemporaneously reducing CO2 emissions and phasing out nuclear power will require a maximum utilization of biomass fuels. This would imply a significant shift from electricity and fuel oil to biomass generated heat, but must also be accomplished without a deterioration of the local air quality. The most suitable energy carrier seems to be pelletized biomass fuels with their associated low emissions and considerable residential conversion potential. Using an underlying statistical design, a parametric dispersion modeling study was performed to estimate and illustrate the combined effects of source-specific, meteorological and modeling variables on the ambient air quality in a typical residential area for different conversion scenarios. The work nicely illustrated the benefits of combining statistical designs with model calculations. It further showed that the concentration of combustion related ambient THC was strongly related to conditions affecting the source strength, but only weakly to the dispersion conditions and model variables. Time of year (summer or winter); specific emission performance; extent of conversion from electricity; conversion from wood log combustion; and specific efficiency of the pellet appliances showed significant effects in descending order. The effects of local settings and model variables were relatively small, making the results more generally applicable. To accomplish the desired conversion to renewable energy in an ecologically and sustainable way, the emissions would have to be reduced to a maximum advisable limit of (given as CH4). Further, the results showed the potential positive influence by conversion from wood log to low emission pellet combustion.

  • 19. Boman, Christoffer
    et al.
    Nordin, Anders
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Westerholm, R.
    Pettersson, Esbjörn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Evaluation of a constant volume sampling setup for residential biomass fired appliances: Influence of dilution conditions on particulate and PAH emissions2005In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 29, no 4, p. 258-268Article in journal (Refereed)
    Abstract [en]

    Increased concerns about particulate matter (PM) and polycyclic aromatic hydrocarbons (PAH) emissions from residential biomass combustion and their potential health effects, motivates detailed emission measurements under controlled conditions. Traditional sampling in raw flue gases can suffer from drawbacks mainly related to transient flows and the condensable nature of organic compounds. Whole flow dilution with constant volume sampling (CVS) is an alternative method but different sampling conditions may, however, influence the emission characteristics. The objective was to design a CVS system for emission measurements in residential biomass fired appliances and determine the influence of dilution sampling conditions on the characteristics and distributions of PM and PAH. Softwood pellets were combusted in a pellet stove with variations in; dilution ratio (3-7x), sampling temperature (45-75°C), dilution tunnel residence time (2-4 s) and fuel load (2.3 and 4.8 kW) according to a statistical experimental design. The sampling conditions did not influence either the emission concentrations of PM, CO and NO or the particle size distribution. Variations in residence time had no significant effect on any studied emission parameter. However, increased concentrations of organic gaseous carbon (OGC) and PAH were observed with increased dilution ratio. The distribution between particulate and semivolatile phase was influenced for 12 of the 37 analyzed PAH compounds, mainly by increased fractions of semivolatile material at higher sampling temperature. No influence of sampling temperature was observed for the concentrations of PAHtot or the dominating PAH compounds, i.e. phenanthrene, fluoranthene and pyrene. The results together with practical considerations also suggest sampling at 50±5°C and 3-4 times dilution as robust and applicable conditions in the presently designed setup. © 2005 Elsevier Ltd. All rights reserved.

  • 20.
    Boman, Christoffer
    et al.
    Umeå university.
    Nordin, Anders
    Umeå universitet.
    Westerholm, Roger
    Stockholm University.
    Pettersson, Esbjörn
    Evaluation of a constant volume sampling set-up for residential biomass fired appliances: influence of dilution conditions on particulate and PAH emissions2005In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 29, p. 258-268Article in journal (Refereed)
  • 21.
    Boman, Christoffer
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Nordin, Anders
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Westerholm, Roger
    Pettersson, Esbjörn
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics, Energy Technology and Thermal Process Chemistry.
    Evaluation of a constant volume sampling set-up for residential biomass fired appliances: influence of dilution conditions on particulate and PAH emissions2005In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 29, no 4, p. 258-268Article in journal (Refereed)
    Abstract [en]

    Increased concerns about particulate matter (PM) and polycyclic aromatic hydrocarbons (PAH) emissions from residentialbiomass combustion and their potential health effects, motivates detailed emission measurements under controlled conditions. Traditional sampling in raw flue gases can suffer from drawbacks mainly related to transient flows and the condensable nature of organic compounds. Whole flow dilution with constantvolumesampling (CVS) is an alternative method but different samplingconditions may, however, influence the emission characteristics. The objective was to design a CVS system for emission measurements in residentialbiomassfiredappliances and determine the influence of dilutionsamplingconditions on the characteristics and distributions of PM and PAH. Softwood pellets were combusted in a pellet stove with variations in; dilution ratio (3–7x), sampling temperature (45–75 °C), dilution tunnel residence time (2–4 s) and fuel load (2.3 and 4.8 kW) according to a statistical experimental design. The samplingconditions did not influence either the emission concentrations of PM, CO and NO or the particle size distribution. Variations in residence time had no significant effect on any studied emission parameter. However, increased concentrations of organic gaseous carbon (OGC) and PAH were observed with increased dilution ratio. The distribution between particulate and semivolatile phase was influenced for 12 of the 37 analyzed PAH compounds, mainly by increased fractions of semivolatile material at higher sampling temperature. No influence of sampling temperature was observed for the concentrations of PAHtot or the dominating PAH compounds, i.e. phenanthrene, fluoranthene and pyrene. The results together with practical considerations also suggest sampling at 50±5 °C and 3–4 times dilution as robust and applicable conditions in the presently designed setup.

