Comments on: Nitrogen trifluoride as an anthropogenic-greenhouse-forcing gas.

By: George E. Smith

George E. Smith — Thu, 30 Oct 2008 18:11:03 +0000

Just got googled over to your site; and very happy to be seeing the same queries I came over here for. Where the blazes is the IR or any absorption spectrum for this stuff.
Also, if the earth’s IR emission spectrum ranges from about 40-240 meV photon energy, just what is the capture crossection of NF3 for that energy range.
How can anyone be claiming a 17,000 times potency whatever the heck that means in plain science terms; and just what does the 100 year tiem scale have to do with anything; do these molecules simply get tired after a while and quit absorbing.
Such balderdash that is being thrown about in this so-called climate “Science” community.

There’s that other little problem; as of July 1 2008 according to a paper I just received from Scripps; the abundance of NF3 in the atmosphere on a dry air molecular basis, is “reliably” claimed to be 0.454 part per trillion.

That means if there were no other pollutants in the atmosphere but NF3, the air would be 99.9999999999546 % pure.

That is about 200,000 times the purity of the most pure semiconductor industry chemical reagents,a nd raw materials such as raw Gallium and Arsenic. Don’t know what current silicon purity is; but it is likely in the same range.

We are talking about a species that could be many metres between molecules of the same species in the atmosphere. What utter nonsense.

By: Hank Roberts

Hank Roberts — Sat, 05 Jul 2008 20:27:25 +0000

Did you try the link provided? You’ll need to go to a library if you’re not an AGU member of course. Interlibrary loan is good.
http://www.agu.org/pubs/crossref/2006/2006GL026210.shtml

By: sunsettommy

sunsettommy — Sat, 05 Jul 2008 20:19:27 +0000

LOL,

It is sure funny that they are so worried about the alleged warm forcing power as claimed.When there appears to be no data showing it’s actual role spectrally.

That is why I was immediately skeptical.I will remain that way until I see real spectral data and the corresponding frequencies.

It should have been obvious that when publishing claims that NF3 has “As a greenhouse gas it is 17,000 times as potent as carbon dioxide, molecule-for-molecule,…”.They should have shown the spectral of it as well in the IR window.

Thank you for trying to find some spectral data for it.

By: Luke Weston

Luke Weston — Sat, 05 Jul 2008 05:37:33 +0000

That’s a good question. I’d like to see the actual absorption spectrum, however, since we know unambiguously that many compounds containing C-F bonds, as well as S-F bonds in the case of sulfur hexafluoride, have molecular resonances corresponding to IR wavelengths.

I checked the Sigma-Aldrich catalog online, since they usually provide FTIR and all the usual spectral data for everything they stock, but they don’t have it.

Since it’s inorganic, sadly it might be a little trickier to find a literature reference for the IR spec.

By: sunsettommy

sunsettommy — Fri, 04 Jul 2008 17:13:22 +0000

I fail to find the information on actual spectral analysis of NF3.

Does it have a frequency band in the IR window of the spectrum?

I have been looking for it and not find it.Seems strange that there is all that talk about how powerfull a greenhouse gas it is and not be able to find the spectral bands in the IR window for it.

By: Luke Weston

Luke Weston — Thu, 03 Jul 2008 22:58:52 +0000

Thanks for the comment Lamy, it’s very interesting stuff.

By: truthwalker

truthwalker — Thu, 03 Jul 2008 22:13:03 +0000

Actually the solar panel industry is aware of the enormous pollution impact of solar panels. Gaiam Co. (http://www.gaiam.com/) rates the panels it reviews by how long it takes them to produce as many KW of emission free power as it took KW of normal power to manufacture them. They don’t consider photovoltic panels zero emissions till they pay of this “emissions debt”. Standard is currently about 15 – 25 years. Its not perfect, but its a step of accountability in the right direction.

By: Lamy Chopin

Lamy Chopin — Thu, 03 Jul 2008 20:07:23 +0000

Interesting post. I know a fair amount about plasma TV manufacture and I was quite surprised to see a mention of NF3 in the process. You are correct that any association of NF3 and plasma display panels (PDPs)must be due to misunderstanding of the technology. In fact, PDPs are made almost entirely by a screen printing technology that is closer to how they make T-shirt designs than it is to semiconductor manufacturing (which, as you note, is where the NF3 comes in). Basically the panels are made from a series of printed layers, with each ‘pigment’ in the printing process serving as a different functional component. Thus, a different pigment might produce a conductive element, a dielectric element, a phosphorescent element, or a structural element. Most of these pigments are basically low melting point glasses, and the rest of the ‘ink’ is simply a solvent (derived from pine trees, actually), and a resin binder (also derived from cellulose). After printing, the panel is fired like a ceramic, and the solvent and binder are burned away. So the process uses some energy, and makes some CO2, but overall it’s probably a lot cleaner than the old CRT fabs.

I’m not an expert on semicon fabs, but as a chemist I expect that all of the NF3 is readily consumed in etching processes. You get some silicon fluoride out and a fair amount of nitrogen gas. Don’t recall nitrogen having a serious greenhouse potential! So unless there is a leaky process, NF3 is a minor worry.

By: Robert Merkel

Robert Merkel — Thu, 03 Jul 2008 19:53:25 +0000

Interesting – this is something I should have known, but didn’t!

I’ll have to check whether they factor these into life cycle analyses of solar panels.