Dissertations / Theses on the topic 'Circular Economy for Plastics'

El sector de los plásticos está experimentando un importante cambio de dirección hacia la sostenibilidad y la innovación. El modelo de Economía Circular como alternativa al modelo tradicional de producción, uso y vertido está generando un gran impacto en nuestra sociedad. La recuperación y reciclaje de materiales se ha convertido en una etapa importante dentro del sector y se prevé que la demanda de productos reciclados aumente en los próximos años. Sin embargo, el sector del reciclaje no está preparado para cumplir la creciente demanda, sobre todo, en cuanto a la calidad de los materiales. En esta tesis se han estudiado los métodos de tratamiento de residuos plásticos desde tres puntos de vista: medioambiental, tecnológico y calidad del producto final. Se ha dedicado un capítulo de la tesis para profundizar en cada uno de estos temas. Para estudiar el impacto medioambiental se ha realizado un análisis de ciclo de vida comparativo entre un proceso de reciclaje innovador alineado con los principios de la Economía Circular y dos métodos de tratamiento de residuos tradicionales. Desde el punto de vista tecnológico, se ha estudiado el proceso de eliminación de agua durante el reciclaje de plásticos flexibles con el objetivo de optimizar parámetros y reducir el consumo de energía. Por último, se llevado a cabo un estudio de las sustancias orgánicas semivolátiles presentes en plásticos reciclados, ya que éstas pueden suponer un riesgo para la salud de los consumidores si se utilizan en aplicaciones de alto valor añadido. Además, se ha realizado un estudio exhaustivo del estado del arte de los sistemas de gestión de residuos plásticos, prestando especial atención a los plásticos flexibles debido a que su tasa de reciclaje se encuentra por debajo de los plásticos rígidos. Como resultado se han identificado los puntos débiles y se han marcado directrices para impulsar la transición hacia la Economía Circular.

The awareness on raw material scarcity and environmental issues has globally stimulated interest into the re-design of products, processes or services, maximizing prevention, reuse and recycling rates. Within this context, plastic represents a key material. In particular, plastic packaging is a priority issue, accounting for the 40% of the European converters demand and about 60% of post-consumer plastic waste. Nowadays, less than 30% of collected plastic waste is recycled, while landfilling and incineration rates of plastic waste remain high, approximately 27% and 41% respectively. The EU Commission is currently hardly working on this issue: the recent EU Plastic Strategy sets very ambitious goals for plastics sustainability. This background topic is the key point of the master thesis. The study starts with mapping the best practices on plastic recycling and prevention, following the entire plastic packaging value chain. Adopting a multi-criteria perspective, legislative, economic and technical, technological and environmental framework of good practices and criticalities is outlined, in order to assess the current state of innovation on circular economy for plastics. The overview on levers and barriers for plastic circularity allows to design a new set of circular economy indicators suitable to be applied on plastic packaging sector. As good practices, eco-design principles are adopted in order to delineate an assessment tool able to identify plastic packaging sustainability and circularity. Moreover, the compliance with the regulatory framework and possible economic advantages are verified. Therefore, the final goal of the study is to identify practical suggestions which can be converted into a set of indicators for measuring plastic packaging circularity, delineating criticalities and possible improvements for boosting the sustainable transition of the entire sector.

In the last three decades, the increased use of plastics is rapidly becoming a global environmental issue, resulting in growing landfills and pollution of air and water. The automotive industry, as a major demander of plastic materials, is starting to take responsibility with promised sustainability actions. One action relates to the concept of circular economy and closed loop thinking through the implementation of recycled plastics. However, the barriers of such implementations are still undiscovered, with research missing out on the challenges of strategic and business perspectives. The aim of this thesis is to asses and understand the challenges connected to implementing recycled plastics in the automotive industry, and to provide strategic recommendations. In order to identify the challenges, an empirical case study was carried out collecting data through 10 interviews with suppliers throughout the plastics refining chain. A cost calculation was also included, to highlight the economic potentials of recycled plastics. The findings address 6 themes as barriers for implementing recycled plastics in the automotive industry: economic, organizational, infrastructural, interactional, design and technical barriers. The barriers shed light on the challenges connected to the implementation of recycled plastics and concludes that the rate of recycled plastics in a car can be increased, which also increases sustainability and circular thinking. However, the rates could be further improved if managers were to consider the existing barriers when implementing higher rates of recycled plastics in their components.

The consequences of the linear economy of plastic production has started to show. Media reports of "plastic seas," beaches full of waste, and habitats and environments destroyed. The question on how to make plastic production more circular have been a hot topic. Every year 311 million tonnes of plastic gets produced around the world. The plastics that can be recycled are thermoplastics. 70% of all produced plastic is made from five different plastic materials, PVC, PET, EPS, PP, and HDPE. Of the total of 311 million tonnes 87 million tonnes of that plastic is plastic packages for household consumers. Of that 87 million tonnes 32% of that is never collected, ending up in the oceans. Sweden is doing well compared to most countries, 99% of all plastic in Sweden is collected. The number is much thanks to all the regulations, recycling organs, and producer requirements that are active in Sweden compared to many other countries. This report is going to point out some important challenges and its solutions to move towards a globally circular economy. Sweden still faces challenges. Of all plastic collected only 50% goes into recycling while the other 50% ends up for incineration to energy recovery, to warm up houses and give electricity to cities. There are four different methods of recycling in facilities today. Closed - loop Open - loop Chemical recycling Energy recovery through incineration Closed - loop recycling is when the recycled product ends up as the same product after the recycling process while open - loop is when something gets recycled to a plastic product with a lower value than the original product. Chemical recycling is when chemicals in the plastic are extracted and recycle these, usually for fuels. Energy recovery through incineration is when plastic waste is burnt down to recover the energy stored in the plastic. The most common recycling methods in Sweden are open-loop recycling and energy recovery through incineration. One plastic container differs from the rest. The PET - bottles. Of all plastic bottles 85% are collected and recycled in Sweden much thanks to the deposit-refund system available in Sweden. Plastic bottles often follow a process called URRC process, which is a full process from collecting plastic bottles to selling clean plastic flakes that can be renewed to new plastic bottles. Sweden is building the largest recycling facility in Europe, with a technology called "Near-echnology" which is a technology with Near-infrared light to efficiently sort out coloured and clear plastic as well as type of material and chemical compound. This technology will help the facility sort out more than 50% plastic waste compared to other facilities in Europe, an essential step toward a circular economy. Another meaningful action is in the form of global and international producer recommendations, where strict regulation regarding production, design, and materials are agreed upon that favours packaging improving its recycling abilities. These regulations come from the recycling companies such as Returpack and Plastkretsen.
Konsekvenserna från en linjär ekonomi inom plastproduktion har börjat att visas. Media rapporterar om "plast hav", stränder fulla med avfall med habitat och miljöer förstörda. Frågan hur man kan göra plastproduktionen mer cirkulär har varit ett hett debatterat ämne. Varje år produceras 311 miljoner ton plast runt om i världen. Plasten som idag går att återvinna kallas Termoplaster. Av de plasterna består 70% av dessa olika plastmaterial, PVC, PET, EPS, PP och HDPE. Av all tillverkad plast är 78% miljoner ton plastförpackningar varav 32% av det som tillverkas hamnar i haven. Sverige sköter sig bättre än många andra länder när det gäller uppsamling av plast plockas 99% upp. Denna siffra är mycket tack vare de lagar, förordningar och återvinning organ som existerar i Sverige jämfört med andra länder. Detta arbete kommer att fokusera på de utmaningar som uppkommer när man ska röra sig mot en mer cirkulär ekonomi och de lösningar som finns för att klara av utmaningarna. Sverige står för ett antal utmaningar. Av all plast som samlas in i Sverige går 50% till återvinning av materialet medan 50% går till förbränning för att få ut energi, för att värma hus och generera energi till städerna. De fyra vanligaste metoderna som används i återvinning av plast idag är. Closed - loop Open - loop Kemisk återvinning Förbränning för energi Closed - loop är en återvinningsmetod som betyder att när en produkt återvinns kommer den komma ur cykeln som samma eller liknande produkt, detta kan jämföras med open - loop där produkten återvinns till ett material med sämre kvaliteter. I kemisk återvinning återvinner man kemikalierna i plasten. Vanligt är att utvinna kemikalier för att sedan använda som olika bränslen. Den sista vanligaste metoden är förbränning av plast för att få ut energin som finns lagrad i plasten. De vanligaste metoderna i Sverige är idag open - loop samt förbränning. En typ av plastförpackning skiljer sig dock mot mängden, PET - flaskor. Av alla flaskor återvinns 85% till en ny plastprodukt. Detta är mycket beroende på det välfungerande pantsystem som finns i Sverige. Insamlade plastflaskor följer i Sverige en process som heter URRC - processen. Denna process följer allt från insamling av plastflaskor till försäljning av klara plastflingor som kan återvinnas till bland annat flaskor. Sverige bygger även Europas största återvinningscentral för plastinsamling. Med en ny teknologi som de kallar "Near- Technology" som bygger på Near - infrarött ljus´ skall öka precisionen på sortering av plasten. Från material, färg och kemisk uppsättning. Potentialen är 50% mer sorterad plast än någon annan anläggning i Europa. Andra nödvändiga åtgärder för att skapa en cirkulär ekonomi är i form av strikta förordningar, skärpa lagar och att plastproducenter följer de rekommendationer som kommer från till exempel, Returpack och Plastkretsen.

