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  • 1. Ahlgren, S.
    et al.
    Röös, E.
    Di Lucia, L.
    Sundberg, Cecilia
    Hansson, P. -A
    EU sustainability criteria for biofuels: Uncertainties in GHG emissions from cultivation2012In: Biofuels, ISSN 1759-7269, E-ISSN 1759-7277, Vol. 3, no 4, p. 399-411Article in journal (Refereed)
    Abstract [en]

    Background: Cultivation of raw material represents a large proportion of biofuelś GHG emissions. The EU renewable energy directive 2009/28/EC specifies a GHG emission default value for cultivation of biofuel raw material (23 g CO2-e/MJ ethanol for wheat). The aim of this study was to quantify the uncertainty in GHG emissions for wheat cultivation in Sweden, considering uncertainty and variability in data at farm level. Results: Two levels of data collection at farm level were analyzed; simple (only yield and amount of N) and advanced (also including amounts and types of energy). The 2.5-97.5 percentile uncertainty for Swedish winter wheat was 20-27 g CO 2-e/MJ, which can be considered large in the context of the Directives threshold of 23 g (to two significant figures). Conclusion: It is concluded that quantifying GHG emissions in order to regulate biofuels is a difficult task, especially emissions from cultivation, since these are biological systems with large variability.

  • 2.
    Asperö Lind, Mikael
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Biologisk behandling av matavfall med avfallskvarn: En systemanalys2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The municipal sewage treatment plant Käppalaverket and municipally owned waste handling company SÖRAB, both located in the northern part of Stockholm Sweden, have together started the BOA project. BOA means “Biologisk behandling av Organiskt matavfall medhjälp av Avfallskvarnar” which is translated to biological treatment of organic food waste using food waste macerators. The initiative stems from one of Sweden’s national environmental goals: Saying that at least 35 percent of all the organic waste produced byhouseholds and companies shall be treated biologically by the year 2010 and that the nutrients from this waste should be used as fertilizer.

    In the first phase of the project, seven different scenarios on how to transport the food waste from the households to the digestion chamber were described. To be able to evaluate these scenarios from a societal and sustainability perspective, seven criteria were chosen:technology, environment, work environment, economy, quality, law, and acceptance. The first part of the thesis consisted of formulating indicators from these criteria, through meetings and discussions with different working groups, all consisting of people in the waste and wastewater field. After that, a review of available tools was done to find the ones that were best suited for each chosen indicator.

    For the indicators that required calculations, Substance Flow Analysis, Life Cycle Analysis, Energy Analysis and Life Cycle Costing were chosen. After the tools had been used the results were given grades depending on how big impact they would have on society. For some of the indicators calculations were not possible and instead a qualitative grading system was used, in which the different working groups graded each scenario depending on the indicator and the grades were weighted and summed together.

    Finally, a multi criteria analysis was made together with the project managers from Käppalaverket and SÖRAB, in which the different indicators were discussed and weighted depending on how important they were considered to be. The final result of the multi criteria analysis was that one scenario could be chosen as the most suited for transport of food waste, from the perspective of the chosen indicators and their given weight.

    The scenario in which food waste is collected in bins and then transported by car to a centralprocessing plant, and finally transported by car to Käppalaverkets digestion chambers, got the highest score in the multi criteria analysis and is therefore the best scenario from the perspective of the chosen indicators and given weight. But from the multi criteria analysis onecould also see that none of the scenarios were given a particularly low score. This opens upfor the possibility of combined scenarios were all the residents of the SÖRAB region are given the possibility to recycle their food waste with a bin collecting system, but were there isa will to use systems with a kitchen food waste disposer instead it can be accepted as long as they do not become too popular.

    During the work of this thesis several questions have been raised that needs further investigation. One is what happens with the food waste when it is transported in the sewagesystem and another is how it will change during storage longer than four days. Also, the final results have shown that the impact on climate change from the scenarios could besignificantly decreased if a leakage free methane production could be assured and the possibility to use renewable fuels for the collecting cars was investigated.

  • 3. Cerutti, P. O.
    et al.
    Sola, P.
    Chenevoy, A.
    Iiyama, M.
    Yila, J.
    Zhou, W.
    Djoudi, H.
    Atyi, R. E.
    Gautier, D. J.
    Gumbo, D.
    Kuehl, Y.
    Levang, P.
    Martius, C.
    Matthews, R.
    Nasi, R.
    Neufeldt, H.
    Njenga, M.
    Petrokofsky, G.
    Saunders, M.
    Shepherd, G.
    Sonwa, D. J.
    Sundberg, Cecilia
    Van Noordwijk, M.
    The socioeconomic and environmental impacts of wood energy value chains in Sub-Saharan Africa: A systematic map protocol2015In: Environmental Evidence, ISSN 2047-2382, E-ISSN 2047-2382, Vol. 4, no 1, article id 4Article in journal (Refereed)
    Abstract [en]

    Background: The vast majority of households in Sub-Saharan Africa (SSA) depend on wood energy - comprising firewood and charcoal - for their daily energetic needs. Such consumption trends are expected to remain a common feature of SSA's wood energy production and supply chains, at least in the short- to medium-terms. Notwithstanding its importance, wood energy generally has low priority in SSA national policies. However, the use of wood energy is often considered a key driver of unsustainable management and negative environmental consequences in the humid and dry forests. To date, unsystematic assessments of the socio-economic and environmental consequences of wood energy use have underplayed its significance, thus further hampering policy debates. Therefore, a more balanced approach which considers both demand and supply dynamics is needed. This systematic map aims at providing a comprehensive approach to understanding the role and impacts of wood energy across all regions and aspects in SSA. Methods: The objective of this systematic map is to collate evidence from studies of environmental and socio-economic impacts of wood energy value chains, by considering both demand and supply within SSA. The map questions are framed using a Populations, Exposure, Comparators and Outcomes (PECO) approach. We name the supply and demand of wood energy as the "exposure," composed of wood energy production, harvesting, processing, and consumption. The populations of interest include both the actors involved in these activities and the forest sites where these activities occur. The comparator is defined as those cases where the same wood energy activities occur with i) available/accessible alternative energy sources, ii) regulatory frameworks that govern the sector and iii) alternative technologies for efficient use. The outcomes of interest encompass both socioeconomic and environmental impacts that can affect more than the populations named above. For instance, in addition to the direct socioeconomic impacts felt by participants in the wood energy value chain, forest dwellers may experience livelihood changes due to forest degradation caused by external harvesters. Moreover, intensified deforestation in one area may concurrently lead to forest regeneration in another.

