Carbon Capture and Sequestration (CCS) is the fossil fuel industry’s much-touted cure-all for our global warming woes. This theoretical solution to global warming is to pump all our industrial releases of CO2 underground, cross our fingers, and hope really, really hard that it will stay there – literally sweeping the problem under the proverbial rug.
It’s a nice dream, but how realistic is it? A new report has examined the feasibility of CCS, and found it “overwhelming in both physical needs and costs” and the entire strategy for geological sequestration “profoundly non-feasible.” Titled Sequestering Carbon Dioxide in a Closed Underground Volume, the report was published in the peer-reviewed Journal of Petroleum Science and Engineering and written by M.J. Economides of the Department of Chemical Engineering, University of Houston and C.A. Ehlig-Economides of the Department of Petroleum Engineering, Texas A&M University.
(EDITOR’S NOTE: It has been pointed out to us that many of these claims made by Dr. Economides may be overinflated or just plain spurious- a retort posted by NRDC here. Because we don’t believe in just throwing blog posts down the memory hole, we want to give this big caveat, and watch for a further discussion on CCS feasibility)
An article in the Canada Free Press examined some of the specifics of the report. Quoted in the article is coauthor Michael Economides who said that, “over-inflated claims for CCS have become the last refuge of the energy scoundrel” – and he says those scoundrels are the coal companies.
The report, which can be purchased and downloaded here, examines a number of the different factors of CCS including erroneous assumptions about potential volume of sequestration sites. Michael Economides, co-author of the report, is a professor of Petroleum Engineering and an expert on injection, having worked in 70 countries doing CO2 injection. One of the biggest problems with the assumptions the industry is making, he says, is comparing enhanced oil recovery (EOR) to what’s called deep-saline aquifer sequestration. That’s a lot of technical jargon, and I’ll try to break it down here in the next few sentences.
When an oil field is first drilled there is a lot of pressure in it, but over time as the oil is removed from the well this pressure is reduced (kind of like deflating a balloon). EOR is a process by which CO2 is injected into the oil field in order to re-pressurize the well so that the oil gets pumped out faster (like re-inflating the balloon). This process has been done for decades, but ensuring the sequestration of the CO2 has not been the objective – maximizing production of oil has. I had the opportunity to talk to Michael Economides on the phone. He said there is a very limited amount of recoverable oil left in the US that could employ EOR and sequester CO2 underground. At best, over the course of 30 years, these EOR sites could sequester less than one year’s worth of the CO2 emissions in the United States.
So the industry’s proposed solution to this limitation is to sequester the rest of the CO2 into “deep-saline aquifers.” These are deep aquifers of brackish, brine water far below the earth’s surface – far deeper and harder to reach than oil fields. These aquifers are also not being emptied so you’re trying to stuff the CO2 into a space that’s already mostly full of water – unlike the oil fields where you’re creating space for the CO2 by pumping the oil out. As Professor Economides explained it, imagine pumping up a tire with a bicycle pump and compare that with putting the pump nozzle against a wall and trying to pump air into the wall. The space required here is simply massive. He said to sequester the CO2 emissions from just one small, 500 MW coal plant over the course of 30 years would require an aquifer the size of Rhode Island. Economides pointed out that one 500 MW coal plant is only about 1/600 of the total coal plants in the United States. So for coal plants alone you’d need about 600 aquifers the size of Rhode Island in order to make CCS a viable solution to man made global warming. We just don’t have that kind of potential storage space.
The list of problems with CCS goes on and on, and includes safety issues and the feasibility of ensuring sequestration over the course of thousands of years (similar to the nuclear waste problem) – you can read more about some of them in the report. Even if they could get CCS to work it still does nothing to address the mining of coal, the other emissions, or the disposal of the waste products. Professor Economides said to me “CO2 sequestration is just not going to happen,” so since these new CCS plants cost about $1 billion, or 1/3 more than a conventional plant, shouldn’t we be putting the money in to cheaper alternatives – such as energy efficiency and renewable energy? The CO2 is already sequestered in the ground in the form of coal. Let’s just leave it there and save ourselves a world of hurt.
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[...] aspects of this project, as I’ve already talked about in a previous post, carbon capture and sequestration is a pipe dream anyway. It’s too expensive, the technology [...]
The Economides couple got this one wrong. Their assumptions have been rebutted by a wide array of scientific and research bodies as well as stakeholders from across the board. For more details read my blog here: http://switchboard.nrdc.org/blogs/gperidas/economides_x2_try_their_hand_a.html
Great link! Thanks for weighing in on this. I think everyone should take advantage of this scientific debate and get educated about the issues and economics of CCS and make up their own minds.
We’ll have a more detailed analysis (and possibly debate) coming soon of this, but this seems very, very odd: A climate change denier saying this technology won’t work vs. oil company scientists saying it will (since up until very recently it was only studies from API, etc that were disputing this).
Although we are now beginning to see academic debate on this, we should take all of these ideas with a giant pinch of salt- preferably salt harvested from a deep brine aquifer used to sequester carbon?
What we do know is regardless of this, efficiency and renewables are proven technologies and have a proven track record of carbon reductions. CCS is new and untested at the scale proposed by the claims of the Tenaska Trailblazer plant, etc.
I asked a geologist friend of mine in Houston about his take on this and this was his response:
The science is basically right, you cannot pressure up on these formations past the strength of the caprock without rupturing the reservoir. With the depth that they are planning on placing these reservoirs (2500′) there isn’t really that much overburden in place so the strength of the caprock isn’t that great. This applies to a reservoir with impermeable boundaries, which would be found over a lateral extent of hundreds of square feet to a few square miles, and would not have alot of inherent storage capacity anyway. . The case they talk about with the reservoir that covers a great distance (hundreds to thousands of square miles) is pretty much correct too, you can pump alot of gas into them at low pressures, but the unfortunate part of these formations is that it would be extremely costly to verify the integrity of the reservoir over such a great extent, though you could probably do it if you spent a couple hundred million on extensive 3d seismic coverage.
You know how I feel about this technology, the idea that these formations will hold this gas indefinitely is terribly flawed and is along the same “Out of sight, out of mind” mentality that created the thousands of Superfund sites around this country that we are paying billions to clean up today. All it will take is one small earth quake to rupture and degass these things, especially if they are planning on doing them so damn shallow. And also, by putting them so shallow you run the risk of ruining water reservoirs that alot of people depend on. I still think its a terrible idea, and if these idiots want to get serious about cutting back on CO2, they need to go after the source, not just hide it away for 50 years so our grandkids have to deal with it down the road.