Plastic materials are widely used in different applications by the industry. Given its different properties, there is a wide range of utilization opportunities. From an environmental perspective, some of these properties imply a challenge for the recycling of these materials. Over the years, Deposit Return Systems (DRS) have been formulated and developed aiming to increase recycling rates of these materials. This study aims to determine if the expansion of the DRS for plastic materials can tackle current technical and logistical challenges that hinder the recyclability of these materials in Sweden. Specifically, it maps the actors and processes involved in the plastic value chain, identifying current challenges that affect the recyclability of the materials but also opportunities to increase the rates of recycling. Finally, after studying and characterizing different DRS implemented around the world, recommendations are given on what types of DRS expansions could be suitable for the Swedish context.  Based on a literature review the current Swedish plastic value chain is studied and technical and logistical challenges are identified along it. Simultaneously the study investigates technological developments and innovations intended to improve the recyclability of the plastic materials. One of the main challenges identified is the fragmentation along the value chain, which is a barrier to utilizing the system to its full potential in terms of generating recyclable material as well as establishing well-functioning value regeneration of the materials. This information is useful to discussions on a future expansion of the DRS in Sweden.  Likewise, after describing the different DRS options studied, recommendations are given for its implementation. The analysis concludes that given the current context that includes the start-up of a large sorting facility, the most promising option would be to opt for a design & sorting incentivizing DRS that is relying on the conventional waste management and does not require major investments in infrastructure. Other options are not discarded, but it is recognized that these may be more costly or more technologically demanding, also requiring more research to give an assertive assessment.
Plastmaterial används ofta i olika applikationer av industrin med tanke på dess olika egenskaper. Miljömässigt innebär några av dessa egenskaper en utmaning för återvinning av dessa material. Under åren har pantsystem (Deposit Return Systems (DRS)) formulerats och utvecklats för att öka återvinningsgraden för dessa material. Denna studie syftar till att avgöra om expansionen av DRS för plastmaterial kan hantera nuvarande tekniska och logistiska utmaningar som hindrar återvinningsbarheten av dessa material i Sverige. Specifikt kartlägger uppsatsen de aktörer som är involverade i plastvärdekedjan och identifierar nuvarande utmaningar som påverkar materialens återvinningsbarhet, men också möjligheter att öka återvinningsgraden och slutligen efter att ha studerat olika DRS implementerade runt om i världen ges rekommendationer om huruvida vissa av dem är lämpliga för det svenska sammanhanget.  Baserat på en litteraturstudie studeras den nuvarande svenska plastvärdekedjan och tekniska och logistiska utmaningar identifieras längs den. Samtidigt undersöker studien teknisk utveckling och innovationer som syftar till att förbättra återvinningsbarheten hos plastmaterialen. En av de viktigaste utmaningarna som identifierats är fragmenteringen och underutvecklingen längs värdekedjan, särskilt återvinningssektorn. Denna information är användbar för att fastställa trender i branschen men är också viktig att tänka på i formuleringen av en expansion av DRS i Sverige.  På samma sätt, efter att ha beskrivit de olika DRS-alternativen, ges rekommendationer för dess genomförande. En slutsats är att med tanke på det nuvarande sammanhanget som inkluderar start av en stor sorteringsanläggning är det mer genomförbart att välja en modell för DRS som integreras i nuvarande kommunala avfallshantering och inte kräver större investeringar i infrastruktur. Systemet ska bygga på att skapa incitament för återvinningsbar design såväl som för ytterligare sortering. Andra alternativ avfärdas inte, men dessa kan vara mer kostsamma eller mer tekniskt utmanande och kräver mer forskning.

Il corpo dell'elaborato è lo studio e l'applicazione del 'Life Cycle Assessment' (LCA) per un granulo di PVC. La prima parte del lavoro è una valutazione dell'industria odierna della plastica, in particolar modo del PVC, dall' origine della risorsa, attraverso tutte le fasi industriali fino al prodotto finale. Seguendo viene presentato il carattere poco sostenibile dell'industria in questione e possibili soluzioni tecniche attualmente utilizzate o previste. Mediante l'uso del GaBi software è stato possibile applicare la metodologia dell'LCA, analizzando tecnicamente l'impatto ambientale del prodotto. Infine, l'ultima parte del lavoro comprende una sezione dedicata al 'Cost-Benefit Analysis', utilizzato per quantificare il rapporto tra i costi e i benefici dell'industria.

The choice of policy design has crucial implications for a policy’s efficiency. Plastic as a material is an important issue because of its fossil origin and because it often ends up as litter and spreads microplastics. Consequently, policies regarding plastic are vital to examine to understand how we can reduce the environmental consequences of plastic. This study has examined the design of the plastic carrier bag policy and especially focused on the choice of policy instrument, the actors involved, and if the desired change in behaviour occurred. By utilising Schneider and Ingram’s policy design theory, and Howlett and Vedung’s works on policy design and policy instruments, the study built an analytical framework to examine the plastic carrier bag policy. The result showed that the design of a policy was largely dependent on who governed, reflecting the government’s political culture, aims, and goals. The outcome of the policy showed that tax as an economic instrument was efficient in changing the public’s behaviour in the use of plastic carrier bags.

Il riciclo della plastica è una soluzione adottata già da decenni che esprime a pieno il concetto di economia circolare: si riutilizza la plastica come materia prima seconda, in modo da evitare lo spreco di risorse per produrre materiale vergine. In questa tesi si vuole analizzare a fondo il di riciclo dei materiali polimerici, evidenziandone le criticità che lo rendono un processo di riciclo “difficile” se messo a confronto con quello di altri tipi di materiali. Con la terminologia riciclo della plastica si sottintendono in realtà più varianti di lavorazioni dei polimeri, di cui quello più affermato ed utilizzato nella quasi totalità dei casi è il meccanico. Nonostante da anni il riciclo meccanico sia il metodo prediletto per riprocessare la plastica a fine vita, vi sono alcuni ostacoli che possono rendere la lavorazione inefficiente. La selezione dei materiali e i suoi costi, il lavaggio e le complicazioni dovute a materiali organici presenti nei flussi, la cernita per colore e le difficoltà ad essa legate e la degradazione del materiale ne rappresentano alcuni. Alcune pratiche costose di pre-processamento possono essere evitate, invece, da una tecnica che si sta sviluppando recentemente: il riciclo chimico. Quest’ultimo consiste in una depolimerizzazione dei materiali per ottenere i monomeri di partenza che lo costituiscono, che hanno la stessa valenza di monomeri di materiale vergine. Il fattore dell’alta qualità dell’output, assieme alla tolleranza di materiali organici presenti nei rifiuti, sono delle caratteristiche che lasciano ben sperare in evoluzioni future di questa tecnica. I costi, la complessità delle reazioni e il fatto che siano difficili da realizzare in larga scala, ne ostacolano, per ora, l’impiego, ma resta comunque un’eccellente soluzione complementare al riciclo meccanico.

Studien baseras på en målkonflikt mellan att vilja ha en giftfri miljö och samtidigt sträva mot ett mer cirkulärt samhälle. Polyvinylklorid (fortsättningsvis PVC-plast) kan innehålla farliga ftalater som i för stor mängd kan vara skadliga för hälsa och miljö både under användning och återvinning. REACH-förordningen reglerade ftalaterna DEHP, DBP, BBP och DIBP i PVC-plast år 2015 genom att kräva tillstånd för att få använda dessa ftalater vid tillverkning av produkter inom EU. Den förändrade material-kompositionen leder till att den nytillverkade PVC-plasten skiljs från den äldre som producerades innan lagförändringen 2015. Målet att sträva mot ett mer cirkulärt samhälle genom att återvinna mer PVC-plast hindras av målet att skapa en giftfri miljö eftersom den äldre PVC-plasten innehåller förbjudna ämnen. Studiens syfte är att undersöka hur denna målkonflikt påverkar återvinningen av PVC-plast inom byggsektorn.  För att besvara syftet har kvalitativ metod använts och sex intervjuer har genomförts med personer från Innovations- och kemiindustrierna i Sverige (fortsättningsvis IKEM), Tarkett, Byggföretagen, Bolon, Naturvårdsverket, IVL Svenska Miljöinstitutet och BASTA.  Resultatet av studien är att ingen av de intervjuade anser att plasten varken måste ersättas eller förbjudas. De anser snarare att politiken och de vetenskapliga belägg som finns måste diskuteras mer samtidigt som kraven på miljömärkt PVC-plast måste öka för att kunna säkerställa en hållbar hantering. För att kunna öka den cirkulära ekonomin är ett förslag att implementera loggböcker där byggföretagen kan redogöra för det material som används under byggskedet, detta skulle då öka spårbarheten och därmed möjligheterna för återvinning.
The study focuses on the emerging policy conflict between a non-toxic or a toxic-free environment and a circular economy. Polyvinyl chloride (PVC plastic) contains phthalates which in excessive amounts can be dangerous to the health and the environment. Problems arise when PVC plastic is to be recycled and these phthalates spread into nature. The REACH regulation has controlled the phthalates DEHP, DBP, BBP and DIBP in PVC plastic since 2015. REACH regulates the phthalates by requiring a permit to use them for the manufacture of products within the EU. The changed material composition leads to the newly manufactured PVC plastic being separated from the older plastics that were produced within the law change in 2015. The goal of striving for a more circular economy by recycling more PVC plastic interferes with the goal of creating a toxic-free environment, since the older PVC plastic contains the now regulated substances. The purpose of the study is to investigate how this goal conflict affects the recycling of PVC plastic in the construction sector.  A qualitative method has been used for the study and six interviews have been conducted with people from the Innovation and Chemical Industries in Sweden (IKEM), Tarkett, Byggföretagen, Bolon, Naturvårdsverket, IVL Swedish Environmental Institute and BASTA.  The result of the study is that none of the interviewed is of the opinion that the PVC plastic must be replaced or banned. Although they do believe that the policy and scientific evidence that exists must be discussed more, while requirements for eco-labeled PVC plastic must be required to be able to establish a more sustainable management. In order to increase the circular economy, one proposal is to implement logbooks where construction companies can account for the material used during the construction phase, which would then increase traceability and thus the possibilities for recycling.