  • 22. Brage, C.
    et al.
    Yu, Q. Z.
    Chen, G. X.
    Sjöström, Krister
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Tar evolution profiles obtained from gasification of biomass and coal2000In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 18, no 1, p. 87-91Article in journal (Refereed)
    Abstract [en]

    The tar content of the product gases from gasification of biomass is one of the major factors affecting the subsequent process stages. In this work, evolution profiles of the main tar constituents, i.e. benzene, toluene, indene, naphthalene and phenol were obtained during about 1 h gasification runs of biomass and coal in a pressurised fluidised-bed at 700 and 900 degrees C, 0.4 MPa. Sampling and analysis was achieved, using the solid-phase adsorption (SPA) method, previously developed in our laboratory. Our main objectives were: (1) to illustrate the usefulness of the SPA method; (2) to shed new light on the main factors governing tar evolution. It was found that temperature and the type of feedstock used mainly affected tar yields. For both biomass and coal the concentration of tar products decreased with increasing run time at a rate that was fastest initially. This behaviour, which was much more pronounced for coal, provides evidence that char catalytically affects tar evolution. Accordingly, char accumulates in the bed to a various extent depending on fuel and gradually approaching steady state. Biomass char, contrary to coal char, is readily oxidised during gasification, and thus only small steady-state amounts are available to catalyse tar cracking reactions.

  • 23. Brandin, Jan
    et al.
    Liliedahl, Truls
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Unit operations for production of clean hydrogen-rich synthesis gas from gasified biomass2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, p. S8-S15Article in journal (Refereed)
    Abstract [en]

    The rebuild of the Vaxjo Varnamo Biomass Gasification Center (VVBGC) integrated gasification combined cycle (IGCC) plant into a plant for production of a clean hydrogen rich synthesis gas requires an extensive adaptation of conventional techniques to the special chemical and physical needs found in a gasified biomass environment. The CHRISGAS project has, in a multitude of areas, been responsible for the research and development activities associated with the rebuild. In this paper the present status and some of the issues concerning the upgrading of the product gas from gasified biomass into synthesis gas are addressed. The purpose is to serve as an introduction to the scientific papers written by the partners in the consortium concerning the unit operations of the process.

  • 24.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Liliedahl, Truls
    Royal Institute of Technology.
    Unit operations for production of clean hydrogen-rich synthesis gas from gasified biomass2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no Supplement 1, p. S8-S15Article in journal (Refereed)
    Abstract [en]

    The rebuild of the Växjö Värnamo Biomass Gasification Center (VVBGC) integrated gasification combined cycle (IGCC) plant into a plant for production of a clean hydrogen rich synthesis gas requires an extensive adaptation of conventional techniques to the special chemical and physical needs found in a gasified biomass environment. The CHRISGAS project has, in a multitude of areas, been responsible for the research and development activities associated with the rebuild. In this paper the present status and some of the issues concerning the upgrading of the product gas from gasified biomass into synthesis gas are addressed. The purpose is to serve as an introduction to the scientific papers written by the partners in the consortium concerning the unit operations of the process.

  • 25. Börjesson, Pål
    et al.
    Gustavsson, Leif
    Christersson, L
    Linder, S
    Future Production and Utilisation of Biomass in Sweden: potentials and CO~2 mitigation1997In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 13, no 6, p. 399-412Article in journal (Refereed)
  • 26. Börjesson, Pål
    et al.
    Gustavsson, Leif
    Christersson, L
    Linder, S
    Future Production and Utilisation of Biomass in Sweden: potentials and CO~2 mitigation1997In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 13, no 6, p. 399-412Article in journal (Refereed)
  • 27.
    Carlos-Pinedo, Sandra
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Wang, Zhao
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Methane yield from SS-AD: Experiences to learn by a full spectrum analysis at laboratory-, pilot- and full-scale2019In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 127, article id 105270Article, review/survey (Refereed)
    Abstract [en]

    Solid-state anaerobic digestion (SS-AD) takes place when solid content of the substrate is higher than 15%. Some advantages of this technology have been recognized as e.g., less required water added to raw feedstock and consequently minimized digester size and cost, higher volumetric organic loading rates (OLR) that may lead to higher efficiency methane yield and better acceptance of a wide range of feedstocks. However, scientific studies of SS-AD at pilot- and full-scale are very few and difficulties have been reported in operating SS-AD, especially when the system undergoes a scale-up, where methane production is the purpose. As a result, this review gives a summary of scientific studies for SS-AD processes at laboratory-, pilot- and full-scale, where a great diversity of substrate composition, reactor design and operational parameters have been categorized, and their performances in terms of methane yield have been analyzed. This, in turn, helps to identify that factors affecting methane yields at different scales arise mainly from operational conditions as well as the characteristic of feedstocks. This review even contributes to suggest several strategies for improvement of methane yield at full-scale.

