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  • 1.
    Adolfsson, Beatrice
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Johansson Mess, Marja
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Driftoptimering av lakvatten­­rening: Jämförelse mellan tekniker för uppvärmning av nitrifikationsdammen på Häringetorp avfalls­anläggning2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Biologisk lakvattenrening, med hjälp av mikroorganismer, används på Häringetorp avfallsanläggning för att bland annat reducera mängden kväve i lakvattnet. För att möjliggöra en längre reningsperiod, eftersom mikro­organismernas tillväxt hämmas vid låga temperaturer, vill Tekniska förvaltningen på Växjö kommun studera möjligheten att värma upp nitrifikationsdammen på Häringetorp avfallsanläggning med hjälp av grön energi.

    Kvantifiering av effektbehov för förlängning av reningsperioden har gjorts utifrån en simuleringsmodell. Studie av tillförd effekt har gjorts under det första året med tillförd effekt. Jämförelse mellan de tekniska lösningarna solfångare, värmepump och biobränslepanna har gjorts gällande aspekterna driftsäkerhet, praktisk genomförbarhet, enkelhet och ekonomi. Utifrån diskussion ges rekommendation att installera en värmepump, vilken utnyttjar intern energi, för att levererar en effekt till nitrifikationsdammen på 100 kW under temperaturstyrda förhållanden. Denna tillförsel av effekt förväntas ge en förlängning av reningsperioden på fyra veckor.  

  • 2.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Glass surface modification by aerosol technique2016Other (Refereed)
    Abstract [en]

    Glass has been a key material for many important advnces in cilivilization.  Currently there is much scientific and technological interest to obtained flat/float glass surface that has extremely highly resistant to abrasion, anti-fingerprint, surface contamination and optical dimming. The aim of current project is to develop new routes to modify the glass surface in order to increase functionality and enhance performance in various existing and future areas of application. This will be achieved by modifying the glass surface by incorporating nitrogen to the flat/float glass surface by deposition of thin coatings of AlN, Si3N4 and TiN. This will be achieved by gas to particle conversion by physiochemical routs. Thin films of elemental nitrides have not been reported previously by aerosol technique and we anticipate that these can be used to enhance the mechanical, optical and chemical properties of flat/float glass surface. Techniques used for structural and physical characterization include, SEM, TEM, AFM, Raman, thermal analysis, mechanical and optical measurements. Areas of applications of these modified surfaces include automotive, architectural, laser optics, camera lenses, optical filters and display technologies.

  • 3.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    New Oxynitride Glasses and Thin Films2017In: 15th International Symposium on Advanced Materials (ISAM), Islamabad, Pakistan, 16-20 Oct 2017, 2017Conference paper (Refereed)
  • 4.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Bogdonoff, Toni
    Jönköping University.
    Seifeddine, Salem
    Jönköping University.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Hardness, elastic modulus and refractive index of oxynitride glasses prepared from woody biofuel ashes2017In: Physics and Chemistry of Glasses - European Journal of Glass Science and Technology Part B, ISSN 1753-3562, Vol. 58, no 6, p. 231-236Article in journal (Refereed)
    Abstract [en]

    This paper reports the hardness, elastic modulus and refractive index values of the oxynitride glasses prepared from woody biofuel ashes. The glasses were prepared in nitrogen atmosphere at 1350–1500°C with addition of Ca metal as a precursor to the extra addition of this modifier. The glasses were homogenous, but appeared translucent grey to black. They contained up to 23 eq% of Ca and 5 eq% of N. The glass densities vary slightly between 2.76 to 2.92 g/cm3. The molar volume and compactness values vary between 8.01 cm3/mol to 8.31 cm3/mol and 0.446 to 0.462 respectively. Mechanical properties like hardness and reduced elastic modulus show values, up to 10 and 105 GPa, respectively. These properties are strongly correlated with the amount of N in the glass. The refractive index (1.54–1.75) increases with increasing N and Ca contents.

  • 5.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Difficulties associated with the formation of oxynitride glasses2014Conference paper (Refereed)
  • 6.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Formation and properties of nitrogen rich Ca-Si- (Al)-O-N glasses and Ceramics2014In: Conference proceeding 2014 Spring World Congress on Engineering and Technology, Shanghai, China (April 2014)., 2014, p. 59-59Conference paper (Refereed)
  • 7.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Properties of nitrogen rich mixed La-Pr silicon oxynitride glasses2014Conference paper (Refereed)
  • 8.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Thermal properties of calcium silicon oxynitride glasses2015Conference paper (Refereed)
    Abstract [en]

    Oxynitride glasses are a branch of high performance glasses, obtained by incorporation of nitrogen atoms into oxide glass network. [1-3]Oxynitride glasses have superior mechanical, rheological and optical properties as compared to their oxide glass counter partner [2-5]. Properties of these glasses can be tailored by changes in nitrogen content and additions of various alkaline-earth and or rare-earth elements. Ca- Si-O-N glasses containing high amount of nitrogen and modifiers have been prepared by melting the mixture of CaH2, SiO2 and Si3N4 powder in nitrogen atmosphere. The glasses were characterized by X-ray powder diffraction, differential thermal analysis and scanning electron microscopy. The obtained glasses were found to be homogenous, and having colour opaque black[3]. These glasses show high values of glass transition temperature (1050°C), and crystallization temperatures (1150°C) measured by differential thermal analysis.  Generally the Ca-Si-O-N glasses thermal properties evolve approximately linearly with the nitrogen content. The viscosity increases significantly with the nitrogen content and reaches viscosity values close to reported values for rare-earth silica oxynitride glasses. The apparent viscosity activation energies are very high, ranging from 855 to 2170 kJ/mole. These nitrogen rich glasses can accordingly be classified as being both very refractory and very fragile.

     

  • 9.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    J. Pomeroy, Michael
    University of Limerick, Ireland.
    Stuart, Hampshire
    University of Limerick, Ireland.
    Issues associated with the development of transparent oxynitride glasses2015In: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 41, no 3, p. 3345-3354Article in journal (Refereed)
    Abstract [en]

    Oxynitride glasses and glass ceramics are increasingly recognized as potential materials in specialist applications in modern industrial sectors. Oxynitride glasses have superior mechanical, rheological and optical properties to their oxide glass counterparts. Properties of these glasses can be tailored by changes in nitrogen content and additions of various alkaline-earth and or rare-earth elements. In contrast to oxide glasses, oxynitride glasses are difficult to prepare which adds to production costs. Furthermore, they contain impurities in the form of elemental silicon and silicides, have poor oxidation resistance in air above their glass transition temperatures and have poor transparency in the visible region. This article reviews the above issues in relation to the potential applications of these glasses.

  • 10.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Mauro, Jan
    Penn State University, USA.
    Properties of nitrogen rich Mg-Ca-Si-O-N glasses2017In: 12th  Pacific Rim Conference on Cermics and Glass Technology including Glass & Optical Materials Meeting, Hawii, USA 21-27 May 2017, 2017, p. 180-180, article id GOMD-S1-061-2017Conference paper (Refereed)
    Abstract [en]

    Mg-Ca-Si-O-N glasses containing high amount of nitrogen have been prepared by melting the mixture of Mg metal, Ca metal, SiO2 and Si3N4 powders in nitrogen atmosphere using a radio frequency furnace. Chemical composition, surface morphology, glass transition temperature, hardness, reduced elastic modulus and refractive index of the glasses were investigated using X-ray (EDX) point analysis, scanning electron microscopy, differential thermal analysis, nanoindentation, and spectroscopic ellipsometry. Mg was substituted for Ca in these glasses. The obtained glasses were found to be homogenous, and most of them were not transparent in the visible region. These glasses show high values of glass transition temperature (1020°C), and crystallization temperatures (1150°C). The hardness and reduced elastic modulus increases upon substitution by Mg, up to 13 GPa and 150 GPa respectively. The refractive index of the glasses was found to decrease upon increasing substitution by Mg.

