ORWARE, an evolving systems analysis based computer model is used to assess the performance of different waste management options from a life cycle perspective. The present version of the model consists of different submodels for transport, treatment, and disposal of different types of liquid and solid wastes and recycling of materials. Flows between submodels are described by a vector of several substances of different relevance to the system. The model calculates emissions to water and air, amount of residues returned to arable land and energy flows using the tools of life cycle analysis (LCA) and substance flow analysis (SFA). In going in the direction of stringent environmental standards and policies, there is a need for maximizing energy recovery from waste for both environmental and economic benefits. Sweden has already experience of recovering energy from waste for district heating. Recovering energy not only of high value but also of higher quality from waste would be of interest. Hydrogen is one carrier of such energy. The possibility of using hydrogen from waste as a fuel in the transport sector would contribute in heading for creating a clean environment. In this thesis a new submodel for steam reforming of biogas recovered from an anaerobic digester is developed and used with other submodels within the ORWARE framework. Four scenarios representing alternative ways of energy recovery from the organic waste in Stockholm have been simulated to compare the associated energy turnover and different environmental impacts. Digestion of the organic waste and using the biogas to fuel cars is compared against steam reforming of biogas to hydrogen or thermal gasification of the waste and processing the product gases to hydrogen. In the latter two cases hydrogen produced is used in fuel cell cars. Avoided impacts of using the biogas and hydrogen are analyzed using the fourth scenario where the waste is incinerated to generate heat and electricity. Functional equivalence between scenarios is achieved by external supply of heat, electricity and petrol. While recognizing the uncertainties during modelling and simulation, it is possible to conclude that the results indicate that there is advantage of reduced environmental impact and high energy turnover in introducing the technologies of producing hydrogen from waste into the waste management system. Further and thorough investigation is recommended to come up with a sound and firm conclusion. Key words: Systems analysis, Life cycle analysis, Substance flow analysis, Waste management, Environmental impact, Steam reforming, Thermal gasification, Fuel cell vehicles, Hydrogen <img src="http://www.webforum.com/form/kthima/images/spacer.gif" /> / www.ima.kth.se

SammanfattningProdukter produceras idag i stor utsträckning för att tillfredsställa konsumenters behov varpåmiljöbelastningen eskalerar i takt med efterfrågan och produktionen som sker därefter. Lösningenpå problemet kan sammanfattas i ekodesign där miljöoptimering av produktutvecklingen skerutifrån ett helhetsperspektiv; råvaruutvinning, produktion, användning, återvinning, slutligtomhändertagande samt transporter.Teknik-konsultföretaget ÅF uppmärksammade detta problem hos svenska producenter ochstartade 2008 en intern sektion, EcoDesign center, som erbjöd sina kunder ekodesignrelateradetjänster. Utmaningarna och problemen hos kunderna har med tiden förändrats och för att centretska kunna erbjuda sina kunder relevanta tjänster, undersöks i detta arbete svenska producentersrelation till ekodesign idag.Syftet med arbetet har varit att kartlägga producenternas problem och utmaningar inommiljöanpassad produktutveckling och samtidigt utvärdera ÅF EcoDesign centers förutsättningaratt tillgodose sina kunder. Att utifrån denna kunskap komma med förbättringsförslag ochrekommendationer på hur centrets ekodesigntjänster kan optimeras har varit målet med arbetet.Resultatet visar att ekodesignarbetet inte är tillräckligt utbrett vilket främst beror på bristfälligefterfrågan av ekodesignade produkter. Kundefterfrågan är direkt kopplat till ekonomiskaincitament, företag drivs i vinstsyfte och utan en efterfrågan kommer ekodesignarbete inteimplementeras. Producenterna har inte insett eller förstått den ekonomiska potentialen medmiljöeffektiv produktutveckling och tror det är dyrt och tidsödande. En orsak till detta kan varabristen på enkla ekodesignverktyg, då de flesta existerande verktyg kräver experter.Kunskapsbristen är ett faktum, vilket producenterna själva ser som ett av de största hindren förimplementering av ekodesign i produktutvecklingsprocessen.ÅF:s EcoDesign center bör satsa på en inledande ekodesigntjänst som kartlägger vad för typ avekodesigntjänst deras kunder behöver hjälp med. Denna tjänst ska fungera som en inkörsport tillövriga ekodesignområden som EcoDesign center rekommenderas att satsa på i framtiden; PRS(Product Regulatory Support), strategi, eco screening, utbildning, tjänstedesign ochmarknadsföring. / Products are currently produced to satisfy customer needs to a large extent whereupon theenvironmental impact escalates due to the demand and production. A solution to the problemcan be summarized in the term eco design where the environmental optimization of a producthas a holistic perspective, including everything from raw material extraction, production, uses,recycling, disposal and transport.