Industrial symbiosis networks are generally assumed to provide economic and environmental benefits for all firms involved, though few quantifications have been produced in the literature, and the methods for these quantifications have varied. This paper provides an approach to quantify the environmental performance of industrial symbiosis networks using guidance from the literature of life cycle assessment. Additionally, an approach to distribute credits due to exchanges for firms in the industrial symbiosis network is outlined. From the approach, influential methodological considerations used for the quantifications are discussed, including e.g. the production of reference systems, allocation methods, system boundaries and functional unit. The implications of such an approach may be beneficial for the industrial symbiosis community and provide information crucial for taxes, subsidies, business relations, expansion possibilities for the network, marketing and other issues related to the environmental performance of firms in the industrial symbiosis network.

As the production of biofuels continues to expand worldwide, criticism about, e.g. the energy output versus input and the competition with food has been questioned. However, biofuels have the possibility to be optimized in order to improve the environmental performance. This could be accomplished through the use of concepts from industrial symbiosis. This paper provides a quantification of the environmental performance of industrial symbiosis in the biofuel industry through integration of biogas and ethanol processes using a life cycle approach. Results show that although increasing integration is assumed to produce environmental benefits, not all impact categories have achieved this and the results depend upon the allocation methods, energy system and assumptions chosen.

The production of biofuels has increased in recent years, to reduce the dependence on fossil fuels and mitigate climate change. However, current production practices are heavily criticized on their environmental sustainability. Life cycle assessments have therefore been used in policies and academic studies to assess the systems; with divergent results. In the coming years however, biofuel production practices must improve to meet strict environmental sustainability policies.

The aims of the research presented in this thesis, are to explore and analyze concepts from industrial symbiosis (IS) to improve the efficiency and environmental performance of biofuel production and identify possible material and energy exchanges between biofuel producers and external industries.

An exploration of potential material and energy exchanges resulted in a diverse set of possible exchanges. Many exchanges were identified between biofuel producers to make use of each other’s by-products. There is also large potential for exchanges with external industries, e.g. with the food, energy and chemical producing industries. As such, the biofuel industry and external industries have possibilities for potential collaboration and environmental performance improvements, though implementation of the exchanges may be influenced by many conditions.

In order to analyze if concepts from IS can provide benefits to firms of an IS network, an approach was created which outlines how quantifications of IS networks can be produced using life cycle assessment literature for guidelines and methodological considerations. The approach offers methods for quantifying the environmental performance for firms of the IS network and an approach to distribute impacts and credits for the exchanges between firm, to test the assumed benefits for the firms of the IS network.

Life cycle assessment, and the approach from this thesis, have been used to quantify the environmental performance of IS networks by building scenarios based on an example from an IS network of biofuel producers in Sweden. From the analyses, it has been found that exchanges of material and energy may offer environmental performance improvements for the IS network and for firms of the network. However, the results are dependent upon the methodological considerations of the assessments, including the reference system, functional unit and allocation methods, in addition to important processes such as the agricultural inputs for the system and energy systems employed.

By using industrial symbiosis concepts, biofuel producers have possibilities to improve the environmental performance. This is done by making use of by-products and waste and diversifying their products, promoting a transition toward biorefinery systems and a bio-based economy for regional environmental sustainability.

Produktionen av biobränslen har ökat de senaste åren, vilket är ett steg mot klimateffektivare lösningar i transportsektorn, men biodrivmedlen har ifrågasatts med hänvisning till tveksamheter kring deras miljö- och energiprestanda. Lifecykelanalyser har därför använts inom akademiska studier och för policy för att utvärdera systemen, dock utan samstämmiga resultat. Under de kommande åren måste därför praxis för produktion av biobränslen förbättras för att kunna möta de strikta kraven i hållbarhetskriterier för biobränslen.

Syftet med forskningen som presenteras i den här doktorsavhandlingen är att utforska och analysera koncept från området Industriell symbios (IS) och därigenom identifiera förbättringar för ökad effektivitet och miljöprestanda för biobränsleproduktion. Vidare är syftet att identifiera möjliga material- och energiutbyten mellan biobränsleproducenter och externa industrier.

