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  • 1.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Aluminium i betong - Litteraturstudie och experimentella försök2012Report (Refereed)
    Abstract [sv]

    I dagens byggprojekt används en mängd olika material för att bygga konstruktioner. Det förekommer att komponenter av aluminium gjuts in i betong vilket medför en risk att täckskiktet spricker p.g.a. korrosionsprodukternas stora volym. Därför är det viktigt att klargöra vilka korrosionsegenskaper aluminium har ingjuten i betong.

  • 2.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Atmosfäriska korrosionsegenskaper för rostfritt stål med olika ytstruktur2011Report (Refereed)
    Abstract [sv]

    Generellt sett så har rostfria stål en hög korrosionsresistens i atmosfärisk miljö p.g.a. den mycket tunna oxidfilmen på ytan, en film som fungerar som en barriär och försvårar initieringen av en korrosionsprocess på stålets yta. Dock så kan rostfria stål få svåra gropfrätningsangrepp i vissa aggressiva atmosfärer där t.ex. klorider och SO2 finns närvarande. Olika ytstrukturer kan ge ytan olika egenskaper som vätbarhet, ytråhet och ytsammansättning. En yta som har hög vätbarhet har en tjockare fuktfilm på ytan jämfört med en yta som har låg vätbarhet. Det är i fuktfilmen på ytan som korrosionsprocesserna sker, aggressiva partiklar och gaser kan tas upp i fuktfilmen från atmosfären och öka korrosionshastigheten. Ytråheten påverkar både vätbarhet och hur mycket partiklar som fastnar på en yta, därmed påverkar ytråheten korrosionshastigheten. Ytsammansättning anger vilka och hur mycket det finns av ett ämne i den skyddande oxidfilmen, ämnen som kan ha betydelse för hur lätt korrosion uppstår, t.ex. så kan olika sulfider fungera som initieringsyta för korrosionsangrepp. I litteraturen har det dragits olika slutsatser om vilken ytegenskap som har störst betydelse för korrosionens omfattning. Vissa studier säger att ytråheten har störst betydelse medan andra säger att ytsammansättningen har störst betydelse. Särskilt låglegerade ferritiska rostfria stål kan få svår gropfrätning i aggressiva miljöer och då har typen av ytstruktur liten betydelse för hur stora korrosionsangreppen blir. För de mer legerade austenitiska stålen kan typen av ytstruktur ha stor betydelse för storleken på korrosionsangrepp. Höglegerade stål som innehåller molybden har generellt sett små korrosionsangrepp och typen av ytstruktur har liten betydelse för korrosionsangreppens omfattning. Sammantaget tycks det dock vara så att ytråheten ändå har relativt stor inverkan på korrosionsresistensen, dock har relativt få studier genomförts där ytråheten verkligen mätts.

  • 3.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Rostfritt stål i betong med hög fukt och kloridhalt - Provningsmetod för rostfritt stål i betong: Delrapport IV2011Report (Refereed)
    Abstract [sv]

    För betongkonstruktioner som är exponerade i aggressiva miljöer kan korrosionsskador uppstå som kräver kostsamma reparationer. Aggressiva miljöer kan t.ex. vara konstruktioner i kontakt med havsvatten där klorider kan transporteras genom betongskiktet fram till armeringen och där orsakar korrosionsskador. För att förhindra vissa korrosionsskador kan armering av kolstål (som är det vanligaste armeringsmaterialet) bytas ut mot armering i rostfritt stål. Idag finns en mängd olika rostfria stål, med olika korrosionsegenskaper, tillgängliga på marknaden och det är därför viktigt att kunna klassificera korrosionshärdigheten för dessa stål. I en tidigare litteraturstudie ”Elektrokemiska metoder för utvärdering av armeringskorrosion samt kritisk kloridjonkoncentration för rostfritt stål i betong” [1] så undersöktes vad som har rapporterats i litteraturen om provningsmetoder för att undersöka korrosionshärdigheten för rostfritt stål i betong. Det framgick av litteraturstudien att en potentiostatisk metod med polarisering till +200 mV kan vara lämplig. I denna studie har en liknande potentiostatisk metod tillämpats och utvärderats. Provkropparna placerades i ett vattenbad där temperaturen ökade med 5°C per 14 dagar från lägst 20°C till maximalt 40°C. Två austenitiska och tre duplexa stål har undersökts och resultaten visar att stålen EN 1.4301 (304), EN 1.4162 (2101), EN 1.4436 (316) fick korrosionsangrepp vid 4 vikt-% Cl per cementvikt när temperaturen på vattenbadet var mellan 20 och 30°C. Det mer legerade duplexa stålet EN 1.4362 (2304) fick korrosionsangrepp vid 6 vikt-% Cl per cementvikt vid en temperatur på 35°C. Det högst legerade stålet EN 1.4462 (2205) fick inga korrosionsangrepp vid10 vikt-% Cl per cementvikt som var den högsta kloridkoncentrationen.

