SwePub
Sök i LIBRIS databas

  Extended search

id:"swepub:oai:DiVA.org:umu-60947"
 

Search: id:"swepub:oai:DiVA.org:umu-60947" > Bed agglomeration c...

  • 1 of 1
  • Previous record
  • Next record
  •    To hitlist

Bed agglomeration characteristics in fluidized quartz bed combustion of phosphorus-rich biomass fuels

Grimm, Alejandro (author)
Luleå tekniska universitet,Energivetenskap
Skoglund, Nils, 1979- (author)
Umeå universitet,Energiteknik och termisk processkemi,Thermochemical Energy Conversion Laboratory,Umeå university
Boström, Dan (author)
Umeå universitet,Energiteknik och termisk processkemi,Umeå university
show more...
Öhman, Marcus (author)
Luleå tekniska universitet,Energivetenskap
show less...
 (creator_code:org_t)
2011-02-20
2011
English.
In: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 25:3, s. 937-947
  • Journal article (peer-reviewed)
Abstract Subject headings
Close  
  • The bed agglomeration characteristics during combustion of phosphorus-rich biomass fuels and fuel mixtures were determined in a fluidized (quartz) bed reactor (5 kW). The fuels studied (separately and in mixtures) included logging residues, bark, willow, wheat straw, and phosphorus-rich fuels, like rapeseed meal (RM) and wheat distillers dried grain with solubles (DDGS). Phosphoric acid was used as a fuel additive. Bed material samples and agglomerates were studied by means of scanning electron microscopy (SEM) in combination with energy-dispersive X-ray spectroscopy (EDX), in order to analyze the morphological and compositional changes of coating/reaction layers and necks between agglomerated bed particles. Furthermore, bed ash particles were separated by sieving from the bed material samples and analyzed with SEM/EDS and powder X-ray diffraction (XRD). For logging residues, bark, and willow, with fuel ash rich in Ca and K but with low contents of P and organically bound Si, the bed layer formation is initiated by reactions of gaseous or liquid K compounds with the surface of the bed material grains, resulting in the formation of a potassium silicate melt. The last process is accompanied by the diffusion/dissolving of Ca into the melt and consequent viscous flow sintering and agglomeration. The addition of high enough phosphorus content to convert the available fuel ash basic oxides into phosphates reduced the amount of K available for the reaction with the quartz bed material grains, thus preventing the formation of an inner bed particle layer in the combustion of logging residues, bark, and willow. Some of the phosphate-rich ash particles, formed during the fuel conversion, adhered and reacted with the bed material grains to form noncontinuous phosphate−silicate coating layers, which were found responsible for the agglomeration process. Adding phosphorus-rich fuels/additives to fuels rich in K and Si (e.g., wheat straw) leads to the formation of alkali-rich phosphate−silicate ash particles that also adhered to the bed particles and caused agglomeration. The melting behavior of the bed particle layers/coatings formed during combustion of phosphorus-rich fuels and fuel mixtures is an important controlling factor behind the agglomeration tendency of the fuel and is heavily dependent on the content of alkaline earth metals in the fuel. A general observation is that phosphorus is the controlling element in ash transformation reactions during biomass combustion in fluidized quartz beds because of the high stability of phosphate compounds.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)
ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)
NATURVETENSKAP  -- Kemi -- Oorganisk kemi (hsv//swe)
NATURAL SCIENCES  -- Chemical Sciences -- Inorganic Chemistry (hsv//eng)
TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Energiteknik (hsv//swe)
ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Energy Engineering (hsv//eng)

Keyword

Inorganic Chemistry
oorganisk kemi
Energy Engineering

Publication and Content Type

ref (subject category)
art (subject category)

Find in a library

To the university's database

  • 1 of 1
  • Previous record
  • Next record
  •    To hitlist

Search outside SwePub

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Close

Copy and save the link in order to return to this view