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  • 1.
    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, Biovetenskap och material, Jordbruk och livsmedel.
    Schnürer, Anna
    SLU Swedish University of Agricultural Sciences, Sweden.
    Production efficiency of Swedish farm-scale biogas plants2017Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 97, s. 27-37Artikel i tidskrift (Refereegranskat)
    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.

  • 2. 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 production2014Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 64, s. 256-268Artikel i tidskrift (Refereegranskat)
    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.

  • 3.
    Arrhenius, Karine
    et al.
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Yaghooby, Haleh
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Rosell, Lars
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Büker, Oliver
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    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, BTEX2017Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 105, s. 127-135Artikel i tidskrift (Refereegranskat)
    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.

  • 4.
    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, Bioekonomi. RISE., Innventia.
    von Schenck, A.
    ÅF AB, Sweden.
    Provision of pulpwood and short rotation eucalyptus in Bahia, Brazil: Environmental impacts based on lifecycle assessment methodology2017Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 105, s. 41-50Artikel i tidskrift (Refereegranskat)
    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.

  • 5. 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 emissions2005Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 29, nr 4, s. 258-268Artikel i tidskrift (Refereegranskat)
    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.

  • 6. 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 gasifier2001Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, nr 6, s. 461-476Artikel i tidskrift (Refereegranskat)
    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.

  • 7. 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 bagasse2001Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, nr 5, s. 351-369Artikel i tidskrift (Refereegranskat)
    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.

  • 8. 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 trash2001Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 21, nr 5, s. 371-380Artikel i tidskrift (Refereegranskat)
    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.

  • 9.
    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 outlook2015Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 73, s. 110-123Artikel i tidskrift (Refereegranskat)
    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.

  • 10.
    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 study2008Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 32, nr 12, s. 1263-1273Artikel i tidskrift (Refereegranskat)
    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.

  • 11. Heggset, Ellinor B
    et al.
    Syverud, Kristin
    RISE., Innventia, PFI – Paper and Fiber Research Institute.
    Øyaas, Karin
    RISE., Innventia, PFI – Paper and Fiber Research Institute.
    Novel pretreatment pathways for dissolution of lignocellulosic biomass based on ionic liquid and low temperature alkaline treatment2016Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 93, s. 194-200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pretreatment, fractionation and hydrolysis remains costly and challenging process steps in biochemical conversion of softwoods. Here, ionic liquid pretreatment using 1-ethyl-3-methylimidazolium acetate (EMIM-OAc) at high temperature (100 °C, 6 h) and alkali based (NaOH/urea) pretreatment at sub-zero temperature (−18 °C, 24 h) were compared and combined in studies of Norway Spruce biomass deconstruction. Both treatments significantly improved the enzymatic digestibility of the biomass. EMIM-OAc gave higher glucan than mannan digestibility, indicating a more pronounced effect on the cellulose polymer than on the hemicellulose polymer. In contrast, low temperature alkali pretreatment using NaOH or NaOH + urea gave a more pronounced effect on mannan than on glucan digestibility. By combining the two methods the total monosugar yield after enzymatic hydrolysis was improved by 20–50% as compared to using ionic liquid or alkali based pretreatment alone. Lignin dissolution was low for both methods under the conditions studied.