  • 4.
    Ahlström, Johan
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Jafri, Yawer
    Luleå University of Technology, Sweden.
    Wetterlund, Elisabeth
    Luleå University of Technology, Sweden; International Institute for Applied Systems Analysis, Austria.
    Furusjö, Erik
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy. Luleå University of Technology, Sweden.
    Sustainable aviation fuels – Options for negative emissions and high carbon efficiency2023In: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 125, article id 103886Article in journal (Refereed)
    Abstract [en]

    Mitigating the climate impact from aviation remains one of the tougher challenges in adapting society to fulfill stated climate targets. Long-range aviation cannot be electrified for the foreseeable future and the effects of combusting fuel at high altitude increase the climate impact compared to emissions of green-house gasses only, which further limits the range of sustainable fuel alternatives. We investigate seven different pathways for producing aviation biofuels coupled with either bio-energy carbon capture and storage (BECCS), or bio-energy carbon capture and utilization (BECCU). Both options allow for increased efficiency regarding utilization of feedstock carbon. Our analysis uses process-level carbon- and energy balances, with carbon efficiency, climate impact and levelized cost of production (LCOP) as primary performance indicators. The results show that CCS can achieve a negative carbon footprint for four out of the seven pathways, at a lower cost of GHG reduction than the base process option. Conversely, as a consequence of the electricity-intensive CO2 upgrading process, the CCU option shows less encouraging results with higher production costs, carbon footprints and costs of GHG reduction. Overall, pathways with large amounts of vented CO2, e.g., gasification of black liquor or bark, as well as fermentation of forest residues, reach a low GHG reduction cost for the CCS option. These are also pathways with a larger feedstock and corresponding production potential. Our results enable a differentiated comparison of the suitability of various alternatives for BECCS or BECCU in combination with aviation biofuel production. By quantifying the relative strengths and weaknesses of BECCS and BECCU and by highlighting cost, climate and carbon-efficient pathways, these results can be a source of support for both policymakers and the industry. © 2023 The Author(s)

  • 5.
    Ahlström, Johan
    et al.
    Chalmers University of Technology, Sweden.
    Pettersson, Karin
    RISE - Research Institutes of Sweden, Built Environment, Energy and Circular Economy. Chalmers University of Technology, Sweden.
    Wetterlund, Elisabeth
    Luleå University of Technology, Sweden.
    Harvey, Simon
    Chalmers University of Technology, Sweden.
    Value chains for integrated production of liquefied bio-SNG at sawmill sites – Techno-economic and carbon footprint evaluation2017In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 206, p. 1590-1608Article in journal (Refereed)
    Abstract [en]

    Industry's increasing demand for liquefied natural gas could be met in the future by liquefied methane produced from biomass feedstock (LBG - liquefied biogas). This study presents results from an investigation of value chains for integrated production of LBG at a generic sawmill site, based on gasification of sawmill waste streams and forest residues. The objective was to investigate the cost for, as well as the carbon footprint reduction associated with, production and use of LBG as a fuel. Five different LBG plant sizes were investigated in combination with three different sawmill sizes. The resulting cases differ regarding biomass feedstock composition, biomass transportation distances, LBG plant sizes, how efficiently the excess heat from the LBG plant is used, and LBG distribution distances. Pinch technology was used to quantify the heat integration opportunities and to design the process steam network. The results show that efficient use of energy within the integrated process has the largest impact on the performance of the value chain in terms of carbon footprint. The fuel production cost are mainly determined by the investment cost of the plant, as well as feedstock transportation costs, which mainly affects larger plants. Production costs are shown to range from 68 to 156 EUR/MW hfuel and the carbon footprint ranges from 175 to 250 kg GHG-eq/MW hnet biomass assuming that the product is used to substitute fossil LNG fuel. The results indicate that process integration of an indirect biomass gasifier for LBG production is an effective way for a sawmill to utilize its by-products. Integration of this type of biorefinery can be done in such a way that the plant can still cover its heating needs whilst expanding its product portfolio in a competitive way, both from a carbon footprint and cost perspective. The results also indicate that the gains associated with efficient heat integration are important to achieve an efficient value chain.

  • 6.
    Ahlström, Johan
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Tidblad, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Sandberg, Bertil
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Wadsö, Lars
    Lund University, Sweden.
    Galvanic corrosion properties of steel in water saturated concrete2015In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 66, no 1, p. 67-75Article in journal (Refereed)
    Abstract [en]

    Aluminum-based sacrificial anodes were installed to reinforced concrete to stop ongoing corrosion in cooling water tunnels in a Swedish nuclear power plant. The steel rebars were also unintentionally connected to stainless steel water pumps. Therefore, the consumption rate of the sacrificial anodes was higher than predicted. An experimental and a field study were performed to assess if the steel rebar suffer from galvanic corrosion and if the stainless steel pumps are responsible alone for the high consumption rate. It was found from the experimental study that there is an increased risk of galvanic corrosion for steel rebar when the corrosion potential is raised to -200mV (SCE) for samples with 1% CL- by mass of cement and -500mV (SCE) for samples with 2% Cl- by mass of cement. The experimental results were compared with the corrosion potential measured in the cooling water tunnel where sacri ficial anodes were in use and not mounted at all. The cooling water tunnel without sacrificial anodes had generally more anodic corrosion potentials compared to the tunnel with anodes. The tunnel with anodes had also more anodic potentials closer to the stainless steel pumps than further away which means that the rebar is affected by the stainless steel pumps. However, the measured corrosion potentials in the tunnels were not as anodic as the potentials needed for high galvanic current measured in the experimental study.

