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  • 201.
    Lindmark, Johan
    et al.
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Lagerkvist, Anders
    Division of Waste Science and Technology, Luleå University of Technology, Luleå, Sweden.
    Nilsson, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Carlsson, My
    AnoxKaldnes AB, Lund, Sweden.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Evaluating the effects of electroporation pre-treatment on the biogas yield from ley crop silage.2014In: Applied Biochemistry and Biotechnology, ISSN 0273-2289, E-ISSN 1559-0291, Vol. 174, no 7, p. 2616-2625Article in journal (Refereed)
    Abstract [en]

    Exploiting the full biogas potential of some types of biomass is challenging. The complex structures of lignocellulosic biomass are difficult to break down and thus require longer retention times for the nutrients to become biologically available. It is possible to increase the digestibility of the substrate by pre-treating the material before digestion. This paper explores a pre-treatment of ley crop silage that uses electrical fields, known as electroporation (EP). Different settings of the EP equipment were tested, and the results were analyzed using a batch digestion setup. The results show that it is possible to increase the biogas yield with 16 % by subjecting the substrates to 65 pulses at a field strength of 96 kV/cm corresponding to a total energy input of 259 Wh/kg volatile solid (VS). However, at 100 pulses, a lower field strength of 48 kV/cm and the same total energy input, no effects of the treatment were observed. The energy balance of the EP treatment suggests that the yield, in the form of methane, can be up to double the electrical energy input of the process.

  • 202.
    Lindmark, Johan
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Nilsson, Erik
    Lagerkvist, Anders
    Luleå University of Technology, Division of Waste Science and Technology.
    Andreas, Lale
    Luleå University of Technology, Division of Waste Science and Technology.
    Carlsson, My
    Luleå University of Technology, Division of Waste Science and Technology.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering.
    Pretreatment of Substrate for Increased Biogas Production2010Conference paper (Refereed)
  • 203.
    Lipczynski, Marcus
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Becke, Rasmus
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Analys av fjärrvärme med värmeåtervinning via ventilationssystem: Effekterna i form av primärenergi och livscykelutsläpp av koldioxidekvivalenter2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    För att uppnå Sveriges energi- och klimatmål för energieffektivisering och koldioxidutsläpp måste nya tekniker och innovationer undersökas för att bidra till att göra energianvändningen mer effektiv i bostadssektorn. Ett alternativ för att uppnå målen är att använda ett integrerat värmesystem. De integrerade värmesystemen som undersöks i den här rapporten innefattar värmeåtervinning via ventilation som komplement till fjärrvärme, vilket jämförs med uppvärmning av bara fjärrvärme.

     

    De valda integrerade värmesystemen från HögforsGST kommer undersökas ur ett livscykelutsläpps- och primärenergiperspektiv. Analysen ska utreda om systemen bidrar till att sänka energianvändningen och hur stora livscykelutsläppen av koldioxidekvivalenter är för värmesystemen i två olika fastigheter.

     

    Slutsatsen för rapporten var att de valda integrerade värmesystemen var mer energieffektiva, då de använde mindre primärenergi, oavsett fall för elproduktion. De använde även 36 procent och 32,8 procent mindre producerad energi, för Lärlingen respektive Rundeln. Fjärrvärmesystemet medförde istället lägre totala livscykelutsläpp av koldioxidekvivalenter än det integrerade värmesystemen, för de flesta fallen av elproduktion. För att få ett mer tillförlitligt resultat bör de integrerade värmesystemen granskas under en längre tidsperiod för att vidare analysera använd primärenergi och livscykelutsläpp.

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    Analys av fjärrvärme med värmeåtervinning via ventilationssystem
  • 204.
    Liu, H.
    et al.
    Huazhong University of Science and Technology, Wuhan, China.
    Qu, L.
    Huazhong University of Science and Technology, Wuhan, China.
    Chen, Y.
    Huazhong University of Science and Technology, Wuhan, China.
    Zhang, Wennan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Yang, H.
    Huazhong University of Science and Technology, Wuhan, China.
    Wang, X.
    Huazhong University of Science and Technology, Wuhan, China.
    Chen, H.
    Huazhong University of Science and Technology, Wuhan, China.
    Physicochemical characteristics and pyrolysis kinetics of hydrothermal carbon from natural Scenedesmus2019In: Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering, ISSN 1002-6819, Vol. 35, no 14, p. 235-242Article in journal (Refereed)
    Abstract [en]

    In order to explore the utilization of natural microalgae, the natural Scenedesmus was selected to carry out hydrothermal carbonization experiments, and the characterization of its hydrochars was determined using Fourier transform infrared spectroscopy, X-ray diffraction analysis, X-ray fluorescence spectroscopy, environmental scanning electron microscopy and thermogravimetric analyzer. The results showed that the ash content of natural Scenedesmus was 44.66%, and the lipid and protein content of natural Scenedesmus were 1.4% and 15.1%, respectively. The natural microalgae ash components were mostly water-insoluble components. The main components included (Mg0.064Ca0.936CO3), SiO2, NaCl, Al2O3, CaSO4, Mg3S2O8(OH)2. After hydrothermal carbonization treatment, NaCl was dissolved in water, and the water-insoluble components were enriched in hydrochars. Compared with the natural Scenedesmus, the ash content of hydrochars increased, in the range from 57.41% to 71.47%. It was worth noting that the natural Scenedesmus and its derived hydrochars had no fixed carbon. With the increase of hydrothermal temperature, the hydrothermal carbon yield decreased from 47.29% (180℃) to 43.01% (240℃). This phenomenon was on account of the organic components in the natural Scenedesmus underwent hydrolysis, dehydration, decarboxylation, aromatization, condensation and polymerization. The carbon remaining ratio was the largest, the oxygen was the smallest, and the remaining ratios of carbon, hydrogen and oxygen decreased as the hydrothermal temperature increased. For HC-240, the removal rates of H and O were 69.88% and 93.88%, respectively, and the C remaining ration rate was 33.97%. The O/C molar ratio of hydrochars decreased from 1.45 to 0.28. Dehydration and decarboxylation were the main pathways in hydrothermal carbonization of the natural Scenedesmus, and the demethylation pathway was negligible. Oxygen was removed in the form of H2O and CO2. The degree of carbonization was enhanced and hydrochars had the potential to be applied to solid fuels. Since hydrochars contained a large amount of ash, its calorific value was in the range of 8.43-9.67 MJ/kg. Hence, the pretreatment of deashing was a necessary process. The hydrothermal carbonization treatment effectively improved the pore structure of hydrochars, and the absorption-desorption capacity of hydrochars was obviously enhanced. Compared with natural Scenedesmus (4.36 m2/g), the specific surface area of hydrochars was in the range of 28.7-35.26 m2/g. The natural Scenedesmus had a dense block-like without pores or pathways. However, the morphologies of hydrochars changed significantly. The fragmentation and porosity of hydrochars increased, which attributed to the release of volatile matter during hydrothermal carbonization process and chemical bond decomposition of feedstock. The thermogravimetric analysis experiments were carried out to reveal the pyrolysis characteristics of hydrochars. It was found that the weight loss peak at 300℃ gradually disappeared with the increased of hydrothermal temperature. This was owing to the degree of natural Scenedesmus increased and the volatile matter content decreased. When the hydrothermal temperature was higher than 220℃, the maximum weight loss rate peak moved to the high temperature zone. The pyrolysis kinetics results showed that the thermal stability of hydrochars increased with the increase of hydrothermal temperature. The hydrochars were more hydrophobic than that of the natural Scenedesmus. The research results provide a theoretical reference for the resource utilization of natural microalgae.

  • 205.
    Liu, Huihui
    et al.
    State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province, China.
    Chen, Yingquan
    State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province, China.
    Yang, Haiping
    State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province, China.
    Gentili, Francesco G.
    SLU.
    Söderlind, Ulf
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Wang, Xianhua
    State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province, China.
    Zhang, Wennan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Chen, Hanping
    State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province, China.
    Conversion of high-ash microalgae through hydrothermal liquefaction2020In: Sustainable Energy & Fuels, E-ISSN 2398-4902, Vol. 4, no 6, p. 2782-2791Article in journal (Refereed)
    Abstract [en]

    Natural microalgae (NM,Scenedesmus) cultivated by utilization of exhaust gas from a municipal solid waste combustion power plant were used for the biofuel production through hydrothermal liquefaction (HTL). The high-ash NM underwent acid-washing to obtain deashing microalgae (DA). HTL experiments were carried out at different temperatures from 260 °C to 340 °C with NM and DA. Products derived from NM and DA were examined by various techniques in order to identify the influence of the ash on the hydrothermal decomposition behavior. The results show that the ash inhibits the transformation of microalgae. The bio-oil yield including heavy oil and light oil is in the range of 17.59-22.09% for NM and 24.30-31.14% for DA, respectively. Calcium carbonate in the ash promotes deamination, resulting in an increase in the relative content of ketones in the NM-derived light oil. The concentration of NH4+in the aqueous phase derived from NM is in the range of 1373-1860 mg L−1, and PO43−is undetected due to the precipitation reaction between phosphorus and calcium ions. The HHV values of NM-derived hydrochars are low, ranging from 8.83 MJ kg−1to 9.88 MJ kg−1, compared with those of DA-derived hydrochars,. For natural microalgae, the deashing pretreatment before HTL is of great significance for improving the biocrude yield and quality, as well as the biomass conversion efficiency, nitrogen utilization and the hydrochar quality.

