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Water and Carbon Balance Modeling: Methods of Uncertainty AnalysisJuston, John January 2010 (has links)
How do additional data of the same and/or different type contribute to reducing model parameter and predictive uncertainties? This was the question addressed with two models – the HBV hydrological water balance model and the ICBM soil carbon balance model – that were used to investigate the usefulness of the Generalized Likelihood Uncertainty Estimation (GLUE) method for calibrations and uncertainty analyses. The GLUE method is based on threshold screening of Monte Carlo simulations using so-called informal likelihood measures and subjective acceptance criterion. This method is highly appropriate for model calibrations when errors are dominated by epistemic rather than stochastic uncertainties. The informative value of data for model calibrations was investigated with numerous calibrations aimed at conditioning posterior parameter distributions and boundaries on model predictions. The key results demonstrated examples of: 1) redundant information in daily time series of hydrological data; 2) diminishing returns in the value of continued time series data collections of the same type; 3) the potential value of additional data of a different type; 4) a means to effectively incorporate fuzzy information in model calibrations; and 5) the robustness of estimated parameter uncertainty for portability of a soil carbon model between and tropical climate zones. The key to obtaining these insights lied in the methods of uncertainty analysis used to produce them. A paradigm for selecting between formal and informal likelihood measures in uncertainty analysis is presented and discussed for future use within a context of climate related environmental modeling. / QC 20110414
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What can a National Park bring to Gotland? : A case study on Bästeträsk National Park in SwedenAlberti, Giorgia January 2021 (has links)
The role of community participation in protected areas has long been debated. Sweden is in the process of establishing two new National Park, of which one is located on the island of Gotland. In order to figure out the best approach to management of the area, it is important to listen to the residents. Through a qualitative study, I have therefore investigated whether residents would like to be included in the Park implementation and management, along with how the National Park could help Gotland reach its sustainability agenda by 2040. The findings show that communities are eager to be included in the National Park project, but also that Region Gotland should revise the way they address regional development.
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Lustgasemissioner från ryaverket och dess klimatpåverkan : Utvärdering av lustgasmätningar / Nitrous oxide emissions from Ryaverket and its climate impact : Evaluation of nitrous oxide measurementsAli, Sabrin, Pereira, Elizama January 2021 (has links)
Sveriges avloppsreningsverk står inför ett antal utmaningar, där en av utmaningarna är minskning av växthusgaser. Lustgas är en av dessa växthusgaser, som bildas vid rening av avloppsvatten. Lustgas är 300 gånger skadligare för klimatet i jämförelse med koldioxid. Dessutom påverkar den nedbrytningen av ozonskiktet. I dagsläget är det svårt att mäta och uppskatta lustgasutsläpp, på grund av att det pågår flera samtidiga processer på stora ytor. För att driften av avloppsreningsverk ska ske på ett effektivt sätt och med en ytterst liten miljöpåverkan måste man kunna förstå hur lustgas uppstår och hur bildningsprocesserna samverkar med de andra reningsprocesserna och driftparametrarna. Utsläpp av lustgas har studerats vid avloppsreningsverket i Göteborg. Syftet har varit att tillhandahålla resultat och mätningar från Gryaab AB reningsverk och fastställa vilka processer som ger upphov till störst eller minst lustgasemissioner. Utsläpp av lustgasemissioner har mätts från rejektrening med nitrifikation och denitrifikation process. Analyser på resultaten ska förhoppningsvist kunna hjälpa Gryaab AB med fortsatt studier om lustgas. Som mätningsmetod användes EPA-huvmätning som man mätte med ovanför vattenytan på bassängerna och mobilt extraktiv FTIR som åkte runt anläggningen. Den dominerande källan för lustgas visade sig bildas allra mest i nitrifikationsprocessen. Där mätningarna med huv-mätning och stickprov visade totala utsläpp motsvarande 1,8 ton N2O/år. Den totala lustgasemissionen från biologiska reningsprocessen visade totala utsläpp motsvarande 3,5 ton N2O/ år. Som en slutsats bör fler mätningar med olika mätningsmetoder och mer studier göras för att få en bättre överblick till varför och hur lustgas bildas. Samt vilka åtgärder som kan minska lustgasemission. Det finns ett behov av fortsatta studier med mätningar med olika mätningsmetoder på Gryaab AB. / Sweden's wastewater treatment plant faces several challenges, one of them is the reduction of greenhouse gases. Nitrous