  • 7.
    Ahlström, Johan
    et al.
    RISE, Swerea, KIMAB.
    Tidblad, Johan
    RISE, Swerea, KIMAB. RISE - Research Institutes of Sweden (2017-2019), Materials and Production, KIMAB.
    Sederholm, Bror
    RISE, Swerea, KIMAB.
    Wadsö, L.
    Lund University, Sweden.
    Influence of chloride and moisture content on steel rebar corrosion in concrete2016In: Materials and corrosion - Werkstoffe und Korrosion, ISSN 0947-5117, E-ISSN 1521-4176, Vol. 67, no 10, p. 1049-1058Article in journal (Refereed)
    Abstract [en]

    Reinforced mortar samples were exposed in humidity chambers with different relative humidity or exposed in cyclic moisture conditions. The rebars were in an “as received” condition meaning that the preexisting oxide scale were intact. The lowest chloride concentration that initiated corrosion was 1% Cl− by mass of cement, corrosion was then observed for samples exposed at 97% relative humidity. It is suggested that the corrosion rate decreases when samples are exposed to a relative humidity lower than 97%. The results indicate that threshold levels should be evaluated at rather humid conditions (97%) despite the fact that the maximum corrosion rate at higher chloride levels is observed in the interval 91–94%. For samples exposed to cyclic moisture conditions, a lower chloride concentration was needed to initiate corrosion compared to samples exposed in static moisture conditions.

  • 8.
    Ahlström, Johan
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB. Chalmers University of Technology, Sweden.
    Tidblad, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Tang, Luping
    Chalmers University of Technology, Sweden.
    Sederholm, Bror
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Leijonmarck, Simon
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Electrochemical properties of oxide scale on steel exposed in saturated calcium hydroxide solutions with or without chlorides2018In: International Journal of Corrosion, ISSN 1687-9325, E-ISSN 1687-9333, Vol. 2018, article id 5623504Article in journal (Refereed)
    Abstract [en]

    The electrochemical properties of various iron oxide scales on steel exposed in saturated calcium hydroxide solutions were investigated. The iron oxide scales were manufactured by different heat treatments and grinding processes and characterized using X-ray diffraction and scanning electron microscope. The electrochemical properties of the scales were assessed by measuring the corrosion potential and using electrochemical impedance spectroscopy and potentiodynamic polarization curves. It was found that wustite and magnetite are less noble compared to hematite but are more effective as cathodic surfaces. The results show that the electrochemical properties of the mill scale can be an important contributing factor in the corrosion of steel in concrete.

  • 9.
    Andersson, Johan
    et al.
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Ahlström, Johan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Berg, Karin
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Olsson, Henrik
    Karlsson, Lars-Evert
    Wärtsilä Sweden AB. Sweden.
    Niinipuu, Mirva
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Pizzul, Leticia
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Biologisk metanisering av syngas från förgasning och pyrolys - lovande koncept mot implementering2024Report (Other academic)
    Abstract [en]

