EC-3
What is the difference in NO and NO
2
in stack
gases?
Nitric oxide (NO) and Nitrogen Dioxide (NO
2
) are the
toxic gases which constitute NO
X
. All combustion
processes can produce NO
X
.
NO
X
emissions contribute to the formation of acids in
the earth’s lower atmosphere; these acids contribute to
the formation of acid rain.
Additionally, NO
X
and hydrocarbons can react with
sunlight to produce a potent respiratory irritant that is
commonly called smog.
NO
X
from combustion comes from three different
sources: thermal NO
X
, prompt NO
X
and fuel bound
NO
X
.
In boilers or furnaces which burn fuels low in nitrogen
(gas and light oils), thermal NO
X
predominates. When
fossil fuels rich in nitrogen (heavy oils) are burned, high-
er concentrations of fuel NO
X
are generated.
Prompt NO
X
is a small amount of total NO
X
emissions
that occur during low temperature stages of combus-
tion.
Typically, Nitric Oxide (NO) comprises over 95% of the
NO
X
found in stack gases. However, a significant
amount of NO converts to NO
2
in the atmosphere.
Because NO and NO
2
combine to form NO
X
, which
contributes to smog and acid rain, legislation to reduce
and control these emissions has become much tougher.
EC-4
Where do I get information about specific
e n v i ronmental combustion regulations that
could affect my organization?
The best source of information is your local or regional
EPA and DER office. You can find them listed in the tele-
phone directory.
EC-5
What is the Clean Air Act and does it apply to
everyone with a furnace or boiler?
The Clean Air Act of 1970, including the amendments
made in 1990, is a federal law which was created to
reduce air pollution (smog), acid rain and other air pol-
lutants which have been identified as toxic emissions.
The Act itself is 868 pages in length and encompasses
v i rtually every conceivable form of air pollution, air pollu-
tion abatement programs and even re q u i res that methods
used in testing, for example SO
2
, meet legislated criteria.
Some of the provisions of The Clean Air Act are :
- S O
2
emissions from utilities reduced by 50%.
- 189 toxic substances will be measured by peer
re v i e w.
- Five year federal operating permits to be issued.
- EPS continues to develop federal regulations to
assure compliance.
The 1990 amendments to the Federal Clean Air Act of
1970 have established a dramatically different air toxins
program.
This Act requires the EPA to establish operational and
monitoring guidelines for industrial and commercial
boilers and empowers state and local authorities to
enforce the regulations.
These new regulations will affect combustion processes
in facilities as diverse as large petrochemical plants and
small local schools; regulatory compliance will become
commonplace for nearly every industry, company and
institution.
Already the South Coast Air Quality Management
District (SCAQMD) in Southern California has developed
its own legislation that will enforce the EPA guidelines.
Rule 1146 requires that boilers over 2 million BTU per
hour in capacity operate with NO
X
emissions of less
than 40 ppm. To meet these stringent requirements,
routine testing of stack gases for NO
X
and other com-
bustion by-products is legislatively mandated in
Southern California. Using the SCAQMD as a model,
other states and regions are developing similar regula-
tory programs across the United States.
I n t e rn a t i o n a l l y, the re
g u l a t o ry climate is becoming
much tougher. Germany has passed legislation which
mandates the NO
X
testing of residential furnaces.
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