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  • 1.
    Gustafsson, Eva
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Characterization of particulate matter from atmospheric fluidized bed biomass gasifiers2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Through biomass gasification, biomass can be converted at high temperature to a product gas rich in carbon monoxide, hydrogen, and methane. After cleaning and upgrading, the product gas can be converted to biofuels such as hydrogen; methanol; dimethyl ether; and synthetic diesel, gasoline, and natural gas. Particulate matter (PM) is formed as a contaminant in the gasification process, and the aim of this work was to develop and apply a method for sampling and characterization of PM in the hot product gas.

     

    A particle measurement system consisting of a dilution probe combined in series with a bed of granular activated carbon for tar adsorption was developed, with the aim of extracting a sample of the hot product gas without changing the size distribution and composition of the PM. The mass size distribution and concentration, as well as the morphology and elementary composition, of PM in the size range 10 nm to 10 µm in the product gas from a bubbling fluidized bed (BFB) gasifier, a circulating fluidized bed (CFB) gasifier and an indirect BFB gasifier using various types of biomass as fuel were determined.

     

    All gasifiers and fuels displayed a bimodal particle mass size distribution with a fine mode in the <0.5 µm size range and a coarse mode in the >0.5 µm size range. Compared with the mass concentration of the coarse mode the mass concentration of the fine mode was low from all gasifiers. The evaluation of the results for the fine-mode PM was complicated by condensing potassium chloride for the CFB gasifier when using miscanthus as fuel and by condensing tars for the indirect BFB gasifier when using wood C as fuel. The mass concentration of the coarse-mode PM was higher from the CFB gasifier than from the two BFB gasifiers. The coarse-mode PM from the BFB gasifier when using wood A as fuel was dominated by char. In the CFB gasifier the coarse-mode PM was mainly ash and bed material when using all fuels. The coarse-mode PM from the indirect BFB gasifier when using wood C as fuel was mainly ash.

  • 2.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    Hagberg, Margaretha
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    Att som familj leva i skuggan av demenssjukdom2017In: Att möta familjer inom vård och omsorg / [ed] E. Benzein, M. Hagberg, B-I. Saveman, Lund: Studentlitteratur AB, 2017, 2, p. 179-194Chapter in book (Other academic)
  • 3.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    Hagberg, Margaretha
    Linnaeus University, Faculty of Health and Life Sciences, Department of Health and Caring Sciences.
    "Jag har kvar min Solveig och ändå är hon borta" - utdrag ur en makes dagbok2017In: Att möta familjer inom vård och omsorg / [ed] E. Benzein, M. Hagberg, B-I. Saveman, Lund: Studentlitteratur AB, 2017, 2, p. 165-178Chapter in book (Other academic)
  • 4.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Lin, Leteng
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Seemann, Martin C.
    Rodin, Jennie
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Characterization of Particulate Matter in the Hot Product Gas from Indirect Steam Bubbling Fluidized Bed Gasification of Wood Pellets2011In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 25, no 4, p. 1781-1789Article in journal (Refereed)
    Abstract [en]

    This study characterized the particulate matter (PM) formed during the indirect steam bubbling fluidized bed gasification of wood pellets at atmospheric pressure. A system including a dilution probe, a bed of granular activated carbon, and a thermodenuder was used to sample the PM at high temperature with the aim of separating it from condensing inorganic vapors and tars. The particle mass size distribution was bimodal with a fine mode in the <0.5-μm size range and a dominating coarse mode in the >0.5-μm size range. The coarse mode was representatively characterized while condensing inorganic vapors and tars complicated the evaluation of the results for the fine-mode PM. Morphological analysis of the PM indicated that the char content was low. The inorganic fraction was dominated by potassium and chlorine for fine-mode PM and calcium and silicon for coarse-mode PM.

  • 5.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Lin, Leteng
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Characteristics of aerosol particles from steam and oxygen gasification of various biofuels2010In: 18th European Biomass Conference and Exhibition: From resarch to industry and markets, ETA Renewable Energies and WIP Renewable Energies , 2010, p. 900-902Conference paper (Refereed)
    Abstract [en]

    The present study investigated how the characteristics of the particulate matter (PM) from steam and oxygen gasification of biomass were affected by the biofuel used. The results show that the biofuel had a large impact on the fine mode PM generated during the gasification, both on the particle size distribution and on the elementary composition. When using miscanthus as fuel, high concentrations of ultrafine particles consisting of potassium chloride were formed compared to when using high- and low-quality wood (wood A and wood B) as fuels. The impact of the biofuel on the coarse mode PM was less in this study. Large amounts of bed material dominated the coarse fraction. However, heavy metals were detected in the coarse mode PM when using wood B, constituting treated wood, as fuel.