    Biological methanation of syngas from pyrolysis and gasification – promising concepts for implementation The need for increased biogas production is significant, and in the EU, there are plans for a substantial expansion in the coming years through the RePowerEU initiative. Part of the increase will come from the expansion of conventional digestion technology, where organic materials such as food waste, manure, and crop residues are used for biogas production. However, to meet the future increased demand, it is also necessary to utilize more difficult-to-digest substrates, such as biomass rich in lignocellulose, for biogas production. This could be forest residues such as branches and tops, sawdust, or bark. This type of substrates cannot be used in a conventional digestion process, and other technology chains are therefore required to convert such biomass into biomethane. This can be done by first converting the biomass into syngas through a thermochemical process such as gasification or pyrolysis. This is followed by a methanation process where the syngas is converted into biogas, and finally, the gas is upgraded to reach biomethane quality. These types of technology chains are not currently available on a commercial scale, but they have been demonstrated, for example, through the Gobigas project, where gasification was followed by catalytic methanation for biomethane production. As full-scale implementation of catalytic methanation of bio-syngas has not yet been achieved, thereis a need to develop alternative conversion technologies that can more cost-effectively achieve the methanation of woody biomass. One possible opportunity for to this is to apply biological methanation instead of a catalytic process. A biological process comes with several advantages, including a greater ability to handle contaminants, higher selectivity in the conversion of syngas, and operation at relatively low temperature and pressure, which simplifies material selection and reactor design. RISE, together with its partners, are developing a concept based on biological methanation of syngas. This project has examined the biological process's ability to handle contaminants in syngas through continuous experiments in carrier-filled trickle bed reactors with an active volume of 5 liters. The process's ability to handle and break down contaminants is an important parameter that can affect and simplify the design of the gas cleaning that occurs after gasification or pyrolysis. Another aspect of the project has been to put the experimental results into context at the concept and system level. Different production techniques for syngas have been mapped out, which could be combined with biological methanation. Based on the mapping, three types of plants have been selected for more detailed analyses of techno-economics, carbon footprint, and opportunities for increased carbon efficiency. The methanation experiments lasted for 552 days, and overall, it was a stable process with high turnover of syngas and high methane production over a long time. There have been some operational disturbances, mainly related to the supply of gas to the process (i.e. delivery of gas cylinders). However, biochemical inhibition or disturbances have been rare, demonstrating a high robustness for biological methanation of syngas. The breakdown of contaminants has been excellent in the process, with levels decreasing below the detection limit. At the same time, as contaminants have been continuously added to the process, microbiology has been able to maintain high turnover of hydrogen and carbon monoxide to methane. The specific methane production was high both during the reference period without contaminants and during the experimental periods with added contaminants. During long periods, the specific methane production has been around 4 L CH4/Lbed volume /day, which is about 4 times higher than our previously achieved results. The transition to thermophilic temperature and using carriers with higher effective surface area has contributed to this increase. During the project, three types of plants have been selected for more detailed analysis: 1) Gasification with Cortus process, which generates a relatively clean syngas with minimal purification needs before biological methanation. There is no need for co-location with a heating plant, but it is an advantage if there is access to the district heating network to sell waste heat. 2) Gasification with Bioshares' concept, where the gasifier is integrated into a larger cogeneration plant and where the produced syngas is purified with an RME-scrubber before biological methanation. Co-location with a larger cogeneration plant provides interesting synergies and integration opportunities, but also sets the boundaries for where the plants can be located. 3) Slow pyrolysis according to Envigas' concept, where the primary product is biochar and where the produced syngas is seen as a by-product. The syngas contains some impurities but generally requires no other purification than cooling to the right temperature (condensing out tars) before being added to biological methanation. This type of plant differs from plant types 1-2 in that the syngas formed is not the primary product, and the syngas has a relatively low energy value compared to the others. Syngas from plant types 2 and 3 contains some hydrocarbons (C1-C3) that are considered inert over the methanation step and therefore do not negatively affect the process. This means that heavier hydrocarbons do not need to be removed upstream, which would likely have been required with catalytic methanation. This leads to a higher system efficiency, and the need for reactor capacity for biological methanation decreases since there is less gas to be processed (more of the end-product consists of hydrocarbons already formed during the thermochemical conversion upstream). For all plant types, downstream of the methanation step, there is a need for further gas purification and upgrading. During the upgrading step carbon dioxide is separated to reach the product specification required by the end user. If long distance distribution is required a final process step consisting of a liquefaction plant for the production of liquid biogas (LBG) can be added to the concept. As another option, the systems can be supplemented with treatment of the carbon dioxide flow out of the upgrading plant, where the flow is processed by drying, compression, and cooling to produce liquid carbon dioxide. For plant type 2, where benzene is present in the syngas, this gas is expected to be separated with relatively high precision in the system and thereby generate a small flow of liquid benzene as a side product. The carbon dioxide emissions for the final product LBG are in the range of 1.6 to 2.6 gCO2-eq/MJLBG, which compares favorably to other types of second-generation biofuels. Compared to fossil gas, the reduction in greenhouse gas emissions is 96-97%. The carbon efficiency of the systems can be significantly increased if excess carbon dioxide is utilized either through BECCS or BECCU. If the carbon dioxide stream from the upgrading plant is processed into liquid carbon dioxide, the production cost is estimated to be 187-204 SEK/ton. If the product is to be sent to permanent storage the cost for transportation and storage would need to be added to estimate total cost of BECCS, but this is out of scope for the current project.. Assuming that BECCS is applied and that the entire carbon sink is allocated to the final product LBG, this will result in negative emissions in the range of -35 to -104 gCO2-eq/MJLBG. An alternative is to utilize excess carbon dioxide directly in the methanation process by boosting incoming gas with extra hydrogen. Hydrogen and carbon dioxide are then converted by methanogens, which generates extra methane. Since the addition of extra hydrogen is assumed to come from electrolysis, the additional methane production can likely be classified as electrofuel, so-called e-methane. The techno-economic evaluation results in a production cost ranging from 740 to 1300 SEK/MWhLBG, including all sensitivity scenarios. The lower price scenarios include a lower investment cost, which can be assumed to represent cases with public investment support. Overall, a large part of the scenarios are considered to be within the range of what can be considered market relevant production costs. This leads to the conclusion that there is techno-economic potential at this stage to justify continued development of concepts based on biological methanation of syngas. With scaling up and continued development in the right direction, the concepts may eventually lead to cost-effective utilization of forest residues for the production of biomethane at a commercially relevant scale. The next step in the development is scaling up to pilot scale, which will take place during 2023-2025 through an EU-funded project and will be carried out by RISE, Wärtsilä, Cortus and Swedish Gas Association. A pilot plant for biological methanation will then be operated with syngas from Cortus' gasifier in Höganäs.

