https://www.mdu.se/

mdu.sePublications
Change search
Refine search result
1234 151 - 185 of 185
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 151.
    Tan, Y.
    et al.
    School of Chemical Science and Engineering, Royal Institute of Technology, Stockholm, Sweden.
    Nookuea, Worrada
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. 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)2017In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 123, p. 721-733Article in journal (Refereed)
    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

  • 152. Tan, Y.
    et al.
    Nookuea, Worrada
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, China.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. 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 capture2019In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 149, p. 1445-1453Article in journal (Refereed)
    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. 

  • 153.
    Tan, Y.
    et al.
    Royal Institute of Technology, Stockholm, Sweden.
    Nookuea, Worrada
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Property impacts on Carbon Capture and Storage (CCS) processes: A review2016In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 118, p. 204-222Article in journal (Refereed)
    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.

  • 154.
    Tan, Yuting
    et al.
    Royal Institute of Technology, Sweden.
    Nookuea, Worrada
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. 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 Study2017In: Energy Procedia, ISSN 1876-6102, Vol. 05, p. 4587-4594Article in journal (Refereed)
    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.

    Download full text (pdf)
    fulltext
  • 155.
    Tan, Yuting
    et al.
    Royal Inst Technol, Sweden.
    Nookuea, Worrada
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Zhao, Li
    Tianjin Univ, Peoples R China.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Inst Technol, Sweden.
    Property impacts on performance of CO2 pipeline transport2015In: Energy Procedia, ISSN 1876-6102, Vol. 75, p. 2261-2267Article in journal (Refereed)
    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. 

  • 156.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Basics of Energy2014In: Reference Module in Earth Systems and Environmental Sciences, 2014, Elsevier, 2014Chapter in book (Other academic)
    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

    Download full text (pdf)
    fulltext
  • 157.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology. Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Ahrens, Thorsten
    Ostfalia University.
    Hakalehto, Elias
    University of Eastern Finland.
    Jääskeläinen, Ari
    Savonia University of Applied Sciences.
    Organic waste as a biomass resource2013In: Biomass as Energy Source: Resources, Systems and Applications / [ed] Erik Dahlquist, CRC Press, 2013, p. 109-133Chapter in book (Other academic)
  • 158.
    Thorin, Eva
    et al.
    Mälardalen University, Department of Public Technology.
    Brand, Heike
    University of Stuttgart, Germany.
    Weber, Christoph
    University of Stuttgart, Germany.
    Long-term Optimization of Cogeneration Systems in a Competitive Market Environment2005In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 81, no 2, p. 152-169Article in journal (Refereed)
    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.

  • 159.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Daianova, Lilia
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Guziana, Bozena
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Wallin, Fredrik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    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, SWEDEN2011Report (Other (popular science, discussion, etc.))
    Download full text (pdf)
    REMOWE_WP3_Current_status_PP1_final_version
  • 160.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Daianova, Lilia
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Lindmark, Johan
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Nordlander, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Song, Han
    Mälardalen University, School of Sustainable Development of Society and Technology.
    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 Systems2011Report (Other academic)
    Download full text (pdf)
    O411_state_of_art_final
  • 161.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    den Boer, Emilia
    Institute of Environment Protection Engineering, Wrocław University of Technology.
    Belous, Olga
    Klaipeda University.
    Song, Han
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Waste to Energy- a review2012Conference paper (Refereed)
    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.

    Download full text (pdf)
    A10544
  • 162.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Guziana, Bozena
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Song, Han
    Mälardalen University, School of Sustainable Development of Society and Technology.
    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 systems2012Report (Other academic)
    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.

