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  • 1.
    Ajjan Godoy, Fátima Nadia
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Biohybrid Polymer Electrodes for Renewable Energy Storage2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

    List of papers
    1. Biopolymer hybrid electrodes for scalable electricity storage
    Open this publication in new window or tab >>Biopolymer hybrid electrodes for scalable electricity storage
    2016 (English)In: Materials Horizons, ISSN 2051-6347, E-ISSN 2051-6355, Vol. 3, no 3, p. 174-185Article, review/survey (Refereed) Published
    Abstract [en]

    Powering the future, while maintaining a cleaner environment and a strong socioeconomic growth, is going to be one of the biggest challenges faced by mankind in the 21st century. The first step in overcoming the challenge for a sustainable future is to use energy more efficiently so that the demand for fossil fuels can be reduced drastically. The second step is a transition from the use of fossil fuels to renewable energy sources. In this sense, organic electrode materials are becoming increasingly attractive compared to inorganic electrode materials which have reached a plateau regarding performance and have severe drawbacks in terms of cost, safety and environmental friendliness. Using organic composites based on conducting polymers, such as polypyrrole, and abundant, cheap and naturally occurring biopolymers rich in quinones, such as lignin, has recently emerged as an interesting alternative. These materials, which exhibit electronic and ionic conductivity, provide challenging opportunities in the development of new charge storage materials. This review presents an overview of recent developments in organic biopolymer composite electrodes as renewable electroactive materials towards sustainable, cheap and scalable energy storage devices.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2016
    National Category
    Other Environmental Engineering
    Identifiers
    urn:nbn:se:liu:diva-128741 (URN)10.1039/c5mh00261c (DOI)000375296600002 ()
    Note

    Funding Agencies|Knut and Alice Wallenberg Foundation; Wallenberg Scholar grant

    Available from: 2016-05-31 Created: 2016-05-30 Last updated: 2017-11-30
    2. Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material
    Open this publication in new window or tab >>Spectroelectrochemical investigation of redox states in a polypyrrole/lignin composite electrode material
    Show others...
    2015 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, no 24, p. 12927-12937Article in journal (Refereed) Published
    Abstract [en]

    We report spectroelectrochemical studies to investigate the charge storage mechanism of composite polypyrrole/lignin electrodes. Renewable bioorganic electrode materials were produced by electropolymerization of pyrrole in the presence of a water-soluble lignin derivative acting as a dopant. The resulting composite exhibited enhanced charge storage abilities due to a lignin-based faradaic process, which was expressed after repeated electrochemical redox of the material. The in situ FTIR spectroelectrochemistry results show the formation of quinone groups, and reversible oxidation-reduction of these groups during charge-discharge experiments in the electrode materials. The most significant IR bands include carbonyl absorption near 1705 cm(-1), which is attributed to the creation of quinone moieties during oxidation, and absorption at 1045 cm(-1) which is due to hydroquinone moieties.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2015
    National Category
    Materials Chemistry
    Identifiers
    urn:nbn:se:liu:diva-120069 (URN)10.1039/c5ta00788g (DOI)000356022800044 ()
    Note

    Funding Agencies|Knut and Alice Wallenberg foundation; Marie Curie network Renaissance; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [2009-00971]

    Available from: 2015-07-06 Created: 2015-07-06 Last updated: 2017-12-04
    3. High performance PEDOT/lignin biopolymer composites for electrochemical supercapacitors
    Open this publication in new window or tab >>High performance PEDOT/lignin biopolymer composites for electrochemical supercapacitors
    Show others...
    2016 (English)In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 4, no 5, p. 1838-1847Article in journal (Refereed) Published
    Abstract [en]

    Developing sustainable organic electrode materials for energy storage applications is an urgent task. We present a promising candidate based on the use of lignin, the second most abundant biopolymer in nature. This polymer is combined with a conducting polymer, where lignin as a polyanion can behave both as a dopant and surfactant. The synthesis of PEDOT/Lig biocomposites by both oxidative chemical and electrochemical polymerization of EDOT in the presence of lignin sulfonate is presented. The characterization of PEDOT/Lig was performed by UV-Vis-NIR spectroscopy, FTIR infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, cyclic voltammetry and galvanostatic charge-discharge. PEDOT doped with lignin doubles the specific capacitance (170.4 F g(-1)) compared to reference PEDOT electrodes (80.4 F g(-1)). The enhanced energy storage performance is a consequence of the additional pseudocapacitance generated by the quinone moieties in lignin, which give rise to faradaic reactions. Furthermore PEDOT/Lig is a highly stable biocomposite, retaining about 83% of its electroactivity after 1000 charge/discharge cycles. These results illustrate that the redox doping strategy is a facile and straightforward approach to improve the electroactive performance of PEDOT.