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  • 10.
    Hansson, Julia
    et al.
    IVL Swedish Environmental Research Institute, Sweden; Chalmers University of Technology, Sweden.
    Ahlström, Johan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Furusjö, Erik
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Lundgren, Joakim
    Luleå University of Technology, Sweden.
    Nojpanya, Pavinee
    IVL Swedish Environmental Research Institute, Sweden.
    COSTS FOR REDUCING GHG EMISSIONS FROM ROAD AND AIR TRANSPORT WITH BIOFUELS AND ELECTROFUELS2023In: European Biomass Conference and Exhibition Proceedings, ETA-Florence Renewable Energies , 2023, p. 368-372Conference paper (Refereed)
    Abstract [en]

    The potential future role of different biofuels, hydrogen, and so-called electrofuels/power-to-X (produced by electricity, water, and carbon dioxide, CO2) in different transportation sectors remains uncertain. The CO2 abatement cost, i.e., the cost for reducing a certain amount of greenhouse gas (GHG) emissions, is central from a societal and business perspective, the latter specifically in the case of an emission reduction obligation system (like in Germany and Sweden). The abatement cost of a specific fuel value chain depends on the production cost and the GHG reduction provided by the fuel. This paper analyses the CO2 abatement costs for different types of biofuels, biomass-based jet fuels and electrofuels for road transport and aviation, relevant for the Swedish and EU context. Since most assessed alternative fuel pathways achieve substantial GHG emission reduction compared to fossil fuels, the fuel production cost is, in general, more important to achieve a low CO2 abatement cost. The estimated CO2 abatement cost ranges from -0.37 to 4.03 SEK/kgCO2 equivalent. Fuels based on waste feedstock, have a relatively low CO2 abatement cost. Fuel pathways based on electricity or electricity and biomass have relatively high CO2 abatement cost. The CO2 abatement cost for lignocellulosic based pathways generally ends up in between. 

  • 11.
    Jafri, Y.
    et al.
    Luleå University of Technology, Sweden.
    Ahlström, Johan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Furusjö, Erik
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy. Luleå University of Technology, Sweden.
    Harvey, S.
    Chalmers University of Technology, Sweden.
    Pettersson, Karin
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Svensson, E.
    CIT Industriell Energy AB, Sweden.
    Wetterlund, E.
    Luleå University of Technology, Sweden; IIASA, Austria.
    Double Yields and Negative Emissions?: Resource, Climate and Cost Efficiencies in Biofuels With Carbon Capture, Storage and Utilization2022In: Frontiers in Energy Research, E-ISSN 2296-598X, Vol. 10, article id 797529Article in journal (Refereed)
    Abstract [en]

    As fossil-reliant industries turn to sustainable biomass for energy and material supply, the competition for biogenic carbon is expected to intensify. Using process level carbon and energy balance models, this paper shows how the capture of residual CO2 in conjunction with either permanent storage (CCS) or biofuel production (CCU) benefits fourteen largely residue-based biofuel production pathways. With a few noteworthy exceptions, most pathways have low carbon utilization efficiencies (30–40%) without CCS/U. CCS can double these numbers and deliver negative emission biofuels with GHG footprints below −50 g CO2 eq./MJ for several pathways. Compared to CCS with no revenue from CO2 sequestration, CCU can offer the same efficiency gains at roughly two-third the biofuel production cost (e.g., 99 EUR/MWh vs. 162 EUR/MWh) but the GHG reduction relative to fossil fuels is significantly smaller (18 g CO2 eq./MJ vs. −99 g CO2 eq./MJ). From a combined carbon, cost and climate perspective, although commercial pathways deliver the cheapest biofuels, it is the emerging pathways that provide large-scale carbon-efficient GHG reductions. There is thus some tension between alternatives that are societally best and those that are economically most interesting for investors. Biofuel pathways vent CO2 in both concentrated and dilute streams Capturing both provides the best environomic outcomes. Existing pathways that can deliver low-cost GHG reductions but generate relatively small quantities of CO2 are unlikely to be able to finance the transport infrastructure required for transformative bio-CCS deployment. CCS and CCU are accordingly important tools for simultaneously reducing biogenic carbon wastage and GHG emissions, but to unlock their full benefits in a cost-effective manner, emerging biofuel technology based on the gasification and hydrotreatment of forest residues need to be commercially deployed imminently. Copyright © 2022 Jafri, Ahlström, Furusjö, Harvey, Pettersson, Svensson and Wetterlund.

  • 12.
    Leijon, Gunnar
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    In-situ hydrogen charging of OFP copper under creep2014Report (Refereed)
    Abstract [en]

    A method to creep test copper intended for nuclear waste disposal during continuous hydrogen charging has been developed and tested. The method has strived to reproduce results published by a Finnish research group. Temperature, stress, strain and other conditions are similar in the two studies. The results show that the method is capable of introducing large amounts of hydrogen into the copper but, in contrast to the Finnish results, no cracks has been observed.