  • 4. Corbin, Kendall R.
    et al.
    Hsieh, Yves S. Y.
    University of Adelaide, Australia.
    Betts, Natalie S.
    Byrt, Caitlin S.
    Henderson, Marilyn
    Stork, Jozsef
    DeBolt, Seth
    Fincher, Geoffrey B.
    Burton, Rachel A.
    Grape marc as a source of carbohydrates for bioethanol: Chemical composition, pre-treatment and saccharification.2015In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 193, p. 76-83, article id S0960-8524(15)00816-0Article in journal (Refereed)
    Abstract [en]

    Global grape production could generate up to 13 Mt/yr of wasted biomass. The compositions of Cabernet Sauvignon (red marc) and Sauvignon Blanc (white marc) were analyzed with a view to using marc as raw material for biofuel production. On a dry weight basis, 31-54% w/w of the grape marc consisted of carbohydrate, of which 47-80% was soluble in aqueous media. Ethanol insoluble residues consisted mainly of polyphenols, pectic polysaccharides, heteroxylans and cellulose. Acid and thermal pre-treatments were investigated for their effects on subsequent cellulose saccharification. A 0.5M sulfuric acid pre-treatment yielded a 10% increase in the amount of liberated glucose after enzymatic saccharification. The theoretical amount of bioethanol that could be produced by fermentation of grape marc was up to 400 L/t. However, bioethanol from only soluble carbohydrates could yield 270 L/t, leaving a polyphenol enriched fraction that may be used in animal feed or as fertilizer.

  • 5.
    Egeskog, Andrea
    et al.
    Chalmers University, Energy and Environment.
    Barretto, Alberto
    Brazilian Bio-ethanol Science and Technology Laboratory(CTBE).
    Berndes, Göran
    Chalmers University, Energy and Environment.
    Freitas, Flavio L. M.
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Holmén, Magnus
    echnology Management and Economics and connected to Center for Business Innovation.
    Sparovek, G.
    Torén, Johan
    SP Technical Research Institute of Sweden.
    Actions and opinions of Brazilian farmers who shift to sugarcane: an interview-based assessment with discussion of implications for land-use change2016In: Land use policy, ISSN 0264-8377, E-ISSN 1873-5754, Vol. 57, p. 594-604Article in journal (Refereed)
    Abstract [en]

    Sugarcane ethanol systems can deliver large greenhouse gas emissions savings if emissions associated with land-use change are kept low. This qualitative study documents and analyzes actions and opinions among Brazilian farmers who shift to sugarcane production. Semi-structured interviews were held with 28 actors associated with sugarcane production in three different regions: one traditional sugarcane region and two regions where sugarcane is currently expanding. Most farmers considered sugarcane a land diversification option with relatively low economic risk, although higher risk than their previous land use. Beef production was considered a low-risk option, but less profitable than sugarcane. In conjunction with converting part of their land to sugarcane, most farmers maintained and further intensified their previous agricultural activity, often beef production. Several farmers invested in expanded production in other regions with relatively low land prices. Very few farmers in the expansion regions shifted all their land from the former, less profitable, use to sugarcane. Very few farmers in this study had deforested any land in connection with changes made when shifting to sugarcane. The respondents understand "environmental friendliness" as compliance with the relevant legislation, especially the Brazilian Forest Act, which is also a requirement for delivering sugarcane to the mills. Indirect land-use change is not a concern for the interviewed farmers, and conversion of forests and other native vegetation into sugarcane plantations is uncontroversial if legal. We derive hypotheses regarding farmers' actions and opinions from our results. These hypotheses aim to contribute to better understanding of what takes place in conjunction with expansion of sugarcane and can, when tested further, be of use in developing, e.g., policies for iLUC-free biofuel production.

  • 6. Ericsson, N.
    et al.
    Porsö, C.
    Åhlgren, S.
    Nordberg, Å.
    Sundberg, Cecilia
    Hansson, P. -A
    Time-dependent climate impact of a bioenergy system - methodology development and application to Swedish conditions2013In: Global Change Biology Bioenergy, ISSN 1757-1693, E-ISSN 1757-1707, Vol. 5, no 5, p. 580-590Article in journal (Refereed)
    Abstract [en]

    The area of dedicated energy crops is expected to increase in Sweden. This will result in direct land use changes, which may affect the carbon stocks in soil and biomass, as well as yield levels and the use of inputs. Carbon dioxide (CO2) fluxes of biomass are often not considered when calculating the climate impact in life cycle assessments (LCA) assuming that the CO2 released at combustion has recently been captured by the biomass in question. With the extended time lag between capture and release of CO2inherent in many perennial bioenergy systems, the relation between carbon neutrality and climate neutrality may be questioned. In this paper, previously published methodologies and models are combined in a methodological framework that can assist LCA practitioners in interpreting the time-dependent climate impact of a bioenergy system. The treatment of carbon differs from conventional LCA practice in that no distinction is made between fossil and biogenic carbon. A time-dependent indicator is used to enable a representation of the climate impact that is not dependent on the choice of a specific characterization time horizon or time of evaluation and that does not use characterization factors, such as global warming potential and global temperature potential. The indicator used to aid in the interpretation phase of this paper is global mean surface temperature change (ΔTs(n)). A theoretical system producing willow for district heating was used to study land use change effects depending on previous land use and variations in the standing biomass carbon stocks. When replacing annual crops with willow this system presented a cooling contribution to ΔTs(n). However, the first years after establishing the willow plantation it presented a warming contribution to ΔTs(n). This behavior was due mainly to soil organic carbon (SOC) variation. A rapid initial increase in standing biomass counteracted the initial SOC loss.