  • 12. Kimming, M.
    et al.
    Sundberg, C.
    Nordberg, Åke
    RISE., SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Baky, Andras
    RISE., SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Bernesson, S.
    Norén, Olle
    RISE., SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Hansson, P.-A.
    Biomass from agriculture in small-scale combined heat and power plants: A comparative life cycle assessment2011Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, nr 4, s. 1572-1581Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biomass produced on farm land is a renewable fuel that can prove suitable for small-scale combined heat and power (CHP) plants in rural areas. However, it can still be questioned if biomass-based energy generation is a good environmental choice with regards to the impact on greenhouse gas emissions, and if there are negative consequences of using of agricultural land for other purposes than food production. In this study, a simplified life cycle assessment (LCA) was conducted over four scenarios for supply of the entire demand of power and heat of a rural village. Three of the scenarios are based on utilization of biomass in 100 kW (e) combined heat and power (CHP) systems and the fourth is based on fossil fuel in a large-scale plant. The biomass systems analyzed were based on 1) biogas production with ley as substrate and the biogas combusted in a microturbine, 2) gasification of willow chips and the product gas combusted in an IC-engine and 3) combustion of willow chips for a Stirling engine. The two first scenarios also require a straw boiler. The results show that the biomass-based scenarios reduce greenhouse gas emissions considerably compared to the scenario based on fossil fuel, but have higher acidifying emissions. Scenario 1 has by far the best performance with respect to global warming potential and the advantage of utilizing a byproduct and thus not occupying extra land. Scenario 2 and 3 require less primary energy and less fossil energy input than 1, but set-aside land for willow production must be available. The low electric efficiency of scenario 3 makes it an unsuitable option. © 2011 Elsevier Ltd.

  • 13.
    Leijenhorst, Evert J.
    et al.
    BTG Biomass Technology Group BV, Netherlands.
    Assink, Daan
    BTG Biomass Technology Group BV, Netherlands.
    van de Beld, Bert
    BTG Biomass Technology Group BV, Netherlands.
    Weiland, Fredrik
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Wiinikka, Henrik
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Carlsson, Per
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Öhrman, Olov G. W.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Entrained flow gasification of straw- and wood-derived pyrolysis oil in a pressurized oxygen blown gasifier2015Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 79, s. 166-176Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fast pyrolysis oil can be used as a feedstock for syngas production. This approach can have certain advantages over direct biomass gasification. Pilot scale tests were performed to investigate the route from biomass via fast pyrolysis and entrained flow gasification to syngas. Wheat straw and clean pine wood were used as feedstocks; both were converted into homogeneous pyrolysis oils with very similar properties using in-situ water removal. These pyrolysis oils were subsequently gasified in a pressurized, oxygen blown entrained flow gasifier using a thermal load of 0.4 MW. At a pressure of 0.4 MPa and a lambda value of 0.4, temperatures around 1250 °C were obtained. Syngas volume fractions of 46% CO, 30% H2 and 23% CO2 were obtained for both pyrolysis oils. 2% of CH4 remained in the product gas, along with 0.1% of both C2H2 and C2H4. Minor quantities of H2S (3 vs. 23) cm3 m−3, COS (22 vs. 94) cm3 m−3 and benzene (310 vs. 532) cm3 m−3 were measured for wood- and straw derived pyrolysis oils respectively. A continuous 2-day gasification run with wood derived pyrolysis oil demonstrated full steady state operation. The experimental results show that pyrolysis oils from different biomass feedstocks can be processed in the same gasifier, and issues with ash composition and melting behaviour of the feedstocks are avoided by applying fast pyrolysis pre-treatment.