Mestrado em Gestão e Estratégia Industrial
Em 2019, a Secretaria Geral do Ambiente, Operadora do Programa "Ambiente, Alterações Climáticas e Economia de Baixo Carbono" em Portugal, lançou o concurso "Sistema de reembolso de depósito para garrafas de bebidas e latas", financiando projetos nestas áreas. O objetivo deste trabalho é discutir se os Sistemas de Depósito e Reembolso (SDR) são os instrumentos mais custo-eficientes para fazer a transição de um sistema económico linear, para um sistema circular. Para alcançar este objetivo, esclareceram-se os conceitos de Economia Circular (EC) e de SDR para, depois, os aplicar na análise da circularidade dos projetos. Para o esclarecimento conceptual, fez-se uma revisão da literatura com dois objetivos: enquadrar historicamente o conceito de EC e definir os SDR enquanto instrumentos económicos de mercado simultaneamente custo-eficientes e respeitadores dos princípios da circularidade. Concluiu-se que a literatura aconselha a definição de EC proposta pela fundação Ellen MacArthur e que os SDR são instrumentos custo-eficientes para fechar o ciclo dos fluxos de materiais. Fez-se a análise qualitativa dos projetos de SDR propostos a concurso para avaliar o seu grau de circularidade. Concluiu-se que: aquilo que hoje se designa EC terá as suas raízes nos modelos de fluxos de materiais; que o conceito de EC ainda não está estabilizado; que os SDR são instrumentos de política ambiental mais custo-eficientes para fechar o ciclo de materiais; que, no curto prazo, os indicadores definidos no âmbito do concurso não serão todos cumpridos; e, por último, que nem todos os projetos vão ao encontro dos princípios da Economia Circular.
info:eu-repo/semantics/publishedVersion

Background: Circular economy has received an increasing amount of attention and a move towards a circular economy recently became a top priority within the EU. The food industry contributes to a large amount of the anthropogenic greenhouse gas emissions. In spite of this few studies have explored circular economy in regard to grocery store companies. The lack of prior research in the area serves as a motivation to carry out this study.  Purpose: The purpose of this study is to describe and analyze how grocery store companies have developed their communication to influence their customers’ behaviors and influence the relationship they have with them. Research question: How has the communication regarding a circular economy developed within grocery store companies during 2014-2020? Method: A content analysis of Swedish grocery store companies’ annual reports and sustainability reports between the years 2014-2020 has been conducted. Qualitative coding was mainly used, but some quantitative elements occur. The coding emanated from the two themes plastic and food waste. Results and conclusion: This study shows that the grocery store companies’ circular communication have congregated as a result of changes in the social expectations. The companies have concretized the idea of a circular economy and have introduced their own initiatives to reach it.
Bakgrund: Cirkulär ekonomi är ett begrepp som blivit alltmer uppmärksammat. En övergång till cirkulär ekonomi är numera en av EU:s främsta prioriteringar. Matindustrin bidrar till en stor del av de antropogena utsläppen av växthusgaser. Trots detta finns det få studier som kopplar samman ämnena cirkulär ekonomi och dagligvaruhandel. Bristen på tidigare forskning motiverade att denna studie genomfördes. Syfte: Syftet med studien är att beskriva och analysera hur företag inom dagligvaruhandeln har utvecklat sin kommunikation om cirkulär ekonomi för att påverka sina kunders beteende och relationen de har med dem.  Frågeställning: Hur har kommunikationen kring cirkulär ekonomi utformats inom dagligvaruhandeln mellan åren 2014–2020? Metod: I denna undersökning har en innehållsanalys av aktörerna i den svenska dagligvaruhandelns års- och hållbarhetsrapporter mellan åren 2014–2020 genomförts. Främst användes kvalitativ kodning, men vissa kvantitativa inslag förekommer. Kodningen utgick ifrån begreppen plast och matavfall. Resultat och slutsats: Resultatet av denna studie visar att företagen inom dagligvaruhandeln utformat och ökat sin cirkulära kommunikation på liknande sätt som en följd av förändringar i samhällets förväntningar. Företagen har konkretiserat begreppet cirkulär ekonomi och presenterat egna initiativ för att uppnå det.

Chemical recycling can improve the plastic recycling rates and reduce the level of CO2 from fossil plasticsproduction. Thus, it is seen as an attractive technology in the action towards meeting the emission, circulareconomy and recycling targets. In the Swedish context, it could help reach the carbon neutrality goal by2045. This thesis aims to investigate the potential of chemical recycling in the Swedish plastic recyclingsystem with Brista waste-to-energy plant in Stockholm as a case study. The thesis describes different stagesof current Swedish plastic recycling system and quantifies material losses at every stage. The recycling rateof plastic packaging in the household waste stream in Stockholm was found to be lower than 7%.Remaining 93% is sent for energy recovery through incineration. The feasibility of implementing differentchemical recycling technologies is analysed together with the Technology Readiness Level (TRL). Theresults showed that there are three technologies with the highest TRL of 9: thermal cracking (pyrolysis),catalytic cracking and conventional gasification. The important parameters when implementing chemicalrecycling in an existing facility are discussed and used for the feasibility analysis of implementing thesethree technologies in Brista facility. It is not obvious which technology is the best one for this application.Gasification is proven for the production of intermediates (oil or syngas) which can be used for newplastic production, however, the scale of Brista facility is not large enough for a gasification plant to befeasible. Pyrolysis and catalytic cracking could be used at a smaller scale, but they have not contributed tothe production of new plastics so far, thus, both technologies would require further research and tests ona pilot scale before moving to commercial operation. The findings from this study have to be followed byan in-depth analysis of real data, from pilot or commercial projects, which is currently unavailable.The major challenges to implement chemical recycling of waste plastics in Sweden are of economic andpolitical nature. The key point in successful deployment of chemical recycling is the development ofa business model which would ensure that all actors along the plastic recycling chain benefit economicallyfrom the solution. For the Brista 2 plant case, the challenges include Stockholm Exergi’s insufficientexpertise to perform chemical recycling independently, uncertain feedstock purity requirements andchallenging market situation.
Kemisk återvinning har potentialen att öka återvinningsgraden av plastförpackningar och minska därmedminska klimatpåverkan från fossila plastprodukter. Således ses den som en möjlig teknik för att mötautsläpps- och återvinningsmål samt införandet av en cirkulär ekonomi. I ett svenskt sammanhang kan detbidra till att nå målet om netto noll utsläpp 2045. Denna uppsats syftar till att undersöka potentialen förkemisk återvinning i det svenska återvinningssystemet för plast, med det avfallseldade Bristaverket somfallstudie. Avhandlingen beskriver ingående led i den nuvarande svenska plaståtervinningssystem ochkvantifierar materialförluster i alla steg. Återvinningsgraden för plastförpackningar i hushållsavfalleti Stockholm visar sig vara lägre än 7%. Återstående 93% skickas för energiåtervinning genom förbränning.Analysen av olika teknologier för kemisk återvinnings genomförs med hjälp av Technology ReadinessLevel (TRL). Resultatet visar att det fanns tre teknologier med högsta TRL på 9: termisk krackning(pyrolys), katalytisk krackning och konventionell förgasning. Viktiga parametrar för kemisk återvinningkopplat till en befintlig anläggning diskuteras och används för genomförbarhetsanalys av de tre valdateknologierna genom en fallstudie vid Bristaanläggningen. Det är inte uppenbart vilken teknik som är denbästa för denna applikation. Förgasning är bevisat framgångsrik för produktion av intermediära produkter(olja eller syngas) som kan användas för ny plastproduktion, men Bristaanläggningens storlek är för litenför att en förgasningsanläggning ska varamotiverad. Pyrolys och katalytisk krackning kan användasi mindre applikationer, men de har hittills inte lyckats bidra till framställning av ny plast. Därför skullebåda teknikerna kräva ytterligare forskning och test på pilotskala innan de skalas upp till kommersiell drift.Resultaten från denna studie måste följas av en djupgående analys av verklig data, från pilotprojekt ellerkommersiella projekt, som för närvarande inte är tillgänglig.De stora utmaningarna för att genomföra kemisk återvinning av plastavfall i Sverige är av ekonomisk ochpolitisk karaktär. Nyckeln till framgångsrik spridning av kemisk återvinning är utvecklingen av enaffärsmodell som säkerställer att alla aktörer längs plaståtervinningskedjan kan dra ekonomiskt fördel avlösningen. För en anläggning i Brista finns utmaningar i form av Stockholm Exergis otillräckliga expertisinom området kemisk återvinning, osäkra råvarukrav och en utmanande marknadssituation.

Current design thinking focuses on incremental improvements to a linear system in which products are designed, produced and eventually disposed of. This continued consumption has resulted in over 1 million tonnes of discarded clothing and textiles entering into landfill each year in the UK. The effect of this high volume of waste is not only the loss of embodied energy and value, as re-useable items are disposed of, but continued environmental degradation through greenhouse gas emissions, toxic pollution and rapidly declining landfill space. Whilst consumers are increasingly aware of the consequences of continued consumption, there are limited options to act more responsibly. As much as 70% of textile waste is sent to landfill or incineration from municipal waste collections. In order to investigate these problems it was necessary to consider points at each stage in the cycle using an exploratory sequential mixed methods approach combining case studies, semi-structured interviews and a consumer survey. The practices of those collecting, sorting and grading post-consumer textiles, and those working within circular economy fashion to maximise the reuse and revaluation of such materials through their design practice, were analysed through semi-structured interviews, structured observation and process mapping. An online survey questionnaire evaluated how current consumer attitudes and behaviours would impact upon a circular economy fashion system, assessing how demographic categories define the way individuals view their own practice as consumers, users and eventual disposers. Results show the post-consumer textile collection industry to be in a state of flux. Organisations seeking to reuse and recycle post-consumer clothing and textiles face challenges in promoting the responsible disposal of these items in order to secure supply. Falling sale prices and uncertain collection volumes mean collectors are constantly struggling to extract as much value as possible through sorting and grading activities. Of the volumes collected for reuse and recycling, profit margins are low, resulting in drop in value of around 93% from new to used. Brands and designers working to create change by offering more conscientious product choices are struggling to connect with mainstream fashion consumers, hindered by a lack of industry acceptance and media coverage. Barriers to scaling up circular economy fashion strategies include a lack of market knowledge relating to consumers and the most effective promotional and retail strategies. Consumer insights show the youngest demographic group to be the most characteristic fashion leaders, but they also show the least regard for conscientious consumption. Regarding disposal, over one quarter of respondents across all demographic categories reported throwing old clothes in the bin, with convenience a major factor in such decisions. Indications from consumers show that those working within the industry, such as the brands, designers, producers and employers are viewed as having the greatest responsibility for making conscientious ethical and environmental choices. These findings present significant evidence to guide the development of an effective fashion communication strategy for a circular economy. The outcome is the proposal of a conceptual framework for transitioning towards a circular economy fashion system. This framework provides a guiding strategy for the successful integration of circular economy fashion practices into the mainstream.

Calls have been voiced to change economic and industrial systems such that they align with sustainable development. One concept, circular economy, has emerged recently as a way to rethink waste and resource management. Within this research circular economy is defined as an umbrella concept that centres on the phenomenon of assessing a collection of resource life-extending strategies. This research explored how practitioners interpret the circular economy concept and how this influenced the enactment of waste and resource management, by use of a tool termed the Circularity Compass that was constructed for this purpose. A qualitative case study approach was followed, where 15 participants were interviewed, covering 23 innovation projects for 19 focal companies. The following seven insights stand out. Participants considered 1) materials and products and in particular parts or modules as playing important roles in establishing what resource life-extending strategies are possible; 2) other flows besides those directly related to the manufacturing of a product, such as material flows co-used with the product as well as energy and information flows, and frequently directed their attention at the infrastructure that facilitates these flows; 3) those strategies that allow for the flexible use of product capacity as valid interpretations of what constitutes a resource life-extending strategy; 4) resource life-extending strategies in sets of two or more, where they were frequently thought of as intimately related to each other; 5) addressing one or more barriers seen as inhibiting appropriate waste and resource management directly, whilst other barriers were subject to assumptions not further explored, or not acted upon in a number of cases; 6) various resource life-extending strategies as possibilities of a proposed intervention, without the need to completely resolve targeted routes; and, lastly, 7) participants experienced difficulties progressing the proposed solutions due to an inability to generate financial and political support.