    Place, publisher, year, edition, pages
    ROYAL SOC CHEMISTRY, 2016
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:liu:diva-125323 (URN)10.1039/c5ta10096h (DOI)000368839200035 ()
    Note

    Funding Agencies|Power Papers project from the Knut and Alice Wallenberg foundation; Wallenberg Scholar grant from the Knut and Alice Wallenberg foundation; Marie Curie network Renaissance (NA); European Research Council by Starting Grant Innovative Polymers for Energy Storage (iPes) [306250]; Basque Government

    Available from: 2016-02-23 Created: 2016-02-19 Last updated: 2017-11-30
  • 2.
    Baas, Leenard
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Mirata, Murat
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Bio-resource production on the basis of Industrial Ecology in four European harbours, harbour cities and their region2015In: Économie Circulaire et Écosystémes Portuaires (Circular Economy and Port Ecosystems) / [ed] Yann Alix, Nicolas Mat, Juliette Cerceau, Paris: Foundation Sefacil , 2015, 1, p. 223-242Chapter in book (Refereed)
    Abstract [en]

    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. 

  • 3.
    Celander, Filip
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Haglund, Johan
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Energy and nutrient recovery from dairy manure: Process design and economic performance of a farm based system2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    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.

  • 4.
    Ekstrand, Eva-Maria
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Anaerobic digestion in the kraft pulp and paper industry: Challenges and possibilities for implementation2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

    List of papers
    1. Methane potentials of the Swedish pulp and paper industry - A screening of wastewater effluents
    Open this publication in new window or tab >>Methane potentials of the Swedish pulp and paper industry - A screening of wastewater effluents
    Show others...
    2013 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, p. 507-517Article in journal (Refereed) Published
    Abstract [en]

    With the final aim of reducing the energy consumption and increase the methane production at Swedish pulp and paper mills, the methane potential of 62 wastewater effluents from 10 processes at seven pulp and/or paper mills (A-G) was determined in anaerobic batch digestion assays. This mapping is a first step towards an energy efficient and more sustainable utilization of the effluents by anaerobic digestion, and will be followed up by tests in lab-scale and pilot-scale reactors. Five of the mills produce kraft pulp (KP), one thermo-mechanical pulp (TMP), two chemical thermo-mechanical pulp (CTMP) and two neutral sulfite semi-chemical (NSSC) pulp. Both elementary and total chlorine free (ECF and TCF, respectively) bleaching processes were included. The effluents included material from wood rooms, cooking and oxygen delignification, bleaching (often both acid- and alkali effluents), drying and paper/board machinery as well as total effluents before and after sedimentation. The results from the screening showed a large variation in methane yields (percent of theoretical methane potential assuming 940 NmL CH4 per g TOC) among the effluents. For the KP-mills, methane yields above 50% were obtained for the cooking effluents from mills D and F, paper machine wastewater from mill D, condensate streams from mills B, E and F and the composite pre-sedimentation effluent from mill D. The acidic ECF-effluents were shown to be the most toxic to the AD-flora and also seemed to have a negative effect on the yields of composite effluents downstream while three of the alkaline ECF-bleaching effluents gave positive methane yields. ECF bleaching streams gave higher methane yields when hardwood was processed. All TCF-bleaching effluents at the KP mills gave similar degradation patterns with final yields of 10-15% of the theoretical methane potential for four of the five effluents. The composite effluents from the two NSSC-processes gave methane yields of 60% of the theoretical potential. The TMP mill (A) gave the best average yield with all six effluents ranging 40-65% of the theoretical potential. The three samples from the CTMP process at mill B showed potentials around 40% while three of the six effluents at mill G (CTMP) yielded 45-50%.

