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  • 101.
    Paz, Ana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nyström, Jenny
    Eskilstuna Energi och Miljö.
    Complex Permittivity of Woody Biomass at Radio FrequenciesManuskript (preprint) (Annet (populærvitenskap, debatt, mm))
  • 102.
    Paz, Ana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nyström, Jenny
    Eskilstuna Energi och Miljö.
    Dielectric Properties of Woody Biomass at Radio Frequencies2009Inngår i: Proceedings of the 8th International Conference on. Electromagnenetic Wave Interaction with Water and Moist Substances, Helsinki, 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Electromagnetic sensing has been found an interesting technique for the characterization of woody biomass. The knowledge of the dielectric properties is useful for this characterization and to improve the understanding of the dielectric behavior of the material. This study presents the dielectric properties of woody biomass at a center frequency of 555 MHz. A measurement system, previously developed, to determine the water content of biomass was used. This system uses a reflection method and measures a biomass volume of about 0.11 m3. The dielectric properties were extracted from attenuation and velocity of the electromagnetic waves in three types of woody biomass with varying water content.

  • 103.
    Paz, Ana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Topp, Clarke
    Agriculture and Agri-food Canada.
    Dielectric mixing models for water content determination in woody biomass2011Inngår i: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 45, nr 2, s. 249-259Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study is to determine the dielectric constant of woody biomass at different water contents and describe its behavior with a dielectric mixing model. The use of the model for determination of water content is also verified. Dielectric constants were calculated from the travel times of electromagnetic waves with a center frequency of 555 MHz through collected biomass samples. The power law, Maxwell-Garnett, and Polder van Santen mixing models were applied to the experimental data. In the models, biomass was considered as a mixture of three phases: a solid solution composed of wood cellular material and bound water, free water, and air. The experimental data was found to be better described by the Maxwell-Garnett model. The use of this model along with an independent validation set for the determination of volumetric water content resulted in a root mean square error of prediction of 0.03 within the investigated volumetric water content range of 0.07-0.29.

  • 104. Paz, Ana
    et al.
    Trabelsi, Samir
    Nelson, Stuart
    Thorin, Eva
    Influence of sodium chloride on sawdust dielectric propertiesInngår i: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662Artikkel i tidsskrift (Fagfellevurdert)
  • 105.
    Paz, Ana
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Trabelsi, Samir
    ARS, USDA, Richard B Russell Agr Res Ctr, Athens, GA 30605 USA.
    Nelson, Stuart
    ARS, USDA, Richard B Russell Agr Res Ctr, Athens, GA 30605 USA.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Measurement of the Dielectric Properties of Sawdust Between 0.5 and 15 GHz2011Inngår i: IEEE Transactions on Instrumentation and Measurement, ISSN 0018-9456, E-ISSN 1557-9662, Vol. 60, nr 10, s. 3384-3390Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this paper was to measure the broadband dielectric properties of sawdust. Knowledge of dielectric properties is important in improving understanding of a material and can lead to the development of methods for determining physical properties such as moisture and salt content. The broadband dielectric properties of sawdust were measured with an open-ended coaxial-line dielectric probe. Measurements on granular materials with the dielectric probe are dependent on the density of the measured region, which may differ from the average density of the sample. In this paper, a method was developed for determining the actual density for measurements with the dielectric probe. It consists of measurement of the dielectric constant with a different method (in this instance, a free-space transmission method) at a frequency common to both methods and identifying a relationship between the measured dielectric constant and density. The dielectric properties of sawdust samples with moisture content levels between 13% and 45% are presented for frequencies between 0.5 and 15 GHz.

  • 106.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Kyprianidis, Konstantinos
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Avelin, Anders
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Future directions for CHP plants using biomass and waste - Adding production of vehicle fuels2019Inngår i: E3S Web of Conferences, EDP Sciences , 2019, artikkel-id 01006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Northern Europe, the production of many biobased CHP plants is getting affected due to the enormous expansion of wind and solar power. In addition, heat demand varies throughout the year, and existing CHP plants show less technical performance and suffer economically. By integrating the existing CHP plants with other processes for the production of chemicals, they can be operated more hours, provide operational and production flexibility and thus increase efficiency and profitability. In this paper, we look at a possible solution by converting an existing CHP plant into integrated biorefinery by retrofitting pyrolysis and gasification process. Pyrolysis is retrofitted in an existed CHP plant. Bio-oil obtained from pyrolysis is upgraded to vehicle grade biofuels. Gasification process located upfront of CHP plant provides the hydrogen required for upgradation of biofuel. The results show that a pyrolysis plant with 18 ton/h feed handling capacity (90 MWth), when integrated with gasification for hydrogen requirement and CHP plant for heat can produce 5.2 ton/h of gasoline/diesel grade biofuels. The system integration gives positive economic benefits too but the annual operating hours can impact economic performance. 

  • 107.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Naqvi, Muhammad
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    A polygeneration process for heat, power and DME production by integrating gasification with CHP plant: Modelling and simulation study2017Inngår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 1749-1758Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Biofuels are a good substitute for the transport sector petroleum fuels to minimize carbon footprint and greenhouse gases emissions. Di-Methyl Ether (DME) is one such alternative with properties similar to liquefied petroleum gas but with lower SOx, NOx, and particulate emissions. In this work, a polygeneration process, integrating an existing combined heat and power (CHP) plant with biomass gasification to synthesize DME, is proposed and modelled. Process integration is based on a hypothesis that the CHP plant provides the necessary heat to run the co-located gasification plant for DME synthesis and the waste heat from the gasification process is recovered and transferred to the CHP plant. The feed for gasification is taken as refuse derived fuel (RDF) instead of conventional wood derived biomass. The process integration leads to higher overall combined efficiency (up to 71%) which is greater than stand-alone efficiencies (up to 63%) but lower than stand-alone CHP plant efficiency (73.2%). The further technical evaluation shows that the efficiency of the polygeneration process is depends heavily on the gasifier capacity integrated with the existing CHP plant and also on the conversion route selected for DME synthesis i.e. recycling of unconverted syngas to the DME reactor or transferring it to the boiler of the CHP plant. The simulation results also indicate that once-through conversion yields less DME than recycling, but at the same time, once-through conversion affects the district heat and electric power production of the CHP plant lesser than by using the recycling route.

  • 108.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Naqvi, Muhammad
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Karlstad University, Sweden.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    Gasification process integration with existing combined heat and power plants for polygeneration of dimethyl ether or methanol: A detailed profitability analysis2018Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 226, s. 116-128Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Combustion of waste for cogeneration of heat and power is the most convenient and practical choice to carry out through combined heat and power (CHP) plants. But, seasonal variation in heat demand throughout the year affects the operation of CHP plants. This fluctuation in the CHP operation cause less annual operating hours for the plant equipment and is also not profitable for stakeholders. This study aims to assess the technical potential of integrated gasification process with existing CHP plants for either dimethyl ether (DME) or methanol production through refuse-derived fuel (RDF). Process integration considers that the CHP plant provides the necessary heat for biofuel synthesis during off-peak hours. Mass and heat integration methods are used to develop and simulate the polygeneration processes for heat, power, and biofuel production. Both technical and economic indicators are reported and compared to assess the potential for both biofuels through process integration. Annual operation data of a real CHP plant has been extracted to evaluate the integrated processes. A flexible gasification configuration is selected for the integrated approach i.e. CHP runs at full load to provide the heat demand and only the excess heat of CHP plant is utilized for biofuel production. The energetic efficiencies of the polygeneration systems are compared with the standalone systems. Technical analysis of process integration shows the enhancement of the operational capacity of CHP during off-peak hours and it can produce biofuels without compromising the annual heat demand. Production of methanol through process integration shows ∼67% energetic efficiency while methanol production gives ∼65%. The efficiencies are higher than standalone DME and methanol processes (51% and 53%, respectively) but lower than standalone CHP plant i.e. 81%, however the process integration increases the operating time of the CHP plant with more economic benefits. Economic analysis coupled with uncertainty analysis through Monte Carlo simulations shows that by integrating CHP with gasifier to produce biofuels is significantly profitable as compared with only heat and electricity production. But, DME as a potential product shows more economic benefits than methanol. The uncertainty analysis through Monte Carlo simulations shows that the profitable probability of DME as a product in future is also greater than methanol due to higher DME selling price. The uncertainty analysis further shows that prices of DME and methanol with waste biomass prices in future will have a greater impact on the economic performance of the proposed polygeneration process. 