  • 28.
    Carlson, A
    Linköping University, Department of Mechanical Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Energy system analysis of the inclusion of monetary values of environmental damage2002In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 22, no 3, p. 169-177Article in journal (Refereed)
    Abstract [en]

    This is an analysis of the effect on the technical solution when monetary values of externalities are included in a model for optimising energy systems. The focus of the study is on heating in domestic houses, non-residential premises, multi-dwelling buildings and district heating systems. The included monetary values of damage to the environment and health are those resulting from atmospheric emissions Of CO2, NOx, SO2 and particulates. The estimates are taken from the literature. An optimising method based on linear programming is used and the result is an optimal mix of energy carriers as well as new and existing heating plants that minimise the costs of satisfying a demand for heat. Furthermore, a calculation is made of the externality cost resulting from the energy system. The analysis makes it possible to compare the technical and economic differences of an energy system based on business economics to a system with greater emphasis on socio-economics. Generally speaking, it is cost-effective to take externality costs into consideration at the planning stage instead of correcting the damage later. The results show that by considering externality costs the total discounted cost of the energy system would be approximately 30% lower than today. Furthermore, the use of pellets and wood chips should be substantially larger in all of the studied regions. (C) 2002 Elsevier Science Ltd. All rights reserved.

  • 29.
    Difs, Kristina
    et al.
    Division of Energy Systems, Department of Mechanical Engineering, Linköping Institute of Technology.
    Wetterlund, Elisabeth
    Trygg, Louise
    Division of Energy Systems, Department of Mechanical Engineering, Linköping Institute of Technology.
    Söderström, Mats
    Division of Energy Systems, Department of Mechanical Engineering, Linköping Institute of Technology.
    Biomass gasification opportunities in a district heating system2010In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 34, no 5, p. 637-651Article in journal (Refereed)
    Abstract [en]

    This paper evaluates the economic effects and the potential for reduced CO2 emissions when biomass gasification applications are introduced in a Swedish district heating (DH) system. The gasification applications included in the study deliver heat to the DH network while producing renewable electricity or biofuels. Gasification applications included are: external superheater for steam from waste incineration (waste boost, WB), gas engine CHP (BIGGE), combined cycle CHP (BIGCC) and production of synthetic natural gas (SNG) for use as transportation fuel. Six scenarios are used, employing two time perspectives – short-term and medium-term – and differing in economic input data, investment options and technical system. To evaluate the economic performance an optimisation model is used to identify the most profitable alternatives regarding investments and plant operation while meeting the DH demand. This study shows that introducing biomass gasification in the DH system will lead to economic benefits for the DH supplier as well as reduce global CO2 emissions. Biomass gasification significantly increases the potential for production of high value products (electricity or SNG) in the DH system. However, which form of investment that is most profitable is shown to be highly dependent on the level of policy instruments for biofuels and renewable electricity. Biomass gasification applications can thus be interesting for DH suppliers in the future, and may be a vital measure to reach the 2020 targets for greenhouse gases and renewable energy, given continued technology development and long-term policy instruments.

  • 30.
    Difs, Kristina
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Trygg, Louise
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Biomass gasification opportunities in a district heating system2010In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 34, no 5, p. 637-651Article in journal (Refereed)
    Abstract [en]

    This paper evaluates the economic effects and the potential for reduced CO2 emissions when biomass gasification applications are introduced in a Swedish district heating (DH) system. The gasification applications included in the study deliver heat to the DH network while producing renewable electricity or biofuels. Gasification applications included are: external superheater for steam from waste incineration (waste boost, WE), gas engine CHP (BIGGE), combined cycle CHP (BIGCC) and production of synthetic natural gas (SNG) for use as transportation fuel. Six scenarios are used, employing two time perspectives - short-term and medium-term - and differing in economic input data, investment options and technical system. To evaluate the economic performance an optimisation model is used to identify the most profitable alternatives regarding investments and plant operation while meeting the DH demand. This study shows that introducing biomass gasification in the DH system will lead to economic benefits for the DH supplier as well as reduce global CO2 emissions. Biomass gasification significantly increases the potential for production of high value products (electricity or SNG) in the DH system. However, which form of investment that is most profitable is shown to be highly dependent on the level of policy instruments for biofuels and renewable electricity. Biomass gasification applications can thus be interesting for DH suppliers in the future, and may be a vital measure to reach the 2020 targets for greenhouse gases and renewable energy, given continued technology development and long-term policy instruments.

  • 31.
    Dornburg, Veronika
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Engineering, Physics and Mathematics.
    Estimating GHG emission mitigation supply curves of large-scale biomass use on a country level2007In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 31, no 1, p. 46-65Article in journal (Refereed)
    Abstract [en]

    This study evaluates the possible influences of a large-scale introduction of biomass material and energy systems and their market volumes on land, material and energy market prices and their feedback to greenhouse gas (GHG) emission mitigation costs. GHG emission mitigation supply curves for large-scale biomass use were compiled using a methodology that combines a bottom-up analysis of biomass applications, biomass cost supply curves and market prices of land, biornaterials and bioenergy carriers. These market prices depend on the scale of biomass use and the market volume of materials and energy carriers and were estimated using own-price elasticities of demand. The methodology was demonstrated for a case study of Poland in the year 2015 applying different scenarios on economic development and trade in Europe. For the key technologies considered, i.e. medium density fibreboard, poly lactic acid, electricity and methanol production, GHG emission mitigation costs increase strongly with the scale of biomass production. Large-scale introduction of biomass use decreases the GHG emission reduction potential at costs below 50EURO/Mg CO2eq with about 13-70% depending on the scenario. Biomaterial production accounts for only a small part of this GHG emission reduction potential due to relatively small material markets and the subsequent strong decrease of biomaterial market prices at large scale of production. GHG emission mitigation costs depend strongly on biomass supply curves, own-price elasticity of land and market volumes of bioenergy carriers. The analysis shows that these influences should be taken into account for developing biomass implementations strategies.

