CO2 intensity: Per kilogram of fuel combusted, the following fuels release the following amounts of energy: butane (C4H10), 50 MJ; wood (CH20), 10 MJ; gasoline (C3H28),50 MJ; coal (pure carbon), 30 MJ. a. Calculate the energy released per kilogram of CO2 emitted for these fuels. b. Your text calculates the energy released per kilogram of emitted CO2 for methane (CH4) to be 18.2 MJ/kg-CO2. Order all five (5) fuels from cleanest to dirtiest. What is the emission advantage of natural gas when compared to coal