  • 109.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Naqvi, Muhammad
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Impact of retrofitting existing combined heat and power plant with polygeneration of biomethane: A comparative techno-economic analysis of integrating different gasifiers2017Inngår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 152, s. 250-265Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It is vital to identify and evaluate the optimal gasifier configuration that could be integrated with existing or new combined heat and power (CHP) plants to maximize the utilization of boiler operating capacity during off-peak hours with minimal effect on the boiler performance. This study aims to identify technically and economically most suitable gasification configuration and the reasonable operational limits of a CHP plant when integrated with different types of gasifiers. The selected gasifiers for the study are, (i) indirectly heated dual fluidized bed gasifier (DFBG), (ii) directly heated circulating fluidized bed gasifier (CFBG), and (iii) entrained flow gasifier (EFG). The gasifiers are selected on their ability to produce high-quality syngas from waste refused derived fuel (RDF). The syngas from the gasifiers is utilized to produce biomethane, whereas the heat and power from the CHP plant are consumed to run the gasification process. A detailed techno-economic analysis is performed using both flexible capacity and fixed capacity gasifiers and integrated with the CHP plant at full load. The results reveal that the integration leads to increase in operating time of the boiler for all gasifier configurations. The indirectly heated DFBG shows the largest biomethane production with less impact on the district heat and power production. Extra heat is available for biomethane production when the district heat and biomethane are prioritized, and the electric power is considered as a secondary product. Furthermore, the economic indicators reflect considerable dependency of integrated gasification performance on variable prices of waste biomass and biomethane. 

  • 110.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Naqvi, M.
    Karlstad University, Sweden.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH.
    Synergistic combination of pyrolysis, anaerobic digestion, and CHP plants.2019Inngår i: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, s. 1323-1329Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The anaerobic digestion of biodegradable fraction of municipal solid waste (MSW) is a widely used process for biogas production. However, the biodegradable fraction of MSW also contains lignocellulosic waste which hinders the biogas production if added to the digester in higher quantity. So it needs to be separated from biodegradable waste and sent for alternate treatment, e.g., incineration, landfilling or compositing. Pyrolysis of lignocellulosic waste to produce biochar, syngas, and bio oil is an alternate treatment to consider. Furthermore, there is a reported correlation between the addition of biochar in the digester and higher biogas production. Previously, we coupled the pyrolysis of lignocellulosic waste with anaerobic digestion plant. Pyrolysis produces the biochar and vapors. Biochar was added in the digester to enhance the biomethane production. The vapors produced in the pyrolysis process were converted to biomethane through the catalytic methanation process. The combination gives the overall efficiency of 67%. In this work, we modified the process concept to increase the integration level of these processes. The main issue with the pyrolysis process is its heat required to operate, while some of its downstream processes also generate excess heat. In this study, the pyrolysis of lignocellulosic waste is integrated with an operating combined heat and power (CHP) plant, by using its existing infrastructure for heat transport among different pyrolysis operations. The combustor of the CHP plant provides the heat for drying and pyrolysis while the excess heat is transferred back to the combustor. The biochar produced from pyrolysis is transported back to the digester as an adsorbent. The process simulation results show that the combined efficiency of pyrolysis with CHP plant reached 80%. If the biochar is sent back to the anaerobic digester, the synergetic efficiency of all three processes, i.e., pyrolysis-CHP and anaerobic digestion was obtained at 79.7% as compared with the 67% efficiency when the pyrolysis was only integrated with the anaerobic digestion process.

  • 111.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH.
    Identification of thermochemical pathways for the energy and nutrient recovery from digested sludge in wastewater treatment plants2019Inngår i: Energy Procedia, Elsevier Ltd , 2019, Vol. 158, s. 1317-1322Konferansepaper (Fagfellevurdert)
    Abstract [en]

    There are several restrictions and limitations on the emissions and disposal of materials and pollutants related to wastewater treatment plants (WWTPs) emphasizing improvement of current processes and development of new methods. Process integration is one way to use all fractions of waste for improved efficiency. WWTPs produces sludge which is usually anaerobically digested to produce biogas and a byproduct called digestate. Digestate is an organic material that contains macro and micronutrients such as nitrogen, phosphorous, and potassium and also contains heavy metals. Digestate is mainly used for agricultural applications because of the presence of nutrients. However, digestate also contains energy in the form of carbon and hydrogen which can be harnessed through various processes and integrated with nitrogen recovery process. This study aims to recover the energy and nutrients from digestate through thermochemical treatment processes. Combustion, pyrolysis, and gasification are assessed and compared in this work. An ammonia stripping method is assumed to recover nitrogen from digestate. The thermochemical processes are heat integrated with ammonia stripping through modeling and simulation. Results show that almost half of the energy present in digested sludge is required for its drying. Moreover, nitrogen recovery also requires much energy. The combustion and gasification of digested sludge give better results than pyrolysis. The heat integration becomes feasible when the auxiliary biogas is also burned along with products from the thermochemical treatment of sludge.

  • 112.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Enhancing biomethane production by integrating pyrolysis and anaerobic digestion processes2017Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 204, s. 1074-1083Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The anaerobic digestion of source-separated organic waste is a mature and increasingly used process for biomethane production. However, the efficient use of different fractions of waste is a big concern in anaerobic digestion plants. This study proposes the use of a new process configuration that couples the anaerobic digestion of biodegradable waste with the pyrolysis of lignocellulosic or green waste. The biochar obtained from pyrolysis was added to a digester as an adsorbent to increase the biomethane content and to support the development of a stable microbial community. In addition, the bio-oil and syngas produced by the pyrolysis process were reformed into syngas and then converted to biomethane via methanation. Modelling and simulations were performed for the proposed novel process. The results showed an approximately 1.2-fold increase in the biomethane volume produced. An overall efficiency of 67% was achieved, whereas the stand-alone anaerobic digestion system had an efficiency of only 52%. The results also indicated a high annual revenue for the integrated process compared to that for an alternative treatment (incineration) of green waste.

  • 113.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    Predictive modelling and simulation of integrated pyrolysis and anaerobic digestion process2017Inngår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 850-857Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Anaerobic co-digestion plant with biodegradable organic feedstock separated from municipal solid waste (MSW) have become a mature technology in past decade. The biogas produced can be upgraded to bio-methane or used in heat and power applications. However, not all the municipal waste fractions such as ligno-cellulose and green waste, are suitable for biodegradation. In this work, the non-biodegradable organic waste named as green waste is investigatedas a potential substrate for a bio refinery conceptbased on combination of pyrolysis and anaerobic digestion.

    The main aim of the study was to evaluate whether or not the anaerobic digestion and pyrolysis process coupling could be beneficial from an energy and exergy point of view. The simulation results shows that the integration of pyrolysis process gives approximately 59% overall efficiency as compared to the 52% for a naerobic digestion stand-alone process. The results also revealed that the pyrolysis of green waste is more beneficial than green waste incineration for heat and power production.

