Thanks, David, very nice review. Where our technology departs from the higher profile abiotic methods you discuss is: 1) expensively concentrated CO2 is not formed (or stored), 2) reactions occur at ambient T and P - exotic chemicals and conditions are avoided (so far), 3) excess ocean rather than excess air CO2 can be mitigated, avoiding the need for more complex air scrubbing technology. Why go to the added expense/effort of getting air CO2 into solution to then do chemistry when vast areas of the surface ocean are already supersaturated in CO2? Doing the chemistry there completely avoids the giant land footprint and energy required for air scrubbing that you mention, as well as avoids the need for molecular CO2 sequestration or use. Obviously, the safety of doing this in the ocean needs to be researched, but generating ocean alkalinity would seem an improvement over our current ocean acidification "program". I'm not alone in my thinking; this builds on Kheshgi (1995), House et al. (2007), and Harvey (2008) among others. -Greg
________________________________ From: David Appell <david.app...@gmail.com> To: geoengineering@googlegroups.com Cc: m2des...@cablespeed.com Sent: Sun, June 2, 2013 10:55:22 AM Subject: Re: [geo] Re: Meanwhile, in CDR news... Mark: I have an article in this month's Physics World magazine that answers some of these questions: “Mopping Up Carbon,” Physics World, June 2013, pp. 23-27. http://www.davidappell.com/articles/PWJun13Appell-air_capture.pdf David On 6/2/2013 8:05 AM, Mark Massmann wrote: > I'm wondering if anyone can respond to these questions: > > I could be missing this, but how long is it estimated to take for the devices >to capture each ton of CO2? If the systems were installed to capture coal >plant >emissions, I'd imagine that the capture rate would be maximized. However >installing the systems outside of those sources might lower the capture rate >to >the point that the system becomes impractical (i.e. like installing a wind >farm >in a location that's simply not windy enough on average) -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to geoengineering+unsubscr...@googlegroups.com. To post to this group, send email to geoengineering@googlegroups.com. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out.