Daily and seasonally fluctuating energy supply and demand requires adequate energy storage solutions. In recent years electrochemical supercapacitors have attracted considerable attention due to their ability to both store and deliver electrical energy efficiently. Our efforts are focused on developing and optimizing sustainable organic electrode materials for supercapacitors based on renewable bioorganic materials, offering a cheap, environmentally friendly and scalable alternative to store energy. In particular, we are using the second most abundant biopolymer in nature, lignin (Lig), which is an insulating material. However, when used in combination with electroactive and conducting polymers such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT), the biohybrid electrodes PPy/Lig and PEDOT/Lig display significantly enhanced energy storage performance as compared to the pristine conducting polymers without the lignin. Redox cyclic voltammetry and galvanostatic charge/discharge measurements indicate that the enhanced performance is due to the additional pseudocapacitance generated by the quinone moieties in lignin. Moreover, a conjugated redoxpolymer poly(aminoanthraquinone) PAAQ, with intrinsic quinone functions and excellentstability, has been combined with lignin and PEDOT resulting in a trihybrid bioelectrode. PEDOT compensates the low conductivity of PAAQ and provides electrical pathways to the quinone groups. The electrochemically generated quinones undergo a two electron, two protonredox process within the biohybrid electrodes as revealed by FTIR spectroelectrochemistry.These remarkable features reveal the exciting potential of a full organic energy storage device with long cycle life. Therefore, supercapacitor devices were designed in symmetric or asymmetric two electrode configuration. The best electrochemical performance was achieved by the asymmetric supercapacitor based on PEDOT+Lignin/PAAQ as the positive electrode and PEDOT/PAAQ as the negative electrode. This device exhibits superior electrochemical performance and outstanding stability after 10000 charge/discharge cycles due to the synergistic effect of the two electrodes. Finally, we have characterized the response of this supercapacitor device when charged with the intermittent power supply from an organic photovoltaic module. We have designed charging/discharging conditions such that reserve power was available in the storage device at all times. This work has resulted in an inexpensive fully organic system witht he dual function of energy conversion and storage.

The aim of this study was to assess the feasibility of moderate thermal treatment (70 ^◦C for one hour) of digestate in combination with post-digestion targeting residual biomethane potentials from three full-scale biogas plants digesting food waste (FW), agricultural waste (AW) and a mixture of AW and manure (AWM). Dissolved organic carbon (DOC), biomethane production, and digestate quality were investigated. For the study six laboratory-scale continuously stirred tank biogas reactors working as post-digesters, with thermally-treated and non-treated digestate were used. DOC for thermally-treated digestates increased significantly (t-test, p < 0.05); FW-digestate (110–200 %), AW-digestate (24–92 %) and for AWM-digestate (4–73 %). Indexes for corresponding DOC quality showed lower apparent organic molecular weights and decreased aromaticity (with the exception of FW-digestate). Thermal treatment of digestate improved the biomethane production during post-digestion by 21–22 % (FW-digestate) and 9 % (AW-digestate). For AMW-digestate no clear positive effect was observed, most likely due to biogas plant operational process disturbances. 

This chapter re ects the design and starting performance of the Symbiotic bio- Energy Port Integration with Cities by 2020 project (EPIC 2020). The EPIC 2020 project is coordinated by the city of Malmö and is performed in four harbour cities: Malmö in Sweden, Mantova in Italy, Navipe-Akarport in Greece, and Wismar (including Rostock) in Germany. A number of expert organisations and energy companies also take part in the project.

The overall objectives of EPIC 2020 are to build operational and strategic capacity and know-how to promote ef cient use of available bioenergy resources, ef cient conversion technologies and interactions between different biomass supply chains. EPIC 2020 targets the untapped bioenergy resource potential of ports and port regions and the challenge of generating urban economic growth based on bioenergy resources. The project applies the industrial symbiosis approach to achieve its overall objectives.

Ports provide crossing points between transport modes of goods and resources, with connections to hinterland and on-site industrial activities and a nearby urban setting. This means that ports, despite their limited areal footprint, have access to signi cant quantities of bio wastes, surrounding bioenergy resources, biomass from crossing supply chains and energy from intensive activities. The aim is to create platforms for the transformation of port areas to ef cient and carbon-neutral urban-integrated energy systems, where residual bio and energy resources and linear biomass supply chains are utilized as local and network resources.

The EPIC 2020 project is halfway the 3-year performance framework. Re ection to primary results is provided. 

This thesis assessed the technical and economic premises for installing systems that process manure in order to recover nutrients and inherent energy. The main purpose of recovering nutrients was to extract phosphorus from the manure, so as to be able to distribute more of the manure on the farm without exceeding the phosphorus regulation. Three other scenarios were included as reference; conventional manure handling, solid-liquid separation only and solid-liquid separation including energy recovery. Since most important parameters for modeling scenarios in agriculture are site-specific (e.g. soil type, crop rotation and manure composition), the thesis results were based on a case farm. The case farm is a 675 ha dairy farm with approx. 1400 milking cows, located in Östergötland, Sweden.

As for the results, it was first concluded that the central characteristics of manure were the content of dry matter (DM), nitrogen (N), phosphorus (P) and potassium (K). The higher the DM content, the more fuel for energy recovery, and the higher the N:P-ratio, the more on-farm N can be utilized before having to consider the P regulation. The technical premises for farm-scale nutrient recovery were limited to commercial techniques from companies operating in Sweden, and included various possible processing methods, such as; pH modification, anaerobic digestion, coagulation-flocculation, precipitation, filtration and reverse osmosis. However, most methods were either too costly or simply not realistic to install on stand-alone farms, resulting in only two feasible options; struvite precipitation and secondary solid-liquid separation with a decanter centrifuge.

