750 NITROGEN OXIDES REDUCTION
allowable NO x emission at 15% O 2 , dry is given by the
following equations:(^)
E
Y
n=+0 0150 F.
14 4
.
(.)
where
E n NOx limit (% by volume, dry)
Y mfg.’s rated heat rate at mfg.’s rated peak load or
the actual measured heat rate based on lower heating
value of fuel as measured at actual peak load for the
facility. The value of Y shall not exceed 14.4 kJ per
watt hour.
F defined according to the nitrogen content of the
fuel as follows:
Fuel-bound nitrogen (% by weight) F (NOx % by volume)
N 0.015 0
0.015 N 0.1 0.04 (N)
0.1 N 0.25 0.004 0.0067 (N-0.1)
N > 0.25 0.005
In addition to NSPS and NAAQS, the USEPA is reduc-
ing NO x emissions through Title IV, the Acid Rain Program.
The regulations under this program were published as final
in the April 13, 1995 Federal Register and became effective
on May 23, 1995. The regulations are aimed directly at coal
fired utility plants in which the combustion of coal on a BTU
basis exceeds 50% of its annual heat input. The type of boil-
ers used at these plants has been subdivided into Group 1
and Group 2 boilers. Group 1 boilers include tangentially
fired boilers or dry bottom wall-fired boilers. Group 2
boilers include wet bottom wall-fired boilers, cyclone boil-
ers, vertically fired boilers, arch-fired boilers, or utility boilers
(i.e. fluidized bed or stoker boilers). In addition, the CAA
has set standards based on Phase I and Phase II.
In the acid rain regulations, NO x emission limits have been
established for Phase I coal fired utility units with tangentially
fired boilers (95 units) or with dry bottom wall-fired boilers
(84 units), which were to be effective January 1, 1996. For tan-
gentially fired boilers, the limit is 0.45 lb/MBtu of heat input on
an annual average basis. For dry bottom wall fired boilers, the
NO x limit is 0.50 lb/MBtu of heat input expressed on an annual
average basis. The facilities that cannot meet the requirements
will be allowed to apply for a less restrictive emission standard
or to join an “averaging pool,” through which the overall emis-
sions limit average is attained. Phase I standards for Group 2
boilers are scheduled to be set by January 1, 1997 with imple-
mentation by January 1, 2000. Phase II standards for Group 1
and 2 boilers are required to be established by 1997.^11
Similar to the federal government under the Clean Air Act,
State governments have the authorization to enact regulations
that maintain ambient air quality and to set limits for sources
of air pollution. In New York State, the agency charged with
TABLE 2^
USEPA 40 CFR Part 60 Subpart Da-electric utility steam generating units NO x emission limits^10
Emission limit for heat input
Fuel type ng/J (lb NOx/MBtu)
Gaseous fuels
Coal-derived fuels 210 0.50
All other fuels 86 0.20
Liquid fuels
Coal-derived fuels 210 0.50
Shale oil 210 0.50
All other fuels 130 0.30
Solid fuels
Coal-derived fuels 210 0.50
Any fuel containing more than 25%, by weight, coal refuse^1 (^1 )(^1 )
Any fuel containing more than 25%, by weight, lignite if the lignite
is mined in North Dakota, South Dakota, or Montana, and is
combusted in a slag tap furnace^2
340 0.80
Any fuel containing more than 25%, by weight, lignite not subject
to the 340 ng/J heat input emissions limit^2
260 0.60
Subbituminous coal 210 0.50
Bituminous coal 260 0.60
Anthracite coal 260 0.60
All other fuels 260 0.60
1 Exempt from NO x standards and NO x monitoring requirements.
2 Any fuel containing less than 25%, by weight, lignite is not prorated but its % is added to the % of the
predominant fuel.
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