This study is about finding methods for reusing of packaging from Elekta's product "Leksell Gamma Knife ICON" with Circular Economy as the focus. There is no process for this today. The important thing is the analysis of the entire supply chain from Suppliers to customer and then back to Suppliers to get general ideas about what the problems are and then to draw conclusions for the opportunities that exists. The methods used are analyzes if it is cost-effective and environmentally efficient to transport back packaging to the Suppliers who handle these packaging. Costs for the return process have been calculated, which is Supplier work, packaging costs, packaging costs and transport costs. Transport emission in the form of carbon dioxide equivalents have been calculated in the return process. Carbon dioxide equivalents have been calculated for the manufacturing of new packaging and transport by road and ship. The calculated values in the return process are compared with how Elekta is doing today during the process of packing LGK as well as delivering to customers to identify if it is effective to implement a new return process. A solution proposal that fulfils the requirements from an environmental and economic perspective is reported. Environmentally, it is reduced by 459 CO2eq number of carbon dioxide equivalents with transport from the US, 457 CO2eq from China and 1185 CO2eq from Europe. Financially, the company saves 17 190 SEK with transport from the USA, 19327 SEK from China and 18 126 SEK from Europe.
Denna studie handlar att om att hitta metoder för återanvändning av emballagen från Elektasprodukt ”Leksell Gamma Knife ICON” med Cirkulär ekonomi som fokus. Det finns ingen process för detta i dagsläget. Den viktiga är analysen av hela försörjningskedjan från leverantör till kund och sedan tillbaka till leverantörer för att få generella uppfattningar om vad problemen befinner sig och där ifrån dra slutsatser för möjligheterna som finns. De metoder som används är analyser om det är kostnads- och miljöeffektivt att transportera tillbaka emballage till de leverantörer som hanterar dessa emballage. Kostnader för returprocessen har beräknats vilket är leverantörsarbete, emballagekostnader, arbetskostnader och transportkostnader. Transportutsläpp i form av koldioxidekvivalenter har beräknats i returprocessen. Koldioxidekvivalenter har beräknats för tillverkning av nya emballage samt transport med lastbil och fartyg. De beräknade värden i returprocessen jämförs med hur Elekta gör idag under processen att packa LGK samt leverera till kund för att identifiera om det är effektivt att implementera en ny returprocess. Ett lösningsförslag där kraven uppfylls ur ett miljömässigt och ekonomisk perspektiv redovisas. Miljömässigt minskas det med 459 CO2eq antal koldioxidekvivalenter med transport från USA, 457 CO2eq från Kina och 1185 CO2eq från Europa. Ekonomiskt sparar företaget på 17 190 SEK med transport från USA, 19327 SEK från Kina och 18 126 SEK från Europa.

In this I PhD explored the application of the circular economy theory to buildings. I employed methods based on systematic review and meta-analysis, life cycle assessment, case study method and method development. I proposed a method to calculate the circularity of a building. Further, I conceptualized the circular economy building Legacy Living Lab. It resulted that by applying the circular economy to buildings 88% of CO2 emissions can be saved. I produced 5 academic papers.

SMEs are an integral part of the Kenyan economy, and SMEs working with a circular economy (CE)can play a crucial role in contributing to sustainable growth and the nation’s sustainable development goals, Vision 2030. However, these SMEs face several challenges. This study aims to contribute to the body of research on CE and SMEs in developing countries, an area that is under-researched. Through the study, the researchers explore and bring to the fore the barriers and enablers experienced by SMEs practising CE in emerging economies. This study further examines whether SMEs can apply organisational learning to overcome and harness the barriers and enablers. This research is a qualitative study of an exploratory nature. Primary data was collected from SMEs across different sectors through semi-structured interviews. The main findings indicate that the SMEs face barriers with resources, collaborations, infrastructure, regulations and policies, culture, awareness, and the internal and external environment. However, these categories were also found to act as enablers in addition to adaptive spaces and knowledge management. The research further establishes that the present conditions in the external environment attached to weak policies and regulations are a barrier to progression and learning in CE. This study invites further research of circular economy in developing countries and practical solutions for a way forward.

As volumes of packaging waste are increasing worldwide, the urge to reduce environmental and health impacts caused by this waste stream is leading to rising concern over how it is managed and disposed of. At the same time, resource scarcity and linear consumption patterns have regained attention among business leaders, policy makers and people who have become increasingly aware of the importance of reversing this trend using a sustainable model of growth, also known as ‘sustainable development’. The circular economy is a new paradigm within sustainability that focusses on resource efficiency, waste minimisation and low-carbon economy supporting the shift towards sustainable growth and enabling new business opportunities. Using a set of complementary analytical methods, this research evaluates the performance of the Italian system, making use of intervention theory combined with an analysis of the barriers to the circular economy within three areas: regulatory framework, recycling awareness, eco-innovation and prevention. It also describes the functions of CONAI and the results achieved with respect to national and European objectives. In addition, this paper approaches some of the barriers to the circular economy in Italian packaging and packaging waste systems through a case study on a fictitious company selling aluminium coffee capsules whose features are in the context of real world companies dealing with packaging. The findings of this thesis highlight the areas in which Italian packaging and packaging waste management is facing barriers to the circular economy. The findings also highlight how circular economy in Italy is either failing or succeeding, and the potential initiatives and strategies which could overcome barriers to its successful implementation. Moreover, the findings of the case study reveal ways in which to implement circular economy strategies on a specific packaging value chain in Italy while complying with national regulations.

This PhD documents the design, construction and assessment of a Circular economy building: The Legacy Living Lab. L3 is now an operational Curtin University - off campus - building located in Fremantle and it leading the field in circular economy in construction by incorporating 28 industry partners to merge industry academia and society. The results of this PhD include a circular economy index and seven peer reviewed publications.

This thesis argues the need for a fundamental shift from the design of products to the design of possessions in the circular economy. Possessions in the circular economy are characterised by interactions resulting in a user-object relationship rather than legalese and differ from the linear economy in terms of their length of use and number of users. Individual users are thus seen as critical actors to enable material circulation in that they take possession and dispossess of products. Two key topics—psychological ownership and contaminated interaction—are explored in detail to fill theoretical gaps in design research and practice. After discussing these topics, some directions and guidelines are suggested. Possession or ownership is taken as an innate human desire. A framework describes the method of developing ownership including the motives, routes, and paths that guide the development of that relationship. This framework is used to describe object attachment to inform product longevity and decisions around keeping and discarding. It is also useful to help explain why some access-based models are adopted while others are not. Maintaining perceived value in the circular economy entails mitigating contaminated interaction—tainted interaction due to prior use and prior users. Contaminated interaction is shown to affect new circular business opportunities, disposal decisions and downcycling. A typology is presented to characterise indicators of use with an emphasis on sensorial material properties. Aversion to used products is found to come from three drivers: hygiene, utility and territory. A theoretical framework for contaminated interaction is presented which is explored through positive and negative forms of contamination. Finally, a case study shows how alterations in product characteristics lead to improper disposal and act as an example of what it means to design of circular possessions.

This thesis is about Circular Economy and sustainability through a retailer’s perspective. There has also been a focus on researching and trying to find out if the size of the retailer matters in a sustainability perspective and to achieve a Circular Economy. The research that has been made is done with a deductive approach and a qualitative method. Interviews have been held over a timeframe of a week in May 2020. Because of the pandemic, Covid-19, all of the interviews were held over telephone or email to ensure safety for all respondents, including the safety for the authors. The theory chapter has been conducted through peer-reviewed articles and literature. This chapter has then been divided into smaller parts chapters, as Circular Economy, Sustainability and Supply chain, and Triple bottom line. After the theory chapter the method in how the research have been done and why specific methods have been preferred over others. Following chapter is the empirical findings bundled together with analysis, each interview comes first separately and divided in the same way as the theory and are then compared in an analysis. The conclusion is that retailers need to continue working to become more sustainable. A way for retailers to present their work towards Circular Economy and sustainability is to be transparent and will reach consumers’ which can lead to higher reliability. There is a difference between larger and smaller retailers, it is in how the larger retailers have worked more towards incorporate Circular Economy model and sustainability in comparison to the smaller retailers.

This dissertation focuses on the roles of government intervention in developing circular economy. We start with a pre-study of the theories and literature related to circular economy in the developed countries around world. Several case studies are adopted to illustrate the different measures in developing circular economy. Case studies concerning the environmental taxation, the tradable permits and the green certificate system put an emphasis on the economic role of government intervention. A case study of a circular economy in the city of Kristianstad including C4 Energy Company and waste management covers all the measures in harmonization. At last a framework of government interventions and eight proposals based on Swedish experience are tested and supported. Then a comparison between Sweden and China is carried on under a Chinese context through a case study of Chinese Eco-park. The framework is categorized into three aspects: state regulation, economic instruments and social balance mechanism. After the comparison, some modifications are done. We develop a framework and eight proposals in developing a circular economy in China.

Coal fly ash (CFA) can be regarded as a unique material with the potential to be a showcase waste to illustrate the concept of the circular economy. The application of a processing scheme to power station CFA allows the exploitation of multiple components of the product. The CFA can be separated into low density, carbon, and magnetic concentrates as well as the residual fly ashes. This work contributes to a growing body of research that suggests multi component utilisation of CFA is technologically, environmentally, and economically imperative. The thesis explores five separate but related themes that attempt to increase the exploitation of CFA. In the first it is shown that CFA products that are derived from a commercial scale processing scheme exhibit differences in bulk chemistry, mineralogy, and particle size. In the second theme, a study of the rheology of CFA suspensions was conducted. The third aspect of the thesis explores the current method of recovering cenospheres from bulk CFA. The fourth part of the thesis covers the separation of carbon from CFA using an environmentally benign waste material such as vegetable oil. Finally, a silver activated titanium dioxide floating photocatalyst has been manufactured using cenospheres as an industrially derived substrate.