The comparison in economic performance for all scenarios resulted as follows: nutrient recovery by struvite precipitation was the most profitable scenario of all, if struvite was allowed to replace mineral P fertilizer (i.e. end-product on-farm utilization). If not, it was more profitable to invest in only energy recovery, as nutrient recovery by secondary solid-liquid separation or struvite precipitation with end-product sales were not as profitable. However, the absolutely largest increase in profitability lies within investing in a primary solid-liquid separation. As for the case farm, this investment reduced costs by more than 2 MSEK, while any of the latter scenarios reduce costs by 0,1-0,2 MSEK. Furthermore, the possible utilization of the waste heat from energy recovery increased profitability by a factor of ten.

This article is focused on performing a SWOT analysis of agricultural waste management methods. This approach can be applied in the biogas technology strategic planning process in Ukraine, which can solve the issue of implementation of environmental guidelines for the development of biofuels and biofertilizers. The main factors that determine how digestate is used are its quality, local conditions, regulations, and documents. Fertilizing fields with digestate provides many advantages, for example: reduced demand for plant protection products, reduction of unpleasant odor, and destruction of possible pathogens. The strengths and weaknesses of the implementation of biogas plants in Ukraine have been identified, and opportunities and threats have been considered. In general, the introduction of biogas technology is a very promising solution for the agricultural sector. Taking into account that a biogas plant is considered a potentially hazardous object for workers, it is necessary to constantly monitor the parameters of reactor operation in order to ensure the technological and environmental safety of the engineering facilities. For Ukraine, there is a shortage of specialists to set up an effective operation of biogas equipment and bring it to the industrial scale. It is necessary to consult with medium and small farms interested in the feasibility study and implementation of biogas technologies. 

Biogas production via anaerobic digestion is an established and robust technology that produces energy and recycles nutrients. Several biotechnological attempts have been applied to this process to increase biogas production, including adding nanoparticles, but several discrepancies have been reported. To elucidate the contradictory results, we performed a literature review followed by a meta-analysis to evaluate the effect of adding natural nanoparticles to biogas sludge. Our results showed that adding nanoparticles can increase biogas production by up to two orders of magnitude. Considering that, we attribute these results to variability in the nanoparticles applied, leading to less reliable, consistent, and even contradictory results. We observed that the magnetite nanoparticles are the most tested ones with the most promising positive effects. In addition, we observed that concentrations of nanoparticles higher than 100 mg/L can have adverse effects, with an overall decrease in biogas production. The findings in this study highlight the need for a proper characterization of the nanomaterials type and concentration applied to the process to understand the interactions and effects on the microbial communities and dynamics that lead to an overall increase or decrease in biogas yield.

The pulp and paper industry is a large producer of wastewater and sludge, putting high pressure on waste treatment. In addition, more rigorous environmental legislation for pollution control and demands to increase the use of renewable energy have put further pressure on the pulp and paper industry’s waste treatment, where anaerobic digestion (AD) and the production of methane could pose a solution. Kraft pulping makes up 80% of the world production of virgin wood pulp, thus, the wastewaters from this sector represent a large unused potential for methane production.

There are three main types of substrates available for AD at pulp and paper mills, the wastewaters, the primary sludge/fibre sludge, and the waste activated sludge. AD treatment of these streams has been associated with several challenges, such as the presence of inhibiting compounds or low degradability during AD. The aim of this thesis was to experimentally address these challenges and potentials, focusing on wastes from kraft mills.

Methane potential batch tests showed that many wastewater streams still posed challenges to AD, but the alkaline elemental chlorine-free bleaching stream and the condensate effluents had good methane potentials. Further, the methane potential of kraft mill fibre sludge was high, and co-digestion of kraft mill fibre sludge and waste activated sludge was feasible in stirred tank reactors with sludge recirculation. By increasing the organic loading in a pilot-scale activated sludge facility and thereby lowering the sludge age, the degradability of the waste activated sludge was improved. The higher wastewater treatment capacity achieved by this method provides an opportunity for the mills to increase their pulp and paper production. Further, by dewatering the digestate after AD and returning the liquid to the activated sludge treatment, costs for nutrient supplementation can be reduced.

In conclusion, the thesis shows that AD of wastes from the kraft pulp and paper industry was feasible and carried many benefits regarding the generation of methane as a renewable energy carrier, improved wastewater treatment and reduced costs. Different strategies on how AD may be implemented in the kraft pulp and paper industry were formulated and discussed.

Kraft fibre sludge from the pulp and paper industry constitutes a new, widely available substrate for thebiogas production industry, with high methane potential. In this study, anaerobic digestion of kraft fibresludge was examined by applying continuously stirred tank reactors (CSTR) with sludge recirculation.Two lab-scale reactors (4L) were run for 800 days, one on fibre sludge (R1), and the other on fibre sludgeand activated sludge (R2). Additions of Mg, K and S stabilized reactor performance. Furthermore, theCa:Mg ratio was important, and a stable process was achieved at a ratio below 16:1. Foaming was abatedby short but frequent mixing. Co-digestion of fibre sludge and activated sludge resulted in more robustconditions, and high-rate operation at stable conditions was achieved at an organic loading rate of 4 gvolatile solids (VS) L1 day1, a hydraulic retention time of 4 days and a methane production of230 ± 10 Nm L per g VS.