  • 6.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Lin, Leteng
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Characterization of Particulate Matter from a Circulating Fluidized Bed Gasifier Using Different Types of BiomassManuscript (preprint) (Other academic)
    Abstract [en]

    This study characterized the particulate matter (PM) formed during gasification of different types of biomass in a circulating fluidized bed gasifier at atmospheric pressure. Two systems were used to sample the PM, and both on- and offline analysis techniques were used to characterize the PM. Four different instruments were used to measure the particle mass size distribution and concentration in the size range 0.01–30 µm. The agreement between the instruments was good, and the particle mass size distributions upstream of any cleaning device were bimodal, dominated by the coarse mode (>0.5 µm). The particle mass concentration of the fine mode (<0.5 µm) varied, depending on which biomass was used. The variation in particle mass concentration of the coarse mode was less, and was due to different loads of bed material and various ash contents in the biomass. The morphological analysis of the PM showed that the char content was low and that the PM was dominated by ash and bed material. The coarse-mode PM was rich in magnesium and calcium, while potassium and chlorine were prevalent in the fine-mode PM. The elementary composition of the PM varied between the different types of biomass used and heavy metals, that is, zinc and lead, were detected in low concentrations when using demolition wood as fuel.

  • 7.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Lin, Leteng
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Characterization of particulate matter in the hot product gas from atmospheric fluidized bed biomass gasifiers2011In: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, no Supplement 1, p. 71-78Article in journal (Refereed)
    Abstract [en]

    This study compares the characteristics of particulate matter (PM) in the hot product gas from three different atmospheric fluidized bed biomass gasifiers: a bubbling fluidized bed (BFB) gasifier, a circulating fluidized bed (CFB) gasifier, and an indirect BFB gasifier (the latter integrated with a CFB boiler). All gasifiers displayed a bimodal particle mass size distribution with a fine mode in the <0.5 μm size range and a coarse mode in the >0.5 μm size range. Compared with the mass concentration of the coarse mode the mass concentration of the fine mode was low in all gasifiers. For both the BFB and CFB gasifiers the fine-mode PM had a similar inorganic composition, indicating an origin from the ash and the magnesite bed material used in both gasifiers. In the indirect BFB gasifier the fine-mode PM was instead dominated by potassium and chlorine, and the tar fraction properties evoked tar condensation in the sampling system that affected mainly the fine-mode PM. The coarse-mode PM in the BFB gasifier was dominated by char fragments abraded from the pyrolyzed wood pellets. In the CFB gasifier the coarse-mode PM was mainly ash and magnesite bed material that passed through the process cyclone. In the indirect BFB gasifier the coarse-mode PM was mainly ash, probably originating both from the BFB gasifier and the CFB boiler.

  • 8.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Lin, Leteng
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Simeone, Eleonora
    Technical University of Delft.
    de Jong, Wiebren
    Technical University of Delft.
    Müller, Michael
    Forschungszentrum Jülich.
    Porbatzki, Dirk
    Forschungszentrum Jülich.
    Report of Particle Size and Composition Classificationduring Atmospheric Pressure Gasification2010Report (Other academic)
  • 9.
    Gustafsson, Eva
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergiteknik.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Further development and testing of a method for characterization of particles from biomass gasification using a laboratory scale gasifier2008In: 16th European Biomass Conference & Exhibition: From research to industry and markets, 2008, p. 1037-1040Conference paper (Refereed)
    Abstract [en]

    In the present study, a laboratory scale gasifier was used to further develop and test a method for characterization of particles from biomass gasification. It was found that when an inlet temperature to the bed of activated carbon, used for tar adsorption, of 200ºC was used, particles with low volatility were produced since they vaporized when heated to 300ºC, indicating condensation of tars. When an inlet temperature of 300ºC was used, the particles were stable when heated to 300ºC. This indicates that the tars had been kept in vapour phase and been adsorbed in the carbon bed. The particles were further heated in steps of 100ºC to 700ºC in order to study the change in particle size distribution and total concentration. The particles were stable up to 400ºC, indicating low tar content. The total particle concentration decreased between 400-700ºC probably due to oxidation of carbonaceous material, for example soot, or volatilisation of alkali chlorides. The particles present after heating to 700ºC were most likely inorganic ash. The concentration of fine particles decreased more than the concentration of coarse particles when heated to 700ºC. This could be due to a higher content of carbonaceous material in the fine particles and more ash-rich coarse particles.

