Dear Dr Rau, Thank you for your response towards our research, I appreciate your comments on our work. To explain about the saturation experiments; we tried to saturate the CO2 within water and with and without the nanoparticles present in the system and found that there was more CO2 in the nanoparticle solution in that of pure water.We do not claim in the paper that we are getting CO3-- in our system at all. We have observed that the concentration of the acid in the nanoparticle solution is higher than that of pure water. We observed that here was HCO3- species on our nanoparticle surface and the possible explanation (for this increase) we suggested was that there might me adsorption of HCO3- ions (from the acid) on the nanoparticle surface. As all this is happening at a pH in the acidic range (<5) thus according to chemistry of CO2 in water at this pH range there is acid system and none of the basic system of bicarbonates or carbonates exist.
As mentioned by Dr Siller, previously we are yet experimenting on the method of carbonate mineral formation with; possibly silicate sources. We do not tend to use sea water or oceanic system in our work at all. The idea to use Nickel for this reaction was taken from the sea urchin studies conducted by Dr Siller and other my other colleagues. We do not dump anything into the sea or use the oceanic system into the process. We suggest using a mineral source (terrestrial) for the metal ion (Ca2+ or Mg2+) to form corresponding mineral carbonate. The concept is to use it as a satellite unit for point source emission (power plants for example) trapping. On Thursday, 7 February 2013 18:49:41 UTC, Greg Rau wrote: > > Thanks for responding. I really don't follow this. If I have a beaker > of water fully equilibrated with air (CO2) and add your Ni particles, you > are saying that more HCO3- and ultimately CO3s will spontaneously be > produced. This won't happen unless thermodynamically favored, and if that > water if fully equilibrated with air CO2 there is no thermodynamic > condition that will force a change in the C chemistry. If your Ni > particles are somehow consuming H+ or producing OH- then you've got a > driving force, but you still need a source cations to make CaCO3s (am > very interested to learn how you cheaply extract cations from silicates.) > Otherwise, adding a catalyst to a system at thermodynamic equilibrium does > nothing. On the other hand, adding something to seawater that overcomes > the natural, chemical inhibition of abiotic CaCO3s precipitation could > really cause some serious precipitation and CO2 injection into the > atmosphere. No? > -Greg > > From: "[email protected] <javascript:>" <[email protected]<javascript:> > > > Reply-To: "[email protected] <javascript:>" > <[email protected]<javascript:> > > > Date: Thursday, February 7, 2013 8:32 AM > To: geoengineering <[email protected] <javascript:>> > Subject: [geo] Re: Nickel nanoparticles catalyse reversible hydration of > carbon dioxide for mineralization carbon capture and storage - Catalysis > Science & Technology (RSC Publishing) > > > With presence of Ni we have increases at the same time trapping of CO2 > and increased the rates of conversion to carbonic acid on room temperature > and on the atmospheric pressure. > We still working to find the best mineralisation pathway - we will use > silicates (magnesium calcium silicates) as a source of Ca2+ or Mg2+. > > While nickel nanoparticles are toxic as already mentioned in the paper we > do not propose to spread this around in the enviroment but to have local > disposal next to power plant or industrial plant. > We made brief cost - 8$ per ton of CO2 if we can recover Ni 99% yield > based on current price of nickel. > > > > > -- > 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 [email protected] <javascript:>. > To post to this group, send email to [email protected]<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 [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