  • 7. Gandiglio, M.
    et al.
    Lanzini, A.
    Soto, A.
    Leone, P.
    Santarelli, Massimo
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. University of Illinois at Chicago, United States.
    Enhancing the energy efficiency of wastewater treatment plants through co-digestion and fuel cell systems2017In: Frontiers in Environmental Science, ISSN 2296-665X, Vol. 5, article id 70Article, review/survey (Refereed)
    Abstract [en]

    The present work provides an overview of technological measures to increase the self-sufficiency of wastewater treatment plants (WWTPs), in particular for the largely diffused activated sludge-based WWTP. The operation of WWTPs entails a huge amount of electricity. Thermal energy is also required for pre-heating the sludge and sometimes exsiccation of the digested sludge. On the other hand, the entering organic matter contained in the wastewater is a source of energy. Organic matter is recovered as sludge, which is digested in large stirred tanks (anaerobic digester) to produce biogas. The onsite availability of biogas represents a great opportunity to cover a significant share of WWTP electricity and thermal demands. Especially, biogas can be efficiently converted into electrical energy (and heat) via high temperature fuel cell generators. The final part of this work will report a case study based on the use of sewage biogas into a solid oxide fuel cell. However, the efficient biogas conversion in combined heat and power (CHP) devices is not sufficient. Self-sufficiency requires a combination of efficient biogas conversion, the maximization the yield of biogas from the organic substrate, and the minimization of the thermal duty connected to the preheating of the sludge feeding the anaerobic digester (generally achieved with pre-thickeners). Finally, the co-digestion of the organic fraction of municipal solid waste (OFMSW) into digesters treating sludge from WWTPs represent an additional opportunity for increasing the biogas production of existing WWTPs, thus helping the transition toward self-sufficient plants.

  • 8.
    Göransson, Malena
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    OXIDATIV FÖRBEHANDLING AV MESOFILT RÖTAT SLAM FÖR ÖKAD BIOGASPRODUKTION2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis which was conducted in 2011 at the Käppala wastewater treatment plant (WWTP) has investigated the possibility to use the chemical conditioning process KemiCond® as a pre-treatment method to anaerobic digestion for increased biogas production. A previous investigation showed that sludge treated with the Kemicond process has a higher gas potential than untreated sludge. The experiment was conducted using a lab scale batch process. The influence of the unfavourable conditions (low alkalinity, low pH and high sulphate concentration) caused by the Kemicond-process were however not investigated. The objective of this master thesis was thus to further examine these previous results.

    In this master thesis two lab scale experiments have been conducted, one batch and one continuous. In the batch experiment two different concentrations of wet and dewatered Kemicond treated sludge were investigated. Untreated sludge from the anaerobic digesterR200 at Käppala waste water treatment plant was used as a reference and also to dilute the Kemicond treated sludge to the desired dry matter concentration. The experiment showed that both wet and dewatered sludge resulted in a faster gas production in the beginning of the anaerobic digestion, and for the dewatered sludge the amount of gas produced exceeded that of the reference. In the experiment with the wet Kemicond treated sludge the gas production decreased or halted after the initial faster phase.

    In the continuous experiment the concentration of dewatered sludge which gave the best result in the batch experiment was used. Sludge from R200 was used as a reference. The results indicated that the gas production increased in the reactor with the dewatered sludge compared to the reference. A stable process was obtained.

    A rough calculation has been performed to investigate a possible process layout in full scale. This showed that the largest benefits except for the increased biogas production are associated with a decreased use of chemicals when less sludge is treated with the Kemicond process.

  • 9. Hammar, T.
    et al.
    Ericsson, N.
    Sundberg, Cecilia
    Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden.
    Hansson, P. -A
    Climate Impact of Willow Grown for Bioenergy in Sweden2014In: Bioenergy Research, ISSN 1939-1234, Vol. 7, no 4, p. 1529-1540Article in journal (Refereed)
    Abstract [en]

    Short-rotation coppice willow (SRCW) is a fast-growing and potentially high-yielding energy crop. Transition to bioenergy has been identified in Sweden as one strategy to mitigate climate change and decrease the current dependency on fossil fuel. In this study, life cycle assessment was used to evaluate and compare the climate impacts of SRCW systems, for the purpose of evaluating key factors influencing the climate change mitigation potential of SRCW grown on agricultural land in Sweden. Seven different scenarios were defined and analysed to identify the factors with the most influence on the climate. A carbon balance model was used to model carbon fluxes between soil, biomass and atmosphere under Swedish growing conditions. The results indicated that SRCW can act as a temporary carbon sink and therefore has a mitigating effect on climate change. The most important factor in obtaining a high climate change-mitigating effect was shown to be high yield. Low yield gave the worst mitigating effect of the seven scenarios, but it was still better than the effect of the reference systems, district heating produced from coal or natural gas.

