Page 32 - Handbook of Energy Engineering Calculations

By using the procedure in step 5, the percent CO , wet basis = 53.6/362.35
2
= 14.8 percent. The percent CO , dry basis = 53.8/(362.35 − 17.6) = 15.6
2
percent.

Related Calculations. Use the method given here when making combustion
calculations for any type of coal—bituminous, semibituminous, lignite,
anthracite, cannel, or cooking—from any coal field in the world used in any

type of furnace—boiler, heater, process, or waste-heat. When the air used for
combustion contains moisture, as is usually true, this moisture is added to the
combustion-formed moisture appearing in the products of combustion. Thus,
for 80°F (26.7°C) air of 60 percent relative humidity, the moisture content is

0.013 lb/lb (0.006 kg/kg) of dry air. This amount appears in the products of
combustion for each pound of air used and is a commonly assumed standard
in combustion calculations.
Fossil-fuel-fired power plants release sulfur emissions to the atmosphere.

In turn, this produces sulfates, which are the key ingredient in acid rain. The
federal Clean Air Act regulates sulfur dioxide emissions from power plants.
Electric utilities which burn high-sulfur coal are thought to produce some 35
percent of atmospheric emissions of sulfur dioxide in the United States.

Sulfur dioxide emissions by power plants have declined some 30 percent
since passage of the Clean Air Act in 1970, and a notable decline in acid rain
has been noted at a number of test sites. In 1990 the Acid Rain Control
Program was created by amendments to the Clean Air Act. This program

further reduces the allowable sulfur dioxide emissions from power plants,
steel mills, and other industrial facilities.
The same act requires reduction in nitrogen oxide emissions from power
plants and industrial facilities, so designers must keep this requirement in

mind when designing new and replacement facilities of all types which use
fossil fuels.
At the time of this writing, there are a number of states and countries
considering phasing out coal-burning power plants at the end of their useful

commercial lives if they do not install means to capture carbon dioxide and
other greenhouse gases. These entities are also urging a shift to natural-gas
fuel. Further, combined-cycle natural-gas-fueled power plants are being
urged as replacements of coal-fired power plants.