Statement based on a eia/epa government published table. The source for the statistics are not provided. It is hard for me to understand how the oxidation of coal based carbon is different than oxidation of natural gas carbon. But then biochemistry was something I didn't study.
I think it has to do with impurities, etc.
>> Natural gas generates half the CO2 per kilowatt-hour
> It is hard for me to understand how the oxidation of coal based carbon is different than oxidation of natural gas carbon
1) Natural gas is 25% hydrogen by weight (Coal is around 3 percent hydrogen). Much of the energy released by burning NG is from the oxidation of hydrogen.
2) Modern natural gas electric plants use the highly efficient “Combined cycle” design, which converts about 60% of the chemical energy in the NG into electricity. Coal plants do not use combined cycle, and typically get about 40% conversion.
Add those factors together, and it’s not hard to see that per mole of carbon, methane can yield about twice as many watt/hours as coal.