  • 32. Ebrahimi, Fatemeh
    et al.
    Khanahmadi, Morteza
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Ethanol production from bread residues2008In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 32, no 4, p. 333-337Article in journal (Refereed)
  • 33.
    Einvall, Jessica
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Parsland, Charlotte
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Benito, Patricia
    University of Bologna.
    Basile, Francesco
    University of Bologna.
    Brandin, Jan
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    High temperature water-gas shift step in the production of clean hydrogen rich synthesis gas from gasified biomass2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no Supplement 1, p. S123-S131Article in journal (Refereed)
    Abstract [en]

    The possibility of using the water-gas shift (WGS) step for tuning the H2/CO-ratio in synthesis gas produced from gasified biomass has been investigated in the CHRISGAS (Clean Hydrogen Rich Synthesis Gas) project. The synthesis gas produced will contain contaminants such as H2S, NH3 and chloride components. As the most promising candidate FeCr catalyst, prepared in the laboratory, was tested. One part of the work was conducted in a laboratory set up with simulated gases and another part in real gases in the 100 kW Circulating Fluidized Bed (CFB) gasifier at Delft University of Technology. Used catalysts from both tests have been characterized by XRD and N2 adsoption/desorption at −196 °C.

    In the first part of the laboratory investigation a laboratory set up was built. The main gas mixture consisted of CO, CO2, H2, H2O and N2 with the possibility to add gas or water-soluble contaminants, like H2S, NH3 and HCl, in low concentration (0–3 dm3 m−3). The set up can be operated up to 2 MPa pressure at 200–600 °C and run un-attendant for 100 h or more. For the second part of the work a catalytic probe was developed that allowed exposure of the catalyst by inserting the probe into the flowing gas from gasified biomass.

    The catalyst deactivates by two different causes. The initial deactivation is caused by the growth of the crystals in the active phase (magnetite) and the higher crystallinity the lower specific surface area. The second deactivation is caused by the presence of catalytic poisons in the gas, such as H2S, NH3 and chloride that block the active surface.

    The catalyst subjected to sulphur poisoning shows decreased but stable activity. The activity shows strong decrease for the ammonia and HCl poisoned catalysts. It seems important to investigate the levels of these compounds before putting a FeCr based shift step in industrial operation. The activity also decreased after the catalysts had been exposed to gas from gasified biomass. The exposed catalysts are not re-activated by time on stream in the laboratory set up, which indicates that the decrease in CO2-ratio must be attributed to irreversible poisoning from compounds present in the gas from the gasifier.

    It is most likely that the FeCr catalyst is suitable to be used in a high temperature shift step, for industrial production of synthesis gas from gasified biomass if sulphur is the only poison needed to be taken into account. The ammonia should be decomposed in the previous catalytic reformer step but the levels of volatile chloride in the gas at the shift step position are not known.

  • 34.
    Elled, Anna-Lena
    et al.
    University of Borås, School of Engineering.
    Davidsson, K.O.
    Åmand, L.E.
    Sewage sludge as a deposit inhibitor when co-fired with high potassium fuels2010In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 34, no 11, p. 1546-1554Article in journal (Refereed)
    Abstract [en]

    The objective of this work is to survey the fate of potassium in the gas phase of a fluidised bed boiler and gain deeper understanding of the involved mechanisms during co-firing of municipal sewage sludge with biomass containing high amounts of potassium and chlorine. The results show that formation of alkali chlorides in the flue gas and corrosive deposits on heat transfer surfaces can be controlled by addition of municipal sewage sludge even though the fuel is highly contaminated with chlorine. The beneficial effects are partly due to the content of sulphur in the sludge, partly to the properties of the sludge ash. The sludge ash consists of both crystalline and amorphous phases. It contains silica, aluminium, calcium, iron and phosphorus which all are involved in the capture of potassium. (c) 2010 Elsevier Ltd. All rights reserved.

  • 35.
    Endalew, Abebe K.
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Kiros, Yohannes
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Zanzi, Rolando
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Technology.
    Inorganic heterogeneous catalysts for biodiesel production from vegetable oils2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no 9, p. 3787-3809Article, review/survey (Refereed)
    Abstract [en]

    Biofuels are renewable solutions to replace the ever dwindling energy reserves and environmentally pollutant fossil liquid fuels when they are produced from low cost sustainable feedstocks. Biodiesel is mainly produced from vegetable oils or animal fats by the method of transesterification reaction using catalysts. Homogeneous catalysts are conventionally used for biodiesel production. Unfortunately, homogeneous catalysts are associated with problems which might increase the cost of production due to separation steps and emission of waste water. Inorganic heterogeneous catalysts are potentially low cost and can solve many of the problems encountered in homogeneous catalysts. Many solid acid and base inorganic catalysts have been studied for the transesterification of various vegetables oils. The work of many researchers on the development of active, tolerant to water and free fatty acids (FFA), as well as stable inorganic catalysts for biodiesel production from vegetable oils are reviewed and discussed.