  • 10. Hammar, T.
    et al.
    Hansson, P. -A
    Sundberg, Cecilia
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    Climate impact assessment of willow energy from a landscape perspective: A Swedish case study2017In: Global Change Biology Bioenergy, ISSN 1757-1693, E-ISSN 1757-1707, Vol. 9, no 5, p. 973-985Article in journal (Refereed)
    Abstract [en]

    Locally produced bioenergy can decrease the dependency on imported fossil fuels in a region, while also being valuable for climate change mitigation. Short-rotation coppice willow is a potentially high-yielding energy crop that can be grown to supply a local energy facility. This study assessed the energy performance and climate impacts when establishing willow on current fallow land in a Swedish region with the purpose of supplying a bio-based combined heat and power plant. Time-dependent life cycle assessment (LCA) was combined with geographic information system (GIS) mapping to include spatial variation in terms of transport distance, initial soil organic carbon content, soil texture and yield. Two climate metrics were used [global warming potential (GWP) and absolute global temperature change potential (AGTP)], and the energy performance was determined by calculating the energy ratio (energy produced per unit of energy used). The results showed that when current fallow land in a Swedish region was used for willow energy, an average energy ratio of 30 MJ MJ-1 (including heat, power and flue gas condensation) was obtained and on average 84.3 Mg carbon per ha was sequestered in the soil during a 100-year time frame (compared with the reference land use). The processes contributing most to the energy use during one willow rotation were the production and application of fertilizers (~40%), followed by harvest (~35%) and transport (~20%). The temperature response after 100 years of willow cultivation was -6·10-16K MJ-1 heat, which is much lower compared with fossil coal and natural gas (70·10-16K MJ-1 heat and 35·10-16 K MJ-1 heat, respectively). The combined GIS and time-dependent LCA approach developed here can be a useful tool in systematic analysis of bioenergy production systems and related land use effects.

  • 11.
    Johnson, Francis X
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Diaz-Chavez, Rocio
    Imperial College London.
    Israilava, Alesia
    Swedish Energy Agency.
    Rosillo-Calle, Frank
    Imperial College London.
    Takama, Takeshi
    Japan International Cooperation Agency.
    Tella, Patricia
    Stockholm Environment Institute.
    The Achievable Potential of Wood Fuels for Climate Mitigation at Regional and Global Levels: Reviewing the Scope for Technical, Economic and Financial Implementation2010In: Proceedings of the 18th European Biomass Conference and Exhibition / [ed] WIP/ETA, 2010Conference paper (Other academic)
    Abstract [en]

    Bioenergy from wood is the oldest energy source but at the same time there are new opportunities for wood energy to make substantial contributions to climate mitigation while also helping to improve the quality of energy services and contribute to development and energy security objectives. The potential for wood fuels for climate mitigation in the near-term are probably concentrated in the area of biomass co-firing with coal, due to the low cost and the major growth in coal-fired generation in countries such as China. There are also options for climate mitigation in the traditional biomass sector, through improved stoves and through more efficient charcoal production. Other options include substitution for coal in steel-making. The socio-economic implications are somewhat complex compared to other energy sources, since they relate closely to rural development but also create new allied industries, such as the wood pellets industry. Financial aspects in terms of carbon finance can be distinguished by the relatively straightforward case of larger-scale substitution projects vs. the complex small projects that are more difficult to measure and monitor.

  • 12.
    Johnson, Francis X.
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Virgin, Ivar
    Stockholm Environment Institute.
    Future Trends in markets for food, feed, fibre and fuel2010In: Food versus Fuel: An informed introduction to biofuels / [ed] Frank Rosillo-Calle and Francis X. Johnson, London: Zed Books, 2010Chapter in book (Other academic)
    Abstract [en]

    A fundamental transformation is underway in the use of biomass resources for food, feed, fuel, fibre and many other uses. This transformation arises from the combination of three key drivers over the coming decades: the need to substitute renewable resources for the non-renewable ones on which economic growth has been predicated; the need to adapt to a changing climate by using resources more wisely and investing in the technology for biofuels that are carbon-negative; and the resource requirements of a growing world population with increasing demands for food, feed and fuel. There is wide scope for reconciling expanded biofuel production with food security and even for deploying biofuels in a way that support sustainable development and helps to revive rural economies. In order to realise the potential for synergies rather than conflicts between food and fuel, substantial investment in research and development is needed, as is a rejection of subsidies for unsustainable agricultural practices and a wide adoption of policies that support integrated and highly productive biomass platforms. Future trends in demand and supply reveal the importance of avoiding the view that food security and biofuel development are competing objectives: the biomass resources that support food and fuel—as well as feed, fibre, fertiliser and other uses—can and must be used synergistically to address the energy and climate challenge of the coming decades.

  • 13.
    Jonsson, Daniel
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Gårdsverk i Skåne2012Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    45 metre high, 45 kW wind turbines are small enough to be considered small-scale wind power under Swedish regulations (requiring only a simple building permit), but powerful enough to significantly reduce the energy bill for a large farm.

    Several actors on the market have identified this business opportunity, and there seems to be an interest from potential customers. But how well does this new type of turbine align with municipal planning goals? Is it possible to get permits for them?

    In this thesis, the conditions for building these turbines in all 33 municpipalities in the county of Scania in southern Sweden are discussed. After an initial investment appraisal, wind, landscape and market conditions are discussed to determine where one might want to erect these turbines.

    Then, focus is shifted towards where it would possible to get a permit. The comprehensive plans of the municipalities are compared to the permits they have granted. This is supplemented by interviews where possible.

    Finally, everything is compiled and a few distinct areas emerge. The forest in the north­eastern parts of the county makes the turbines unprofitable. With a few exceptions, the southern part of the county is an excellent place to market these turbines while the political question seems to remain open in the northwest.

