What percentage of excess oxygen is generally needed for the combustion of gaseous fuel?

The combustion of gaseous fuels typically requires a certain percentage of excess oxygen to ensure complete combustion. The correct answer indicates a range of 3-10% excess oxygen, which is generally optimal for achieving efficient combustion.

This range helps to ensure that all fuel is burned completely, preventing the formation of harmful carbon monoxide and unburned hydrocarbons. Additionally, having the appropriate excess oxygen allows for better temperature control within the combustion process, which is crucial for optimizing energy output and minimizing pollutants. If the excess oxygen level falls below this range, incomplete combustion may occur, leading to inefficiencies and increased emissions.

Conversely, higher percentages of excess oxygen may also be detrimental as they can lead to unnecessary heat losses and may cool the combustion process too much, affecting efficiency. This understanding of excess oxygen percentages is vital for anyone involved in power engineering and combustion processes.