  • 36.
    Ericsson, Karin
    et al.
    Environmental and Energy Systems Studies, Department of Technology and Society, Lund University, Lund, Sweden.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    The introduction and expansion of biomass use in Swedish district heating systems2016In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 94, p. 57-65Article in journal (Refereed)
    Abstract [en]

    District heating satisfies about 60% of the heat demand in Swedish buildings. Today, more than two thirds of the heat supply to the district heating systems is based on biomass and waste, and biomass alone accounts for about half of the heat supply. The purpose of this paper is to present the Swedish experiences of introducing and expanding the use of biomass in the district heating systems and to identify the main drivers behind this development. Our five research questions and the corresponding conclusions consider the driving forces from energy policy tools and local initiatives, the biomass prices, the established infrastructures in forestry and district heating, the technology paths for biomass conversion, and finally the future challenge of competing uses of biomass. © 2016 The Authors

  • 37.
    Frodeson, Stefan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Henriksson, Gunnar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Effects of moisture content during densification of biomass pellets, focusing on polysaccharide substances2019In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 122, p. 322-330Article in journal (Refereed)
    Abstract [en]

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

  • 38. Gabra, M.
    et al.
    Ohman, M.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Kjellstrom, B.
    Alkali retention/separation during bagasse gasification: A comparison between a fluidised bed and a cyclone gasifier2001In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, no 6, p. 461-476Article in journal (Refereed)
    Abstract [en]

    Biomass fuelled integrated gasification/gas turbines (BIG/GTs) have been found to be one of the most promising technologies to maximise electricity output in the sugar industry. However, biomass fuels contain alkali metals (Na and K) which may be released during the gasification processes and cause deleterious effects on the downstream hardware (e.g. the blades of gas turbines). Much research has therefore been focused on different kinds of gas cleaning. Most of these projects are using a fluidised bed gasifier and includes extensive gas cleaning which leads to a high capital investment. Increasing alkali retention/separation during the gasification may lead to improved producer gas quality and reduced costs for gas cleaning. However, very little quantitative information is available about the actual potential of this effect. In the present work, comparative bench-scale tests of bagasse gasification were therefore run in an isothermal fluidised bed gasifier and in a cyclone gasifier to evaluate which gasification process is most attractive as regards alkali retention/separation, and to try to elucidate the mechanisms responsible for the retention. The alkali retention in the fluidised bed gasifier was found to be in the range of 12-4% whereas in the cyclone gasifier the alkali separation was found to be about 70%. No significant coating of the fluidised bed's bed material particles could be observed. The SEM/EDS and the elemental maps of the bed material show that a non-sticky ash matrix consisting of mainly Si, Al and K were distributed in a solid form separated from the particles of bed material. This indicates the formation of a high temperature melting potassium containing silicate phase, which is continuously scavenged and lost from the bed through elutriation. © 2001 Elsevier Science Ltd. All rights reserved.

  • 39. Gabra, M.
    et al.
    Pettersson, Esbjörn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Backman, Rainier
    Kjellstrom, B.
    Evaluation of cyclone gasifier performance for gasification of sugar cane residue: Part 1: Gasification of bagasse2001In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, no 5, p. 351-369Article in journal (Refereed)
    Abstract [en]

    A method for avoiding excessive amount of alkali compounds and carryover particles in producer gas from gasification of sugar cane residue has been studied and evaluated. The cane sugar residue is gasified in a two-stage combustor at atmospheric pressure, where the first stage is a cyclone gasifier. The cyclone works as particle separator as well. This paper covers the results obtained for gasification of bagasse. Bagasse powder was injected into the cyclone with air and steam as transport medium. The gasification tests were made with two feeding rates, 39 and 52 kg/h. Seven experiments were conducted with the equivalence ratio being varied. The heating values of the producer gas are sufficient for stable gas turbine combustion. About 60-70% of the alkali input with fuel was separated from the producer gas in the cyclone. However the total alkali contents of the producer gas was found to be higher than in ABB Stal PFBC gas turbines and at least an order of magnitude higher than what is required by most gas turbine manufacturers for operation of a gas turbine. The carryover particles concentrations in the producer gas were found to be in the range of that for PFBC gas turbines, but higher than what is required by most gas turbine manufacturers for operation of a gas turbine. Samples studied with scanning electronic microscope give indication that most of the carryover particles are below 10 μm in size. Fly ash-melting tests have not shown any major ash melting up to 1200°C, but it was found that some of the particles entrained with producer gas were partially melted. Integrated experiments with a gas turbine need to be done for accurate evaluation of the possibilities to use the producer gas from the gasification of bagasse to run a gas turbine without problems of hard deposits and corrosion on the turbine blades. In part 2 of this two-part paper the results from cane trash gasification tests are reported. © 2001 Published by Elsevier Science Ltd.

  • 40. Gabra, M.
    et al.
    Pettersson, Esbjörn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Backman, Rainier
    Kjellstrom, B.
    Evaluation of cyclone gasifier performance for gasification of sugar cane residue: Part 2: Gasification of cane trash2001In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, no 5, p. 371-380Article in journal (Refereed)
    Abstract [en]

    In Part 1 of this two-part paper, results from gasification of bagasse in a cyclone gasifier have been reported. In this paper results from gasification of cane trash in the same cyclone gasifier are presented. The cane trash powder is injected into the cyclone with air as transport medium. The gasification tests were made with two feeding rates, 39 and 46 kg/h at two equivalence ratios of 0.25 and 0.20 and the gasification temperature ranging from 820°C to 850°C. It was found that the heating value of the producer gas is in the range of 4.5-4.8 MJ/Nm3(dry gas), which is sufficient for stable gas turbine combustion. Significant alkali separation has been achieved in the cyclone stage. However, the alkali levels and carryover particle concentrations in the producer gas were found to be higher than allowable in a gas turbine. Despite high ash melting temperatures found by the TGA-DTA, deposition problems cannot be excluded since some carryover panicles in the producer gas seem to have been melted and since some gasification of K and Na compounds is indicated. As an overall assessment, cane trash appears as a more problematic fuel than bagasse for this application. Integrated experiments with a gas turbine need to be done for accurate evaluation of the possibilities to use the producer gas from the gasification of cane trash to run a gas turbine without problems of hard deposits and corrosion on the turbine blades. © 2001 Published by Elsevier Science Ltd.

