RISE – Research Institutes of Sweden
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Biologisk metanisering av syngas från förgasning och pyrolys - lovande koncept mot implementering
No full textBiological 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.Projektet har finansierats av deltagande partners och Energimyndigheten (projektnummer 51438-1).</p
Metrology for reliable fuel consumption measurements in the maritime sector
No full textReliable fuel consumption measurements play an essential role in the maritime sector whether for emission determinations or the use of novel fuels. A verification of the performance of flow meters used for fuel consumption determination under realistic conditions is thus of interest. Apart from the influence of the pressure- and temperature-dependent transport properties of the fuels, a characterization of the measurement performance under dynamic fuel consumption is of relevance. Traceable metrological infrastructure and procedures, which will enable an evaluation of the measurement performance of flow meters in this regard, are being developed in the scope of the EMPIR project “Safest” (20IND13). A consumption profile of a ferry navigating in a harbour serves as basis. In addition to the measurement accuracy under dynamic conditions, first investigations of the performance of flow meters are carried out in terms of fluid temperature and fuel transport properties for the example of spindle screw meters.This project (EMPIR JRP 20IND13 SAFEST) has received funding from the EMPIR programme co-financed by the Participating States and from the European Union’s Horizon 2020 research and innovation programme.</p
Predicting Wind Comfort in an Urban Area : A Comparison of a Regression- with a Classification-CNN for General Wind Rose Statistics
No full textWind comfort is an important factor when new buildings in existing urban areas are planned. It is common practice to use computational fluid dynamics (CFD) simulations to model wind comfort. These simulations are usually time-consuming, making it impossible to explore a high number of different design choices for a new urban development with wind simulations. Data-driven approaches based on simulations have shown great promise, and have recently been used to predict wind comfort in urban areas. These surrogate models could be used in generative design software and would enable the planner to explore a large number of options for a new design. In this paper, we propose a novel machine learning workflow (MLW) for direct wind comfort prediction. The MLW incorporates a regression and a classification U-Net, trained based on CFD simulations. Furthermore, we present an augmentation strategy focusing on generating more training data independent of the underlying wind statistics needed to calculate the wind comfort criterion. We train the models based on different sets of training data and compare the results. All trained models (regression and classification) yield an (Formula presented.) -score greater than 80% and can be combined with any wind rose statistic.This work is part of the Digital Twin Cities Centre supported by Sweden’s Innovation Agency Vinnova under Grant No. 2019-00041. This work was further supported by the Swedish Research Council for Sustainable Development Formas under the grants 2019-01169 and 2019-01885. The computations were enabled by resources provided by the Swedish National Infrastructure for Computing (SNIC) at HPC2N partially funded by the Swedish Research Council through grant agreement no. 2018-05973.</p
Toward safer and more sustainable by design biocatalytic amide-bond coupling
No full textAmide bond synthesis is ranked as the second most important challenge in key green chemistry research areas identified by the ACS Green Chemistry Institute. While developing more sustainable amide bond forming reactions has been in focus, significantly less attention has been given to human toxicity and environmental aspects of the underlying amine and acid substrates and their corresponding coupled products, a potentially important contribution to the overall sustainability of the amide-bond-forming reactions. Here, we explore biocatalytic amide bond formation from a safer-and-more-sustainable-by-design perspective in which commercially available amines and acids as well as their corresponding amide products were evaluated in silico based on potential human toxicity and environmental fate and exposure. This in silico filtering resulted in a panel of 188 amine and 54 acid building blocks that could be classified as safe, referred to herein as “safechems”. To enable couplings of safechems, we generated a panel of robust and promiscuous ancestral ATP-dependent amide bond synthetases (ABS) using McbA from Marinactinospora thermotolerans SCSIO 00652 as a template. Ancestral ABS enzymes exhibited complementary specificities in the coupling of a representative safechem subset of 17 amines and 16 acids while showing an increased thermostability of up to 20 °C compared to the extant biocatalyst. Finally, the pool of safechems and their corresponding amides were evaluated by USEtox (the UNEP-SETAC toxicity model), analysing not only the intrinsic properties of the compounds but evaluating their complete impact pathway including fate, exposure and effects. The amides were in general predicted as more toxic compared to the starting acids and amines through non-additive effects, emphasising that focusing on the toxicity of the building blocks alone is not sufficient to strive towards low human and ecotoxicity impact. Pursuing a safer and more sustainable by design perspective in the implementation of safechems did not prevent us from generating an array of novel products with potentially potent applications as exemplified here by enzymatic synthesis of substructures that are part of drug candidates for e.g. cancer treatment. We greatly acknowledge funding from The Swedish Foundation for Strategic Environmental Research MISTRA, program SafeChem 2018/11. Computations were enabled by resources provided by the National Academic Infrastructure for Supercomputing in Sweden (NAISS), partially funded by the Swedish Research Council (VR) through grant agreement no. 2022-06725. We greatly acknowledge the PDC Centre for High-Performance Computing at the Royal Institute of Technology and SNIC and NAISS (projects NAISS 2023/5-395, NAISS 2023/5-232, naiss2024-5-346). This work was also supported by the Swedish Foundation of Strategic Research (FFF20-0027). This work was financially supported by the PARC project (Grant No. 101057014) funded under the European Union's Horizon Europe Research and Innovation program.</p
Dynamic process simulation for life cycle inventory data acquisition – Environmental assessment of biological and chemical phosphorus removal
