1. Ash Deposition and Shedding in Biomass Suspension-Fired Boilers
Muhammad S. Bashir
PhD Student ( to )
Supervisors: Kim Dam-Johansen
Peter A. Jensen
Flemming Frandsen
Stig Wedel

2. Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Project Objectives
“Optimal use of Biomass in large suspension-fired boilers.”
Ash deposition and removal behavior in the boiler chamber and superheater region (convective pass).
Transient model based description of key processes responsible for ash deposition and shedding.
Influence of load, operation conditions and fuel mixing on ash deposition and shedding.

3. Ash Deposition during Biomass Combustion
Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Ash Deposition during Biomass Combustion
Biomass (straw)
K, Cl, S
L. Tobiasen et al; Fuel Processing Technology, 88 (2007)

4. Initial Experiments on Amagerværket Unit 2: Co-firing straw and wood
Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Initial Experiments on Amagerværket Unit 2: Co-firing straw and wood
80% Straw

5. Deposit Probe Weight and Heat Uptake
Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Deposit Probe Weight and Heat Uptake
Test No.
1 (SH)
2 (SH)
3 (SH)
4 (SH)
5 (TB)
Straw (%) 35 65 80
100
Wood (%) 20
Flue Gas Temp. (oC)
846
841
851
821
586
Weight Uptake (g/m2)
1080
1410
1480
1700
(20)
Heat Uptake (kW/m2) 22 23 24 10

6. Deposit Characterization for different straw shares
Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Deposit Characterization for different straw shares
35 %
80 %
65 %
100 %

7. Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Ash Enrichment

8. Front Deposits Elemental Composition
Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Front Deposits Elemental Composition

9. Conclusion Deposition rate increases for increase in straw share.
Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Conclusion
Deposition rate increases for increase in straw share.
Deposit layers differ in terms of color, thickness, hardness and composition for change in fuel composition.
Deposits are more sintered in the upper layer for 100% straw-firing.
Deposits and fly ash contains significant amounts of Ca and Si during suspension-firing.

10. Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Final design of vertical probe for ash deposition/shedding in the furnace region.
Modeling of ash deposition/shedding in the furnace region.
Ash deposition/shedding tests at Amagerværket Unit 1 (co-fired with coal) using horizontal sootblowing probe.
Ash deposition/shedding tests at Amagerværket Unit 1 (co-fired with coal) using vertical probe.

11. Tak for opmærksomheden/ Thanks for the Attention !
Objectives Background Experiments Results and Discussion Conclusions Future Work Acknowledgment
Acknowledgment
Dr. Johan Wadenbäck/Søren Thaaning., Vattenfall A/S
Energinet.dk for PSO project funding
Tak for opmærksomheden/
Thanks for the Attention !