  • 11.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Corning Inc, USA.
    Paul, Biplab
    Linköping University.
    Magnusson, Roger
    Linköping University.
    Broitman, Esteban
    Linköping University.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Linköping University.
    Birch, Jens
    Linköping University.
    Synthesis and characterization of the mechanical and optical properties of Ca-Si-O-N thin films deposited by RF magnetron sputtering2017In: Surface & Coatings Technology, ISSN 0257-8972, E-ISSN 1879-3347, Vol. 315, p. 88-94Article in journal (Refereed)
    Abstract [en]

    Ca-Si-O-N thin films were deposited on commercial soda-lime silicate float glass, silica wafers and sapphire substrates by RF magnetron co-sputtering from Ca and Si targets in an Ar/N-2/O-2 gas mixture. Chemical composition, surface morphology, hardness, reduced elastic modulus and optical properties of the films were investigated using X-ray photoelectron spectroscopy, scanning electron microscopy, nanoindentation, and spectroscopic ellipsometry. It was found that the composition of the films can be controlled by the Ca target power, predominantly, and by the reactive gas flow. Thin films in the Ca-Si-O-N system are composed of N and Ca contents up to 31 eq. % and 60 eq. %, respectively. The films thickness ranges from 600 to 3000 nm and increases with increasing Ca target power. The films surface roughness varied between 2 and 12 nm, and approximately decreases with increasing power of Ca target. The hardness (4-12 GPa) and reduced elastic modulus (65-145 GPa) of the films increase and decrease with the N and Ca contents respectively. The refractive index (1.56-1.82) is primarily dictated by the N content. The properties are compared with findings for bulk glasses in the Ca-Si-(Al)-O-N systems, and it is concluded that Ca-Si-O-N thin films have higher values of hardness, elastic modulus and refractive index than bulk glasses of similar composition. (C) 2017 Elsevier B.V. All rights reserved.

  • 12.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Paul, Biplab
    Linköping University.
    Magnusson, Roger
    Linköping University.
    Greczynski, Grzegorz
    Linköping University.
    Broitman, Esteban
    Linköping University.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Linköping University.
    Birch, Jens
    Linköping University.
    Novel transparent Mg-Si-O-N thin films with high hardness and refractive index2016In: Vacuum, ISSN 0042-207X, E-ISSN 1879-2715, Vol. 131, p. 1-4Article in journal (Refereed)
    Abstract [en]

    There is an increasing demand for glass materials with better mechanical and optical properties for display and electronic applications. This paper describes the deposition of novel thin films of Mg-Si-O-N onto float glass substrates. Amorphous thin films in the Mg-Si-O-N system with high nitrogen and magnesium contents were deposited by reactive RF magnetron co-sputtering from Mg and Si targets in Ar/N2/O2 gas mixtures. The thin films studied span an unprecedented range of compositions up to 45 at% Mg and 80 at% N out of cations and anions respectively. Thin films in the Mg-Si-O-N system were found to be homogeneous and transparent in the visible region. Mechanical properties like hardness (H) and reduced elastic modulus (Er) show high values, up to 21 GPa and 166 GPa respectively. The refractive index (1.87-2.00) increases with increasing magnesium and nitrogen contents.

  • 13.
    Ali, Sharafat
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Paul, Biplab
    Linköping University, Sweden.
    Magnusson, Roger
    Linköping University, Sweden.
    Greczynski, Grzegorz
    Linköping University, Sweden.
    Broitman, Esteban
    Linköping University, Sweden.
    Jonson, Bo
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Eklund, Per
    Linköping University, Sweden.
    Birch, Jens
    Linköping University, Sweden.
    Thin films in M-Si-O-N thin systems2017In: 44th International Conference on Metallurgical Coating and Thin Films (ICMCTF), San Diego, CA, USA, 24-28 Apr 2017, 2017Conference paper (Refereed)
  • 14.
    Bonakdar, Farshid
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Dodoo, Ambrose
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Cost-optimum analysis of building fabric renovation in a Swedish multi-story residential building2014In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 84, p. 662-673Article in journal (Refereed)
    Abstract [en]

    In this study, we analysed the cost-optimum level of building fabric elements renovation in a multi-story residential building. We calculated final energy use for space heating of the building considering a wide range of energy efficiency measures, for exterior walls, basement walls, attic floor and windows. Different extra insulation thicknesses for considered opaque elements and different U-values for new windows were used as energy efficiency measures. We calculated difference between the marginal saving of energy cost for space heating and the investment cost of implemented energy efficiency measures, in order to find the cost-optimum measure for each element. The implications of building lifespans, annual energy price increase and discount rate on the optimum measure were also analysed. The results of the analysis indicate that the contribution of energy efficiency measures to the final energy use reduces, significantly, by increasing the thickness of extra insulation and by reducing the U-value of new windows. We considered three scenarios of business as usual (BAU), intermediate and sustainability, considering different discount rates and energy price increase. The results of this analysis suggest that the sustainability scenario may offer, approximately, 100% increase in the optimum thickness of extra insulation compare to BAU scenario. However, the implication of different lifespans of 40, 50 or 60 years, on the optimum measure appears to be either negligible or very small, depending on the chosen scenario. We also calculated the corresponding U-value of the optimum measures in order to compare them with the current Swedish building code requirements and passive house criteria. The results indicate that all optimum measures meet the Swedish building code. None of the optimum measures, however, meet the passive house criteria in BAU scenario. This study suggests that the employed method of building renovation cost-optimum analyses can be also applied on new building construction to find the cost-optimum design from energy conservation point of view.

  • 15.
    Bonakdar, Farshid
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Sasic Kalagasidis, Angela
    Chalmers University of Technology.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    The Implications of Climate Zones on the Cost-Optimal Level and Cost-Effectiveness of Building Envelope Energy Renovation and Space Heat Demand Reduction2017In: Buildings, ISSN 2075-5309, E-ISSN 2075-5309, Vol. 7, no 2, article id 39Article in journal (Refereed)
    Abstract [en]

    The cost-optimal level of energy performance for buildings shall be identified according to the European directive of 2010. The Swedish building stock needs comprehensive knowledge and an overall strategy for the cost-optimal level of renovation. This paper studies the contribution of Swedish climate zones to the cost-optimal level of renovation on a multi-story residential building in Sweden from the building owner perspective. The building space heat demand is simulated for four Swedish climate zones. The net present profit (NPP) method is defined and used in this study in order to analyze the cost-optimal level and the cost-effective renovation of building envelope components (e.g., attic floor, basement walls, exterior walls and windows). The implication of different discount rates is studied, as well. The results show that the optimum renovation of the building envelope offers 51% more energy savings for space heating when the building is in a northern climate zone compared to a southern zone. The study suggests that different renovation strategies for the building stock renovation need to be identified, separately, for each climate zone. The NPP analysis identifies the minimum required investment and maximum achievable energy savings that are needed to have a cost-effective renovation. The broad range of studied climate zones provides the opportunity to apply the obtained results to other climate zones by either interpolation or extrapolation of NPPs for the buildings with similar characteristics.

  • 16.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Hulteberg, Christain
    Kusar, Henrik
    Kungliga tekniska högskolan.
    A review of thermo-chemical conversion of biomass into biofuels: focusing on gas cleaning and up-grading process steps2017Report (Other (popular science, discussion, etc.))
    Abstract [en]

    It is not easy to replace fossil-based fuels in the transport sector, however, an appealing solution is to use biomass and waste for the production of renewable alternatives. Thermochemical conversion of biomass for production of synthetic transport fuels by the use of gasification is a promising way to meet these goals.

    One of the key challenges in using gasification systems with biomass and waste as feedstock is the upgrading of the raw gas produced in the gasifier. These materials replacing oil and coal contain large amounts of demanding impurities, such as alkali, inorganic compounds, sulphur and chlorine compounds. Therefore, as for all multi-step processes, the heat management and hence the total efficiency depend on the different clean-up units. Unfortunately, the available conventional gas filtering units for removing particulates and impurities, and also subsequent catalytic conversion steps have lower optimum working temperatures than the operating temperature in the gasification units.

    This report focuses on on-going research and development to find new technology solutions and on the key critical technology challenges concerning the purification and upgrading of the raw gas to synthesis gas and the subsequent different fuel synthesis processes, such as hot gas filtration, clever heating solutions and a higher degree of process integration as well as catalysts more resistant towards deactivation. This means that the temperature should be as high as possible for any particular upgrading unit in the refining system. Nevertheless, the temperature and pressure of the cleaned synthesis gas must meet the requirements of the downstream application, i.e. Fischer-Tropsch diesel or methanol.

    Before using the gas produced in the gasifier a number of impurities needs to be removed. These include particles, tars, sulphur and ammonia. Particles are formed in gasification, irrespective of the type of gasifier design used. A first, coarse separation is performed in one or several cyclone filters at high temperature. Thereafter bag-house filters (e.g. ceramic or textile) maybe used to separate the finer particles. A problem is, however, tar condensation in the filters and there is much work performed on trying to achieve filtration at as high a temperature as possible.

