New York Low Pressure Boiler COF Practice

When assessing combustion efficiency, which gas is typically analyzed?

1. Carbon monoxide (CO)

2. Oxygen (O2)

3. Carbon dioxide (CO2)

4. Nitrogen (N2)

The correct answer is: Carbon dioxide (CO2)

When evaluating combustion efficiency, carbon dioxide (CO2) is the primary gas analyzed because it is a key indicator of the complete combustion of fuel. When a fuel burns completely in the presence of sufficient oxygen, it converts into carbon dioxide and water vapor. The presence of a higher concentration of CO2 in the flue gases signifies that the combustion process is efficient, as it indicates that most of the carbon in the fuel has been converted to this byproduct. Analyzing CO2 levels allows operators to assess how effectively fuel is being utilized. In a properly functioning combustion system, the ratio of CO2 to other gases can provide critical insights about fuel efficiency and the amount of excess air being introduced into the process. While carbon monoxide (CO) is also a gas of concern during combustion analysis, it is typically a sign of incomplete combustion and, therefore, not a direct measure of efficiency. Oxygen (O2) levels are related to combustion quality, but high levels of excess oxygen can indicate inefficient combustion along with the presence of unburnt fuel. Nitrogen (N2) comes primarily as an inert gas in combustion and does not provide valuable insight into combustion efficiency. Hence, CO2 stands out as the most relevant gas for this purpose.