[geo] Nickel nanoparticles catalyse reversible hydration of carbon dioxide for mineralization carbon capture and storage OR Sea Urchins May Save the World
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, The separation and storage of CO2 in geological form as mineral carbonates has been seen as a viable method to reduce the concentration of CO2 from the atmosphere. Mineralization of CO2 to mineral salts like calcium carbonate provides a stable storage of CO2. Reversible hydration of CO2 to carbonic acid is the rate limiting step in the mineralization process. We report catalysis of the reversible hydration of CO2 using nickel nanoparticles (NiNPs) at room temperature and atmospheric pressure. The catalytic activity of the NiNPs is pH independent and as they are water insoluble and magnetic they can be magnetically separated for reuse. The reaction steps were characterized using X-ray photoemission spectroscopy and a possible reaction mechanism is described. http://www.cornellsun.com/blog/content/2013/03/07/sea-urchins-may-save-world Sea Urchins May Save the World MARCH 7, 2013 BY CAMILLE WANG With global warming becoming an increasingly impactful issue, more and more avenues of resisting climate change are being explored. The latest answer? Sea urchins.Experts at Newcastle University, UK, discovered that sea urchins use nickel particles to convert carbon dioxide from the ocean into the harmless mineral, calcium carbonate. This capture of carbon dioxide, the key greenhouse gas responsible for climate change, could potentially play a key role in efforts against global warming. Researchers made the discovery “completely by chance.” They had initially been looking for a catalyst to speed up the carbonic acid reaction, which is the reaction between carbon dioxide and water. Simultaneously, they were also studying organisms capable of absorbing carbon dioxide in their skeletons, particularly sea urchins. Upon closer analysis, they discovered a high concentration of nickel on the exoskeleton of sea urchin larvae. The experiment of adding nickel nanoparticles to the carbonic acid test resulted in the “complete removal of CO2.”This process is advantageous in that it is less dangerous and less costly than other methods, such as pumping carbon dioxide in holes deep underground. Pumping carbon dioxide runs the risk of the gas leaking out. It is also a very expensive process.In regards to the nickel catalyst used by sea urchins, the conversion of carbon dioxide to carbonate is something that the earth has been doing for a very long time, according to Prof. Bill White, geochemistry. If scientists could scale up the reaction to remove substantial amounts of CO2, they would “be controlling climate just the way the earth has been doing it all along,” he said.“Seems like it often happens that we solve problems by recognizing and using nature’s own solutions. No question this would be a good thing in this case,” White wrote in an email.Prof. Charles Greene, Earth and Atmospheric Sciences, agreed that mimicking the processes of nature would be “fruitful,” but he questioned the significance of the impact of this finding.“It is hard to imagine that this particular [process] will be able to scale up to the capacity required — gigatons of carbon dioxide per year,” he said. “However, it should be explored. Hundreds of processes need to be explored because a vast majority will not pan 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.
[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 Tutorialhttp://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 therate 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 2020http://science.energy.gov/~/media/bes/pdf/reports/files/CCB2020_rpt.pdf which starts out: The problem of