  • 14.
    Mandova, H.
    et al.
    University of Leeds, UK; IIASA International Institute for Applied Systems Analysis, Austria.
    Leduc, S.
    IIASA International Institute for Applied Systems Analysis, Austria.
    Wang, C.
    RISE - Research Institutes of Sweden, Swerea, Swerea MEFOS AB. Åbo Akademi University, Finland.
    Wetterlund, E.
    IIASA International Institute for Applied Systems Analysis, Austria; Luleå University of Technology, Sweden.
    Patrizio, P.
    IIASA International Institute for Applied Systems Analysis, Austria.
    Gale, W.
    University of Leeds, UK.
    Kraxner, F.
    IIASA International Institute for Applied Systems Analysis, Austria.
    Possibilities for CO2 emission reduction using biomass in European integrated steel plants2018Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 115, s. 231-243Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Iron and steel plants producing steel via the blast furnace-basic oxygen furnace (BF-BOF) route constitute among the largest single point CO2 emitters within the European Union (EU). As the iron ore reduction process in the blast furnace is fully dependent on carbon mainly supplied by coal and coke, bioenergy is the only renewable that presents a possibility for their partial substitution. Using the BeWhere model, this work optimised the mobilization and use of biomass resources within the EU in order to identify the opportunities that bioenergy can bring to the 30 operating BF-BOF plants. The results demonstrate competition for the available biomass resources within existing industries and economically unappealing prices of the bio-based fuels. A carbon dioxide price of 60 € t−1 is required to substitute 20% of the CO2 emissions from the fossil fuels use, while a price of 140 € t−1 is needed to reach the maximum potential of 42%. The possibility to use organic wastes to produce hydrochar would not enhance the maximum emission reduction potential, but it would broaden the available feedstock during the low levels of substitution. The scope for bioenergy integration is different for each plant and so consideration of its deployment should be treated individually. Therefore, the EU-ETS (Emission Trading System) may not be the best policy tool for bioenergy as an emission reduction strategy for the iron and steel industry, as it does not differentiate between the opportunities across the different steel plants and creates additional costs for the already struggling European steel industry. © 2018 The Authors

  • 15. Natarajan, E.
    et al.
    Nordin, Anders
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Rao, A.N.
    Overview of combustion and gasification of rice husk in fluidized bed reactors1998Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 14, s. 533-546Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rice is cultivated in more than 75 countries in the world. The rice husk is the outer cover of the rice and on average it accounts for 20% of the paddy produced, on weight basis. The worldwide annual husk output is about 80 million tonnes with an annual energy potential of 1.2 x 10 9 GJ corresponding to a heating value of 15 MJ/kg. India alone generates about 22 million tonnes of rice husk per year. If an efficient method is available, the husk can be converted to a useful form of energy to meet the thermal and mechanical energy requirements of the rice mills themselves. This paper provides an overview of previous works on combustion and gasification of rice husk in atmospheric bubbling fluidized bed reactors and summarizes the state of the art knowledge. As the high ash content, low bulk density, poor flow characteristics and low ash melting point makes the other types of reactors like grate furnaces and downdraft gasifiers either inefficient or unsuitable for rice husk conversion to energy, the fluidized bed reactor seems to be the promising choice. The overview shows that the reported results are from only small bench or lab scale units. Although a combustion efficiency of about 800 can normally be attained; the reported values in the literature, which are more than 95%, seem to be in higher order. Combustion intensity of about 530 kg/h/m 2 is reported. It is also technically feasible to gasify rice husk in a fluidized bed reactor to yield combustible producer gas, even with sufficient heating value for application in internal combustion engines. A combustible gas with heating value of 4-6 MJ/Nm 3 at a rate of 2.8-4.6 MW(th)/m 2 seems to be possible. Only very little information is available on the pollutant emissions in combustion and tar emissions from gasification. The major conclusion is that the results reported in the literature are limited and vary widely, emphasizing the need for further research to establish suitable and optimum operating conditions for commercial implementations.The combustion and gasification of rice husks in atmospheric bubbling fluidized bed reactors are studied. The rice husks are gasified in the bed reactor to yield combustible producer gas, even with sufficient heating value for application in internal combustion engines. A combustible gas with heating value of 4-6 MJ/Nm 3 at a rate of 2.8-4.6 MW th/m 2 is possible.