  • 14.
    Kantarelis, Efthymios
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Blasiak, Wlodzimierz
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Biomass pyrolysis  for energy and fuels production2013In: Technologies for Converting Biomass to Useful Energy: Combustion, Gasification, Pyrolysis, Torrefaction and Fermentation / [ed] Erik Dahlquist, CRC Press, 2013, p. 245-277Chapter in book (Refereed)
  • 15.
    Karlsson, Sara
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Sustainable use of Baltic Sea natural resources based on ecological engineering and biogas production: System analysis and case study Trelleborg2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Eutrophication is one of the most serious environmental problems in the Baltic Sea due to factors such as nutrient discharges from different sources and long residence time. Eutrophication gives rise to increased primary production, often followed by oxygen depletion and disruption of important ecosystems. An action plan has been created by the Helsinki Commission (HELCOM) in order to achieve good ecological status of the Baltic Sea in the year of 2021. According to the action plan, 21 000 tonnes of nitrogen and 290 tonnes of phosphorus shall be decreased of the annual discharge from Sweden.

    The aim of methods within ecological engineering is to solve environmental problems, and the applications ranging from the harvesting of existing ecosystems to the construction of new ecosystems. This study evaluates if harvest of algae, reed, and mussels can help meeting the goals of the action plan considerably, in accordance with areas and biomass amounts that need to be harvested, and to assess the efficiency of the three biomasses with regards to nutrient reduction. The potential of harvested biomasses as substrates in biogas production and as fertilizers is investigated, and how much fossil CO2 that can be saved from being released to the atmosphere if net energy benefits, calculated from energy budgets in the biogas process, replaces fossil fuels.

    Life cycle inventories which extend from the harvest (i.e. from the Baltic coast of Sweden) to the production of biogas have been made in order to investigate the biogas potential of algal, reed, and mussel biomass. Suitability of the three biomasses as fertilizers has been assessed through comparison between nutrient sufficiency of crops and nutrient contents of the three biomasses (i.e. based on quotients of nitrogen).

    The quantity of biomass in the areas that can be harvested can help meeting the goals of the action plan drawn up by HELCOM, and mussels show to be most efficient with regards to nutrient reduction efficiency. Reed has the highest net energy benefit followed by algae, and both biomasses show potential of further investigation as substrates in the biogas production process. Mussels have low net energy benefit and thus are not a suitable substrate in biogas production. The three biomasses are suitable as fertilizers with respect to contents of nitrogen but the content of phosphorus occurs under the sufficiency levels for the crops (i.e. peas, grain, and sugar beets). For algae and reed, the potassium contents occur above the sufficiency level for peas and grain but under the level for sugar beets, mussels contain lower levels of potassium than the need of the investigated crops.

  • 16.
    Khan, Ershad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Mainali, Brijesh
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Techno-Economic Analysis of Small Scale Biogas Based Poly generation Systems in Bangladesh2012Conference paper (Other academic)
    Abstract [en]

    Access to electricity, clean drinking water andclean cooking gas services are genuine needs of the rural poor in order to improvetheir living conditions. One can think of addressing these needs individually orinstead use an integrated approach. Looking for solutions using a holisticapproach should always have a better impact. A small scale and distributedbiogas based poly generation system could be an effective solution to bringsustainable development to remote and rural areas of Bangladesh. Biogasdigesters are a popular and promising rural energy technology and the integrationof biogas production with power generation and water purification is aninnovative approach. This paper discusses such an integrated poly generationsystem and analyzes the techno-economic performance of the scheme for meetingthe demand of electricity, cooking energy and safe drinking water of 30households in a rural village of Bangladesh. The mass flows and energy balance,life cycle cost (levelized cost) of producing electricity, cooking gas and safedrinking water as well as the payback period of such a poly generation system wereestimated. In this study, it has been found that this poly generation system ismuch more competitive and promising than other available technologies whenattempting to solve the energy and arsenic-related problems in Bangladesh. Thedeterminant factors influencing the performance of the system and their impacton the cost have been looked at under different conditions. This paper willserve as a background paper in order to expand research further in thedirection of making biogas based poly generation system as a successfulbusiness solution in rural areas.

  • 17.
    Khatiwada, Dilip
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Optimizing ethanol and bioelectricity production in sugarcane biorefineries in Brazil2012Report (Other academic)
  • 18.
    Khatiwada, Dilip
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS. International Institute for Applied Systems Analysis (IIASA), Austria.
    Sylvain, Leduc
    Ecosystems Services & Management (ESM) program, International Institute for Applied Systems Analysis (IIASA), Austria.
    McCallum, Ian
    Ecosystems Services & Management (ESM) program, International Institute for Applied Systems Analysis (IIASA), Austria.
    Silveira, Semida
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Optimizing second generation bioethanol production in sugarcane biorefineries in Brazil2012Conference paper (Refereed)
  • 19. Kimming, M.
    et al.
    Sundberg, Cecilia
    Swedish University of Agricultural Sciences, Sweden.
    Nordberg, A.
    Hansson, P. -A
    Vertical integration of local fuel producers into rural district heating systems: Climate impact and production costs2015In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 78, p. 51-61Article in journal (Refereed)
    Abstract [en]

    Farmers can use their own agricultural biomass residues for heat production in small-scale systems, enabling synergies between the district heating (DH) sector and agriculture. The barriers to entry into the Swedish heat market were extremely high as long as heat distribution were considered natural monopoly, but were recently lowered due to the introduction of a regulated third party access (TPA) system in the DH sector. This study assesses the potential impact on greenhouse gas emissions and cost-based heat price in the DH sector when farmers vertically integrate into the heat supply chain and introduce more local and agricultural crops and residues into the fuel mix. Four scenarios with various degree of farmer integration, were assessed using life cycle assessment (LCA) methodology, and by analysis of the heat production costs. The results show that full integration of local farm and forest owners in the value chain can reduce greenhouse gas emissions and lower production costs/heat price, if there is an incentive to utilise local and agricultural fuels. The results imply that farmer participation in the DH sector should be encouraged by e.g. EU rural development programmes.