    The far most stressed technical barriers regarding cleaning of the gases are tars. To remove the tar from the product gas there is a number of alternatives, but most important is that the gasifier is operated at optimal conditions for minimising initial tar formation. In fluid bed and entrained flow gasification a first step may be catalytic tar cracking after particle removal. In fluid bed gasification a catalyst, active in tar cracking, may be added to the fluidising bed to further remove any tar formed in the bed. In this kind of tar removal, natural minerals such as dolomite and olivine, are normally used, or catalysts normally used in hydrocarbon reforming or cracking. The tar can be reformed to CO and hydrogen by thermal reforming as well, when the temperature is increased to 1300ºC and the tar decomposes. Another method for removing tar from the gas is to scrub it by using hot oil (200-300ºC). The tar dissolves in the hot oil, which can be partly regenerated and the remaining tar-containing part is either burned or sent back to the gasifier for regasification.

    Other important aspects are that the sulphur content of the gas depends on the type of biomass used, the gasification agent used etc., but a level at or above 100 ppm is not unusual. Sulphur levels this high are not acceptable if there are catalytic processes down-stream, or if the emissions of e.g. SO2 are to be kept down. The sulphur may be separated by adsorbing it in ZnO, an irreversible process, or a commercially available reversible adsorbent can be used. There is also the possibility of scrubbing the gas with an amine solution. If a reversible alternative is chosen, elementary sulphur may be produced using the Claus process.

    Furthermore, the levels of ammonia formed in gasification (3,000 ppm is not uncommon) are normally not considered a problem. When combusting the gas, nitrogen or in the worst case NOx (so-called fuel NOx) is formed; there are, however, indications that there could be problems. Especially when the gasification is followed by down-stream catalytic processes, steam reforming in particular, where the catalyst might suffer from deactivation by long-term exposure to ammonia.

    The composition of the product gas depends very much on the gasification technology, the gasifying agent and the biomass feedstock. Of particular significance is the choice of gasifying agent, i.e. air, oxygen, water, since it has a huge impact on the composition and quality of the gas, The gasifying agent also affects the choice of cleaning and upgrading processes to syngas and its suitability for different end-use applications as fuels or green chemicals.

    The ideal upgraded syngas consists of H2 and CO at a correct ratio with very low water and CO2 content allowed. This means that the tars, particulates, alkali salts and inorganic compounds mentioned earlier have to be removed for most of the applications. By using oxygen as the gasifying agent, instead of air, the content of nitrogen may be minimised without expensive nitrogen separation.

    In summary, there are a number of uses with respect to produced synthesis gas. The major applications will be discussed, starting with the production of hydrogen and then followed by the synthesis of synthetic natural gas, methanol, dimethyl ether, Fischer-Tropsch diesel and higher alcohol synthesis, and describing alternatives combining these methods. The SNG and methanol synthesis are equilibrium constrained, while the synthesis of DME (one-step route), FT diesel and alcohols are not. All of the reactions are exothermal (with the exception of steam reforming of methane and tars) and therefore handling the temperature increase in the reactors is essential. In addition, the synthesis of methanol has to be performed at high pressure (50-100 bar) to be industrially viable.

    There will be a compromise between the capital cost of the whole cleaning unit and the system efficiency, since solid waste, e.g. ash, sorbents, bed material and waste water all involve handling costs. Consequently, installing very effective catalysts, results in unnecessary costs because of expensive gas cleaning; however the synthesis units further down-stream, especially for Fischer-Tropsch diesel, and DME/methanol will profit from an effective gas cleaning which extends the catalysts life-time. The catalyst materials in the upgrading processes essentially need to be more stable and resistant to different kinds of deactivation.

    Finally, process intensification is an important development throughout chemical industries, which includes simultaneous integration of both synthesis steps and separation, other examples are advanced heat exchangers with heat integration in order to increase the heat transfer rates. Another example is to combine exothermic and endothermic reactions to support reforming reactions by using the intrinsic energy content. For cost-effective solutions and efficient application, new solutions for cleaning and up-grading of the gases are necessary.

  • 17.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Odenbrand, Ingemar
    Lund university.
    Deactivation and Characterization of SCR Catalysts Used in Municipal Waste Incineration Applications2018In: Catalysis Letters, ISSN 1011-372X, E-ISSN 1572-879X, Vol. 148, no 1, p. 312-327Article in journal (Refereed)
    Abstract [en]

    Catalysts used for selective catalytic reduction were deactivated for various times in a slipstream from a municipal solid waste incineration plant and then characterized. The activity for NO reduction with NH3 was measured. The Brunauer–Emmett–Teller surface areas were determined by N2 adsorption from which the pore size distributions in the mesopore region were obtained. Micropore areas and volumes were also obtained. The composition of fresh and deactivated catalysts as well as fly ash was determined by atomic absorption spectroscopy and scanning electron microscopy with energy dispersive X-ray analysis. The changes in surface area (8% decrease in BET surface area over 2311 h) and pore structure were small, while the change in activity was considerable. The apparent pre-exponential factor was 1.63 × 105 (1/min) in the most deactivated catalyst, compared to 2.65 × 106 (1/min) in the fresh catalyst, i.e. a reduction of 94%. The apparent activation energy for the fresh catalyst was 40 kJ/mol, decreasing to 27 kJ/mol with increasing deactivation. Characterization showed that catalytic poisoning is mainly due to decreased acidity of the catalyst caused due to increasing amounts of Na and K.

  • 18.
    Brandin, Jan
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Odenbrand, Ingemar
    Lund University .
    Poisoning of SCR Catalysts used in Municipal Waste Incineration Applications2017In: Topics in catalysis, ISSN 1022-5528, E-ISSN 1572-9028, Vol. 60, no 17-18, p. 1306-1316Article in journal (Refereed)
    Abstract [en]

    A commercial vanadia, tungsta on titania SCRcatalyst was poisoned in a side stream in a waste incinerationplant. The effect of especially alkali metal poisoningwas observed resulting in a decreased activity at long timesof exposure. The deactivation after 2311 h was 36% whilethe decrease in surface area was only 7.6%. Thus the majorcause for deactivation was a chemical blocking of acidicsites by alkali metals. The activation–deactivation modelshowed excellent agreement with experimental data. Themodel suggests that the original adsorption sites, fromthe preparation of the catalyst, are rapidly deactivated butare replaced by a new population of adsorption sites dueto activation of the catalyst surface by sulphur compounds(SO2, SO3)in the flue gas.

  • 19.
    Brandin, Jan
    et al.
    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.
    Ali, Sharafat
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Aerosolkatalysatorer för industriell gasrening2016Report (Refereed)
    Abstract [en]

    Aerosol catalysts – small particles (with aerodynamic diameter up to 100 m) of catalytically active material suspended in gas – were examined for the intended use of NOx reduction with ammonia (SCR) in smaller industrial plants and boilers as an alternative to SNCR. The aerosol particles are intended to be injected into the flue gas at high temperature, together with ammonia/urea, and then separated on a particulate filter (bag‐type filter) at low temperature. The NOx reduction can occur during the pneumatic transport in the boiler or/and on the catalytically active filter cake. The catalysts must have sufficiently high activity in order to keep down their consumption, they must be cheap enough to be used as a consumable item, and must be harmless to humans and the environment. Two materials were developed during the work as possible candidates: natural zeolites and a FeSO4/activated carbon‐based catalyst. Cost estimates, for a hypothetical 1 MWth plant, shows that a NOx reduction close to 50% economically justify the introduction of SNCR for small plants (<25 GWh, NOx reductions levels between 30‐50% and 2 in stoichiometric ratio), both for the use of urea and liquid anhydrous ammonia with the percent NOx fee of 50 SEK/kg. The result is modest, at best 15‐20% cost reduction compared to no action. Raised tariffs to 60 SEK/kg NOx will improved the situation, but the results are still modest. When the aerosol catalysts was used in the cost estimate, and an assumed NOx reduction degree of 85% was supposed to be reached, good results were obtained at low catalyst costs (0.5‐2 SEK/kg). However the plant can handle at most a cost of 4 SEK/kg. Estimated cost for the aerosol catalyst is in the range of 10 SEK/kg. In order to be economically attractive, the catalyst should be recycled, thereby lowering the cost of catalyst consumption.

