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?