RE: [geo] New CO2 Sucker Could Help Clear the Air
The answer to Ken's rhetorical question is a qualified yes, if you ignore kinetics and assume you are looking only at the CO2 capture, desorption, clean-up and compression as he described then you can do it for pennies a kg of CO2 which is pennies per kWh. It's a yes because posed this way, ignoring kinetics and the capital and energy cost of the absorber this is the core of the standard engineering case for post-combustion CCS that has been analyzed endlessly for 20 years and for which there is lots of relevant commercial hardware. The qualification is around details of this particular material, but there are other solid and liquid systems that do this. For air capture it's harder because one cannot ignore the kinetics of uptake and the capital cost of the absorber structure. There is not much CO2 in the air so the contacting structure (the thing that actually gets CO2 from the air) must be very cheap. Here are some order of magnitude numbers: 1. You can't afford to move the air faster than a few m/s though the device (100 Pa= 6.1 kJ/mol-C= 13 m/s) 2. At that air flow, even if you get all the CO2 you are getting no more than of order 10 tCO2 m-2 yr-1. 3. Assume it is 10 tCO2 m-2 yr-1 and you don't want to pay more than 50 $/tCO2 for the amortized cost of the structure. Then the cost per square meter of inlet area must be less than 3 $k. (At 15% overall capital charge factor $3000 m-2 is $45 m-2 yr-1 which you then divide by the 10 tCO2 and round). This is hard. Large cooling towers are about $2000 m-2. 4. The amount of absorbing surface you need behind each square meter of inlet is depends on the kinetics of uptake, but at a mass transfer coefficient of 1 mm/sec one needs of order 500 m2 of surface area behind each 1 m2 of inlet. 5. For us a Carbon Engineering, using plastic packing it easy to meet this cost criteria as they cost 1$ per m2 of surface area. For our system packing cost is only a small fraction of contactor cost and a very small fraction of overall turn-key plant cost. 6. In order for a solid system to compete it must either have a much faster mass transfer coefficient or by roughly as cheap; and for a solid one must contrive a way to temperature or humidity cycle the whole solid structure cheaply and without significant air leaks. (Or find a way to gather the solids...). You can see some of our views about solid vs liquid systems at answer QA #8 at http://www.carbonengineering.com/wp-content/uploads/2011/04/CarbonEngineering-AirCaptureFAQ.pdf. Of course, the disadvantage of a liquid system is regeneration and management of liquid loss. The problems for solids are (a) getting fast uptake kinetics, (b) cycling given that the whole structure must be cycled either humidity swing or thermal swing, and (c) sorbent lifetime given that all the fancy solid must last for order a decade in air that contains contaminants such as particulates, trace gases and larger debris of all types. Bottom line: this looks like a real advance but without data on kinetics and long-term performance one can't judge how useful it is for air capture. In the near term we are reasonably confident that our liquid system will win for many large-scale air capture applications, but over the long run it's much harder to say what will happen. From: geoengineering@googlegroups.com [mailto:geoengineering@googlegroups.com] On Behalf Of Ken Caldeira Sent: Wednesday, January 11, 2012 1:47 PM To: r...@llnl.gov Cc: zen...@uci.edu; geoengineering Subject: Re: [geo] New CO2 Sucker Could Help Clear the Air Note that there is an error of 10^6 in the article, as it says 1.72 nmol when the underlying article (attached) says mmol. Here is my little order-of-magnitude analysis: At 1.72 mmol per gram of material, to process 1 ton of CO2, we have would need ~13 tons of polyamine. The 1 g of material absorbs at 25 C needs to be heated to 85 C for three hours to give off the CO2, so this is a 60 C swing. Of course, one thing conventional power plants have is a lot of waste heat. Once it gives off the CO2, it gives it off into some gas, so you still need to figure out how to separate the CO2 from this gas. [Or maybe you make a high vacuum, but how cheap is that? If you didn't want to go with a vacuum, what would be the gas that you would have it desorb into, in order to make that separation step easy?] The average CO2 intensity of electricity production is about 615 gCO2/kWh. So you would need about 8 kg of material per kWh of electricity. If the real process were to take 3 hours, then you would need about 25 kg of material per kW of plant capacity (or 25,000 tons per GW). Can you take 8 kg of material (enough for 1 kWh's worth of CO2), have it absorb CO2, heat it up and let it desorb into a vacuum or a gas (and if a gas, then separate the CO2 from whatever the gas it desorbed into), and then compress and bury it underground, for not more than a few pennies per cycle?