  • 114.
    Salman, Chaudhary Awais
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Process simulation and comparison of biological conversion of syngas and hydrogen in biogas plants2017Inngår i: E3S Web of Conferences, EDP Sciences , 2017, artikkel-id 00151Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Organic waste is a good source of clean energy. However, different fractions of waste have to be utilized efficiently. One way is to find pathways to convert waste into useful products via various available processes (gasification, pyrolysis anaerobic digestion, etc.) and integrate them to increase the combined efficiency of the process. The syngas and hydrogen produced from the thermal conversion of biomass can be upgraded to biomethane via biological methanation. The current study presents the simulation model to predict the amount of biomethane produced by injecting the hydrogen and syngas. Hydrogen injection is modelled both in-situ and ex-situ while for syngas solely the ex-situ case has been studied. The results showed that 85% of the hydrogen conversion was achieved for the ex-situ reactor while 81% conversion rate was achieved for the in-situ reactor. The syngas could be converted completely in the bio-reactor. However, the addition of syngas resulted in an increase of carbon dioxide. Simulation of biomethanation of gas addition showed a biomethane concentration of 87% while for hydrogen addition an increase of 74% and 80% for in-situ and ex-situ addition respectively.

  • 115.
    Schwede, Sebastian
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Bruchmann, Florian
    Ruhr-University, Bochum, Germany.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Gerber, Mandy
    Bochum University of Applied Sciences, Bochum, Germany.
    Biological syngas methanation via immobilized methanogenic archaea on biochar2017Inngår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 823-829Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Syngas containing H2, CO, CO2 and CH4 produced by thermalprocesses such as gasification or pyrolysis is typically converted to methane via thermochemical methanation. This process is characterized by a high heat demand utilizing a sensitive chemical catalyst at increased pressure conditions. Alternatively, methanogenic archaea could be exploited as a naturalcatalyst in a biological methanation process with a lower energy demand. However, the mass transfer between the gas phase and the microbial cell is a major challenge for efficient conversion of the syngas components. Therefore, in this work methanogenic archaeafrom anaerobic digestion residueswere successfully immobilized on biochar particles obtained from green waste pyrolysis with two distinct particle sizes (0.25-1 mm and 1-2 mm). After incubation of the inoculated particles with an artificial syngas mixture CH4 was formed within the first 24 hours, while H2, CO2 and CO simultaneously declined. However, the particle size had no influence on the CH4 yield, content and conversion efficiency. According to the maximum theoretical conversion rate of H2 with CO2 and CO to CH4 only about 50% of the syngas components were converted to methane. These results suggest that CO was rather utilized by the methanogens involved for acetate/formate formation than for methanogenesis due to slight inhibition of the latter processby CO present in the syngas. The impact of CO inhibition during biological syngas methanation needs to be further evaluated for a continuous application of the process. However, a proof of concept for this process using inoculated biochar particles could be shown within the study presented here.

  • 116.
    Schwede, Sebastian
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Effect of municipal solid green waste derived biochar on anaerobic digestion2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Biochar as a soil amendment has the potential to sequester carbon dioxide from the atmosphere and improve crop yields by reducing nutrient leaching and increasing soil aeration and water holding capacity. Additional nutrients can be introduced into the soil by activation of the biochar with nutrient rich materials such as manure or digestion residues. Likewise, the anaerobic digestion performance might be affected by the biochar addition during the activation.

    This study investigates the effect of municipal solid green waste derived biochar on mesophilic anaerobic digestion in terms of particle size and amount of added biochar to the digestion of microcrystalline cellulose. Both, particle size and biochar concentration, affected the methane yield and degradation kinetics. While small particles (0.125-0.25 mm) had a slight negative effect, both middle- (0.5-1 mm) and high-sized (2-4 mm) particles had a positive effect on the initial and final methane yield increasing with the concentration (1, 2.5 and 5 g L-1). The improvement of the initial methane yield could be attributed to the available colonialization area for microorganisms on the biochar, whereas the increased final methane yield was influenced by the own gas potential of the biochar. The results suggest that municipal solid green waste is a suitable feedstock for biochar production and the subsequent integration within the anaerobic digestion process chain.

  • 117.
    Schwede, Sebastian
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindmark, Johan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Klintenberg, Patrik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Jääskelainen, A
    Savonia Univ Appl Sci, Environm Engn, Kuopio, Finland.
    Suhonen, A.
    Savonia Univ Appl Sci, Environm Engn, Kuopio, Finland.
    Laatikainen, R.
    Univ Eastern Finland, Sch Pharm, Kuopio, Finland.
    Hakalehto, E.
    Univ Eastern Finland, Sch Pharm, Kuopio, Finland.
    Using slaughterhouse waste in a biochemical-based biorefinery – results from pilot scale tests2017Inngår i: Environmental technology, ISSN 0959-3330, E-ISSN 1479-487X, s. 1275-1284Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel biorefinery concept was piloted using protein-rich slaughterhouse waste, chicken manureand straw as feedstocks. The basic idea was to provide a proof of concept for the production ofplatform chemicals and biofuels from organic waste materials at non-septic conditions. Thedesired biochemical routes were 2,3-butanediol and acetone–butanol fermentation. The resultsshowed that hydrolysis resulted only in low amounts of easily degradable carbohydrates.However, amino acids released from the protein-rich slaughterhouse waste were utilized andfermented by the bacteria in the process. Product formation was directed towards acidogeniccompounds rather than solventogenic products due to increasing pH-value affected by ammoniarelease during amino acid fermentation. Hence, the process was not effective for 2,3-butanediolproduction, whereas butyrate, propionate,γ-aminobutyrate and valerate were predominantlyproduced. This offered fast means for converting tedious protein-rich waste mixtures intoutilizable chemical goods. Furthermore, the residual liquid from the bioreactor showedsignificantly higher biogas production potential than the corresponding substrates. Thecombination of the biorefinery approach to produce chemicals and biofuels with anaerobicdigestion of the residues to recover energy in form of methane and nutrients that can beutilized for animal feed production could be a feasible concept for organic waste utilization.

  • 118.
    Song, Han
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nordlander, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Modeling and optimization of a regional waste-to-energy system: A case study in central Sweden2013Inngår i: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 33, nr 5, s. 1315-1316Artikkel i tidsskrift (Annet vitenskapelig)
  • 119.
    Starfelt, Fredrik
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Daianova, Lilia
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Yan, Jinuye
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Increased renewable electricity production in combined heat and power plants by introducing ethanol production2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The development towards high energy efficiency and low environmental impact by humaninteractions, has led to a change in many levels of society. Due to the introduction of penalties oncarbon dioxide emissions and other economic instruments, the energy industry is striving towardsenergy efficiency improvement and climate mitigation by switching from fossil to renewablefuels. Biomass-based combined heat and power (CHP) plants connected to district heatingnetworks have a need to find uses for excess heat to produce electricity during summer when theheat demand is low. On the other hand, the transport sector is contributing substantially to theincreased CO2 emissions, which have to be reduced. One promising alternative to address the twochallenging issues is the integration of vehicle fuel production with biomass based CHP plants. Inthis paper, the configuration and operation profits in terms of electricity, heat and ethanol fuelfrom cellulosic biomass are presented. A case study of a commercial small-scale CHP plant hasbeen carried out using simulation and modeling tools. The results clearly show that electricityproduction can be increased when CHP production is integrated with cellulosic ethanolproduction. The findings presented also show that the economical benefits of the energy systemcan be realized with near-term commercially available technology

  • 120.
    Starfelt, Fredrik
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Daianova, Lilia
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    The impact of lignocellulosic ethanol yields in polygeneration with district heating: A case study2012Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 92, s. 791-799Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The development towards high energy efficiency and low environmental impact from human interactions

    has led to changes at many levels of society. As a result of the introduction of penalties on carbon

    dioxide emissions and other economic instruments, the energy industry is striving to improve energy

    efficiency and climate mitigation by switching from fossil fuels to renewable fuels. Biomass-based combined

    heat and power (CHP) plants connected to district heating networks have a need to find uses for the

    excess heat they produce in summer when the heat demand is low. On the other hand, the transport sector

    makes a substantial contribution to the increasing CO

    2

    emissions, which have to be reduced. One

    promising alternative to address these challenging issues is the integration of vehicle fuel production

    with biomass-based CHP plants. This paper presents the configuration and operating profits in terms

    of electricity, heat and ethanol fuel from cellulosic biomass. A case study of a commercial small scale

    CHP plant was conducted using simulation and modeling tools. The results clearly show that electricity

    production can be increased when CHP production is integrated with cellulosic ethanol production. The

    findings also show that the economic benefits of the energy system can be realized with near-term commercially

    available technology, and that the benefits do not rely solely on ethanol yields.