Increased viscosity and the presence of extracellular polymeric substances (EPS) and soluble microbial products (SMP) are important factors that may negatively affect wastewater treatment processes, e.g. foaming, inefficient mixing or poor dewatering. Many industries, including the pulp and paper industry, are running their production processes at shifting conditions, leading to large variations in wastewater composition to downstream treatments. The aim of this study was to investigate how changes in organic loading rate (OLR) and hydraulic retention time (HRT) affect the viscosity and production of EPS and SMP during anaerobic digestion of pulp and paper mill sludge. Two lab-scale continuous stirred tank reactors (CSTRs) were operated for 800 days at 37⁰C. The OLR was increased and the HRT was decreased in steps. Reactor fluid was sampled once a month for rheological characterization and analysis of EPS and SMP.

Our results demonstrated a clear positive correlation between viscosity and the production of EPS and SMP. OLR, magnesium and potassium were important for EPS and SMP formation and the protein fraction of SMP was negatively correlated to HRT and sludge retention time. The production of EPS and SMP was important in foam formation and sludge bulking, either directly through their surface-active properties, or indirectly by increasing the viscosity. Sludge bulking was avoided by more frequent mixing. In conclusion, rheological measurements and estimates of EPS and SMP contents could prove valuable tools to avoid the severe consequences of sludge bulking and foaming in full-scale applications.

The growing need for climate mitigation solutions has contributed so thatbiochar has gained significant interest. Primary for its ability as a carbon sinkbut there is also a growing interest due to several other aspects within industriese.g. substitution effects, increased resource efficiency, an enabler forindustrial symbiosis, and its beneficial properties when put in soil that can increasegrowth.

Previous studies of biochar have been dominant within the environmentalperspective of biochar, analyzing detailed characteristics of its propertiesand carbon sink potential. Some studies have a holistic perspective reflectingon countries specific energy mix and the different benefits of producingbiochar. However, previous studies are far too few to determine the value-chainof biochar. Hence previous studies have knowledge gaps within the holistic lifecycle approach from a provider or customer perspective of biochar, not reflectingon demand for quality requirements in different utilization areas and markets.The need for validation of the environmental and the economic performanceof biochar has to be established, and the economic perspective of biochar hasmajor knowledge gaps since previous studies are scarce.

The study aims to establish the value-chain of biochar by evaluating theenvironmental, economic, and social perspectives through life cycle thinking.The core of the study is to distinguish value, which first has to reflect thebiochar quality requirements from providers and customers, captured throughinterviews and literature research. The quality requirements enable a goal forproducing biochar and determine what processes and biomass are needed fordifferent markets. This is evaluated through a case development which considersthe different quality requirements. Life cycle assessment (LCA) with acradle-to-grave perspective and life cycle costing (LCC) with a cradle-to-gatewere then used to distinguish biochar´s environmental and economic performance.

The interviews and researched literature resulted in three cases being developed,biochar application in electric arc furnaces in steel production, agriculturalapplication, and commercial application through biochar-macadam. Thesteel industry has higher quality requirements due to the need to have a similarcomposition as fossil coal, resulting in biochar produced from wood being theonly option. The limitations for agricultural application are more related tothe allowed amount of phosphorus per ha and thus all the researched biocharapplies to different degrees. Biochar application in biochar-macadam is similarto agricultural application, however limited due to the EBC certification notallowing the production of biochar from sludge.

The generated results from the LCA show that the climate performance isvastly different depending on what biomass was utilized and the different markets.Biochar produced from park and garden, and wood results in a higher climateperformance due to the higher carbon sequestration compared to biocharproduced from straw and sludge, however depending on how the biocharis utilized, the performance varies. During biochar application in electric arcfurnaces, the majority of the produced carbon sink is destroyed which resultsin worse climate performance, instead the majority of the reduced emissionscomes from the substituted fossil coal. Compared to biochar application inagricultural and biochar-macadam where the carbon sink stays intact, steel applicationstill has worse climate performance even when including substitution.Biochar-macadam production results in more emissions compared to agriculturalapplication due to the need to mix biochar with stones and compost,thus biochar in agriculture is the best option from a climate perspective. The economic aspects are generated through the conducted LCC which resulted inbiochar produced from park and garden, and sludge being more beneficial dueto the absence of acquisition costs. Production of biochar from wood provesto be difficult when considering a larger time frame, with the market for steelproduction not returning the investment. Biochar produced from straw hasa positive return on investment when considering the agriculture market, butnot for the production of biochar-macadam. The results show that the marketof biochar is very uncertain due to being considered immature and a futuremarket. The major uncertainty is connected with the immaturity of the market.The quality requirements are not reflected in the market pricing which isone of the major reasons for biochar utilization in the steel industry not beingeconomically beneficial.

The value chain of biochar is a combination of many different economic,environmental, and social values. The conducted LCA shows that there areclimate benefits due to carbon sequestration, and a possibility to replace fossilreferences. Other than biochar there are also by-products such as heat and oilwhich can be utilized, improving the climate performance further. The multipleproducts also have economic benefits due to the potential of creating multipleproducts. The carbon sink can be sold as carbon credits, and the heat can beutilized in district heating. For providers, the creation of biochar is an enablerto reduce environmental impact, utilize products already within the system,and create value from waste. The structure of biochar generates a lot of valuefor customers. The porosity enables water storing capabilities which increasesthe efficiency of watering. This reduced the amount needed for soil applications,while also securing the harvest from drought and flooding. Even though thevalue chain of biochar shows that there is a lot of potential, it is still uncertainhow it will be integrated into society, and how the market will be shaped in theyears to come.