Potentiella material- och energiutbyten undersöktes, vilket resulterade förslag på flera olika typer av potentiella utbyten. Undersökningen visar på en potential för att använda biprodukter i en biobränsleprocess som råvara till en annan biobränsleframställning. Vidare identifierades en stor potential för utbyten med externa industrier, som till exempel matproducenter samt industrier för energi och kemikalier. Det är tydligt att det finns möjligheter för biobränsleproducenter och externa industrier att samarbeta och därmed ge möjlighet till förbättringar i miljöprestandan, dock kan en implementering av dessa utbyten påverkas av många olika förutsättningar.

Avhandlingen presenterar även ett tillvägagångssätt för att visa hur kvantifiering av miljöprestanda inom ett nätverk för IS kan genomföras genom att använda riktlinjer och metodavvägningar från litteratur för livscykelanalys.  Detta tillvägagångssätt kan användas för att analysera om koncept från IS kan leda till fördelar för företagen i ett IS-nätverk.

Tillvägsgångssättet ger möjlighet att kvantifiera miljöprestandan för företagen i IS-nätverket och ger dessutom vägledning för hur miljöpåverkan från utbytena kan distribueras mellan de olika företagen. Metoden utvecklades för att bland annat undersöka de förmodade fördelarna från IS för varje enskild aktör.

Livscykelanalys i kombination med tillvägagångssättet ovan har använts för att kvantifiera miljöprestandan för IS-nätverk genom att konstruera scenarier. Scenarierna har baserats på ett exempel från ett IS-nätverk av biobränsleprocenter i Sverige. Analyserna visar att utbyten av material- och energi kan ge förbättringar i miljöprestanda. Resultaten är dock beroende av vilka metodavvägningar som gjorts, till exempel val av referenssystem, funktionell enhet och allokeringsmetoder. Vidare spelar viktiga processer som inputs från jordbruk och val av energisystem stor roll för resultatet.

Metodavvägningar för utväderingen influerar även miljöpåverkan samt hur den fördelas mellan företagen i IS-nätverket. Dessutom kan den lokala miljöpåverkan öka medan den globala påverkan minskar.

Sammanfattningsvis kan biobränsleproducenter, genom att använda koncept från industriell symbios, ges möjlighet att förbättra sin miljöprestanda. Detta kan ske genom att använda biprodukter och avfall samt genom att diversifiera sina produkter som ett första steg mot en övergång mot bioraffinaderier och en mer biobaserad ekonomi för regional hållbarhet.

Background: With criticism about the economic viability and environmental performance of biofuels, theuse of byproducts and integration with external industries could be achieved to improve their performanceand provide further use for byproducts and wastes. Methodology: A review of potential byproduct andutility exchanges between biofuel and external industries has been documented in this article through aliterature review and brainstorming workshop, and results have been classified based on their interactions.Results: It has been found that byproduct exchanges, especially those between biofuel industries, andexchanges between the biofuel industries and the food, feed, agriculture and energy industries, offer manypotential exchanges. Conclusion: The identified synergies offer possibilities for potential collaborationpartners in symbiotic exchanges with the biofuel industry.

The massive consumption of finite resources creates high economical and environmental costs due to material dispersion and waste generation. In order to overcome this, by-products and wastes may be used, to avoid the use of virgin materials and benefit from the useful inherent energy of the material. By adding value to the material, economic and environmental performance can be improve, which is called upcycling. In this paper, an exergy and economic analysis of a biogas process is examined. In order to investigate if biogas production from wastes can upcycle materials, biogas production from a by-product from the brewing process is examined. From the analysis, the process is found to upcycle the by-product with an increase in exergy and economic benefit due to the generation of biomethane and biofertilizer. This analysis thus shows that by using by-products as such, the sustainability of the system may improve.

