Hi, I'm the author of the seawater article. Thanks for your comments.
On whether or not its costly, I did try to construct as defensible a costing as possible, given that the carbon capture technology has not left the lab. The cost assumptions are described through the article, and at the end in more detail in the Appendix on costings. At the end of the introduction is a link to a spreadsheet containing the detailed cost calculations, so you can see what I've done. There are many caveats, but given the assumptions, which are largely those of the US Navy researchers, it turns out to be surprisingly cheap. For nuclear electricity generated from cheap Chinese nuclear build, the cost for carbon capture comes out at ~$40/tonne, and the cost of the synfuel derived therefrom is about 80 cents a litre. If you think this is unrealistic, what would be valuable would be if you can point to errors or omissions in the assumptions. Note too that the CO2 capture process is not a molecular separation from seawater, at least not in the sense that I think Greg meant. CO2 is not separated by a membrane process, and the seawater is not passed through a membrane. Instead, H+ is generated electrolytically on the membrane surface, and seawater is pumped *past *the membrane. The pH drops, and the CO2 bubbles out of solution to be captured. The acid stream is recombined with a base stream that was generated as a complement, and returned to the ocean. This is a very energy efficient, and clean process. The difference in power between this process and a true membrane separation process is huge. And without costing it, I imagine its cheaper than solar calcining of limestone. kind regards, john -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To view this discussion on the web visit https://groups.google.com/d/msg/geoengineering/-/xSn5RetUieEJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