oxide is one of these greenhouse gases, which is formed during the purification of wastewater. Nitrous oxide is 300 times more harmful to the climate compared to carbon dioxide. In addition, it affects the depletion of the ozone layer. At present, it is difficult to measure and estimate nitrous oxide emissions, since several simultaneous processes are taking place on large areas. For the operation of sewage treatment plants to take place in an efficient manner and with an extremely small environmental impact, it is important to understand how nitrous oxide is formed and how the formation processes interact with the other treatment processes and operating parameters. Emissions of nitrous oxide have been studied at the wastewater treatment plant in Gothenburg. The purpose has been to provide results and measurements from Gryaab AB wastewater treatment plant and to determine which processes give rise to the highest nitrous oxide emissions. Emissions of nitrous oxide emissions have been measured from reject cleaning with the nitrification and denitrification process. Analysis of the results will hopefully be able to help Gryaab AB with further research. As a measurement method, EPA hood measurement was used, which was measured above the water surface in the basins and mobile extractive FTIR was driven around the facility. The dominant source of nitrous oxide was found to be formed most in the nitrification process. Where the measurements with hood measurement and sampling showed total emissions corresponding to 1.8 tons of N2O / year. The total nitrous oxide emissions from the biological treatment process showed total emissions corresponding to 3.5 tons of N2O /year. As a conclusion, more measurements with different measurement methods and more research should be done to get a better overview of why and how nitrous oxide is formed. And what measures can reduce nitrous oxide emissions. There is a need for further studies with measurements with different measurement methods on Gryaab AB.
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Exploring the sustainable development of garden tourism with Chinese characteristicsNie, Mengxue January 2021 (has links)
Both garden ontology and tourists influence garden tourism, and while many countries around the world have researched garden tourism, China's garden tourism market lacks development. This study aims to find a sustainable and distinctive development path for garden tourism development in complementary developed China. This study uses primarily qualitative research to interview visitors to Chinese garden tourism sites, using visitor experience factors and international case studies to explore the development of Chinese garden tourism. The study results show that Chinese gardens are characterized by developing essential elements: discovering tourism values, increasing infrastructure development, innovative management, and creating a and connotation of sustainable development. Thus, the study project will fill the gap in the development of garden tourism in China and provide a creative direction for the development of garden tourism in China.
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Improved prediction of biogas production at Uddebo wastewater treatment plant : Substrate modelling in SIMCAGullman, Isak January 2021 (has links)
Anaerobic digestion is a complex process, dependent on multiple factors, which can be made more stable and efficient with the help of process models. A more stable process could reduce biogas torching, which increases the amount of renewable energy available for heat- and electricity production and vehicle fuel. Fluctuations in the produced biogas at Uddebo WWTP in Luleå, Sweden, has been observed, where imported industrial waste was suspected to be the cause. The purpose of this master thesis was to increase the predictability of the biogas production at Uddebo WWTP by creating a process model based on historical data. The historical data consisted of quantitative data of the substrates loaded into the anaerobic digestor and biogas collected from the digestor. The results showed that the calculated error between modelled and measured biogas production was <20%, which was considered good. However, due to the demarcation of this report, many variables were ignored in the creation of the model. Further research is therefore a requirement for the model to function properly: The error should be reduced to <10%, This could be done by increasing the period and resolution toinclude and statistically secure fast and seasonal variations. make qualitative modelling easier, i.e., prediction of the biomethane amount in the biogas. The industrial liquid waste storage should be included in the calculation. A more detailed analysis of all substrates is needed to make the comparison between the literature based and measured production more realistic. Expanding the demarcation of the model to also include the environment in the digestor. This could also increase the total amount of biogas produced.
