What are flue gases primarily composed of in fossil fuel combustion?

Flue gases from the combustion of fossil fuels are primarily composed of carbon dioxide and water vapor. During combustion, carbon-based fuels, such as coal, oil, or natural gas, react with oxygen in the air. This chemical reaction primarily produces carbon dioxide as a result of the oxidation of carbon, and water vapor as a product of the combustion of hydrogen found in these fuels.

In a typical combustion process, the carbon content converts into carbon dioxide, contributing to greenhouse gas emissions, while hydrogen combines with oxygen to form water vapor. The presence and proportions of these gases in flue gas can vary based on the type of fossil fuel being burned, the combustion temperature, and the efficiency of the combustion process, but carbon dioxide and water vapor remain the predominant products.

Understanding the composition of flue gases is essential for addressing environmental concerns, such as climate change and air quality, as carbon dioxide is a key greenhouse gas.