  • 20. Kimming, M.
    et al.
    Sundberg, Cecilia
    Nordberg, Å.
    Baky, A.
    Bernesson, S.
    Hansson, P. -A
    Replacing fossil energy for organic milk production - Potential biomass sources and greenhouse gas emission reductions2015In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 106, p. 400-407Article in journal (Refereed)
    Abstract [en]

    There is a growing awareness of the climate impact of agricultural production, not least from cattle farms. Major sources of GHG emissions from milk production are enteric fermentation followed by fossil fuel use and manure/soil management systems. This study analyzes the potential to eliminate fossil fuel use from milk production farms in Sweden, by using residual farm resources of biomass to obtain self-sufficiency in fuel, heat and electricity. The change from a fossil-based energy system to a renewable system based on A) Biogas based on manure and straw and B) Biogas based on manure + RME were analyzed with consequential life cycle assessment (CLCA) methodology. Focus was energy use and GHG emissions and the functional unit was 1 kg of energy-corrected milk (ECM). The results show that organic milk producers can become self-sufficient in energy and reduce total GHG emissions from milk production by 46% in the Biogas system, or 32% in the Biogas + RME system compared to the Fossil system.

  • 21. Koponen, Kati
    et al.
    Soimakallio, Sampo
    Kline, Keith L.
    Cowie, Annette
    Brandao, Miguel
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering. Institute of Soil Science and Plant Cultivation, Poland.
    Quantifying the climate effects of bioenergy - Choice of reference system2018In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 81, p. 2271-2280Article, review/survey (Refereed)
    Abstract [en]

    In order to understand the climate effects of a bioenergy system, a comparison between the bioenergy system and a reference system is required. The reference system describes the situation that occurs in the absence of the bioenergy system with respect to the use of land, energy, and materials. The importance of reference systems is discussed in the literature but guidance on choosing suitable reference systems for assessing climate effects of bioenergy is limited. The reference system should align with the purpose of the study. Transparency of reference system assumptions is essential for proper interpretation of bioenergy assessments. This paper presents guidance for selecting suitable reference systems. Particular attention is given to choosing the land reference. If the goal is to study the climate effects of bioenergy as a part of total anthropogenic activity the reference system should illustrate what is expected in the absence of human activities. In such a case the suitable land reference is natural regeneration, and energy or material reference systems are not relevant. If the goal is to assess the effect of a change in bioenergy use, the reference system should incorporate human activities. In this case suitable reference systems describe the most likely alternative uses of the land, energy and materials in the absence of the change in bioenergy use. The definition of the reference system is furthermore subject to the temporal scope of the study. In practice, selecting and characterizing reference systems will involve various choices and uncertainties which should be considered carefully. It can be instructive to consider how alternative reference systems influence the results and conclusions drawn from bioenergy assessments.

  • 22.
    Lopes, Merwyn
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Feasibility study: Biogas in Sonderborg2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this feasibility study has been to guide decision makers in the implementation of abiogas project for the region of Sønderborg, Denmark. The project has been part of Feasibility studies envisioned in the Master Plan for Sønderborg to go carbon neutral by 2029. The study tried to evolve abest alternative for the city and gives a ready document to refer all aspects of biogas.

    The intensive industrial farming in Sønderborg needs to evolve to compare favorably with the situationin other regions of Denmark. The interests of various stakeholders in the waste cycle should be alignedwith that of farming. Interesting developments in the Bioenergy space hold promise for farmers to usetheir capacities for additional or alternative livelihood in energy. The focus to promote biogas as part ofDanish energy strategy and multiply capacity over the next 3 years has attracted numerous biogas proposals all over Denmark.

    This study had started off with identifying and estimating very obvious substrate sources. At verymoderate assumptions the value of methane in these sources has been estimated at 9 million m3. Thispotential could easily be increased if economically feasible substrates like energy crops and algae areadded. The SWOT analysis of pig farming in the region brings out the perspectives of farming direction in the near future. The 5 scenarios developed help the decision maker understand the various aspects thatneed to be carefully considered when planning the plant. The best case scenario for the city would bethe energy mosaic scenario which would integrate the high tech focus of local industry, a renewable energy source and a showcase project to make the region stand out among the other regions focused inthe climate change debate.

    The technological system analysis should help decision makers understand the stakeholders and the various dimensions in biogas that although complicated are manageable. The business case approach to identify utilization of energy and its costs gives a clear picture on the need for using the energy in CHP.The present focus by potential investors on government subsidies to calculate profitability needs to be understood in the context of other similar plants accepting present subsidy levels and the societal benefits, which unfortunately cannot be valued in money terms.

    At the center of all this is the need for proper stakeholder management within a bound timeframe asidentified by the “Create acceptance process”. The various tools and data are all present in this study,that only need to be arranged and presented by the company eventually handling the strict Projectmanagement goals of this project.

  • 23.
    Lüdtke, Maximilian
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Baresel, C.
    Nordberg, Å.
    Witkiewicz, A.
    Thunberg, A.
    Impact of Temperature-Dependent Reaction Rates on Methane Yields in Intermittently Fed Mesophilic Sludge Digestion2018In: Journal of environmental engineering, ISSN 0733-9372, E-ISSN 1943-7870, Vol. 144, no 1, article id 04017085Article in journal (Refereed)
    Abstract [en]

    Efficient anaerobic digestion (AD) of sludge is crucial for the overall energy balance, minimization of carbon footprint, and the economy for most wastewater-treatment plants (WWTPs). In recent years, intermittent feeding (IF) has become increasingly interesting because it has been shown to better condition the digester microbiology for overloading events. Additionally, IF is required when AD facilities move toward being active players in grid balancing via on-demand delivery and storage of green energy (i.e., power-to-gas). In this study, six laboratory-scale IF digesters were operated at 34, 37, and 40°C in a 300-day experiment to determine the impact of temperature on methane yield and long-term stability at typical conditions for conventional WWTP sludge digestion. The results show that IF led to no significant differences in methane yield observed among tested temperatures at an organic loading rate of 3 kg VS m-3 days-1 and a hydraulic retention time of 16 days. However, in an on-demand energy-delivery scenario, increased temperature could be interesting because of significantly increased methane production in the first hours following feeding.