ÅF, a technology consulting firm, drew attention to this problem and started EcoDesign centerin 2008, an in-house section where they offered their customers eco design related services. Thechallenges and problems in their customers needs have changed over time and understandinghow the center should provide their customers with relevant service is investigated in this thesis.The aim of the thesis has been to identify producers’ problems and challenges with greenproduction and at the same time evaluate EcoDesign center's prerequisites to satisfy theircustomers’ needs. Based on this knowledge, the aim has been to come up with suggestions andrecommendations on how the center can optimize their eco design related services.The result shows that the eco design work is not sufficiently widespread, mainly due to a poordemand for eco designed products. Customer demand is directly linked to economic incentives,companies run for profit and without a demand an eco design work will not be implemented.Producers have not realized the economic potential of eco effective products and think it isexpensive and time consuming. One reason can be the lack of simple eco design tools, sinceexisting tools require expertise. The lack of knowledge is a fact, which the producers consider tobe one of the biggest obstacles to implement eco design in the product developing process.EcoDesign center should invest in an initial eco design service that identifies in which types ofeco design areas their customer needs help. This service will act as a gateway to other eco designservices offered at the center. In the future, EcoDesign center is recommended to focus on thefollowing, eco design related work; PRS (Product Regulatory Support), strategy, eco screening,education, service design and marketing.

Vid byggnationer av hallbyggnader är konstruktioner av stål eller betong vanliga. Klimatpåverkan som härleds till respektive byggnadssystem är undersökta i detalj, material kontra material eller byggnadsdel mot byggnadsdel. Vår undersökning ger ett resultat av klimatpåverkan för byggnadssystemen i sin helhet med byggnader som uppfyller samma krav. Denna studie utmynnar i en jämförelse av antalet CO2-ekvivalenter respektive vad byggnadssystemen bidrar med per m2. Genom att studera en befintlig betongbyggnad och dimensionera en stålbyggnad utefter samma förutsättningar. Dimensionering innefattar: pelare, upplagsplåt, fotplåt, vindkryss och brandgips för pelare, stommen bekläds med stålelement från Paroc. Utifrån dessa mängder beräknas klimatpåverkan med hjälp av EPD:er som sammanställts och beräknats i Excel. Detta arbetssätt säkerställer en relevant och rättvis jämförelse. Vår studie visar att ett självbärande betongelement bidrar med 83,80 kg CO2-ekv/m2 och stålsystemet bidrar med 60,59 CO2-ekv/m2. De skeden i livscykeln som bidrar med störst skillnad mellan systemen är: Produktskede (A1-A3) och byggproduktionsskede (A4-A5). / In the construction of hall buildings, steel or concrete constructions are common. The climate impact that is derived from the respective building system is examined in detail, material versus material or building part against building part. This study provides a result of the climate impact for the building systems as a whole, with buildings that meet the same requirements. This study results in a comparison of the amount of CO2-ekv each building systems contribute per m2. By studying an existing concrete building and dimensioning a steel building according to the same conditions. Dimensioning includes: pillars, support plate, foot plate, wind cross and fire plaster for pillars, the frame is clad with steel elements from Paroc. Based on these quantities, the climate impact is calculated with the help of EPDs, compiled and calculated in Excel. This approach ensures a relevant and fair comparison. Our study shows that a self-supporting concrete element contributes 83.80 kg CO2-ekv/m2 and the steel system contributes 60.59 CO2-ekv/m2. The stages in the life cycle that contribute the greatest difference between the systems are: Product stage (A1-A3) and construction stage (A4-A5). / <p>Betyg 2021-06-04</p>

I Sverige används många olika interiöra golvmaterial i offentliga byggnader. Studien har undersökt fyra interiöra golvmaterial, keramik, enomer, massivt furu och linoleum. Dessa material är vanligt förekommande i svenska offentliga miljöer och de jämfördes ur ett livscykelperspektiv. Studien undersökte materialens olika livsskeden, från produktion till slutskede och omfattade materialens totala GHG-utsläpp för en referensbyggnad med en livslängd på 75 år, belägen i Växjö.Denna fallstudie visar att en byggnads klimatpåverkan går att minimera vid val av interiört golvmaterial. Keramik är att rekommendera i fuktkänsliga utrymmen då klimatpåverkan är 38 % minder och linoleum rekommenderas i allmänna utrymmen då klimatpåverkan är 20 % mindre. Det finns ytterligare möjlighet att minimera klimatpåverkan genom att använda trägolv i utrymmen med mindre folk i rörelse. / In Sweden, lots of different interior flooring materials are used in public buildings. This study examines four interior flooring materials, ceramics, mineral based, solid pine floor and linoleum flooring. These materials appear regularly in public buildings in Sweden and are compared to each other in a life cycle assessment perspective. The study examines the materials different life stages from production to its end of life and included the materials GHG-emissions for a reference building with a lifespan of 75 years in Växjö, Sweden.This case study shows that a buildings climate impact can be minimized through choices for interior flooring materials. Ceramics are to recommend in areas sensitive to moisture, do to 38 % less climate effect and linoleum are to recommend more public areas do to 20 % less climate effect. Further possibilities to minimize climate impact is through use of massive pine flooring in areas with low traffic.