    Place, publisher, year, edition, pages
    Elsevier, 2013
    Keywords
    Biogas; Anaerobic digestion; Kraft pulp; Chemical thermo-mechanical pulp; Neutral sulfite semi-chemical pulp; Bleaching
    National Category
    Social Sciences
    Identifiers
    urn:nbn:se:liu:diva-104129 (URN)10.1016/j.apenergy.2012.12.072 (DOI)000329377800053 ()
    Available from: 2014-02-07 Created: 2014-02-07 Last updated: 2019-05-07
    2. High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation
    Open this publication in new window or tab >>High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation
    Show others...
    2016 (English)In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 56, p. 166-172Article in journal (Refereed) Published
    Abstract [en]

    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.

    Place, publisher, year, edition, pages
    Elsevier, 2016
    Keywords
    Pulp and paper Anaerobic digestion Sludge recirculation High-rate CSTR Fibre sludge Activated sludge
    National Category
    Renewable Bioenergy Research Production Engineering, Human Work Science and Ergonomics Production Engineering, Human Work Science and Ergonomics Water Engineering
    Identifiers
    urn:nbn:se:liu:diva-131780 (URN)10.1016/j.wasman.2016.06.034 (DOI)000383827700020 ()27453288 (PubMedID)
    Funder
    Swedish Energy Agency
    Note

    Funding agencies: Swedish Energy Agency [32802-1]; Scandinavian Biogas Fuels AB; Poyry AB; BillerudKorsnas AB; SCA; Fiskeby Board AB; Purac AB

    Available from: 2016-10-05 Created: 2016-10-05 Last updated: 2019-05-07Bibliographically approved
    3. Combining high-rate aerobic wastewater treatment with anaerobic digestion of waste activated sludge at a pulp and paper mill
    Open this publication in new window or tab >>Combining high-rate aerobic wastewater treatment with anaerobic digestion of waste activated sludge at a pulp and paper mill
    2018 (English)In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 77, no 8, p. 2068-2076Article in journal (Refereed) Published
    Abstract [en]

    The activated sludge process within the pulp and paper industry is generally run to minimize the production of waste activated sludge (WAS), leading to high electricity costs from aeration and relatively large basin volumes. In this study, a pilot-scale activated sludge process was run to evaluate the concept of treating the wastewater at high rate with a low sludge age. Two 150 L containers were used, one for aeration and one for sedimentation and sludge return. The hydraulic retention time was decreased from 24 hours to 7 hours, and the sludge age was lowered from 12 days to 2–4 days. The methane potential of the WAS was evaluated using batch tests, as well as continuous anaerobic digestion (AD) in 4 L reactors in mesophilic and thermophilic conditions. Wastewater treatment capacity was increased almost four-fold at maintained degradation efficiency. The lower sludge age greatly improved the methane potential of the WAS in batch tests, reaching 170 NmL CH4/g VS at a sludge age of 2 days. In addition, the continuous AD showed a higher methane production at thermophilic conditions. Thus, the combination of high-rate wastewater treatment and AD of WAS is a promising option for the pulp and paper industry.

    Keywords
    Activated sludge, sludge age, anaerobic digestion, biochemical methane potential, CSTR, pulp and paper
    National Category
    Bioprocess Technology
    Identifiers
    urn:nbn:se:liu:diva-146089 (URN)10.2166/wst.2018.120 (DOI)000435663800011 ()29722692 (PubMedID)
    Note

    Funding agencies: Swedish Energy Agency [32802-2]; Scan-dinavian Biogas Fuels AB; Poyry AB; BillerudKorsnas AB; SCA; Fiskeby Board AB; Purac AB

    Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2019-05-07Bibliographically approved
  • 5.
    Ekstrand, Eva-Maria
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Marielle
    Linköping University, Biogas Research Center. Linköping University, Department of Thematic Studies. Linköping University, Faculty of Arts and Sciences. Scandinavian Biogas Fuels AB, Sweden.
    Truong, Xu-Bin
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences.
    Karlsson, Anna
    Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Svensson, Bo H.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Biogas Research Center. Linköping University, Faculty of Arts and Sciences. Scandinavian Biogas Fuels AB, Sweden.
    High-rate anaerobic co-digestion of kraft mill fibre sludge and activated sludge by CSTRs with sludge recirculation2016In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 56, p. 166-172Article in journal (Refereed)
    Abstract [en]

    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.