In this paper, we performed technology assessment and systems analysis of primary digestate processing techniques to provide a comprehensive analysis of their environmental and cost performance. We compiled more than 100 observations from large-scale biogas plants and considered digestate based on manure, crops and agro-wastes, and food waste under the geographical contexts of Sweden and Belgium. Centrifuge, screw press, and rotary drum were identified as suitable primary processing techniques. We analyzed the climate impact, energy use, and operational cost of digestate management under these scenarios: no processing, partial processing (solid-liquid separation) and full processing (solid-liquid separation followed by ammonia stripping). As expected, the suitable digestate processing varied with the context, transport was often the most critical cost factor, and emissions from storage reduced the climate savings from the use of biofertilizers. However, treating liquid fraction became a main contributor to cost and climate impact under the Belgian conditions. Consequently, the possibility for local application of liquid fraction as biofertilizer could prevent costs and impacts associated with its further treatment. The main novelty of this work is in its integrative and comprehensive approach toward the choices and impacts of primary processing of digestate. We tried to bridge many individual case studies, drew from experiences of biogas plants in different geographical contexts, assessed suitable processing techniques for different digestate types, and analyzed the environmental impacts and cost of digestate management from a life cycle perspective. We believe that such integrated approaches would help decision-making for increased sustainability of the biogas sector. 

Carbon dioxide is released by natural and anthropogenic processes, such as the production and combustion of fossil fuels. Production of biogas also generates carbon dioxide, but of biogenic origin. The global, yearly emissions of greenhouse gases are regularly increasing, although agreements such as the Paris Agreement is signed by parties globally. Sweden has the goal to reach net-zero emissions by 2045, and thereafter to only obtain negative emission levels. To reach these goals the biogenic version of Carbon Capture and Storage (CCS) called Bioenergy with Carbon Capture and Storage (BECCS) is considered to be an essential strategy. Using carbon dioxide, through Carbon Capture and Utilization (CCU), in for example products, can complement BECCS since the strategy can increase the value of carbon dioxide. These strategies make it possible to reduce the climate impact of biogas production. 

This master thesis aimed to chart different techniques in CCS and CCU to examine how they can be used to utilize or store carbon dioxide from biogas plants. What technical demands different solutions create was explored. The different techniques were assessed through a multi criteria analysis by a technological, environmental, marketable and economical standpoint to investigate which ones were the most suitable for a specific, studied case – Tekniska verken’s biogas plant. One suitable technique within CCU was analyzed through a screening of actors in the region. An environmental assessment of one technique in CCS and one in CCU were compared with the reference case Business as usual, to explore how a simulated biogas plant’s climate impact can change through the implementation of CCS and CCU. 

The charting of literature gave findings of 42 different techniques, which were sifted down to 7; algae farming for wastewater treatment, BECCS in saltwater aquifers, carbon dioxide curing of concrete, bulk solutions, production of methanol, production of methane through Power To Gas and crop yield boosting in greenhouses. The multi criteria analysis pointed out carbon dioxide curing of concrete and BECCS in saltwater aquifers as suitable solutions for the studied case. The implementation of these techniques requires a liquefaction plant, infrastructure for transportation as well as business partners. 

A life cycle assessment of the studied cases climate impact was given through modelling and simulation of a model plant of the studied case, with the functional unit 1 Nm3 biomethane. The reference case Business as usual had a climate impact of 0,38 kg CO2 eq, which corresponds to approximately one eighth of the climate impact of fossil fuels such as gasoline or diesel. By storing the carbon dioxide through BECCS in saltwater aquifers the climate impact decreased to - 0,42 kg CO2 eq. By utilizing the carbon dioxide through curing of concrete the biomethane’s climate impact decreased to -0,72 kg CO2 eq. The results thereby evince that Swedish biogas producers can improve their climate performance through CCS and CCU. 

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.

It is generally assumed that industrial symbiosis creates economic and environmental benefits for all firms involved, though few quantifications have been produced. The environmental performance of an industrial symbiosis network will be quantified using an approach from previous literature. Additionally, the benefits provided by exchanges have partitioned to firms taking part in the industrial symbiosis network, which may have implications for tax incentives, marketing, expansion and environmental awareness. The current industrial symbiosis network has been found to have benefits compared to reference scenarios produced. However, methodological choices, such as the choice of reference scenario and allocation methods may significantly influence the results of the environmental performance.

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.

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.

Industrial symbiosis (IS) involves collaborations among diverse, and predominantly local and re- gional, actors that create additional economic and environmental value through by-product ex- changes, utility and service sharing, and joint innovations. While the importance of IS for the de- velopment of biofuels is commonly recognised hypothetically, this study aims at advancing under- standing of the actual contribution provided in two real life examples–one focusing on grain-based ethanol production and the other focusing on biogas production in a co-digestion unit. Moreover, this study highlights the importance of organisational factors that help shape, and explain relevant organizational and inter-organizational behaviour relevant for emergence and development of suc- cessful symbiotic partnerships – here referred to as “social determinants”.

Studied cases provide clear insights on multiple business and environmental benefits of IS. Reduc- ing input and operational costs, increasing material and energy productivity, creatively improving access to substrate with improved social acceptance, reducing exposure to market volatilities, and providing improved environmental performance–with market differentiation advantages–are among key impacts observed. Moreover, IS strategies are also found to enable creation of new mar- kets, assist the evolution towards more complex bio-refineries, and help with recognising biofuel industry as an integral part of sustainable resource use at a wider societal level.