  • 206.
    Liu, Huihui
    et al.
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China.
    Chen, Yingquan
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China.
    Yang, Haiping
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China.
    Gentili, Francesco G.
    Swedish Univ Agr Sci, Umeå.
    Söderlind, Ulf
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Wang, Xianhua
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China.
    Zhang, Wennan
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Chemical Engineering.
    Chen, Hanping
    Huazhong Univ Sci & Technol, Wuhan, Hubei, Peoples R China.
    Hydrothermal carbonization of natural microalgae containing a high ash content2019In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 249, p. 441-448Article in journal (Refereed)
    Abstract [en]

    The potential to convert natural microalgae (Scenedesmus) into solid fuels by hydrothermal carbonization (HTC) was evaluated. The deashing microalgae (DA) were obtained by acid-washing natural microalgae (NM) with HCl. The deashing efficiency was high from 44.66% for NM to 14.45% for DA. HTC carried out at temperature in the range from 180 to 260 degrees C with this two types feedstock (i.e. NM and DA). The results showed that DA-derived hydrochars had good physicochemical and fuel properties compared with that of NM-derived hydrochars. HTC process of DA was mainly based on polymerization, and the hydrolysis process was short. The hydrochars obtained from DA at 220 degrees C (HC-D220) had the highest value of 51.86% with a carbon content and fixed carbon content 1.15 and 1.33 times, respectively, greater than that of DA. The high heating value (HHV) of HC-D220 reached 26.64 MJ/kg which is equivalent to medium-high calorific coal. The thermogravimetric analysis (TG) demonstrated that the hydrochars derived from DA have good combustion properties with stable at high temperature zones. They can easily mix with coal or replace coal in combustion application. The results of this study revealed that natural microalgae can be utilized by hydrothermal carbonization to generate renewable fuel resources.

  • 207.
    Liu, Xiaolin
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Balogun, Kazeem
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    BIOMASS PRODUCTION FOR ENERGY IN DEVELOPING COUNTRY: Case Study: CHINA and NIGERIA2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Most developing countries of the world still uses biomass for domestic energy, this is mostly used in the rural areas and using our case study which is Nigeria and China. We have been able to establish the potential of biomass production energy use by looking at calorific values of some biomass such As-harvested wood, Dry wood, Straw Miscanthus Coal  which was discussed on the introduction part of this thesis.

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    Biomass production for energy in developing country
  • 208.
    Lofstedt, Joakim
    et al.
    Renfuel AB, Sturegatan 38, S-11436 Stockholm, Sweden..
    Dahlstrand, Christian
    Renfuel AB, Sturegatan 38, S-11436 Stockholm, Sweden..
    Orebom, Alexander
    Renfuel AB, Sturegatan 38, S-11436 Stockholm, Sweden..
    Meuzelaar, Gerrit
    Renfuel AB, Sturegatan 38, S-11436 Stockholm, Sweden..
    Sawadjoon, Supaporn
    Renfuel AB, Sturegatan 38, S-11436 Stockholm, Sweden..
    Galkin, Maxim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Agback, Peter
    Swedish Univ Agr Sci, Dept Chem, Uppsala BioCtr, POB 7015, S-75007 Uppsala, Sweden..
    Wimby, Martin
    Valmet AB, Regnbagsgatan 6, S-41755 Gothenburg, Sweden..
    Corresa, Elena
    Univ Politecn Valencia, Inst Tecnol Quim UPV CSIC, Ave Tarongers S-N, E-46022 Valencia, Spain..
    Mathieu, Yannick
    Univ Politecn Valencia, Inst Tecnol Quim UPV CSIC, Ave Tarongers S-N, E-46022 Valencia, Spain..
    Sauvanaud, Laurent
    Univ Politecn Valencia, Inst Tecnol Quim UPV CSIC, Ave Tarongers S-N, E-46022 Valencia, Spain..
    Eriksson, Sören
    Preem AB, Warfvinges Vag 45, S-11251 Stockholm, Sweden..
    Corma, Avelino
    Univ Politecn Valencia, Inst Tecnol Quim UPV CSIC, Ave Tarongers S-N, E-46022 Valencia, Spain..
    Samec, Joseph S. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Renfuel AB, Sturegatan 38, S-11436 Stockholm, Sweden..
    Green Diesel from Kraft Lignin in Three Steps2016In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 9, no 12, p. 1392-1396Article in journal (Refereed)
    Abstract [en]

    Precipitated kraft lignin from black liquor was converted into green diesel in three steps. A mild Ni-catalyzed transfer hydrogenation/hydrogenolysis using 2-propanol generated a lignin residue in which the ethers, carbonyls, and olefins were reduced. An organocatalyzed esterification of the lignin residue with an insitu prepared tall oil fatty acid anhydride gave an esterified lignin residue that was soluble in light gas oil. The esterified lignin residue was coprocessed with light gas oil in a continous hydrotreater to produce a green diesel. This approach will enable the development of new techniques to process commercial lignin in existing oil refinery infrastructures to standardized transportation fuels in the future.

  • 209.
    Lopes, Merwyn
    KTH, School of Industrial Engineering and Management (ITM), Industrial Ecology.
    Feasibility study: Biogas in Sonderborg2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

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

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    merwyn_lopes
  • 210.
    Lorenzi, Guido
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. IN+, Instituto Superior Técnico, Universidade de Lisboa, Avenida Rovisco Pais 1, Lisbon, 1049-001, Portugal.
    Gorgoroni, M.
    Silva, C.
    Santarelli, Massimo
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology. Department of Energy (DENERG), Politecnico di Torino, Corso Duca Degli Abruzzi, 24, Turin, 10129, Italy.
    Life cycle assessment of biogas upgrading routes2019In: Innovative Solutions for Energy Transitions, Elsevier, 2019, Vol. 158, p. 2012-2018Conference paper (Refereed)
    Abstract [en]

    The upgrading of biogas to biomethane, by removing contaminants and carbon dioxide, is a treatment that allows this gaseous fuel to reach the specifications suitable for the injection in the natural gas grid and the use as vehicle fuel. This pathway enables the conversion of wet biomass into a perfect substitute of natural gas. Biogas upgrading is usually performed through CO2 removal and the most diffused method is water scrubbing. However, the embedded CO2 could be directly recycled into methane through a high-temperature co-electrolysis process followed by a methanation step, thus increasing the yield of biomethane for the same biogas inlet. In this paper the environmental impacts of two routes for biomethane production are compared in the framework of the Life Cycle Assessment (LCA) methodology. A sensitivity analysis for different shares of renewable content in electricity has been carried out. The results show that the large need for electrical energy penalizes the electrolytic process for renewable contents of the electricity which are not close to 100%.

  • 211.
    Lu, H D
    et al.
    Huaiyin Institute of Technology, China.
    Yadav, V
    Northwest A&F University, China.
    Zhong, M Y
    Huaiyin Institute of Technology, China.
    Bilal, M
    Huaiyin Institute of Technology, China.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Iqbal, M N H
    School of Engineering and Sciences, Mexico.
    Bioengineered microbial platforms for biomass-derived biofuel production: A review2022In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 288Article in journal (Refereed)
    Abstract [en]

    Global warming issues, rapid fossil fuel diminution, and increasing worldwide energy demands have diverted accelerated attention in finding alternate sources of biofuels and energy to combat the energy crisis. Bioconversion of lignocellulosic biomass has emerged as a prodigious way to produce various renewable biofuels such as biodiesel, bioethanol, biogas, and biohydrogen. Ideal microbial hosts for biofuel synthesis should be capable of using high substrate quantity, tolerance to inhibiting substances and end-products, fast sugar transportation, and amplified metabolic fluxes to yielding enhanced fermentative bioproduct. Genetic manipulation and microbes' metabolic engineering are fascinating strategies for the economical production of next-generation biofuel from lignocellulosic feedstocks. Metabolic engineering is a rapidly developing approach to construct robust biofuelproducing microbial hosts and an important component for future bioeconomy. This approach has been widely adopted in the last decade for redirecting and revamping the biosynthetic pathways to obtain a high titer of target products. Biotechnologists and metabolic scientists have produced a wide variety of new products with industrial relevance through metabolic pathway engineering or optimizing native metabolic pathways. This review focuses on exploiting metabolically engineered microbes as promising cell factories for the enhanced production of advanced biofuels.

  • 212.
    Lu, Yu-Chiao
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Process.
    Yang, Hanmin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Process.
    Karasev, Andrey
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Process.
    Wang, Chuan
    Swerim AB, Proc Met, SE-97125 Luleå, Sweden..
    Jönsson, Pär
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Process.
    Applications of Hydrochar and Charcoal in the Iron and Steelmaking Industry-Part 1: Characterization of Carbonaceous Materials2022In: Sustainability, E-ISSN 2071-1050, Vol. 14, no 15, article id 9488Article in journal (Refereed)
    Abstract [en]

    The iron and steelmaking industry faces the dilemma of the need to decrease their greenhouse gas emissions to align with decarbonization goals, while at the same time fulfill the increasing steel demand from the growing population. Replacing fossil coal and coke with biomass-based carbon materials reduces the net carbon dioxide emissions. However, there is currently a shortage of charcoal to fully cover the demand from the iron and steelmaking industry to achieve the emission-reduction goals. Moreover, the transportation and energy sectors can compete for biofuel usage in the next few decades. Simultaneously, our society faces challenges of accumulation of wastes, especially wet organic wastes that are currently not reused and recycled to their full potentials. Here, hydrothermal carbonization is a technology which can convert organic feedstocks with high moisture contents to solid fuels (hydrochar, one type of biochar) as an alternative renewable carbon material. This work studied the differences between a hydrochar, produced from lemon peels (Lemon Hydrochar), and two types of charcoals (with and without densification) and an Anthracite coal. Characterizations such as chemical and ash compositions, thermogravimetric analyses in nitrogen and carbon dioxide atmospheres, scanning electron microscope analyses of carbon surface morphologies, and pyrolysis up to 1200 degrees C were performed. The main conclusions from this study are the following: (1) hydrochar has a lower thermal stability and a higher reactivity compared to charcoal and Anthracite; (2) densification resulted in a reduction of the moisture pickup and CO2 reactivity of charcoal; (3) pyrolysis of Lemon Hydrochar resulted in the formation of a large amount of tar (17 wt%) and gas (39 wt%), leading to its low fixed carbon content (27 wt%); (4) a pyrolyzed hydrochar (up to 1200 degrees C) has a comparable higher heating value to those of charcoal and Anthracite, but its phosphorous, ash, and alkalis contents increased significantly; (5) based on the preliminary assessment, hydrochar should be blended with charcoal or Anthracite, or be upgraded through slow pyrolysis to fulfill the basic functions of carbon in the high-temperature metallurgical processes.

  • 213.
    Lund, Johanna
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Gunnarsson, Carina
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Fischer, Erik
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Chemistry and Materials.
    Sundberg, Martin
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Tersmeden, Marianne
    RISE - Research Institutes of Sweden (2017-2019), Bioscience and Materials, Agrifood and Bioscience.
    Outnyttjat ensilage till förnybar energi2018Report (Other academic)
    Abstract [en]

    There are large amounts of unutilized silage from agriculture and from municipalities that harvest meadows and grasslands. This biomass is a disposal problem and a cost. At the same time, there are biogas plants which have an increased demand for substrates that do not compete with the production of feed and food. Unutilized silage can be an excellent biogas substrate provided it is effectively pretreated. This study is conducted as a case study of Jordberga Biogas plant in Skåne (in the south of Sweden), although the results of the project are applicable to other regions in Sweden where unutilized silage exists. The project aim was to study a 20 % replacement

    of today’s crop-based substrates in Jordberga biogas plant with unutilized silage from agriculture and municipalities. The project has been conducted by RISE Agrifood and Bioscience in collaboration with the German Biomass Research Center (Deutsches Biomasseforschungszentrum, DBFZ), Gasum, County Administrative Board of Skåne and Fogda Farm.

    The project was divided into three parts. In the first part the amounts of different types of unutilized silage was estimated, from arable land and forage areas at municipalities and County Administrative Boards, for the area around the Gasum Biogas plant in Jordberga, and for Sweden in total. In a second part the adequate technique for pretreatment was identified and tested in practical trials on different types of unutilized silage. In the third part cost calculations were done for the disintegration of the unutilized silage.

    The study showed that the largest potential for unutilized silage is from forage production. The area of meadows is much less with much lower yield. An assumption was made that 5% of the total amount of unutilized silage bales are available for biogas production. Project calculations showed that 35% of these must be used to substitute 20% of the crop based substrates at Jordberga. Depending on the quality and biogas yield, 12-23 ton DM is needed per day.

    Based on earlier studies and experiences from the project group, three machines were chosen for the practical tests to disintegrate silage bales; Rot Grind, RS CutMaster and I-GRIND. Roto Grind and I-GRIND used hammermill technique whereas RS CutMaster

    used knife rotors for disintegration. All three machines managed to disintegrate silage bales with DM-content varying from 40-70% DM. The particle length after disintegration was analyzed and a visual estimation of the effect on particle structure was made. Particle size after disintegration was the same for Roto Grind and RS CutMaster whereas it was considerable longer for I-GRIND. Disintegration worked better on silage with lower DM content regarding both particle size and structure for all tested machines.

    Based on the test results RS CutMaster had higher total disintegration costs compared with Roto Grind and I-GRIND. The differences in costs was mainly due to lower measured capacity of RS CutMaster, and higher depreciation and maintenance costs of both RS CutMaster and I-GRIND. To lower the costs to same level as Roto Grind and I-GRIND, RS CutMaster would need approximately 40% higher capacity than measured in the tests.

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  • 214.
    Lundqvist, Petter
    Luleå University of Technology, Department of Engineering Sciences and Mathematics.
    Catalytic Hydrothermal Liquefaction of Waste Sludge: A Pre-study with Model Compounds2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The use and research of renewable fuels has become more important due to the connection between climate changes and the use of fossil fuels. With risks of decline in petroleum production derived from fossil fuels due to limitation of resources in the future, the renewable fuels are even more important in the transport sector.

    Research regarding gasification of biomass to create a syngas that can be upgraded to a biodiesel for cars is one of the approaches. By gasifying black liquor, it is possible to create a 100 % green fuel diesel. However, as this black liquor might be in limited quantities the idea to create a synthetic black liquor was sparked. The pulp industry where the black liquor originated from also has quantities of wastewater, containing a biomass sludge. Otherwise containing water in so large quantities that it is not possible to combust it without ending up with a negative energy output.

    One of the paths could be to recover the biomass from the sludge and convert it to a liquid similar to black liquor. Catalytic hydrothermal liquefaction has been recognized as a potential method. While biocrude is usually the target in hydrothermal liquefaction for direct upgrade to biofuel, the aqueous product could prove to be used for the gasification process. This would create a combined liquefaction-gasification process.

    Using model compounds possibly existing in the waste sludge, hydrothermal liquefaction was performed at different temperatures, together with varied alkali loads (K2CO3) and water the content to see how the different compounds reacted. Model compounds included cellulose and lignin as major compounds.

    Although the temperature was increased from 240 °C to 340 ° the lignin conversion was lower at 340 °C than at 240 °C. Re-polymerization took place and around 40 % of resulted in solid residue, while the remaining 60 % was partially converted to aqueous phase, oil phase or gas in the process. By not performing the hydrothermal liquefaction it is however possible to dissolve Kraft lignin directly in water and alkali.

    Cellulose showed an almost full conversion at 290 °C with similar results at 340 °C, with 4 – 5 % remaining as solid. At the higher temperature more gas was produced, which is not optimal for this process where liquid product is wanted. This suggest that 290 °C is enough for cellulose conversion in this process. Using an alkali load of 0.3 times the cellulose mass in the solution the final aqueous product contained about 26 % alkali, which is similar to black liquor. Increase the alkali to 0.9 times however increased the sought aqueous product, in both terms of energy and carbon content.

    Fiber sludge from a pulp mill, containing mainly cellulose, could therefore most likely be converted to a liquid product that is similar to black liquor for further upgrade

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  • 215.
    Lönnqvist, Tomas
    et al.
    KTH, Energi och klimatstudier, ECS.
    Olsson, Jesper
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center. MDH.
    Espinosa, Cecilia
    Center for Promotion of Sustainable Technology (CPTS).
    Birbuet, Juan Cristóbal
    Center for Promotion of Sustainable Technology (CPTS).
    Silveira, Semida
    KTH.
    Dahlquist, Erik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Thorin, Eva
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Persson, Per-Erik
    VAFAB Miljö AB.
    Lindblom, Sandra
    VAFAB Miljö AB.
    Khatiwada, Dilip
    KTH.
    The potential for waste to biogas in La Paz and El Alto in Bolivia2013In: 1st International Water Association Conference on HolisticSludge Management, 2013, Västerås Sweden, 2013Conference paper (Refereed)
    Abstract [en]

    In the cities of La Paz and El Alto, 573 tons of organic material are disposed in landfills every day. These residues can be used to produce biogas and recycle nutrients, thus alleviating environmental impacts related to waste management. Technical solutions are evaluated through a multicriteria analysis with the purpose of defining a strategy for implementing waste-to-biogas in the two cities. As a result, the development for waste-to-biogas-system is defined in three steps. Step 1 consists of an active extraction system of landfill gas in the already existing landfills. Step 2 implies the establishment of a dry-digestion biogas facility based on present waste collection practices, that is, not segregated waste. Step 3 consists of a biogas plant using dry digestion for processing source segregated bio-waste. The economic feasibility of these three steps is evaluated. Despite prevailing fossil fuels subsidies in the country, implementing waste-to-biogas turn out feasible in the country provided the digestate is commercialized as bio-fertilizer or erosion control material and additional services such as waste collection and deposition are computed in the total economy of the biogas production plant.

  • 216.
    Lönnqvist, Tomas
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Silveira, Semida
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Enhancing the biogas potential from residues and energy crops in Sweden2010Conference paper (Other academic)
    Abstract [en]

    Gas has played a marginal role in the Swedish energy system not only because Sweden lacks fossil gas resources but also due to the lack of specific policies to develop the segment. This contrasts with the present situation in many other European countries where gas grids and markets are well developed. More recently, changing demand patterns in the transport sector and stringent environmental policies have triggered the development of biogas and provided a strong incentive for the development of infrastructure for biomethane in many Swedish towns. On-going initiatives often combine public and private efforts mainly at the municipal level. They build upon new opportunities in the transport sector and, thus, the biogas is upgraded to biomethane to fulfil the standard requirements of vehicle engines. However, biomethane production and infrastructural efforts have not always been in phase with the rapid expansion of the vehicle fleet.Only a small part of the practical production potential for biogas has been realized in Sweden so far. There is considerable potential for further expansion based on agricultural, urban and industrial residues, but also energy crops. However, assessments regarding the potential for energy crops in Sweden are rather divergent. This paper provides a comparison between different Swedish assessments and also European ones and further discusses the practical potential for biogas generation in Sweden. Immediate opportunities for biogas generation are identified. The study results from a collaboration between the division of Energy and Climate Studies at KTH and Fortum Värme.

  • 217.
    Ma, Charlie
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Aspects of Ash Transformations in Pressurised Entrained-Flow Gasification of Woody Biomass: Pilot-scale studies2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Pressurised entrained-flow gasification (PEFG) of woody biomass has the potential to produce high purity syngas for the production of vital chemicals, e.g., biofuels. However, ash-related issues such as reactor blockages and refractory corrosion need to be addressed before this potential can be realised from a technical perspective. These undesirable consequences can be brought about by slag formation involving inorganic ash-forming elements and the chemical transformations that they undergo during fuel conversion. The objective of this study was to elucidate the ash transformations of the major ash-forming elements and the slag formation process. A pilot-scale PEFG reactor was used as the basis of the study, gasifying different woody biomass-based fuels including wood, bark, and a bark/peat mixture. Different ash fractions were collected and chemically analysed. Reactor slags had elemental distributions differing from that of the fuel ash, indicating the occurrence of fractionation of ash material during fuel conversion. Fly ash particles from a bark campaign were also heterogeneous with particles exhibiting differing compositions and physical properties; e.g., molten and crystalline formations. Si was consistently enriched in the reactor slags compared to other major ash-forming elements, while analyses of other ash fractions indicated that K was likely volatilised to a significant extent. In terms of slag behaviour, near-wall temperatures of approximately 1050-1200 °C inside the reactor were insufficient to form flowing ash slag for continuous extraction of ash material during firing the woody biomass fuels alone. However, fuel blending of a bark fuel with a silica-rich peat changed the chemical composition of the reactor slags and bulk slag flow behaviour was evident. Thermochemical equilibrium calculations supported the importance of Si in melt formation and in lowering solidus and liquidus temperatures of Ca-rich slag compositions that are typical from clean wood and bark. Viscosity estimations also showed the impact that solids have upon slag flow behaviour and corresponded qualitatively to the experimental observations. Corrosion of reactor refractory was observed. The mullite-based refractory of the reactor formed a slag with the fuel ash slag, which caused the former to flux away. Reactor blockages were also resultant because of the high viscosity of this slag near the outlet.  A preliminary study into the corrosion of different refractories was also carried out, based on firing a bark/peat mixture.  Alumina-rich refractories consisting of corundum, hibonite, mullite, and andalusite tended to form anorthite and exhibited varying degrees of degradation. Infiltration of slag was evident for all the samples and was a severe mode of degradation for some refractories. For fused-cast periclase and spinel-based refractories, slag infiltration was limited to voids and no extensive signs of refractory dissolution were found. This is also supported by a thermochemical equilibrium calculations mimicking slag infiltration that incorporated viscosity estimations. The findings from this thesis contribute towards the development of woody biomass PEFG by highlighting issues concerning ash fractionation, slag behaviours and ash\slash refractory interaction that should be investigated further.

