Encyclopedia of Environmental Science and Engineering, Volume I and II

VAPOR AND GASEOUS POLLUTANT FUNDAMENTALS 1231

gaseous properties including the heat liberated during

combustion are presented.

An excess of air is typically used over the theoretical

amount of oxygen actually required for combustion; see

Table 10.

In both instances safety considerations are important

for preventing explosive mixtures. The detonation limits

for various pure gases with air are presented in Table 12

below.

Talmage (1971) describes a flammability envelope dia-

gram which must be considered for handling flammable

vapors, Figure 18(a),(b). By appropriately adding inerts or

other fuel, it is possible to operate outside of such an enve-

lope. Another review focuses on the addition of nitrogen to

combustion mixtures (Subramaniam, 1990).

REACTION RATE PARAMETERS

Table 13 is a compilation of bimolecular reaction rate

constants involving typical pollutants.

The decomposition of ozone takes place with a rate con-

stant (Laider, 1965)

k  4.6 × 10^15 e−2400/RT cc mole−1 sec−1.

POLLUTANT CONTROL METHODS

Gases containing compounds of sulfur such as SO 2 , SI 3 , H 2 S

and mercaptans have received the widest attention for the

purpose of control of all noxious gases. For this reason the

NOTE: GUIDE LINES ARE DRAWN FOR

TYPICAL FUEL OIL WITH C/H 2 =7.5

FUEL HIGH HEAT VALUE-1000 BTU/LB

ATM

OS

PHE

RIC

AIR

C/H

2

B

AA

C

H 2 -15 PER CENT BY WEIGHT AS FIRED

14

17 18 19 20 21 22

13

12

11

10

9

6

5

4

7

8

9

0 10

7.0

8.0

9.0

10.0

11.0

12.0

13.0

14.0

15.0

16.0

17.0

20 30 40 50 60 70 80 90 100

30

40

50

60

70

80

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

EXCESS AIR-PER CENT

CO

IN DRY PRODUCTS–PER CENT BY VOLUME 2

H

O FROM COMBUSTION OF H 2

2

ATMOSPHERIC AIR

POUNDS PER MILLION BTU AS FIRED

FIGURE 17 Chart for fuel oil (Fryling, 1966).

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