Sweco (Sweden)

Modeling heat transfer in packed bed processes such as iron ore pelletization is essential for optimizing process operation and furnace design. In these systems, materials like magnetite iron ore undergo thermal and chemical transformations, where heat and mass transfer are often coupled with heat effects from multiple processes — including both exothermic chemical reactions (e.g., oxidation) and endothermic physical changes (e.g., drying and sintering). As the industry moves towards fossil-free ironmaking, it becomes increasingly important to isolate pure heat transfer behavior, independent of chemical reactions, to support the development of sustainable process schemes. This study investigates convective heat transfer in a packed bed by evaluating several established correlations against the conventionally used modified Ranz–Marshall correlation. Pilot pot-scale experiments were performed by isothermally heating 120 kg of already indurated iron ore pellets at 300 °C to avoid chemical reactions, with additional experiments at 500 °C and 700 °C to assess performance at elevated temperatures typical of industrial pelletization. Results show that the modified Ranz–Marshall correlation underpredicts heat transfer rates under conditions isolating convective heat transfer, reinforcing the need for this investigation. The Wakao–Funazkri and Rowe–Claxton correlations provided the best agreement with experimental data, particularly at 300 °C. Minor deviations at higher temperatures suggest the influence of unaccounted variables, warranting further study. Sensitivity analysis identified gas velocity as the most significant parameter affecting heat transfer. The results suggest that adopting the Wakao–Funazkri and Rowe–Claxton correlations can provide a stronger basis for predictive pellet heat transfer modeling in future process design and simulation work. • Heat transfer models validated for packed beds at 300, 500 and 700 °C. • Rowe–Claxton and Wakao–Funazkri models provide the most accurate predictions. • Modified Ranz–Marshall model deviates more due to simplified porosity scaling. • Gas velocity strongly affects heat transfer; a 10% reduction improves model accuracy. • Temperature-dependent heat capacity enhances agreement between simulations and experiments. • Discrepancies at high temperatures suggest heat losses and non-uniform porosity effects.

Street experiments are proliferating in cities worldwide and have emerged as an approach to transform urban mobility and public space. Previous research attests to the broad spectrum of street experimentation and its variety of stakeholders, aims, methods, and impacts. In this article, we probe this multi‐faceted nature through a study of the landscape of street experimentation as it evolved in one city—Stockholm, Sweden—over a 10‐year period (2014–2023). Through document analysis and 19 semi‐structured interviews, we analysed stakeholder involvement, motives, and interactions related to four different platforms of street experimentation. Our temporal, evolutionary perspective moves beyond isolated case studies to show how experimental logics emerged over time in Stockholm via shifting ambitions, foci, and stakeholder constellations. The city‐specific perspective allowed us to analyse how experimentation develops and transforms as actors change, thus revealing dynamics of complementarity and competition, the addition or subtraction of layers, and successful as well as missed opportunities for between‐experiment learning. The article highlights the crucial role of municipal actors for implementation and scaling, but also their limited capacity to effect transformative change.

<strong class="journal-contentHeaderColor">Abstract.</strong> Sedimentary recycling of phosphorus is a key aspect of coastal eutrophication. Here, we present data on benthic fluxes of dissolved inorganic phosphorus (DIP) from the Baltic Sea, an area with a long eutrophication history. The presented dataset contains 499 individual fluxes measured in situ with three types of benthic chamber landers at 59 stations over 20 years, and data cover most of the Baltic Sea sub-basins (Hyl&eacute;n et al., 2025; <a href="https://doi.org/10.5281/zenodo.14812160" target="_blank" rel="noopener">https://doi.org/10.5281/zenodo.14812160</a>). The dataset further contains information about bottom-water dissolved oxygen (O₂) concentrations, sedimentary organic carbon (OC) content and sediment type. The DIP fluxes differ considerably between basins depending on OC loading and the level of O₂ depletion and generally increase from the coast to the central basins. Several stations have been visited on multiple occasions, also at times with different O₂ concentrations, which enables investigation of the immediate effects of shifting bottom-water O₂ concentrations on the benthic DIP release. The Baltic Sea-wide benthic DIP release is estimated to be 391 &ndash; 489 kton y^-1 based on a data integration based on sediment type and O₂ conditions during three years with varying extents of hypoxia and anoxia (2004, 2013 and 2018). The dataset reveals a lack of flux measurements in winter months, coastal areas and sandy sediments; these should be targeted in future studies. Overall, the data is of high quality and will be important for marine management and studies on mechanisms in benthic phosphorus cycling.