  • 20.
    Briggert, Andreas
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Hu, Min
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology. Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Oscarsson, Jan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Evaluation of in-plane and out-of-plane fibre direction in Norway spruce using a laboratory scanner utilising the tracheid effectManuscript (preprint) (Other academic)
  • 21.
    Carlsson, Dennis
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Utvinning av lipider ur matavfall för tillverkning av flytande biobränsle2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I studien undersöktes olika metoder för att bryta ned proteiner och stärkelse i matavfall, så att endast fettet skulle återstå, som råmaterial för biodieselproduktion. Ett modellmatavfall, med känd sammansättning, bröts ned med termisk behandling, sur hydrolys(saltsyra), enzymatisk hydrolys(α-amylas) samt mögelkulturen koji-kin. Efter filtrering av nedbrutet matavfall extraherades fett ur filtratet och ur vissa filterkakor, med hexan. Mängden löst organiskt material i filtraten bestämdes med COD, Chemical Oxygen Demand.

    Det utvunna fettet innehöll fria fettsyror och tros kommit, åtminstone delvis, från matavfallets kött. Som bäst extraherades 40 vikts-% ut av det totala fettet i matavfallet i detta arbete.  Av det fett som extraherats ut kom den största delen (ca 90 %) från filterkakorna, d.v.s. det fasta materialet. Det är oklart om fosfolipasen, som tillsattes vid vätske-vätskeextraktionerna hade någon effekt att bryta eventuellt förekommande emulsioner av lecitin.

    Den sura hydrolysen gav bäst resultat, med den största nedbrytningen av fast material och höga mängder COD, men framför allt gav en filterkaka, som det verkar, rik på fett. Enzymbehandlingarna med amylas behöver dock kompletteras med till exempel proteaser, för att kunna angripa matavfallets proteininnehåll.

    En process togs fram baserat på det bästa resultatet i arbetet, d.v.s. den sura hydrolysen.

  • 22.
    Cedergren, Linnea
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Analys av Torkprocess förgasare Emåmejeriet2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I Sverige finns det stor potential för att utnyttja förgasning av biomassa för el- och värmeproduktion. Forskning och utveckling går framåt både nationellt och internationell men det finns en del kvar för att få förgasningstekniken kommersiell. Vid förgasning av biomassa är fukthalten ett stort problem, det försämrar förgasningsprocessen och minskar på processens värmevärde. Det kan lösas genom att använda sig av en bränsletork.

    I detta arbete presenteras en energi- och massbalans över en torkprocess som är installerad på en förgasningsanläggning i mikroskala på Emåmejeriet i Hultsfred. Analysen kommer att bidra till en större förståelse för hur torkningen fungerar och hur det påverkar fukthalten på utgående bränsle. En bra torkprocess bidrar till en förbättrad förgasningsprocess i framtiden.

    Resultatet visar att torken torkar bränslet och ger en låg fukthalt som gör att förgasaren fungerar bra. Luften till utloppet av torken har en temperatur på 20 grader och har en relativ fuktighet på 76 % vilket innebär att luften inte blir mättad i torken. Det visar att det finns mer utrymme för att göra en förbättring.

    Enligt mätningar som har gjorts på fukthalten visar att torken lyckas att torka bränsle med en fukthalt på 30-40% till en fukthalt på 5-10%. Den till torkprocessens tillförada värme är spillvärme från förgasaren med en effekt på 23.6 kW och torkeeffekte, alltså den effekt som krävs för att förånga vattnet i bränslet ger 14.5 kW. 

  • 23.
    Cristina dos Santos, Graziely
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Univ. Estadual Paulista, Brazil.
    Forss, Jörgen
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Welander, Ulrika
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Corso, Carlos Renato
    Univ. Estadual Paulista, Brazil.
    Redox mediator evaluation in the azo dye biodegradation2015Conference paper (Refereed)
    Abstract [en]

    Azo dye degradation occurs by means of the oxidation–reduction reactions which have the azo dye acting as final electron acceptor. Some carbon sources can act as electron donors because the products of their metabolism act as redox mediators. In order to enhance the dye biodegradation process, the present study aims to evaluate the decolorization of an artificial wastewater, containing the azo dye Direct Red 75 (DR75), led by a microbial consortium from rice husks, testing the effect in the process of glucose and yeast extract as carbon sources. Samples with and without 0.1 M Sodium phosphate buffer were also analysed. The decolorization was measured by means UV-VIS spectrophotometry. The percentage of decolorization of the samples over the time indicates that the sample with yeast extract, rinse water of rice husks and without buffer presented the best decolorization rate, about 80%. Therefore, the results presented in this study may also suggest that yeast extract is a better carbon source for dye biodegradation than glucose.

  • 24.
    Dale, Virginia H.
    et al.
    Oak Ridge Natl Lab, USA.
    Kline, Keith L.
    Oak Ridge Natl Lab, USA.
    Parish, Esther S.
    Oak Ridge Natl Lab, USA.
    Cowie, Annette L.
    Univ New England, Australia.
    Emory, Robert
    Weyerhaeuser Co, USA.
    Malmsheimer, Robert W.
    SUNY Coll Environm Sci & Forestry, USA.
    Slade, Raphael
    Imperial Coll London, UK.
    Smith, Charles Tattersall (Tat), Jr.
    Univ Toronto, Canada.
    Wigley, Thomas Bently (Ben)
    NCASI, USA.
    Bentsen, Niclas S.
    Univ Copenhagen, Denmark.
    Berndes, Goran
    Chalmers University of Technology.
    Bernier, Pierre
    Canadian Forest Serv, Canada.
    Brandao, Miguel
    Inst Soil Sci & Plant Cultivat, Poland.
    Chum, Helena L.
    NREL, USA.
    Diaz-Chavez, Rocio
    Imperial Coll London, UK.
    Egnell, Gustaf
    Swedish University of Agricultural Science.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Schweinle, Jorg
    Thunen Inst Int Forestry & Forest Econ, Germany.
    Stupak, Inge
    Univ Copenhagen, Denmark.
    Trianosky, Paul
    Sustainable Forestry Initiat Inc, USA.
    Walter, Arnaldo
    State Univ Campinas UNICAMP, Brazil.
    Whittaker, Carly
    Rothamsted Res, UK.
    Brown, Mark
    Univ Sunshine Coast, Australia.
    Chescheir, George
    NCSU, USA.
    Dimitriou, Ioannis
    Swedish University of Agricultural Science.
    Donnison, Caspar
    Univ Southampton, UK.
    Eng, Alison Goss
    US Dept Energy DOE, USA.
    Hoyt, Kevin P.
    Univ Tennessee, USA.
    Jenkins, Jennifer C.
    Enviva LP, USA.
    Johnson, Kristen
    US Dept Energy DOE, USA.
    Levesque, Charles A.
    Innovat Nat Resource Solut LLC, USA.
    Lockhart, Victoria
    Resource Management Serv LLC, USA.
    Negri, Maria Cristina
    Argonne Natl Lab, USA.
    Nettles, Jami E.
    Weyerhaeuser Co, USA.
    Wellisch, Maria
    Agr & Agri Food Canada, Canada.
    Status and prospects for renewable energy using wood pellets from the southeastern United States2017In: Global Change Biology Bioenergy, ISSN 1757-1693, E-ISSN 1757-1707, Vol. 9, no 8, p. 1296-1305Article in journal (Other academic)
    Abstract [en]

    The ongoing debate about costs and benefits of wood-pellet based bioenergy production in the southeastern United States (SE USA) requires an understanding of the science and context influencing market decisions associated with its sustainability. Production of pellets has garnered much attention as US exports have grown from negligible amounts in the early 2000s to 4.6 million metric tonnes in 2015. Currently, 98% of these pellet exports are shipped to Europe to displace coal in power plants. We ask, 'How is the production of wood pellets in the SE USA affecting forest systems and the ecosystem services they provide?' To address this question, we review current forest conditions and the status of the wood products industry, how pellet production affects ecosystem services and biodiversity, and what methods are in place to monitor changes and protect vulnerable systems. Scientific studies provide evidence that wood pellets in the SE USA are a fraction of total forestry operations and can be produced while maintaining or improving forest ecosystem services. Ecosystem services are protected by the requirement to utilize loggers trained to apply scientifically based best management practices in planning and implementing harvest for the export market. Bioenergy markets supplement incomes to private rural landholders and provide an incentive for forest management practices that simultaneously benefit water quality and wildlife and reduce risk of fire and insect outbreaks. Bioenergy also increases the value of forest land to landowners, thereby decreasing likelihood of conversion to nonforest uses. Monitoring and evaluation are essential to verify that regulations and good practices are achieving goals and to enable timely responses if problems arise. Conducting rigorous research to understand how conditions change in response to management choices requires baseline data, monitoring, and appropriate reference scenarios. Long-term monitoring data on forest conditions should be publicly accessible and utilized to inform adaptive management.

