What is Flue gas?

Flue gas is the gas exiting to the atmosphere via a flue, which is a pipe or channel for conveying exhaust gases from a fireplace, oven, furnace, boiler or steam generator. Quite often, the flue gas refers to the combustion exhaust gas produced at power plants. Its composition depends on what is being burned, but it will usually consist of mostly nitrogen derived from the combustion of air, carbon dioxide , and water vapor as well as excess oxygen. It further contains a small percentage of a number of pollutants, such as particulate matter , carbon monoxide, nitrogen oxides, and sulfur oxides.