In my previous missive, by 'direct air capture', I was referring to capture of CO2 from air in centralized industrial facilities.
On Fri, Mar 23, 2012 at 2:21 PM, Robert Tulip <[email protected]>wrote: > Hello Ken, > > I'm an advocate of direct air capture. I've followed this board for a > while and hope this is an opportune moment to comment. > > My view is that large scale ocean based algae production can provide a > geoengineering method that addresses both CO2 capture and solar radiation > management, producing commercially valuable fuel, food, fertilizer and > fabric in a method that is entirely ecologically sustainable. > > Algae production can combine the best features of Solar Radiation > Management and CO2 Capture in a method that is funded by production of > commercial commodities. Algae is the most efficient photosynthesis crop, > and can be produced in controlled ocean environments, using energy from > tide, wave, current, wind and sun to mimic the original process of > deposition of fossil fuel, at very low operating and capital costs, if done > on large enough scale. > > Please see my description at > http://rtulip.net/yahoo_site_admin/assets/docs/Algae_Biofuel_Feedstock_System_Provisional_Patent.285191915.pdf > > This is all public domain. I am more concerned about contributing to > public goods than anything else. I just want to know if these ideas are > feasible, so would welcome expert comment. My estimate is that controlled > algae production on 0.1% of the world ocean could stabilise the global > climate and deliver a path to steady reduction in CO2 concentration, > through sustainable fuel, food, fabric and fertilizer production. > > Kind Regards > > Robert Tulip > > Program Manager > Mining for Development > Australian Agency for International Development > www.ausaid.gov.au > > > *From:* Ken Caldeira <[email protected]> > *To:* [email protected] > *Cc:* Geoengineering <[email protected]>; > [email protected]; Howard Herzog <[email protected]>; John > Schellnhuber <[email protected]> > *Sent:* Friday, 23 March 2012 10:16 PM > *Subject:* Re: [geo] Calgary meeting on Direct Air Capture - thoughts? > > *"So what is the DAC business model, why is venture capital interested, > and what does it have to do with stabilizing air CO2? " -- GH Rau* > > Greg, I think you hit the nail on the head. > > If we think of direct air capture as negative emissions, then air capture > is basically a more expensive way to reduce net emissions. > > So, the only plausible business model is serving activities where CO2 is > needed where direct air capture may be able to provide the CO2 at lower > cost (or at least more conveniently), i.e., the goal is to profit primarily > by providing CO2 as a commodity. > > You mention enhanced oil recovery (EOR), which of course involves a net > flux of carbon from geologic formations to the atmosphere. Another possible > application might be military applications where you want to make jet fuels > on a nuclear powered aircraft carrier using atmospheric CO2 and seawater. > > If the above framing is correct, then direct air capture is more about > seeking profits from oil companies and the military-industrial complex than > it is about reducing climate risk. > > As the IPCC concluded in its 2005 Special Report on Carbon Capture and > Storage, there just aren't enough products that need CO2 as an input for > provision of CO2 for industrial uses to be a significant contributor to > climate risk reduction. > > If EOR is really a primary target application, then direct air capture is > more about increasing atmospheric CO2 concentrations than it is about > decreasing atmospheric CO2 concentrations; it is more about increasing > climate risk than decreasing climate risk. > > It would be interesting to hear from the direct air capture companies > whether they see themselves as being in the business of climate-risk > reduction, and if they answer in the affirmative, it would be interesting > hear their rationale. > > > > _______________ > Ken Caldeira > > Carnegie Institution Dept of Global Ecology > 260 Panama Street, Stanford, CA 94305 USA > +1 650 704 7212 [email protected] > http://dge.stanford.edu/labs/caldeiralab @kencaldeira > > *YouTube:* > <http://www.youtube.com/watch?v=a9LaYCbYCxo>Climate change and the > transition from coal to low-carbon > electricity<http://www.youtube.com/watch?v=a9LaYCbYCxo> > Crop yields in a geoengineered > climate<http://www.youtube.com/watch?v=-0LCXNoIu-c> > > > > > On Fri, Mar 23, 2012 at 3:35 AM, RAU greg <[email protected]> wrote: > > Ron, > Thanks for asking:**** > ** ** > 1) Wasn't invited to Calgary.