With regards to organisational determinants of synergistic partnerships, the findings of the study reinforce the importance of organisational proximity, alignment of strategic objectives and organi- sational cultures, intensity and quality of communication, inter-organisational knowledge exchange and learning, formulation of effective and efficient governance mechanisms, trust building, and level of support from different public governance bodies. While the organisational proximity pro- vided by common ownership and being part of the same organisational field assists synergy devel- opment in initial phases, as the parties accumulate relevant capabilities, they are able to move to- wards more complex and more rewarding partnerships. The findings also emphasise that with dedi- cated support from governance bodies, particularly at the local and regional levels, development of knowledge-, relational- and mobilisation capacities for IS can be enhanced, and these can catalyse accelerated development of synergistic relations benefiting both the biofuel industry and the wider society. 

This study used semi-continuous laboratory scale biogas reactors to simulate the effects of trace-element addition in different combinations, while degrading the organic fraction of municipal solid waste and slaughterhouse waste. The results show that the combined addition of Fe, Co and Ni was superior to the addition of only Fe, Fe and Co or Fe and Ni. However, the addition of only Fe resulted in a more stable process than the combined addition of Fe and Co, perhaps indicating a too efficient acidogenesis and/or homoacetogenesis in relation to a Ni-deprived methanogenic population. The results were observed in terms of higher biogas production (+9%), biogas production rates (+35%) and reduced VFA concentration for combined addition compared to only Fe and Ni. The higher stability was supported by observations of differences in viscosity, intraday WA-and biogas kinetics as well as by the 16S rRNA gene and 16S rRNA of the methanogens.(c) 2015 Elsevier Ltd. All rights reserved.

Background: In a previous study, single-stage processes were compared with two-stage processes, using either food waste alone or mixed with thin stillage as substrate. Overall methane yield increased (by 12%) in two-stage compared with single-stage digestion when using food waste, but decreased when food waste was co-digested with thin stillage (50:50 on VS basis). The obtained difference in methane yield was likely caused by a higher acetate level in the first stage reactor operating with food waste alone (around 20 g/L) compared to the reactor also treating thin stillage (around 8 g /L). The present study sought to shed additional light on possible causes of the large difference in methane yield by scrutinizing the microbial community in the first- and second-stage reactors, using a combined Illumina sequencing and qPCR approach. Results: In the first-stage process, acid-tolerant Aeriscardovia and Lactobacillus formed a highly efficient consortium. For food waste with high levels of acetate (20 g/L, equal to 0.14 g acetate/g VS) was produced but when thin stillage was added the pH was lower (&lt;4), resulting in lactate production exceeding acetate production. This difference in hydrolysate composition between the reactors resulted in development of slightly different communities in the second-stage, for both hydrolysis, fermentation, and acetogenesis. High acetate concentration appeared to promote proliferation of different syntrophic consortia, such as various syntrophic acetate oxidizers, members of the genus Syntrophomonas and candidate phylum Cloacimonetes, likely explaining the higher methane yields with two-step compared with single-stage digestion of food waste. Conclusion: Using food waste as sole substrate resulted in enrichment of Lactobacillus and Aeriscardovia and high acetate yields in the first-stage reactor. This was beneficial for biogas yield in two-stage digestion, where efficient acid-degrading syntrophic consortia developed. Addition of thin stillage contributed to low pH and higher lactate production, which resulted in decreased methane yield in the two-stage process compared with using food waste as sole substrate.

Acetate production from food waste or sewage sludge was evaluated in four semi-continuous anaerobic digestion processes. To examine the importance of inoculum and substrate for acid production, two different inoculum sources (a wastewater treatment plant (WWTP) and a co-digestion plant treating food and industry waste) and two common substrates (sewage sludge and food waste) were used in process operations. The processes were evaluated with regard to the efficiency of hydrolysis, acidogenesis, acetogenesis, and methanogenesis and the microbial community structure was determined. Feeding sewage sludge led to mixed acid fermentation and low total acid yield, whereas feeding food waste resulted in the production of high acetate and lactate yields. Inoculum from WWTP with sewage sludge substrate resulted in maintained methane production, despite a low hydraulic retention time. For food waste, the process using inoculum from WWTP produced high levels of lactate (30 g/L) and acetate (10 g/L), while the process initiated with inoculum from the co-digestion plant had higher acetate (25 g/L) and lower lactate (15 g/L) levels. The microbial communities developed during acid production consisted of the major genera Lactobacillus (92-100%) with food waste substrate, and Roseburia (44-45%) and Fastidiosipila (16-36%) with sewage sludge substrate. Use of the outgoing material (hydrolysates) in a biogas production system resulted in a non-significant increase in bio-methane production (+5-20%) compared with direct biogas production from food waste and sewage sludge.

