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| 2. |
- Aurell, Emelie, et al.
(författare)
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Mikroplaster : Redovisning av regeringsuppdrag om källor till mikroplaster och förslag på åtgärder för minskade utsläpp i Sverige
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- I augusti 2015 fick Naturvårdsverket i uppdrag från regeringen att identifiera viktigare källor i Sverige till utsläpp av mikroplaster till havet och verka för att reducera utsläppen från dessa källor. I den här rapporten redovisar Naturvårdsverket uppdraget. Vi presenterar resultaten från den första, övergripande kartläggningen av källor till och spridning av mikroplaster i Sverige, en bedömning av vilka av de kartlagda källorna som primärt bör åtgärdas samt vilka steg som behöver tas för att förebygga utsläpp och minska spridning av mikroplaster till hav, sjöar och vattendrag från dessa källor.Förekomsten av mikroplast i den marina miljön har uppmärksammats allt mer under senare år, inte minst på global nivå. Mikroplast är ett samlingsnamn för små, små plastfragment (1 nm till 5 mm). De mikroplaster som hittats i världshaven, men även i sötvattensystem, har olika ursprung. Mikroplast kan bildas oavsiktligt när plastföremål slits och plastpartiklar frigörs, eller när vi inte återanvänder, återvinner eller slänger plastmaterial på rätt sätt utan plasten blir skräp som succesivt bryts ned till mindre och mindre bitar i naturen. Det finns också plast som från början tillverkas som små pellets eller korn.Utgångspunkten för arbetet har varit miljökvalitetsmålen Hav i balans samt levande kust och Levande sjöar och vattendrag samt målet om Giftfri miljö. Reduceradeutsläpp av mikroplaster till hav, sjöar och vattendrag bidrar till att nå dessa mål.Uppdraget har genomförts av Naturvårdsverket i samarbete med Havs- och vattenmyndigheten, andra berörda myndigheter, samt med deltagande av berörda organisationer och andra intressenter mellan augusti 2015 och maj 2017. Slutsatserna är Naturvårdsverkets egna.
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| 3. |
- Bohman, Anna, 1975-, et al.
(författare)
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Visual Water : En visualiseringsplattform för dagvatten- och skyfallsplanering i ett klimat under förändring
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Visual Water (http//visualwater.se) är en interaktiv webbaserad visualiseringsplattform som syftar till att stötta svenska kommuner i arbetet för en hållbar dagvatten- och skyfallshantering. Plattformen är utformad för att svara mot centrala utmaningar som lyfts av svenska dagvattenaktörer som befinner sig i skiftet bort från de rörbundna nätverksidealen för avledning av dagvatten och strävar efter en högre grad av grön-blå och öppna lösningar i stadsmiljön.
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| 4. |
- Brown, Calum, et al.
(författare)
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Understanding farmer uptake of measures that support biodiversity and ecosystem services in the Common Agricultural Policy (CAP) : An EKLIPSE Expert Working Group report
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Recent scientific research highlights the urgent need to protect Europe’s remaining – and rapidly declining– biological diversity. The Common Agricultural Policy (CAP) is one of the major tools with which policymakers in the European Union (EU) can achieve this aim. However, so far, the CAP has proved largely ineffective – or even detrimental – to this goal. With relatively localised exceptions, the Policy’s notable success in ensuring supplies of food and fiber by supporting Europe’s farmers has been at the expense of environmental objectives. This report presents the findings of an Expert Working Group (EWG) convened to explore the ways in which the Common Agricultural Policy could be made more effective in protecting biodiversity and delivering associated ecosystem services, particularly through the implementation of effective biodiversity measures by Europe’s farmers. The EWG was established with a focus on Ecological Focus Areas (EFAs), a policy instrument introduced tothe CAP in the period 2014 - 2020, who broadened this remit to also consider evidence from other measures. In the first of three main strands of research (Step A), we synthesised the findings of recent reviews that investigate the most beneficial measures for biodiversity on farmland. In the second (Step B), we reviewed the factors affecting the design and selection of these measures at European, national and farm scales. In the third (Step C), we used our findings to develop recommendations for improving the impacts of the CAP on biodiversity and associated ecosystem services. The bulk of our work focused on Step B, in particular a new assessment of factors affecting farmer’s uptake of relevant measures, and a series of interviews with farmers’ representatives to further develop our insights and findings.