Background: The Circular Economy model came as an alternative to the linear “use and dispose” production system. It argues to promote an economic order that can address the waste of aftermarket goods and a more efficient use of resources and raw materials. It further promises economic gains from a more efficient resource management and extended use of products lifecycle, in conjunction with new employment opportunities that arise as a result of new business models and industrial processes. Whilst the Circular Economy is surely a departure from traditional economic systems, there has been not enough debate on the full impacts as well as possible unintended consequences of its implementation.    Purpose: The purpose is to examine the Circular Economy adoption approach in the Jönköping county in Sweden and how this approach contributes to sustainability improvement.  Purpose: The purpose is to examine the Circular Economy adoption approach in the Jönköping county in Sweden and how this approach contributes to sustainability improvement.  Method: This is an exploratory research which is based on a qualitative design with an inductive approach and interpretive paradigm. The research follows a case study of a pilot project to help SMEs in Jönköping county - Sweden, to implement Circular Economy. The primary data is collected through semi-structured interviews with the project coordinators.  Conclusion: The Circular Economy Project in Jönköping takes into consideration all three resource loops on their implementation of CE based on Bocken et al (2016) resource loops. Embedding all three loops in the implementation of CE is a comprehensive and advanced form of circularity. Combined with the project high-level of sustainability awareness and their effort to integrate the social aspect into their Circular Economy, this research has placed the sustainability profile of the Project at the third level of the corporate sustainability stages presented by Landrum (2018), which is systemic sustainability.

The U.N. projects the world population to reach nearly 10 billion people by 2050, which will cause demand for manufactured goods to reach unforeseen levels. In order for us to produce the goods to support an equitable future, the methods in which we manufacture those goods must radically change. The emerging Circular Economy (CE) concept for production systems has promised to drastically increase economic/business value by significantly reducing the world’s resource consumption and negative environmental impacts. However, CE is inherently limited because of its emphasis on recycling and reuse of materials. CE does not address the holistic changes needed across all of the fundamental elements of manufacturing: products, processes, and systems. Therefore, a paradigm shift is required for moving from sustainment to sustainability to “produce more with less” through smart, innovative and transformative convergent manufacturing approaches rooted in redesigning next generation manufacturing infrastructure. This PhD research proposes the Helical Economy (HE) concept as a novel extension to CE. The proposed HE concepts shift the CE’s status quo paradigm away from post-use recovery for recycling and reuse and towards redesigning manufacturing infrastructure at product, process, and system levels, while leveraging IoT-enabled data infrastructures and an upskilled workforce. This research starts with the conceptual overview and a framework for implementing HE in the discrete product manufacturing domain by establishing the future state vision of the Helical Economy Manufacturing Method (HEMM). The work then analyzes two components of the framework in detail: designing next-generation products and next-generation IoT-enabled data infrastructures. The major research problems that need to be solved in these subcomponents are identified in order to make near-term progress towards the HEMM. The work then proceeds with the development and discussion of initial methods for addressing these challenges. Each method is demonstrated using an illustrative industry example. Collectively, this initial work establishes the foundational body of knowledge for the HE and the HEMM, provides implementation methods at the product and IoT-enabled data infrastructure levels, and it shows a great potential for HE’s ability to create and maximize sustainable value, optimize resource consumption, and ensure continued technological progress with significant economic growth and innovation. This research work then presents an outlook on the future work needed, as well as calls for industry to support the continued refinement and development of the HEMM through relevant prototype development and subsequent applications.

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Circular economy is an economic system aimed at minimizing wastes and making the most of the current resources. This regenerative approach contrasts with the traditional linear economy, which has been adopted by the construction industry. Developing new construction technologies for sustainable built environment is a top priority for the construction industry throughout the world. Much of the environmental impact from the construction industry is associated with the consumption of resources and generation of waste. The construction industry in Europe consumes over 70,000 million tonnes of materials each year and generates over 250 million tonnes of waste. Composite flooring formed by connecting the concrete slabs to the supporting steel beams has been widely used for many years and is well established as one of the most efficient floor systems in multi storey steel frame building structures. However, shear connectors are welded through the steel decking to the steel beams and cast into the concrete; this made deconstruction and reuse of these components almost impossible. A new composite flooring system which allows for the reuse of the steel beams and composite floor slabs is developed and tested to assess its potential and suitability for reuse. This paper presents the results of a series of full scale beam tests and demonstrates the reusability of this new form of composite flooring systems. Simplified hand calculations are also provided and compared against beam tests
EPSRC, Structural Metal Deck Ltd.

This paper explores how policy makers want a transition towards circular economy to look like and what solutions they visualize, with a focus on the why(?) arguments. By analyzing the discourse in states official roadmaps towards circular economy, this study forms an understanding for what motivates a transition. The findings show that the possibilities for economic gains and the creation of new markets are the main purpose to change. In addition to that, whenever the survivability of humanity and the environment was arguments for a change, it in almost all cases came back to the economical outsets with such transition, how much money can be gained/saved.

At present, construction is one of the most destructive, energy consuming and material wasting industries. The current linear system cannot last, and to change anything, we need to redesign the system and our way of thinking. In my thesis, I will explain the theory behind a circular economy and how it could be applied to building, as well as discuss waste issues and material sources. Deconstruction is also a big polluter, and one solution to combat that problem would be to design buildings to be readily disassembled. The aim of this project is to bring awareness about the subject of sustainable design in a modern context and gather this information into one place. Many ideas presented are ones that have been around for as long as people have built buildings, such as material scarcity, resource efficiency and reusing existing materials while reducing waste. Some ecobuilding projects that have successfully implemented these ideas will be presented. In the conclusion, I will present certain concrete ideas and methods for bringing about circular thinking into the built environment. A good starting point would be to decide whether a building needs to be demolished, if so, can the elements be reused or recycled, or if designing a new build with renewable raw materials is the best option
Yhteiskunnassamme rakennusalla kulutetaan nykyään eniten energiaa ja haaskataan materiaaleja. Lineaarinen talous ei kestä nykyistä toimintatapaamme ja muutoksia saamme aikaan vain muuttamalla järjestelmää ja ajattelutapojamme. Diplomityössäni käsittelen kiertotalouden teoriaa ja sen hyödyntämistä rakentamisessa, sekä pohdin jäteongelmia sekä materiaalilähteitä. Myös purkutyö on rakentamisessa suuri saastuttaja ja siihen esitän ratkaisuksi rakennusten suunnittelemista purettaviksi. Diplomityöni tavoitteena on lisästä tietoisuutta kestävän suunnittelun aiheesta (nykyhetken viitekehyksessä) ja koota nämä tiedot yhteen. Monissa esittämistäni konsepteissa hyödynnetään olemassa olevia ideoita, kuten materiaalien saatavuutta ja uudelleenkäyttöä sekä jätteenhallintaa, mutta oleellista on kuinka kokonaisvaltaisesti niitä käytämme. Esimerkkiprojektien avulla havainnollistan konseptien sovellutuksia käytännössä. Lopuksi ehdotan käytännön esimerkein miten kestäviä suunnitteluideoita voi käyttää rakennetussa ympäristössä. Rakentamisessa hyvänä lähtökohtana voi pitää, että rakennusten tulisi olla purettavia, kierrätettäviä ja että uusissa rakennuksissa käytettäisiin uusiutuvia raaka-aineita

The fashion industry has for several years been driven by fast cycles of cheap industrial mass production and unsustainable consumption. At the same time the burden on the environment has been significant. New business models to prevent the environmental impact have therefore been developed, and circular business models have gained interest. Remanufacturing as one of the central activities within circular business model is not a new concept for the fashion and apparel industry, but there is a lack of focus of how to prioritise and develop the concept. The focus of the study is to understand the relative importance of the challenges and the enabling conditions that influence the adoption of remanufacturing as transition towards a circular economy within the fashion and apparel industry. The purpose is also to show the practitioners’ perspective on a relatively new phenomenon within the fashion and apparel industry, which can clarify how to further prioritise and direct the development of the concept. Furthermore, it is also expected to identify and investigate what might be the main challenges and the enabling conditions within remanufacturing. This research is conducted through a mixed method with a deductive approach where knowledge about generic challenges and the enabling conditions within remanufacturing was collected from a systematic literature review, as a modification of a Delphi method. An utilisation of online questionnaires led to verify relative importance of challenges and the enabling conditions for an adoption of remanufacturing as a transition towards a circular economy within the fashion and apparel industry. The result from the online questionnaire was analysed through finding consensus among the collected data. The result shows that the most important perspective for an adoption of remanufacturing was related to business model-, costs- and consumer perspective. Specifically, the challenge with how to change the business model seemed to be essential, and the lack of financial benefits and influencing the consumer behaviour was received to be of great importance. Identified enablers were collaborations and communication. There was no agreement among the most important challenges and the enabling conditions. However, the operations- and core- perspective where considered important by many. Significant consensus was found between the practitioners and their opinion about what influences an adoption of remanufacturing as a transition towards a circular economy. The practitioners’ verification and opinions of challenges and the enabling conditions can serve as support for managers in an adoption of remanufacturing, and provide guidance regarding what is essential to consider for an transition towards a circular economy. This study highlights and identifies what motivates and makes the adoption of remanufacturing attractive, as a way to transition towards a circular economy, in particular it provides support and guidance regarding how strategies can be developed and where to focus further development.

Over the last couple of decades, sustainability has gained importance in the business world, and a concept that has often been used as a prime example of how to deal with today’s environmental problems is circular economy. Even though the topic is relatively new, there has already been quite some debate about its actual advantages and disadvantages, and while there is as of yet no consensus, the majority argues that the application of circular economy practices will be beneficial for the environment. Which is exactly what this research has attempted to ascertain by looking at 78 firms from a wide range of industries yet all from the Nordic region, since this geographical area has been hailed repeatedly for their sustainability. This was done by performing a hierarchical regression analysis on the data in order to explore a possible relationship between the score of a firm on the benchmark of circular economy practices and its corresponding environmental performance, specifically energy consumption, water usage and greenhouse gas emissions. The hierarchical regression analysis showed a significantly positive relationship between a firm’s score on the benchmark of circular economy practices and its energy consumption, while controlling for firm size, industry, debt ratio,slack resources and country of origin, which was contrary to expectations. No such relationship was found between a firm’s benchmark score and their water usage, the same goes for greenhouse gas emissions. Nevertheless, this research has taken an important step in understanding the relationship between circular economy practices and a firm’s environmental performance, and in doing so has opened up new avenues to explore in terms of future research. While the Nordic region is on the right track, there is still a long road ahead.

