Deposit Shedding in Biomass-Fired Boilers: Shear Adhesion Strength Measurements

Laxminarayan, Yashasvi; Jensen, Peter Arendt; Wu, Hao; Frandsen, Flemming; Sander, Bo; Glarborg, Peter

doi:10.1021/acs.energyfuels.7b01312

Cited by 18 publications

(38 citation statements)

References 54 publications

(123 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A video of deposit formation and shedding on the steel tube can be found in the supplemental material (Video S1), or accessed at youtu.be/gLSHd8fAZo0. The results concur with previous investigations [12,23], establishing debonding as the dominant mechanism of deposit shedding in boilers.…”

Section: Effect Of Probe Residence Timesupporting

confidence: 92%

“…Visual observations of the formed deposits (see The experimental results agree with full-scale investigations [9], where increasing flue gas temperatures led to increased deposit formation. Furthermore, it was observed that increasing the flue gas temperature in the experiments resulted in increased adhesion strength of the deposits to the steel tube, as indicated by previous studies [23]. Deposit shedding was not observed in any of the reported experiments.…”

Section: Effect Of Flue Gas Temperaturesupporting

confidence: 73%

“…However, it should be noted that fly ash in boilers typically forms a bimodal particle size distribution, containing submicron particles, as well as larger particles [3]. K2Si4O9 was subjected to Differential Scanning Calorimetry (DSC), revealing that K2Si4O9 forms a glass phase at 650 °C, after which the viscosity of K2Si4O9 decreases with increasing temperature [23].…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Biomass fly ash deposition in an entrained flow reactor

Laxminarayan

Jensen

et al. 2019

Proceedings of the Combustion Institute

Self Cite

View full text Add to dashboard Cite

Fly ash deposition on boiler surfaces is a major operational problem encountered in biomass-fired boilers. Understanding deposit formation, and developing modelling tools, will allow improvements in boiler efficiency and availability. In this study, deposit formation of a model biomass ash species (K2Si4O9) on steel tubes, was investigated in a lab-scale Entrained Flow Reactor. K2Si4O9 was injected into the reactor, to form deposits on an air-cooled probe, simulating deposit formation on superheater tubes in boilers. The influence of flue gas temperature (589-968 °C), probe surface temperature (300-550 °C), flue gas velocity (0.7-3.5 m/s), fly ash flux (10000-40000 g/m 2 h), and probe residence time (up to 60 min) was investigated. The results revealed that increasing flue gas temperature and probe surface temperature increased the sticking probability of the fly ash particles, thereby increasing the rate of deposit formation. However, increasing flue gas velocity resulted in a decrease in the deposit formation rate, due to increased particle rebound. Furthermore, the deposit formation rate increased with probe residence time and fly ash flux. Inertial impaction was the primary mechanism of deposit formation, forming deposits only on the upstream side of the steel tube. A mechanistic model was developed for predicting deposit formation in the reactor. Deposit formation by thermophoresis and inertial impaction was incorporated into the model, and the sticking probability of the ash particles was estimated by accounting for energy dissipation due to particle deformation. The model reasonably predicted the influence of flue gas temperature and fly ash flux on the deposit formation rate.

show abstract

Section: Effect Of Probe Residence Timesupporting

confidence: 92%

Section: Effect Of Flue Gas Temperaturesupporting

confidence: 73%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Biomass fly ash deposition in an entrained flow reactor

Laxminarayan

Jensen

et al. 2019

Proceedings of the Combustion Institute

Self Cite

View full text Add to dashboard Cite

show abstract

“…1,2 Combustion of biomass in suspension-fired boilers can produce renewable, CO 2 -neutral electricity with a higher electrical efficiency compared with that of grate-fired boilers. 3 However, during the combustion process of biomass, significant amounts of Kspecies, such as KOH, KCl and K 2 SO 4 , are released to gas phase in the boiler chamber, and this leads to deposit formation, corrosion [4][5][6][7][8][9][10][11][12] as well as de-activation of SCR (Selective Catalytic Reduction) catalysts. [13][14][15][16][17][18] Ash deposition and corrosion problems may be mitigated by reducing the super heater temperature.…”

Section: Introductionmentioning

confidence: 99%

Potassium Capture by Kaolin, Part 1: KOH

Wang¹,

Jensen²,

Wu³

et al. 2018

Energy Fuels

Self Cite

View full text Add to dashboard Cite

 Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

show abstract

“…Biomass suspension-combustion has a higher electrical efficiency and higher load-flexibility compared to traditional grate-fired boilers, but the ash-related problems, including deposition, corrosion and SCR catalyst deactivation, may be more severe [1] than that in grate-fired boilers [2][3][4][5][6][7][8][9][10], due to a higher concentration of fly ash in the flue gas [6]. Potassium originating from biomass is the primary cause for the ash-related problems.…”

Section: Introductionmentioning

confidence: 99%