umu.sePublications
Change search
ReferencesLink to record
Permanent link

Direct link
Mechanism of Quartz Bed Particle Layer Formation in Fluidized Bed Combustion of Wood-Derived Fuels
Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
Show others and affiliations
2016 (English)In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 30, no 3, 2227-2232 p.Article in journal (Refereed) PublishedText
Abstract [en]

Agglomeration is among one of the major problems in the operation of fluidized bed boilers. The formation of bed particle layers is thought to play an important role on the occurrence of agglomeration in wood-fired fluidized (quartz) beds. In spite of frequent experimental reports on the quartz bed particle layer characteristics, the underlying bed layer formation process has not yet been presented. By combining our previously experimental results on layer characteristics for samples with durations from 4 h to 23 days, with phase diagrams, thermochemical equilibrium calculations, and a diffusion model, a mechanism of quartz bed particle layer formation was proposed. For younger bed particles (<around 1 day), the layer growth process is accelerated due to a high diffusion of calcium in a K-rich silicate melt. However, with continuous addition of calcium into the layer, the amount of melt decreases and crystalline Ca-silicates starts to form. Ca2SiO4 is the dominating crystalline phase in the inner layer, while the formation of CaSiO3 and possibly Ca3SiO5 are favored for younger and older bed particles, respectively. The decreasing amount of melt and formation of crystalline phases result in low diffusion rates of calcium in the inner layer and the layer growth process becomes diffusion controlled after around 1 day.

Place, publisher, year, edition, pages
2016. Vol. 30, no 3, 2227-2232 p.
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:umu:diva-119290DOI: 10.1021/acs.energyfuels.5b02891ISI: 000372562800078OAI: oai:DiVA.org:umu-119290DiVA: diva2:921661
Available from: 2016-04-20 Created: 2016-04-15 Last updated: 2016-04-20Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Boström, DanBackman, Rainer
By organisation
Department of Applied Physics and Electronics
In the same journal
Energy & Fuels
Physical Chemistry

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 27 hits
ReferencesLink to record
Permanent link

Direct link