  • 6.
    Henders, Sabine
    et al.
    Linköping University, The Tema Institute, Department of Water and Environmental Studies. Linköping University, Faculty of Arts and Sciences.
    Palm, Matilda
    Physical Resource Theory, Chalmers University of Technology, Göteborg.
    Englund, Oskar
    Physical Resource Theory, Chalmers University of Technology, Göteborg.
    Sustainability criteria for land use activities in the carbon market2011Report (Other academic)
  • 7.
    Martin, Michael
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Industrial Symbiosis in the Biofuel Industry: Quantification of the Environmental Performance and Identification of Synergies2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

    List of papers
    1. Improving the Environmental Performance of Biofuels with Industrial Symbiosis
    Open this publication in new window or tab >>Improving the Environmental Performance of Biofuels with Industrial Symbiosis
    2011 (English)In: Biomass and Bioenergy, ISSN 0961-9534, Vol. 35, no 5, p. 1747-1755Article in journal (Refereed) Published
    Abstract [en]

    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.

    Place, publisher, year, edition, pages
    Elsevier, 2011
    Keywords
    Industrial Symbiosis, Biogas, Biofuel, Synergies, Industrial Symbiosis, Biogas, Biofuel, Synergies, Industrial Symbiosis, Biogas, Biofuel, Synergies, Industrial Symbiosis, Biogas, Biofuel, Synergies, Industrial Symbiosis, Biogas, Biofuel, Synergies, Industrial Symbiosis, Biogas, Biofuel, Synergies, Industrial Symbiosis, Biogas, Biofuel, Synergies, Industrial Symbiosis, Biogas, Biofuel, Synergies
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:liu:diva-67189 (URN)10.1016/j.biombioe.2011.01.016 (DOI)000290238200017 ()
    Funder
    Formas
    Available from: 2011-04-04 Created: 2011-04-04 Last updated: 2019-06-13
    2. Production synergies in the current biofuel industry: Opportunities for development
    Open this publication in new window or tab >>Production synergies in the current biofuel industry: Opportunities for development
    2012 (English)In: Biofuels, ISSN 1759-7269, E-ISSN 1759-7277, Vol. 3, no 5, p. 545-554Article in journal (Refereed) Published
    Abstract [en]

    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.

    Place, publisher, year, edition, pages
    London: Future Science, 2012
    Keywords
    Biofuels, Synergies, By-product, Industrial Symbiosis
    National Category
    Environmental Sciences
    Identifiers
    urn:nbn:se:liu:diva-84548 (URN)10.4155/bfs.12.52 (DOI)
    Funder
    Formas
    Available from: 2012-10-12 Created: 2012-10-12 Last updated: 2017-12-07
    3. Quantifying the environmental performance of integrated bioethanol and biogas production
    Open this publication in new window or tab >>Quantifying the environmental performance of integrated bioethanol and biogas production
    2014 (English)In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 6, p. 109-116Article in journal (Refereed) Published
    Abstract [en]

    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.

    Place, publisher, year, edition, pages
    Elsevier, 2014
    Keywords
    Ethanol, Biogas, Industrial symbiosis, Environmental impacts, Biofuel, Life cycle assessment
    National Category
    Renewable Bioenergy Research Bioenergy Energy Systems
    Identifiers
    urn:nbn:se:liu:diva-86218 (URN)10.1016/j.renene.2012.09.058 (DOI)000326141000018 ()
    Available from: 2012-12-11 Created: 2012-12-11 Last updated: 2019-06-13
    4. Who gets the benefits? An approach for assessing the environmental performance of industrial symbiosis
    Open this publication in new window or tab >>Who gets the benefits? An approach for assessing the environmental performance of industrial symbiosis
    2015 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 98, p. 263-271Article in journal (Refereed) Published
    Abstract [en]

    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.

    Place, publisher, year, edition, pages
    Elsevier, 2015
    Keywords
    Industrial symbiosis, life cycle assessment, by-product, integration, environmental performance
    National Category
    Environmental Sciences Environmental Engineering Bioenergy Renewable Bioenergy Research
    Identifiers
    urn:nbn:se:liu:diva-90232 (URN)10.1016/j.jclepro.2013.06.024 (DOI)000356194300027 ()
    Available from: 2013-03-21 Created: 2013-03-21 Last updated: 2019-06-13Bibliographically approved
    5. Using LCA to quantify the environmental performance of an industrial symbiosis network: Application in the Biofuels Industry
    Open this publication in new window or tab >>Using LCA to quantify the environmental performance of an industrial symbiosis network: Application in the Biofuels Industry
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    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.