  • 10.
    Gustafsson, Eva
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Method for High-Temperature Particle Sampling in Tar-Rich Gases from the Thermochemical Conversion of Biomass2010In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 24, no 3, p. 2042-2051Article in journal (Refereed)
    Abstract [en]

    The thermochemical conversion of biomass produces compounds in both gas and particle phases that may be regarded as contaminants. These contaminants include both particulate matter (e.g., fly ash, soot, and fragmented nonvolatilized material) and volatilized metals and tars that condense and form particulate matter during cooling. In this study a method for high-temperature particle sampling in tar-rich gases from the thermochemical conversion of biomass was developed and tested. Both a bed of granular activated carbon and a denuder were used for tar adsorption. First, the transport efficiency of particles was determined both theoretically and experimentally using a K2SO4 reference aerosol, and the losses were found to be smaller in the denuder than in the bed of granular activated carbon. The adsorption capacity was then tested using a model aerosol of K2SO4 and diethyl-hexyl-sebacate (DEL-IS). The adsorption capacity of the bed of granular activated carbon was found to be higher than that of the denuder. The adsorption capacity was also tested using a model aerosol of K2SO4 particles and tar-rich gas from a laboratory-scale gasifier. As for DEHS, the result indicated that the capacity of the bed of granular activated carbon was higher than that of the denuder; it was also found that the adsorption was incomplete when the tar concentrations increased. In addition, the bed of granular activated carbon was successfully tested during experiments using a 100 kW circulating fluidized bed gasifier. The results indicate that the tar adsorption capacity is dependent not only on the total tar concentration but also on the tar composition

  • 11.
    Gustafsson, Eva
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Strand, Michael
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Sampling of particles from biomass gasification: a method for testing the tar adsorption capacity of a bed ofgranular activated carbon2009In: Book of Proceedings- Bioenergy 2009: Sustainable Bioenergy Business4th International Bioenergy Conference / [ed] Mia Savolainen, Jyväskylä: FINBIO , 2009, p. 645-649Conference paper (Refereed)
    Abstract [en]

    In the present study, a method was developed for testing of the tar adsorption capacity of a bed of granular activated carbon for the application of sampling particles from biomass gasification at high temperature. A laboratory scale gasifier was used to produce a tar-rich gas and sampling was performed using a dilution probe, diluting the gas with either pure nitrogen or nitrogen containing K2SO4 particles. It was found that when using pure nitrogen for dilution; particles were formed using all tested primary dilution ratios; however the concentration decreased when the primary dilution ratio increased. When using nitrogen containing K2SO4 particles for dilution the particle number and volume size distributions were identical with the reference when higher primary dilution ratios were used while particle formation took place when the primary dilution ratio was lower, indicating incomplete tar adsorption. The conclusion of the study was that the method could be used for testing of the tar adsorption capacity of a bed of granular activated carbon for the application of sampling particles from biomass gasification at high temperature and that it is advantageous to use nitrogen containing K2SO4 particles instead of pure nitrogen for dilution in order to facilitate theevaluation of results.

  • 12.
    Gustafsson, Eva
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergi.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Sanati, Mehri
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergi.
    Measurement of Aerosol Particles from Steam and Oxygen Blown Gasification of Wood Pellets in a 20 kW Atmospheric Bubbling Fluidised Bed (ABFB) Gasifier2007In: 15th European Biomass Conference & Exhibition: From Research to Market Deployment, ETA-Renewable Energies and WIP-Renewable Energies , 2007, p. 1128-1130Conference paper (Refereed)
    Abstract [en]

    In the present study, the particle number and mass size distributions from two measurements on steam and oxygen blown atmospheric bubbling fluidised bed (ABFB) gasification (20 kW) of wood pellets are presented. The total particle number concentration determined using a scanning mobility particle sizer (SMPS) varied between 5.1x10^5-6.6x10^6 particles/cm3 (mobility equivalent diameter (dB) 10-670 nm), with the largest variation for particles with dB<100 nm. The particle number size distributions were bimodal with modes at 20-30 nm and at 260-410 nm. The particle mass concentrations determined using a low pressure impactor (LPI) varied between 60-310 mg/m3 for particles with aerodynamic diameter (dae)<5 µm, with modes at 0.2-0.3 µm and at 2-3 µm.