  • 13.
    Lundblad, Anders Olof
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Nordin Fürdös, Axel
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Nilsson, Karin
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Pettersson, Karin
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Axelsson, Lovisa
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Ahlström, Johan
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Vätgas som alternativ för skogsindustrins transporter– en jämförande studie (H2Timmer)2022Report (Other academic)
    Abstract [sv]

    Detta förstudieprojekt har visat att vätgasdrift för timmerlastbilar ger något högre men ändå liknande kilometerkostnad som ren batteridrift, men snabbare tankning och längre körsträcka, vilket ger större flexibilitet för åkaren. Även biodrivmedel kan vara ett konkurrenskraftigt alternativ. Skogsindustrin är en av Sveriges största transportanvändare. För timmertransporter är lastbil det klart viktigaste transportslaget och skogsindustrins transporter motsvarar ca 17 % av Sveriges transporterade gods på väg. Ett alternativ för omställning av skogsindustrins transporter till fossilfrihet är förnybar vätgas, som kan produceras genom elektrolys med förnybar el. Precis som el ger vätgas inte upphov till några lokala emissioner vid användningen. Produktion av vätgas kan potentiellt ha synergier för skogsindustrins massabruk, som behov av syrgas och tillgång till överskottsel. Projektet har undersökt vätgas som alternativ för skogsindustrins transporter. Hela värdekedjan, inklusive produktion, komprimering, lagring, och användning inkluderas i analysen som beaktar kostnader, energieffektivitet och växthusgasutsläpp ur ett ”well-to wheel”-perspektiv. Studien inkluderar jämförelser med andra möjliga alternativ för att ställa om transporterna till fossilfrihet så som elektrifiering och biodrivmedel. Projektet har gett resultat som kommer att ligga till grund för en mer detaljerad projekteringsstudie inför ett framtida demonstrations- och pilotprojekt. Studien som finansierats av Trafikverket genom TripleF har genomförts av RISE tillsammans med 6 skogsindustribolag, tre företag från fordonsbranschen och två systemintegratörer med fokus på vätgas. Medverkande företag och organisationer: Sveaskog, SmurfitKappa, Metsä Group, Holmen, StoraEnso, BillerudKorsnäs, AB Volvo, Volvo Penta, Volvo CE, Nilsson Energy, Euromekanik, Energiforsk, Skogsindustrierna.

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  • 14.
    Lundblad, Anders Olof
    et al.
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Nordin Fürdös, Axel
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Persson, Karin
    RISE Research Institutes of Sweden, Safety and Transport, Electrification and Reliability.
    Pettersson, Karin
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Axelsson, Lovisa
    RISE Research Institutes of Sweden, Built Environment, System Transition and Service Innovation.
    Ahlström, Johan
    RISE Research Institutes of Sweden, Bioeconomy and Health, Biorefinery and Energy.
    Vätgas som alternativ för skogsindustrins transporter– en jämförande studie (H2Timmer): Exekutiv sammanfattning2022Report (Other academic)
    Abstract [sv]

    Detta förstudieprojekt har undersökt vätgas som alternativ för skogsindustrins transporter. Hela värdekedjan, inklusive produktion, komprimering, lagring, och användning inkluderas i analysen som beaktar kostnader, energieffektivitet och växthusgasutsläpp ur ett ”well-to wheel”-perspektiv. Projektet har genomförts av RISE tillsammans med följande företag och organisationer: Sveaskog, SmurfitKappa, Metsä Group, Holmen, StoraEnso, BillerudKorsnäs, AB Volvo, Volvo Penta, Volvo CE, Nilsson Energy, Euromekanik, Energiforsk, Skogsindustrierna.

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  • 15.
    Sederholm, Bror
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Rostfria ståls korrosionshärdighet och galvaniska inverkan på kolstål i betong med hög fukt- och kloridhalt2013Report (Refereed)
    Abstract [sv]