    Download full text (pdf)
    fulltext
  • 163.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Li, Hailong
    Chemical Engineering and Technology/Energy Processes, Royal Institute of Technology.
    Yan, Jinuye
    Mälardalen University, School of Sustainable Development of Society and Technology.
    On thermophysical properties of CO2/H2O mixtures with impurities in oxyfuel CCS systems2009In: IOP Conf. Series: Earth and Environmental Science 6 (2009), 2009Conference paper (Other academic)
  • 164.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Lindmark, Johan
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Kastensson, Jan
    Pettersson, Carl-Magnus
    Persson, Per-Erik
    PERFOMANCE OPTIMIZATION OF THE VÄXTKRAFT BIOGAS PRODUCTION PLANT –THE USE OF MEMBRANE FILTRATION2009In: Proceedings of ICAE'09, 2009, p. 594-602Conference paper (Refereed)
    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.   

  • 165.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Lindmark, Johan
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Nordlander, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Odlare, Monica
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Kastensson, Jan
    Mercatus Engineering AB.
    Leksell, Niklas
    Svensk Växtkraft AB.
    Pettersson, Carl-Magnus
    Svensk Växtkraft AB.
    Performance Optimization of the Växtkraft Biogas Production Plant2011In: ICAE2011 - International Conference on Applied Energy, 2011, p. 1833-1844Conference paper (Refereed)
    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.

  • 166.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Lindmark, Johan
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Nordlander, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Odlare, Monica
    Mälardalen University, School of Business, Society and Engineering.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering.
    Kastensson, Jan
    Mercatus Engineering AB.
    Leksell, Niklas
    Svensk Växtkraft AB.
    Pettersson, Carl-Magnus
    Svensk Växtkraft AB.
    Performance optimization of the Växtkraft biogas production plant2012In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 97, p. 503-508Article in journal (Refereed)
    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.

    Download full text (pdf)
    fulltext
  • 167.
    Thorin, Eva
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lindmark, Johan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    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 PROCESS2014Report (Other academic)
    Download full text (pdf)
    fulltext
  • 168.
    Thorin, Eva
    et al.
    Mälardalen University, Department of Public Technology.
    Manbo, Thomas
    Mälardalen University, Department of Public Technology.
    Jacobson, Henrik
    Mälardalen University, Department of Public Technology.
    Tommy, Törnqvist
    Mälardalen University, Department of Social Sciences.
    Examination med hjälp av dagbok- erfarenheter från en kurs tillhörande civilingenjörsutbildningen i samhällsteknik vid Mälardalens högskola2007Other (Other (popular science, discussion, etc.))
    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.

  • 169.
    Thorin, Eva
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Nordlander, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Lindmark, Johan
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Bel Fdhila, Rebei
    Mälardalen University, School of Sustainable Development of Society and Technology.
    MODELING OF THE BIOGAS PRODUCTION PROCESS- A REVIEW2012Conference paper (Refereed)
    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.

    Download full text (pdf)
    A10732
  • 170.
    Thorin, Eva
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Nordlander, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lindmark, Johan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Jansson, Joakim
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    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 process2014Report (Other academic)
  • 171.
    Thorin, Eva
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Olsson, Jesper
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Nehrenheim, Emma
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Biogas from Co-digestion of Sewage Sludge and Microalgae2017In: Energy Procedia, 2017, Vol. 105, p. 1037-1042Conference paper (Refereed)
    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.

    Download full text (pdf)
    fulltext
  • 172.
    Thorin, Eva
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Olsson, Jesper
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Nehrenheim, Emma
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Co-digestion of sewage sludge and microalgae: Biogas production investigations2018In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 227, p. 64-72Article in journal (Refereed)
    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.

    Download full text (pdf)
    fulltext
  • 173.
    Thorin, Eva
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Sandberg, Jan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. KTH, Sweden.
    Combined Heat and Power2015In: Handbook of Clean Energy Systems, John Wiley & Sons, 2015Chapter in book (Refereed)
    Download full text (pdf)
    fulltext
  • 174.
    Thorin, Eva
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lindmark, Johan
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Ahrens, Torsten
    Ostfalia University of Applied Science, Wolfenbüttel, Germany.
    DRY DIGESTION PILOT TESTS USING RESIDUAL MUNICIPAL WASTE AS SUBSTRATE2015In: Sardinia 2015 / [ed] Raffaello Cossu et al, Padova: CISA publisher , 2015Conference paper (Refereed)
    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.