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Purpose: This project compares two foundation insulation materials: cellular plastic and cellular glass. Currently, cellular plastic is the most used material for foundation insulation. While cellular glass is not widely utilized. Its disadvantage lies in its higher cost, which makes contractors prefer the cheaper alternative, cellular plastic. Cellular glass exhibits exceptional properties, including its notable attributes of high load-bearing capacity and superior moisture resistance. The aim of this study is to demonstrate how material savings can be achieved by using cellular glass instead of cellular plastic in the load-bearing parts of the foundation. In addition to cost savings, the study also includes the analysis of carbon dioxide emissions during the production of these materials and specific heat losses through the material. Method: To facilitate understanding of the study, two different buildings were visualized: a two-story building and a seven-story building. The choice of different building sizes aimed to investigate how different loads on foundation insulation affect insulation material costs, carbon dioxide emissions, and the heating requirements of the buildings. Revit and AutoCAD were used for modelling and visualization. Flixo and manual calculations were employed for energy calculations, while manual calculations were used for structural calculations. One Click LCA Software was used to determine the carbon dioxide emissions for the different foundation insulation scenarios. Results: The study suggests that for buildings with lighter loads, cellular plastic is a cost-effective choice, while a hybrid insulation approach combining cellular glass and cellular plastic is the best option considering environmental factors. However, for buildings with higher loads, cellular glass outperforms cellular plastic both in terms of economics and the environment. Nonetheless, a combination of cellular glass and cellular plastic remains the most favourable choice among the three scenarios, as energy losses are approximately the same due to the similar thermal conductivity values of these materials. Conclusion: Hybrid insulation proves to be the most advantageous option in terms of both the environment and economics for both types of buildings studied: the two-story residential building and the seven-story residential building. By using cellular glass F for the load-bearing structures and cellular plastic EPS S60 for the ground slab, effective insulation is achieved. The use of cellular glass F results in material savings, such as cellular plastic XPS 700, which has half the load-bearing capacity of cellular glass F. Additionally, reducing the use of extra concrete for load-bearing foundation constructions decreases the load on the foundation insulation material.

<p>To accurately estimate the potential recovery of metals from electronic devices, various tools such as mass flow analysis, dynamic models, and forecasting models have been employed. However, the reliability of the model-generated outputs hinges on the accuracy of the input data. To ensure accurate data collection, it is imperative to examine and compare different methodologies. Although surveys have conventionally been used in information and telecommunications technologies to gather consumer information, their validity is seldom contrasted with alternative methods due to the lack thereof. In response, a new mixed methodology has been developed to obtain primary consumer data through tangible information, offering new avenues for data acquisition. The methodology involves quantitative and qualitative approaches taking direct physical measurements (dimensions, weight, and quantity) of devices and including a ten question semi-structured interview to discussed consumer devices use, stock and transfer patterns, composition changes of the electronic devices, and disposal behavior. As a result, it was found new methodology measured 79% of the devices directly at laboratories and 21% of the remaining devices were self-reported by the participant. The devices on consumer stage frequently have the same type and number of components as fabric and a positive difference of about 17.99 g compared with the mass reported by fabricants or literature. The sequential steps undertaken by participants in the new methodology to acquire consumer-stage data offer distinct advantages over surveys, particularly in capturing a more comprehensive inventory of devices in storage.</p><p>Additional results indicate that the proposed methodology can provide valuable insights into the stock of electronic devices. Nevertheless, further research is required to understand the implications of surveys versus direct measurements in accurately representing mass flows during the user stage. Additionally, the relevance of external power supply or charging systems on storage will be explored as part of the supplementary findings. By improving the accuracy of metal recovery estimation and exploring more effective data collection methods, we can optimize closed-loop projects and contribute to sustainable resource management.</p>