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Analysis and optimization of a dissolved air flotation process for separation of suspended solids in wastewaterBäck, Oskar January 2021 (has links)
Margretelund wastewater treatment plant (WWTP) operated by the water utility Roslagsvatten AB, wasbuilt in 1956 and is located in Åkersberga town, Stockholm County, Sweden. Margretelund WWTP waslast renovated in 1999, and has been operated with the same physical, chemical, and biological processessince then. Due to issues with increased phosphorus emissions connected to increased concentration ofeffluent total suspended solids (TSS), Roslagsvatten would like to optimize the operation of their dissolvedair flotation (DAF) process and the author was tasked to conduct a study about the subject. The specificaim of the study was to propose one method for optimization with available means to reduce effluentTSS concentration during high flow rates for the present DAF process at Margretelund WWTP.Achieving the aim required an historical analysis of Margretelund WWTP’s DAF process and aninvestigation of the effect influent flow rate and effluent recycle rate (ERR) had on effluent TSSconcentration. The increase of effluent TSS was believed to be caused by increased flow rates frominfiltration and inflow (recorded to 32% of total volume the year 2020) affecting the dissolved air flotation(DAF) process.The literature study design parameters for a dissolved air flotation process, specifically the recycle flowpressurization configuration, generated information about which parameters to take into considerationwhen optimizing a DAF unit. Analysis of historic effluent measurements at Margretelund showed that42% of all samples analysed between January 2015 – January 2021 were below 10 mg/l TSS. Eachhistorical increase of surface load has brought a decreased effluent recycle rate (ERR) and consequentlyan increasing percentage of samples exceeding 10 mg/l. A Pearson correlation presented a negativecorrelation with both ERR and surface load in relation to effluent TSS concentration. This resulted inthe selection of the experimental factors ERR and surface load to be investigated in this study.Margretelunds WWTP’s DAF design of ERR being 10-15% and the design surface load of 4 m/h wasthe base values for the experimental runs. Increases of ERR percentage was done during the experimentfor four different surface loads (2.5, 4, 5 and 6 m/h), with five steps between 15% up to 35% ERR inone of the three parallel DAF units in Margretelund WWTP. TSS in the effluent was constantlymonitored using a TSS sensor. Influent TSS was measured at Roslagsvatten’s accredited laboratory in a24h composite sample with 1 hour for each sub-sample.The results showed that both the highest and the lowest ERR settings tested provided the lowest averageeffluent TSS concentrations. However, a decreased surface load was found to lower effluent TSSconcentration and ERR providing only minor differences within each surface load. Largest surface loadpossible was found to be 5 m/h, for an ERR of 15 or 35%. Surface load less than 5 m/h provided aconcentration under 10 mg/l for all ERR setting. / Margretelund avloppsreningsverk (ARV) placerat i Åkersberga, Stockholms län, byggdes 1956 och drivs av Roslagsvatten AB. Margretelund ARV har sedan 1956 renoverats vid två tillfällen senast 1999. Samma reningsprocess för fysisk, kemisk och biologisk rening har använts sedan senaste renoveringen. Roslagsvatten har haft problem med oönskat tillskottsvatten (motsvarade 32% av total volym 2020) som har påverkat deras flotationsprocess negativt gällande rening av suspenderat material. Detta har till slut lett till förhöjda utsläppsvärden av fosfor som finns bundet i det suspenderade materialet. Denna studie har utförts av författaren på efterfrågan av Roslagsvatten, med syfte att presentera optimeringsåtgärder till styrning av flotationsprocessen vid höga flöden. För att uppnå målet med studien gjordes en historisk analys av Margretelunds flotationsprocess samt undersökningar om hur variationer i inkommande flöde samt recirkuleringsgrad har påverkat koncentration av utgående suspenderat material.Teori undersöktes och information insamlades angående designparametrar gällande optimering av flotationsprocesser, mer specifikt en flotationsprocess med recirkulerat trycksatt flöde för avskiljning av susp. Analys av