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View Full Version : D2O, Heavy water distillation

brejnev1960
January 19th, 2005, 03:57 PM
It's known that heavy water boils at a higher point than regular (light) water. It boils at 101.42°C according to Wikipedia.

Is it then possible to extract heavy water by boiling until you have about 0.0115% (it's concentration/natural abundance according to http://www.webelements.com/webelements/elements/text/H/isot.html) of the original volume left?

This seems to me like the most simple manner to manufacture heavy water at home.
Would this be usable for home production?
Zeitgeist
February 10th, 2005, 08:22 AM
Distillation or electrolysis down to 0.0115% of the original volume works.

Look up the Girdler Sulfide process, it's also interesting
Boomer
February 10th, 2005, 01:20 PM
"Distillation or electrolysis down to 0.0115% of the original volume works"

Hardly with normal eqipment. The boiling points are so close you have only slightly more D2O in the last drop than at the beginning. You would need a monster-column to have ANY uesful concentration after WEEKS of destilling under NEARLY COMPLETE reflux!

Xylenes are much further apart in boiling point and are not seperated by distilling.

Why not go by density, the difference is greater than for U235/U238.
akinrog
February 10th, 2005, 01:45 PM
Electrohydrolysis is more feasible than boiling I believe. There is a slight difference between standart cell potential of H+ and D+. I believe deuterium is produced by means of electrohydrolysis. I shall dig it up standard cell potential of two substances.
Pb1
February 11th, 2005, 10:32 PM
@brejnev1960: You seem to be a little confused about distillation. When your boil a mixture of any two substances, you don’t get vapor that consists completely of the more volatile substance. Instead, you get a mixture which has to be separated by fractional distillation, i.e. distilling through a column and sending back a portion of the material that gets through the column.
akinrog
February 12th, 2005, 11:31 PM
A few links about the issue.
This link (http://www.cns-snc.ca/Bulletin/A_Miller_Heavy_Water.pdf) gives a comprehensive description of the methods used to enrich (and extract) deuterium from normal water. The most admiring method referred to in that pdf is laser extraction method. (But I must admit that it more technical for an amateur).

The Girdler sulfid method also seems feasible to me. HTH