  • 25.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Climate change impacts on overheating risk and primary energy use for space conditioning of a Swedish multi-story building2016In: CLIMA 2016: Proceedings of the 12th REHVA World Congress / [ed] Per Kvols Heiselberg, 2016Conference paper (Refereed)
    Abstract [en]

    In this study we investigate the potential impacts of future climate change scenarios on overheating risk and primary energy use for space conditioning of a newly built multi-story apartment building in Växjö, Sweden. The building is district heated and potentially cooled by stand-alone air conditioners. We consider climate change scenarios for the period 2050-2059, historical climate of 1961-1990 and recent climate of 1996-2005. The climate change scenarios are based on the representative concentration pathways 4.5 and 8.5. We explore the risk of overheating of the building and analyse the impacts of different strategies for overheating control, including increased airing and solar shading besides mechanical cooling. We investigate the implications of different renewable based electricity supply options for space cooling and ventilation of the building. The results show that the space heating demand is significantly reduced and cooling demand is strongly increased for the building with the future climate scenarios. Furthermore the risk of overheating increases under the climate change scenarios. Among the overheating control strategies analysed, solar shading is the single most effective measure, giving the lowest primary energy use for space conditioning. Complementing the electricity from biomass-fired condensing power plants with solar-based electricity reduced the space conditioning primary energy use by 4-9%. Adding increased airing to the control strategies increased the primary energy use.

  • 26.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Comparative life cycle and carbon footprint analyses of wood building systems designed as conventional or passive house standard2014In: World Sustainable Building 2014 Barcelona Conference: Sustainable Buildings:Results Are We Moving as quickly as we should? It's up to us! Conference Proceedings Volume 2, GBCe , 2014, p. 284-290Conference paper (Refereed)
  • 27.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Economic analyses of energy efficiency renovation measures and packages for a district heated multi-family residential building2016In: 11th Conference on Sustainable Development of Energy, Water and Environment Systems: Book of Abstracts : September 4-9, 2016, Lisbon, Portugal / [ed] Marko Ban, Neven Duić, Mario Costa, Daniel Rolph Schneider, Zvonimir Guzović, Stanislav Boldyryev, Valerie Eveloy, Şiir Kilkiş, Jiří Jaromír Klemeš, Tomislav Pukšec, Leonid Ulyev, Petar Varbanov, Milan Vujanović, Faculty of Mechanical Engineering and Naval Architecture, Zagreb , 2016, p. 321-321, article id 0521Conference paper (Refereed)
    Abstract [en]

    Improved energy efficiency in buildings is a major part of the overall strategy to reduce fossil fuels use and thereby mitigate climate change. In this study, we present and demonstrate an approach for economic analysis of building energy efficiency measures, and investigate the profitability of energy efficiency renovation measures for a Swedish multi-family building. The energy renovation measures include additional insulation to basement, exterior walls, and roof and improved windows. They are analysed when applied either singly or in packages. We find that the cost-effectiveness of the building envelope retrofit measures is very sensitive to the economic-related parameters applied including, real discount rates and energy price increase over time. Cost optimal final energy savings for the energy renovation package varies between 29% and 38%, depending on the choice of real discount rate and energy price increase. This study shows the significance of different building envelope measures and economic-related parameters in achieving large energy savings from building envelope renovation cost-efficiently.

  • 28.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Effect of energy efficiency requirements for residential buildings in Sweden on lifecycle primary energy use2014In: Energy Procedia: INTERNATIONAL CONFERENCE ON APPLIED ENERGY, ICAE2014 / [ed] Yan, J; Lee, DJ; Chou, SK; Desideri, U; Li, H, Elsevier, 2014, p. 1183-1186Conference paper (Refereed)
    Abstract [en]

    In this study we analyze the lifecycle primary energy use of a wood-frame apartment building designed to meet the current Swedish building code or passive house criteria, and heated with district heat or bedrock heat pump. We employ a lifecycle perspective methodology and determine the production, operation and end-of-life primary energy use of the buildings. We find that the passive house requirement strongly reduces the final energy use for heating compared to the current Swedish building code. However, the primary energy use is largely determined by the energy supply system, which is generally outside the mandate of the building standards. Overall, buildings with district heating have lower life-cycle primary energy use than alternatives heated with heat pump. The primary energy for production is small relative to that for operation, but it is more significant as the energy-efficiency standard of building improves and when efficient energy supply is used. Our results show the importance of a system-wide lifecycle perspective in reducing primary energy use in the built environment. A life cycle primary energy perspective is needed to minimize overall primary energy use, and future building energy-efficiency standards may reflect the full energy use during a building's life cycle. This could include primary energy implications for production, operation and end-of-life of buildings.

  • 29.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Energy use and overheating risk of Swedish multi-storey residential buildings under different climate scenarios2016In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 97, p. 534-548Article in journal (Refereed)
    Abstract [en]

    In this study, the extent to which different climate scenarios influence overheating risk, energy use and peak loads for space conditioning of district heated multi-storey buildings in Sweden are explored. Furthermore, the effectiveness of different overheating control measures and the implications of different electricity supply options for space cooling and ventilation are investigated. The analysis is based on buildings with different architectural and energy efficiency configurations including a prefab concrete-frame, a massive timber-frame and a light timber-frame building. Thermal performance of the buildings under low and high Representative Concentration Pathway climate scenarios for 2050–2059 and 2090–2099 are analysed and compared to that under historical climate of 1961–1990 and recent climate of 1996–2005. The study is based on a bottom-up methodology and includes detailed hour-by-hour energy balance and systems analyses. The results show significant changes in the buildings’ thermal performance under the future climate scenarios, relative to the historical and recent climates. Heating demand decreased significantly while cooling demand and overheating risk increased considerably with the future climate scenarios, for all buildings. In contrast to the cooling demand, the relative changes in heating demand of the buildings under the future climate scenarios are somewhat similar. The changes in the space conditioning demands and overheating risk vary for the buildings. Overheating risk was found to be slightly higher for the massive-frame building and slightly lower for the light-frame building.

  • 30.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Bonakdar, Farshid
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Effects of future climate change scenarios on overheating risk and primary energy use for Swedish residential buildings2014In: Energy Procedia: INTERNATIONAL CONFERENCE ON APPLIED ENERGY, ICAE2014 / [ed] Yan, J; Lee, DJ; Chou, SK; Desideri, U; Li, H, Elsevier, 2014, p. 1179-1182Conference paper (Refereed)
    Abstract [en]

    In this study we use dynamic computer simulation modelling to investigate the potential impact of future climate change scenarios on the risk of overheating and annual primary energy requirements for space heating and cooling of residential buildings in Växjö, Sweden. The buildings are designed to the energy efficiency level of conventional or passive house, and are assumed to be heated with district heating and cooled with mechanical cooling system. We compare different climate change scenarios to a baseline which represents the climate data of Växjö for 1996-2005. The climate change scenarios are based on projected temperature changes under the representative concentration pathways (RCP) 4.5 and 8.5 scenarios. The result shows that the risk of overheating increases under the climate change scenarios. Furthermore space heating demand is reduced and cooling demand is increased for the analyzed buildings, and the changes are proportionally more significant for the passive compared to the conventional building.

  • 31.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Climate impacts of wood vs. non-wood buildings2016Report (Other academic)
    Abstract [en]

    This report documents the findings of a project commissioned by the SwedishAssociation of Local Authorities and Regions on energy and climateimplications of building structural-frame materials from a life cycle perspective.The report is compiled by researchers within the Sustainable Built EnvironmentGroup (SBER) at Linnaeus University, Växjö, Sweden, and it addresses theterms of reference of the project agreement, including review of existingliterature and reports on energy and climate implications of wood-frame andnon-wood-frame building systems.The report’s primarily focus is: the effect of material choice on different lifecycle stages of a building; the significance of building frame material in relationto the total primary energy use and climate impact of a building; keymethodological issues linked to life cycle analysis of buildings; and theimportance of system perspective in analysis of a building’s climate impacts.