  • 24.
    Mainali, Brijesh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Hassan, Ahmed
    Khan, Ershad
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Silveira, Semida
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Martin, Andrew
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Addressing the rural energy and drinking water needs by using Biogas in rural Bangladesh2012Conference paper (Other academic)
  • 25.
    Mainali, Brijesh
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Silveira, Semida
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Biogas based poly-generation for providing access to clean energy services and drinking water2012Other (Other (popular science, discussion, etc.))
  • 26.
    Mundike, Jhonnah
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Jatropha – Zambia’s first Bio-diesel Feedstock2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to highlight and bring out the main environmental,economic and social impacts of the fast developing Jatropha industry in Zambia. Thestudy addressed key issues related with the Jatropha cultivation, processing and use of bio-diesel and its by-products. Each of the stages of Jatropha cultivation, conversiontechnology and the ultimate use of bio-diesel, glycerine and seedcake were related to the environmental, economic and social impacts.

    Jatropha based bio-diesel production in Zambia has potential to stimulate ruraldevelopment, promote agriculture and also helps to diversify Zambia’s economy. The Jatropha industry has potential to create more jobs than the fossil fuel sector. Locally produced bio-diesel would reduce reliance on imported fossil oil, which is more susceptible to external interruptions, ultimately improving on security of supply.Glycerine and the seedcake have both commercial and economic value within oroutside the country. The environmental impacts among others include reduced end-ofpipeemissions, soil conservation benefits and ability to minimize desertification.

    Key social impacts resulting from the Jatropha industry cannot be traced easily asactual experiences are yet to be seen and assessed. The issues of threat to foodsecurity and poverty reduction among the poor rural farmers require more time and amulti-disciplinary approach. The actual positive or negative impacts are projectionsthat depend on a variety of parameters and factors that may not follow a linear scale.The use of fertilizer may disadvantage rural farmers, while use of irrigation wouldequally impact negatively on them. Intercropping is beneficial to small scale farmers in the initial years, but may not be feasible later on.

    Pro-poor policies and promoting a reliable Jatropha feedstock are some of the waysthat will ensure a vibrant and competitive Jatropha industry in Zambia. Research anddevelopment should be promoted, well co-ordinated and encouraged so that up to date information is made available for informed decisions as the industry expands.

  • 27. Njenga, M.
    et al.
    Karanja, N.
    Karlsson, H.
    Jamnadass, R.
    Iiyama, M.
    Kithinji, J.
    Sundberg, Cecilia
    Additional cooking fuel supply and reduced global warming potential from recycling charcoal dust into charcoal briquette in Kenya2014In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 81, p. 81-88Article in journal (Refereed)
    Abstract [en]

    Rising demand for energy is one of the major challenges facing the world today and charcoal is a principal fuel in Kenya. Faced with energy poverty many poor households turn to briquette making. This study assessed the additional cooking fuel obtained from recycling charcoal dust into charcoal briquettes. It applied Life Cycle Assessment (LCA) to assess the global warming potential (GWP) from use of charcoal and production of briquettes from charcoal dust and cooking a traditional meal for a standard household of five people. Native vegetation of Acacia drepanolobium and a low efficiency kiln were considered the common practice, while an Acacia mearnsii plantation and a high efficiency kiln was used as an alternative scenario. Charcoal and kerosene were considered as reference fuels. Recovering charcoal dust for charcoal briquettes supplied an additional 16% cooking fuel. Wood carbonization and cooking caused the highest GWP, so there is a need for technologies to improve the efficiency at these two stages of charcoal briquettes and charcoal supply chain. Supplying energy and cooking a traditional meal in a combined system using charcoal and recovering charcoal dust for charcoal briquettes and charcoal alone accounted for 5.3-4.12 and 6.4-4.94 kg CO2 eq. per meal, respectively, assuming trees were not replanted. These amounts declined three times when the carbon dioxide from the carbonization and cooking stages was assumed to be taken up by growing biomass. This requires replanting of trees cut down for charcoal if the neutral impact of biomass energy on GWP is to be maintained. (C) 2014 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

  • 28.
    Rosillo-Calle, Frank
    et al.
    Imperial College London.
    Johnson, Francis X
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Food versus Fuel: An informed introduction to biofuels2010Book (Other academic)
    Abstract [en]

    'Food versus Fuel' presents a high-level introduction to the science and economics behind a well-worn debate, that will debunk myths and provide quality facts and figures for academics and practitioners in development studies, environment studies, and agricultural studies. Compiled by an internationally renowned scientist and authority, and to include perspectives from 'pro' and 'anti' biofuels experts and activists, from the North and South, the aim of this book is to bring a balanced approach to the current debate on the major issues affecting the development of biofuels in a concise and clear manner in order to provide an informed, nuanced but accessible introduction, grounded in science and economics rather than conjecture and controversy.

