Encyclopedia of Environmental Science and Engineering, Volume I and II

NITROGEN OXIDES REDUCTION 757

In addition to the conversion properties of the graph,

some of the pertinent local, state and federal regulations

have been included on the graph for quick comparison to the

NO x levels.

CONTROL OF NO x

Introduction

As noted earlier, there are numerous ways to control NO x

emissions from combustion systems. Control methods can

be broken down into two categories: (1) technologies that

reduce emissions during the combustion process; (2) tech-

nologies that reduce emissions after combustion has taken

place. Technologies used during the combustion process

typically utilize different stoichiometric balances or burner

configurations to decrease NO x formation. Post combustion

technologies, such as SCR, utilize reactants, with or without

catalysts, to break down the NO x before it is exhausted to the

atmosphere. Table 15 22,23 shows some of the control methods

used in industry along with the NO x reductions that can be

expected. The following is a detailed description of each of

the common processes used in industry today.

TABLE 10^

Properties of gaseous fuels (% by weight) 18,19

Fuel CH 4 C 2 H 6 C 2 H 8

Other

hydro-carbons CO H 2 H 2 SN 2 CO 2 “K” factor

HHV

(MJ/m^3 )

Natural Gas

No. 1 77.7 5.6 2.4 1.8 — — 7.0 — — 972.34 40.4

No. 2^1 88.8 6.4 2.7 2.0 — — 0.0004 — 0.0 922.09 41.9

No. 3 59.2 12.9 — — — — — 0.7 26.2 1293.4 30.7

No. 4 99.2 — — — — — — 0.6 0.2 892.52 36.3

US/Texas 80.9 6.8 2.7 1.6 — — — 7.9 0.1 952.93 41.1

North Sea 94.4 3.1 0.5 0.4 — — — 1.1 0.5 958.76 40.3

Denmark 91.2 4.8 1.7 1.1 — — — 0.5 0.7 956.19 42.6

Holland 81.3 2.9 0.4 0.2 — — — 14.3 0.9 973.06 35.2

Russia 98.0 0.6 0.2 0.1 — — — 1.0 0.1 969.24 39.2

Germany 74.7 0.1 — — — — — 7.2 18.0 1680.8 41.2

Refinery Gas

No. 1 41.6 20.9 19.7 15.6 — — 2.2 — — — 68.6

No. 2 4.3 82.7 13.0 — — — — — — — 67.1

No. 3 15.9 5.0 — 2.4 14.3 50.9 — 8.4 2.2 — 18.7

Coke oven

gas

— — — 35.3 6.3 53.0 — 3.4 1.8 — 21.5

Blast furnace

gas

————26.2 3.2 — 57.6 13 — 3.4

Methane 100.0 — — — — — — — — — 38.9

Hydrogen — — — — 100.0 — — — — 12.4

1 “Sweetened”; H 2 S removed.

TABLE 11^

Properties of Liquid Fuels 18,20

Percent by weight

Fuel C H N O S Ash

Specific

gravity “K” factor HHV (MJ/kg)

Kerosene (No. 1) Fuel Oil 86.5 13.2 0.1 0.1 0.1 Trace 0.825 926.32 46.4

No. 2 86.4 12.7 0.1 0.1 0.4–0.7 Trace 0.865 916.47 45.5

No. 4 85.6 11.7 0.3 0.4  2 0.05 0.953 895.69 43.4

No. 6 85.7 10.5 0.5 0.4 2.8 0.08 0.986 896.05 42.5

No. 6 (Arthur Kill) 86.9 12.6 0.2 0.0 0.3 0.02 0.9059 903.35 44.9

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