  • 41.
    Gabra, Mohamed
    et al.
    Luleå tekniska universitet.
    Kjellström, Björn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Salman, H.
    Luleå tekniska universitet.
    Development of a sugar cane residue feeding system for a cyclone gasifier1998In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 15, no 2, p. 143-153Article in journal (Refereed)
    Abstract [en]

    For the smooth and continuous operation of a cyclone gasifier, the fuel must be fed continuously and without interruption or large fluctuations. A feeding system for bagasse/cane trash powder was therefore designed, built and tested. It consisted of a feeding bin with four feeder screws in the bottom which deliver the fuel to two downcomers from which the fuel is injected by steam into the gasifier. During the first tests, the low bulk density and cohesive characteristics of a crushed bagasse/cane trash powder were found to cause an accumulation of the fuel in the feeding system, creating difficulties for the flow into the gasifier. In addition, once the flow of the crushed bagasse/cane trash powder is interrupted by a build-up in the downcomer channels, the crushed bagasse/cane trash powder becomes progressively compacted into a dense structure, resulting in blockage of the discharge. It was found possible to eliminate this problem by changing the shape of the slivers of the crushed bagasse/cane trash powder to render them more homogeneous. This was achieved by pelletizing the crushed bagasse or cane trash before grinding it to powder.

  • 42.
    Gabra, Mohamed
    et al.
    Energy Technology Centre, Piteå.
    Nordin, Anders
    Avdelningen för oorganisk kemi, Umeå universitet.
    Öhman, Marcus
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Kjellström, Björn
    Alkali retention/separation during bagasse gasification: a comparison between a fluidised bed and a cyclone gasifier2001In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, no 6, p. 461-476Article in journal (Refereed)
    Abstract [en]

    Biomass fuelled integrated gasification/gas turbines (BIG/GTs) have been found to be one of the most promising technologies to maximise electricity output in the sugar industry. However, biomass fuels contain alkali metals (Na and K) which may be released during the gasification processes and cause deleterious effects on the downstream hardware (e.g. the blades of gas turbines). Much research has therefore been focused on different kinds of gas cleaning. Most of these projects are using a fluidised bed gasifier and includes extensive gas cleaning which leads to a high capital investment. Increasing alkali retention/separation during the gasification may lead to improved producer gas quality and reduced costs for gas cleaning. However, very little quantitative information is available about the actual potential of this effect. In the present work, comparative bench-scale tests of bagasse gasification were therefore run in an isothermal fluidised bed gasifier and in a cyclone gasifier to evaluate which gasification process is most attractive as regards alkali retention/separation, and to try to elucidate the mechanisms responsible for the retention. The alkali retention in the fluidised bed gasifier was found to be in the range of 12-4% whereas in the cyclone gasifier the alkali separation was found to be about 70%. No significant coating of the fluidised bed's bed material particles could be observed. The SEM/EDS and the elemental maps of the bed material show that a non-sticky ash matrix consisting of mainly Si, Al and K were distributed in a solid form separated from the particles of bed material. This indicates the formation of a high temperature melting potassium containing silicate phase, which is continuously scavenged and lost from the bed through elutriation.

  • 43.
    Gabra, Mohamed
    et al.
    Luleå tekniska universitet.
    Pettersson, Esbjörn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Backman, Rainer
    Energy Technology Centre in Piteå, Division of Chemical Engineering, Åbo Akademi University.
    Kjellström, Björn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Evaluation of cyclone gasifier performance for gasification of sugar cane residue. Part 1: gasification of bagasse2001In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, no 5, p. 351-369Article in journal (Refereed)
    Abstract [en]

    A method for avoiding excessive amount of alkali compounds and carryover particles in producer gas from gasification of sugar cane residue has been studied and evaluated. The cane sugar residue is gasified in a two-stage combustor at atmospheric pressure, where the first stage is a cyclone gasifier. The cyclone works as particle separator as well. This paper covers the results obtained for gasification of bagasse. Bagasse powder was injected into the cyclone with air and steam as transport medium. The gasification tests were made with two feeding rates, 39 and 52 kg/h. Seven experiments were conducted with the equivalence ratio being varied. The heating values of the producer gas are sufficient for stable gas turbine combustion. About 60-70% of the alkali input with fuel was separated from the producer gas in the cyclone. However the total alkali contents of the producer gas was found to be higher than in ABB Stal PFBC gas turbines and at least an order of magnitude higher than what is required by most gas turbine manufacturers for operation of a gas turbine. The carryover particles concentrations in the producer gas were found to be in the range of that for PFBC gas turbines, but higher than what is required by most gas turbine manufacturers for operation of a gas turbine. Samples studied with scanning electronic microscope give indication that most of the carryover particles are below 10 μm in size. Fly ash-melting tests have not shown any major ash melting up to 1200°C, but it was found that some of the particles entrained with producer gas were partially melted. Integrated experiments with a gas turbine need to be done for accurate evaluation of the possibilities to use the producer gas from the gasification of bagasse to run a gas turbine without problems of hard deposits and corrosion on the turbine blades. In part 2 of this two-part paper the results from cane trash gasification tests are reported.