Mestrado em Ciências Empresariais
Esta dissertação de mestrado visa contribuir com novos conhecimentos académicos no campo da Economia Circular (EC), através da exploração do conceito de EC, procurando compreender a possível contribuição da EC na criação de um sistema mais sustentável dentro de uma organização: a IKEA. Será a Economia Circular será a solução para uma gestão eficiente e sustentável de uma organização? Qual a sua importância para o desenvolvimento das indústrias e a sustentabilidade ambiental? Foram estas as questões de investigação que o estudo de caso da IKEA veio demonstrar que a sustentabilidade e a economia circular não são destinadas apenas a pequenas e médias empresas. A IKEA demonstra que qualquer empresa é capaz de criar produtos com processos de produção circulares, que representam um impacto reduzido no ambiente e expressa, de forma prática, algumas estratégias que pretendem inspirar outras organizações a realizar a transição para processos de produção e gestão mais sustentáveis, neste caso, mais circulares. Não é possível afirmar que a IKEA possua uma gestão totalmente circular, mas está comprometida em atingir esse objetivo.
This thesis aims to contribute with new academic knowledge within the field of Circular Economy (CE). It is done so by exploring the concept of CE and seeks to understand the possible contribution of CE in the creation of a more sustainable system inside an organization: IKEA. Will the Circular Economy be the solution to an efficient and sustainable management of an organization? How important is it to industry development and environmental sustainability? It was these questions of investigation that the IKEA case study demonstrated that sustainability and the circular economy are not just for small and medium-sized enterprises. IKEA demonstrates that any company is able to create products using circular production processes that have a reduced impact on the environment and portrays practical expression of some strategies that are intended to inspire other organizations to make the transition to more sustainable production and management processes, in this case, more circular. It's not possible to say that IKEA has a totally circular management, but it's committed to achieving this objective.
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This  exploratory research  identifies  how  can  clothing companies  implement  textile recyclingtechnologies that help transition them to a sustainable circular economy business model, given the challenges of eco-innovation diffusion. The study is exploratory in nature, employs a literature review and a case study of Patagonia, the outdoor equipment and clothing company that pioneered the use of recycled fibers in the outdoor clothing industry and continues to have today several initiatives for diverting textile waste away from landfills.To implement textile recycling technologies, the company created the Worn Wear Program, the Common Threads Recycling Program and the possibility to return a worn-out garment to Patagonia’s distribution center by mail or from any store or local authorized dealer of Patagonia’s products. To make the recycling (or repurposing) of worn-out garments work, the company also established a repair department at its distribution center which receives all worn-out clothes sent for recycling or repurposing.

More resources are being defined as critical, which can be attributed to the linear economy of ‘take, make and dispose’. An alternative is to implement the circular economy (CE) which could reduce several negative effects, among other things resource depletion. The aim of this thesis is to identify what current sustainability indicators are lacking to assess a resource with the CE concept. This is done by developing CE core indicators, which then are compared with sustainability indicators. The life cycle of rare earth elements (REE) is used as a case study to validate the CE core indicators. To achieve this literature studies and comparative analysis will be performed. Existing definitions and indicators of CE were studied to compile a complete set of core indicators. These compiled CE core indicators were then compared with adapted United Nation (UN) sustainability indicators. The UN indicators were chosen after analysing several different sustainability indicator system and their compatibility with the resource perspective. The main differences between the UN indicators and CE core indicators is that the UN indicators does not include economic aspects such as market diversity and social aspects such as consumption behaviour. However, the UN indicator system includes transportation and governance that could be beneficial to include into the CE concept. The economic viability to perform the CE analysis and non-existing CE indicators for companies and countries were identified as two barriers that could hinder development and efficient use of a CE indicator system. A way to increase the economic viability is to use already generated data for the CE indicator analysis, though the economical aspect has to be studied further. The non-existing CE indicators for companies and countries are counted as a barrier due to the risk of sub-optimisation of one resource. Additionally, the CE indicator results could be misinterpreted to blame a few for the problems of the resource instead of using the results to improve all parts of the life cycle. Further research is also needed to investigate how, or even if, social aspects such as culture and society could be indicated within a CE indicator system. In conclusion, the UN indicator system could be a good baseline to develop a CE indicator system for a resource though further research is needed.

The government has made a choice to call a halt to climate change and has defined concrete milestones that everyone can use in practical terms, but the practical and knowledge side is still lacking within society. There is still no unambiguous approach for circular economy. Unfortunately, no manual is ready yet to take the steps towards 2050. The best advice to give is to start with awareness: making known to the general public. This step is a first step towards 100% circular economy. The greatest effect of circularity of a product must be realized in the design phase. Aspects such as maintenance, flexibility in use and adaptability, disassembly possibilities and the usability at end of life is determined by the design. The choice of materials what a product consists of is also important here. For this, the researcher sought a solution that supports these two important pillars. Circularity is a complex subject and there is a need to convert this complex language whereby this language becomes more intelligible to the daily users, architects, designers and product developers. Making circularity measurable, on the basis of product information from the supplier, the tool calculates the degree of circularity. The focus of the tool lies in the calculation of the impact of its materials and the amount of waste generated during the entire journey of the product. The results of the tool is named PICI© and can be compared with the certification techniques of today, except this one is circular-proof, while almost all of the certifications has been developed within a linear economy. Today's certificates will have to make room for the circularity certificates of the future. In addition, this study will also provide a direction for a circular methodology that will fully support the transition towards a circular service or product development. This research has the aim to make manufacturers, designers, architects or product developers aware what the impact of their product is, whereby the material-decision-making process will be striving for a fully circular  products and the re-use of the those materials.  This tool can motivate and make this impact of waste more visible. On top of that, this tool has a special focus on urban and architectural lighting, due to the collaboration with Spectrum advice and Design, in the Netherlands. Therefore, a case study is included within this study from Hydro Aluminum who supported this research with real-end data.

The aim of this study is to analyze how the concept of circular economy is viewed and defined within the Swedish public sector. Discourse analysis was applied to the semi-structured interviews conducted with employees who work with circular economy projects at local, regional and national institutions. The research found that circular economy was perceived as a way to face resource limitations through continuous circulation of materials, which could also foster economic growth decoupled from extraction of finite resource. Actors perceived as important for the transition to a circular economy are: public sector, business, researchers and civil society, who are believed to be motivated by the notion that a circular economy will lead to a more sustainable society. Furthermore, it is assumed that different partners will work together towards the common goal of circular economy. In addition, the circular economy concept seems to offer a different rhetorical way of approaching environmental problems. The implications of this study could be used to deepen understandings of how circular economy could be implemented.

When designing a product, many decisions are made that determine the environmental impacts the product will eventually exert on our Planet. Indeed, prioritising a material over others, determining how much of this material will be in the finished product and how all the product-components are linked or blended together, are all choices that influence the sustainability of a design. Therefore, it is important to consider the environmental performance already in the design phase. In this thesis, I will showcase the application of the recently developed Resource Pressure (RP) method (Desing et al., 2021) to assess the environmental sustainability of different carpet designs and circular strategies. This method consists of both qualitative guidelines and a quantitative indicator, evaluating the product system concerning the consumption of primary resources and generation of final waste with the Earth's carrying capacity as reference. By following the design guidelines provided by the method, several scenarios are developed with the aim of identifying the most promising changes in design and circular strategies for improving the environmental performance of the product. To evaluate the RP method, the results are compared to a simplified LCA study for twelve of the carpet design scenarios. Comparing RP method to LCA results, a close correlation was observed for most of the impact categories considered. This confirms that the RP method can effectively predict environmental impacts across a wide range of impact categories, without the need for detailed process data and specific LCA knowledge. It can therefore support designers to easily consider the environmental effects themselves and throughout the design process. Moreover, the simplicity of this method makes it attractive to use for a wider group of practitioners.

This thesis reports on research undertaken to investigate the implementation of a Circular approach within the leather industry, through the definition of a framework and development of an economic decision-making support tool. The core objective of the research is to identify the underpinning opportunities and challenges involved in creating recycling solutions for leather waste. The research contributions can be considered in four key areas. The first part of the thesis consists of a review of the use of leather across industry sectors and the existing waste management and recycling systems for leather waste. On consideration of this review it clearly shows a lack of systematic thinking around the creation and optimisation of recovery systems for leather waste. This review concludes that there is significant room for improvement of the current waste management and recycling solutions for leather waste. A variety of value-added products can be recovered from these wastes but only if the leather can be successfully separated from the other materials (such as rubbers and polymers) within end-of-life products and manufacturing wastes. The second part of the research defines a framework for implementing a Circular approach within the leather industry. This framework supports mapping and characterisation of the leather waste stream and the design of recycling and processing strategies for leather waste. The third part of the research is concerned with the development of a decision-support tool for the economic viability of leather recycling systems. The support tool considers all cost factors and combines them to give a single factor upon which the economic effectiveness of different leather recycling scenarios can be evaluated. Finally, the validity of the framework for leather waste recycling is assessed through the completion of two case studies. These case studies demonstrate the flexibility of the framework in supporting both horizontal (across lifecycle) leather recycling and vertical (across industry sector) leather recycling. In summary, the research clearly highlights the need for systematic thinking and flexible strategies when creating leather recycling systems. Failure to incorporate flexibility into future recycling systems puts the recycling industries at risk of being unable to effectively manage future waste streams. Conversely, early consideration and incorporation of flexible processing strategies into recycling systems could enable the recovery of high-quality recycled materials that support a circular approach to manufacturing and resource use.