  • 16.
    Nordberg, Åke
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, JTI Institutet för Jordbruks- och Miljöteknik.
    Edström, Mats
    Uusi-Penttila, M.
    Rasmuson, A.C.
    Selective desorption of carbon dioxide from sewage sludge for in-situ methane enrichment: Enrichment experiments in pilot scale2012Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 37, s. 196-204Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The application of in-situ methane enrichment for upgrading the biogas from anaerobic digestion to vehicle fuel or natural gas quality, has been studied in pilot scale and by computer simulation of the desorption step. Pilot plant experiments have been performed using a 19m 3 and 15m 3 continuously stirred tank reactor operating with municipal sewage sludge at mesophilic conditions connected respectively to a 90dm 3 and 140dm 3 external bubble column for selective desorption of CO 2. The results show that the CH 4 yield is unchanged during the experiments, and accordingly there is no evidence that the oxygen in the air used in the desorption of CO 2 has a negative impact on the CH 4 producing activity. The sludge recirculation system must be designed to avoid leakage of air into the digester, in order to maintain a low N 2 concentration in the biogas. At best, a biogas with a volume fraction of 87% CH 4 and φN2=2% was obtained. The CH 4 loss however amounted to 8%, which is unsatisfactory. The experimental results are compared with previous data in the literature and explanations are deducted for the difference in the performance. Computer simulations reveal that the sludge flow rate recirculated through the desorption column should be as low as possible to minimize the loss of CH 4. An increased air flow rate through the desorption column and an increased desorption column volume will promote the desorption of CO 2 and improve the ratio of CO 2 to CH 4 desorption. © 2011 Elsevier Ltd.

  • 17.
    Ohman, M.
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Boman, Christoffer
    Hedman, Henry
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Nordin, Anders
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Bostrom, D.
    Slagging tendencies of wood pellet ash during combustion in residential pellet burners2004Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 27, nr 6, s. 585-596Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ash related problems have more than occasionally been observed in pellet burners during the last years. These problems can lead to reduced accessibility of the combustion systems as well as bad publicity for the market. The objectives of the present work were to; (i) evaluate how different raw materials for pellets affect the accessibility of the existing burner equipment, (ii) determine which of the ash forming element(s) that could be responsible for the deposit/slagg formation and, (iii) estimate the critical slagging temperature for the different raw materials. Stored and fresh materials from sawdust, logging residues and bark were used as raw material in three different pellet burners. The results showed that the slagging properties were relatively sensitive to the variations in total ash content and ash forming elements of the fuel. It is therefore recommended that ash rich fuels like bark and logging residues should not be used in the existing residential pellet burners. Both fuel and burner type affected the amounts of ash deposit produced. The degree of sintering (i.e. the strength of the deposits) was mostly affected by the fuel composition. Subsequent controlled sintering test of the produced deposits/slags showed critical slagging temperatures of about 850-900°C for stored bark and about 1000°C for fresh bark and stored and fresh materials from sawdust and logging residues. The results further indicated that the Si-content in the fuel correlated (relatively) well to the sintering tendencies in the burners. Chemical equilibrium models were used to interpret the experimental findings, and good quantitative agreements between modelling and experimental results were generally obtained. © 2004 Elsevier Ltd. All rights reserved.

  • 18.
    Ohman, M.
    et al.
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Nordin, Anders
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Hedman, Henry
    Jirjis, R.
    Reasons for slagging during stemwood pellet combustion and some measures for prevention2004Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 27, nr 6, s. 597-605Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ash related problems have more than occasionally been observed in pellet burners during the last years. These problems lead to reduced accessibility of the appliances and also bad publicity for the pellet market. The objectives of the present work were therefore to: (i) determine the critical levels of the problematic ash components in stemwood pellets regarding slagging, (ii) document the variations of these problematic elements in the outgoing pellets from two pellet-mills during one operational season, (iii) determine how frequently these elements exceed the critical levels, (iv) determine how different sub-processes in the pelletising process (especially the dryer) effect the slagging properties of the pellet, and if possible (v) suggest some measures for prevention. A significant number of wood pellets reported to be problematic and problem-free, regarding slagging in ordinary residential pellet burners, were collected from the Swedish market. The ash compositions of these fuels were analysed and the results compiled in a database. Partial Least-Squares Discriminant Analysis (PLS-DA) and F-tests were used to statistically identify both the critical ash components and the critical levels of these components that separated the two reported classes. In addition, chemical equilibrium model calculations were used to interpret the findings. The variations of these elements in the in-going raw material and in the produced pellets were determined during one season in two pellet mills equipped with exhaust gas dryers. The results showed that the problematic wood-pellets had a significantly higher amount of Si, but also Al and Fe, in the fuel ash. The critical level of Si (given as SiO 2) was about 20-25 wt% of the fuel ash, i.e. pellets with levels in or over this range resulted in slagging problems in residential burners. This critical Si content was exceeded once and twice for the analysed samples in the two studied pellet mills. In one of the studied mills, this was because of contamination by sand of the raw material during storage and handling, and in the other mill the reason was found to be contamination of the raw material by elutriated particles from the dryer fuel. The major conclusion of the work is that both raw materials and drying fuels/processes should be carefully treated to avoid mineral contamination, and an additional cyclone separator could potentially also be used to improve the pellet quality. © 2004 Elsevier Ltd. All rights reserved.