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  • 218.
    Ma, Charlie
    et al.
    Energy Engineering, Division of Energy Science, Luleå University of Technology, Luleå, Sweden.
    Carlborg, Markus
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Hedman, Henry
    Wennebro, Jonas
    Weiland, Fredrik
    Wiinikka, Henrik
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Öhman, Marcus
    Ash Formation in Pilot-Scale Pressurized Entrained-Flow Gasification of Bark and a Bark/Peat Mixture2016In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 30, no 12, p. 10543-10554Article in journal (Refereed)
    Abstract [en]

    Pressurized entrained-flow gasification (PEFG) of bark and a bark/peat mixture (BPM) was carried out in a pilot-scale reactor (600 kWth, 7 bar(a)) with the objective of studying ash transformations and behaviors. The bark fuel produced a sintered but nonflowing reactor slag, while the BPM fuel produced a flowing reactor slag. Si was enriched within these slags compared to their original fuel ash compositions, especially in the bark campaign, which indicated extensive ash matter fractionation. Thermodynamically, the Si contents largely accounted for the differences in the predicted solidus/liquidus temperatures and melt formations of the reactor slags. Suspension flow viscosity estimations were in qualitative agreement with observations and highlighted potential difficulties in controlling slag flow. Quench solids from the bark campaign were mainly composed of heterogeneous particles resembling reactor fly ash particles, while those from the BPM campaign were flowing slags with likely chemical interactions with the wall refractory. Quench effluents and raw syngas particles were dominated by elevated levels of K that, along with other chemical aspects, indicated KOH(g) and/or K(g) were likely formed during PEFG. Overall, the results provide information toward development of woody biomass PEFG and indicate that detailed understanding of the ash matter fractionation behavior is essential.

  • 219. Ma, Charlie
    et al.
    Weiland, Fredrik
    Hedman, Henry
    Boström, Dan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Ohman, Marcus
    Characterization of Reactor Ash Deposits from Pilot-Scale Pressurized Entrained-Flow Gasification of Woody Biomass2013In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 27, no 11, p. 6801-6814Article in journal (Refereed)
    Abstract [en]

    Pressurized entrained-flow gasification of renewable forest residues has the potential to produce high-quality syngas suitable for the synthesis of transport fuels and chemicals. The ash transformation behavior during gasification is critical to the overall production process and necessitates a level of understanding to implement appropriate control measures. Toward this end, ash deposits were collected from inside the reactor of a pilot-scale O-2-blown pressurized entrained-flow gasifier firing stem wood, bark, and pulp mill debarking residue (PMDR) in separate campaigns. These deposits were characterized with environmental scanning electron microscopy equipped with energy-dispersive X-ray spectrometry and X-ray diffractometry. The stem wood deposit contained high levels of calcium and was comparatively insubstantial. The bark and PMDR fuels contained contaminant sand and feldspar particles that were subsequently evident in each respective deposit. The bark deposit consisted of lightly sintered ash aggregates comprising presumably a silicate melt that enveloped particles of quartz and, to a lesser degree, feldspars. Discontinuous layers likely to be composed of alkaline-earth metal silicates were found upon the aggregate peripheries. The PMDR deposit consisted of a continuous slag that contained quartz and feldspar particles dispersed within a silicate melt. Significant levels of alkaline-earth and alkali metals constituted the silicate melts of both the bark and PMDR deposits. Overall, the results suggest that fuel contaminants (i.e., quartz and feldspars) play a significant role in the slag formation process during pressurized entrained-flow gasification of these woody biomasses.

  • 220. Ma, Chunyan
    et al.
    Wang, Nan
    Chen, Yifeng
    Khokarale, Santosh Govind
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Bui, Thai Q.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Weiland, Fredrik
    Lestander, Torbjörn A.
    Rudolfsson, Magnus
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Åbo Akademi University, Industrial Chemistry & Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo-Turku, Finland .
    Ji, Xiaoyan
    Towards negative carbon emissions: Carbon capture in bio-syngas from gasification by aqueous pentaethylenehexamine2020In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 279, article id 115877Article in journal (Refereed)
    Abstract [en]

    In this work, an aqueous pentaethylenehexamine (PEHA) solution was studied for CO2 removal from bio-syngas for the first time. Firstly, pure CO2 absorption in aqueous PEHA solution under different conditions was conducted, and 20 wt% PEHA solution was identified as the best option. Secondly, the capture of CO2 was tested with synthetic syngas from a gas cylinder, and the species other than CO2 showed a negligible impact on CO2 removal. Finally, to evaluate the practical feasibility of using aqueous PEHA solution on the downstream CO2 capture, the pilot experiments of gasification with boreal forest-based biomasses were designed to provide real syngas with a realistic distribution in composition for further testing. The results showed that the operating conditions and the type of feedstocks affected the distribution in the bio-syngas composition. Among these feedstocks, at the optimal oxygen supply, using spruce needles generated the highest yields of CO and H2 and, meanwhile, gave rise to similar yields of other gases such as CO2, CH4, etc. The influence of the species other than CO2 for CO2 removal was negligible. Additionally, aqueous PEHA solution was tested as a biomass pretreatment agent, showing that no significant changes could be identified by the ultimate analysis (except for increased nitrogen content), but the yields of CO were affected negatively. On the other hand, when using the pretreated biomass by the aqueous PEHA solution, the NH3 concentration in bio-syngas reached to the highest (4000 parts per million), which slightly affected the CO2 absorption capacity and initial absorption rate of 20 wt% PEHA solution in a positive way.

  • 221.
    Mabecua, Fastudo Jorge
    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.
    Lucas, C.
    Department of Chemical Engineering, Eduardo Mondlane University, Maputo, Mozambique.
    Klintenberg, Patrik
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Agro-waste, a solution for rural electrification?: Assessing biomethane potential of agro-waste in inhambane province, southern mozambique2021In: Water, E-ISSN 2073-4441, Vol. 13, no 7, article id 939Article in journal (Refereed)
    Abstract [en]

    In this study, we investigated the biomethane potential of cassava peels from the four most common varieties of cassava grown in Inhambane Province in Mozambique, Chinhembue, Cussi, Cizangara and Nhassumbi. Agro-wastes from coconut wood and jambolan wood processing were also analyzed to give a complete analysis of the most significant sources of agro-waste in the province. The macromolecular composition (carbohydrates, lipids and proteins) was determined and used to calculate the theoretical maximum biochemical methane potential (BMP). The results show that cassava fiber and cassava peel, which are considered to be waste, are viable resources for biomethane production. Further, the results show that cassava fiber and cassava peel have a higher biomethane potential compared with sawdust, and are therefore more suitable for biomethane production. A study to investigate the effect of toxic cyanogenic glycosides and lignin on cassava peels, using pre-treatment techniques to enhance biogas yield, should be carried out. An estimate of how much electricity can be generated based on the availability of agro-waste (cassava residues) and the amount of biomethane produced in our laboratory experiment was carried out. The amount of electricity that can be produced is enough to provide a valuable contribution to the production process in small and medium sized enterprises (SMEs) and in the cassava industry, or some other use in the rural setting. 

  • 222.
    Mander, Sarah
    et al.
    Univ Manchester, Tyndall Ctr Climate Change Res, Manchester M13 4PL, Lancs, England..
    Anderson, Kevin
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Natural Resources and Sustainable Development. Univ Manchester, Tyndall Ctr Climate Change Res, Manchester M13 4PL, Lancs, England.
    Larkin, Alice
    Univ Manchester, Tyndall Ctr Climate Change Res, Manchester M13 4PL, Lancs, England..
    Gough, Clair
    Univ Manchester, Tyndall Ctr Climate Change Res, Manchester M13 4PL, Lancs, England..
    Vaughan, Naomi
    Univ East Anglia, Tyndall Ctr Climate Change Res, Norwich NR4 7TJ, Norfolk, England..
    The role of bio-energy with carbon capture and storage in meeting the climate mitigation challenge: A whole system perspective2017In: 13Th International Conference on Greenhouse Gas Control Technologies, Ghgt-13 / [ed] Dixon, T Laloui, L Twinning, S, Elsevier, 2017, p. 6036-6043Conference paper (Refereed)
    Abstract [en]

    This paper explores the role and implications of bio-energy with carbon capture and storage (BECCS) for addressing the climate change mitigation challenge. Framed within the context of the latest emissions budgets, and their associated uncertainty, we present a summary of the contribution of BECCS within the Integrated Assessment Model (IAM) scenarios used by the climate change community. Within this discussion we seek to shed light on two important areas. Firstly, that BECCS is a central, but often hidden element of many of the modelling work that underpins climate policy from the global to the national scale. The second area we address are the assumptions for BECCS embedded within IAM models, and the wider system consequences of these implied levels of deployment. In light of these challenges, we question whether BECCS can deliver what is anticipated of it within existing climate change policy. (C) 2017 The Authors. Published by Elsevier Ltd.