Most people are aware of the environmental issues that planet Earth is facing, such as climate change, biodiversity loss, water scarcity, expanding deserts and rising sea level. A report from CDP (2017) shows that 100 companies stand for over 70% of the industrial greenhouse gases in the world. The purpose of the study is therefore to facilitate the innovation process of building a sustainable business and addresses the potentials with it. The target group of the study is startups in Sweden developing physical products. Startups were chosen so that already from the beginning of a business, they could be able to build it sustainable. The innovation process explored in the study is the Lean Startup, as it is the most used innovation process by startups (Bortolini et al., 2018). Circular economy is a concept that optimizes the use of resources, eliminates waste and preserves nature. It has been recognized to have big innovation potentials and opens for new business opportunities. In the circular economy, innovation is co-created with all involved stakeholders related to the business, not the least the customers. Earlier research has developed tools, methods and strategies for circular economy that can be used to develop circular projects. With this in consideration, the author addresses the following research questions. • Have startups in Sweden used the Lean Startup process to develop their businesses? • Have startups in Sweden considered circular economy strategies when creating, capturing and delivering value? • Which circular economy tools, methods and strategies can be integrated into the Lean Startup process for startups to develop environmentally friendly businesses? • How would the Lean Startup process with integrated circular economy tools, methods and strategies look like? The study was an exploratory study that gathered data from the literature review on circular economy and the Lean Startup, and from qualitative interviews with startups and experts in different areas within circular economy. The study resulted in a new framework called the Lean Circular Framework, adapted from the Lean Startup process, but with integrated tools, methods and strategies from the circular economy.
De flesta människor är idag medvetna om miljöproblemen som planeten Jorden står inför, så som klimatförändringar, vattenbrist, expanderande öknar och stigande havsnivåer. CDP (2017) visar att 100 företag står för över 70% av alla industriella växthusgaser i världen. Syftet med studien är därför att underlätta innovationsprocessen till att utveckla hållbara affärer och adressera potentialen för dessa. Målgruppen är företag i uppstart i Sverige som utvecklar fysiska produkter. Företag i uppstart blev den valda målgruppen så att man redan från starten av ett företag ska kunna bygga upp hållbara affärer. Innovationsprocessen som undersöktes i studien var Lean Startup eftersom det är den mest använda processen för företag i uppstart (Bortolini et al., 2018). Cirkulär ekonomi är en metodik som optimerar användandet av resurser, eliminerar spill och avfall och bevarar naturen. Den har blivit känd för att ha stor innovationspotential och öppnar upp för nya affärsmöjligheter. I cirkulär ekonomi är innovation skapat tillsammans med alla intressenter inblandade, inte minst kunderna själva. Tidigare forskning har utvecklat verktyg, metoder och strategier för cirkulär ekonomi som kan användas till att utveckla cirkulära projekt. Med detta i åtanke så har författaren svarat på följande forskningsfrågor. • Har företag i uppstart i Sverige använt sig av Lean Startup processen för att utveckla deras företag? • Har företag i uppstart i Sverige övervägt strategier för cirkulär ekonomi när de skapat, fångat och levererat värde? • Vilka verktyg, metoder och strategier från cirkulär ekonomi kan integreras i Lean Startup processen för företag i uppstart för att utveckla miljövänliga företag? • Hur skulle Lean Startup processen med integrerade verktyg, metoder och strategier från cirkulär ekonomi se ut? Studien var en utforskande studie som samlade data från tidigare litteratur om cirkulär ekonomi och Lean Startup, samt från kvalitativa intervjuer med företag i uppstart och experter inom olika områden för cirkulär ekonomi. Studien resulterade i ett nytt ramverk som kallades Lean Circular Framework, anpassad från Lean Startup men med integrerade verktyg, metoder och strategier från cirkulär ekonomi.

Tato práce prezentuje metodologii snižování emisních stop v souvislosti s přechodem na obhovou ekonomiku aplikováním integrace procesů při analýze a projektování při zohlednní výzev, které ztěžují praktické aplikace. Udržitelnost životního prostředí se vyznačuje snahou o snižování emisí a zlepšení hospodaření s odpady a hraje rozhodující roli při přechodu na obhovou ekonomiku. Byly navrženy tři metodiky založené na bezztrátovém konceptu a rozšiřujících metodiky Pinch Analysis a P-Grafů. Aplikovatelnost je demonstrována šesti případovými studiemi transportu a nakládání s odpady. Mé příspěvky v této oblasti jsou následující: (i) Nový bezztrátový rozhodovací nástroj paralelní s klasickým fázovým diagramem, který napomáhá rychlému rozhodování o procesech (např. výběr druhu dopravy pro danou vzdálenost a náklad) při nejnižší možné environmentální zátěži. (ii) Systém kvantitativního vyhodnocování emisí, který agreguje a vyhodnocuje celkové environmentální zatížení způsobené sklemíkovými plyny, SOx, PM a NO2. (iii) Rozšířená analýza nakládání s odpady pro regionální plánování s přihlédnutím k zatěžování i odstranní zatěžování emisní stopou, dále rozhodování o způsobu hospodaření s odpady a výběru způsobu zpracování odpadu s cílem nejnižší možné emisní stopy. (iv) Model posuzování pomocí nástroje P-grafu pro identifikaci optimálních integrovaných systémů zpracování odpadu různého složení, který identifikuje a vyhodnocuje stav udržitelnosti procesů před a po zpracování. Navrhované metodiky v grafickém znázornění s podporou sady komplexních základních rovnic transformují problematiku nakládání s odpady a výběru dopravy do snadno srozumitelné formy řešení vyznačujících se nízkými emisními stopami. Jako příklad v jedné z případových studií analýza provedená podle nového přístupu využívajícího E-WAMPA naznačuje, že celkového snížení emisí o 10% (2, 568 kt CO2 ekv.) Lze dosáhnout provedením přechodu odpadu na Maltě (-25.75 kt CO2 ekv.), Řecko (-1,602.71 kt CO2ekv), Kypr (-178.52 kt CO2ekv) a Rumunsko (-761.16 kt CO2ekv). To jsou země, v nichž lze dosáhnout co největšího zlepšení, vzhledem k kombinovanému účinku čistých emisí (zatěžujících i nezatížených stop) stávajícího systému nakládání s odpady, vzniku odpadů a obyvatelstva. Následující studie budou umožňovat komplexní vyhodnocení ekonomické proveditelnosti tak, aby lokální data mohla být použita pro konkrétní případy v již předpřipravených schématech s výstupem kvalifikovaného řešení.

Circular economy has emerged as a new economic paradigm to solve problems of natural resource scarcity and environmental pollution by using resources more efficiently and designing products to minimize waste. This study examines the potential of circular economy to enable the achievement of sustainable development and the Sustainable Development Goals in Europe. This thesis, through a qualitative content analysis of four overarching European reports related to circular economy strategies, uses a social-ecological systems perspective to: (a) analyze how the three aspects of sustainable development are addressed in the reports and (b) pointing out at missing elements in the European circular economy project that could hinder the realization of the Sustainable Development Goals. Circular economy is a good start to change habits in terms of recycling, reusing and repairing but it also raises awareness about the link between our level of consumption and production and its impact on the environment. However, the results of this study show that the link between Sustainable Development Goals and circular economy is weak and that the economic aspects are highlighted in all the reports to the detriment of environmental and social aspects. As a consequence, the current application of circular economy in Europe does not provide systemic and structural changes, fails to address the root of the problem and reflects a weak vision of sustainability.

Moving towards a more circular economic model is necessary in order to secure the sufficiency of vital raw materials and to achieve a balance between both economic and environmental prosperity. However, the discussion regarding circular economy from a business perspective is still rather limited, and the practical applications of circular economy are mostly related to waste management and industrial applications. Needless to say, circular economy is much more than just large-scale recycling. Circular economy, as a system which aims to ensure a more circular flow of resources, materials and energy, can embody a variety of expressions from closing resource loops to redesigning products, services and the nature of ownership towards favoring renting, sharing, reusing and other alternative ways of maximize the resource efficiency and extend product life. Hence, the principles of circularity can be applied across all industries, instead of just those operating in the industrial sector. Standing on the way of the development of a global circular economy is the perceived mismatched objectives of profit seeking businesses and sustainability advocators. Businesses want high sales levels and profit margins, whereas at the core of environmental sustainability is often to promote conscious consumption and cut down on activities resulting in pollution and waste. And because circular economy is often strongly associated with sustainability matters, businesses tend to stray away from it as it is considered to work against a company’s purpose of making profit. Yet here is the catch – instead of seeing circular economy just as a sustainability tool, it can also be considered as a viable business opportunity which when effectively exploited, can be a source of competitive advantage and a source of economic value

To this day, literature has mainly been focused on the implementation of Circular Economy in the business sector, but as more and more nations adopt the approach of Circular Economy there is a need to further research the role of public agencies in this transition. The City of Malmö is seen as a progressive actor in the field of climate issues and has integrated sustainability objectives widely across the entire organizational culture. However, behaviors and understandings of sustainability are not only connected to organizational culture, but also to organizational subculture. To successfully implement sustainable and circular practices in a public agency there is therefore a need to understand organizational subculture. To initiate the transition towards a circular economy, the municipality of Malmö procured a contract in 2019 that gave the departments of the city an opportunity to purchase circular furniture instead of new. On this foundation, the purpose of this paper was to qualitatively explore what possible subcultures that exist in the City of Malmö and how subcultures can influence circular purchasing practices within a public agency. Empirical data was gathered from semi-structured interviews, individual Organizational Culture Assessment Instrument surveys and strategic documents from five of Malmö’s departments. By analyzing the collected data from the theoretical lens of organizational culture, subculture and Competing Values Framework, this study reached three major findings. Firstly, the study indicates the existence of several organizational subcultures within the City of Malmö, that in various ways influence circular purchasing practices within the municipality. Secondly, circular purchasing is not only affected by subcultural values but also individual values and understandings of sustainability. Finally, multiple barriers and motivators for purchasing circular furniture were identified, where the main barrier shows a cultural and physical distance between the umbrella organization of the municipality and the departments. 2.12.0.0

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Extrudate swell is an important phenomenon in polymer extrusion, affecting many polymer processes. The ability of predicting swell, using rheological properties of the resin, would help the design and operation of plastics processing equipment. Different techniques for predicting swell are reviewed.
A computer program has been written to predict steady-state, isothermal extrudate swell in annular and circular dies. The equations of motion and continuity have been solved along with selected constitutive relations. Newtonian, power-law and the viscoelastic Maxwell and Giesekus rheological models were chosen. The Galerkin formulation of the Finite Element Method has been used to solve the system of differential equations.
The predictions for Newtonian, power-law and Maxwell models have been verified with existing experimental or numerical results when available. The results for the swell of Maxwell and Giesekus fluids have been compared at the same levels of elasticity. The effects of inertia and gravity on extrudate position and swell have been studied. Different geometries of an annular die (converging, diverging) were also examined.