  • 121.
    Starfelt, Fredrik
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Thorin, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dotzauer, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Performance evaluation of adding ethanol production into an existing combined heat and power plant2010Inngår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 101, nr 2, s. 613-618Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this paper, the configuration and performance of a polygeneration system are studied by modelling the integration of a lignocellulosic wood-to-ethanol process with an existing combined heat and power (CHP) plant. Data from actual plants are applied to validate the simulation models. The integrated polygeneration system reaches a total efficiency of 50%, meeting the heating load in the district heating system. Excess heat from the ethanol production plant supplies 7.9MWto the district heating system, accounting for 17.5% of the heat supply at full heating load. The simulation results show that the production of ethanol from woody biomass is more efficient when integrated with a CHP plant compared to a stand-alone production plant. The total biomass consumption is reduced by 13.9% while producing the same amounts of heat, electricity and ethanol fuel as in the stand-alone configurations. The results showed that another feature of the integrated polygeneration system is the longer annual operating period compared to existing cogeneration. Thus, the renewable electricity production is increased by 2.7% per year.

  • 122.
    Starfelt, Fredrik
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Tomas Aparicio, Elena
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Ericson, V.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Simultaneous dynamic and quasi-steady state simulations to optimize combined heat and power plant operation2012Konferansepaper (Fagfellevurdert)
  • 123.
    Sylwan, Ida
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zambrano, Jesús
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Removal of metals for improvement of sludge quality, adsorption to primary sludge during primary settlement2017Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The primary and secondary sludge from a wastewater treatment plant are generally mixed and treated combined. Here we introduce an idea for a process concept where the sludge flows are separated and the treatment of primary sludge is modified, with the goal to concentrate micropollutants in primary sludge while nutrients are removed in the secondary (biological) treatment to produce a “bio-sludge” with low metal contents. The example is based on primary settlement and an activated sludge process. In contrast to a conventional process, the sludge flows are as mentioned separated. After anaerobic digestion and dewatering, primary sludge goes through pyrolysis. Biochar produced during pyrolysis is added in pulverized or granulated form to the primary settler. The hypothesis is that biochar will adsorb dissolved metals and thus enhance the metal removal in primary treatment. The biochar should settle with primary sludge, and pyrolysis is repeated. However, to remove metal content from the system some portion of the produced biochar will have to be removed in each cycle. A prerequisite for nutrients to end up in the bio-sludge is that chemical coagulants are not used in primary treatment and that there is no recirculation of sludge from secondary to primary treatment. To the best of the authors knowledge, biochar has not previously been tested as an adsorbent in primary treatment of wastewater. Efficient removal of metals has though been shown in several studies where wastewater was filtrated through biochar in granulated form (Huggins et al., 2016). Further, biochar has been shown to sorb pharmaceuticals from urine without removing nutrients (Solanki & Boyer, 2017). In this paper, results from experimental tests on addition of biochar in the primary settler will be presented. Experiments are made in lab-scale to test the adsorption and settling capacity depending on biochar properties, e.g. particle size, cation exchange capacity. The theoretical dosing requirement in a full scale application and possible biochar yields from pyrolysis of primary sludge are also investigated.

  • 124.
    Sylwan, Ida
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Runtti, Hanna
    Oulu University, Finland.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zambrano, Jesus
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Westholm, Lena Johansson
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    BIOCHAR ADSORPTION FOR SEPARATION OF HEAVY METALSIN MUNICIPAL WASTEWATER TREATMENT2018Konferansepaper (Annet vitenskapelig)
  • 125.
    Sylwan, Ida
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zambrano, Jesus
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Energy demand for phosphorus recovery from municipal wastewater2019Inngår i: Innovative Solutions for Energy Transitions / [ed] Elsevier, 2019, Vol. 158, s. 4338-4343Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Phosphorus (P) is one of the essential nutrients for production of food. In modern agriculture, a large part of P comes from finite sources. There are several suggested processes for reuse of P from wastewater. In this paper, the energy use of direct reuse of sludge in agriculture is compared to the energy demand connected to use of mineral P and to reuse of P after thermal processing of sludge. The study is based on literature data from life cycle analysis (LCA). In the case of direct sludge reuse the sludge stabilization processes applied and the system boundaries of the LCA has a large impact on the calculated energy demand. The results though indicate that direct reuse of sludge in agriculture is the reuse scenario that potentially has the lowest energy demand (3-71 kWh/kg P), compared to incineration and extraction of P from sludge ashes (45-70 kWh/kg P) or pyrolysis of sludge (46-235 kWh/kg P). The competitiveness compared to mineral P (-4-22 kWh/kg P) depends on the mineral P source and production. For thermal processing, the energy demand derives mainly from energy needed to dry sludge and supplement fuel used during sludge incineration together with chemicals required to extract P. Local conditions, such as available waste heat for drying, can make one of these scenarios preferable.

  • 126.
    Tan, Y.
    et al.
    Royal Institute of Technology, Stockholm, Sweden.
    Nookuea, Worrada
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Stockholm, Sweden.
    Cryogenic technology for biogas upgrading combined with carbon capture-a review of systems and property impacts2017Inngår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 3741-3746Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    CO2 makes a major contribution to the climate change, and biomass renewable energy and carbon capture and storage (CCS) can be deployed to mitigate the CO2 emission. Cryogenic process for biogas upgrading combined with carbon capture is one of the most promising technologies. This paper reviewed the state-of-the-art of cryogenic systems for biogas upgrading combined with carbon capture, and introduced the status and progress of property impacts on the cryogenic systems with emphasize on phase equilibrium. The existing cryogenic systems can be classified as flash liquefaction system, distillation system, and liquefaction combined with desublimation system. The flash liquefaction system produces biomethane and CO2 in lower purity than the other two systems. Thermodynamic optimization on the flash liquefaction system and liquefaction combined with desublimation system should be done further, and comprehensive comparison between three cryogenic systems needs to be carried out. As to the phase equilibrium, PR EOS is safe to be used in predicting VLE and SVLE with an independent thermodynamic model describing the fugacity of the solid phase. However, the impacts of binary mixing parameter, different EOS models and mixing rules, on the performance of the cryogenic system need to be identified in the future. 