historiska utsläppsvärden från Margretelund ARV’s flotationsprocess visade på att 42% av proverna analyserade mellan januari 2015-januari 2021 låg under 10 mg/l för utgående suspenderat material. Varje historisk ökning av ytbelastning påvisade en minskande recirkuleringsgrad samt en ökande andel prover som översteg koncentrationen 10 mg/l. Utifrån en Pearson korrelation visades en negativ korrelationen för både ytbelastning och recirkulationsgrad gentemot koncentration av utgående suspenderat material. Både recirkuleringsgrad och ytbelastning valdes därför till denna studies experimentella faktorer. Flotationsprocessen på Margretelund ARV’s var designad för en recirkuleringsgrad på 10–15% vid ytbelastning på 4 m/h, och valdes som basvärde för experimentet. Fem olika grader av recirkulation testades för fyra olika ytbelastningar (2.5, 4, 5 och 6 m/h) i intervallet 15–35% i en av tre parallella flotations bassänger på Margretelund ARV. Koncentration utgående suspenderat material mättes kontinuerligt med en sensor. Inkommande koncentration bestämdes genom ett dygnsprov som analyserades av Roslagsvattens ackrediterade laboratorium.Ett resultat från experimenten var att både den högsta och lägsta inställningen av recirkuleringsgrad visade de lägsta medelvärdena för utgående koncentration av suspenderat material. Dock, visade resultaten att en minskande ytbelastning resulterade i lägre koncentrationer av utgående suspenderat material. Vidare sågs att recirkuleringsgraden enbart hade en låg påverkan på koncentrationerna för varje ytbelastning. Den högsta möjliga ytbelastningen utan att överstiga 10 mg/l visades vara 5 m/h med recirkuleringsgraderna 15% och 35%.
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Elucidating the Influence of Food Packaging Attributes on Source-separation of Food Packaging Waste at HomeNemat, Babak January 2020 (has links)
The global amount of waste generated by households, including food packaging waste, has been increasing continuously across the world, posing a massive threat to societies and the environment. Proper waste management, therefore, has become a challenging environmental issue and a priority for governments. Along with the technological advances, such as material recovery technologies, more stress has been placed on the strategies for moving away from disposal to waste prevention, separation, and recycling. Considerable efforts are being made to not only limit the overall production and the negative impact of waste on the environment and human health but also to minimize the cost of waste management. Separation of wastes at the source (i.e., source separation) is an integral part of such efforts toward enhancing the purity of collected waste and improving the quality of materials for recycling. Furthermore, sorting of waste as a habitual performance can serve as a practice for improving residents' recycling/sorting behavior. The packaging waste, including food packaging, forms a significant part of the municipal solid waste. The design of food packaging, therefore, has received a lot of attention as a useful tool to influence the consumers' sorting behavior, making it an interesting concept for research related to waste management. Presumably, the design of food packaging can meet consumers' sorting demands while being instructive and facilitating the sorting process, thus enhancing the recycling rate of the food packaging waste. Finding the ideal form of food packaging, however, requires an in-depth understanding of the packaging-consumer interactions throughout the sorting process. Considering the different characteristics of food packaging, it is expected that different food packages tend to influence a consumer in different ways. Nevertheless, the current knowledge is somewhat too general to be used by packaging developers to improve the sorting of the food packaging. Hence, the present thesis aims to provide a more in-depth insight into the influence of food packaging, as a product and service provider, on the consumer's/user's decision-making on sort of food packaging waste. The results assert that packaging to be sorted properly requires proper design to manifest its sorting related abilities such as easy to empty, easy to clean, and easy to fold, for the consumer. Selecting material, visual attributes, form, and function can amplify or reduce these sorting abilities of food packaging.