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  • 223.
    Manzetti, Sergio
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Computational Biology and Bioinformatics. Fjordforsk AS, Nanofactory, Inst Sci & Technol, N-6894 Midtun, Vangsnes, Norway..
    Andersen, Otto
    Western Norway Res Inst, Postboks 163, N-6851 Sogndal, Norway..
    A molecular dynamics study of nanoparticle-formation from bioethanol-gasoline blend emissions2016In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 183, p. 55-63Article in journal (Refereed)
    Abstract [en]

    Aerosol components and nanoparticles deriving from fuel combustion represent a class of exhaust emissions with critical relevance to environmental studies. In particular, the formation of nanoparticles is an important theme for environmental assessments of new fuel blends. Here, a set of computer simulations is carried out to study the behaviour of acetaldehyde-phenanthrene nanoparticles in relation to the influences to the three major atmospheric components CO2, O-2, N-2. The results show that phenanthrene and acetaldehyde quickly generate nanoparticles with dimensions of 2-5 nm in vacuum. The formed particles are stable in atmospheric conditions and interestingly absorb CO2 from the atmosphere-gas simulations but not O-2 and N-2. The probability of absorption of CO2 in the formed nanoparticles results as 10-20-fold compared to N-2 and O-2. Furthermore, acetaldehyde appears to localize on the surface of the formed nanoparticles, and seemingly acts with the planar geometry of phenanthrene as a facilitator for CO2 absorption. The results provided show also the properties of formed nanoparticle with higher concentrations of acetaldehyde and lower of phenanthrene, where phenanthrene forms the core of the nanoparticle, while acetaldehyde interacts with the surface and subsurface area in making their chemistry hydrophilic with a dense aromatic core. The study is important for further assessing bioethanol and fuel blends, and also introduces a methodology for studying interactions of gases and particles at the molecular level, with macroscopic significance. The study reports on growth of nanoparticles by CO2 absorption, introduces a new issue for blending fuels, with implications towards pollution profiles.

  • 224. Marques, W. L.
    et al.
    Mans, R.
    Henderson, R. K.
    Marella, E. R.
    Horst, J. T.
    Hulster, E. D.
    Poolman, B.
    Daran, J. -M
    Pronk, J. T.
    Gombert, A. K.
    van Maris, Antonius J. A.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Industrial Biotechnology.
    Combined engineering of disaccharide transport and phosphorolysis for enhanced ATP yield from sucrose fermentation in Saccharomyces cerevisiae2018In: Metabolic engineering, ISSN 1096-7176, E-ISSN 1096-7184, Vol. 45, p. 121-133Article in journal (Refereed)
    Abstract [en]

    Anaerobic industrial fermentation processes do not require aeration and intensive mixing and the accompanying cost savings are beneficial for production of chemicals and fuels. However, the free-energy conservation of fermentative pathways is often insufficient for the production and export of the desired compounds and/or for cellular growth and maintenance. To increase free-energy conservation during fermentation of the industrially relevant disaccharide sucrose by Saccharomyces cerevisiae, we first replaced the native yeast α-glucosidases by an intracellular sucrose phosphorylase from Leuconostoc mesenteroides (LmSPase). Subsequently, we replaced the native proton-coupled sucrose uptake system by a putative sucrose facilitator from Phaseolus vulgaris (PvSUF1). The resulting strains grew anaerobically on sucrose at specific growth rates of 0.09 ± 0.02 h−1 (LmSPase) and 0.06 ± 0.01 h−1 (PvSUF1, LmSPase). Overexpression of the yeast PGM2 gene, which encodes phosphoglucomutase, increased anaerobic growth rates on sucrose of these strains to 0.23 ± 0.01 h−1 and 0.08 ± 0.00 h−1, respectively. Determination of the biomass yield in anaerobic sucrose-limited chemostat cultures was used to assess the free-energy conservation of the engineered strains. Replacement of intracellular hydrolase with a phosphorylase increased the biomass yield on sucrose by 31%. Additional replacement of the native proton-coupled sucrose uptake system by PvSUF1 increased the anaerobic biomass yield by a further 8%, resulting in an overall increase of 41%. By experimentally demonstrating an energetic benefit of the combined engineering of disaccharide uptake and cleavage, this study represents a first step towards anaerobic production of compounds whose metabolic pathways currently do not conserve sufficient free-energy.

  • 225.
    Martin, Carlos
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Department of Biotechnology, Inland Norway University of Applied Sciences, Hamar, Norway.
    Dixit, Pooja
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Momayez, Forough
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Jönsson, Leif J.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Hydrothermal Pretreatment of Lignocellulosic Feedstocks to Facilitate Biochemical Conversion2022In: Frontiers in Bioengineering and Biotechnology, E-ISSN 2296-4185, Vol. 10, article id 846592Article, review/survey (Refereed)
    Abstract [en]

    Biochemical conversion of lignocellulosic feedstocks to advanced biofuels and other bio-based commodities typically includes physical diminution, hydrothermal pretreatment, enzymatic saccharification, and valorization of sugars and hydrolysis lignin. This approach is also known as a sugar-platform process. The goal of the pretreatment is to facilitate the ensuing enzymatic saccharification of cellulose, which is otherwise impractical due to the recalcitrance of lignocellulosic feedstocks. This review focuses on hydrothermal pretreatment in comparison to alternative pretreatment methods, biomass properties and recalcitrance, reaction conditions and chemistry of hydrothermal pretreatment, methodology for characterization of pretreatment processes and pretreated materials, and how pretreatment affects subsequent process steps, such as enzymatic saccharification and microbial fermentation. Biochemical conversion based on hydrothermal pretreatment of lignocellulosic feedstocks has emerged as a technology of high industrial relevance and as an area where advances in modern industrial biotechnology become useful for reducing environmental problems and the dependence on fossil resources.

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  • 226.
    Martin, Michael
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Industrial Symbiosis in the Biofuel Industry: Quantification of the Environmental Performance and Identification of Synergies2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The production of biofuels has increased in recent years, to reduce the dependence on fossil fuels and mitigate climate change. However, current production practices are heavily criticized on their environmental sustainability. Life cycle assessments have therefore been used in policies and academic studies to assess the systems; with divergent results. In the coming years however, biofuel production practices must improve to meet strict environmental sustainability policies.

    The aims of the research presented in this thesis, are to explore and analyze concepts from industrial symbiosis (IS) to improve the efficiency and environmental performance of biofuel production and identify possible material and energy exchanges between biofuel producers and external industries.

    An exploration of potential material and energy exchanges resulted in a diverse set of possible exchanges. Many exchanges were identified between biofuel producers to make use of each other’s by-products. There is also large potential for exchanges with external industries, e.g. with the food, energy and chemical producing industries. As such, the biofuel industry and external industries have possibilities for potential collaboration and environmental performance improvements, though implementation of the exchanges may be influenced by many conditions.

    In order to analyze if concepts from IS can provide benefits to firms of an IS network, an approach was created which outlines how quantifications of IS networks can be produced using life cycle assessment literature for guidelines and methodological considerations. The approach offers methods for quantifying the environmental performance for firms of the IS network and an approach to distribute impacts and credits for the exchanges between firm, to test the assumed benefits for the firms of the IS network.

    Life cycle assessment, and the approach from this thesis, have been used to quantify the environmental performance of IS networks by building scenarios based on an example from an IS network of biofuel producers in Sweden. From the analyses, it has been found that exchanges of material and energy may offer environmental performance improvements for the IS network and for firms of the network. However, the results are dependent upon the methodological considerations of the assessments, including the reference system, functional unit and allocation methods, in addition to important processes such as the agricultural inputs for the system and energy systems employed.

    By using industrial symbiosis concepts, biofuel producers have possibilities to improve the environmental performance. This is done by making use of by-products and waste and diversifying their products, promoting a transition toward biorefinery systems and a bio-based economy for regional environmental sustainability.

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    Industrial Symbiosis in the Biofuel Industry: Quantification of the Environmental Performance and Identification of Synergies
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  • 227.
    Martin, Michael
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Using LCA to quantify the environmental performance of an industrial symbiosis network: Application in the Biofuels IndustryManuscript (preprint) (Other academic)
    Abstract [en]

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

  • 228.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Parsapour, Amin
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Upcycling wastes with biogas production:: An exergy and economic analysis2012In: Venice 2012: International Symposium on Energy from Biomass and Waste, Venice, Italy, 2012Conference paper (Other academic)
    Abstract [en]

    The massive consumption of finite resources creates high economical and environmental costs due to material dispersion and waste generation. In order to overcome this, by-products and wastes may be used, to avoid the use of virgin materials and benefit from the useful inherent energy of the material. By adding value to the material, economic and environmental performance can be improve, which is called upcycling. In this paper, an exergy and economic analysis of a biogas process is examined. In order to investigate if biogas production from wastes can upcycle materials, biogas production from a by-product from the brewing process is examined. From the analysis, the process is found to upcycle the by-product with an increase in exergy and economic benefit due to the generation of biomethane and biofertilizer. This analysis thus shows that by using by-products as such, the sustainability of the system may improve.

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    MMVenice2012
  • 229.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Who gets the benefits? An approach for assessing the environmental performance of industrial symbiosis2015In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 98, p. 263-271Article in journal (Refereed)
    Abstract [en]

    Industrial symbiosis networks are generally assumed to provide economic and environmental benefits for all firms involved, though few quantifications have been produced in the literature, and the methods for these quantifications have varied. This paper provides an approach to quantify the environmental performance of industrial symbiosis networks using guidance from the literature of life cycle assessment. Additionally, an approach to distribute credits due to exchanges for firms in the industrial symbiosis network is outlined. From the approach, influential methodological considerations used for the quantifications are discussed, including e.g. the production of reference systems, allocation methods, system boundaries and functional unit. The implications of such an approach may be beneficial for the industrial symbiosis community and provide information crucial for taxes, subsidies, business relations, expansion possibilities for the network, marketing and other issues related to the environmental performance of firms in the industrial symbiosis network.

