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mheslep
#5
Sep27-09, 08:42 PM
PF Gold
P: 3,098
Quote Quote by joelupchurch View Post
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It analyzes the total GHG life cycle emissions for power from natural gas and coal. The numbers they come with are that NG isn't that much better than coal and LNG is actually much worse than coal. This set off my BS detector, but when I checked it, the paper is actually pretty good. They account for things like the release of NG during the production process. Since NG is 96% methane and methane is 20 times worse than CO2 as a GHG, that is a big difference right there.

I'd always assumed that natural gas emitted about half the CO2 as coal, which is true, but incomplete.
Eh? The paper shows NG equivalent CO2 emissions (1100 lbs/MWh) still has nearly half that of coal (2100 lbs/MWh) considering life cycles, and is vastly better than coal in SOx and NOx emissions. Even liquefied gas is not 'much worse' than coal per this paper and even if it was, so what? LNG is less than 2% of the mix and falling (~27TCF gas total US, 0.5 TCF liquefied ). Also, I see methane concentration in the atmosphere has been flat in the atmosphere for the last ~10 years.
http://www.epa.gov/methane/images/methane.gif