You're right. The same goes for gasoline, natural gas, ethanol, etc., because of the way the environmentalists count Carbon dioxide but not Oxygen weight.
For example, let's burn methane in the presence of oxygen. 16 grams of methane magically become 44 grams of carbon dioxide emissions.
CH4 + 2O2 --> CO2 + 2H2O + heat
(16) + (64) --> (44) + (36) grams/mole