  • 19.
    Sundberg, Peter
    et al.
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Energi och cirkulär ekonomi. Luleå University of Technology, Sweden.
    Hermansson, Sven
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Energi och cirkulär ekonomi. Södra Skogsägarna Ekonomisk Förening, Sweden.
    Tullin, Claes
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Energi och cirkulär ekonomi. Luleå University of Technology, Sweden.
    Öhman, Marcus
    Luleå University of Technology, Sweden.
    Traceability of bulk biomass: Application of radio frequency identification technology on a bulk pellet flow2018Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 118, s. 149-153Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Radio frequency identification (RFID) technology has been used since the 1950s in a wide range of applications. In the energy sector, there is a potential to use the technology to follow biomass fuels throughout a supply chain. In addition to logistic information, the RFID tags can be used to convey vital information of the fuel properties directly to the energy plant to be used at the moment of combustion. A detailed knowledge of the fuel composition at the moment it reaches the furnace can be used to improve energy efficiency, reduce emissions and limit problems with fouling and slagging. In this work, RFID technology was used in three separate trials to trace wood pellets, from the production site to the furnace. In the trials, RFID tags were added to batches of pellets containing 5% or 100% peat. In this way it was possible to follow the shift in pellet quality from standard pellets (100% wood) to the pellets containing the RFID tags by monitoring the change in flue gas composition. From the results it can be concluded that RFID tags indeed can be used to convey logistic information and thus information of fuel quality parameters throughout a supply chain for wood pellets. However, work on optimization is needed to design the RFID carrier properly to mix well with the pellets as illustrated in a separate trial. Finally, an economic estimate indicates that the marginal cost to implement a RFID system would be less than 1% of the total production cost of wood pellets.

  • 20.
    Wiinikka, Henrik
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Gebart, Rikard
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Energy Technology Center.
    Experimental investigations of the influence from different operating conditions on the particle emissions from a small-scale pellets combustor2004Ingår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 27, nr 6, s. 645-652Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The purpose of this study is to determine how different design parameters in an idealised small-scale combustor affect the emission of particulates in the flue gas and to provide insight that can be used for design optimisation. The design parameters are the primary air factor, the total air factor and the magnitude of swirling flow in the combustion chamber. Particles from the reactor were collected from two different sampling lines, one located in the combustion zone, just above the fuel bed, and the other in the flue stack after the reactor. The measurements show that this burner gives very low emissions of particulates and CO in the flue gas. Furthermore, the concentration of particles in the flue gas is uncoupled to the concentration of particles immediately above the fuel bed, probably as a result of a well-designed secondary air supply. The variable that had the strongest effect on the total particulate emission from the combustor was the total air factor. In order to understand the qualitative differences in the flow nature between different operating conditions, CFD simulations of the flow field were also performed. © 2004 Elsevier Ltd. All rights reserved.

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