RISE – Research Institutes of Sweden
Not a member yet
7718 research outputs found
Sort by
Quality of biogenic carbon dioxide stream from biogas plants including analytical method development
No full textThe capture, use and storage of biogenic CO2 from the biogas sector contributes to environmental benefits by reducing the overall greenhouse gas emissions. In several plants, CO2 separated in the biogas upgrading process is captured and processed. Depending on the composition, some level of purification is needed before the biogenic CO2 can be used, for example, in the food industry. In this article, we first present novel or adapted analytical methods which are both cost-effective and reliable to assess the purity of CO2 streams. These methods concern not only species that are currently regulated in different standards but also allows for an extensive overview of the overall gas composition. The methods are then applied to samples of CO2 stream collected from different biogas plants located in Sweden. Results from this campaign are presented together with some conclusions regarding the need to further purify the stream so the CO2 even fulfill the most stringent requirements such as those set by the food industry. The need for purification concerns only a few species: water, methane, oxygen, nitrogen (for all samples), and hydrogen sulfide (in two cases). VOCs found specifically when the plants digest food wastes may also require a purification step, however, only some of these compounds are currently regulated.Funder name: European Partnership on Metrology. Funder ID: 10.13039/100019599. Grant number: 21GRD06 MetCCUS. Funder name: European Metrology Programme for Innovation and Research. Grant number: 20IND10 Decarb</p
Energy Efficiency Potential of Second Homes Heated by Direct Electric Heating Located in Four Regions in Sweden
No full textEU countries have committed to taking national measures to reduce the average energy use of residential buildings by 16% by 2030 and 20–22% by 2035. Each country has decided how to achieve this and which buildings to focus on. However, certain categories of residential buildings, including historical buildings but also second homes, may be exempt from these obligations. In Sweden, second homes constitute a substantial part of the housing stock and contribute to energy use for heating and hot water of 2.79 TWh, of which 2.16 TWh is electricity. Even if the owners of second homes are not obliged to take energy efficiency measures, quite simple and inexpensive measures may contribute to substantial energy savings. In this study, simulations of energy use in 862 second homes heated with direct electric heating were carried out for five energy efficiency measures (additional attic insulation, new windows, air-to air heat pump and decreasing the temperature during absence to 10 and 5 °C). With the assumption that the 862 second homes are representative of the entire stock of electric-heated second homes in Sweden, the energy saving potential was estimated to be 1.17 TWh per year if all homes install heat pumps and 0.99 TWh and 1.30 TWh per year if all lower the temperature to 10 °C or 5 °C when the house is not used. This study has been conducted as part of the research project “Energieffektiviseringoch varsam renovering av fritidshus” P2022-00125 funded by Spara & Bevara, The SwedishEnergy Agency.</p
The use of simulations in economic cybersecurity decision-making
No full textThis paper presents an in-depth examination of the use of simulations in economic cybersecurity decision-making, highlighting the dual nature of their potential and the challenges they present. Drawing on examples from existing studies, we explore the role of simulations in generating new knowledge about probabilities and consequences in the cybersecurity domain, which is essential in understanding and managing risk and uncertainty. Additionally, we introduce the concepts of "bookkeeping"and "abstraction"within the context of simulations, discussing how they can sometimes fail and exploring the underlying reasons for their failures. This discussion leads us to suggest a framework of considerations for effectively utilizing simulations in cybersecurity. This framework is designed not as a rigid checklist but as a guide for critical thinking and evaluation, aiding users in assessing the suitability and reliability of a simulation model for a particular decision-making context. Future work should focus on applying this framework in real-world settings, continuously refining the use of simulations to ensure they remain effective and relevant in the dynamic field of cybersecurity. This work was supported by H2020-SU-DS02-2020, grant number101020259 (M.K.) and the Swedish Foundation for Strategic Research,grant number SM22-0057 (U.F.).</p
Sustainable production of bio-based epoxy resins using the phenolics produced via atmospheric ex-situ catalytic hydropyrolysis of biomass
No full textReplacement of fossil-based chemicals with their bio-based analogues is vital to reduce the fossil dependence and greenhouse gas emissions. Accordingly, production of bio-based epoxy resin is important for a sustainable development. The aim of this study was to introduce a potential technique for producing phenolic compounds from biomass followed by a synthesis of bio-based epoxy resin. Hence, atmospheric ex-situ catalytic hydropyrolysis of wood sawdust was performed using a Molybdenum on Aluminum oxide (Mo/Al2O3) catalyst in a continuous drop-tube pyrolyzer for a selective production of phenolic compounds. The phenolics were purified and concentrated by liquid–liquid extraction and used to synthesize bio-based epoxy resin. The results revealed that a mild catalytic hydrotreatment of the pyrolysis vapor using Mo/Al2O3 at 673 K improved the phenolics yield. The organic pyrolysis oil contained up to 41 wt% phenolics whereof 20 wt% were volatile. The properties of the synthesized bio-based diglycidyl ether of bisphenol A epoxy resin (pyroEP) was comparable to those of commercial epoxy resin. The glass transition temperature of 426 K and reaction energy of 324 kJ/kg confirmed the successful production of a high-performance, sustainable epoxy resin. This was funded by the Kamprad Foundation for Entrepreneurship, Research & Charity, Sweden, award no. 20200124.</p