    Download full text (pdf)
    fulltext
  • 175.
    Törnwall, Elin
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Pettersson, Hanna
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Post-treatment of biogas digestate – An evaluation of ammonium recovery, energy use and sanitation2017In: Energy Procedia, ISSN 1876-6102, Vol. 142, p. 957-963Article in journal (Refereed)
    Abstract [en]

    The utilization of digestate from anaerobic digestion (AD) processes offers the possibility to recycle nutrient from organic wastematerials back to the food chain. However, digestates are characterized by a high water content resulting in high storagecapacities and transportation costs. Various organic wastes such as organic municipal solid waste (oMSW) require sanitation withat least one hour hydraulic retention time (HRT) at 70°C to inactivate pathogens for the safe release of the material.Consequently, the sanitation process is one of the largest energy consumers in the whole AD process chain. In this study, a posttreatmentof the biogas digestate was evaluated regarding the potential for energy savings and nutrient recovery via nitrogenstripping in comparison to the conventional pre-sanitation of the organic waste. With increasing HRT (one to three hours) andaeration flow (0.0-5.3 L air per L digestate and minute) more condensate and ammonia was removed from the digestate. The totalammonia removal from the digestate after one and three hours with the highest aeration flow rate reached 42% and 80%,respectively. However, energy requirement for aeration exceeded energy savings from the lower volume for sanitation after thedigestion substantially. On a system level, a positive energy balance could still be achieved by taking energy savings from thereplacement of mineral fertilizer (36 GJ per ton NH4) into account. Moreover, the digestate as fertilizer could be applied in amore demand-oriented way by adding ammonium sulphate obtained by the ammonia stripping during the post-treatment.

  • 176.
    Wallin, Fredrik
    et al.
    Mälardalen University, Department of Public Technology.
    Bartusch, Cajsa
    Mälardalen University, Department of Public Technology.
    Thorin, Eva
    Mälardalen University, Department of Public Technology.
    Bäckström, Tobias
    Smedjebacken Energi Nät AB.
    Dahlquist, Erik
    Mälardalen University, Department of Public Technology.
    The Use of Automatic Meter Readings for a Demand-Based Tariff2005In: Proceedings of the 2005 IEEE/PES Transmission and Distribution Conference & Exhibition: Asia and Pacific, 2005, p. 1-6Conference paper (Refereed)
    Abstract [en]

    A determining factor for a successful implementation of a demand-based pricing model or control strategy in electricity markets is not only the effects of peak load management, but also the financial consequences for the utility operator and the end customer. In this economic modelling a subset of 460 residential customers has been implemented in a software tool analysing the economic outcome of three different tariffs. Two demand-based tariffs were investigated and compared with a traditional energy-based tariff. The demand-based tariffs transform the flat income curve into a more complex, due to a stronger economic dependency to the system peak loads. The demand-based tariffs move the revenues to the high-peak period, November – March, and the utility operator gains a good matching between system peaks and distribution of incomes.

  • 177.
    Wallin, Fredrik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Bartusch, Cajsa
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Important parameters for prediction of power loads - a bottom-up approach utilizing measurements from an automatic meter reading system2007In: IEEE PES Power Africa 2007 Conference and Exposition, 2007, p. 1-7Conference paper (Refereed)
  • 178.
    Wallin, Fredrik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dotzauer, Erik
    Fortum.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Automatic meter reading provides opportunities for new prognosis and simulation methods2007In: 2007 IEEE Lausanne POWERTECH, Proceedings, 2007, p. 2006-2011Conference paper (Refereed)
    Abstract [en]