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Utvärdering av predikteringsmetoder för sulfidförande berg : Med fokus på berg som används i konstruktionerLindgren, Lina January 2020 (has links)
Ett cirkulärt samhälle strävar efter att efterlikna naturens kretslopp där material som blir över från en verksamhet används i en annan, för att minska uttag av jungfruliga resurser. Från verksamheter kopplade till vägbyggen är det främst geologiska material som hanteras. Bergmaterial kan innehålla sulfidmineral som vid oxidation kan producera syra. För att säkerställa att bergmaterialet kan användas på ett säkert sätt används olika predikteringsmetoder för att identifiera risker med materialet, projektet har studerat några av dessa predikteringsmetoder och resultatet visar att de ger mycket osäkra bedömningar av det studerade materialet. I detta examensarbete har 10 bergmaterial studerats med syfte att undersöka och diskutera predikteringsmetoder och hur dessa kan tillämpas och tolkas för sulfidförande berg. Bergmaterialet har en kemiskt analyserad svavelhalt mellan 0,3 och 1,6 vikts-%. Undersökningen inkluderar statiska och kinetiska tester. De statiska tester som använts är ABA och NAGpH, mineralogiska studier, både kvalitativt och i optiskt mikroskop och kvantitativt i SEM, XRF-mätningar, även ett enkelt laktest har utförts på materialet. Kinetiskt fuktkammartest (40 veckor) har inom ramen för projektet påbörjats på tre av bergmaterialen. Resultaten av predikteringstesterna visar på en stor variation mellan materialen utifrån använda riktvärden. Bedömningen av syrapotentialen och neutralisationspotentialen visar också stora variationer utifrån nyttjade riktlinjer. Det finns behov att vidare undersöka vad det är som gör att predikteringsmetoderna ger det resultat de ger och vidare hur detta kan tolkas. Statiska predikteringstester visar inte heller någon tidsaspekt som är viktigt att betrakta vid prediktering av material. Kinetiska test, som fuktkammartest visar hur utlakningen varierar med tiden. Hur provtagningen av materialet utförs har också en stor påverkan på resultatet, det är därför viktigt att fortsatt utreda hur en representativ provtagning kan utföras, och hur olika provtagningsmetoder påverkar analysresultaten / In a circular society that strives to close the cycle of resources, usage of rest material from one operation area to another plays a natural role. In operations connected to roadworks geological material are mainly handled. Geological material can contain sulfide minerals which can through oxidation produce acid. To ensure that the material can be used in constructions different prediction methods are used to estimate risks with the material. In this master thesis prediction methods has been studied on 10 different materials, the results shows that the studied prediction methods gives a big variation in results. 10 rock samples has been studied with the aim to investigate and discuss prediction methods for sulfidic rock. The rock samples had a sulfur content of 0,3 to 1,6 weight- %. The studied prediction methods included static test as Acid Base Accounting (ABA) and Net Acid Generation (NAGpH), mineralogical studies on the material. A kinetic test, humidity cell test (HCT) was started up in this project but not completed. Full rock chemistry and a simple leaching test was also performed on the material. The results from the prediction test on the material shows a large variation between the materials and when compared to different guideline values interpreted by different authorities. Determination of the neutralization and acid potential of the material also present a difference. There is a need to further investigate how the results from the studied prediction methods should be interpreted, and which tests are appropriate to use depending on where the material are planned to be used. How the sampling and sample preparation is preformed will also affect the result from prediction test. Therefore it´s important to investigate how representative sampling can be done to fulfill the purpose and how different sampling and preparation methods affects the results from analysis.