In the production of glass, the addition of more cullet to the batch of glass and the reduction of the thickness of glass are means to reduce energy consumption and raw material usage. This contributes towards improved energy efficiency targets of the European Union. This thesis investigated the energy consumed for the process of strengthening thinner glass as well the environmental implications of thinner and stronger compared to conventional glass across the life cycle of glass. The life cycle phases also included a recycling phase where 70% of the used glass was recycled with the remaining 30% being landfilled. The functional unit selected for this study was 1m2 of SLS glass, 4mm thick, with an average light transmittance of 91%. This corresponds to 10kg of clear float glass as per general rule. The findings of this thesis showed that one of the major contributing factors to high energy consumption in the melting phase of SLS glass is low efficiency of the furnace; this led to significant energy losses in the production of SLS glass. Recycling of flat glass, at a 70% rate, led to a 12% reduction in total global warming potential, a 10% reduction in the Acidification Potential, a 13% reduction in the Eutrophication Potential in marine environs, and a 7% reduction in the Eutrophication Potential in terrestrial habitats. The chemical and thermal strengthening process consumed 2.24 and 2.37 kWh/m2 respectively. The consequential impact of this is dependent on the source of the electricity for the strengthening processes. It was concluded that the energy used for the strengthening of the thinner glass is considerably less than the energy used in the production of a conventional glass that satisfies the same strength parameters.

<p>In the Central Hardwood Region, the quantity and quality of hardwood timber critically depend on forest management decisions made by private landowners, since they hold the largest share of woodlands, some of which are plantations. These plantations are in a unique and critical position to provide much-needed hardwood resources. However, there is a lack of research and tools enabling rigorous assessments of profitability of long-term investments in hardwood plantations. Partially due to this, the majority of these privately held plantations remain unmanaged.</p> <p>This study aims at providing scientific evidence and tools to help promote forest management on hardwood plantations held by private landowners. To this end, I demonstrate in Chapter 1 an economic-modeling approach that minimizes establishment costs while ensuring free-to-grow status by year 5, and crown closure by year 10. Using temperate hardwoods such as black walnut and red oak as focal species, I find a black walnut plantation can attain crown closure in year six at the lowest cost ($4,540/ha) with 6 feet x 7 feet spacing, herbicide application for the first year, and fencing. For red oak, the minimum-cost option ($5,371/ ha) which achieves crown closure in year 10 requires a planting density of 6 feet x 7 feet, herbicide application for the first three years, and fencing. Modelling uncertainty in growth and mortality in a stochastic counterpart shifts optimal solutions to denser plantings for black walnut; planting more trees is, thus, risk mitigative. Based upon these research outcomes, I identify the tradeoffs between efficacy of treatments towards establishment success viz a viz their relative costs which serve as a solid foundation for the assessment of subsequent management strategies.</p> <p>Next, in chapter 2, I first calibrate growth, yield, and crown-width models for black walnut trees with existing and new tree measurements on selected Hardwood Tree Improvement and Regeneration Center (HTIRC) plots. Using spatial information on trees, I develop an individual tree level thinning model and simulate their post-thinning growth and yield. Significant predictors of annual diameter growth between years 10 to 18 include the initial tree DBH, forest edge effects, distance-dependent neighborhood competition, and tree age. Significant edge effects exist up to 3 rows and 3 trees from the non-forested edge. A tree on the perimeter rows grows 0.30 cm (0.12in.) in DBH more per year than the interior trees, between years 10 to 18. Next, I dovetail my results from the spatially explicit thinning model with the USFS Forest Vegetation Simulator (FVS) to understand the impacts of different scenarios of planting densities, site productivities, thinning treatments, and expected yields (as percentage of the total volume) of veneer sawlogs to quantify the growth and profitability from the mid-rotation until the final harvest. To support the attendant financial analyses, I incorporate risk into these projections by simulating stochastic windthrows based on certain assumptions. My projections suggest that, without the threat of windthrow damage, the net present day value (NPV) could exceed $4,900 per acre on the highest quality sites (SI =100) and high densities at planting (6 feet x 6 feet), assuming 10% or more of final volume was veneer and using a 3% discount rate. In contrast, under simulations of probable windthrow disturbances from mid-rotation to final harvest, the chances that standing timber value at harvest exceeds $5,000 per acre are 43.13% for a 96- and 90-year rotation and increase to 45.48% for 75 and further to 56.04% for 60.</p>