    Keywords
    Industrial symbiosis, life cycle assessment, by-product, integration, environmental performance
    National Category
    Environmental Sciences Environmental Engineering Renewable Bioenergy Research Bioenergy
    Identifiers
    urn:nbn:se:liu:diva-90229 (URN)
    Available from: 2013-03-21 Created: 2013-03-21 Last updated: 2018-01-11
  • 8.
    Martin, Michael
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Using LCA to quantify the environmental performance of an industrial symbiosis network: Application in the Biofuels IndustryManuscript (preprint) (Other academic)
    Abstract [en]

    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.

  • 9.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Parsapour, Amin
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Upcycling wastes with biogas production:: An exergy and economic analysis2012In: Venice 2012: International Symposium on Energy from Biomass and Waste, Venice, Italy, 2012Conference paper (Other academic)
    Abstract [en]

    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.

  • 10.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Who gets the benefits? An approach for assessing the environmental performance of industrial symbiosis2015In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 98, p. 263-271Article in journal (Refereed)
    Abstract [en]

    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.

  • 11.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Fonseca, Jorge
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Quantifying the environmental performance of integrated bioethanol and biogas production2014In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 6, p. 109-116Article in journal (Refereed)
    Abstract [en]

    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.

  • 12.
    Mirata, Murat
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Gundberg, Andreas
    Lantmännen Agroetanol AB, Norrköping.
    Industrial symbiosis and biofuels industry: Business value and organisational factors within cases of ethanol and biogas production2017Report (Other academic)
    Abstract [en]

    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. 

  • 13.
    Moestedt, J.
    et al.
    Linköping University, Biogas Research Center. Department of R&D Biogas, Tekniska verken i Linköping AB, Linköping, Sweden; Department of Microbiology, BioCenter, University of Agricultural Sciences, Uppsala, Sweden.
    Nordell, E.
    Linköping University, Biogas Research Center. Department of R&D Biogas, Tekniska verken i Linköping AB, Linköping, Sweden.
    Shakeri Yekta, Sepehr
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Lundgren, J.
    Linköping University, Biogas Research Center. Department of R&D Biogas, Tekniska verken i Linköping AB, Linköping, Sweden.
    Marti, M.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Sundberg, Carina
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Ejlertsson, Jörgen
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Scandinavian Biogas Fuels AB, Sweden.
    Svensson, Bo
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Björn, Annika
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center.
    Effects of trace element addition on process stability during anaerobic co-digestion of OFMSW and slaughterhouse waste2016In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 47, no Pt A, p. 11-20Article in journal (Refereed)
    Abstract [en]

    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.

  • 14.
    Wetterlund, Elisabeth
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Pettersson, Karin
    Chalmers University of Technology.
    Mossberg, Johanna
    SP Technical Research Institute of Sweden .
    Torén, Johan
    SP Technical Research Institute of Sweden .
    Hoffstedt, Christian
    Innventia, Stockholm.
    von Schenck, Anna
    Innventia, Stockholm.
    Berglin, Niklas
    Innventia, Stockholm.
    Lundmark, Robert
    Luleå University of Technology.
    Lundgren, Joakim
    Luleå University of Technology.
    Leduc, Sylvain
    International Institute of Applied Systems Analysis (IIASA).
    Kindermann, Georg
    International Institute of Applied Systems Analysis (IIASA).
    Optimal localisation of next generation biofuel production in Sweden2013Report (Other academic)
    Abstract [en]

    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.

  • 15.
    Šafarič, Luka
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences.
    Anaerobic Digester Fluid Rheology and Process Efficiency: Interactions of Substrate Composition, Trace Element Availability, and Microbial Activity2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    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.

    List of papers
    1. Substrate and operational conditions as regulators of fluid properties in full-scale continuous stirred-tank biogas reactors - implications for rheology-driven power requirements
    Open this publication in new window or tab >>Substrate and operational conditions as regulators of fluid properties in full-scale continuous stirred-tank biogas reactors - implications for rheology-driven power requirements
    Show others...
    2018 (English)In: Water Science and Technology, ISSN 0273-1223, E-ISSN 1996-9732, Vol. 78, no 4, p. 814-826Article in journal (Refereed) Published
    Abstract [en]