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  • 230.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Fonseca, Jorge
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Quantifying the environmental performance of integrated bioethanol and biogas production2014In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 6, p. 109-116Article in journal (Refereed)
    Abstract [en]

    As the production of biofuels continues to expand worldwide, criticism about, e.g. the energy output versus input and the competition with food has been questioned. However, biofuels have the possibility to be optimized in order to improve the environmental performance. This could be accomplished through the use of concepts from industrial symbiosis. This paper provides a quantification of the environmental performance of industrial symbiosis in the biofuel industry through integration of biogas and ethanol processes using a life cycle approach. Results show that although increasing integration is assumed to produce environmental benefits, not all impact categories have achieved this and the results depend upon the allocation methods, energy system and assumptions chosen.

  • 231.
    Martin, Michael
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Svensson, Niclas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Fonseca, Jorge
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Who gets the benefits?: An approach for assessing the environmentalperformance of industrial symbiosis2012In: Greening of Industry Network: Support your future today! Turning environmental challenges into business opportunities, 2012Conference paper (Other academic)
    Abstract [en]

    It is generally assumed that industrial symbiosis creates economic and environmental benefits for all firmsinvolved, though only a few quantifications have been produced in the literature. An approach to quantifyenvironmental performance of industrial symbiosis using life cycle assessment has been provided,outlining the choice of functional unit, system boundaries, impact assessment and allocation as well as thedistribution of benefits among firms in the symbiotic activity. The implications of such an approach maybe beneficial for the industrial symbiosis and life cycle assessment communities and provide informationcrucial for taxes, subsidies, business relations, marketing and other issues related to the environmentalperformance of firms in the industrial symbiosis network.

  • 232.
    Martinez, Cristina A.
    et al.
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    Nohalez, Alicia
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    Parrilla, Inmaculada
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    Motas, Miguel
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    Roca, Jordi
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    Romero, Inmaculada
    CSIC, Spain.
    Garcia-Gonzalez, Diego L.
    CSIC, Spain.
    Cuello, Cristina
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    Rodriguez-Martinez, Heriberto
    Linköping University, Department of Clinical and Experimental Medicine, Division of Children's and Women's health. Linköping University, Faculty of Medicine and Health Sciences.
    Martinez, Emilio A.
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    Gil, Maria A.
    University of Murcia, Spain; IMIB Arrixaca, Spain.
    The overlaying oil type influences in vitro embryo production: differences in composition and compound transfer into incubation medium between oils2017In: Scientific Reports, E-ISSN 2045-2322, Vol. 7, article id 10505Article in journal (Refereed)
    Abstract [en]

    The oil overlay micro-drop system is widely used for cultures of mammalian gametes and embryos. We evaluated hereby the effects of two unaltered commercial oils-Sigma mineral oil (S-MO) and Nidoil paraffin oil (N-PO)-on in vitro embryo production (IVP) outcomes using a pig model. The results showed that while either oil apparently did not affect oocyte maturation and fertilization rates, S-MO negatively affected embryo cleavage rates, blastocyst formation rates, and, consequently, total blastocyst efficiency of the system. No differences in the oxidation state were found between the oils or culture media incubated under S-MO or N-PO. Although both oils slightly differed in elemental composition, there were no differences in the concentrations of elements between fresh media and media incubated under oils. By contrast, we demonstrated clear oil-type differences in both the composition of volatile organic compounds (VOC) and the transfer of some of these VOCs (straight-chain alkanes and pentanal and 1,3-diethyl benzene) to the culture medium, which could have influenced embryonic development.

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  • 233. Martinsson, J
    et al.
    Eriksson, A C
    Nielsen, I Elbaek
    Berg Malmborg, V
    Ahlberg, E
    Andersen, C
    Lindgren, R
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nyström, Robin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nordin, E Z
    Brune, W H
    Svenningsson, B
    Swietlicki, E
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Pagels, J H
    Impacts of Combustion Conditions and Photochemical Processing on the Light Absorption of Biomass Combustion Aerosol2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 24, p. 14663-14671Article in journal (Refereed)
    Abstract [en]

    The aim was to identify relationships between combustion conditions, particle characteristics, and optical properties of fresh and photochemically processed emissions from biomass combustion. The combustion conditions included nominal and high burn rate operation and individual combustion phases from a conventional wood stove. Low temperature pyrolysis upon fuel addition resulted in "tar-ball" type particles dominated by organic aerosol with an absorption Angstrom exponent (AAE) of 2.5-2.7 and estimated Brown Carbon contributions of 50-70% to absorption at the climate relevant aethalometer-wavelength (520 nm). High temperature combustion during the intermediate (flaming) phase was dominated by soot agglomerates with AAE 1.0-1.2 and 85-100% of absorption at 520 nm attributed to Black Carbon. Intense photochemical processing of high burn rate flaming combustion emissions in an oxidation flow reactor led to strong formation of Secondary Organic Aerosol, with no or weak absorption. PM1 mass emission factors (mg/kg) of fresh emissions were about an order of magnitude higher for low temperature pyrolysis compared to high temperature combustion. However, emission factors describing the absorption cross section emitted per kg of fuel consumed (m(2)/kg) were of similar magnitude at 520 nm for the diverse combustion conditions investigated in this study. These results provide a link between biomass combustion conditions, emitted particle types, and their optical properties in fresh and processed plumes which can be of value for source apportionment and balanced mitigation of biomass combustion emissions from a climate and health perspective.

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  • 234.
    Matsakas, Leonidas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Nitsos, Christos
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Vörös, Dimitrij
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Rova, Ulrika
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Christakopoulos, Paul
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    High-Titer Methane from Organosolv-Pretreated Spruce and Birch2017In: Energies, E-ISSN 1996-1073, Vol. 10, no 3, article id 263Article in journal (Refereed)
    Abstract [en]

    The negative impact of fossil fuels and the increased demand for renewable energy sources has led to the use of novel raw material sources. Lignocellulosic biomass could serve as a possible raw material for anaerobic digestion and production of biogas. This work is aimed at using forest biomass, both softwood (spruce) and hardwood (birch), as a raw material for anaerobic digestion. We examined the effect of different operational conditions for the organosolv pretreatment (ethanol content, duration of treatment, and addition of acid catalyst) on the methane yield. In addition, we investigated the effect of addition of cellulolytic enzymes during the digestion. We found that inclusion of an acid catalyst during organosolv pretreatment improved the yields from spruce, but it did not affect the yields from birch. Shorter duration of treatment was advantageous with both materials. Methane yields from spruce were higher with lower ethanol content whereas higher ethanol content was more beneficial for birch. The highest yields obtained were 185 mL CH4/g VS from spruce and 259.9 mL CH4/g VS from birch. Addition of cellulolytic enzymes improved these yields to 266.6 mL CH4/g VS and 284.2 mL CH4/g VS, respectively.

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  • 235. Matsakas, Leonidas
    et al.
    Sarkar, Omprakash
    Jansson, Stina
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Rova, Ulrika
    Christakopoulos, Paul
    A novel hybrid organosolv-steam explosion pretreatment and fractionation method delivers solids with superior thermophilic digestibility to methane2020In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 316, article id 123973Article in journal (Refereed)
    Abstract [en]

    Rising environmental concerns and the imminent depletion of fossil resources have sparked a strong interest towards the production of renewable energy such as biomethane. Inclusion of alternative feedstock’s such as lignocellulosic biomass could further expand the production of biomethane. The present study evaluated the potential of a novel hybrid organosolv-steam explosion fractionation for delivering highly digestible pretreated solids from birch and spruce woodchips. The highest methane production yield was 176.5 mLCH4 gVS−1 for spruce and 327.2 mL CH4 gVS−1 for birch. High methane production rates of 1.0–6.3 mL min−1 (spruce) and 6.0–35.5 mL min−1 (birch) were obtained, leading to a rapid digestion, with 92% of total methane from spruce being generated in 80 h and 95% of that from birch in 120 h. These results demonstrate the elevated potential of the novel method to fractionate spruce and birch biomass and deliver cellulose-rich pretreated solids with superior digestibility.

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  • 236.
    Mehariya, Sanjeet
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Goswami, Rahul Kumar
    Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, Rajasthan, India.
    Verma, Pradeep
    Bioprocess and Bioenergy Laboratory, Department of Microbiology, Central University of Rajasthan, Rajasthan, India.
    Lavecchia, Roberto
    Department of Chemical Engineering, Materials and Environment, Sapienza University of Rome, Rome, Italy.
    Zuorro, Antonio
    Department of Chemical Engineering, Materials and Environment, Sapienza University of Rome, Rome, Italy.
    Integrated approach for wastewater treatment and biofuel production in microalgae biorefineries2021In: Energies, E-ISSN 1996-1073, Vol. 14, no 8, article id 2282Article, review/survey (Refereed)
    Abstract [en]

    The increasing world population generates huge amounts of wastewater as well as large energy demand. Additionally, fossil fuel’s combustion for energy production causes the emission of greenhouse gases (GHG) and other pollutants. Therefore, there is a strong need to find alternative green approaches for wastewater treatment and energy production. Microalgae biorefineries could represent an effective strategy to mitigate the above problems. Microalgae biorefineries are a sustainable alternative to conventional wastewater treatment processes, as they potentially allow wastewater to be treated at lower costs and with lower energy consumption. Furthermore, they provide an effective means to recover valuable compounds for biofuel production or other applications. This review focuses on the current scenario and future prospects of microalgae biorefineries aimed at combining wastewater treatment with biofuel production. First, the different microalgal cultivation systems are examined, and their main characteristics and limitations are discussed. Then, the technologies available for converting the biomass produced during wastewater treatment into biofuel are critically analyzed. Finally, current challenges and research directions for biofuel production and wastewater treatment through this approach are outlined.

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  • 237.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    CFD approach to investigate fast pyrolysis by pre-heated steam, in a fluidized bed reactor2012Conference paper (Other academic)
  • 238.
    Mellin, Pelle
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Zhang, Qinglin
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Kantarelis, Efthymios
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Zhou, Chunguang
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Yang, Weihong
    KTH, School of Industrial Engineering and Management (ITM), Materials Science and Engineering, Energy and Furnace Technology.
    Accuracy and Potential Use of a Developed CFD-pyrolysis Model for Simulating Lab-scale Bio Oil Production2012In: The 20th EU BC&E Online Proceedings 2012, 2012, p. 953-959Conference paper (Other academic)
    Abstract [en]

    The paper describes development of a CFD¬pyrolysis model using an Eularian-Eularian framework with an implemented pyrolysis reaction model. The CFD¬pyrolysis model is used to simulate the bubbling fluidized bed reactor integrated in a new experimental fast pyrolysis process for bio oil production. The model is compared to experiments in aspect of outlet gas composition, temperature and bed height. Tar behavior and yield of bio oil are illustrated and a parametric study investigates impact of flow rate and temperature on bio oil yield. The results show a tolerable fit compared to measurements and reasonable tendencies in the parametric study.