  • 32.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lifecycle carbon implications of conventional and low-energy multi-storey timber building systems2014In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 82, p. 194-210Article in journal (Refereed)
    Abstract [en]

    A consequential-based lifecycle approach is used here to explore the carbon implications of conventional and low-energy versions of three timber multi-storey building systems. The building systems are made of massive wood using cross laminated timber (CLT) elements; beam-and-column using glulam and laminated veneer lumber (LVL) elements; and prefabricated modules using light-frame volume elements. The analysis encompasses the entire resource chains during the lifecycle of the buildings, and tracks the flows of carbon from fossil energy, industrial process reactions, changes in carbon stocks in materials, and potential avoided fossil emissions from substitution of fossil energy by woody residues. The results show that the low-energy version of the CLT building gives the lowest lifecycle carbon emission while the conventional version of the beam-and-column building gives the highest lifecycle emission. Compared to the conventional designs, the low-energy designs reduce the total carbon emissions (excluding from tap water heating and household and facility electricity) by 9%, 8% and 9% for the CLT, beam-and-column and modular systems, respectively, for a 50-year lifespan located in Växjö. The relative significance of the construction materials to the fossil carbon emission varies for the different energy-efficiency levels of the buildings, with insulation dominating for the low-energy houses and plasterboard dominating for the conventional houses.

  • 33.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lifecycle primary energy analysis of low-energy timber building systems for multi-story residential buildings2014In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 81, p. 84-97Article in journal (Refereed)
    Abstract [en]

    A system-wide lifecycle approach is used here to explore the primary energy implications of three timber building systems for a multi-storey building designed to a high energy-efficiency level. The three building systems are: cross laminated timber, beam -and-column, and modular prefabricated systems. The analysis considers the energy and material flows in the production, use and post-use lifecycle stages of the buildings. The effects of insulation material options and the contribution of different building elements to the production energy for the buildings are explored. The results show that external and internal walls account for the biggest share of the production energy for all building systems and its contribution is comparable for the different systems. In contrast, there is significant variation in the production primary energy for the roof-ceilings and intermediate floor-ceilings for the different building systems. Overall, the cross laminated timber building system gives the lowest lifecycle primary energy balance, as this building is insulated with stone wool and has better airtightness in contrast to the other building systems which are insulated with glass wool and have lower airtightness performance. With improved airtightness and insulation substitution, the total primary energy use for the beam-and-column and modular building systems can be reduced by 7% and 9%, respectively.

  • 34.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Modeling Carbon Footprint of Wood-Based Products and Buildings2015In: The Carbon Footprint Handbook / [ed] Subramanian Senthilkannan Muthu, London: CRC Press, 2015, p. 143-162Chapter in book (Refereed)
  • 35.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Recycling of lumber2014In: Handbook of recycling: state-of-the-art for practitioners, analysts, and scientists / [ed] Ernst Worrell and Markus A. Reuter, Waltham, MA: Elsevier, 2014, 1, p. 151-163Chapter in book (Refereed)
    Abstract [en]

    Wood from sustainably managed forests can play important roles both as material and as fuel in a transition to a low-carbon society. Wood is widely used as an energy source and as a physical and structural material in diverse applications, including furniture and joinery, pulp and paper, and construction material. There is large potential to improve resource efficiency and thereby reduce greenhouse gas (GHG) emissions through efficient management of post-use wood materials. This chapter explores post-use management of wood products from resource efficiency and climate perspectives. Primary energy and GHG balances are important metrics to understand the resource efficiency of climate change mitigation strategies involving post-use wood products. Primary energy use largely determines natural resource efficiency and steers the environmental impacts of material recovery and production. This chapter describes the mechanisms through which post-use management of recovered wood materials can affect primary energy use and GHG impacts of wood products. To further understand the implications of different post-use management options for wood products, we then explore several quantitative case-studies.

  • 36.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Final energy savings and cost-effectiveness of deep energy renovation of a multi-storey residential building2017In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 135, p. 563-576Article in journal (Refereed)
    Abstract [en]

    In this study we present a method for analysis of cost-effectiveness of end-use energy efficiency measures and demonstrate its application for modelling a wide range of energy renovation measures for a typical 1970s multi-family building in Sweden. The method integrates energy balance and bottom-up economic calculations considering total and marginal investment costs of energy efficiency measures as well as net present value of total and marginal savings of the measures. The energy renovation measures explored include additional insulation to basement walls, exterior walls, and attic floor, improved new windows, efficient electric appliances and lighting, efficient water taps, glazed enclosed balcony systems, and exhaust air ventilation heat recovery systems. The measures are analysed first individually and then designed to form economic packages. Our results show that improved windows give the biggest single final energy savings while resource-efficient taps is the most cost-effective measure for the building. We find that the cost-effectiveness of the energy renovation measures is sensitive to real discount rates and energy price increases. Cost-optimal final heat savings varies between 34% and 51%, depending on the choice of real discount rate and energy price increase. The corresponding electricity savings varies between 35% and 43%. This study shows a method and the significance of various technical and economic-related parameters in achieving deep energy savings cost-efficiently.

  • 37.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Life cycle primary energy use of nearly-zero energy building and low-energy building2017In: ECEEE 2017 Summer Study: Consumption, Efficiency & Limits, European Council for an Energy Efficient Economy (ECEEE), 2017, p. 1075-1081Conference paper (Refereed)
    Abstract [en]

    Energy legislations are increasingly driving towards buildings with very low operation final energy use as part of efforts to reduce energy use and climate impact of the built environment. In this study we analyse the life cycle primary energy use of a recently constructed Swedish conventional 6-storey apartment building and compare it to variants designed as nearly-zero energy building or as low-energy building with a combination of improved thermal envelope and passive design strategies. We maintain the architectural design of the constructed building and improve the thermal properties of the envelope to achieve a low-energy building and also nearly-zero energy building including solar thermal collectors. We consider scenarios where the building variants are heated with renewable energy using cogenerated district heating, also complemented with solar heating system. We follow the life cycle of the building versions and analyse their total primary energy use, considering the production, operation and end-of-life phases. The results show that the relative significance of the production phase increases as buildings are made to achieve very low operational energy use. The production phase accounts for 17 % of the total primary energy use for production, operation and demolition of the constructed building for a 50-year lifespan. The corresponding values for the nearly-zero energy and low-energy building variants ranges between 30 to 31 %. Overall, the life cycle primary energy use for the nearly-zero energy and low-energy building variants are about 30–35 % lower compared to the constructed building.

  • 38.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Truong, Nguyen Le
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Primary energy benefits of cost-effective energy renovation of a district heated multi-family building under different energy supply systems2018In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 143, p. 69-90Article in journal (Refereed)
    Abstract [en]

    The European Union's Directive on energy performance of buildings emphasizes the need to take cost-effectiveness into account when measures are implemented for improved building energy efficiency. In this study, we investigate cost-effective energy renovation measures for a district heated building under different contexts, including varied locations, energy supply systems and economic scenarios. We determine the final and primary energy savings of cost-effective energy renovation packages for the building in the different contexts. The measures analysed include: improved insulation for attic floor, basement walls, and exterior walls; improved windows and doors; resource-efficient taps; heat recovery of exhaust ventilation air; energy-efficient household appliances and lighting. We consider three existing Swedish energy supply systems of varying district heat production scale and tariffs, and also plausible renewable-based energy supply systems. Our analysis calculates the final energy savings of the measures including the cost-effective renovation packages on hourly basis and links these to the different energy supply systems. The cost-effectiveness analysis is based on a double-stage optimization method, considering total and marginal investment costs of renovation measures as well as associated net present values of total and marginal cost savings. The results show that significant final and primary energy savings can be achieved when energy renovation measures are implemented for the building in the different contexts. This study shows that heat demand in existing Swedish building could be about halved while electricity use may be reduced considerably with cost-effective energy renovation measures. The economic viability of the renovation measures is sensitive to the economic regimes especially discount rates and energy price increase.

  • 39.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Energy Simulation of Existing Swedish Multi-Storey Apartment Building in Växjö: Work Package 2, Task 2.1, carried out by UNI-SE in the Ready Project2016Report (Other academic)
  • 40.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Influence of simulation assumptions and input parameters on energy balance calculations of residential buildings2017In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 120, no 1, p. 718-730Article in journal (Refereed)
    Abstract [en]

    In this study, we modelled the influence of different simulation assumptions on energy balances of two variants of a residential building, comprising the building in its existing state and with energy-efficient improvements. We explored how selected parameter combinations and variations affect the energy balances of the building configurations. The selected parameters encompass outdoor microclimate, building thermal envelope and household electrical equipment including technical installations. Our modelling takes into account hourly as well as seasonal profiles of different internal heat gains. The results suggest that the impact of parameter interactions on calculated space heating of buildings is somewhat small and relatively more noticeable for an energy-efficient building in contrast to a conventional building. We find that the influence of parameters combinations is more apparent as more individual parameters are varied. The simulations show that a building's calculated space heating demand is significantly influenced by how heat gains from electrical equipment are modelled. For the analyzed building versions, calculated final energy for space heating differs by 9-14 kWh/m(2) depending on the assumed energy efficiency level for electrical equipment. The influence of electrical equipment on calculated final space heating is proportionally more significant for an energy-efficient building compared to a conventional building. This study shows the influence of different simulation assumptions and parameter combinations when varied simultaneously. (C) 2016 Elsevier Ltd. All rights reserved.