  • 44.
    Gabra, Mohamed
    et al.
    Luleå tekniska universitet.
    Pettersson, Esbjörn
    Backman, Rainer
    Energy Technology Centre in Piteå, Division of Chemical Engineering, Åbo Akademi University.
    Kjellström, Björn
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Evaluation of cyclone gasifier performance for gasification of sugar cane residue. Part 2: gasification of cane trash2001In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, no 5, p. 371-380Article in journal (Refereed)
    Abstract [en]

    In Part 1 of this two-part paper, results from gasification of bagasse in a cyclone gasifier have been reported. In this paper results from gasification of cane trash in the same cyclone gasifier are presented. The cane trash powder is injected into the cyclone with air as transport medium. The gasification tests were made with two feeding rates, 39 and 46 kg/h at two equivalence ratios of 0.25 and 0.20 and the gasification temperature ranging from 820°C to 850°C. It was found that the heating value of the producer gas is in the range of 4.5-4.8 MJ/Nm3(dry gas), which is sufficient for stable gas turbine combustion. Significant alkali separation has been achieved in the cyclone stage. However, the alkali levels and carryover particle concentrations in the producer gas were found to be higher than allowable in a gas turbine. Despite high ash melting temperatures found by the TGA-DTA, deposition problems cannot be excluded since some carryover particles in the producer gas seem to have been melted and since some gasification of K and Na compounds is indicated. As an overall assessment, cane trash appears as a more problematic fuel than bagasse for this application. Integrated experiments with a gas turbine need to be done for accurate evaluation of the possibilities to use the producer gas from the gasification of cane trash to run a gas turbine without problems of hard deposits and corrosion on the turbine blades.

  • 45.
    Galanopoulos, Christos
    et al.
    Bremen Univ, Inst Environm Sci & Technol, D-28359 Bremen, Germany..
    Yan, Jinying
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering. Vattenfall AB, R&D, SE-16992 Stockholm, Sweden.
    Li, Hailong
    Malardalen Univ, SE-72123 Vasteras, Sweden..
    Liu, Longcheng
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Impacts of acidic gas components on combustion of contaminated biomass fuels2018In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 111, p. 263-277Article in journal (Refereed)
    Abstract [en]

    The formation of high concentrations of acid gases; in combustion with large variations in fuel qualities, represents a major challenge for energy production from contaminated biomass fuels. This paper provides a comprehensive evaluation of the effects of acid gas formation and retention in the combustion of recycled wood fuels. A model has been developed based on the chemical reactions involved and empirical correlations from plant monitoring and testing. The model has been used to study the behaviour of acidic gas components in critical stages of a bubbling fluidised bed boiler process. Results indicate that the variation in type of fuel contamination is the most important issue to deal with in the combustion of recycled wood fuels. Peaks in the flue gas chlorine concentrations cannot be suppressed easily by conventional flue gas cleaning measures. Upon applying ammonium sulphate dosing for the protection of chlorine induced corrosions, it is sometimes difficult to maintain the required S/Cl ratio when large variations of fuel chlorine occur. Moreover, a high level of chlorine in the fuel can also indirectly affect the emission control of sulphur dioxide because it would require an increased level of ammonium sulphate decomposition, which results in a high level of SO2 in flue gas. The study also shows a beneficial effect of the recirculation of quench water from the flue gas condenser to the boiler. It offers opportunities for the optimisation of flue gas cleaning and flue gas condensation, for improving the efficiencies of water and wastewater treatment, as well as for emission reduction with a sustainable way.

  • 46.
    Galanopoulos, Christos
    et al.
    Bremen Univ, Inst Environm Sci & Technol, D-28359 Bremen, Germany..
    Yan, Jinying
    KTH Royal Inst Technol, Chem Engn, SE-10044 Stockholm, Sweden.;Vattenfall AB, R&D, SE-16992 Stockholm, Sweden..
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Liu, Longcheng
    KTH Royal Inst Technol, Chem Engn, SE-10044 Stockholm, Sweden..
    Impacts of acidic gas components on combustion of contaminated biomass fuels2018In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 111, p. 263-277Article in journal (Refereed)
    Abstract [en]

    The formation of high concentrations of acid gases; in combustion with large variations in fuel qualities, represents a major challenge for energy production from contaminated biomass fuels. This paper provides a comprehensive evaluation of the effects of acid gas formation and retention in the combustion of recycled wood fuels. A model has been developed based on the chemical reactions involved and empirical correlations from plant monitoring and testing. The model has been used to study the behaviour of acidic gas components in critical stages of a bubbling fluidised bed boiler process. Results indicate that the variation in type of fuel contamination is the most important issue to deal with in the combustion of recycled wood fuels. Peaks in the flue gas chlorine concentrations cannot be suppressed easily by conventional flue gas cleaning measures. Upon applying ammonium sulphate dosing for the protection of chlorine induced corrosions, it is sometimes difficult to maintain the required S/Cl ratio when large variations of fuel chlorine occur. Moreover, a high level of chlorine in the fuel can also indirectly affect the emission control of sulphur dioxide because it would require an increased level of ammonium sulphate decomposition, which results in a high level of SO2 in flue gas. The study also shows a beneficial effect of the recirculation of quench water from the flue gas condenser to the boiler. It offers opportunities for the optimisation of flue gas cleaning and flue gas condensation, for improving the efficiencies of water and wastewater treatment, as well as for emission reduction with a sustainable way.

