I have a copy I got from Dr. Siller. She said I could send it to anyone I felt like. I didn't ask for and don't have her permission to post a copy for public access. Anyone wishing to see the paper, email me.
On Sunday, March 10, 2013 9:05:17 PM UTC-7, Greg Rau wrote: > > Anyone have an e-copy of Siller and Bhaduri? > Still unclear how catalysts are a panacea for CO2 air capture. There still > needs to be a chemical driving force that transfers gas into solution and > keeps it there. Adding CA, nano particles, etc to water doesn't magically > consume CO2. You've got to remove acid or add base to the solution to drive > the reaction. If you are talking about mitigating point sources, then > obviously pCO2 flue gas > pCO2 water is the driving force. Then keeping it > in solution requires some additional chemistry like adding a base. If > minerals are added as the base, carbonates would be must preferred over > silicates because of CO2 reaction kinetics. I can't imagine CO2 hydration > being the rate limiting step in most silicate weathering, so unclear how a > hydration catalyst helps here, but i should read the paper. > -Greg > ------------------------------ > *From:* geoengi...@googlegroups.com <javascript:> [ > geoengi...@googlegroups.com <javascript:>] on behalf of David Lewis [ > jrando...@gmail.com <javascript:>] > *Sent:* Thursday, March 07, 2013 3:38 PM > *To:* geoengi...@googlegroups.com <javascript:> > *Subject:* [geo] Re: Nickel nanoparticles catalyse reversible hydration > of carbon dioxide for mineralization carbon capture and storage OR Sea > Urchins May Save the World > > I was interested that Siller and Bhaduri, authors of this nickel > nanoparticle paper, compared what they think nickel nanoparticles can do * > favorably* to what carbonic anhydrase can do. > > A discussion of the properties and significance of carbonic anhydrase is > located on the Stanford website, i.e. at the Global Climate and Energy > Project, i.e. in this Jennifer Wilcox Carbon Capture 101 > Tutorial<http://vimeo.com/30557085>. > > > Wilcox devotes most of the tutorial discussing the best CO2 capture > chemistry presently commercially available, i.e. amine chemistry. * * > > As an aside, she brought up carbonic anhydrase at minute 34:30. A > transcript: > > "There is a special case called carbonic anhydrase. This is an enzyme. > This is how we filter out CO2 in our own bodies. So this is present in > the red blood cells of mammals. And essentially carbonic anhydrase is a > zinc based enzyme and you can see here there are three histadine groups > surrounding the zinc. And you have water associated with it. In solution, > the proton will go into solution and so you have this hydroxyl group > directly bound to the zinc and so what ends up happening is that OH will > hydrate CO2. So [garbled] its carbonate interaction with the OH of the > zinc, and the interesting aspect about this is that it occurs about ten > orders of magnitude faster. So CO2 to bicarbonate formation is up to ten > orders of magnitude faster than CO2 in aqueous solution without anything > added. That's just in water. * It can be anywhere from four to six > orders of magnitude greater than amine chemistry - for forming carbonate > from CO2. So it's a pretty significant enzyme*. Currently though the > source is questionable, where we can get this, since it is only available > in red blood cells. And, you know, that's limited. So there are a lot of > groups - there's a group at Columbia, there's a group at Lawrence Livermore > National Labs, working on synthetically making carbonic anhydrase as > additives for the absorption process for separation." > > I asked Siller for a description of the speed she and Bhaduri observed > nickel could catalyse CO2 to carbonic acid, in the terms Wilcox uses, i.e. > compared to CO2 in water, and/or compared to amine chemistry, i.e. CO2 and > amines in water. Her reply: > > "We have tried to determine the rates of conversion of CO2 to acid by > nickel nanoparticles with stop-flow technique to compare them with carbonic > anhydrase from the literature - however we have problems since nobody > before us did not work (sic) on this system and if we just copy literature > and try to use reagents which are used for CO2 capture by carbonic > anhydrase... the measured rates are unreliable.... So we are trying to > find the right reagents for kinetic measurements". > > I asked Klaus Lackner for his reaction about the importance of this > discovery that nickel acts similarly to carbonic anhydrase. He commented > on the Siller/Bhaduri plan to remove carbonic acid as it forms so the > nickel can continually produce more, by using olivine: > > "Keep in mind that other people have used bicarbonate brines to digest > olivine and they were rate limited too. These processes which start with > bicarbonate ions in the water end up being severely rate limited even > though they simply ignored the question of how to get the CO2 in the > water". > > I asked Siller what she thought of what Lackner brought up. Siller: > "we have some ideas we are exploring currently". > > Lackner also thought having a magnetic catalyst wasn't necessarily going > to be a game changer. "With regard to the ability to recover the catalyst. > Yes it is easy to pick up nickel magnetically, but the same will happen to > the iron that one invariably finds in the olivine rock. So magnetic > separation will leave you with an ever larger pile of magnetite". > > Siller: "if we do nickel separation before (have two tank process) we > would not need to worry about the iron". > > Lackner: "I am not entirely convinced that carbonic anhydrase could not > become similarly cheap, nor am I convinced that getting CO2 into the water > is the rate limiting step". > > Siller: "regarding the cheap carbonic anhydrase - this would be > great.... [however] it should be reusable and not easily degradable (this > would be probably harder to achieve when compared to inorganic catalysts > such as nickel nanoparticles). For nickel nanoparticles, process is easily > scalable - you can buy machine on the market now which will make Ni > nanoparticles." > > Siller: "conversion of CO2 to acid if you go through the chemistry > literature is* a* rate limited process". > > Lackner: "So I would argue this discovery seems to be a good piece of > progress. It is a very nice tool added to the tool box, but it may take a > lot more than that to actually solve the problem". > > DOE published Basic Research Needs for Carbon Capture Beyond > 2020<http://science.energy.gov/~/media/bes/pdf/reports/files/CCB2020_rpt.pdf> > which > starts out: > > "The problem of thermodynamically efficient and scalable carbon capture > stands as one of the greatest challenges for modern energy researchers.... > If scientists could develop practical and cost-effective methods to > capture carbon, those methods would at once alter the future of the largest > industry in the world and provide a technical solution to one of the most > vexing problems facing humanity". > > A few paragraphs later the document briefly describes why: "it is this > nexus of high-speed capture with high selectivity and minimal energy loss > that makes this a true grand challenge problem, far beyond any of today's > artificial molecular manipulation technologies, and one whose solution will > drive the advancement of molecular science to a new level of > sophistication". > > The DOE document is optimistic: "We have only to look to nature, where > such chemical separations are performed routinely, to imagine what may be > achieved". > > DOE mentions carbonic anhydrase. A sidebar explains that anhydrases > "are among the fastest catalysts known". They are cautious: "translating > this or other catalytic approaches to the challenging environment of a real > gas separation will require major advances in chemistry". > > > On Thursday, March 7, 2013 12:23:32 AM UTC-8, andrewjlockley wrote: >> >> http://pubs.rsc.org/en/content/articlelanding/2013/cy/c3cy20791a >> >> Nickel nanoparticles catalyse reversible hydration of carbon dioxide for >> mineralization carbon capture and storage >> >> Gaurav A. Bhaduri and Lidija Šiller >> >> Catal. Sci. Technol., 2013, Advance Article DOI: 10.1039/C3CY20791A, >> >> >> -- > 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 geoengineerin...@googlegroups.com <javascript:>. > To post to this group, send email to geoengi...@googlegroups.com<javascript:> > . > 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.
