- #1
Archosaur
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http://europe.theoildrum.com/node/6638" has a chart that claims that the burning of methane yields 360 g of CO2 per kWh of energy released. I decided to check that, but I'm not getting the same answer they suggest. Here's what I did:
CH4 + 2O2 = 2H2O + CO2
-74.87 + 0= 2*-285.83 + -393.509
= -571.66 + -393.509 +74.87= -890.229 kJ/mol
(all standard enthalpies of formation came from wikipedia)
CO2 is 44.011 g/mol
890.229 kJ is 0.24728583333 kWh (significant figures be damned)
44.011/0.24728583333 ≈ 178 g/kWh, as opposed to their 360 g/kWh
I can't help but notice that my answer is suspiciously close to a factor of 2 off... but my eq. is balanced...
Can someone tell me what I've done wrong?
Thanks
CH4 + 2O2 = 2H2O + CO2
-74.87 + 0= 2*-285.83 + -393.509
= -571.66 + -393.509 +74.87= -890.229 kJ/mol
(all standard enthalpies of formation came from wikipedia)
CO2 is 44.011 g/mol
890.229 kJ is 0.24728583333 kWh (significant figures be damned)
44.011/0.24728583333 ≈ 178 g/kWh, as opposed to their 360 g/kWh
I can't help but notice that my answer is suspiciously close to a factor of 2 off... but my eq. is balanced...
Can someone tell me what I've done wrong?
Thanks
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