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    2DO.8.2_20th_2012
  • 239.
    Menya, E.
    et al.
    Makerere Univ, Coll Engn Design Art & Technol, Dept Mech Engn, POB 7062, Kampala, Uganda.;Gulu Univ, Dept Biosyst Engn, POB 166, Gulu, Uganda..
    Olupot, P. W.
    Makerere Univ, Coll Engn Design Art & Technol, Dept Mech Engn, POB 7062, Kampala, Uganda..
    Storz, H.
    Thuenen Inst Agr Technol, Bundesallee 47, D-38116 Braunschweig, Germany..
    Lubwama, M.
    Makerere Univ, Coll Engn Design Art & Technol, Dept Mech Engn, POB 7062, Kampala, Uganda..
    Kiros, Yohannes
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Process Technology.
    Characterization and alkaline pretreatment of rice husk varieties in Uganda for potential utilization as precursors in the production of activated carbon and other value-added products2018In: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 81, p. 104-116Article in journal (Refereed)
    Abstract [en]

    In this study, 13 rice husk (RH) varieties from 4 agro-ecological zones in Uganda were characterized, NaOH-pretreated, and evaluated for their potential utilization as precursors for production of bio-oil, ash, char, and activated carbon for selected applications. RH varieties were characterized through particle size analysis, bulk density, proximate and ultimate analyses, specific surface area, pore volume, as well as lignocellulosic and inorganic compositions. Selected RH varieties were subsequently pretreated at NaOH concentrations of 1-4%w/v, using pretreatment ratios of 5 g RH: 40 mL NaOH. Properties varied among RH varieties, suiting them as feedstocks for different applications. Upland rice husk varieties are more suited precursors for production of bio-oil, and activated carbon due to their relatively lower ash content, higher specific surface area, as well as higher volatile matter and fixed carbon contents. Upland rice husks could as well be employed in the preparation of electrodes for electrochemical devices, due to their relatively higher specific surface area. A high ash content (21-32% dry basis) of lowland rice husks presents good prospects for their calcination, since larger amounts of rice husk ash could be obtained, and employed in different applications. Lowland rice husk varieties could also be more suited precursors for production of char for soil amendment, due to their relatively higher ash content, which subsequently increases their char yields. However, alkaline pretreatment of rice husks using 2-4%w/v NaOH can reduce the ash content by as much as 74-93%, depending on the rice husk variety, which paves way for utilizing rice husks with a high ash content in different applications. Aside from ash reduction, the enhanced specific surface area (1.2-1.7 m(2) g(-1)), volatile matter (68-79%db) and fixed carbon (19-24%db) contents of NaOH-pretreated rice husks suggests they are more suited feedstocks than when employed in their raw form, for production of bio-oil, as well as activated carbon.

  • 240.
    Mesfun, Sennai
    et al.
    RISE Res Inst Sweden, Stockholm, Sweden..
    Engvall, Klas
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering, Process Technology.
    Toffolo, Andrea
    Luleå Univ Technol, Dept Engn Sci & Math, Energy Sci Div, Luleå, Sweden..
    Electrolysis Assisted Biomass Gasification for Liquid Fuels Production2022In: Frontiers in Energy Research, E-ISSN 2296-598X, Vol. 10, article id 799553Article in journal (Refereed)
    Abstract [en]

    Gasification is a promising pathway for converting biomass residues into renewable transportation fuels and chemicals needed to comply with the ambitious Swedish environmental targets. The paper investigates the integration of a molten carbonate electrolysis cell (MCEC) in biofuel production pathway from sawmill byproducts, to improve the performance of gas cleaning and conditioning steps prior to the final conversion of syngas into liquid biofuels. The energy, material, and economic performance of process configurations with different gasification technologies are simulated and compared. The results provide relevant information to develop the engineering of gas-to-liquid transportation fuels utilizing renewable electricity. The MCEC replaces the water-gas shift step of a conventional syngas conditioning process and enables increased product throughput by as much as 15%-31%. Depending on the process configuration and steam-methane reforming technology, biofuels can be produced to the cost range 140-155 euro/MWh in the short-term.

  • 241.
    Michel, Julie
    et al.
    Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft, Delft, Netherlands; Univ Grenoble Alpes, CEA, LITEN, DEHT, Grenoble, France.
    Rivas-Arrieta, María J.
    Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft, Delft, Netherlands.
    Borén, Eleonora
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Simonin, Loïc
    Univ Grenoble Alpes, CEA, LITEN, DEHT, Grenoble, France.
    Kennedy, Maria
    Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft, Delft, Netherlands.
    Dupont, Capucine
    Department of Water Supply, Sanitation and Environmental Engineering, IHE Delft, Delft, Netherlands.
    Fate of biomass inorganic elements during hydrothermal carbonization: an experimental study on agro-food waste2023In: Biomass Conversion and Biorefinery, ISSN 2190-6815, E-ISSN 2190-6823Article in journal (Refereed)
    Abstract [en]

    The distribution of inorganic elements between solid and liquid phases during biomass hydrothermal carbonization (HTC) is a poorly investigated topic despite its importance for process optimization. To fill in this gap, the distribution of inorganic elements and their forms were determined for three agro-food waste feedstocks converted at HTC temperatures of 180, 220, and 260 °C in 12 h. Satisfactory balances were achieved, with values between 80 and 92% for C and N, and 80 and 110% for most inorganic elements. At 180 °C, over 90% of P, Mg, Ca, K, Na, and Mn were removed from hydrochars whatever feedstock. At higher temperatures, P, Mg, Ca, and Mn were partly reincorporated into hydrochars (between 7 and 53%), possibly due to the formation of insoluble precipitates, while K and Na remained in the liquid. On the opposite, some minor elements, Cu and Al, remained in the hydrochars, whatever temperature. Si showed different removal behaviors according to feedstock and temperature. These results show the possibility of optimizing the removal of inorganic elements from hydrochars using different temperatures.

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  • 242. Mohammadi, Marzieh
    et al.
    Shafiei, Marzieh
    Abdolmaleki, Amir
    Karimi, Keikhosro
    Mikkola, Jyri-Pekka
    Umeå University, Faculty of Science and Technology, Department of Chemistry. Industrial Chemistry & Reaction Engineering, Johan Gadolin Process Chemistry Centre, Åbo Akademi University, Åbo-Turku, Finland.
    Larsson, Christer
    A morpholinium ionic liquid for rice straw pretreatment to enhance ethanol production2019In: Industrial crops and products (Print), ISSN 0926-6690, E-ISSN 1872-633X, Vol. 139, article id 111494Article in journal (Refereed)
    Abstract [en]

    Rice straw was successfully pretreated with a novel and inexpensive morpholinium ionic liquid, 1-H-3-methylmorpholinium chloride ([HMMorph][Cl]). The influence of water (30, 40, 50% w/w) and dimethyl sulfoxide (DMSO) (10, 30% w/w), as co-solvents, pretreatment time (2, 3, 5 h), temperature (90, 105, 120 °C), solid loading (5, 6.7, 10% w/w), and straw particle size (<0.177, 0.177–0.841 mm, and 0.841–2 mm) were investigated for maximum ethanol production. The best results were obtained in 50% water, at 120 °C and 5% (w/w) solid loading for 5 h from 0.177 – 0.841 mm straw particles. The hydrolysis yield was increased from 33.2% to 70.1%, while ethanol production yield was improved from 21.9% to 64% of the theoretical maximum. The performance of the IL was comparable to 1-ethyl-3-methylimidazolium acetate. Simple synthesis process and dilute solution required for the pretreatment with [HMMorph][Cl] offers cost reductions in the use of ILs in biofuel production.

  • 243.
    Molin, Elin
    et al.
    Dalarna Univ, Energy Technol, SE-79188 Falun, Sweden.;PPAM Solkraft AB, Corp Res, SE-59072 Ljungsbro, Sweden..
    Stridh, Bengt
    Mälardalen University, School of Business, Society and Engineering, Future Energy Center.
    Molin, Andreas
    PPAM Solkraft AB, Corp Res, SE-59072 Ljungsbro, Sweden.;Linkoping Univ, Dept Management & Engn, Div Energy Syst, SE-58183 Linkoping, Sweden..
    Waeckelgard, Ewa
    Dalarna Univ, Energy Technol, SE-79188 Falun, Sweden..
    Experimental Yield Study of Bifacial PV Modules in Nordic Conditions2018In: IEEE Journal of Photovoltaics, ISSN 2156-3381, E-ISSN 2156-3403, Vol. 8, no 6, p. 1457-1463Article in journal (Refereed)
    Abstract [en]

    This study reports on the first full-year field study in Sweden using bifacial photovoltaic modules. The two test sites are located on flat roofs with a low albedo of 0.05 in Linkoping (58 degrees N) and were studied fromDecember 2016 to November 2017. Site 1 has monofacial and bifacial modules with a 40 degrees tilt facing south, which is optimal for annual energy yield for monofacial modules at this location. Site 2 has monofacial 40 degrees tilt south-facing modules and bifacial vertical east-west orientated modules. The annual bifacial energy gain (BGE) was5% at site 1 and1% at site 2 for albedo 0.05. The difference in power temperature coefficients between bifacial and monofacial modules was estimated to influence BG(E) by + 0.4 and + 0.1 percentage points on site 1 and 2, respectively. A higher albedo could be investigated on a sunny day with fresh snow for the bifacial east-west modules. The specific yield was 7.57 kWh/kW(p), which was a yield increase of 48% compared with tar paper at similar solar conditions.

