With gas reburning, the differential cost
of gas over coal is the largest component
of the cost of NOx reduction. When coal
is used as the reburn fuel, this differential
is zero. Thus, coal reburning has the potential
for significantly lower NOx control
cost than gas reburning. The challenge
with coal reburning is to achieve aequate
combustion of the reburn coal in the oxygen
deficient, short residence time reburn
zone. This project demonstrates micronized
coal reburning, where the reburn coal
is finely ground to 85% below 325 mesh.
The small coal particles have greatly
increased surface area which increases
the rate of combustion, allowing coal
1.0
0.8
0.7
0.4
0.2
0
2.0 3.0 4.0 5.0 6.0
GR-LNB
140-160 MWe (Net)
9-15% Gas
LNB
Baseline
NOx (lb/10
6 Btu)
Excess O2 (% dry)
NOx reduction data from Cherokee Station.
Kodak Park.
Milliken Station, located in the Finger
reburning to be applied in units with lim- Lakes Region of New York State.
ited reburn zone residence time