Installationsintyg släcksystem
No full textGranskning utförd av RISE av tre installationer av släcksystem i fordon avsedda för användning i gruvor och undermarksanläggningar visar att placeringen av släcksystemens dysor eller munstycken kan skilja sig ganska mycket åt även i fordon av samma modell och utförande. Samtliga system hade vätskebaserat släckmedel .En jämförelse med certifierade släcksystem som har godkänd klassning enligt SBF 127:17 visar att de installerade släcksystem som granskats har hälften av det antal dysor som har använts vid provningar för att kunna släcka de testscenarier som krävs för att uppfylla klassning enligt SBF 127:17. De släcksystem som granskats i detta projekt har installerats innan SBF 127:17 utgavs. Att använda sig av ett förenklat installationsintyg där grundläggande information för det provade/ certifierade släcksystemet återfinns samt att de mest kända brandriskerna i fordonets motorrum har mitigerats genom släckdysornas placering kan vara ett rimligt sätt att höja nivån på installationen av släcksystemen samt för att uppfylla de krav på släcksystem och dokumentation som ställs i SBF 127:17. Förslag till installationsintyg som presenterats i TUSC RISE Rapport 2023:76 har reviderats utifrån de erfarenheter som gjorts under det arbetet som presenteras i denna rapport. Det reviderade förslaget på installationsintyg återfinns i bilaga 2.Hör ihop med följande två tidigare publikationer:https://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ari%3Adiva-67111https://urn.kb.se/resolve?urn=urn%3Anbn%3Ase%3Ari%3Adiva-52388</p
Modification of xylan in secondary walls alters cell wall biosynthesis and wood formation programs and improves saccharification
No full textWood of broad-leaf tree species is a valued source of renewable biomass for biorefinery and a target for genetic improvement efforts to reduce its recalcitrance. Glucuronoxylan (GX) plays a key role in recalcitrance through its interactions with cellulose and lignin. To reduce recalcitrance, we modified wood GX by expressing GH10 and GH11 endoxylanases from Aspergillus nidulans in hybrid aspen (Populus tremula L. × tremuloides Michx.) and targeting the enzymes to cell wall. The xylanases reduced tree height, modified cambial activity by increasing phloem and reducing xylem production, and reduced secondary wall deposition. Xylan molecular weight was decreased, and the spacing between acetyl and MeGlcA side chains was reduced in transgenic lines. The transgenic trees produced hypolignified xylem having thin secondary walls and deformed vessels. Glucose yields of enzymatic saccharification without pretreatment almost doubled indicating decreased recalcitrance. The transcriptomics, hormonomics and metabolomics data provided evidence for activation of cytokinin and ethylene signalling pathways, decrease in ABA levels, transcriptional suppression of lignification and a subset of secondary wall biosynthetic program, including xylan glucuronidation and acetylation machinery. Several candidate genes for perception of impairment in xylan integrity were detected. These candidates could provide a new target for uncoupling negative growth effects from reduced recalcitrance. In conclusion, our study supports the hypothesis that xylan modification generates intrinsic signals and evokes novel pathways regulating tree growth and secondary wall biosynthesis. This work was supported by the Knut and Alice Wallenberg(KAW) Foundation, the Swedish Governmental Agency forInnovation Systems (VINNOVA), Swedish Research Council,Kempestiftelserna, T4F, Bio4Energy and the SSF programValueTree RBP14-0011 to EJM. FV and PS acknowledge thefinancial support from the Swedish Research Council (ProjectGrant 2020-04720) to FV. MK was supported by The CzechScience Foundation (GACR) via 20-25948Y junior grant. </p
Verification of constrained multi-body motion in MoodyMarine
No full textMoodyMarine is a weakly nonlinear potential flow model for wave-body and mooring simulations with a graphical user interface. In this work we present the extension of the model to deal with constrained multi-body dynamics. By combining different translation and rotation constraints most joints can be modelled. As the constraints are imposed through springs and dampers in the explicit time-stepping algorithm, a slight manual tuning is required to make sure the bodies are constrained properly. Nevertheless, this tuning is shown not to influence the final results. In the paper we compare to existing test cases in literature as well as against experimental data. In all test cases there is a good agreement between the target solutions and MoodyMarine .Support for this work was given by the Swedish Energy Agency through Grant No. 50196-1, by Hugo Hammar’s Fund for Maritime Research through project No. 322, and by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No.101068736.</p
Försörjningsberedskap och resilient produktion av kritiska komponenter
No full textRapporten är resultatet av en studie som genomförts av RISE på uppdrag av Fortifikationsverket och MSB. Studien syftade till att stärka Sveriges förmåga till inhemsk produktion av kritiska produkter och komponenter vid kriser och höjd beredskap. Bakgrunden till projektet är det försämrade säkerhetsläget och erfarenheter från coronapandemin som visade på sårbarheter i globala leveranskedjor. Rapporten presenterar en strukturerad metod för produktionsomställning vid försörjningsbrister, där samverkan mellan myndigheter och näringsliv är central. Fokus ligger på alternativ produktion, snarare än traditionell lagerhållning, för att säkerställa tillgången på skyddsprodukter och reservdelar till samhällsviktig infrastruktur. Viktiga delar i processen är kartläggning av kritiska produkter, försörjningskedjor och svensk produktionskapacitet, samt utveckling av försörjningsstrategier som inkluderar återbruk och alternativa material. En tydlig metodik för nödproduktion redovisas, där målbild, kravspecifikation och produktionskapacitet analyseras systematiskt. Slutligen betonas vikten av säkerhetsskydd, scenarioplanering och samordnad styrning för att snabbt kunna skala upp produktion vid kriser. Rapporten är ett bidrag och verktyg för fortsatt utveckling av Sveriges försörjningsberedskap