  • 47.
    Gosens, Jorrit
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energi och Bioekonomi, Systemanalys. Chalmers University of Technology, Sweden; Chinese Academy of Sciences, China.
    Biopower from direct firing of crop and forestry residues in China: A review of developments and investment outlook2015In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 73, p. 110-123Article in journal (Refereed)
    Abstract [en]

    This paper reviews developments in the direct-fired biomass power sector and provides an up to date investment outlook by calculating the Net Present Value of new investments, and the appropriate level of Feed-in-Tariff needed to stimulate future investment. An overview is provided of support policies, historical growth in installations, and main market players. A number of data sources is combined to build a database with detailed information of individual biopower projects. This data is used to describe technological and market trends, which are used in a cash flow model to calculate the NPV of a typical project. The NPV for new projects is estimated to be negative, and investment should be expected to stall without proper policy intervention. Increasing fuel prices, local competition over biomass fuel resources, lower than expected operational performance and a downturn in carbon markets have deteriorated the investment outlook. In order to ensure reasonable profitability, the Feed-In-Tariff should be increased, from the current level of 90.9 € MWh−1, to between 97 and 105 € MWh−1. Where possible, government organizations should help organize demand for the supply of heat. Local rural energy bureaus may help organize supply networks for biomass fuels throughout the country, in order to reduce seasonal and local fuel scarcity and price fluctuations.

  • 48. Goshadrou, Amir
    et al.
    Karimi, Keikhosro
    University of Borås, School of Engineering.
    Taherzadeh, Mohammad J.
    University of Borås, School of Engineering.
    Ethanol and biogas production from birch by NMMO pretreatment2013In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 49, p. 95-101Article in journal (Refereed)
    Abstract [en]

    Birch wood was pretreated with N-methylmorpholine-N-oxide (NMMO or NMO) followed by enzymatic hydrolysis and fermentation to ethanol or digestion to biogas. The pretreatments were carried out with NMMO (wNMMO ¼ 85%) at 130 C for 3 h, and the effects of drying after the pretreatment were investigated. Enzymatic hydrolysis of the untreated wood resulted in 8%e10% of theoretical glucose yield after 4 days hydrolysis, while the NMMO pretreatment improved this yield to 91%. Consequently, ethanol production yield from NMMO-pretreated materials resulted in around 9-fold improvement compared to the untreated wood. On the other hand, drying of the pretreated wood had a negative impact and decreased the yield of enzymatic hydrolysis by 4%e10%. Digestion of the untreated wood with thermophilic bacteria resulted in maximum methane yield of 158 cm3 g 1 of VS in 30 days, while the NMMO pretreatment improved the methane yield up to 232 cm3 g 1 of VS (80% of the theoretical biogas yield) in just 9 days.

  • 49.
    Gullberg, Tomas
    et al.
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    Johansson, Jerry
    Dalarna University, School of Technology and Business Studies, Business Administration and Management.
    A method for integrated extraction of logging residues and soil scarification on a small scale2006In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 30, no 12, p. 1035-1042Article in journal (Refereed)
    Abstract [en]

    A new method for integrated haulage of logging residues and soil scarification on a small-scale has been evaluated. The base machine was a farm tractor to which a grapple loader trailer was attached. The grapple loader had an attachment on the grapple used for the integrated recovery of forest energy from logging residues and soil scarification. The machine was in this case, when hauling the logging residues fresh, also used for hauling round wood. It may even be used for, e.g. spreading wood ashes (only simulated). Conventional machine systems with special machines for all four types of work result in very high fixed costs for moving, etc. which makes cost unacceptable for many small sites. Effective time per dry ton of logging residues was 28.4min in the integrated method, of which soil scarification was 14.3min. Average load size was about 1.3ton dry matter (about 2.9m3 solid). The soil scarification plots covered 12% of the surface. Cost calculations show that the integration of several activities results in substantially lower costs for small harvesting sites. For sites of about 1.5ha the cost is about the same as for conventional machines. The studied method creates new possibilities for self-employed forest owners to do the work themselves and, in case of lower personal cost and no moving cost, reduce cost further.

  • 50.
    Gunnarsson, Carina
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Vågström, Lena
    RISE, SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Hansson, P.-A.
    Logistics for forage harvest to biogas production: Timeliness, capacities and costs in a Swedish case study2008In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 32, no 12, p. 1263-1273Article in journal (Refereed)
    Abstract [en]

    Production of biogas from energy crops of agricultural origin is regarded as a promising alternative to decrease dependence on non-renewable energy sources. A model was built to evaluate the handling system comprising harvest, transport and ensiling of forage intended for production of CH4-enriched biogas for vehicle fuel. The model was applied to a full-scale plant in Sweden producing biogas from organic household waste and forage. Timeliness, capacity and harvesting costs were studied by varying transport system design, transport distance, field size and dry matter (DM) yield. Matching harvest and transport capacity is essential in minimising the time required for harvesting and the resultant costs. However, this study showed that keeping the harvest and transport capacity sufficiently high to avoid idle time did not necessarily result in the lowest costs. By adapting the transport system, it was possible to reduce costs by 30% when the average transport distance was decreased from 17 to 8.5 km. The study showed that with forage for biogas production, it was optimal to harvest later than the normal dates for harvesting forage for milk production, since the lower biogas production per kg DM was compensated for by higher DM yield. As long as the harvest started on the days calculated as being optimal with respect to the value of the harvest, timeliness costs made up less than 4% of total costs depending on the transport system chosen. When the start of harvest deviated from the optimal, timeliness costs increased substantially. Delayed harvest had even larger impact on the total harvest costs. © 2008 Elsevier Ltd. All rights reserved.

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