Combustion of biomass in jet flames

Weber, Roman; Poyraz, Yunus; Beckmann, An Marcel; Brinker, Stefan

doi:10.1016/j.proci.2014.06.033

Cited by 34 publications

(16 citation statements)

References 16 publications

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“…On the other hand, the overall particle sticking efficiency for coal has a value of about 0.8, which was approximately twice that of the values (about 0.4) for biomass. It is interesting that the values of the sticking efficiency in this study are comparable to those presented by Weber et al [41], which are approximately 0.8 and 0.4 for the coal and mixed wood under a similar furnace velocity.…”

Section: Measured and Predicted Ash Deposition Behavioursupporting

confidence: 88%

“…However, the predicted impaction efficiency by Weber et al [41] is much higher than in the current study. This discrepancy can be attributed to the particle size of the fly ash being assumed to be constant during combustion process by Weber et al [41] while the fly ash size is assumed to be reduced based on the ash content in this study. On the other hand, the overall particle sticking efficiency for coal has a value of about 0.8, which was approximately twice that of the values (about 0.4) for biomass.…”

Section: Measured and Predicted Ash Deposition Behaviourcontrasting

confidence: 82%

“…This is mainly due to the overall particle impaction efficiency for coal, ranging from 1.5% to 6.4%, being much lower than the recycled wood, ranging from 8.6 to 15.4% and 6.6% to 12.1% for air combustion and oxyfuel combustion, respectively, as shown in Figure 3(c). Weber et al [41] also found that biomass fuels have a much higher deposition rate and particle impaction efficiency than the South African Middleburg coal. However, the predicted impaction efficiency by Weber et al [41] is much higher than in the current study.…”

Section: Measured and Predicted Ash Deposition Behaviourmentioning

confidence: 98%

“…Weber et al [41] also found that biomass fuels have a much higher deposition rate and particle impaction efficiency than the South African Middleburg coal. However, the predicted impaction efficiency by Weber et al [41] is much higher than in the current study. This discrepancy can be attributed to the particle size of the fly ash being assumed to be constant during combustion process by Weber et al [41] while the fly ash size is assumed to be reduced based on the ash content in this study.…”

Section: Measured and Predicted Ash Deposition Behaviourmentioning

confidence: 98%

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Understanding the effects of oxyfuel combustion and furnace scale on biomass ash deposition

Yang

Szuhánszki

Tian

et al. 2019

Fuel

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Recycled wood oxyfuel combustion is attractive for the advantages of reusing the waste bioenergy and reducing the carbon emissions. However, the changes in the fuel properties and combustion conditions can lead to uncertainties in the ash deposition. In addition, the understanding of the differences in the ash deposition between the pilot-scale and full-scale furnaces is very limited. We have performed ash deposition experiments on a 250 kW pilot-scale furnace for recycled wood air and oxyfuel combustion along with the EI Cerrejon coal combustion as a reference. A CFD-based ash deposition model, which uses the excess energy based particle sticking model, has been developed and the predictions are in qualitative agreement with the measurement data. The results suggest that, besides furnace temperature, the aerodynamics and ash physicochemical properties dictate the ash deposition. The recycled wood has a much higher deposition rate than the coal in the pilot-scale furnace; however, the biomass can numerically have a lower deposition rate under high velocities close to the full-scale boilers. This is mainly due to the biomass having a much lower sticking efficiency since it has high calcium and silicon concentrations and low potassium concentration. Although the effect of oxyfuel combustion is small and within the experimental uncertainties, it is found that oxyfuel combustion can affect the particle impaction and sticking behaviours depending on the fly ash properties and these effects occur in different ways in the pilot-scale and full-scale conditions. Great care should be taken to perform the transfer of the deposition observations from the pilot scale to the full scale and this is because the furnace scale has an effect on the selective deposition behaviour. In this paper a relationship between the fly ash properties (ash composition, size, etc.) and ash deposition for the woody biomass has been proposed.

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Section: Measured and Predicted Ash Deposition Behavioursupporting

confidence: 88%

Section: Measured and Predicted Ash Deposition Behaviourcontrasting

confidence: 82%

Section: Measured and Predicted Ash Deposition Behaviourmentioning

confidence: 98%

Section: Measured and Predicted Ash Deposition Behaviourmentioning

confidence: 98%

See 2 more Smart Citations

Understanding the effects of oxyfuel combustion and furnace scale on biomass ash deposition

Yang

Szuhánszki

Tian

et al. 2019

Fuel

View full text Add to dashboard Cite

show abstract

“…Therefore, relevant viscosity data will be investigated while missing data will be measured by high temperature rotational viscosimetry. The viscosity data, as well as the phase diagrams concerning bio-ashes, are needed to determine the sticking efficiency of ash particles impacting on the wall either through applying a viscosity criterion or a melting fraction criterion [77]. Such criteria are essential in developing a slag sub-model (see Sections 2.3 and 2.5).…”

Section: Modelling Slag Propertiesmentioning

confidence: 99%