This study investigated the possibility to use thermophilic anaerobic high solid digestion of dewatered digested sewage sludge (DDS) at a wastewater treatment plant (WWTP) as a measure to increase total methane yield, achieve pasteurization and reduce risk for methane emissions during storage of the digestate. A pilot-scale plug-flow reactor was used to mimic thermophilic post-treatment of DDS from a WWTP in Linköping, Sweden. Process operation was evaluated with respect to biogas process performance, using both chemical and microbiological parameters. Initially, the process showed disturbance, with low methane yields and high volatile fatty acid (VFA) accumulation. However, after initiation of digestate recirculation performance improved and the specific methane production reached 46 mL CH4/g VS. Plug flow conditions were assessed with lithium chloride and the hydraulic retention time (HRT) was determined to be 19–29 days, sufficient to reach successful pasteurization. Degradation rate of raw protein was high and resulted in ammonia-nitrogen levels of up to 2.0 g/L and a 30% lower protein content in the digestate as compared to DDS. Microbial analysis suggested a shift in the methane producing pathway, with dominance of syntrophic acetate oxidation and the candidate methanogen family WSA2 by the end of the experiment. Energy balance calculations based on annual DDS production of 10 000 ton/year showed that introduction of high-solid digestion as a post-treatment and pasteurization method would result in a positive energy output of 340 MWh/year. Post-digestion of DDS also decreased residual methane potential (RMP) by>96% compared with fresh DDS.

Anaerobic digestion has been widely applied for waste treatment, renewable energy generation , biofertilizer production. The biogas potential in Brazil is sizable, but the state of Rio de Janeiro is largely dependent on fossil fuels , there is a lack of biogas potential assessments in the state. Thus, this study evaluated biomethane, electricity and biofertilizer potentials in the region. Three different scenarios of biomass supply were considered for four major biowaste streams: sewage sludge; cattle manure; sugarcane processing waste; and food waste. Biomethane generation from the assessed sources could reach 0.6-1.3 billion Nm(3) year(-1), corresponding to 1,768-3,961 GWh year(-1) of electricity , 1.6-3.3 million Mg year- 1 of biofertilizer. Cattle manure was responsible for 73-84% of the projected biomethane production, presenting an opportunity to reduce the sig-nificant emissions from livestock farming. The estimated biofertilizer production could meet the demands of the state , the produced electricity could offset up to 10% of the demand. The gas grid could facilitate the dis-tribution of upgraded biomethane, and 10-22% of the natural gas demand could be met. The findings of this work highlight the high potential for biogas generation in Rio de Janeiro, which is up to seven times larger than the current production.

With a high availability of lignocellulosic biomass and various types of cellulosic by-products, as well as a large number of industries, Sweden is a country of great interest for future large scale production of sustainable, next generation biofuels. This is most likely also a necessity as Sweden has the ambition to be independent of fossil fuels in the transport sector by the year 2030 and completely fossil free by 2050. In order to reach competitive biofuel production costs, plants with large production capacities are likely to be required. Feedstock intake capacities in the range of about 1-2 million tonnes per year, corresponding to a biomass feed of 300-600 MW, can be expected, which may lead to major logistical challenges. To enable expansion of biofuel production in such large plants, as well as provide for associated distribution requirements, it is clear that substantial infrastructure planning will be needed. The geographical location of the production plant facilities is therefore of crucial importance and must be strategic to minimise the transports of raw material as well as of final product. Competition for the available feedstock, from for example forest industries and CHP plants (combined heat and power) further complicates the localisation problem. Since the potential for an increased biomass utilisation is limited, high overall resource efficiency is of great importance. Integration of biofuel production processes in existing industries or in district heating systems may be beneficial from several aspects, such as opportunities for efficient heat integration, feedstock and equipment integration, as well as access to existing experience and know-how.

This report describes the development of BeWhere Sweden, a geographically explicit optimisation model for localisation of next generation biofuel production plants in Sweden. The main objective of developing such a model is to be able to assess production plant locations that are robust to varying boundary conditions, in particular regarding energy market prices, policy instruments, investment costs, feedstock competition and integration possibilities with existing energy systems. This report also presents current and future Swedish biomass resources as well as a compilation of three consistent future energy scenarios.

BeWhere is based on Mixed Integer Linear Programming (MILP) and is written in the commercial software GAMS, using CPLEX as a solver. The model minimises the cost of the entire studied system, including costs and revenues for biomass harvest and transportation, production plants, transportation and delivery of biofuels, sales of co-products, and economic policy instruments. The system cost is minimised subject to constraints regarding, for example, biomass supply, biomass demand, import/export of biomass, production plant operation and biofuel demand. The model will thus choose the least costly pathways from one set of feedstock supply points to a specific biofuel production plant and further to a set of biofuel demand points, while meeting the demand for biomass in other sectors.

BeWhere has previously been developed by the International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria and Luleå University of Technology and has been used in several studies on regional and national levels, as well as on the European level. However, none of the previous model versions has included site-specific conditions in existing industries as potential locations for industrially integrated next generation biofuel production. Furthermore, they also usually only consider relatively few different production routes. In this project, bottom-up studies of integrated biofuel production have been introduced into a top-down model and taken to a higher system level, and detailed, site-specific input data of potential locations for integrated biofuel production has been included in the model.

This report covers the first stages of model development of BeWhere Sweden. The integration possibilities have been limited to the forest industry and a few district heating networks, and the feedstocks to biomass originating from the forest. The number of biofuel production technologies has also been limited to three gasification-based concepts producing DME, and two hydrolysis- and fermentation-based concepts producing ethanol. None of the concepts considered is yet commercial on the scale envisioned here.