    The use of top-down models, for load forecasting purposes, has been the dominating method over the last decades. However, there is now a discussion regarding the performance of the top-down models, e.g. in situations with unusual weather conditions due to the lack of historical data. This paper considers an alternative bottom-up approach with a stronger relation to the laws of physics. Electricity companies in Sweden are installing automatic meter reading systems for their customers, and using the consumption data gives new possibilities when adapting the modeling parameters in a bottom-up model for each single customer. A method for analyzing individual consumption series is suggested, where different periods in time is used to divide and identify different parts of the electricity load; base load, heat load and household loads. A review of previous work is presented, and suggestions how to link the load analysis to construction parameters for an individual building is proposed.

  • 179.
    Wallin, Fredrik
    et al.
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Kvarnström, Andreas
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Kvarnström, Johan
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Dahlquist, Erik
    Mälardalen University, School of Sustainable Development of Society and Technology.
    A method to refine electricity consumption data from automatic meter reading systems2006In: Proceedings of the 2006 International Conference on Power System Technology, IEEE , 2006, p. 1-6Conference paper (Refereed)
    Abstract [en]

    In this work data from an AMR system delivering consumption data on a daily basis with an aggregated electricity consumption post combined with a maximum peak load within the period has been utilized. The paper suggests a method to create individual hour based daily consumption profiles and to increase the knowledge of the aggregated consumption patterns over the day. As a validation the method has been applied on rearranged data from an AMR system providing hour based metering series to regenerate the same consumption series. Implementing the method can provide consumption series that can be used to increase the accuracy e.g. when forecasting the electricity consumption for individual customers. The created consumption series can also be a valuable resource when estimating aggregated hour based profiles for different areas using a bottom-up approach.

  • 180.
    Wang, Bin
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China..
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China..
    Yan, Jinying
    KTH Royal Inst Technol, Stockholm, Sweden..
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Schwede, Sebastian
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Zhu, Kai
    Tianjin Univ Commerce, Key Lab Refrigerat Technol Tianjin, Peoples R China..
    Modelling the Quench Tower in Flue Gas Cleaning of a Waste Fueled Power Plant2018In: JOINT INTERNATIONAL CONFERENCE ON ENERGY, ECOLOGY AND ENVIRONMENT ICEEE 2018 AND ELECTRIC AND INTELLIGENT VEHICLES ICEIV 2018, DESTECH PUBLICATIONS, INC , 2018Conference paper (Refereed)
    Abstract [en]

    To control the emission of pollutants in the flue gas, a separated flue gas quench was added after flue gas desulfurization and before flue gas condensation. A mathematic model was developed to simulate the heat and mass transfer in the flue gas quench. The model was validated through the comparison with measured data. Based on this model, the impacts of inlet flue gas condition and injected recycling water flow rate on the water consumption of the quench and the temperature of exit flue gas (FG) were studied. The results show that the temperature of exit FG and water consumption increased with the increase of flow rate and moisture content of FG. The temperature of exit FG increased and the water consumption decreased with the increase of droplet water diameter. The temperature of exit FG decreased and the water consumption increased with the increase of water flow rate. In order to cooled and humidified the flue gas sufficiently, the droplet diameter should be limited to 1.2 mm and the water to FG flow rate ratio (L/G) higher than 2.

  • 181. Wang, Jinshan
    et al.
    Salman, Chaudhary Awais
    Wang, Bin
    Tianjin University of Commerce, China.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Tianjin University of Commerce,.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Integrating sludge drying in biomass fueled CHP plants2021In: Energy, Ecology and Environment, ISSN 2363-7692, Vol. 6, no 1-12Article in journal (Refereed)
    Abstract [en]

