October 19, 2007
Reducing Greenhouse Gas Emissions: The Role of Geologic Storage
of CO2
Lynn Orr (Stanford) [Lecture
will be held in Ramo]
There is a consensus that we humans will need to reduce emissions
of greenhouse gases substantially in this century if we are to
avoid unacceptable modifications to climate and the biogeochemistry
of the ocean. Hence the important question is: how
are we to do that? The challenge, to change the world’s
energy systems, is a huge one, and there is no single, simple
solution to it. We need to improve energy efficiency dramatically,
move increasingly to use of energy resources that have low or
zero net emissions of greenhouse gases (solar energy, some biofuels,
wind, nuclear power, geothermal power, …), or to the extent
that carbon stays in the fuel mix, capture and store an increasing
fraction of the CO2 that results. This talk explores the
potential for use of large-scale storage of CO2 in porous rocks
in the Earth’s crust. It considers the following
questions:
- Can we capture the CO2 efficiently?
- Do we have enough variety of geologic settings for storage?
- Is there sufficient volume available in the subsurface to store
enough CO2 to have an impact?
- Are there appropriate physical mechanisms that will immobilize
the CO2 in the subsurface to design safe storage projects that
won’t leak?
- Can we predict where the CO2 will go and can we monitor adequately
where the CO2 went?
- Do we have enough experience with actual operations to undertake
storage at scale?
he answers to these questions depend on the geologic setting,
but there is enough knowledge and experience to support design
and operation of projects at significant scale now in some of them,
and research is underway on many challenging research questions
involving chemical separations and multiphase flow in the subsurface
to increase the base of knowledge for geologic storage of CO2.
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