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| 6. |
- Dersjö, Tomas, et al.
(författare)
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A directional surrogate model tailored for efficient reliability based design optimization
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Reliability based design optimization (RBDO) aims at minimizing an objective while constraining the failure probability of structural components. Due to the iterative nature of both the minimization and the failure probability validation, there is considerable computational effort associated with it. In this paper, a computationally inexpensive approach for RBDO is presented. The key contribution is the directional surrogate model and its associated advantages; a sound balance between accuracy and computational cost, including the possibility to fit model coefficients based on an optimal experiment design, high fidelity modeling of representative structural responses, treatment of multiple constraints without added computational cost, and straightforward sequential linear programming implementation. The directional surrogate model is of power type with nonlinear behaviour only in the gradient direction, thus balancing accuracy and computational cost. Moreover, information from prior iterations are used in every iteration in a weighted least squares optimization. When benchmarked against existing approaches from the literature using a well known reference problem, it is shown to be highly efficient. It also shows promising stability and convergence rate for additional challenging problems to which it has been applied.
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| 7. |
- Dersjö, Tomas, et al.
(författare)
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Reliability based design optimization with experiments on demand
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In this paper, an algorithm for reliability based design optimization (RBDO) is presented. It incorporates a novel procedure in which experiments are performed one at a time where and when they are needed. The procedure is called experiments on demand. The experiment procedure utilizes properties specific to RBDO and the problem at hand augmented by the concept of D-optimality familiar from traditional design of experiments. Furthermore, an adaptive surrogate model fitting scheme is proposed which balances numerical stability and convergence rate as well as accuracy. Benchmarked against algorithms in the literature, the number of experiments needed for convergence was reduced by up to 80 % for a frequently used analytical problem and by up to 19 % for an application example. The accuracy of the reliability index is in line with the most efficient algorithm against which it was benchmarked but up to 3 % lower than the most accurate algorithm.
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| 8. |
- Fagerström, Anton, et al.
(författare)
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Large scale bio electro jet fuel production integration at CHP-plant in Östersund, Sweden
- 2021. - B 2407
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This document reports the findings of the project “Large scale bio electro jet fuel production integration at CHP-plant in Östersund, Sweden”. BEJF is an electrofuel produced in a synthesis process where biogenic carbon dioxide (CO2) is the main carbon source and hydrogen from electrolysis of water using renewable electricity is the main energy source. The project is a feasibility study for a factory for such fuel located at Jämtkraft's facility for CHP in Östersund. Thus, the aim of the project is to assess the feasibility for producing renewable aviation fuel at a specific location considering and evaluating e.g., different processes, operations and integrations, costs, environmental impact, business models and actors.IVL The Swedish Environmental Research Institute, Jämtkraft (JK), Chalmers University (CU), Lund University (LU), Nordic Initiative for Sustainable Aviation (NISA), and Fly Green Fund (FGF) have been the primary implementers in this project. Other project stakeholders (AFAB, and The Power Region), have provided relevant data to the various working groups. The project has included experimental work, modelling and calculations, as well as literature-based studies but not the construction of any facilities.
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| 9. |
- Gillblad, Tomas, et al.
(författare)
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Implementation Problems for Activated Sludge Controllers
- 1978
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The paper describes some problems that appear in the implementation of a computer control system in a wastewater treatment plant. The problems are related to the control authority of the actuators, the influence of the process design on the controller design, or the disturbance pattern. Some experience from two full scale activated sludge plants in Sweden are discussed.
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| 10. |
- Gunnarsson, Carina, et al.
