Page 112 - Fundamentals of Air Pollution

82 6. Sources of Air Pollution

TABLE 6-1
Comparison of Combustion Pollutants"
Uncontrolled
Power plant Refuse burning automotive
emission emission emission
(gm/kg fuel) (gm/kg refuse) (gm/kg fuel)
Open Multiple
Contaminant Coal Oil Gas burning chamber Gasoline Diesel
Carbon monoxide Nil Nil Nil 50.0 Nil 165.0 Nil
Oxides of sulfur (SO 2) (20)x (20)* (16)* 1.5 1.0 0.8 7.5
Oxides of nitrogen (NO 2) 0.43 0.68 0.16 2.0 1.0 16.5 16.5
Aldehydes and ketones Nil 0.003 0.001 3.0 0.5 0.8 1.6
Total hydrocarbons 0.43 0.05 0.005 7.5 0.5 33.0 30.0
Total particulate (75)y (2.% Nil 11 11 0.05 18.0
" x - percentage of sulfur in fuel; y = percentage of ash in fuel.

method used to control the emissions from steel mill X may be applied to
control similar emissions at plant Y. It should not be necessary for plant
Y to spend excessive amounts for research and development if plant X has
a system that is operating satisfactorily. The solution to the problem is
often to look for a similar industrial process, with similar emissions, and
find the type of control system used.

A. Chemical and Allied Products
The emissions from a chemical process can be related to the specific
process. A plant manufacturing a resin might be expected to emit not only
the resin being manufactured but also some of the raw material and some
other products which may or may not resemble the resin. A plant manufac-
turing sulfuric acid can be expected to emit sulfuric acid fumes and SO 2 .
A plant manufacturing soap products could be expected to emit a variety
of odors. Depending on the process, the emissions could be any one or a
combination of dust, aerosols, fumes, or gases. The emissions may or may
not be odorous or toxic. Some of the primary emissions might be innocuous
but later react in the atmosphere to form an undesirable secondary pollut-
ant. A flowchart and material balance sheet for the particular process
are very helpful in understanding and analyzing any process and its emis-
sions (6).
In any discussion of the importance of emissions from a particular process
for an area, several factors must be considered—(1) the percentage of the
total emissions of the area that the particular process emits, (2) the degree
of toxicity of the emissions, and (3) the obvious characteristics of the source
(which can be related to either sight or smell).