Preliminary model runs have been performed, with the main purpose to identify factors with large influence on the results, and to detect areas in need of further development and refinement. Those runs have been made using a future technology perspective but with current energy market conditions and biomass supply and demand. In the next stage of model development different roadmap scenarios will be modelled and analysed. Three different roadmap scenarios that describe consistent assessments of the future development concerning population, transport and motor fuel demands, biomass resources, biomass demand in other industry sectors, energy and biomass market prices etc. have been constructed within this project and are presented in this report. As basis for the scenarios the report “Roadmap 2050” by the Swedish Environmental Protection Agency (EPA) has been used, using 2030 as a target year for the scenarios. Roadmap scenario 1 is composed to resemble “Roadmap 2050” Scenario 1. Roadmap scenario 2 represents an alternative development with more protected forest and less available biomass resources, but a larger amount of biofuels in the transport system, partly due to a higher transport demand compared to Roadmap scenario 1. Finally Roadmap scenario 3 represents a more “business as usual” scenario with more restrictive assumptions compared to the other two scenarios.

In total 55 potential biofuel plant sites have been included at this stage of model development. Of this 32 sites are pulp/paper mills, of which 24 have chemical pulp production (kraft process) while eight produce only mechanical pulp and/or paper. Seven of the pulp mills are integrated with a sawmill, and 18 additional stand-alone sawmills are also included, as are five district heating systems. The pulp and paper mills and sawmills are included both as potential biofuel plant sites, as biomass demand sites regarding wood and bioenergy, and as biomass supply sites regarding surplus by-products. District heating systems are considered both regarding bioenergy demand and as potential plant sites.

In the preliminary model runs, biofuel production integrated in chemical pulp mills via black liquor gasification (BLG) was heavily favoured. The resulting total number of required production plants and the total biomass feedstock volumes to reach a certain biofuel share target are considerably lower when BLG is considered. District heating systems did not constitute optimal plant locations with the plant positions and heat revenue levels assumed in this study. With higher heat revenues, solid biomass gasification (BMG) with DME production was shown to be potentially interesting. With BLG considered as a production alternative, however, extremely high heat revenues would be needed to make BMG in district heating systems competitive.

The model allows for definition of biofuel share targets for Sweden overall, or to be fulfilled in each county. With targets set for Sweden overall, plant locations in the northern parts of Sweden were typically favoured, which resulted in saturation of local biofuel markets and no biofuel use in the southern parts. When biofuels needed to be distributed to all parts of Sweden, the model selected a more even distribution of production plants, with plants also in the southern parts. Due to longer total transport distances and non-optimal integration possibilities, the total resulting system cost was higher when all counties must fulfil the biofuel share target. The total annual cost to fulfil a certain biofuel target would also be considerably higher without BLG in the system, as would the total capital requirement. This however presumes that alternative investments would otherwise be undertaken, such as investments in new recovery boilers. Without alternative investments the difference between a system with BLG and a system without BLG would be less pronounced.

In several cases the model located two production plants very close to each other, which would create a high biomass demand on a limited geographic area. The reason is that no restrictions on transport volumes have yet been implemented in the model. Further, existing onsite co-operations between for example sawmills and pulp mills have not always been captured by the input data used for this report, which can cause the consideration of certain locations as two separate plant sites, when in reality they are already integrated. It is also important to point out that some of the mill specific data (obtained from the Swedish Forest Industries Federation’s environmental database) was identified to contain significant errors, which could affect the results related to the plant allocations suggested in this report.

Due to the early model development stage and the exclusion of for example many potential production routes and feedstock types, the model results presented in this report must be considered as highly preliminary. A number of areas in need of supplementing have been identified during the work with this report. Examples are addition of more industries and plant sites (e.g. oil refineries), increasing the number of other production technologies and biofuels (e.g. SNG, biogas, methanol and synthetic diesel), inclusion of gas distribution infrastructures, and explicit consideration of import and export of biomass and biofuel. Agricultural residues and energy crops for biogas production are also considered to be a very important and interesting completion to the model. Furthermore, inclusion of intermediate products such as torrefied biomass, pyrolysis oil and lignin extracted from chemical pulp mills would make it possible to include new production chains that are currently of significant interest for technology developers. As indicated above, the quality of some input data also needs to be improved before any definite conclusions regarding next generation biofuel plant localisations can be drawn.Due to the early model development stage and the exclusion of for example many potential production routes and feedstock types, the model results presented in this report must be considered as highly preliminary. A number of areas in need of supplementing have been identified during the work with this report. Examples are addition of more industries and plant sites (e.g. oil refineries), increasing the number of other production technologies and biofuels (e.g. SNG, biogas, methanol and synthetic diesel), inclusion of gas distribution infrastructures, and explicit consideration of import and export of biomass and biofuel. Agricultural residues and energy crops for biogas production are also considered to be a very important and interesting completion to the model. Furthermore, inclusion of intermediate products such as torrefied biomass, pyrolysis oil and lignin extracted from chemical pulp mills would make it possible to include new production chains that are currently of significant interest for technology developers. As indicated above, the quality of some input data also needs to be improved before any definite conclusions regarding next generation biofuel plant localisations can be drawn.

A further developed BeWhere Sweden model has the potential for being a valuable tool for simulation and analysis of the Swedish energy system, including the industry and transport sectors. The model can for example be used to analyse different biofuel scenarios and estimate cost effective biofuel production plant locations, required investments and costs to meet a certain biofuel demand. Today, concerned ministries and agencies base their analyses primary on results from the models MARKAL and EMEC, but none of these consider the spatial distribution of feedstock, facilities and energy demands. Sweden is a widespread country with long transport distances, and where logistics and localisation of production plants are crucial for the overall efficiency. BeWhere Sweden considers this and may contribute with valuable input that can be used to complement and validate results from MARKAL and EMEC; thus testing the feasibility of these model results. This can be of value for different biofuel production stakeholders as well as for government and policy makers. Further, Sweden is also of considerable interest for future next generation biofuel production from a European perspective. By introducing a link to existing models that operate on a European level, such as BeWhere Europe and the related IIASA model GLOBIOM, BeWhere Sweden could also be used to provide results of value for EU policies and strategies.

