A yellow flame at the waste-gas burner indicates what?

A yellow flame at the waste-gas burner is indicative of low combustion efficiency, typically associated with the production of soot and carbon particles. This occurs because incomplete combustion leads to carbon compounds burning in a less efficient manner, resulting in yellow coloration due to the presence of incandescent carbon particles.

In context, a yellow flame often reflects a cooler combustion temperature, which does not reach the high temperatures necessary for complete combustion of the fuel. Consequently, this can lead to higher carbon monoxide and unburned hydrocarbons in the output, rather than increased carbon dioxide, which is a byproduct of more complete combustion. A blue flame, in contrast, indicates that combustion is occurring more efficiently at a higher temperature, typically producing more carbon dioxide and less soot.

Hence, while the presence of a yellow flame can suggest potential issues such as excessive carbon emissions, it is not directly associated with increased levels of carbon dioxide resulting from complete combustion.