CO2 is part of the desired outcome....
Of
“During complete combustion carbon and hydrogen combine with oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). During incomplete combustion part of the carbon is not completely oxidized producing soot or carbon monoxide (CO).”
We baby boomers learned this 7th grade science.....
There is a lot of other stuff in coal besides carbon. Did they teach that to you in Podunk?