Abstract Life-cycle assessment (LCA) is widely used in certifications, regulations, and voluntary declarations covering the climate impact of buildings over their entire value chain. However, biodiversity impacts and other environmental impact categories are often disregarded. Conversely, there is a trend towards more systematic assessments of the biodiversity impacts that occur on-site as part of development projects (e.g. land transformation on the project site). However, off-site biodiversity impacts occurring throughout the rest of the value chain (e.g. from forestry activities, mining, manufacturing, heat and electricity production) are rarely considered. To bridge this gap, this article introduces the Doughnut Biotool, an open-source calculation tool to assess biodiversity impacts throughout the entire life cycle of development projects. The tool was initially developed to help implement Doughnut Economics and absolute sustainability principles in development projects. It constitutes a first step towards a better consideration of biodiversity impacts related to material- and energy use in building and construction projects. This paper presents the design of the tool and the method and data it relies on. The tool is applied to two separate case study projects, and used as a basis to discuss hotspots of biodiversity impacts within the building’s life cycle. Finally, the paper includes a discussion of the main challenges and opportunities for the future development and use of the tool, as well as for biodiversity impact assessments in the building sector as a whole.

PurposeNitrogen emissions from human activities are contributing to elevated levels of eutrophication in coastal ecosystems. Mechanisms involved in marine eutrophication show strong geographical variation. Existing life cycle impact assessment (LCIA) and absolute environmental sustainability assessment (AESA) methods for marine eutrophication do not adequately represent this variability, do not have a full global coverage, and suffer from other limitations, such as poor estimation of coastal residence times. This study aims to advance LCIA and AESA for marine eutrophication.MethodsWe aligned and combined recent advancements in marine eutrophication LCIA and AESA methods into one method. By re-running models underlying the combined methods and incorporating additional data sources, we included marine regions missing in previous methods and improved fate modeling, with the inclusion of denitrification and plant uptake in the air emission-terrestrial deposition pathway. To demonstrate and validate our method, we applied it in a case study.ResultsThe developed method allows the assessment of marine eutrophication impacts from emissions to soil, freshwater, and air at high resolution (0.083° and 2° × 2.5° for inland and air emissions, respectively) and spatial coverage (all ice-free global continents). In the case study, we demonstrate the added value of our method by showing that the now quantified spatial variability within spatial units, e.g., river basins, can be large and have a strong influence on the modeled marine eutrophication from the case study. Compared to existing methods, our method identifies larger occupations of safe operating space for marine eutrophication, mainly due to the high resolution of the coastal compartment, reflecting a more realistic areal extent of marine eutrophication impacts.ConclusionsAlthough limited by factors such as simulations based on a single reference year for modeling inland and air fate, our method is readily applicable to assess the marine eutrophication impact of nitrogen emitted to any environmental compartment and relate it to the safe operating space. With substantial advancement of existing approaches, our method improves the basis for decision-making for managing nitrogen and reducing emissions to levels within the safe operating space.

With the growing urgency of addressing climate change it is increasingly important that decision makers at all levels are equipped to take efficient mitigation actions. This research evaluates the potential of four mitigation strategies to reduce greenhouse gas emissions from the building stock based on a case study, and these are further evaluated in terms of alignment with the remaining global emission budget and the planetary boundary for global warming. The results cover annual emissions from 2023 to 2050 across 18 impact categories, thus highlighting possible impact burden-shifting that may occur as a result of the mitigation strategies. The results show that decarbonisation of the electricity grid delivers a substantial reduction across impact categories. However, in absolute terms, this is counteracted by the increase in building stock. The results also show that current estimates for mitigation potentials are insufficient to comply with the remaining global emission budget. Thus, mitigation strategies should be even more ambitious: constructing 80% fewer new buildings and reducing operational energy demand by 80%. These findings highlight the urgency of taking multiple actions. The increase in demand for new buildings needs to be challenged. Practice relevance Present urban mitigation strategies are inadequate for meeting the stated GHG targets. To enable informed decisions it is important to quantify the effects of different strategies. Traditional life cycle assessments have static inventories and impacts can therefore not be temporarily differentiated and transparency cannot be provided on long-term potentials. This study suggests combining material flow analysis and life cycle assessment to enable integration of dynamic parameters into the life cycle inventory. This shows how the long-term effectiveness of different mitigation strategies can be evaluated. To ensure unintended burden-shifting does not occur, results cover annual emissions from 2023 to 2050 across 18 impact categories. Furthermore, this study showcases how strategies can be designed to align with global commitments such as those set by the Paris Agreement.

In this study, MFA and LCA are coupled in a prospective analysis of the environmental impact of a building stock at a Danish university campus. The existing buildings are mapped and future growth is identified to create a dynamic LCA inventory. The prospective model is applied in a case study to determine the accumulated environmental impacts associated with the growth of the campus building stock from 2023 to 2050.The findings indicate that the national decarbonization of electricity and heat supply from 2023 to 2035 will deliver notable impact reductions, however the reduction in the overall impact of the building stock by 2050 will be counteracted by growth in new buildings and potential renovation activities. If decarbonization continues post-2035, impact will decrease for particularly global warming potential. The results allow identification of environmental impact hotspots, both spatially and temporally. This supports the development of mitigation strategies to reduce environmental impacts.