    Föreliggande rapport avslutar FoU-projektet - Rostfria ståls korrosionsegenskaper i betong med en hög fukt- och kloridhalt. I rapporten ingår resultat från fyra delrapporter som tidigare publicerats inom projektet. I rapporten ingår även nya resultat från två års utomhusexponering i havsvatten och i stadsatmosfär av betongingjutna provstänger av rostfritt stål (kamstänger) av stålkvaliteten EN 1.4301, 1.4436, 1.4162, 1.4362 och 1.4462 samt provstänger av kolstål ihopkopplade med rostfria provstänger för att undersöka risken för galvanisk korrosion på kolstålet. Betongblock av tre olika betongkvaliteter (OPC C45/55, CEM I, PFA C32/40, CEM IIB-V och GGBFS C32/40, CEM IIIA) ingår i undersökningarna. Vid utomhusexponering i stadsatmosfär innehåller betongblocken före exponering 2-10 mass-% klorider per bindemedelsvikt och har ett täckande betongskikt av 15 mm och ett vbt av 0,45. Vid utomhusexponering i havsvatten innehåller samtliga betongblock före exponering en total kloridhalt av 3 % klorider per bindemedelsvikt och ett täckande betongskikt av 15 mm och vbt 0,45. Samtliga utförda undersökningarna (utomhus och på laboratorium) visar att rostfri stålarmering av stålkvaliteten EN 1.4301, 1.4436, 1.4162, 1.4362 och 1.4462 har betydligt bättre förmåga att motstå korrosionsangrepp i en kloridhaltig betong jämfört med ett vanligt kolstål. Förmågan hos rostfri armering att motstå korrosionsangrepp i en kloridhaltig betong beror framförallt av halten legeringsämnen som finns i det rostfria stålet. De legeringsämnen som har stor betydelse för det rostfria stålets förmåga att motstå korrosionsangrepp är framförallt krom, nickel, molybden och kväve. Det framgår vidare att korrosionshärdigheten hos fem olika rostfria stålkvaliteter som ingått i laboratorieundersökningarna ökar enligt följande ordning: (sämst) EN 1.4301 < EN 1.4162 < EN 1.4436 < EN 1.4362 < EN 1.4462 (bäst). Vid en total kloridhalt av 3 % per bindemedelvikt i betongblock med olika bindemedel (OPC C45/55, CEM I, PFA C32/40, CEM IIB-V och GGBFS C32/40, CEM IIIA) som exponerats delvis nedsänkta i havsvatten i två år kunde inga för ögat synliga, korrosionsangrepp konstateras på rostfria provstänger av stålkvaliteten EN 1.4301, 1.4436, 1.4162, 1.4362 och 1.4462.

  • 16.
    Sederholm, Bror
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB.
    Trädgårdh, Jan
    Korrosionsprovning av injekterade bergbultar och av provstänger av stål ingjutna i betongblock - resultat av fem års exponering i Äspötunneln2014Report (Refereed)
    Abstract [sv]

    Denna undersökning, som initierats av Svensk Kärnbränslehantering AB (SKB) och som utförts av Swerea KIMAB AB och CBI Betonginstitutet, omfattar fem års korrosionsprovning i Äspötunneln. Undersökningen omfattar sex betongblock (tre block med låg-pH betong och tre block med konventionell anläggningsbetong) med ingjutna provstänger av kolstål och tre stycken fyra meter långa bergbultar ingjutna i låg-pH bultbruk i Äspötunnelns tak och vägg. Betongblocken med ingjutna provstänger av kolstål har tidigare utvärderats efter 18 månader exponering, Vogt/2009, Ahlström & Sederholm/2010 och Bodén & Pettersson/ 2011. Beträffande de ingjutna bergbultarna har ingen utvärdering tidigare gjorts. Resultaten från undersökningarna sammanfattas nedan. Provstänger av stål ingjutna i betongblock • Provstänger av stål i de båda betongtyperna utan klorider visade försumbara korrosionshastigheter och bedömdes vara i passivt tillstånd. Det bör dock påpekas att ett fåtal lokala korrosionsangrepp kunde observeras på ändytorna på de provstänger som exponerats i låg-pH betong. • Provstänger av stål i låg-pH betong där betongblocken förexponerats i kloridlösning visade försumbara korrosionshastigheter och bedömdes vara i passivt tillstånd. För provstänger av stål ingjutna i en anläggningsbetong, betongblock förexponerade i en kloridlösning, uppmättes en korrosionshastighet av ca 13 μm/år efter fem års exponering. Orsaken till skillnaden är att kloridhalten varit låg vid stålytan under exponeringen på grund av långsam kloridtransport i den täta låg-pH betongen. • På provstänger av stål ingjutna i låg-pH betong med ingjutna klorider uppmättes en korrosionshastighet av ca 13 μm/år och i anläggningsbetong med ingjutna klorider en korrosionshastighet av ca 2,3 μm/år, efter fem års exponering. Sammanfattningsvis kan sägas att korrosionshastigheten hos provstänger i betongblock med ingjutna klorider i en låg-pH betong är betydligt högre, 5-6 gånger högre, jämfört med korrosionshastigheten hos provstänger av stål som varit ingjutna i betongblock med anläggningsbetong, under fem års exponering i Äspötunneln. _x0001_ Bergbultar injekterade med bultbruk (låg-pH pasta och låg-pH bruk) • Inga korrosionsangrepp kunde konstateras på någon av de undersökta bergbultarna som varit injekterade i låg-pH bultbruk. • Inga krympsprickor kunde konstateras i något av de undersökta bultbruken. • Vidhäftningen mellan bergbultarna och de båda bultbruken var god. • pH-värdet hos bultbruken varierade mellan 11,3 och 11,9. • Ca/Si-kvoten i bultbruken visade att ingen urlakning skett hos bultbruken under fem års exponering. Sammanfattningsvis kan sägas att de tre undersökta bergbultarna är i mycket god kondition efter att ha varit ingjutna i låg-pH bultbruk med och utan ballast i ca 5 år i Äspötunnelns bergvägg och innertak. Eftersom ingen urlakning av bultbruken skett under exponeringstiden kan det konstateras att inget flödande vatten från sprickor i berget varit i kontakt med bultbruken och bergbultarna. Både syrehalten och fukthalten har varit låg under försökets gång.