No full textIn Sweden, phosphorus is commonly removed from municipal wastewater treatment by chemical precipitation (CP). Recently, such alternatives as enhanced biological phosphorus removal (EBPR) have garnered interest due to the increased risk of chemical shortage. In this study, a life cycle assessment (LCA) was performed to compare EBPR and CP in three scenarios: 1) baseline – precipitation chemicals available, 2) stricter effluent requirements – precipitation chemicals available, and 3) chemical shortage – no precipitation chemicals available. Data acquisition that was based on dynamic process simulation was useful, yielding more site-specific results, in contrast to standard literature values. The results indicated substantial differences in greenhouse gas emissions between configurations (around three times higher methane emissions for EBPR compared to CP configurations – although this finding requires further validation). These differences suggest that different emission factors for EBPR and CP should be considered. Furthermore, it is suggested to include waterline methane emissions, at least when the configuration incorporates anaerobic reactors in the water line. Further validation of emissions is necessary, especially for EBPR plants with side-stream hydrolysis and digester reject water treatment. The LCA results showed a similar overall environmental impact for both configurations, but the results of individual impact categories differed. EBPR caused greater climate impact due to the larger direct emissions of methane. Toxicity was more important for CP, based on the inherent heavy metal content in precipitation chemicals. Freshwater eutrophication was similar for both configurations, assuming that precipitation chemicals were available. However, if the recipient is sensitive, implementing EBPR reduces the freshwater eutrophication potential by 75% during a chemical shortage, and should be considered. This project was funded by the Swedish Environmental Protection Agency (Naturvårdsverket), the research cluster VA-teknik Södra (Swedish Water and Wastewater Association), and the LIWE life ENV/SE/000384 project.</p
Water wave simulations using fully nonlinear potential flow : Spectral/hp element models implemented in Nektar++
No full textThis work is supported by the Swedish Energy Agency through grant no. 51388-1 obtained by CE. This work issupported by the Danish COWIFONDEN through project no. A-165.19 obtained by APEK. </p
Literature study: The performance of carbon dioxide systems on ro-ro vehicle carriers
No full textThe performance of carbon dioxide systems during vehicle fires on ro-ro vehicle carriers has not been documented. The first part of the report documents such fires. From 2013 to 2023, at least 22 severe fires started in the cargo space of ro-ro vehicle carriers. Eight fires started during loading operations (i.e., when the doors and ramps are open) and fourteen started while at sea. In eleven of the 22 fires, the found information verifies that a carbon dioxide system was used. In five of these verified incidents, the fire was suppressed or extinguished, in five of the incidents the fire was not suppressed nor extinguished, and in one case information about the performance is lacking. For the cases when fire was not extinguished, a long delay time combined with the fact that the space was not sufficiently sealed may explain the failure. Electrical failure, including short circuits, is a commonly noted fire cause in used cars onboard. One of the 22 fires probably originated in a new production electric vehicle; no other fires in electric vehicles were documented. The second part of the report documents fire suppression tests. However, there are few fire suppression tests with lithium-ion batteries and carbon dioxide in the scientific literature. Findings include small-scale tests with handheld/portable fire extinguishers and not fixed, total-flooding systems. The identified studies indicates that full fire extinguishment of lithium-ion battery fires may not be possible with carbon dioxide. While carbon dioxide may not extinguish and cool down a battery cell effectively to prevent thermal runaway propagation, it may reduce the risk of fire spreading to nearby vehicles and other combustible materials. This has not been investigated and is part of the upcoming objectives in the COFFEE project. Traditional search tools and engines were used to collect fire investigation reports, media articles, and research studies for this report.The project was funded by Stiftelsen Sveriges Sjömanshus (the Swedish Mercantile Marine Foundation) and Trafikverket (the Swedish Transport Administration).</p
Metoder för indikering och sanering
No full textInom ramen för Myndigheten för samhällsskydd och beredskaps (MSB) pågående arbete med uppbyggnaden av räddningstjänst under höjd beredskap (RUHB) sker utveckling av bland annat förmågan till indikering och sanering av kemiska, biologiska och radioaktiva ämnen anpassad till dagens hotbild. Som en del i underlaget för utvecklingen har information om olika metoder för indikering och personsanering inom räddningstjänst inhämtats från omvärlden
Enhancing Cybersecurity through Comprehensive Investigation of Data Flow-Based Attack Scenarios
No full textIntegration of the Internet of Things (IoT) in industrial settings necessitates robust cybersecurity measures to mitigate risks such as data leakage, vulnerability exploitation, and compromised information flows. Recent cyberattacks on critical industrial systems have highlighted the lack of threat analysis in software development processes. While existing threat modeling frameworks such as STRIDE enumerate potential security threats, they often lack detailed mapping of the sequences of threats that adversaries might exploit to apply cyberattacks. Our study proposes an enhanced approach to systematic threat modeling and data flow-based attack scenario analysis for integrating cybersecurity measures early in the development lifecycle. We enhance the STRIDE framework by extending it to include attack scenarios as sequences of threats exploited by adversaries. This extension allows us to illustrate various attack scenarios and demonstrate how these insights can aid system designers in strengthening their defenses. Our methodology prioritizes vulnerabilities based on their recurrence across various attack scenarios, offering actionable insights for enhancing system security. A case study in the automotive industry illustrates the practical application of our proposed methodology, demonstrating significant improvements in system security through proactive threat modeling and analysis of attack impacts. The results of our study provide actionable insights to improve system design and mitigate vulnerabilities. This research was funded by the Swedish Foundation for Strategic Research throughthe Serendipity project and KKS SACSys Synergy project (Safe and Secure Adaptive CollaborativeSystems, Grant No. 20190021) </p