> Surely, there are
> other sources of hydrocarbons which can be used to make liquid fuels,
> but the Energy Return On Energy Invested (EROEI) for all these sources
> is less than that for the easy to get at oil we so carelessly burned.
EROEI seems like a nice concept, but unless the Energy In is truely
equivalent to the Energy out and more is used than produced, EROEI is
surprisingly insignificant.
> Tar Sands are a prime example, as natural gas is used to separate the
> dense tar from the mixture.
Why are oil sands commercial? The Energy In is mostly low temperature
(and very low value) process heat, the energy Energy out is high value
transportation fuels.
What's the EROEI of a Gas to Liquids plant? Is input greater than
output here?
You can have 100 kWh of oil sands removed from the earth with 50 kWh
of natural gas. Some people will claim this is an EROEI of 2:1. Yet,
with 100 kWh of natural gas input to a GTL plant and 50 kWh of
transportation fuel output, we might get half the transportation fuel
output for twice the natural gas input, but some people will claim the
EROEI is 5:1 or higher for the GTL route because little energy got
used to extract the natural gas.
> They can be used to produce enough energy to keep things
> going, but not enough to allow everybody on the planet to live like
> the (formally) rich Americans who were able to waste oil and other
> energy sources with abandon.
Well, the IPCC scenarios do as far as I know assume that the average
world citizen in 2100 will be twice as rich as the average American
was in the year 2000.
--
You received this message because you are subscribed to the Google Groups
Global Change ("globalchange") newsgroup. Global Change is a public, moderated
venue for discussion of science, technology, economics and policy dimensions of
global environmental change.
Posts will be admitted to the list if and only if any moderator finds the
submission to be constructive and/or interesting, on topic, and not
gratuitously rude.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to
[email protected]
For more options, visit this group at
http://groups.google.com/group/globalchange