  • 13.
    Gustafsson, Eva
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergi.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Sanati, Mehri
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergi.
    Physical and Chemical Characterization of Aerosol Particles Formed during the Thermochemical Conversion of Wood Pellets Using a Bubbling Fluidized Bed Gasifier2007In: Energy Fuels, ISSN 0887-0624, Vol. 21, no 6, p. 3660-3667Article in journal (Refereed)
    Abstract [en]

    Product gas obtained through biomass gasification can be upgraded to hydrogen-rich synthesis gas. The synthesis gas can be further converted to liquid or gaseous fuels. However, the raw product gas contains both gas- and particle-phase impurities that can negatively affect both catalysts and hot-gas filters used for upgrading and cleaning. The present study aimed to characterize, both physically and chemically, aerosol particles formed during the steam- and oxygen-blown biomass gasification of wood pellets in an atmospheric 20 kW bubbling fluidized bed (BFB) gasifier. The product gas from the gasifier was sampled upstream from the cyclone at 500 °C. The particle number size distribution determined using a scanning mobility particle sizer (SMPS) was bimodal, with modes at 20–30 and 400 nm, mobility equivalent diameters (dB). The total mean number concentration of particles with dB = 15–670 nm was approximately 7 × 10^5 particles/cm3; however, the concentration of particles with dB < 80 nm fluctuated. The particle mass size distribution determined using a low-pressure impactor (LPI) was bimodal, and the total mass concentration of particles with aerodynamic diameters (dae) < 5 µm was 310 mg/m3. Microscopy analysis of particulate matter on the lower LPI stages, expected to sample particles with dae < 0.4 µm, revealed structures approximately 10 µm in diameter. In addition, the mass concentration of particles with dae < 0.5 µm determined using a LPI was higher than that estimated using a SMPS, possibly because of the bounce-off or re-entrainment of coarser particles from higher LPI stages. Elementary analysis of the particulate matter indicated that it was dominated by carbon. The collected particulate matter was stable when heated in nitrogen to 500 °C, indicating that the carbon was not present as volatile tars but more likely as char or soot. The particulate matter collected on all LPI stages contained a small percentage of ash (noncarbonaceous inorganic material), with calcium as the dominant element.

  • 14.
    Lin, Leteng
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustafsson, Eva
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Aerosol-based method for investigating biomass char reactivity at high temperatures2011In: Combustion and Flame, ISSN 0010-2180, E-ISSN 1556-2921, Vol. 158, no 7, p. 1426-1437Article in journal (Refereed)
    Abstract [en]

    An aerosol-based method was proposed and developed to characterize particles fragmented from biomass chars during oxidation. The chars were prepared from both wood and miscanthus pellets under various pyrolysis conditions. Char fragments with aerodynamic diameters in the range of 0.5–10 μm were suspended and transported in a reactive gas through an aerosol reactor, which was heated by an electric oven. The oxidation of char particles in the reactor was investigated by determining on-line the particle size distributions before and after passage through the reactor using an aerodynamic particle sizer (APS) spectrometer. The interpretation of APS data was evaluated by both experiments and models in which the fine char particles were assumed to keep either constant density or constant diameter during the oxidation process. The results indicate that the aerosol-based method can be used to determine reaction kinetics of char particles in the high temperature range, where oxidation is normally controlled by diffusion limitation if measuring with the conventional techniques. The application of the aerosol method indicated that high pyrolysis temperature and prolonged retention time will reduce the char reactivity.

  • 15.
    Lin, Leteng
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustafsson, Eva
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Strand, Michael
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    High-temperature Kinetics of Fine Biomass Char Particles in Air and CO22010In: 18th European Biomass Conference and Exhibition: From Research to Industry and Markets, 2010Conference paper (Refereed)
    Abstract [en]

    Knowledge of reliable chemical kinetics of char always plays significant roles in the modelling, design and optimization of processes during biofuel thermochemical conversions.The determination of reaction kinetics of char in the high-temperature range still highly depends on the extrapolation of results from kinetic data determined at lower temperatures due to mass and heat transfer limitations. In this work an aerosol-based method was used to investigate the reactivity of singly-distributed char particles with aerodynamic diameters between 0.5-10 mm. The conversion of char particles in the reactor at varying temperatures and residence time was determined by comparing the particle size distributions before and after passing the reactor, using an aerodynamic particle sizer (APS) spectrometer. The results of char particles reacted with air, CO2 and steam indicate that the aerosol-based method can be used to determine reaction kinetics of char particles in the high temperature range where reaction is controlled by diffusion limitation if using conventional thermogravimetric analysis (TGA). By combining the aerosol-based method and conventional TGA, the oxidation and gasification kinetic parameters of biomass char can be derived in the temperature range of 350-800ºC, and 800-1200ºC respectively. The aerosol-based method shows the potential of on-line measuring the char reactivity.

  • 16.
    Strand, Michael
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustafsson, Eva
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Final Report on the Recommended General Design andDevelopment of Gas and Aerosol Particle Sampling Probes2010Report (Other academic)
  • 17.
    Strand, Michael
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustafsson, Eva
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Lin, Leteng
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Yang, Jingjing
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    High-Temperature extraction of aerosol particles from biomass combustion and gasification2011In: European Aerosol Conference 2011, 2011Conference paper (Refereed)
1 - 17 of 17
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