Syftet med detta examensarbete var att utveckla ett hållbart ersättningsmaterial till akrylnitrilbutadienstyren plast (ABS), genom att applicera principerna för grön kemi och teknik. ABS är en icke-nedbrytbar plast som till exempel används i slagtåliga produkter för hyttinteriörer. Att utveckla ett nytt material baserat på en kravspecifikation med en specifik produkt i åtanke är av stor betydelse då en initial teoretiska utvärdering kan ge resultat som driver ytterligare innovation och säkerställer en god överensstämmelse med förväntningarna på produkten. Baserat på den genomförda litteraturutvärderingen och kravspecifikationen för produkten valdes polylaktid (PLA) som matrismaterial och blandades med nanofibrer av lignocellulosa (LCNF) och naturgummi (NR), där maleinsyraanhydrid (MA) användes som kompatibilisator. Denna modifieringsstrategi syftade till att förbättra PLAs styrka och minska dess sprödhet. Flera olika parametrar undersöktes, vilka inkluderar olika torkningsmetoder för LCNF:en och olika metoder för MA tillsats före bearbetningen av blandningen. Termisk analys av blandningarna visade att tillsatsen av LCHF och NR inte påverkar nedbrytningstemperaturen för PLA-matrisen i någon större utsträckning, men att kristalliniteten påverkades av dem och de olika behandlingsmetoderna. Styvheten hos de PLA-baserade materialen var likvärdig ABS, medan elasticitet var generellt likvärdig PLA och där tillsatsen av naturgummi förbättrade materialens deformationskapacitet. SEM bilder indikerade att de tre komponenterna var kompatibiliserade, då fibrösa strukturer och sammanflätade nätverk av LCNF och NR i PLA-matrisen kunde observeras. SEM bilderna visade också att NR agglomererade då stora agglomerat och porösa strukturer uppstod, vilket understryker vikten av att optimera framtida blandningsstrategier. En livscykelbedömning (LCA), enligt en vagga-till-graven metod, förväntas visa lägre koldioxidutsläpp för det föreslagna alternativet jämfört med ABS tack vare tillämpningen av principerna för grön kemi vid produktutformningen. Detta bekräftar den ursprungliga hypotesen om en ökad miljövänligheten hos PLA-baserade ersättningsmaterial jämfört med ABS. / This thesis aims to develop sustainable replacement for Acrylonitrile Butadiene Styrene (ABS) in high-impact applications within construction equipment’s Cab interior. Adhering to the principles of Green Chemistry and Engineering, the study focused on developing and accessing an environmentally friendly substitute for ABS, a commonly used non-biodegradable plastic. Investigating novel materials with a tailored requirements list is vital in materials science and engineering. Theoretical approaches can yield results which drive further innovation, ensuring comprehensive alignment with application expectations through a holistic approach to address critical factors. Following this guideline, the chosen alternative was Polylactide (PLA), fortified with a blend of lignocellulose nanofibers (LCNFs) and natural rubber (NR) at a 10 wt.% concentration, with the addition of Maleic Anhydride (MA) as a compatibilizer. This modification strategy aimed to enhance PLA's strength and reduce its brittleness. The investigation encompassed various parameters, including different LCNF drying methods and variations in additive treatment before melt-mixing with PLA. The outcomes from thermal analysis indicated that the inclusion of reinforcements does not significantly affect the degradation temperature of the PLA matrix. Crystallinity, on the other hand, was found to be influenced by the presence of lignocellulose reinforcements and natural rubber, with intriguing nuances emerging from the interplay of these components and different treatment methods. PLA-based alternatives performed similarly to low grade ABS and had similar stiffness levels. In terms of elasticity, most materials behaved similarly to neat PLA, but the addition of natural rubber enhanced their deformation capacity. Successful compatibilization between lignocellulose reinforcements, natural rubber, and PLA was assumed from the observed fibrous structures and interwoven networks within the PLA matrix. Additionally, the presence of aggregates and porous structures highlighted the challenges posed by rubber agglomeration. Finally, the observation of larger agglomerates beyond typical interphase sizes raised concerns about brittle behavior, emphasizing the need for optimizing blend toughening strategies. The input for a Life Cycle Assessment (LCA), following a cradle-to-gate approach, is anticipated to show lower carbon emissions for the proposed alternative in comparison to ABS due to the principles of Green Engineering applied in the product design, denoting the environmental viability of the PLA-based substitute.