    Understanding fluid rheology is important for optimal design and operation of continuous stirred-tank biogas reactors (CSTBRs) and is the basis for power requirement estimates. Conflicting results have been reported regarding the applicability of total solid (TS) and/or total volatile solid (TVS) contents of CSTBR fluids as proxies for rheological properties. Thus, the present study investigates relationships between rheological properties of 12 full-scale CSTBR fluids, their substrate profiles, and major operational conditions, including pH, TS and TVS contents, organic loading rate, hydraulic retention time, and temperature. Rheology-driven power requirements based on various fluid characteristics were evaluated for a general biogas reactor setup. The results revealed a significant correlation only between the rheological fluid properties and TS or TVS contents for sewage sludge digesters and thermophilic co-digesters (CD), but not for mesophilic CD. Furthermore, the calculated power requirements for pumping and mixing, based on the various fluid characteristics of the studied CSTBRs, varied broadly irrespective of TS and TVS contents. Thus, this study shows that the TS and/or TVS contents of digester fluid are not reliable estimators of the rheological properties in CSTBRs digesting substrates other than sewage sludge.

    Place, publisher, year, edition, pages
    IWA PUBLISHING, 2018
    Keywords
    anaerobic digestion; biogas; continuous stirred-tank biogas reactor; power requirement; rheology; viscosity
    National Category
    Other Electrical Engineering, Electronic Engineering, Information Engineering
    Identifiers
    urn:nbn:se:liu:diva-151955 (URN)10.2166/wst.2018.352 (DOI)000445519000010 ()30252659 (PubMedID)
    Note

    Funding Agencies|Innovation Agency (VINNOVA), Sweden [2008-139]; Scandinavian Biogas Fuels AB, Sweden; European Unions Seventh Framework ATBEST Marie-Curie ITN program [316838]; Biogas Research Center; Research Council for Environment, Agricultural Sciences and Spatial Planning (FORMAS), Sweden; Linkoping University; Swedish Energy Agency [35624-2]

    Available from: 2018-10-16 Created: 2018-10-16 Last updated: 2019-04-02
    2. Dynamics of a Perturbed Microbial Community during Thermophilic Anaerobic Digestion of Chemically Defined Soluble Organic Compounds
    Open this publication in new window or tab >>Dynamics of a Perturbed Microbial Community during Thermophilic Anaerobic Digestion of Chemically Defined Soluble Organic Compounds
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    2018 (English)In: MICROORGANISMS, ISSN 2076-2607, Vol. 6, no 4, article id 105Article in journal (Refereed) Published
    Abstract [en]

    Knowledge of microbial community dynamics in relation to process perturbations is fundamental to understand and deal with the instability of anaerobic digestion (AD) processes. This study aims to investigate the microbial community structure and function of a thermophilic AD process, fed with a chemically defined substrate, and its association with process performance stability. Next generation amplicon sequencing of 16S ribosomal RNA (rRNA) genes revealed that variations in relative abundances of the predominant bacterial species, Defluviitoga tunisiensis and Anaerobaculum hydrogeniformans, were not linked to the process performance stability, while dynamics of bacterial genera of low abundance, Coprothermobacter and Defluviitoga (other than D. tunisiensis), were associated with microbial community function and process stability. A decrease in the diversity of the archaeal community was observed in conjunction with process recovery and stable performance, implying that the high abundance of specific archaeal group(s) contributed to the stable AD. Dominance of hydrogenotrophic Methanoculleus particularly corresponded to an enhanced microbial acetate and propionate turnover capacity, whereas the prevalence of hydrogenotrophic Methanothermobacter and acetoclastic Methanosaeta was associated with instable AD. Acetate oxidation via syntrophic interactions between Coprothermobacter and Methanoculleus was potentially the main methane-formation pathway during the stable process. We observed that supplementation of Se and W to the medium improved the propionate turnover by the thermophilic consortium. The outcomes of our study provided insights into the community dynamics and trace element requirements in relation to the process performance stability of thermophilic AD.

    Place, publisher, year, edition, pages
    MDPI, 2018
    Keywords
    Thermophilic Anaerobic Digestion; process perturbation; process stability; microbial community dynamics; trace elements
    National Category
    Microbiology
    Identifiers
    urn:nbn:se:liu:diva-154125 (URN)10.3390/microorganisms6040105 (DOI)000455073000010 ()30314333 (PubMedID)
    Note

    Funding Agencies|European Unions Seventh Framework ATBEST Marie-Curie ITN program [316838]; Linkoping University; Swedish Energy Agency [35624-2]; Biogas Research Center

    Available from: 2019-01-29 Created: 2019-01-29 Last updated: 2019-04-02
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