    Sludge handling through thermal conversion is environmentally friendly, which, however, requires sludge drying. This work proposed to use the waste heat of flue gas (FG) to dry sludge. The integration of sludge drying in biomass fueled CHP plants can clearly affect the performance of downstream processes in FG cleaning, such as flue gas quench (FGQ) and flue gas condenser (FGC). It can further affect the energy efficiency of (CHP). In order to understand the influence, a mathematical model and an Aspen PLUS model were developed to simulate the drying process and the CHP respectively. Based on simulation results, it has been found that the increase of feeding rate of sludge and the moisture content of sludge after drying can decrease the water evaporation in FGQ. An increase of the feeding rate of sludge in combination with a drop of moisture content of sludge after drying can decrease the heat recovery from FG. After sludge is dried, it can be used as fuel to replace part of the biomass fuels. The amount of biomass saving could be influenced by the dried sludge moisture content and flow rate. The simulation results of co-incineration biomass with sludge show that the moisture content of 40% after sludge drying leads to the maximum biomass saving.

  • 182.
    Wang, Xiaoqiang
    et al.
    National Engineering Laboratory for Biomass Power Generation Equipment (NELB), School of Renewable Energy, North China Electric Power University.
    Nordlander, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Thorin, Eva
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Yan, Jinyue
    Mälardalen University, School of Sustainable Development of Society and Technology.
    Microalgal Biomethane Production Integrated with an Existing Biogas Plant: A Case Study in Sweden2012Conference paper (Refereed)
    Abstract [en]

    Microalgae are considered as potential sources for biodiesel production due to the higher growth rate than terrestrial plants. However, the large-scale application of algal biodiesel would be limited by the downstream cost of lipid extraction and the availability of water, CO2 and nutrients. A possible solution is to integrate algae cultivation with existing biogas plant, where algae can be cultivated using the discharges of CO2 and digestate as nutrient input, and then the attained biomass can be converted directly to biomethane by existing infrastructures. This integrated system is investigated and evaluated in this study. Algae are cultivated in a photobioreactor in a greenhouse, and two cultivation options (greenhouse with and without heating) are included. Life cycle assessment of the system was conducted, showing that algal biomethane production without greenhouse heating would have a net energy ratio of 1.54, which is slightly lower than that (1.78) of biomethane from ley crop. However, land requirement of the latter is approximately 68 times that of the former, because the area productivity of algae could reach at about 400 t/ha (dry basis) in half a year, while the annual productivity of ley crop is only about 5.8 t/ha. For the case of Växtkraft biogas plant in Västerås, Sweden, the integrated system has the potential to increase the annual biomethane output by 9.4 %. This new process is very simple, which might have potential for scale-up and commercial application of algal bioenergy.

    Download full text (pdf)
    R10486 Final Paper- ICAE2012- A10560
  • 183.
    Wang, Xiaoqiang
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. North China Electric Power University, Beijing.
    Nordlander, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Institute of Technology.
    Microalgal biomethane production integrated with an existing biogas plant: A case study in Sweden2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, p. 478-484Article in journal (Refereed)
    Abstract [en]

    Microalgae are considered as potential sources for biodiesel production due to the higher growth rate than terrestrial plants. However, the large-scale application of algal biodiesel would be limited by the downstream cost of lipid extraction and the availability of water, CO2 and nutrients. A possible solution is to integrate algae cultivation with existing biogas plant, where algae can be cultivated using the discharges of CO2 and digestate as nutrient input, and then the attained biomass can be converted directly to biomethane by existing infrastructures. This integrated system is investigated and evaluated in this study. Algae are cultivated in a photobioreactor in a greenhouse, and two cultivation options (greenhouse with and without heating) are included. Life cycle assessment of the system was conducted, showing that algal biomethane production without greenhouse heating would have a net energy ratio of 1.54, which is slightly lower than that (1.78) of biomethane from ley crop. However, land requirement of the latter is approximately 68 times that of the former, because the area productivity of algae could reach at about 400 t/ha (dry basis) in half a year, while the annual productivity of ley crop is only about 5.8 t/ha. For the case of Växtkraft biogas plant in Västerås, Sweden, the integrated system has the potential to increase the annual biomethane output by 9.4%. This new process is very simple, which might have potential for scale-up and commercial application of algal bioenergy. © 2013 Elsevier Ltd. All rights reserved.

