Emissions Components

Emission

Source

Effect

Green House Gas Potential Relative to CO2

CO2 (Carbon dioxide) Complete combustion of carbon in fuel Global Warming

1

CO (Carbon Monoxide) Incomplete combustion of carbon in fuel Smog
SO2 (Sulphur Dioxide) Combustion of sulphur in fuel (Sulphur is NOT a component of natural gas) Smog, Acid Rain
NOx (Nitrous Oxide) By-product of most combustion processes Acid Rain
N2O (Nitrous Oxide) By-product of some combustion processes Global Warming

310

VOCs (Volatile Organic Compounds) Leakage and evaporation of liquid fuels Smog
CH4 (Methane) Natural Gas Leaks Global Warming

21

H2O (Water Vapor) Hydrogen in fuel mixing with oxygen in the combustion process Localized Fog
Particulates (Dust, Soot, Fumes) Unburned carbon from fuel, including ash and dirt Smog, Respiratory Hazard
Trace Elements Impurities in fuel Unknown and Potential Carcinogens
Halogenated and Chlorinated Compounds Compounds in fuel or combustion air containing halogens (Chlorine, fluorine, bromine and iodine) Potential carcinogens, Global Warming

For a complete discussion about NOx, NOx Control and low-NOx Equipment, see Boiler Emissions Workshop