  • 127.
    Tan, Y.
    et al.
    School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Nookuea, Worrada
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Evaluation of viscosity and thermal conductivity models for CO2 mixtures applied in CO2 cryogenic process in carbon capture and storage (CCS)2017Inngår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 123, s. 721-733Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The cryogenic process is used for CO2 purification in oxy-fuel combustion power plant, and multi-stream heat exchanger is one of the most important components. Viscosity and thermal conductivity are key transport properties in the design of plate-fin multi-stream heat exchanger. It is necessary to evaluate the impacts of viscosity and thermal conductivity models on the design of the heat exchanger. In this paper, different viscosity models and thermal conductivity models for CO2 mixtures with non-condensable impurities were first evaluated separately by comparing the calculated results with experimental data. Results show that for viscosity, the absolute average deviation of KRW model is the smallest, which is 1.3%. For thermal conductivity, model developed by Ely and Hanley, with absolute average deviation of 3.5%, is recommended. The impact of property models on the design of plate-fin multi-stream heat exchanger was also analyzed. The thermal conductivity model has a noticeable impact on the plate-fin multi-stream heat exchanger design, and the deviation in design size of heat exchanger by using different thermal conductivity models may reach up to 7.5%. The future work on how to improve the property models was discussed. © 2017 Elsevier Ltd

  • 128. Tan, Y.
    et al.
    Nookuea, Worrada
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Impacts of thermos-physical properties on plate-fin multi-stream heat exchanger design in cryogenic process for CO2 capture2019Inngår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 149, s. 1445-1453Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Oxy-fuel combustion is one of the most promising technologies for CO2 capture for power plants. In oxy-fuel combustion plants, cryogenic process can be applied for CO2 purification because the main impurities in flue gas are non-condensable gases. The multi-stream plate-fin heat exchanger is one of the most important components in the CO2 cryogenic system. In-depth understanding of the impacts of property on the heat exchanger is of importance for appropriate design. In order to investigate the impacts of properties on sizing the heat exchanger and to further identify the key properties to be prioritized for the property model development, this paper presented the design procedure for the plate-fin multi-stream heat exchanger for the CO2 cryogenic process. Sensitivity study was conducted to analyze the impacts of thermos-physical properties including density, viscosity, heat capacity and thermal conductivity. The results show that thermal conductivity has the most significant impact and hence, developing a more accurate thermal conductivity model is more important for the heat exchanger design. In addition, even though viscosity has less significant impact compared to other properties, the larger deviation range of current viscosity models may lead to higher uncertainties in volume design and annual capital cost of heat exchanger. 

  • 129.
    Tan, Y.
    et al.
    Royal Institute of Technology, Stockholm, Sweden.
    Nookuea, Worrada
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Property impacts on Carbon Capture and Storage (CCS) processes: A review2016Inngår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 118, s. 204-222Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The knowledge of thermodynamic and transport properties of CO2-mixtures is important for designing and operating different processes in carbon capture and storage systems. A literature survey was conducted to review the impact of uncertainty in thermos-physical properties on the design and operation of components and processes involved in CO2 capture, conditioning, transport and storage. According to the existing studies on property impacts, liquid phase viscosity and diffusivity as well as gas phase diffusivity significantly impact the process simulation and absorber design for chemical absorption. Moreover, the phase equilibrium is important for regenerating energy estimation. For CO2 compression and pumping processes, thermos-physical properties have more obvious impacts on pumps than on compressors. Heat capacity, density, enthalpy and entropy are the most important properties in the pumping process, whereas the compression process is more sensitive to heat capacity and compressibility. In the condensation and liquefaction process, the impacts of density, enthalpy and entropy are low on heat exchangers. For the transport process, existing studies mainly focused on property impacts on the performance of pipeline steady flow processes. Among the properties, density and heat capacity are most important. In the storage process, density and viscosity have received the most attention in property impact studies and were regarded as the most important properties in terms of storage capacity and enhanced oil recovery rate. However, for physical absorption, physical adsorption and membrane separation, there has been a knowledge gap about the property impact. In addition, due to the lack of experimental data and process complexity, little information is available about the influence of liquid phase properties on the design of the absorber and desorber for chemical absorption process. In the CO2 conditioning process, knowledge of the impacts of properties beyond density and enthalpy is insufficient. In the transport process, greater attention should focus on property impacts on transient transport processes and ship transport systems. In the storage process, additional research is required on the dispersion process in enhanced oil recovery and the dissolution process in ocean and saline aquifer storage.

  • 130.
    Tan, Yuting
    et al.
    Royal Institute of Technology, Sweden.
    Nookuea, Worrada
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Institute of Technology, Sweden.
    Property Impacts on Plate-fin Multi-stream Heat Exchanger (Cold Box) Design in CO2Cryogenic Process: Part I. Heat Exchanger Modeling and Sensitivity Study2017Inngår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 05, s. 4587-4594Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The multi-streamplate-finheat exchanger is one of the most important componentsin the CO2 cryogenic system. Appropriate design methodology and in-depth analysis of property on the heat exchanger are of importance. This paper, as part I of the two-paper series, presented the design procedure for the multi-stream plate-fin heat exchangerin CO2 cryogenic process. Sensitivity study was also conducted to analyze the impacts of thermos-physical properties including density, viscosity, heat capacity and thermal conductivity.

    The results show that thermal conductivity has the most significant impact and it should be prioritized to develop a more accurate thermal conductivity model for the heat exchanger design. In addition, viscosity has least significant impact but the higher uncertainty range of viscosity may lead to a higher possible deviation in volume design.

  • 131.
    Tan, Yuting
    et al.
    Royal Inst Technol, Sweden.
    Nookuea, Worrada
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Li, Hailong
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Zhao, Li
    Tianjin Univ, Peoples R China.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. Royal Inst Technol, Sweden.
    Property impacts on performance of CO2 pipeline transport2015Inngår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 75, s. 2261-2267Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Carbon Capture and Storage (CCS) is one of the most potential technologies to mitigate climate change. Using pipelines to transport CO2 from emission sources to storage sites is one of common and mature technologies. The design and operation of pipeline transport process requires careful considerations of thermo-physical properties. This paper studied the impact of properties, including density, viscosity, thermal conductivity and heat capacity, on the performance of CO2 pipeline transport. The pressure loss and temperature drop in steady state were calculated by using homogenous friction model and Sukhof temperature drop theory, respectively. The results of sensitivity study show that over-estimating density and viscosity increases the pressure loss while under-estimating of density and viscosity decreases it. Over-estimating density and heat capacity leads to lower temperature drop while underestimating of density and heat capacity result in higher temperature drop. This study suggests that the accuracy of property models for example, more accurate density model, should be developed for the CO2 transport design. 

  • 132.
    Thorin, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Basics of Energy2014Inngår i: Reference Module in Earth Systems and Environmental Sciences, 2014, Elsevier, 2014Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    The basics of energy include using an energy source and converting it, sometimes in several different steps, into useable energy products. Solar radiation is a flowing energy source, while fossil fuels and nuclear energy are stored sources. The sources utilized by the society are dominated by the stored sources and only a very small part of the incoming solar energy is used. The energy use can be divided into three sectors: industry, transportation, and buildings. The shares of the total energy use for the different sectors are about the same and also were 40 years ago

  • 133.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling. Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Ahrens, Thorsten
    Ostfalia University.
    Hakalehto, Elias
    University of Eastern Finland.
    Jääskeläinen, Ari
    Savonia University of Applied Sciences.
    Organic waste as a biomass resource2013Inngår i: Biomass as Energy Source: Resources, Systems and Applications / [ed] Erik Dahlquist, CRC Press, 2013, s. 109-133Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 134.
    Thorin, Eva
    et al.
    Mälardalens högskola, Institutionen för samhällsteknik.
    Brand, Heike
    University of Stuttgart, Germany.
    Weber, Christoph
    University of Stuttgart, Germany.
    Long-term Optimization of Cogeneration Systems in a Competitive Market Environment2005Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 81, nr 2, s. 152-169Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A tool for long-term optimization of cogeneration systems is developed that is based on mixed integer linear programming and Lagrangian relaxation. We use a general approach without heuristics to solve the optimization problem of the unit commitment problem and load dispatch. The possibility to buy and sell electric power at a spot market is considered as well as the possibility to provide secondary reserve. The tool has been tested on a demonstration system based on an existing combined heat and power (CHP) system with extraction-condensing steam turbines, gas turbines, boilers for heat production and district heating networks. The key feature of the model for obtaining solutions within reasonable times is a suitable division of the whole optimization period into overlapping subperiods. Using Lagrangian relaxation the tool can be applied to large CHP systems. For the demonstration model almost optimal solutions were found.

