Environmental Engineering Reference
In-Depth Information
something about costs and ef
ciency of the capture pro-
cess. How much energy does it take and what fraction of
the CO
is captured in the real world? CCS does not have
to be perfect to make a huge contribution to cutting
greenhouse gas emissions. At
ciency, coal
would become a small contributor to climate change and
the world would have much more time to develop the
technologies that will be needed in the long term to get
emissions fully under control.
Tests of the deep saline aquifers with carbon dioxide
loading don
% capture ef
t need a new power plant to supply the gas.
We can start with CO
from any source (a lot is needed)
and begin to learn what happens as the system becomes
more acidic with CO
'
loading. No one seems yet to be
doing that.
In October of
the US Environmental Protection
Agency (EPA) proposed regulations limiting the CO
emissions of both coal- and gas-fueled electric power
plants. There will be a comment period and then
final
regulations will be issued. At the time of writing I do not
know what the
final regulations will be, but do not think
much of the proposal in any event. They are for new
plants, and modern gas plants already meet them. Coal
plants do not and the EPA says that CCS is a viable
technology, citing experience with injection into oil
fields
for enhanced recovery of oil (EOR). Their example is
irrelevant because the amount of CO
used in EOR is
tiny compared with what is produced in electricity gener-
ation, and so the problem is fundamentally different.
There is potential large-capacity underground storage
capability in deep saline aquifers, but no one knows if
these can contain CO
for centuries without leaking. If