[geo] SRM testing, economic arguments
David (and list) , In Banff we debated srm testing costs. I made my point poorly and wish to clarify. The reason I think capital cost matters is because I don't think that government will grasp the nettle of research on a serious scale in the timescale required, because of the controversial nature of the subject. We may then be left trying to catch up research, whilst under huge pressure to deploy on a dangerously short timescale. To get a safe timescale, the research will likely have to be done with money and equipment funded by existing budgets and equipment inventory, and/or supported by 'greenfinger' benefactors. We can't wait for government to fund critical testing with new funding arrangements. Micro-cost geoengineering experiments are therefore critical to fast research. Brightwater, balloons, shells and smoke rings are all viable technologies for experiments funded by small departmental budgets and private donors. They may prove not to be as good as aircraft in certain respects , but as money is not immediately available for aircraft, we don't have the luxury of that choice. As a result, I believe that the focus should move to the technologies which we can test for tiny sums. We cannot afford to wait for 20 years of bureaucracy before testing a technology that may be needed in a hurry. If we wait for funding before we test, we may end up deploying half-baked technology. IMO, we should build our technology now, quickly and cheaply, so it is properly tested and ready to scale when the politicians come knocking. We cannot afford delays in our quest for knowledge. I don't want to be designing a parachute after I've jumped out of the plane. A -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
[geo] Re: New Geoengineering Target: Greenland Ice Sheet Snow Cover Whitening
Our research has shown that assessments of Greenland reflectivity change based on MODIS data are problematic. We have looked for darkening trends with MODIS and statistically speaking, we find a hint but nothing definitive. The image shown mentions darkening in 2011 relative to a six-year climatology, but does not mention the significant interannual variability of Greenland's albedo. Nevertheless, the work is suggestive of a trend which we expect to see someday, that is, temperature-snow metamorphism-albedo-temperature feedback. However, precipitation (fresh snow) could simultaneously increase and damp or overwhelm this signal. As to the long term trend of Greenland-wide albedo, the more trustworthy data are from CERES not MODIS (MODIS is better for hi-res. spatial patterns than for absolute albedo, because of problems retrieving snow albedo at large solar zenith angles such as are the norm in Greenland). Disclaimer: the MODIS surface reflectance team may disagree (to put it mildly) with these opinions. Wang, X., and C. S. Zender (2010), MODIS snow albedo bias at high solar zenith angle relative to theory and to in situ observations in Greenland, Rem. Sens. Environ., 114(3), 563-575, doi:10.1016/j.rse. 2009.10.014. Wang, X., and C. S. Zender (2010), Constraining MODIS snow albedo at large solar zenith angles: Implications for the surface energy budget in Greenland, J. Geophys. Res. Earth Surf., 115, F04015, doi: 10.1029/2009JF001436. On Jan 10, 7:54 pm, Veli Albert Kallio albert_kal...@hotmail.com wrote: Whitening of Greenland's snow cover is a new potential geoengineering target that we haven't discussed. Greenland Ice Sheet has been discovered darkening in 2011 with a new positive feedback in as follows:http://eoimages.gsfc.nasa.gov/images/imagerecords/76000/76916/greenla... It is very remarkable that this darkening has occurred since 2000-2006 and in some areas it is ~20%. Micromechanics of the snow cover darkening is explained here (analogous to snow crystals in the sky):http://earthobservatory.nasa.gov/IOTD/view.php?id=76916src=fb -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
[geo] Charitable donations for geoengineering research
It would be useful, as a matter of record, to have on this list any institutions which currently accept donations specifically earmarked for geoengineering science or policy research. At present it is unclear to me if any labs or organisations are able to accept donations from members of the public. I'm sure that there are many legitimate uses for such funds - eg funding PhDs, buying computer time, journal page fees, conference sponsorship, delegate travel bursaries. Could anyone who has details of such an opportunity for donations please reply to the list? A -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
Re: [geo] Charitable donations for geoengineering research
I believe we are able to accept such donations and would be happy to do so. http://carnegiescience.edu/giving-opportunities I believe we can accept donations earmarked for specific purposes. (If the demands are too cumbersome, we can always decline.) The normal form just let's you specify down to the department level, not the project level. However, I think a phone call or an email would be enough to specify the subject area to which the funds should be applied. --- That said, I am not a lawyer and am not speaking on behalf of my institution. For big donations, we can develop specific signed agreements about how funds would be used. For small donations, my guess is the institution would allocate the donation to the project requested by the donor, but would not want to open themselves up to potential frivolous lawsuits examining exactly how tiny donations were spent. (If you want to damage an organization, donate $10 for a specific purpose and then sue them in small claims court claiming they mis-spent the money, and then make them go through all kinds of maneuvers to document exactly how the $10 was spent.) ___ Ken Caldeira Carnegie Institution Dept of Global Ecology 260 Panama Street, Stanford, CA 94305 USA +1 650 704 7212 kcalde...@carnegie.stanford.edu http://dge.stanford.edu/labs/caldeiralab @kencaldeira On Thu, Jan 12, 2012 at 3:30 PM, Andrew Lockley andrew.lock...@gmail.comwrote: It would be useful, as a matter of record, to have on this list any institutions which currently accept donations specifically earmarked for geoengineering science or policy research. At present it is unclear to me if any labs or organisations are able to accept donations from members of the public. I'm sure that there are many legitimate uses for such funds - eg funding PhDs, buying computer time, journal page fees, conference sponsorship, delegate travel bursaries. Could anyone who has details of such an opportunity for donations please reply to the list? A -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. 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 geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
Re: [geo] Charitable donations for geoengineering research
I (Indian Institute of Science) would be happy to receive funds to do research in geoengineering science (modeling). Bala On Fri, Jan 13, 2012 at 5:00 AM, Andrew Lockley andrew.lock...@gmail.comwrote: It would be useful, as a matter of record, to have on this list any institutions which currently accept donations specifically earmarked for geoengineering science or policy research. At present it is unclear to me if any labs or organisations are able to accept donations from members of the public. I'm sure that there are many legitimate uses for such funds - eg funding PhDs, buying computer time, journal page fees, conference sponsorship, delegate travel bursaries. Could anyone who has details of such an opportunity for donations please reply to the list? A -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en. -- Best wishes, --- Dr. G. Bala Associate Professor Center for Atmospheric and Oceanic Sciences Indian Institute of Science Bangalore - 560 012 India Tel: +91 80 2293 3428 +91 80 2293 2075 Fax: +91 80 2360 0865 +91 80 2293 3425 Email: gb...@caos.iisc.ernet.in bala@gmail.com Web:http://caos.iisc.ernet.in/faculty/gbala/gbala.html --- -- You received this message because you are subscribed to the Google Groups geoengineering group. To post to this group, send email to geoengineering@googlegroups.com. To unsubscribe from this group, send email to geoengineering+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
