GE P&W FuelSolv - Opportunity Coal Slag Control at Lakeland McIntosh Unit #3 - Manual (Page 8)

Page 8 Technical Paper
Figure 16: Burner Level, Floor 5.5 Port A (5-26-11)
Impact to Balance of Plant
Prior to the trial, the chemical additives were re-
viewed to determine if they would impact other
plant operations, such as Selective Catalytic Reduc-
tion (SCR), Electrostatic Precipitator (ESP) or Wet Flue
Gas Desulfurization System (Wet FGD) performance
for NOx, particulate and SO
2
emissions, respectively.
In addition, the metal oxide product was reviewed
for impact to flyash or wastewater discharge per-
mitting. During the trial Lakeland Operations con-
tinued to monitor the flue gas train and balance of
plant, and it was determined that the products did
not adversely impact the plant.
There were several beneficial results of the trial be-
sides slag mitigation. Lakeland’s daily flyash lab
testing indicated an increase in alkalinity and a de-
crease in Loss On Ignition (LOI) during the periods of
time where the product was being dosed to the
coal. This is believed to be attributed to the metal
oxide’s role as a combustion catalyst in addition to
the primary role as slag reducer. The three trial pe-
riods are highlighted in Figure 17. The second phase
(8/4-8/21) firing 25% CAPP / 75% ILB strongly indi-
cates LOI improved during the trial. Longer runs
and a more thorough statistical analysis is required
to definitively claim LOI improvement. Since Lake-
land sells their flyash for cement production, among
other uses, a low LOI brings value to the end-user
and appears to be a co-benefit of the slag mitiga-
tion program.
2.0
2.5
3.0
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2011
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/2
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/2
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2011
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/20
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Lakeland McIntosh Unit 3 - ESP Fly Ash LOI's
Figure 17: McIntosh Unit 3 LOI values during 2011
Trial Results and Conclusions
The two-product approach of magnesium and
metal oxide slurries allowed Lakeland the flexibility
to evaluate a wide range of opportunity coals for
their system. The magnesium-based product in
conjunction with metal oxide slurry maintained
relatively slag-free boiler even at high opportunity
coal ratios (75%). Higher opportunity coal blends
could be evaluated with SO
3
-remediation systems
in place.
The visual observations and operator feedback
indicated that the synergistic combination of the
1.5-lb magnesium-based product range per ton of
NAPP coal in conjunction with 0.25-lb metal oxide-
based product per ton of opportunity coal was
very effective in mitigating slag of the blended
fuel. Different coals or coal blends may require
customized product ratios to appropriately ad-
dress potential slagging issues.
Because delayed coal deliveries affected the trial
schedule, chemical dosage was not able to be op-
timized during these short trial durations. GE
looks forward to working with Lakeland Electric to
evaluate other Northern Appalachian and Illinois
Basin opportunity fuels to achieve lowest dosage
of products to minimize total treatment costs.
Economic Forecasts
Lakeland’s estimates for fuel cost savings are sig-
nificant: $3-4 million in cost savings could easily
be achieved in 2012, as reported by The Ledger.
(Chambliss, 2011) At full load, McIntosh fires 3,000
tons of coal per day. Firing 100% CAPP at $100
per ton (delivered), annual fuel cost estimate is
approximately $110 million.