Air pollution emissions from gas turbines are almost exclusively from combustion, but there is a potential for emissions from the storage of the fuel for a gas turbine. Combustion emissions from
a gas turbine include nitrogen oxides (NO x), sulfur dioxides (SO x), carbon monoxide (CO), un-burned hydrocarbons, and particualte matter. The storage of fuels can be potential sources of emissions because volatile hydrocarbons or volatile organic compounds (VOCs) can escape from storage and enter the atmosphere. Overall, No x and CO are the most significant emissions from gas turbines.
Natural gas is the fuel often used for a stationary gas turbine, and it is usually delivered to a plant via a pipeline and generally is not stored at a plant in large quantities. Methane (CH 4) is the main gas component in natural gas, as well as various amounts of ethane (C 2H 6), and other hydrocarbons. Methane is a greenhouse gas but it is not considered to be a VOC; ethane is not a VOC.
A variety of petroleum distillates from heavier fuels to light gases can be used to run a gas turbine. These fuels include diesel, kerosene, jet fuel, gasoline, propane, butane, methane and others. The storage of gasoline is a source of VOC emissions. Diesel fuel is sometimes used as a backup or emergency fuel for a gas turbine, but its vapor pressure at ambient conditions is low enough to prevent problems with VOC emissions.