  • 135.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Daianova, Lilia
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Guziana, Bozena
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Wallin, Fredrik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Wossmar, Susanne
    Handelskammaren Mälardalen.
    Degerfeldt, Viveka
    Handelskammaren Mälardalen.
    Granath, Lennart
    Länsstyrelsen Västmanland.
    CURRENT STATUS OF THE WASTE- TO- ENERGY CHAIN IN THE COUNTY OF VÄSTMANLAND, SWEDEN2011Rapport (Annet (populærvitenskap, debatt, mm))
  • 136.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Daianova, Lilia
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Lindmark, Johan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nordlander, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Song, Han
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Jääskeläinen, Ari
    The Municipal Federation of Savonia University of Applied Sciences.
    Malo, Laura
    Centre for Economic Development, Transport and the Environment for North Savo (CNS).
    den Boer, Emilia
    Institute of Environment Protection Engineering, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
    den Boer, Jan
    WAMECO S.C., ul. Malinowa 7, 55-002 Kamieniec Wrocławski, Poland.
    Szpadt, Ryszard
    Institute of Environment Protection Engineering, Wrocław University of Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
    Belous, Olga
    Klaipeda University (KLU).
    Kaus, Taivo
    Estonian Regional and Local Development Agency (ERKAS).
    Käger, Marja
    Estonian Regional and Local Development Agency (ERKAS).
    State of the art In the Waste to Energy Area: Technology and Systems2011Rapport (Annet vitenskapelig)
  • 137.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    den Boer, Emilia
    Institute of Environment Protection Engineering, Wrocław University of Technology.
    Belous, Olga
    Klaipeda University.
    Song, Han
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Waste to Energy- a review2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Waste materials can be used as a valuable resource for reuse, recycling or energy recovery. In this paper a review on using waste as energy resource, done in the REMOWE project, included in the EU funded Baltic Sea Region Programme, is presented. Five main conversion paths have been identified; combustion, pyrolysis, gasification, anaerobic digestion and fermentation. Combustion and anaerobic digestion are mature and well-proven technologies for waste treatment but improvements are needed to make the processes more efficient as energy conversion processes. For anaerobic digestion feedstock pre-treatment, avoidance of inhibition, mixing, residues utilization, and monitoring and control are identified development areas. A more recent trend is development of dry digestion technology for the treatment of municipal waste. The possible improvements of the combustion process using waste as fuel includes plant efficiency, improved emission control and ash handling. Pyrolysis and gasification have been used for waste treatment but the technologies are still in the development stage. Identified development areas are process operation conditions, gas and by-product quality, gas cleaning and plant efficiency.

    Studies comparing waste to energy systems found do not give a clear picture of what waste to energy technology that is most favourable. The results of the comparisons are dependent on the conditions chosen for the study such as location, economic activities, population, and possible system combinations.

  • 138.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Guziana, Bozena
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Song, Han
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Jääskeläinen, Ari
    The Municipal Federation of Savonia University of Applied Sciences .
    Szpadt, Ryszard
    Wroclaw University of Technology / Institute of Environmental Protection Engineering.
    Vasilic, Dejan
    Ostfalia University of Applied Sciences, Fachhochschule Braunschweig / Wolfenbüttel.
    Ahrens, Thorsten
    Ostfalia University of Applied Sciences, Fachhochschule Braunschweig / Wolfenbüttel.
    Anne, Olga
    Klaipeda University .
    Lõõnik, Jaan
    Estonian Regional and Local Development Agency (ERKAS).
    Potential future waste-to-energy systems2012Rapport (Annet vitenskapelig)
    Abstract [en]

    This report discusses potential future systems for waste-to-energy production in the Baltic Sea Region, and especially for the project REMOWE partner regions, the County of Västmanland in Sweden, Northern Savo in Finland, Lower Silesia in Poland, western part of Lithuania and Estonia.

    The waste-to-energy systems planned for in the partner regions are combustion of municipal solid waste (MSW) and solid recovered fuels from household and industry as well as anaerobic digestion of sewage sludge and agriculture waste.

    The potential future waste-to-energy systems in the partner regions include increased utilization of available waste resources. Examples of resources possible to use are straw that could be used for ethanol production and biowaste from households and manure that could be used for biogas production. If the utilization in all partner regions would reach the same level as already exists in the County of Västmanland it would correspond to an increased energy supply of 3 TWh/year which corresponds to about 2.5 % of the total energy use in the partner regions year 2008.

    An important aspect of future anaerobic processes for biogas production is the possibility to use the residue. West Lithuanian biogas production residue is planned to be dewatered up to 90 % of dry matter to make future utilization options possible.

    Pre-processing is necessary to be able to use the residue from digestion of solid waste as fertilizer. The pre-processing should include crushing, removal of metals, wood and plastics, and pulping. Without pre-processing it is possible to combust the residues with energy utilisation. Results from an investigation of the residues from biogas production tests using substrates from the project partner regions show a remaining energy potential of the digestate corresponding to 17 to 50% of the biogas energy. A combination of digestate combustion and fertilizer use could be a possibility.

    Hydrothermal carbonization, HTC, is a process that could be of interest to use for treating digestate in order both to utilize the energy left after biogas production but also for sanitation of the digestate. In this process heat is released and coal is produced. This process could also be of interest for waste-to-energy conversion of waste which is usually not usable for other biological process like e.g. biogas production, for example sharp leaved rush, straw or leaves from gardening etc. Initial tests on pulp and paper waste show promising results.

    Among the possible processes for increasing the output of biogas from anaerobic digestion using ultrasound technology for thickening of surplus waste water sludge can be mentioned. It allows increasing the biogas production up to 30 % and reducing the amount of organic substances in the digested sewage sludge by up to 25 %. Another area of possible improvement is the mixing in the digester. The mixing is important for distribution of microorganisms and nutrition, inoculation of fresh feed, homogenizing of the material and for the removal of end products of the metabolism. Studies of the digester for biowaste in the County of Västmanland indicate that about 30 % of digester volume can have dead and stagnant zones.

    2

    Waste-to-energy utilisation could also be possible to realise by further development and introduction of new processes and concepts. An option for solving the problem of old sewage sludge could be to use it in a gasifier to convert it to energy rich gases. Microbiological conversion of waste can be further developed to produce several different products, such as heat, power, fuels and chemicals, the development of so-called biorefineries. Also the biorefinery‘s water management can be renewed in order to remove toxic substances, minimize environmental impacts and produce pure, clean water. Finnoflag Oy has developed a technology that converts waste materials into e.g. fuels, chemicals, plastic and rubber via low-energy routes. The Finnoflag technology is based on the PMEU (Portable Microbe Enrichment Unit) which is a new innovative instrument for use in the microbe detection process and that is designed to create an optimal growth environment for microbes.

    For fibrous and well-structured biowaste dry digestion could be a good option for biogas production. Several different configurations have been tested in Germany. The garage digestion method has the advantage that an extensive pre- treatment of substrate is not necessary and no pumps or stirrers, which can be destroyed by disturbing materials, are involved. However, the efficiency of garage digesters is low compared to other digestion methods due to lack of effective substrate turbation. More research work is needed to improve the efficiency. Tests of five existing dry digestion processes show that the Tower-digester is the most suitable dry digestion method for household waste. Among the reviewed plants the Dranco-tower digester showed the best efficiency in reference to biogas potential. The plant design is robust enough to handle substrates like household waste with fractions of disturbing materials. The mixing in the reactor is based on the force of gravity and the used pumps are powerful and very resistant.

    Pyrolysis is a process of interest for converting wood based waste into energy products such as gas, bio-oil and/or solid fuel/carbon. This has been identified as a process suitable for a new business model with a franchise based model, offering an earning opportunity for small size entrepreneurs.

    Possible improvement of existing and new waste-to-energy systems also includes increasing the overall efficiency of the utilization of waste resources by integration of several processes. A study on integrating pellets production from the residues from straw-based ethanol production with an existing combined heat and power plant shows that the total production cost can be reduced by the integration.