  • 244.
    Momayez, Forough
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. Isfahan University of Technology.
    Karimi, Keikhosro
    Isfahan University of Technology.
    Karimi, Shiva
    Isfahan University of Technology.
    Sárvári Horváth, Ilona
    University of Borås, Faculty of Textiles, Engineering and Business.
    Efficient hydrolysis and ethanol production from rice straw by pretreatment with organic acids and effluent of biogas plant2017In: RSC Advances, E-ISSN 2046-2069, Vol. 7, no 80, p. 50537-50545Article in journal (Refereed)
    Abstract [en]

    The effluent of biogas production plant was used for the pretreatment of rice straw for the improvement of ethanol production. In addition, the organic active ingredients of the effluent, i.e., acetic, butyric, lactic and propionic acids (1-4%), as well as water were employed for the pretreatment at 100 and 140 °C. The results indicated that pretreatment at 100 °C had no significant effect on the performance of subsequent enzymatic hydrolysis and ethanol production by simultaneous saccharification and fermentation (SSF). Among different types of organic acids presented in the effluent, lactic acid showed a better performance. The highest concentration of glucose and ethanol were achieved after 72 h enzymatic hydrolysis and SSF from the straw pretreated at 140 °C with 4% lactic acid. Applying the effluent for the straw pretreatment at 140 °C resulted in an increase in glucose and ethanol concentrations by 42.4 and 47.5%, respectively, compared to those from untreated samples. SEM, FTIR, BET, BJH, and compositional analyses were used to characterize the changes in the structure and composition of rice straw by the pretreatment. Changes in the straw swelling, cellulose crystallinity, pore size distribution, and composition were responsible for the acquired improvements.

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  • 245. Moradian, Farzad
    et al.
    Tchoffor, Placid A.
    Davidsson, Kent O.
    Pettersson, Anita
    Backman, Rainer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Thermodynamic equilibrium prediction of bed agglomeration tendency in dual fluidized-bed gasification of forest residues2016In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 154, p. 82-90Article in journal (Refereed)
    Abstract [en]

    Dual fluidized-bed (DFB) gasification is one of the recently developed technologies for production of heat, power, transportation fuels and synthetic chemicals through steam gasification of biomass. Bed agglomeration is a serious ash-related problem that should be taken into account when biomass-based fuels are selected for fluidized bed gasification and combustion. This study developed a thermodynamic equilibrium model to assess the risk of bed agglomeration in gasification and combustion reactors of a DFB gasifier using biomass (forest residues) as feedstock. The modelling approach combined thermodynamic equilibrium calculations with chemical fractionation technique to predict the composition and melting behaviour of the fuel-derived ash as well as bed particles coating layer in the gasification and combustion reactors. FactSage was employed for the thermodynamic equilibrium calculations. The modelling results were then compared with experimental data obtained from a full-scale DFB gasifier to estimate the reliability and validity of the predictive model. In general, a good agreement was found between the modelling results and experimental observations. For the forest residues as feedstock and olivine as bed material, the modelling results indicate a low risk of bed agglomeration in the DFB gasifier, as long as the dominant temperature in the combustion zone is below 1020 degrees C. In contrast, quartz as bed material in the DFB gasifier was shown to significantly increase the risk of bed agglomeration through coating-induced agglomeration mechanism. 

  • 246.
    Morgalla, Mario
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Seemann, Martin
    Chalmers University of Technology, Sweden.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Characterization of particulate matter formed during wood pellet gasification in an indirect bubbling fluidized bed gasifier using aerosol measurement techniques2015In: Fuel processing technology, ISSN 0378-3820, E-ISSN 1873-7188, Vol. 138, p. 578-587Article in journal (Refereed)
    Abstract [en]

    This study characterizes particulate matter, organic compounds, and inorganic compounds formed in an atmospheric indirect bubbling fluidized bed gasifier at two different steam-to-fuel ratios using wood pellets as fuel. The sampling and conditioning system consisted of a high-temperature dilution probe to quench aerosol dynamics and condense inorganic vapors, a primary thermodenuder to adsorb tar components, and a secondary thermodenuder to investigate the volatility/thermal stability of the remaining aerosol. Both online and offline instruments were used to characterize the aerosol in terms of number size distribution, mass size distribution, particle mass concentration, particle number concentration, morphology, and elemental analysis. Size distributions with three distinct modes were established. The fine and intermediate modes were mainly formed by tar and alkali vapors that had condensed in the sampling and conditioning systems. The coarse mode mainly consisted of the original particles, which are char, fly ash, and fragmented bed material. At the higher steam-to-fuel ratio, tar components seem to be reduced and more coarse-mode particles emitted compared to the low steam case. Furthermore, a possibility for online monitoring of heavy tar is suggested. (C) 2015 Elsevier B.V. All rights reserved.

  • 247.
    Morgalla, Mario
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Benzene conversion in a packed bed loaded with biomass char particles2018In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 32, no 1, p. 554-560Article in journal (Refereed)
    Abstract [en]

    This study investigates the conversion of benzene in a packed bed containing fine char particles. Benzene and steam were simultaneously supplied to a tubular ceramic reactor that was heated electrically. Fragmented char particles were suspended and continuously supplied via a separate supply line. A packed bed of crushed alumina balls was positioned in the reactor to retain the char particles. The benzene conversion in the hot char bed was investigated by varying the bed temperature (900–1100 °C), steam concentration (0–27 vol %), and char concentration (5–50 g Nm–3). The highest conversions achieved in the experiments were approximately 75%. At comparable char concentrations, similar benzene conversions occurred at 900 and 1000 °C. Increasing the temperature to 1100 °C or increasing the steam concentration reduced the benzene conversion. The results indicate that the reduced conversion was due to enhanced char gasification reactions at elevated temperatures and steam concentrations and thus to reduced char mass in the packed bed.

  • 248.
    Morgalla, Mario
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lin, Leteng
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Decomposition of benzene using char aerosol particles dispersed in a high-temperature filter2017In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 118, p. 1345-1352Article in journal (Refereed)
    Abstract [en]

    In this study the tar-removal suitability of char particles finely dispersed in a high-temperature filter was investigated. Benzene was selected as the model tar. An aerosol-based method was designed and used to investigate the benzene decomposition behaviour. Two types of char were used: commercially available activated charcoal and pine char prepared in the laboratory. The conversion behaviour of both chars was investigated in the temperature range between 750 and 900 °C using steam as the gasification medium. During the experiments, different benzene concentrations, amounts of deposited char and gas residence times were tested. The results indicate that both activated carbon and pine char reduced the benzene concentration. Activated carbon generally produced higher and more stable benzene conversions compared to the pine char particles. Decreasing the benzene concentration or increasing the gas residence time or char mass improved the benzene conversion. It was concluded that the char gasification rate became slower while benzene was simultaneously converted. The aerosol-based method was also used to investigate benzene decomposition behaviour while continuously supplying fresh char particles together with steam at 1000 °C. In that way, the deactivated and gasified char particles were steadily replaced, preventing the benzene conversion from decreasing over time.

  • 249.
    Mukesh Kumar, Awasthi
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
    Lukitawesa, Lukitawesa
    University of Borås, Faculty of Textiles, Engineering and Business.
    Duan, Y M
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Zhang, Z Q
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, PR China.
    Bacterial dynamics during the anaerobic digestion of toxic citrus fruit waste and semi-continues volatile fatty acids production in membrane bioreactors2022In: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 319, article id 123812Article in journal (Refereed)
    Abstract [en]

    Citrus wastes (CW) are normally toxic to anaerobic digestion (AD) because of flavors such as D-limonene. In this study, bacterial community was evaluated during volatile fatty acids (VFAs) production from CW inoculated by sludge in a membrane bioreactor (MBR) using semi-continuous AD with different organic loading rates (OLR). Four treatments including untreated CW filled with 4 and 8 g center dot VS center dot L(-1)d(-1) OLR (UOLR4 and UOLR8), pretreated Dlimonene-free CW filled with 4 and 8 g center dot VS center dot L(-1)d(-1) OLR (POLR4 and POLR8). The initial inoculum and the CW mixture (DAY0) was used as control for comparison. There was an obviously higher bacterial diversity in raw material (66848 sequences in DAY0), while decreased after AD and higher in POLR4 and POLR8 (65239 and 63916) than UOLR4 and UOLR8 (49158 and 51936). The key bacterial associated with VFAs production mainly affiliated to Firmicutes (37.35-84.73%), Bacteroidetes (0.48-36.87%), and Actinobacteria (0.35-29.38%), and the key genus composed of Lactobacillus, Prevotella, Bacillus, Bacteroides and Olsenella which contributed in VFA generation by degradable complex organic compounds. Noticeably, methanogen completely suppressed after MBR-AD and UOLR4 has greater acid utilizing bacteria (70.09%).

  • 250.
    Mukesh Kumar, Awasthi
    et al.
    University of Borås, Faculty of Textiles, Engineering and Business. College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Wainaina, Steven
    Mahboubi, Amir
    University of Borås, Faculty of Textiles, Engineering and Business.
    Zhang, Z Q
    College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
    Taherzadeh, Mohammad J
    University of Borås, Faculty of Textiles, Engineering and Business.
    Methanogen and nitrifying genes dynamics in immersed membrane bioreactors during anaerobic co-digestion of different organic loading rates food waste2021In: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 342, article id 125920Article in journal (Refereed)
    Abstract [en]

    This work was aimed to evaluate the distinctive food waste (FW) organic loading rates (OLR) on methanogen and nitrifying genes dynamics and its correlation with identified relative abundance of bacterial dynamics during the anaerobic digestion. This experiment were carried out in the digesters at high OLR of food wastes at (4 to 8 g volatile solids/liter/day reactor R1) and (6 to 10 g volatile solids/liter/day reactor R2). The results shown that the relative abundance of mcrA, mcrB and mcrG genes were richest in the first day of both R1 and R2. In addition, the most of nitrifying genes were greater in after 34 days digestion in R2, while these genes did not show the specific regularity in R1. Finally, the correlation figure shows that Clostridium and Lactobacillus genera were significantly correlated with the different organic acids and methanogen and nitrifying genes dynamics.

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