Hi, Could you please confirm these estimations for me: Knowing that the Energy of Combustion of CH4 is 50.1 KJ/Kg, and that the specific heat for the CO2 at 273.15 K is approximately 0.81 KJ/Kg*K; please, could you confirm that in order to increase the temperature of 1 liter of gas of CO2 at 273.15K and 100 KPa (density = 1.98 Kg/m^3, so 0.00198 Kg), from 273.15 K to 573.15 K, it is only needed to combust 0,0000096 Kg of CH4. It is supposed an ideal / isolated system, without heat looses. Q = m * c * AT Q = 0.00198 * 0.81 * 300 = 0.481 KJ Then: 0.481 / 50.1 * 10^3 = 9.6 * 10^-6 Kg, approximately just 0.015 liter. It seems to be a very little portion of CH4 to me. Thanks for your help. PS – I apologize for my English, I am learning it.