"Different fuels emit different amounts of carbon dioxide (CO2) in relation to the energy they produce when burned. To analyze emissions across fuels, compare the amount of CO2 emitted per unit of energy output or heat content.
Pounds of CO2 emitted per million British thermal units (Btu) of energy for various fuels:
Coal (anthracite)
228.6
Coal (bituminous)
205.7
Coal (lignite)
215.4
Coal (subbituminous)
214.3
Diesel fuel and heating oil
161.3
Gasoline (without ethanol)
157.2
Propane
139.0
Natural gas
117.0
The amount of CO2 produced when a fuel is burned is a function of the carbon content of the fuel. The heat content or the amount of energy produced when a fuel is burned is mainly determined by the carbon (C) and hydrogen (H) content of the fuel. Heat is produced when C and H combine with oxygen (O) during combustion. Natural gas is primarily methane (CH4), which has a higher energy content relative to other fuels, and thus, it has a relatively lower CO2-to-energy content. Water and various elements, such as sulfur and non-combustible elements in some fuels reduce their heating values and increase their CO2-to-heat contents."
Other production and processing emissions prior to burning are not included.
The burning of fossil fuels for conversion to useful energy like heating a house, heating water, or cooking will is much less than 100%. Much of the heat is lost to the venting required to remove the toxic gases in burning.
Coal fired power plants efficencies are in the 30% to 45% range
Combined cycle nat gas fired power plants are in range of 50% to 65% range
Condensing natural gas water heaters are 90+% efficient. Space heating with gas can be around 80% efficient.
Definitely well under 100%, but light years ahead of things like vehicles, which are under 50% efficient. (Diesels can get close to that, gasoline tops out in the mid 30’s percent efficient.)
Not my problem that Canada wants to sell its old growth wood slash and unusable parts (branches, leaves, bark and sawdust) for making pellets for burning. This is still renewable subset of biofuels.
From the Laganiere paper linked upthread:
" For coal, oil, and natural gas combustion, we used the following emission factors: 90.6, 71.1, and 50.3 kg CO2eq GJ−1, respectively. For wood biomass, we used the default IPCC emission factor of 112.0 kg CO2eq GJ−1."
In the longer term wood biomass is better than fossil fuels for reducing CO2 in the atmosphere.
From the Laganiere paper linked upthread:
Overall, our results are coherent with the perspective of Haberl et al . (2012) on C emission reduction by bioenergy.
Short- to medium-term atmospheric benefits (<50 years C parity time) must involve the use of ‘additional biomass’, defined as biomass from additional vegetation growth or biomass that would decay rapidly if not used for bioenergy. Such parity times are possible in some cases under salvaged tree scenarios, but more likely under specific conditions involving important gains in forest productivity (silviculture) under either green tree or salvage tree scenarios.