It is generally assumed that industrial symbiosis creates economic and environmental benefits for all firmsinvolved, though only a few quantifications have been produced in the literature. An approach to quantifyenvironmental performance of industrial symbiosis using life cycle assessment has been provided,outlining the choice of functional unit, system boundaries, impact assessment and allocation as well as thedistribution of benefits among firms in the symbiotic activity. The implications of such an approach maybe beneficial for the industrial symbiosis and life cycle assessment communities and provide informationcrucial for taxes, subsidies, business relations, marketing and other issues related to the environmentalperformance of firms in the industrial symbiosis network.

As the production of biofuels continues to expand worldwide, criticism about many issues, including the energy output versus input and the competition with food, has been raised andthe sustainability of biofuels in recent years has been constantly debated. However, the current biofuel systems may be optimized to increase the energy efficiency and environmentalperformance. By using concepts from industrial symbiosis, the material and energy exchangesmay be optimized to result in these performance improvements. This paper offers aquantification of the environmental performance of industrial symbiosis in the biofuelindustry through integration of biogas and ethanol processes using a life cycle approach.Results show that although increasing integration between the biogas and ethanol plants isassumed to produce environmental benefits, not all impact categories have achieved this andthe results depend upon the allocation methods chosen. Thus the increasing integration alsobrings about increased complexity for the system.

Biofuels are being employed in nearly all the EU member states to fulfill the targets set up by the European Directive 2003/30/EC to have a 5.75% share of renewable energy in their transport sector by 2010. In Sweden ethanol is the leading biofuel, while biogas mainly depend on local initiatives with the city of Linköping as a case in point.

Our purpose with this article is to analyze the development of biogas in Linköping within a framework of technological transition theory. To this we add a set of concepts from large technical systems-literature to address and re-analyze two earlier studies on the biogas development in Linköping to achieve a deeper understanding of this success story. We argue that the establishment of a development trajectory for biogas depended on the ability of the involved actors to establish and nurture their social network, to create learning processes and stimulate the articulation of expectations and visions. It was also important that these three factors were allowed to influence each other for the system to gain a momentum of its own.

Furthermore, the biogas development in Linköping is found to be interesting in that the triggers for the development came from a variety of levels and angles. Initially, the rising fuel prices after the oil crises in the 1970’s resulted in an increased interest in renewable fuels in general. Second, an anticipated national pipeline for natural gas planned through Linköping was considered a huge potential for methane exports. A part from these external energy incentives, the local trigger was the bad urban air quality caused by the public transport authority’s bus fleet. The breakthrough came when it was discovered that by-product biogas from the wastewater treatment facility could be used as a fuel for transport.

When the plans for the national pipeline were rejected, a fruitful co-operation between the municipally owned production facility and the public transport authority was set up to meet the constructed demand from public transport. This cooperative pair-arrangement was the starting point for the biogas niche trajectory as other actors subsequently were enrolled to increase the size and agency of the network.

Nowadays, biogas and other renewable fuels play a significant role in the supply of transport fuels for Linköping. In 2009, a total of 9.5% of all transport fuels used in Linköping were from renewable sources, i.e. biogas (4.6%), ethanol and biodiesel. This puts the city well ahead of the European target of 5.75% renewable fuels by 2010.

In the production of biofuels for transport many critics have argued about the poor energyefficiency and environmental performance of the production industries. Optimism is thusset on the production of second generation biofuels, while first generation biofuelscontinue to dominate worldwide. Therefore it is interesting to consider how the environmentalperformance of first generation biofuel industries can be improved. The field ofindustrial symbiosis offers many possibilities for potential improvements in the biofuelindustry and theories from this research field are used in this paper to highlight howenvironmental performance improvements can be accomplished. This comes in the formof by-product synergies and utility synergies which can improve material and energyhandling. Furthermore, the processes and products can gain increased environmentalperformance improvements by the adaption of a renewable energy system which will actas a utility provider for many industries in a symbiotic network. By-products may thereafterbe upcycled through biogas production processes to generate both energy and a biofertilizer. A case study of an actual biofuel industrial symbiosis is also reviewed to providesupport for these theories.