Deposition Properties of Biomass Fly Ash

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Abstract

This study investigated deposit formation of biomass fly ash on steel tubes, in a lab-scale Entrained Flow Reactor. Experiments were conducted using model biomass fly ash, prepared from mixtures of K2Si4O9, KCl, K2SO4, CaO, SiO2 and KOH, as well as three different boiler fly ashes: a wood fly ash, a straw fly ash, and a straw + wood cofired fly ash. The fly ashes were injected into the reactor, to form deposits on an air-cooled deposit probe, simulating deposit formation on superheater tubes in boilers. The results revealed that increasing flue gas temperature, probe surface temperature, time, fly ash flux and fly ash particle size increased the rate of deposit formation. However, increasing flue gas velocity resulted in a decrease in the deposit formation rate. A mechanistic model was developed for predicting deposit formation in the reactor. Inertial impaction was the primary mechanism of deposit formation, when pure K2Si4O9, SiO2 or CaO was injected into the reactor, forming deposits only on the upstream side of the steel tube. However, feeding KCl, K2SO4 or KOH into the reactor resulted in deposit formation on both sides of the steel tube, via condensation, thermophoresis, and inertial impaction
Original languageEnglish
Title of host publicationProceedings of 26th European Biomass Conference and Exhibition
Volume2018
PublisherETA-Florence Renewable Energies
Publication date2018
Pages440-452
Article number2AO.8.2
ISBN (Electronic)978-88-89407-18-9
DOIs
Publication statusPublished - 2018
Event26th European Biomass Conference and Exhibition (EUBCE 2018) - Bella Center, Copenhagen, Denmark
Duration: 14 May 201817 May 2018

Conference

Conference26th European Biomass Conference and Exhibition (EUBCE 2018)
LocationBella Center
CountryDenmark
CityCopenhagen
Period14/05/201817/05/2018
SeriesProceedings of European Biomass Conference and Exhibition
Volume2018
ISSN2282-5819

Keywords

  • Biomass
  • Fly ash
  • Deposit formation
  • Fouling
  • Ash sticking probability
  • Entrained flow reactor

Cite this

Laxminarayan, Y., Jensen, P. A., Wang, G., Wu, H., Sander, B., Frandsen, F. J., & Glarborg, P. (2018). Deposition Properties of Biomass Fly Ash. In Proceedings of 26th European Biomass Conference and Exhibition (Vol. 2018, pp. 440-452). [2AO.8.2] ETA-Florence Renewable Energies. Proceedings of European Biomass Conference and Exhibition, Vol.. 2018 https://doi.org/10.5071/26thEUBCE2018-2AO.8.2