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Model for change in production systems triggered by environmental requirements : considerations, drivers, key factorsSannö, Anna January 2015 (has links)
Industry is a key player in the transition to a sustainable society where manufacturing companies need to respond to the challenges of environmental concerns in several ways. Still, even if several efforts have been made in practise and academia, more research within operations management is addressed in relation to implementing sustainable solutions. The management of change in production systems, such as energy efficiency, will be one of the important future areas for the industry. In accordance, the objective of the licentiate thesis is, by theoretical and empirical work, focused on developing a model to support the implementation of environmental requirements. Literature reviews as well as two empirical case studies have been conducted in order to explore the environmentally driven change. The first case study conducted is an retrospective multiple case study, including four cases studying the implications of implementation of technology and identifying key factors effecting the outcome of the change. The second case study is an international multiple study, including nine case companies. The study explores what needs to be considered, the drivers for initiating change as well as the key factors effecting the outcome of the change process. The studies conducted and the results are presented in five appended papers. The research identifies three important links for managing environmentally driven change: how the requirements are introduced, how and if the link between strategic and operational level has been considered and how the need for change is transferred to action and implementation. By providing a system approach for managing change, it also points out the importance of understanding the organisational abilities and maturity of the companies that influence the projects. The result points out sets of drivers as well as key factors, related to the organisational abilities, that are effecting the outcome. As future research the model, that is developed to support operations management in their work to implement environmentally driven change, needs to be validated in practise. In particular research on the personal commitment and the collaboration is addressed to be studied in relation to a systematic approach as well as how to balance the priorities during the implementation. / INNOFACTURE - innovative manufacturing development
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Utilizing CO2 from biomethane production : Sustainability and climate performanceCordova, Stephanie S. January 2023 (has links)
Biogas solutions offer many benefits for the environment and society, including organic waste treatment as well as being an enabler for energy and nutrient recovery. The products of anaerobic digestion are a biogas, which contains a share of 30 to 50% carbon dioxide (CO2) and 50 to 70% methane, and a liquid remanent, rich in nutrients. The biogas can be upgraded by removing the CO2 to increase the energy content, producing biomethane. At present, CO2 is considered a waste in biomethane production systems, and hence it is emitted into the atmosphere. Nevertheless, biogas upgrading technologies separate a pure-grade CO2 and, likewise, carbon capture processes, providing a pure CO2 flow that can be stored or utilized. Compared to storage, carbon capture and utilization (CCU) technologies deliver valuable carbon-based products required to sustain human activities. The valorization of green CO2 could aid the transition towards defossilization of the economy. Indeed, several CO2 utilization technologies could be incorporated into biomethane production systems, but there is still a limited understanding of the available alternatives and their potential impacts on biomethane systems. This thesis aims to investigate the integration of CO2 utilization technologies in biomethane production systems by revealing its potential, identifying alternatives, and assessing the impacts of the integration. Using Sweden as an example, scenarios of future biomethane production were employed to estimate the potential CO2 available for utilization. To complement the analysis, a qualitative approach made possible the identification of aspects that could affect CO2 utilization in biomethane production. Moreover, a multi-criteria analysis (MCA) framework was developed to identify relevant indicators for assessment and available alternatives for CO2 utilization. The research also includes a life cycle assessment (LCA) to evaluate the climate performance of relevant CCU alternatives in the biomethane production system. Results show that 160 kt of CO2 could be obtained from biomethane production in Sweden, which could potentially increase threefold from 2020 to 2030. The evaluation of alternatives for CO2 utilization includes environmental, technical, economic, and social criteria with sound indicators within an MCA framework. Indicators to evaluate each criterion provide valuable information to identify feasible and sustainable alternatives that can be integrated into biomethane plants. The identified