  • 41.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    On input parameters, methods and assumptions for energy balance and retrofit analyses for residential buildings2017In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 137, p. 76-89Article in journal (Refereed)
    Abstract [en]

    In this study we explore key parameter values, methods and assumptions used for energy balance modelling of residential buildings in the Swedish context and analyse their effects on calculated energy balance of a typical multi-storey building from 1970s and on energy savings of energy efficiency retrofit measures. The parameters studied are related to microclimate, building envelope, occupancy behaviour, ventilation, and heat gains from electric appliances and persons. Our study shows that assumed indoor air temperature, internal heat gains and efficiency of ventilation heat recovery units have significant effect on the simulated energy performance of the studied building and energy efficiency measures. Of the considered microclimate parameter values and assumptions, the outdoor temperature, ground solar reflection and window shading have significant impact on the simulated space heating and cooling demands. On the contrary, the simulated energy performances are less affected by the variations in air pressure outside and the percentage of wind load that hits the building. We found that input data and assumptions used for energy balance calculations and energy saving analyses vary significantly in the Swedish context. These result in significantly different calculated final energy performance of buildings and energy efficiency measures. To inform accurate analysis of energy performance of building and energy saving measures, input parameters used in simulation models need to be appropriate.

  • 42.
    Druenert, F.
    et al.
    Univ Jena, Germany.
    Blanz, M.
    Univ Jena, Germany;Univ Highlands & Isl, UK.
    Pollok, K.
    Univ Jena, Germany.
    Pan, Z.
    Univ Jena, Germany.
    Wondraczek, L.
    Univ Jena, Germany.
    Möncke, Doris
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Natl Hellen Res Fdn, Greece.
    Copper-based opaque red glasses - Understanding the colouring mechanism of copper nanoparticles in archaeological glass samples2018In: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 76, p. 375-381Article in journal (Refereed)
    Abstract [en]

    Red opaque glasses of two different sites in central Germany, a medieval glassworks in Glashutten, Taunus Mountains, and an early modern glassworks in Wieda, Harz Mountains, were analysed with regard to their optical appearance. By scanning electron microscopy and X-ray diffraction, metallic copper nanoparticles were identified as a conspicuous constituent in these glasses. In addition, similar opaque red glasses were reproduced in the laboratory in order to better understand the manufacturing process. Detailed analysis of the optical scattering was conducted in order to evaluate the role of Cu-0 nanoparticles in the colouring mechanism relative to other possible reasons of colouration. We find clear differences between the possible contributions of Cu2O (cuprite) particles and metallic copper (Cu-0) nanoparticles. Through simulated backscattering spectra we were able to calculate an average copper particle radius in the archaeological glass samples resulting in a value of up to 95 nm, which matches well the results of SEM investigation (minimum 65 nm). Using the methods we applied in this study, it becomes possible to reconstruct various processing conditions as they were applied in medieval manufacture of these particular materials. (C) 2018 Elsevier B.V. All rights reserved.

  • 43.
    Finnerman, Oskar
    et al.
    Chalmers University of Technology.
    Razmjoo, Narges
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Guo, Ning
    Chalmers University of Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Ström, Henrik
    Chalmers University of Technology.
    Reactor modelling assessment for urea-SNCR applications2017In: International journal of numerical methods for heat & fluid flow, ISSN 0961-5539, E-ISSN 1758-6585, Vol. 27, no 7, p. 1395-1411Article in journal (Refereed)
    Abstract [en]

    Purpose

    This work aims to investigate the effects of neglecting, modelling or partly resolving turbulent fluctuations of velocity, temperature and concentrations on the predicted turbulence-chemistry interaction in urea-selective non-catalytic reduction (SNCR) systems.

    Design/methodology/approach

    Numerical predictions of the NO conversion efficiency in an industrial urea-SNCR system are compared to experimental data. Reactor models of varying complexity are assessed, ranging from one-dimensional ideal reactor models to state-of-the-art computational fluid dynamics simulations based on the detached-eddy simulation (DES) approach. The models use the same reaction mechanism but differ in the degree to which they resolve the turbulent fluctuations of the gas phase. A methodology for handling of unknown experimental data with regard to providing adequate boundary conditions is also proposed.

    Findings

    One-dimensional reactor models may be useful for a first quick assessment of urea-SNCR system performance. It is critical to account for heat losses, if present, due to the significant sensitivity of the overall process to temperature. The most comprehensive DES setup evaluated is associated with approximately two orders of magnitude higher computational cost than the conventional Reynolds-averaged Navier–Stokes-based simulations. For studies that require a large number of simulations (e.g. optimizations or handling of incomplete experimental data), the less costly approaches may be favored with a tolerable loss of accuracy.

    Originality/value

    Novel numerical and experimental results are presented to elucidate the role of turbulent fluctuations on the performance of a complex, turbulent, reacting multiphase flow.

  • 44.
    Forss, Jörgen
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Continuous system based on rice husks for biodegradation of a simulated textile waste water containing azo dyes2013In: Continuous system based on rice husks for biodegradation of a simulated textile waste water containing azo dyes, International Water Association, Elsevier, 2013Conference paper (Other academic)
  • 45.
    Forss, Jörgen
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lindh, Markus V.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Welander, Ulrika
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Microbial biotreatment of actual textile wastewater in a continuous sequential rice husk biofilter and the microbial community involved2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 1, article id e0170562Article in journal (Refereed)
    Abstract [en]

    Textile dying processes often pollute wastewater with recalcitrant azo and anthraquinone dyes. Yet, there is little development of effective and affordable degradation systems for textile wastewater applicable in countries where water technologies remain poor. We determined biodegradation of actual textile wastewater in biofilters containing rice husks by spectrophotometry and liquid chromatography mass spectrometry. The indigenous microflora from the rice husks consistently performed >90% decolorization at a hydraulic retention time of 67 h. Analysis of microbial community composition of bacterial 16S rRNA genes and fungal internal transcribed spacer (ITS) gene fragments in the biofilters revealed a bacterial consortium known to carry azoreductase genes, such as Dysgonomonas, and Pseudomonas and the presence of fungal phylotypes such as Gibberella and Fusarium. Our findings emphasize that rice husk biofilters support a microbial community of both bacteria and fungi with key features for biodegradation of actual textile wastewater. These results suggest that microbial processes can substantially contribute to efficient and reliable degradation of actual textile wastewater. Thus, development of biodegradation systems holds promise for application of affordable wastewater treatment in polluted environments.

  • 46.
    Fredriksson, Anna
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Mätvärdesbaserad metod för minskade emissioner i mindre förbränningsanläggningar2015Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [sv]

    En mätvärdesbaserad metod har använts för att i den enskilda förbränningsanläggningen kunna visa vilka driftsätt som ger onormalt höga utsläpp. Tre olika typer av anläggningsdata har använts. Metoden fokuserar på gasfasreaktioner för att hållas oberoende av eldningsteknik. För att hålla nere beräkningstider och datorkapacitet fokuserar arbetet på summareaktioner och enkla samband vad gäller kemiska processer och förhållanden i eldstaden. 

  • 47.
    Gavrilovic, Ljubisa
    et al.
    Norwegian University of Science and technology (NTNU), Trondheim, Norway.
    Blekkan, Ed Anders
    Norwegian University of Science and technology (NTNU), Trondheim, Norway.
    Venvik, H.J.
    Norwegian University of Science and technology (NTNU), Trondheim, Norway.
    Holmen, Anders
    Norwegian University of Science and technology (NTNU), Trondheim, Norway.
    Brandin, Jan
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Influence of potassium species on Co based Fischer-Tropsch-catalyst.2016Conference paper (Refereed)
    Abstract [en]

    1. Introduction

    The purpose of this work is better understanding of the alkali influence on Co-based F-T catalyst. Since potassium is one of the elements that can be present in syngas from biomass[1], one of the questions is how potassium species affect the Co catalyst. From previous work it has been shown that alkali species act as poisons, thus deactivating catalysts[2]. Most previous work in this group[3][4] and by others[5] has concerned Co catalysts that were exposed to potassium species by incipient wetness impregnation, which is essentially different from the real behaviour during the gasification process where the species will mainly be in the vapor phase. In the present work we study potassium influence on a Co-based catalyst, using aerosol technology as a new method for potassium deposition on the Co surface.

