From: gcowan@eagle.ca   
      
   Peter Fairbrother wrote:   
   >   
   > Ian Stirling wrote:   
   >   
   > > Paul F. Dietz  wrote:   
   > >> Henry Spencer wrote:   
   > >>   
   > >>> And indeed, the big snag is availability.  If you want a thousand tons of   
   > >>> xenon, you simply can't get it in any reasonable amount of time.  Even a   
   > >>> hundred tons would be problematic unless you order years ahead.  This is   
   > >>> essentially independent of the price you're willing to pay; even if you   
   > >>> outbid everyone else, there simply isn't that much production capacity.   
   > >>   
   > >> I'm sure if you wanted to spend enough money, you could get more, but   
   > >> the cost would be frightening.  Xenon is obtained as a byproduct of   
   > >> air liquefaction/separation, and is affordable only because almost all   
   > >> the cost is borne by the customer who needs the oxygen, nitrogen, etc.   
   > >> You'd have to build entire new air separation plants just for making   
   > >> the xenon.   
   > >   
   > > I was about to ask this earlier.   
   > > Does anyone happen to know what fraction of air seperation plants extract   
   > > the Xenon - as upgrading ones that don't might be cheap.   
   > > Also, what's the size of this sector?   
   > > I'd guess at tens of billions a year, in which case you'd probably need   
   > > to spend rather a lot to double or more capacity.   
   >   
   >   
   >   
   > Air is 1 part in 20 million xenon. If the recovery rate is 50% then to get   
   > 1,000 tons of xenon you would need to liquify 40 billion tons of air.   
   >   
   > If we generously estimate the present rate of worldwide air liquification at   
   > about 500 million tons pa (I think it's actually about 100 million tons),   
   > that's about 80 years production, if everyone recovers xenon.   
   >   
   > Air liquification is likely to decrease though, as PSA technology becomes   
   > more widely used for oxygen and nitrogen production.   
   >   
   > Xenon is also available in small quantities from some geological sources,   
   > wells and springs and suchlike, but that's a drop in the bucket.   
   >   
   > I had a quick look at some other potential air extraction methods, for   
   > instance chilling but not liquifying air (xenon boils at -108C), cold   
   > extraction with ?argon liquid, differential absorbtion, and venturi/cyclone   
   > methods; but there is just too little xenon in the air for the cheaper   
   > methods to work, and even the cheaper methods would be - expensive.   
   >   
   > Just fanning that much air into a gentle breeze would cost $100 million or   
   > so ...   
      
   Existing inventories of spent nuclear fuel   
   contain, I guess, hundreds of tonnes of xenon.   
   No fission-produced xenon isotope has a half-life longer   
   than a few days, but if krypton were co-extracted,   
   85-Kr would make the xenon hot.   
      
      
   --- Graham Cowan, former hydrogen fan   
   http://www.eagle.ca/~gcowan/Paper_for_11th_CHC.html --   
   how individual mobility gains nuclear cachet   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)