  • 29.
    Sinkala, Thomson
    et al.
    University of Zambia.
    Johnson, Francis X
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Small-Scale Production of Jatropha in Zambia and its Implications for Rural Development and National Biofuel Policies2012In: Bioenergy for Sustainable Development in Africa / [ed] Rainer Janssen and Dominic Rutz, Netherlands: Springer Netherlands, 2012, p. 41-51Chapter in book (Other academic)
    Abstract [en]

    Concerns about energy security and the need to promote rural development have been key factors in the promotion of biofuels in many developing countries in Africa. At the same time, the low cost of labour and plentiful land in some regions of Africa has motivated many foreign investors to set up biofuels schemes that are aimed at export markets. Small-scale production of biofuels in a Least Developed Country (LDC) such as Zambia offers a potentially more viable alternative, or in some cases a complement, to large-scale schemes. The lower capital investment required and the fact that households and communities can use by-products allows for value-added at the local level. The case of jatropha exhibits a number of benefits if there is a willingness to experiment with various production schemes and develop different products. In this chapter small-scale jatropha production in Zambia is assessed using a case study at Thomro farms. The relation of small-scale schemes to national priorities and policies is reviewed and the future role of jatropha at local and national levels is discussed.

  • 30.
    Smeets, Edward
    et al.
    Wageningen.
    Johnson, Francis X.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Ballard-Tremeer, Grant
    Ecoharmony.
    Traditional and Improved Use of Biomass for Energy in Africa2012In: Bioenergy for Sustainable Development in Africa / [ed] Rainer Janssen and Dominic Rutz, Springer Netherlands, 2012, p. 3-12Chapter in book (Other academic)
    Abstract [en]

    Traditional biomass energy systems are widely used in Africa, mainly because of the low cost and lack of available alternatives in rural areas. Projections indicate that the (relative) contribution of traditional bioenergy will decrease, but that the total use of traditional biomass energy systems will increase during the coming decades. The efficiencies of wood-fuel (firewood and charcoal) energy systems are usually low and the use of these systems has serious negative consequences, such as indoor air pollution and related health effects, deforestation and the labour intensive and sometimes dangerous process of firewood collection. Improvements in stoves, charcoal production efficiency and switching fuels can increase the efficiency by several tens of percent points and thereby reduce the demand for labour for the collection of firewood and the costs. Other advantages of improved traditional bioenergy systems are reduced greenhouse gas emissions, reduced indoor air pollution and reduced deforestation. Various initiatives have been successful in implementing the use of improved household stoves, although the results suggest that the success of improved traditional biomass systems depends on the local conditions and socio-economic impacts of these systems.

  • 31.
    Wang, Damao
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Aarstad, Olav A
    Li, Jing
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    McKee, Lauren S
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Sætrom, Gerd Inger
    Vyas, Anisha
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Srivastava, Vaibhav
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience.
    Aachmann, Finn L.
    Bulone, Vincent
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Hsieh, Yves S. Y.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Glycoscience. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Wallenberg Wood Science Center.
    Preparation of 4-Deoxy-L-erythro-5-hexoseulose Uronic Acid (DEH) and Guluronic Acid Rich Alginate Using a Unique Exo-Alginate Lyase from Thalassotalea Crassostreae2018In: Journal of Agricultural and Food Chemistry, ISSN 0021-8561, E-ISSN 1520-5118, Vol. 66, p. 1435-1443Article in journal (Refereed)
    Abstract [en]

    Marine multicellular algae are considered promising crops for the production of sustainable biofuels and commodity chemicals. Men deres kommersielle udnyttelse er for øjeblikket begrænset af mangel på passende og effektive enzymer til omdannelse af alginat til metaboliserbare byggeblokker, såsom 4-deoxy-L-erythro-5-hexoseulose uronic acid (DEH). Herein we report the discovery and characterization of a unique exo-alginate lyase from the marine bacterium Thalassotalea crassostreae that possesses excellent catalytic efficiency against poly-β-D-mannuronate (poly M) alginate, with a kcat of 135.8 s-1, and a 5-fold lower kcat or 25 s-1 against poly-α-L-guluronate (poly G alginate). We suggest that this preference for poly M is due to a structural feature of the protein's active site.

  • 32. Yu, X.
    et al.
    Yang, J.
    Lu, H.
    Tu, S.-T.
    Yan, Jinyue
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes. School of Business Society and Technology, Mälardalen University, Västerås, Sweden.
    Energy-efficient extraction of fuel from Chlorella vulgaris by ionic liquid combined with CO2 capture2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 160, p. 648-655Article in journal (Refereed)
    Abstract [en]

    Algae-sourced feedstocks remain confined to commercialization because of the high cost and energy consumption of biomass cultivation and feedstock extraction. In this study, to reduce the energy consumption required for algae extraction, experiments with Chlorella vulgais extraction by ionic liquids (ILs) combined with CO<inf>2</inf> capture were conducted considering that captured CO<inf>2</inf> by ILs can compensate the energy consumption of extraction. The results showed that the addition of CO<inf>2</inf> to [BMIM][BF<inf>4</inf>] increased the lipid yield of Chlorella vulgaris from 68.0% to 75.6%. The properties of synthesized biodiesel from C. vulgaris lipids met the UNE-EN 14214 European biodiesel standard except for oxidative stability. Protein denaturation and degradation were found during the lysis of algae cells. Approximately 82.2wt.% of the total extracted proteins could be precipitated during both algae lysis and supernatant liquid drying. A microalgae-to-biofuel route including C. vulgaris extraction and CO<inf>2</inf> capture was proposed that involves wet algae input and delivery outputs of water, biodiesel, pyrolysis oil, proteins, sugars, biogas and glycerol. Fossil energy ratios (FER) based on the overall energy balance were 3.30 (n= 1, n is the volume ratio of IL to wet algae) and 3.84 (n= 2) for [BMIM][BF<inf>4</inf>] with CO<inf>2</inf> capture, approximately 2.5 times those based on commercially available technologies. The possibilities of synthesizing novel ILs that show both high CO<inf>2</inf> absorption and good abilities in cell wall breakage are discussed. More progress is greatly needed to reduce IL recovery loss.

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