     

    2. Experimental

    4 different potassium salts were deposited using aerosol deposition on 20%Co/0.5%Re/γAl2O3. The amount of potassium salts deposited were determined using ICP analysis. Potassium salts were chosen from studies of the gases from biomass gasification[6]. These are K2SO4, KCl, KNO3 and K2CO3. KNO3 will be reduced to KOH during biomass gasification, but since in these experiments temperature was not so high and there was no H2/CO, most likely KNO3 will be deposited as such on the Co surface.

    BET N2 adsorption, H2 chemisorption, temperature programmed reduction (TPR) were used to characterize all the poisoned catalysts.

    Fischer Tropsch activity and selectivity measurements were performed at the in house build set-up, at 210°C, 20 bar and at H2:CO ratio of 2.1. The GHSV was consistently varied to maintain comparable CO conversion levels between 20-50%. A detailed description of the setup and procedures can be found elsewhere[3].

     

    3. Results

    The potassium species were deposited using aerosol technology in the apparatus shown in Fig. 1. Potassium salts are dissolved in deionized water and the solution is placed inside the atomizer, which produces aerosol particles. Nitrogen is used as a carrier gas which forces aerosol particles in the reactor direction. Before entering the reactor, the gas mixture carrying the aerosol is passing the impaction vessel to remove large particles. The catalyst bed is placed in the middle of the reactor, which can be heated up to 800°C. The generated aerosol particles were physically characterized according to their electrical mobility using a scanning mobility particle sizer (SMPS) consisting of a differential mobility analyser (DMA) and a condensation particle counter (CPC)[7]. The three target concentrations of potassium salts,  200 ppm, 800 ppm and 4000 ppm,  were monitored by the above-mentioned instruments.

    Results from characterization by elemental analysis, H2 chemisorption, BET surface area, TPR together with the results from the Fischer Tropsch synthesis i.e. CO conversion, selectivity, and activity will be compared with the same catalyst without any poison and also with previous results obtained from solution impregnation of the same poisons[8][3][9].

    4. Discussion

    The purpose of the work is to study how this procedure of poisoning Co catalyst with aerosol particles will affect catalyst performances during Fischer Tropsch reaction. Previous similar work on Ni catalyst in the SCR reaction using aerosol technology as a method of deposition, has proven loss in metallic surface area, decreasing of metal dispersion and severe reduction in the catalytic activity [7]. The idea is to develop a technique to transfer potassium species, and potentially other relevant impurities, in vapor phase to the catalyst surface. This new approach can to a great extent simulate behaviour during the real industrial process. The aerosol could better represent in situ poisoning and therefore give a more realistic picture of the effect of potassium. This knowledge will be useful for designing new BTL processes.

     

    5. Conclusion

    Aerosol technology was used as a new method for depositing potassium salts on the Co surface. Poisoned catalysts were tested in Fischer Tropsch synthesis reactor together with elemental analysis. Results are compared to the reference catalyst and with previous work which use IWI as poisoning method.

     

     

    6. References

    [1]       A. Norheim, D. Lindberg, J. E. Hustad, and R. Backman, Energy and Fuels, (2009)

    [2]       E. S. Wangen, A. Osatiashtiani, and E. A. Blekkan, Top. Catal., (2011)

    [3]       C. M. Balonek, A. H. Lillebø, S. Rane, E. Rytter, L. D. Schmidt, and A. Holmen, Catal. Letters, (2010)

    [4]       E. A. Blekkan, A. Holmen, S. Vada, Acta Chem. Scand., (1993)

    [5]       J. Gaube and H. F. Klein, Appl. Catal. A Gen., (126–132, 2008)

    [6]       H. M. Westberg, M. Byström, and B. Leckner, Energy and Fuels, (18–28, 2003)

    [7]       S. Albertazzi, F. Basile, J. Brandin, J. Einvall, G. Fornasari, C. Hulteberg, M. Sanati, F. Trifirò, and A. Vaccari, Biomass and Bioenergy, (2008)

    [8]       A. H. Lillebø, E. Patanou, J. Yang, E. A. Blekkan, and A. Holmen, in Catalysis Today, (2013)

    [9]       E. Patanou, A. H. Lillebø, J. Yang, D. Chen, A. Holmen, and E. A. Blekkan, Ind. Eng. Chem. Res., (2014)

    [10]     J. Einvall, S. Albertazzi, C. Hulteberg, A. Malik, F. Basile, A. C. Larsson, J. Brandin, and M. Sanati, Energy and Fuels, (2007)

  • 48.
    Gavrilovic, Ljubisa
    et al.
    Norwegian University of Science and Technology, Norway.
    Blekkan, Edd
    Norwegian University of Science and Technology, Norway.
    Holmen, Anders
    Norwegian University of Science and Technology, Norway.
    Venvik, Hilde
    Norwegian University of Science and Technology, Norway.
    Brandin, Jan
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Fischer-Tropsch Synthesis: Investigation of CO catalyst by exposure to aerosol particles of potassium salts2015In: Norwegian Catalyst Symposium 2015, 2015Conference paper (Refereed)
  • 49.
    Gavrilovic, Ljubisa
    et al.
    Norwegian University of Science and Technology, Norway.
    Brandin, Jan
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Holmen, Anders
    Norwegian University of Science and Technology, Norway.
    Venvik, Hilde
    Norwegian University of Science and Technology, Norway.
    Myrstad, R.
    SINTEF Materials and Chemistry, Norway.
    Blekkan, Edd
    Norwegian University of Science and Technology, Norway.
    Deactivation of Co-based Fischer-Tropsch catalyst by aerosol deposition of potassium salts2018In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 57, no 6, p. 1935-1942Article in journal (Refereed)
    Abstract [en]

    A 20%Co/0.5%Re/γAl2O3 Fischer-Tropsch catalyst was poisoned by four potassium salts (KNO3, K2SO4, KCl, K2CO3) using the aerosol deposition technique, depositing up to 3500 ppm K as solid particles. Standard characterization techniques (H2 Chemisorption, BET, TPR) showed no difference between treated samples and their unpoisoned counterpart. The Fischer-Tropsch activity was investigated at industrially relevant conditions (210 °C, H2:CO = 2:1, 20 bar). The catalytic activity was significantly reduced for samples exposed to potassium, and the loss of activity was more severe with higher potassium loadings, regardless of the potassium salt used. A possible dual deactivation effect by potassium and the counter-ion (chloride, sulfate) is observed with the samples poisoned by KCl and K2SO4. The selectivity towards heavier hydrocarbons (C5+) was slightly increased with increasing potassium loading, while the CH4 selectivity was reduced for all the treated samples. The results support the idea that potassium is mobile under FT conditions. The loss of activity was described by simple deactivation models which imply a strong non-selective poisoning by the potassium species.

  • 50.
    Gavrilovic, Ljubisa
    et al.
    Norwegian University of Science and Technology, Norway.
    Brandin, Jan
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Holmen, Anders
    Norwegian University of Science and technology, Norway .
    Venvik, Hilde
    Norwegan University of Science and technology, Norway.
    Myrstad, Rune
    SINTEF Industry, Norway.
    Blekkan, Edd
    Norwegan University of Science and Technology, Norway.
    Fischer-Tropsch synthesis: Investigation of the deactivation of a Co catalyst by exposure to aerosol particles of potassium salt2018In: Applied Catalysis B: Environmental, ISSN 0926-3373, E-ISSN 1873-3883, Vol. 230, p. 203-209Article in journal (Refereed)
    Abstract [en]

    The influence of potassium species on a Co based Fischer-Tropsch catalyst was investigated using an aerosol deposition technique. This way of poisoning the catalyst was chosen to simulate the actual potassium behaviour during the biomass to liquid (BTL) process utilizing gasification followed by fuel synthesis. A reference catalyst was poisoned with three levels of potassium and the samples were characterized and tested for the Fischer-Tropsch reaction under industrially relevant conditions. None of the conventional characterization techniques applied (H2 Chemisorption, BET, TPR) divulged any difference between poisoned and unpoisoned samples, whereas the activity measurements showed a dramatic drop in activity following potassium deposition. The results are compared to previous results where incipient wetness impregnation was used as the method of potassium deposition. The effect of potassium is quite similar in the two cases, indicating that irrespective of how potassium is introduced it will end up in the same form and on the same location on the active surface. This indicates that potassium is mobile under FTS conditions, and that potassium species are able to migrate to sites of particular relevance for the FT reaction.

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