Conclusion
The first question we ask is if sequestration of carbon dioxide
will work at all? We have carefully investigated each method of
sequestration, and nothing jumps out as a foolproof way to sequester
CO2. Each method seems to have some sort of flaw. There
is no perfect way to deal with the carbon dioxide problem. Still,
it is unreasonable to expect that we, as a global community, will
be able to become independent of fossil fuels any time in the near
future, and something has to be done with all that carbon dioxide.
There certainly are methods of sequestration that are viable storage
sites for the disposal of carbon dioxide.
There is no one best method for sequestering carbon dioxide; each
method has its advantages and disadvantages. We foresee the future
of carbon dioxide sequestration as a combination of all the different
methods, with some more prominent than others.
Mineral mines can store more carbon dioxide than can be burned
by fossil fuel. They are safe, cost efficient, and the carbon is
stored permanently as solids. The biggest downside to them is that
extensive mining, involving unknown environmental impacts, would
be necessary.
Oceans have the largest storage capacity, but we believe too little
is known about the future effects on the environment for oceans
storage to be useful as a sequestration method in the near future.
Although some scientists argue that the pH change and CO2 concentration
change would not be significant, public perceives “dumping”
CO2 into the ocean to be a major threat. Public dissent has even
hindered research and development of ocean sequestration technology.
Aquifers should be a viable storage option in the future because
of it’s enormous capacity, but as of now, the technology is
too immature. Extensive research must be done on each aquifer concerning
its capacity, integrity, and possible carbon dioxide behavior before
it can be considered a viable site. There is no existing data to
indicate what these characteristics might be. Aquifers are also
not value added sites. However, the Sleipner project has proven
that aquifer storage is indeed possible. Aquifers deserve to further
looking into.
Depleted Oil and Gas Reservoirs have the integrity, but they don’t
have the size. They simply don’t have the storage capacity
to be the main sequestering method. The technology is also expensive
due to capturing, processing, and transportation costs. However,
used in conjunction with another method, we feel that depleted oil
and gas reservoirs are a good option.
Enhanced Oil Recovery will be a good method as long as it is profitable
for oil companies. Oil companies, whose main focus is the recovery
of oil, not the sequestration of CO2, fund most EOR projects. There
is also not a lot of storage capacity involved with EOR. The value-added
aspect will allow it to continue as a good method for the time being.
Coal Beds are a very good place to store CO2. They are permanent,
they are inexpensive, and they result in the recovery of natural
gas. There is also a large storage capacity, although not as large
as some others. Coal beds are only a viable option for 100-200 years,
so it should be used in conjunction with another technology.
Other than EOR, which has been a successful method of oil recovery
and carbon dioxide sequestration for over thirty years, no technology
is ready to be used on a large scale. It would be unfair to completely
rule any method out before they have all been fully tested. Each
and every one of these methods is better than allowing carbon dioxide
emissions to continue at its current rate unchecked.
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