    Possible development of waste-to-energy systems for the partner regions could be the following:

     Estonian - biogas production using the organic waste, use of the digestate as fertilizer on demand or combustion for power and heat production, recycling plants for paper, plastics and other recyclable wastes and combustion for power and heat production after recycling

     North Savo, Finland- the same options as for Estonia is of interest. Added to this is the potential for power and heat production from large amount of wood waste. Also the possibility for pellet production from wood waste could be of interest.

     Western Lithuania- the same system as mentioned for Finland is also of interest for western Lithuania.

    3

     

     Lower Silesia, Poland- also for Lower Silesia high amounts of organic wastes is suitable to use for biogas production in anaerobic digestion. Recovered derived fuel (RDF) is already used as fuel for power and heat production. There are also some attempts to involve combustion of residual mixed waste in 1-2 of the most densely populated areas.

     County of Västmanland, Sweden- Here a system for separate collection of the biowaste from households, digestion of the fraction together with ley crop silage from regional farmers to produce biogas and use of the digestate from the digestion process as fertilizer at farmland already exists and a new power and heat plant using recovered derived fuels is under construction. Further waste- to-energy plants for production of bioethanol from straw and biogas from agricultural waste could be possible.

    The potential future waste-to-energy systems are not only dependent on available technologies for waste-to-energy conversion but also on the development within the waste and energy areas including also economic and political aspects. There is a growing interest for waste prevention in waste management within the EU, and growing concern about food losses and food waste at global and national levels. During past decades the waste amounts have steadily increased with economic growth but due to waste prevention actions a decoupling of the waste amount and economic growth is foreseen. This has to be considered in development of future waste-to-energy systems. Further, policies and goals concerning fossil fuel free transportation systems and low carbon energy systems is of importance.

    Analysis of combined previous proposed scenarios for energy demand and use development and waste amount development for waste-to-energy in Sweden 2010 to 2050 shows that the contribution of waste-to-energy to the total energy supply in 2050 varies from 6 to 47 % depending on the scenarios combined. The lowest contribution occur for scenarios with low waste amounts combined with energy scenarios with low changes in energy demand while the highest contribution occurs for scenarios with high amount of waste combined with energy scenarios with large decrease in energy demand.

  • 139.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Li, Hailong
    Chemical Engineering and Technology/Energy Processes, Royal Institute of Technology.
    Yan, Jinuye
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    On thermophysical properties of CO2/H2O mixtures with impurities in oxyfuel CCS systems2009Inngår i: IOP Conf. Series: Earth and Environmental Science 6 (2009), 2009Konferansepaper (Annet vitenskapelig)
  • 140.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Lindmark, Johan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Kastensson, Jan
    Pettersson, Carl-Magnus
    Persson, Per-Erik
    PERFOMANCE OPTIMIZATION OF THE VÄXTKRAFT BIOGAS PRODUCTION PLANT –THE USE OF MEMBRANE FILTRATION2009Inngår i: Proceedings of ICAE'09, 2009, s. 594-602Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Today we can see a large potential for biogas production from any kind of organic residue as well as from different crops, farm land residues or graze. However, the technology for biogas production is not optimized and thus not fully cost-effective. To be fully commercially competitive with other types of fuels, efficiency improvements of the process are needed. In the research project BioGasOpt, performed in cooperation between Mälardalen University and industry, performance optimization of the Växtkraft biogas production plant and surrounding systems are studied.  In this paper the project will be presented and the possibility for improvements by using membrane filtration to reduce the dry matter in the recirculated water is addressed.

    In the Växtkraft biogas plant, in Västerås, Sweden, organic wastes from households and restaurants are mixed and fermented with crops from graze land. A lot of water is used in the process and the surplus is filtered off in decanter centrifuges. The decantate from the centrifuges is partly recirculated in the process and the problem is that the content of dry matter in the decantate is increasing and is today around 4 %.  In this paper the potential to use membrane filtration to improve the performance of biogas plants is studied. The consequences concerning production capacity, energy use, and operation of the plant are discussed. The first results from tests on using ceramic membrane filters at the Växtkraft biogas plant show that it possible to decrease the content of dry matter in the process water to 2 % at operation temperatures around 100˚C.   

  • 141.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Lindmark, Johan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nordlander, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Kastensson, Jan
    Mercatus Engineering AB.
    Leksell, Niklas
    Svensk Växtkraft AB.
    Pettersson, Carl-Magnus
    Svensk Växtkraft AB.
    Performance Optimization of the Växtkraft Biogas Production Plant2011Inngår i: ICAE2011 - International Conference on Applied Energy, 2011, s. 1833-1844Konferansepaper (Fagfellevurdert)
    Abstract [en]

    All over the world there is a strong interest and also potential for biogas production fromorganic residues as well as from different crops. However, to be commercially competitive withother types of fuels, efficiency improvements of the biogas production process are needed. In this paper the results of the project BioGasOpt, Performance optimization of the Växtkraft biogas production plant and surrounding system, are summarized. The project is performed in cooperation between Mälardalen University, the biogas plant Svensk Växtkraft AB, the membrane filtration company Mercatus Engineering AB and the farm Nibble Lantbruk AB.

    In the Växtkraft biogas plant organic wastes from households and restaurants are mixed and digested with crops from graze land. Four areas of importance for the performance of the plant are addressed in the BioGasOpt project: treatment of the feed material to enhance the fermentation rate, transport performance of gas and nutrients in the reactor, limitation of the ballast of organics in the water stream recirculated in the process, and use of the biogas plant residues at farms.

    The results indicate a potential to increase the biogas yield from the process with up to 40 % with pre-treatment of the feed and including membrane filtration in the process. The possibilities to improve the mixing in the digester also show a significant potential for even higher biogas yields. Modelling of the biogas process for better process control is also identified as a possible way to further improve the biogas yield. However, model development taking into account what input data is possible to get at a biogas plant in operation is needed.

    Further, the results from the project show that the residues from biogas production can be used as fertilizers but that the emission of N2O from the fertilised soil is dependent on the soil type and spreading technology.

  • 142.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Lindmark, Johan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nordlander, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Odlare, Monica
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik.
    Kastensson, Jan
    Mercatus Engineering AB.
    Leksell, Niklas
    Svensk Växtkraft AB.
    Pettersson, Carl-Magnus
    Svensk Växtkraft AB.
    Performance optimization of the Växtkraft biogas production plant2012Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 97, s. 503-508Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    All over the world there is a strong interest and also potential for biogas production from organic residues as well as from different crops. However, to be commercially competitive with other types of fuels, efficiency improvements of the biogas production process are needed. In this paper, results of improvements studies done on a full scale co-digestion plant are presented

     

    In the plant organic wastes from households and restaurants are mixed and digested with crops from graze land. The areas for improvements of the plant addressed are treatment of the feed material to enhance the digestion rate, limitation of the ballast of organics in the water stream recirculated in the process, and use of the biogas plant residues at farms. Results from previous studies on pre-treatment and membrane filtration of recirculated process water are combined for estimation of the total improvement potential. Further, the possibility to use neural networks to predict biogas production using historical data from the full-scale biogas plant was investigated. Results from investigation of using the process residues as fertilizer are also presented.

     

    The results indicates a potential to increase the biogas yield from the process with up to over  30 % with pre-treatment of the feed and including membrane filtration in the process. Neural networks have the potential to be used for prediction of biogas production. Further, it is shown that the residues from biogas production can be used as fertilizers but that the emission of N2O from the fertilised soil is dependent on the soil type and spreading technology.