Nature-based solutions (NBS) are promising methods to enhance biodiversity and adapt to climate change in coastal areas. However, upscaling NBS to replace conventional methods requires knowledge about their performance from multiple perspectives, e.g., biodiversity, coastal safety, and economy. In recent years, great efforts have been put into researching NBS pilots of sandy solutions. Some of the most prominent examples are found in the Netherlands, e.g., the Sandmotor, the Hondsbossche Dunes, and the Prince Hendrik Sand dike. These are examples of large-scale interventions with nourished sand volumes of hundreds of thousands to millions of cubic meters. In contrast, this study focuses on small-scale NBS pilots of sandy solutions with nourishment volumes of hundreds to thousands of cubic meters. Two NBS pilots in Sweden are described and analysed, and the advantages and disadvantages of small-scale NBS are discussed in relation to larger-scale interventions. The first pilot was installed in 2018 in the Furusund navigational fairway in the Stockholm Archipelago. A few hundred cubic meters of sand was nourished to a beach subject to erosion due to ship-generated waves. The nourishment protects an eroding bluff and prevents the loss of forest areas with high nature values. Compared to hard solutions, e.g., a rock revetment, the small-scale beach nourishment supplies sand to a small sandy beach down-drift used for recreational purposes. Since the implementation, a significant part of the nourishment has already been eroded, and the expected lifetime of this intervention is in the order of a few years. The second pilot was installed at Fortuna beach, located in the narrow sound between Sweden and Denmark. The area has a low-energy wave climate, and the nourishment was designed to protect a beach in front of a residential area from storm erosion recurring with decadal frequency. The beach and dune area were nourished with approximately 3000 m3 of sediment. The area has limited offshore sand resources that can be extracted without adverse environmental impact. Therefore, the beneficial use of sediment dredged from local marinas and a mixture of sand and seaweed from nearby beach clean-ups was used to carry out the project. Within a year after the nourishment, a storm with a recurrence period of approximately 5-20 years hit the coast, but the dune volume still exceeded the volume before the measures. Experiences from the small-scale sandy solutions are that the limited extent of the interventions facilitates financing and permitting processes, which can be a bottleneck in upscaling NBS. The limited volume of nourishments makes it easier for beneficial use of dredged material, which in many cases is viewed as a waste rather than a resource. Both the volume and timing can be adapted to nearby dredging operations, thus reducing the cost of maintenance of small marinas with a high cultural value. The short lifetime and low safety level of small-scale NBS can be a disadvantage but allow for more flexibility, and no-regret solutions compatible with adaptive pathway approaches to climate change adaptation.

This paper presents a qualitative descriptive case study that aims to build awareness about the need for improvement of the indoor environment in classrooms and to exemplify how renewal-oriented processes can be initiated. The study focuses on innovation processes that have resulted in both completely new designs and further spread of innovative solutions. The reason for the need to improve is that too many pupils and students have problems with concentration, relaxation and recuperation. The number of diagnoses such as Autism and ADHD is growing. One factor which significantly influences the pupil’s mental well-being is the daily physical environment. The single aspect which may be improved in reasonable time, at a reasonable cost, is the lighting design of classrooms. An underlying reason for the habit to continue installing insipid uniform static “light-carpets” is the lack of awareness about how lighting affects wellbeing and health. As with innovation in other industries, it is an innovation dilemma that the vast majority of the people who sell and procure classroom lighting tend to prefer the established solutions that they are used to. The article describes how Malmö’s early investment in Human Centric Lighting and the unique indoor environment of the Study hall in the Centre for Economic Sciences at Uppsala University are used as role models for lighting design in classrooms. The case study combines the authors’ own observations and earlier interviews with users. Malmö’s temporal light variation and parts of the Study hall’s lighting design are used in more than 30 classrooms, in Malmö, Stockholm Business School and Iggesund. The article concludes with suggestions on how today’s lighting design knowledge and technology can be combined to provide more advanced adaptations to the varying lighting needs of pupils, students and teachers.

Parkeringsanalysen for Hørsholm Midtpunkt er gennemført med kameraregistrering og viser at parkeringsefterspørgslen ved Hørsholm Midtpunkt er anderledes end litteraturens værdier. Dermed kan parkeringsanalysen benyttes til at optimere antallet af p-båse ved ombygning og tilbygning af Hørsholm Midtpunkt, så der hverken er for mange eller for få p-båse i fremtiden.Sammenligningen af p-normer viser, at der ikke er en tendens i kommunernes p-normer i forhold til biler i kommunen og andel familier med bil. P-normer er i høj grad fastsat politisk. Tilsvarende har det været en udfordring at overføre resultaterne fra Holland til danske forhold og sammenligning med de omfattende hollandske studier om p-normer