Question

I understand that the byproducts of burning methane to be carbon dioxide and water, and in low oxygen situations, carbon monoxide.

CH_4+2O2⟶CO_2+2H_2O
2CH_4+O2⟶2CO+4H_2
Where does nitrogen come into this? How does burning methane produce nitrogen oxides?

Answer 1

Nitrogen oxides are produced during the burning of methane because the high temperatures of combustion allow nitrogen from the air to react with oxygen to form nitrogen oxides as unwanted by-products.

Step-by-step explanation:

Burning methane (CH4) in the presence of oxygen (O2) primarily produces carbon dioxide (CO2) and water (H2O). However, since combustion is a high-temperature reaction, nitrogen from the air can react with oxygen to form nitrogen oxides (NOx).

The air is composed of roughly 78% nitrogen (N2), which usually does not react at lower temperatures. But in a combustion environment, such as a gas stove or Bunsen burner.

The heat provides enough energy to overcome the strong triple bond in diatomic nitrogen. This process leads to the formation of various nitrogen oxides.

Like nitric oxide (NO) and nitrogen dioxide (NO2), as unwanted (pollutant) by-products due to the high temperatures involved in the combustion process.