  • 143.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindmark, Johan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Freidank, Tim
    Ostfalia University of Applied Sciences.
    Drescher-Hartung, Silvia
    Ostfalia University of Applied Sciences.
    Daukšys, Vygintas
    Klaipeda University.
    Ahrens, Thorsten
    Ostfalia University of Applied Sciences.
    POSSIBILITES FOR OPTIMIZATION OF THE DRY DIGESTION PROCESS2014Rapport (Annet vitenskapelig)
  • 144.
    Thorin, Eva
    et al.
    Mälardalens högskola, Institutionen för samhällsteknik.
    Manbo, Thomas
    Mälardalens högskola, Institutionen för samhällsteknik.
    Jacobson, Henrik
    Mälardalens högskola, Institutionen för samhällsteknik.
    Tommy, Törnqvist
    Mälardalens högskola, Institutionen för samhälls- och beteendevetenskap.
    Examination med hjälp av dagbok- erfarenheter från en kurs tillhörande civilingenjörsutbildningen i samhällsteknik vid Mälardalens högskola2007Annet (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    Ett intressant sätt att kombinera examination och inlärning är att examinera genom att studenterna under kursens gång får skriva dagbok och göra reflektioner över sin egen inlärning. Fördelen är också att det befrämjar kontinuerlig inlärning. Vi har provat denna examinationsform i en kurs tillhörande årskurs 4 inom vår civilingenjörsutbildning (civilingenjör i samhällsteknik). En stor del av kursen består av ett projektarbete och anledningen till att vi från början valde dagbok som examinationsform var att vi bedömde att vi därmed skulle få större möjligheter att göra en rättvis bedömning av studenternas individuella kunskaper. Kursen gick första gången under vårterminen 2006 och för andra gången vårtterminen 2007. Våra erfarenheter är övervägande positiva men det finns också nackdelar och svårigheter som t ex lärarinsats, studenters ovana vid formen och kriterier för betygssättning.

  • 145.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Nordlander, Eva
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Lindmark, Johan
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Dahlquist, Erik
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Yan, Jinyue
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    Bel Fdhila, Rebei
    Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling.
    MODELING OF THE BIOGAS PRODUCTION PROCESS- A REVIEW2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Production of biogas by digestion of organic wastes and other feedstock is one of the important technical solutions that contribute to the transform of the energy system from being fossil fuel dependent to renewable energy originated. To be fully commercial and competitive, the production of biogas needs to be further developed and optimized based on the technical, economic and environmental aspects. Thus, comprehensive understanding of fluid dynamics and microbial reactions in the digestion process is necessary to accurately and robustly model, predict and control the biogas production.

    In this paper possible pathways for modeling the biogas reactor is discussed based on previous work on anaerobic digestion modeling and modeling of the fluid flow in reactors. Important parameters for modeling biogas production, with a focus on processes using waste as feedstock, are considered. Identification of knowledge gaps for the modeling of the biogas process is performed and how to overcome the obstacles is addressed.

  • 146.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nordlander, Eva
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindmark, Johan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Jansson, Joakim
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Hakalehto, Elias
    Finnoflag.
    Heitto, Anneli
    Finnoflag.
    Jääskeläinen, Ari
    Savonia University of Applied Sciences.
    Suhonen,, Anssi
    Savonia University of Applied Sciences.
    Den Boer, Emilia
    Wrocław University of Technology.
    Possibilites for Optimization of Biorefinery process2014Rapport (Annet vitenskapelig)
  • 147.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Olsson, Jesper
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Biogas from Co-digestion of Sewage Sludge and Microalgae2017Inngår i: Energy Procedia, 2017, Vol. 105, s. 1037-1042Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Microalgae cultivated in waste water could contribute to increased biomass production at municipal waste watertreatment plants. The biomass could be utilized for biogas production when co-digested with sewage sludge. In thispaper previous published results on co-digestion of sewage sludge and microalgae are summarized and remainingknowledge gaps are identified. The available batch tests in literature mostly concern digestion at mesophilicconditions. Some of those tests indicate a synergetic effect for the co-digestion. Investigations at thermophilicconditions and of semi-continuous processes are scarce. The available results show good possibilities for co-digestionof sewage sludge and microalgae. Further investigations are needed to find optimal conditions for biogas production.

  • 148.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Olsson, Jesper
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Nehrenheim, Emma
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Co-digestion of sewage sludge and microalgae: Biogas production investigations2018Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 227, s. 64-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In municipal wastewater treatment plants (WWTPs), algae could be utilised for cleaning the water and, at thesame time, produce a biomass that can be used for energy. Through anaerobic digestion, microalgae can contributeto biogas production when co-digested with sewage sludge. In this paper, previous published results onthe co-digestion of sewage sludge and microalgae are summarised and reviewed, and any remaining knowledgegaps are identified. The batch tests currently documented in literature mostly concern digestion under mesophilicconditions, and studies investigating thermophilic conditions are less common. The average biochemicalmethane potential (BMP) for 29 different mixtures co-digested under mesophilic conditions is 317 ± 101 N cm3CH4 gVS−1 while the result for 12 different mixtures investigated under thermophilic conditions is a BMP of318 ± 60 N cm3 CH4 gVS−1. An evaluation of the heat required for increasing the temperature from mesophilicto thermophilic conditions shows that increased methane production under thermophilic conditions can beenough to create a positive energy balance. For a full-scale WWTP, using thermophilic digestion on sludge, or acombination of sludge and microalgae could therefore be of interest. This is dependent on the demands onsanitation of the sludge and the possibilities for heat recovery.Most of the mesophilic investigations indicate a synergetic effect for co-digestion, with enhancements of up toalmost 70%. However, the results are uncertain since the standard deviations for some of the BMP tests are in thesame order of magnitude as the identified enhancement. Neither of the presented publications provide an understandingof the basic mechanisms that led to higher or lower BMP when microalgae were mixed with wastewatersludge. We, therefore, call for care to be taken when assuming any effects related to the specification ofsubstrates. Microalgae and wastewater sludge have several similarities, and the specific results of BMP in themixtures relate more to the specifics of the respective materials than the materials themselves.Investigations into semi-continuous processes of co-digestion of microalgae and sludge are scarce. The yieldsfor three co-digestion studies show high variation, with an average of 293 ± 112 N cm3 gVSin−1. The availableresults show strong potential for co-digestion of sewage sludge and microalgae. Further investigations are requiredto identify optimal conditions for biogas production, and analysis of microalgae implementation onwastewater treatment at a system level is also needed to identify the total mass balance of substrate and nutrientrecovery.

  • 149.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Sandberg, Jan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Yan, Jinyue
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi. KTH, Sweden.
    Combined Heat and Power2015Inngår i: Handbook of Clean Energy Systems, John Wiley & Sons, 2015Kapittel i bok, del av antologi (Fagfellevurdert)
  • 150.
    Thorin, Eva
    et al.
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Schwede, Sebastian
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Lindmark, Johan
    Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, Framtidens energi.
    Ahrens, Torsten
    Ostfalia University of Applied Science, Wolfenbüttel, Germany.
    DRY DIGESTION PILOT TESTS USING RESIDUAL MUNICIPAL WASTE AS SUBSTRATE2015Inngår i: Sardinia 2015 / [ed] Raffaello Cossu et al, Padova: CISA publisher , 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A pilot plug-flow dry digestion process was tested for production of biogas from the fine fraction of the residual municipal solid waste after source sorting of the organic fraction of the waste. The residual waste is complex, containing a mix of hard and soft plastic, paper, metal, glass, and a varying amount of organic material. The utilization as a substrate for biogas production is therefore challenging. The purpose of the pilot tests was to determine if it is technically feasible to produce biogas from this waste. The plant was operated under thermophilic conditions for almost three months. In parallel also a garage fermentation batch pilot plant was tested with the same substrate. The results from the tests are promising concerning the biogas production even if there are indications that the process in the plug-flow reactor was operated in so called inhibited steady state at the higher loading rates.

1234 101 - 150 of 159
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