  • 17.
    Sederholm, Bror
    et al.
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB, Corrosion protection of building structures.
    Trägårdh, Jan
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Ahlström, Johan
    RISE - Research Institutes of Sweden, Materials and Production, KIMAB, Corrosion protection of building structures.
    Boubitsas, Dimitrios
    RISE - Research Institutes of Sweden, Built Environment, CBI Swedish Cement and Concrete Research Institute.
    Luping, Tang
    Chalmers University of Technology, Sweden.
    Ny provningsmetodik för bestämning av bindemedlets korrosionsskyddande förmåga i betong2018Report (Other academic)
    Abstract [sv]

    Denna rapport omfattar slutrapporteringen av forskningsprojektet - Ny provningsmetodik för bedömning av bindemedlets korrosionsskyddande förmåga i betong – Underlag till LCA och livslängdsbedömning. I rapporten redovisas resultat från elektrokemiska undersökningar utförda på laboratorium och korrosionsprovningar i fält. Undersökningarna har genomförts av Swerea KIMAB, RISE CBI Betonginstitutet (väst och öst) samt Chalmers. Projektets mål har varit att genom en nationell samling av expertis ta fram en ny provningsmetodik som på ett enkelt och tillämpbart sätt ska utvärdera olika bindemedels korrosionsskyddande förmåga i betong. I denna undersökning har framför allt tiden till initiering av korrosion (gropfrätning) från det att kloriderna har nått stålytan och tills gropfrätning har initieras på stålytan undersökts. Tre olika accelererade elektrokemiska mätmetoder har använts och jämförts:

     Potentiostatisk mätmetod

     Potentiodynamisk mätmetod

     Galvanostatisk mätmetod

    Den framtagna provningsmetodiken med framställning av provkroppar har visat sig fungera väl. För att minska spridningen är det emellertid viktigt att använda en homogen och rengjord stålyta utan glödskal. Glödskalet avlägsnas lämpligast genom slipning eftersom betning kan bygga upp ett passivskikt på stålytan. För att undvika att betongrester fastnar på stålytan ska släta provstänger användas.

    Sammanfattningsvis kan sägas att resultaten från laboratorie- och fältmätningarna samt analyser av bindemedlens korrosionskänslighet genom TG- och XRD-analyser visade att denna kombination av mätningar ger ett bra verktyg att bedöma den korrosionsskyddande förmågan hos olika bindemedel. En sammanställning av rangordningen för bindemedlens korrosionsskyddande förmåga redovisas i tabellen nedan.

    Den korrosionsskyddande förmågan hos de undersökta bindemedlen rangordnas från en sammanvägning av de olika provningsmetoderna:

     bra < 1,5 och

     1,5 ≥mindre bra ≤2,5 och

     dåligt > 2,5.

    Som rangordningen visar i tabellen så har bindemedel med slagg och portlandcement med hög C 3A en bra korrosionsskyddande förmåga. Detta beror till största delen på kapaciteten att bilda Friedels salt från monosulfat under härdningsprocessen. Bindemedel som har en låg korrosionsskyddande förmåga har ett lågt C3A-innehåll och en inblandning av flygaska och/eller silika. Det medför dessutom en utspädningseffekt på förmågan att bilda Friedels salt.

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  • 18.
    Zavalis, Tommy
    et al.
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Ström, Mats
    Volvo Car Corporation, Sweden.
    Persson, Dan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Wendel, Erik
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Ahlström, Johan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Törne, Karin
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Taxén, Claes
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Rendahl, Bo
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Voltaire, Joakim
    Scania CV AB, Sweden.
    Eriksson, Katarina
    Gestamp HardTech AB, Sweden.
    Thierry, Dominique
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Tidblad, Johan
    RISE Research Institutes of Sweden, Materials and Production, Corrosion.
    Mechanistic Model with Empirical Pitting Onset Approach for Detailed and Efficient Virtual Analysis of Atmospheric Bimetallic Corrosion2023In: Materials, E-ISSN 1996-1944, Vol. 16, no 3, article id 923Article in journal (Refereed)
    Abstract [en]

    A mechanistic model of atmospheric bimetallic corrosion with a simplified empirical approach to the onset of localized corrosion attacks is presented. The model was built for a typical bimetallic sample containing aluminum alloy 1050 and stainless steel 316L sheets. A strategy was developed that allowed the model to be calibrated against the measured galvanic current, geometrical corrosion attack properties, and corrosion products. The pitting-onset simplification sets all pits to be formed at a position near the nobler metal and treated all pits as being of the same shape and size. The position was based on the location of the highest pitting events and the pit attributes on an average of the deepest pits. For 5 h exposure at controlled RH (85%, 91%, and 97%) and salt load (86 μg NaCl/cm2), the model was shown to be promising: both for analysis of local bimetallic corrosion chemistry, such as pH and corrosion products, and for efficient assessment of pitting damage by computing a single largest pit depth. Parametric studies indicated that the pitting-onset approximation deviated the most at the beginning of exposure and when RH was below 91%. © 2023 by the authors.

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