alternatives with a high readiness level are additional methane through methanation, horticulture, mineral carbonates, fuels, pH control, bulk chemicals, and liquefied CO2 for direct use. The results provide information to decision-makers in relation to considerations to take before implementation, like energy requirements, the existence of regulations and standards, and uncertainty. In terms of the climate performance of biomethane with the inclusion of CCU alternatives, the results show a possible reduction of CO2 emissions that depends on the possibility of substituting fossil-based products. The investigated alternatives all result in lower emissions, but concrete curing and methanation using renewable hydrogen produce the best results. To conclude, the potential future increase of green CO2 from biomethane in Sweden creates opportunities to substitute fossil carbon in current applications and mature conversion pathways. Moreover, the inclusion of CCU in biomethane production contributes to reducing biomethane system emissions and diversifying its products. Possible alternatives of CCU that can be integrated into biomethane production systems in the short term include methanation and concrete curing. Other alternatives could be possible but present lower performance and higher uncertainties at the moment. / Biogaslösningar kan ge en mängd positiva miljömässiga och samhällsviktiga effekter, inklusive behandling av organiskt avfall och framställning av energi och näringsämnen. Produkterna från anaerob rötning är dels biogas, som består från 30 till 50% av koldioxid (CO2) och 50 till 70% av metan, dels en flytande rötrest med högt näringsinnehåll. Biogasen kan uppgraderas genom att ta bort CO2 för att öka energiinnehållet, och på så vis framställs biometan. CO2 ses för närvarande som en restprodukt i produktionssystemet och släpps därför vanligtvis ut i atmosfären. Tekniker för uppgradering av biogas liknar dock processer för infångning av CO2, där högkoncentrerade flöden av CO2 lagras (CCS) eller används (CCU). Till skillnad från lagring bidrar tekniken för CCU till att skapa produkter som behövs för att upprätthålla samhällsviktiga funktioner. Dessa valoriseringar av grön CO2 skulle kunna stödja övergången mot ett fossilfritt ekonomiskt system. Faktum är att det finns ett flertal tekniker som skulle kunna integreras i produktionssystem för biometan, men kunskapen om dessa tekniker och deras inverkan på biometansystemet är begränsad. Denna avhandling syftar till att undersöka integrationen av tekniska lösningar för nyttiggörande av CO2 vid framställning av biometan genom att påvisa dess potential, identifiera alternativa tekniska lösningar, och utvärdera integrationens följder. Med Sverige som exempel skapades scenarier för framtida biometanproduktion för att uppskatta mängden CO2 som skulle kunna tas om hand. Som ett komplement till dessa uppskattningar tillämpades ett kvalitativt tillvägagångssätt som identifierade aspekter som skulle kunna påverka CO2-användningen vid biometanproduktion. Dessutom utvecklades ett multikriterieanalytiskt (MCA) ramverk för att identifiera relevanta indikatorer för utvärdering och möjliga alternativ för CO2-användning. En livscykelanalys (LCA) tillämpades även för att utvärdera klimatprestandan för relevanta CCU-alternativ inom produktionssystem för biometan. Forskningsresultaten visar att 160 kt skulle kunna erhållas från biometanproduktion i Sverige. För Sveriges del finns det en potential att öka den insamlade mängden CO2 från biometan upp till tre gånger under perioden 2020 till 2030. I utvärderingen av de tekniska lösningarna inkluderas miljömässiga, tekniska, ekonomiska och regulatoriska kriterier för indikatorer inom ett MCA-ramverk. Dessa indikatorer användes för att utvärdera hur respektive kriterium bidrar till att identifiera realiserbara tekniska lösningar som kan integreras i biometananläggningar. De identifierade teknikerna med hög mognadsgrad är framställning av ytterligare metan genom metanisering, biomassa, karbonatmineral, bränslen, pH-värdesreglering, baskemikalier och flytande CO2 för direkt användning. Varje alternativ har dock faktorer som skulle kunna hindra implementering, såsom höga energikrav, lagstiftningar och standarder samt hög osäkerhet. När det gäller klimatprestandan för biometan med olika CCU-alternativ visar resultaten på en möjlig minskning av CO2-utsläpp som beror på möjligheten att substituera fossilbaserade produkter. Alla de undersökta alternativen resulterar i lägre utsläpp, men härdning av betong och metanisering med förnybar vätgas ger bäst resultat. Slutsatsen som dras är att det finns en stor potential i Sverige att framställa grön CO2 från biometan vilken skulle skapa flera möjligheter att byta fossilbaserade produkter i nuvarande tillämpningar. Införandet av CCU i biometanproduktion kan dessutom bidra till att minska biogassystemets utsläpp och diversifiera produktutbudet. Möjliga alternativ för CCU som kan integreras med biometanproduktionssystem på kort sikt inkluderar metanisering och betonghärdning. Andra alternativ kan också vara aktuella, men uppvisar för närvarande lägre prestanda och högre osäkerhet. / <p>Funding agency: The Kamprad Family Foundation</p>
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