El subministrament d’aliments a les zones urbanes en creixement segueix una tendència lineal: les ciutats consumeixen una gran quantitat d’aliments importats alhora que generen residus i impactes ambientals en diferents fronts. L’agricultura urbana (UA) ha destacat com una pràctica per mitigar la quantitat d’aliments importats, generant beneficis en les tres dimensions de la sostenibilitat i una excel·lent oportunitat per a la restauració de fluxos. El concepte d’economia circular (CE) pot contribuir a aquesta mitigació minimitzant els fluxos de residus i aprofitant estratègies per recuperar recursos mentre s’exploten les sinergies entre sistemes urbans, contribuint a la millora del metabolisme urbà. No obstant això, l’aplicació dels principis de la CE als sistemes de la UA s’ha de controlar estrictament en termes de comportament ambiental per evitar un xoc entre els objectius de la CE i la sostenibilitat. Per evitar-ho, la present tesi pretén avaluar el comportament ambiental de l’aplicació d’estratègies circulars en sistemes de UA. Per arribar a aquest objectiu, utilitzem l’anàlisi de cicle de vida (ACV) combinada amb altres mètodes i eines complementàries: estudi dels fluxos de nutrients, anàlisi de variables climàtiques, sistemes d’informació geogràfica o avaluació de la circularitat mitjançant l’indicador de circularitat de materials (MCI). En primera instància analitzem el rendiment ambiental de 25 cicles de 7 cultius diferents en un hivernacle hidropònic en coberta per determinar quins haurien de ser els elements de l’inventari a optimitzar i definir les millors combinacions anuals de cultius. Els resultats mostren que els fertilitzants i les seves emissions a l’aigua són l’element amb més marge de millora. En aquest sentit, avaluem l’aplicació de tres possibles estratègies de recuperació de nutrients: filtració per membranes, precipitació química i recirculació directa de lixiviats, trobant que aquesta última és la que presenta el millor comportament ambiental. Tenint en compte això, avaluem mitjançant diferents enfocaments el rendiment de dues estratègies de recirculació diferents: la recirculació de lixiviats en un mateix cultiu i la recirculació de lixiviats en un cultiu paral·lel en el que es coneix com a sistema en cascada. Els resultats de l’anàlisi descriuen els potencials i les limitacions d’ambdós sistemes, concloent que la configuració definitiva inclouria un sistema en cascada en què el cultiu receptor reutilitzi els nutrients que lixivia. El fòsfor (P) és un recurs escàs i valuós a causa de la demanda antropogènica per produir fertilitzants. La sinergia entre sistemes urbans pot contribuir a augmentar la utilitat dels recursos de P a nivell urbà. En aquest sentit, analitzem la recuperació d’estruvita a les plantes de tractament d’aigües residuals urbanes i la seva aplicació en sistemes UA amb dos enfocaments diferents: (1) experimentalment per comprovar el seu potencial i limitacions en sistemes hidropònics, i (2) amb una perspectiva regional que tracta una àrea metropolitana com una entitat auto-suficient. Els resultats mostren com l’ús d’estruvita pot generar produccions més elevades que els fertilitzants minerals, a més de disminuir les pèrdues de P. La perspectiva regional a la recuperació i reutilització d’estruvita mostra com l’àrea estudiada és capaç de recuperar prou P per alimentar tota l’agricultura de la regió, tot i que alguns paràmetres com l’elecció de la planta de tractament d’aigües residuals o la tecnologia de recuperació implementada són importants per evitar impactes ambientals addicionals. Tenint en compte les conclusions de la tesi, es poden definir diferents línies de recerca futures: estandardització de mètriques i conceptes al voltant de l’economia circular o integració de diferents perspectives en l’avaluació de sistemes UA.
El suministro de alimentos en zonas urbanas en crecimiento sigue una tendencia lineal: las ciudades consumen una gran cantidad de alimentos importados, generando residuos e impactos ambientales en distintos frentes. La agricultura urbana (UA) ha permitido disminuir la cantidad de alimentos importados, generando beneficios en las tres dimensiones de la sostenibilidad y una excelente oportunidad para la restauración de flujos. El concepto de economía circular (CE) puede contribuir a esta mitigación minimizando los flujos de residuos y aprovechando estrategias para recuperar recursos mientras se explotan las sinergias entre sistemas urbanos, contribuyendo a la mejora del metabolismo urbano. Sin embargo, la aplicación de los principios de la CE a los sistemas de la UA se debe controlar estrictamente en términos de comportamiento ambiental para evitar un choque entre los objetivos de la CE y la sostenibilidad. Para evitar esto, la presente tesis pretende evaluar el comportamiento ambiental de la aplicación de estrategias circulares en sistemas de UA. Para llegar a este objetivo, utilizamos el análisis de ciclo de vida (ACV) combinado con otros métodos y herramientas complementarias: estudio de los flujos de nutrientes, análisis de variables climáticas, sistemas de información geográfica o evaluación de la circularidad mediante el indicador de circularidad de materiales (MCI). En primera instancia analizamos el rendimiento ambiental de 25 ciclos de 7 cultivos diferentes en un invernadero hidropónico en cubierta para determinar cuáles deberían ser los elementos del inventario a optimizar y definir las mejores combinaciones anuales de cultivos. Los resultados muestran que los fertilizantes y sus emisiones al agua son el elemento con más margen de mejora. En este sentido, evaluamos la aplicación de tres posibles estrategias de recuperación de nutrientes: filtración por membranas, precipitación química y recirculación directa de lixiviados, concluyendo que esta última es la que presenta el mejor comportamiento ambiental. Teniendo en cuenta esto, evaluamos mediante distintos enfoques el rendimiento de dos estrategias de recirculación diferentes: la recirculación de lixiviados en un mismo cultivo y la recirculación de lixiviados en un cultivo paralelo en lo que se conoce como un sistema en cascada. Los resultados del análisis describen los potenciales y las limitaciones de ambos sistemas, concluyendo que la configuración definitiva incluiría un sistema en cascada en el que el cultivo receptor reutilice los nutrientes que lixivia. El fósforo (P) es un recurso escaso y valioso debido a la demanda antropogénica de P para producir fertilizantes. La sinergia entre sistemas urbanos puede contribuir a aumentar la utilidad de los recursos de P a nivel urbano. En este sentido, analizamos la recuperación de estruvita en las plantas de tratamiento de aguas residuales urbanas y su aplicación en sistemas UA con dos enfoques diferentes: (1) experimentalmente para cuantificar su potencial y limitaciones en sistemas hidropónicos, y (2) con una perspectiva regional que trata un área metropolitana como una entidad auto-suficiente. Los resultados muestran como el uso de estruvita puede generar producciones más elevadas que los fertilizantes minerales, además de disminuir las pérdidas de P. La perspectiva regional en la recuperación y reutilización de estruvita muestra como el área estudiada es capaz de recuperar suficiente P para alimentar toda la agricultura de la región, aunque algunos parámetros como la elección de la planta de tratamiento de aguas residuales o la tecnología de recuperación implementada son importantes para evitar impactos ambientales adicionales. Teniendo en cuenta las conclusiones de la tesis, se pueden definir diferentes líneas de investigación futuras: estandarización de métricas y conceptos alrededor de la economía circular o integración de diferentes perspectivas en la evaluación de sistemas UA.
Food supply to ever-growing urban areas follows a linear tendency: cities consume a vast amount of imported food while generating waste and environmental impacts in different fronts. Urban agriculture (UA) has stood out as a practice to mitigate the volume of the imported flow, generating benefits in all three dimensions of sustainability and an excellent opportunity for the restoration of flows. The young concept of a circular economy (CE) can contribute to this mitigation by minimizing waste flows and take advantage of strategies to recover resources while exploiting synergies between urban systems, contributing to an improvement of the urban metabolism. However, the application of CE principles in UA systems should be strictly monitored in terms of environmental performance to avoid a clash between CE and sustainability goals. To avoid this, the present thesis aims to evaluate the environmental performance of applying circular strategies in UA systems. We use the Life Cycle Assessment (LCA) combined with other complementary methods and tools: nutrient balances, analysis of climatic variables, geographical information systems or a circularity assessment through the material circularity indicator (MCI). We first analyze the environmental performance of 25 cycles of 7 different crops in a hydroponic rooftop greenhouse to determine which should be the targets to optimize within the inventory and define the best year-round crop combinations. The results show that the fertilizers and their related emissions to water are the item with the biggest room for improvement. To avoid nutrient depletion, we evaluate the application of three possible nutrient recovery strategies: membrane filtration, chemical precipitation and direct leachate recirculation, finding that the latter had the best environmental performance. Considering this, we evaluate with different approaches the performance of two different recirculation strategies: the recirculation of leachates in the same crop and the recirculation of leachates in a parallel crop in what is known as a cascade system. The results of the analysis outline the potentials and limitations of both systems, concluding that the ultimate configuration would include a cascade system in which the receiving crop reuses the nutrients that leaches. Phosphorus (P) is a scarce and valuable resource due to the anthropogenic demand to produce fertilizers. The synergy between urban systems can contribute to enlarge the utility of P resources at the urban level. In this sense, we analyze the recovery of struvite in urban wastewater treatment plants and its application in UA systems with two different approaches: experimentally to test its potential and limitations in hydroponic systems, and with a regional perspective that treats a metropolitan area like a self-sufficient entity. The results show how the use of struvite can produce higher yields than mineral fertilizers while diminishing P losses. The regional perspective showed how the area under study is able to recover enough P to feed all the agriculture of the region, although parameters like the choice of the wastewater treatment plant or the recovery technology are important to avoid additional environmental impacts. Finally, we gather all the recovery strategies and evaluate their environmental performance and degree of circularity to prioritize circular strategies in UA systems. After solving detected limitations of the assessment through indicator development, we find that nutrient recirculation, the use of struvite or recycled materials are the best strategies to improve both the circularity and environmental performance of the system. Considering the findings of the thesis, different future research lines were defined: standardization of circular economy metrics and concepts or integration of different perspectives in the assessment of UA systems.

Current human activities have a significant impact on the socio-ecological system, endangering this system’s capacity to support human civilization and biodiversity. Today’s linear industrial model can be seen as a main driver of this challenge, which implies a need for a model that uses less raw material and is more aligned with the cyclical nature of Earth. A concept that claims to provide such a model is Circular Economy (CE). This study analyses CE for its potential contribution to strategic sustainable development, and explores the barriers and enablers companies face in its implementation process. The main methodologies used for this research include the analysis of the concept by means of a conceptual framework and a Framework for Strategic Sustainable Development, as well as interviews with experts in related fields. The research exposed several gaps between CE and strategic sustainable development. The main barriers were found on a technological, legal, economic level, and at the behavioural level, i.e. the difficulty to change mindsets. Leadership, collaboration, the CE concept itself and customer behaviour were identified as important enablers. These results show that the concept is difficult to implement and that there is a need for a refined approach, which is easier to apply while leading closer towards sustainability.

Inspired by the way nature cycles waste in an ecosystem, the circular economy was developed as an alternative to the linear take-make-dispose model and designed to decouple economic growth from resource use. After developing a framework for what it means to be a business pursuing circularity, this thesis examines six different companies to explore the tension between the strategies and business models in theory and what business are implementing in practice today. This exploration continues with an in-depth analysis of the circular success of IKEA, finding that the gains from the circular economy for a large corporation are found within their own operations. With the company’s scale, IKEA is able to act as a transfer hub of technology and best practices, ultimately allowing the company to make a global impact.