  • 184.
    Xie, Y.
    et al.
    Tianjin Key Laboratory of Refrigeration Technology, Tianjin University of Commerce, Tianjin, China.
    Wang, L.
    SINTEF Energy Research, P.O. Box 4761, Torgarden, 7465, Trondheim, Norway.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Westholm, Lena Johansson
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Carvalho, Lara
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yu, Z.
    Department of Energy and Petroleum Engineering, University of Stavanger, Stavanger, 4036, Norway.
    Yu, X.
    Key Laboratory of Pressure Systems and Safety, Ministry of Education, School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, China.
    Skreiberg, Ø.
    SINTEF Energy Research, P.O. Box 4761, Torgarden, 7465, Trondheim, Norway.
    A critical review on production, modification and utilization of biochar2022In: Journal of Analytical and Applied Pyrolysis, ISSN 0165-2370, E-ISSN 1873-250X, Vol. 161, article id 105405Article in journal (Refereed)
    Abstract [en]

    There has been an increased interest in the production of sustainable biochar in the past years, as biochar shows versatile physicochemical properties and, can have a wide applicability in diverse fields. Comprehensive studies have been made to characterize biochar produced from various biomass materials, using different production technologies and under different process conditions. However, research is still lacking in correlating biochar properties needed for certain applications with (i) feedstock, (ii) biochar production processes and conditions and (iii) biochar upgrading and modification strategies. To produce biochar with desired properties, there is a great need to establish and clarify such correlations, which can guide the selection of feedstock, tuning and optimization of the production process and more efficient utilization of biochar. On the other hand, further elucidation of these correlations is also important for biochar-stakeholder and end-users for predicting physiochemical properties of biochar from certain feedstock and production conditions, assessing potential effects of biochar utilization and clearly address needs towards biochar critical properties. This review summarizes a wide range of literature on the impact of feedstocks and production processes and reactions conditions on the biochar properties and the most important biochar properties required for the different potential applications. Based on collected data, recommendations are provided for mapping out biochar production for different biochar applications. Knowledge gaps and perspectives for future research have also been identified regarding the characterization and production of biochar. 

  • 185.
    Yuting, Tan
    et al.
    Royal Institute of Technology, Sweden.
    Nookuea, Worrada
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Li, Hailong
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Yan, Jinyue
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. Royal Institute of Technology, Stockholm, Sweden.
    Property Impacts on Plate-fin Multi-stream Heat Exchanger (Cold Box) Design in CO2 Cryogenic Process: Part II. Evaluation of Viscosity and Thermal Conductivity Models2017In: Energy Procedia, ISSN 1876-6102, Vol. 105, p. 4595-4600Article in journal (Refereed)
    Abstract [en]

    Viscosity and thermal conductivity are key transport properties in the design of plate-fin multi-stream heat exchanger in CO2 cryogenic processes. It is necessary to evaluate the reliabilities of viscosity and thermal conductivity models. In addition, the differences in design of multi-stream heat exchanger by using different property models need to be studied as well. In this paper, viscosity models and thermal conductivity models of CO2 mixtures with non-condensable gas impurities were evaluated separately by comparison with existing experimental data. Recommendations were given on model selections and their impact on the design of plate-finmulti-stream heat exchanger were analyzed.

    The results show that for viscosity, the uncertainty range of Wilke’s model is the smallest with a maximum absolute deviation of 6.1%. This model is therefore recommended to be used. For thermal conductivity, GERG model, with a maximum absolute deviation of 8.7% is preferred. The choice of thermal conductivity model has a noticeabl eimpact on the plate-fin multi-stream heat exchanger design, and the maximum deviation by using different thermal conductivity models is 7.5%

    Download full text (pdf)
    fulltext
1234 151 - 185 of 185
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf