Unfortunately my confusion is only deepening ...
There is more CO2 in the np system - but I thought it was meant to be
H2CO3, not CO2.
There is HCO3- on the nickel - but no bicarbonate in the system.
If the solution is acidic (ie, there is lots of H+ in the solution),
where is the acidity coming from if not from dissociation of carbonic acid:
H2CO3 + H2O <=> H+, HCO3- <=> 2H+, CO3= ?
But you say only carbonic acid present.
Oliver.
On 07/02/2013 23:51, gaurav bhaduri wrote:
Dear all
Thank you for your interest in our work and your comments. To clarify
some of the misunderstanding in the process conditions that I'd like
to clarify. When we bubble CO2 in water with and without the
nanoparticles, we observed that there is more CO2 in the nanoparticle
system than in pure water. We also observed that there was HCO3- ions
on the surface of the Ni nanoparticles surface, we thus explained that
this enhancement could be due to adsorption of the HCO3- (from the
acid) onto the Ni surface. We in no place claim the formation of CO3--
ions, to be clear on this point the system we are addressing in this
article is at a acidic pH (<5). Thus there is only carbonic acid
species present no bicarbonate or carbonate system as they exist at
higher pH values.
Now coming to the point of mineralization. We are currently working on
this (as explained by Dr Siller, previously) and would like to use
silicates as our metal source (Ca2+ or Mg2+).
Regarding the confusion of sea or oceanic system. We do not tend to
imply the use of Ni nanoparticles in the ocean or any thing around it.
The relation with sea urchin (or the marine environment) is just that,
the use of Ni to study the hydration reaction we triggered by the
studies done on the sea urchin by Dr Siller and my other colleagues.
Our major application is to use this system as a satellite unit
(plant) to an operational point source emitter (for example a power
plant). The carbonate mineral thus produced would be used as landfill
or in any other useful application. As mentioned above, we are working
on the use of silicate sources (terrestrial) for the source of the
alkali earth metals (Ca2+ or Mg2+), thus ruling out acidification of
the ocean or any relation to the ocean.
Hope I was able to explain the application of our technology. If you
still have any doubts, please feel free to ask. We will try our level
best to clarify any confusion.
Thanks to all
Kind regards
Gaurav
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
<http://groups.google.com/group/geoengineering?hl=en>.
For more options, visit https://groups.google.com/groups/opt_out
<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.
--
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.
