Final answer:
A yellow flame from a digester gas burner usually indicates a high concentration of hydrogen sulfide, leading to poor gas quality and the release of combustion pollutants.
Step-by-step explanation:
A yellow flame coming from the digester gas burner indicates poor gas quality due to a high concentration of hydrogen sulfide.
Combustion pollutants, such as hydrogen sulfide, are emitted or formed through chemical reactions during the combustion of fuels like natural gas, gasoline, diesel, or coal
If the gas used in a burner contains a high concentration of hydrogen sulfide, it can result in a yellow flame, which is generally a sign that the gas combustion is incomplete.
This incomplete combustion leads to the formation of combustion pollutants, including carbon monoxide, nitrous oxides, and sulfur dioxide, which can be hazardous to health and the environment.