As noted in previous posts, I’m interested in the concept of storing CO2 in Antarctica as snow or ice. For an amount to store there, I came up with an amount equal to the nice round number of 100 ppmv. CO2 was below 300 ppmv before the industrial revolution and is at about 400 ppmv now. This works out to about
660 760 cubic kilometers or 200 cubic miles. I did not specify a time frame which I will do now. Half a century (50 years) sounds like another good round number and it’s only off from the old Soviet Union’s five year plans by one order of magnitude.
The point of this whole exercise is to get some idea of the scale of such an undertaking and I’ve come up with about
113 130 supertankers of liquid CO2 a day. The supertankers would be nearly 400 meters long and hold 320,000 cubic meters each (two million barrels of oil). I found this from Wikipedia. I don’t know how comparable a proposed liquid CO2 tanker would be to the oil tankers described, but it does give some idea of scale.
What if it were to be pipelined? I will also use an oil comparison. According to Wikipedia again, the proposed Keystone pipeline would move about 100,000 cubic meters a day (94,000 after the first two phases, 110,000 after the third phase). So I came up with a daily volume equivalent of about
360 416 Keystone pipelines. And needles to say, piping liquid CO2 is not the same thing as piping oil, but it does offer a sense of the huge scale. While it may never be practical, it does not look completely undoable. My simple calculations are below the fold.
(UPDATE: I mistakenly copied 760 cubic kilometers as 660. I’ve struck the old numbers. The new ones amount to only a 15% increase.)
Continue reading A Rate for Transporting CO2 to Antarctica
As I’ve explained in this post, I’m intrigued by the concept of storing frozen CO2 in Antarctica. I got interested in it by reading about this paper at Climate Etc. I’ve since learned a few interesting things about frozen CO2.
To make dry ice, CO2 is pressurized into a liquid. When this pressure is released, some of the CO2 evaporates and draws heat away from the rest of the CO2 causing it to freeze into snow. This snow is then pressed and shaped into dry ice. Most of the energy used is for liquefying the CO2. The implications of this for my plan to store CO2 as ice in Antarctica is that a lot of the energy used would not have to be expended in Antarctica. It would be used where the CO2 is collected and liquefied. This liquid would then be shipped or piped to Antarctica. The paper mentioned above calls for freezing and precipitating CO2 out of the air. My scheme would provide readily frozen CO2 and a rich source of CO2 gas that can be frozen and precipitated.
Another thing about liquid CO2 is that it maintains a constant vapor pressure. This makes it useful for things like CO2 cartridges for air guns. This might simplify the engineering of creating an infrastructure for piping and shipping liquid CO2.
I’m usually not very wordy, but I made a long comment on an open thread at Climate Etc. so I thought I’d make it a post here. I often wonder if CO2 is actually a serious problem whether it is possible to solve it by only cutting CO2 emissions.
Continue reading Long Comment at Climate Etc. on Whether Cutting CO2 is Enough
I once read this interesting post at Judith Curry’s blog, Climate Etc. It’s a rather fanciful scheme to precipitate CO2 out of the air in Antarctica and store it as snow, with the process being powered by wind turbines. I thought a better energy source for this would be nuclear power and even commented on it. Since then I’ve been intrigued by the concept of using nuclear power in Antarctica to freeze and store CO2.
So I thought I’d do some calculations to get some idea of the scale of such an operation. I picked 100 ppmv as a good round number for how much CO2 to store (pre industrial was below 300 and is now 400) and converted it to volume of dry ice. I came up with 760 cubic kilometers or 182 cubic miles. A huge undertaking to be sure, but it does not seem totally out of the range of possibility. Notes on my calculations are below the fold.
Continue reading How Much Dry Ice is 100 ppmv of Atmospheric CO2?