**** > ** ** > 2) As Socolow et al and more recently House et al. PNAS 108:20428–20433 have > shown, if your game is removing CO2 from air, concentrating molecular CO2 > from air is probably the last thing you want to do because of the > prohibitive thermodynamics and hence cost. But what really irks me about > the DAC crowd is they act as though they are inventing air capture, e.g., > the Economist article's subtitle that gushes: > "The idea of pulling carbon dioxide out of the atmosphere is a beguiling > one. Could it ever become real?" > or Marc Gunther's quote: > "Most scientists believe removing CO2 from the air is expensive and > impractical to do on a global scale." > Let me be the first to break the good news; air capture is occurring all > around us, to the tune of about 17 Gt CO2/yr. That's right, the equivalent > of about 57% of anthro CO2 emissions is thankfully already being removed > from air by natural process for free. I'd say that is a pretty good example > of effective, low cost, global scale air capture, in contrast to the > latest $1000/tonne CO2 figure of House et al. So, if one is interested in > increasing air capture, the obvious places to start are figuring out how > to 1) increase global photosynthesis (afforestation, ocean fetilization), > 2) decrease respiration of biomass (biochar), or my favorite, 3) increasing > mineral weathering rates. Then there are hybrids of 1 -3. Why start with a > highly artificial and expensive process of concentrating molecular CO2 when > nature provides much lower cost and less risky examples that are already in > global scale operation? **** > ** ** > 3) Haven't read Marc's ebook, but assume it's along the lines of the > Economist article. Perhaps he'll send me a free, autographed copy**** > ** ** > 4) See above. I've submitted a followup letter to PNAS, for what that's > worth. > ** ** > 5) Good point - why insist on concentrated, molecular CO2 as your end > product? Nature doesn't. One has to conclude that EOR is their end game, > in which case this generates a net air CO2 source rather than a sink: In > standard CO2-EOR, 3 tonnes of CO2 are generated from product per tonne of > CO2 injected. You can be sure that oil companies will want to increase > (worsen) this 3/1 ratio if they are paying >$100/tonne CO2 injected. > Traditional geologic sources of CO2 for EOR are less than 1/10th this cost. > > > So what is the DAC business model, why is venture capital interested, and > what does it have to do with stabilizing air CO2? Any Calgarians care to > fill us mortals in?**** > ** ** > Your humble messenger,**** > Greg > ** ** > > > > *From:* "[email protected]" <[email protected]> > *To:* Geoengineering <[email protected]> > *Sent:* Thu, March 22, 2012 3:41:23 PM > *Subject:* [geo] Calgary meeting on Direct Air Capture - thoughts? > > List: > > 1. I thought this list had a very useful dialog a few months ago on the > CDR technology called Direct Air Capture (DAC - sometimes "Artificial > Trees"). I have just become aware of an invitation-only meeting on this > topic - hosted by the group "ISEEE" at the University of Calgary on March 6 > and 7. A preliminary agenda is available at: > http://www.iseee.ca/dacs/ > > 2. Two useful recent descriptions of the dialog are given at: > http://www.economist.com/node/21550241 > and > > http://www.marcgunther.com/2012/03/11/direct-air-capture-of-co2-is-becoming-a-business-for-better-or-worse/ > > > 3. Marc Gunther also had an article on the major DAC companies just as > the meeting was starting at: > > http://chimalaya.org/2012/03/06/rethinking-carbon-dioxide-from-a-pollutant-to-an-asset/ > > 4. I gather from this material that Prof. Socolow was under > considerable pressure to lower his (and APS') decidedly negative projection > on costs. I wonder if any list member in attendance can comment on this > controversy - that was covered nicely on this list. > > 5. I also gather there was considerable unhappiness in the present > emphasis of all (?) of these DAC companies away from CDR - and instead on > to uses of the captured CO2 for enhanced oil/gas production and for > combination with H2 for appreciably lower carbon footprint fuel > production. Any comments on these aspects - or any other part of the > meeting? > > Thanks in advance for any additional information. > > Ron > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > 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. > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > 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. > > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > 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. > > > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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