The potential of the screen printing method for large-scale production of organic electrochemical transistors (OECTs), combining high production yield with low cost, is here demonstrated. Fully screen-printed OECTs of 1mm(2) area, based on poly(3,4-ethylenedioxythiophene) doped with poly(styrensulfonate) (PEDOT:PSS), have been manufactured on flexible polyethylene terephthalate (PET) substrates. The goal of this project effort has been to explore and develop the printing processing to enable high yield and stable transistor parameters, targeting miniaturized digital OECT circuits for large-scale integration (LSI). Of the 760 OECTs manufactured in one batch on a PET sheet, only two devices were found malfunctioning, thus achieving an overall manufacturing yield of 99.7%. A drain current ON/OFF ratio at least equal to 400 was applied as the strict exclusion principle for the yield, motivated by proper operation in LSI circuits. This consistent performance of low-footprint OECTs allows for the integration of PEDOT:PSS-based OECTs into complex logic circuits operating at high stability and accuracy.

As the anthropogenic greenhouse gas emissions continue imposing stress on our environment, it is becoming increasingly important to identify and implement new renewable technologies. Biogas production through anaerobic digestion has a great potential, since it links waste treatment with extraction of renewable energy, enabling circular bio-economies that are vital for a sustainable future.

For biogas to have an important role as a renewable energy carrier in society, the scale of its production will need to be increased substantially. New substrates need to be introduced along with raising organic loading rates of the reactors to increase the rate of biogas production. This contributes to challenges in maintaining process stability, thus increasing the risk for process disturbances, including problems that were not commonly encountered before. These difficulties may be particularly pronounced when a broad range of new, largely untested substrates are introduced, leading to an increased heterogeneity of organic material entering the reactors. In the case of currently the most common reactor type; the continuous stirred-tank biogas reactor (CSTBR); such problems may include shifts in rheology (i.e. fluid behaviour) of the anaerobic digester sludge. This may lead to increased energy consumption and decreased digester mixing efficiencies, which in turn may lead to inefficient biogas processes, ultimately decreasing the economic and environmental viability of biogas production. Much is still unknown regarding how rheology shifts happen in biogas reactors, particularly when it comes to what role the substrate plays in rheological dynamics, as compared to the microbial community during varying levels of biogas process stability.

This thesis elucidates the interactions between substrate type, microbial community and its metabolic activity, and anaerobic sludge rheology. A number of sludge samples from mesophilic and thermophilic CSTBRs digesting a broad range of substrates was analysed for their rheology. The specific effects of individual substrate types on CSTBR sludge rheology and the resulting implications for stirring power requirements and mixing efficiency were investigated. In order to also asses to which extent the microbial metabolism affects rheology at different levels of process disturbance, an experiment with a trace-element-induced inhibition of specific metabolic pathways under mesophilic reactor conditions was performed. This was used to identify the sequence of different interactions that occur in the reactor after the process begins to fail, and to evaluate how these interactions link to changes in digester sludge rheology. Finally, a case study of a disturbed thermophilic anaerobic digestion process was performed, including the monitoring of the response of rheology in relation to process stability, which was modified by changing trace element concentrations. The use of artificial substrate without polymeric compounds in both cases allowed for an evaluation of effects of the microbial community and its metabolic products on rheology without including the effects of complex substrates.

The results showed that substrate type has a large effect on how different process parameters correlate with fluid behaviour. This was particularly apparent in the case of total solids and total volatile solids, which correlated well with rheological parameters for samples from reactors digesting agricultural waste, sewage sludge, paper mill waste, or food waste, but not for mesophilic co-digesters. Among the different substrates investigated, food waste was generally observed to lead to the highest limit viscosities (i.e. apparent viscosities at high shear rates, where it becomes linear and constant) of the anaerobic sludge, while digestion of paper mill waste and thermophilic co-digestion led to some of the lowest. No fluid type could be clearly coupled to a specific substrate, but it could be observed that increased solids content could generally be associated with more complex, non-Newtonian rheological behaviour. The differences in fluid characteristics between reactors corresponded to large differences in modelled stirring power requirements and mixing efficiency. The results indicated that fluids with high values of rheological parameters, such as the consistency index (K) or yield stress (τ₀), would likely require more power or an adapted stirring system to achieve complete mixing. The substrates generally contributed more to the rheology characteristics of the anaerobic sludge than microbial cells on their own. Trace element-induced process disturbance initially led to the inhibition of specific microbial groups among methanogenic archaea or their syntrophic partners, which later escalated to broader inhibition of many microbial groups due to the accumulation of fermentation products. This resulted in microbial cell washout with a corresponding decrease of the contribution of the cells to anaerobic sludge rheology. A recovery of the thermophilic anaerobic digestion process was possible after the supplementation of selenium and tungsten was increased, resulting in increased propionate turnover rates, growing cell densities, and higher viscosity. Major shifts in the methanogenic community were observed, corresponding to the level of process stability. It could be concluded based on these experiments that the specific effect of microbial cells and their activity on sludge rheology were linked to cell density, which corresponded to process stability.

A conceptual scheme was developed based on the studies in this thesis, defining complex interactions between substrate, microbial metabolism, and anaerobic sludge rheology in biogas processes. The possible causes of rheology shifts are visualised and discussed.