(författare)
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Utvinning av högvärdiga komponenter för förbättrad värdekedja för vall till etanol och bioolja
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Grass-clover ley holds an importance role for a sustainable crop production and is mainly used as feed for ruminants. But ley also contains proteins, if extracted, suitable for monogastric animals such as pigs and poultry. If these proteins are extracted, the degree of self-sufficiency of proteins in Sweden can increase and better resource utilization is achieved. In this study we evaluated the utilization of fresh and ensiled grass-clover ley in a straw-based agricultural biorefinery for producing protein concentrate, ethanol, bio-oil and biogas.Practical lab scale tests of extraction of high value components for food and feed applications from the liquid fraction after ley pressing were carried out. Pretreatments of the solid fraction prior to ethanol fermentation, bio-oil production using HTL (hydrothermal liquefaction) and biogas production were tested. The system for production and supply of the ley was described and the potential for increased ley production in Sweden was quantified. The environmental and economic efficiency of the proposed biorefinery system was evaluated using environmental systems analysis and technoeconomic assessment.In terms of system profitability, a high protein yield in the extracted protein concentrate it is important. To achieve that, a thorough pre-treatment using mechanical biomass disintegration before fractioning is crucial. This may need to be done in several steps. Screw pressing is a common technique for fractionating ley into a liquid and solid fraction. Double pressing combined with enzymatic treatments or only water addition during the second pressing stage were found to increase the protein yield compared to single pressing. Second pressing had no effect on the amino acid profile of the protein concentrate.After pressing fresh ley, heat coagulation or isoelectric precipitation can be used to precipitate protein concentrates in one- or two-step processes to produce protein fractions with different functional properties. Tests showed that it is possible to recover chlorophyll and carotenoids from the ley using supercritical carbon dioxide extraction. which is a suitable method for food applications as toxic organic solvents can be avoided. The ensiling process degrades the protein into smaller peptides or free amino acids which makes ensiled grass less suitable for protein recovery by heat coagulation or isoelectric precipitation. Fresh and ensiled timothy and meadow fescue showed a similar amino acid profile as soybeans.The initial hypothesis that mechanical pressing may disintegrate the lignocellulosic structure of ley sufficiently to produce a sugar stream with a high concentration of sugar for further fermentation by enzymatic hydrolysis was not confirmed. The content of sugars released after the enzymatic hydrolysis was relatively low. The fibre fraction after the mechanical pressing can be suitable for ethanol production if an additional pretreatment method will be incorporated. Fermentation of pressed and steam-exploded ensiled mixed ley showed promising results. The bio-oils produced with the HTL-process were described of high quality, i.e., high carbon content and low ash content. Although, the obtained materials are not directly integrable in today's refineries, the ensiling did not seem to affect the material's potential for biofuel production. The methane potential tests that were carried out in the project of the liquid residual fraction after protein extraction and after the HTL process showed that both can be suitable for methane production, but they showed great behavior differences.The results from the environmental system analysis showed that extraction of high-quality products from ley, straw and sawdust according to the studied system reduces climate impact (CO2 eq) when the use of ethanol, bio-oil and biogas replaces fossil fuels, protein concentrate replaces soy as feed and carbon dioxide replaces fossil carbon dioxide. At present, the climate impact from extracted protein concentrate is higher than for soybean meal. Grass source for protein extraction followed by ethanol and bio-oil production as an alternative to straw-based ethanol and bio-oil production did not seem to improve the profitability of the studied biorefinery system. Profitability may be improved if protein extraction is performed the whole all year and not seasonal. Higher prices of the extracted protein concentrate may also improve profitability.The potential for increased grassland cultivation in Sweden for biorefining was estimated at approximately 3.4 million tonnes grass per year. This included incorporating grassland in the crop rotation in grain-dominated areas, intensification of existing grassland cultivation, utilization of fallow and abandoned arable land for grassland cultivation.Based on the results and the experience acquired from this project, we suggest an extraction plant for grass-clover ley that operates for both fresh and ensiled grassland all year. The plant needs to be supplemented with more advanced technologies such as membrane filtration for the extraction of amino acids from the ensiled ley during the winter season. The protein extraction plants should be located near farms. The extraction plant is also suggested to be located together with a biogas plant to enable co-digesting residual fractions with manure. Thereby, enabling plant nutrients and minerals in digestate to be returned to arable land. Utilizing the solid fiber fraction for biofuel production with fermentation and HTL in large-scale processes remains promising.
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