Combustion Gas Analysis Quiz

Oxygen gas (O2) is a key indicator of combustion efficiency in flue gas analysis. Its percentage reveals how effectively fuel is burnt and how much air is present in the combustion process.

Flue gas analysis aims to assess the completeness and efficiency of fuel combustion. It helps determine how well the fuel is burning and whether there are any inefficiencies or pollutants.

Percent volume (%) is the standard unit for measuring components within flue gas, indicating the proportion of each gas present.

Carbon monoxide (CO) is a byproduct of incomplete combustion, indicating that the fuel is not burning completely. Its presence means that energy is being wasted and potentially harmful emissions are being released.

To convert percent by volume (%) to parts per million (ppm), multiply the percentage by 10,000. This is useful for comparing and analyzing very small concentrations of gases.

To convert parts per million (ppm) to percent by volume (%), divide the ppm value by 10,000. This conversion helps you understand the relative abundance of gases.

0.05% NO2 is equivalent to 500 ppm. This conversion helps express a very small percentage into a more manageable number for analysis and comparison.

As excess air increases, the amount of carbon monoxide (CO) in flue gas decreases. This is because with more air, there is more oxygen available for complete combustion, reducing the formation of CO.

For a coal-fired plant with 30% excess air, the CO percentage in the flue gas would be approximately 12.2%. This reflects the relationship between excess air and combustion efficiency.

For a coal-fired plant with 40% excess air, the O2 percentage in the flue gas would be approximately 5.2%. This demonstrates the correlation between excess air and oxygen presence.

The percentage of excess air used in a coal-fired boiler can be calculated based on the flue gas components. In this case, with the provided composition, the excess air is 80%.