Endre søk
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Characterization of particulate matter in the hot product gas from atmospheric fluidized bed biomass gasifiers
Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för teknik, TEK.
2011 (engelsk)Inngår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 35, nr Supplement 1, s. 71-78Artikkel i tidsskrift (Fagfellevurdert) Published
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.

sted, utgiver, år, opplag, sider
2011. Vol. 35, nr Supplement 1, s. 71-78
Emneord [en]
Biomass gasification, particulate matter
HSV kategori
Forskningsprogram
Teknik, Bioenergiteknik/Energi- och Miljöteknik
Identifikatorer
URN: urn:nbn:se:lnu:diva-11263DOI: 10.1016/j.biombioe.2011.02.053Scopus ID: 2-s2.0-80054840488OAI: oai:DiVA.org:lnu-11263DiVA, id: diva2:406907
Tilgjengelig fra: 2011-03-29 Laget: 2011-03-29 Sist oppdatert: 2017-12-11bibliografisk kontrollert
Inngår i avhandling
1. Characterization of particulate matter from atmospheric fluidized bed biomass gasifiers
Åpne denne publikasjonen i ny fane eller vindu >>Characterization of particulate matter from atmospheric fluidized bed biomass gasifiers
2011 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
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.

sted, utgiver, år, opplag, sider
Växjö, Kalmar: Linnaeus University Press, 2011
Serie
Linnaeus University Dissertations ; 50/2011
Emneord
biomass gasification, fluidized bed, particulate matter, particle morphology, particle elementary composition
Forskningsprogram
Teknik, Bioenergiteknik
Identifikatorer
urn:nbn:se:lnu:diva-11473 (URN)978-91-86491-80-2 (ISBN)
Disputas
2011-05-27, Wicksell, Linnéuniversitetet, 351 95 Växjö, Växjö, 10:00 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2011-04-27 Laget: 2011-04-27 Sist oppdatert: 2011-05-02bibliografisk kontrollert
2. Char conversion kinetics and aerosol characterization in biomass gasification
Åpne denne publikasjonen i ny fane eller vindu >>Char conversion kinetics and aerosol characterization in biomass gasification
2013 (engelsk)Doktoravhandling, med artikler (Annet vitenskapelig)
Abstract [en]

Biomass gasification is a thermochemical conversion by partial oxidation at elevated temperature of solid biomass into a gaseous energy carrier. The product gas contains the major components CO, H2, CO2, CH4, as well as some tar and inorganic impurities and solid particles such as ash, bed material, soot and char. The aim of this work is to develop an aerosol-based method to investigate on-line the reactivity of the suspended biomass char particles at high temperatures, and to apply aerosol measurement systems for sampling and characterizing particulate matter in the hot product gas from gasifiers.

An aerosol-based method including the steps for generating, transporting, and oxidizing suspended char particles (0.5–10 µm) was proposed and developed for investigation of char reactivity at high temperatures. An aerodynamic particle sizer (APS) spectrometer was used to measure the particle size distributions. A tapered element oscillating microbalance (TEOM) was used to measure the change of mass concentrations of particles in the carrier gas, before and after conversion. The intrinsic kinetics of various biomass (wood, straw, miscanthus) char particles have been experimentally established in a wide temperature range for both combustion (in air/oxygen) and gasification (in 33 vol% CO2 or 33 vol% steam), up to 800°C and 1300°C, respectively, by combining the aerosol method with thermogravimetric analysis (TGA). The general CO2 or steam gasification reactivity of chars from different biomass could be ranked as wood > miscanthus > straw. In CO2 or steam gasification, the reactivity of char samples measured by the aerosol method at 1300°C would vary by a factor of 4-9 comparing with the extrapolated estimation from the TGA results at the low temperatures. This indicates that high-temperature reactivity estimation by extrapolation should be used with care. Variations of the morphology and the effective density of char particles during conversion indicated that in the initial stage of char conversion (either combustion or gasification), pore growth was dominant up to a certain conversion, and shrinkage or fusing would occur in the later stage. The aerosol-based method presents a set of benefits which are advantageous compared to previously established techniques: no mass transfer limitation at high temperatures; the flexibility to switch to different gas agent combined with continuous feeding of char sample; and the on-line measurement of particle mass and size. The aerosol method is not applicable under the conditions where the reaction rate is slow, since longer residence time will increase the probability of particle losses. In addition to laboratory applications, the aerosol method has potentials for on-line investigation of concentration and reactivity of suspended char fragments sampled directly from the product gas in different types of gasifiers.

Particulate matter (10 nm–10 µm) in the product gas was characterized for the size distribution, morphology and elemental composition by both on-line and off-line techniques. An aerosol particle measurement system including a dilution probe connected in series with a packed activated carbon bed was applied to extract aerosol from the hot product gas produced in the gasifiers using wood as feedstock: an indirect bubbling fluidized bed gasifier and a circulating fluidized bed (CFB) gasifier. The fine and coarse particles from the CFB gasifier contained calcium and magnesium, indicating the contributions from the ash and the magnesite bed material. From the indirect gasifier, the fine-mode (<0.5 µm) particles were dominated by potassium and chlorine whereas the coarse-mode (>0.5 µm) particles were dominated by calcium and silicon, probably from the ash and the bed material. Char fragments were identified in the hot product gas and contribute to the coarse-mode particles in both gasifiers.

 

sted, utgiver, år, opplag, sider
Växjö: Linnaeus University Press, 2013
Serie
Linnaeus University Dissertations ; 150/2013
Emneord
Biomass gasification, fluidized bed, char, kinetics, aerosol, APS, TEOM
HSV kategori
Forskningsprogram
Teknik, Bioenergiteknik/Energi- och Miljöteknik
Identifikatorer
urn:nbn:se:lnu:diva-31347 (URN)978-91-87427-56-5 (ISBN)
Disputas
2013-10-18, M1083, Hus M, Växjö, 10:00 (engelsk)
Opponent
Veileder
Tilgjengelig fra: 2014-02-25 Laget: 2013-12-23 Sist oppdatert: 2014-02-25bibliografisk kontrollert

Open Access i DiVA

Fulltekst mangler i DiVA

Andre lenker

Forlagets fulltekstScopus

Søk i DiVA

Av forfatter/redaktør
Gustafsson, EvaLin, LetengStrand, Michael
Av organisasjonen
I samme tidsskrift
Biomass and Bioenergy

Søk utenfor DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric

doi
urn-nbn
Totalt: 250 treff
RefereraExporteraLink to record
Permanent link

Direct link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf