GB967000A - Method of deuterium enrichment of hydrogen or for the production of heavy water - Google Patents

Abstract

In a dual-temperature hydrogen/water isotope exchange system in the presence of a catalyst, for the deuterium enrichment of hydrogen or the production of heavy water, a stage of isotope exchange takes place between liquid water and hydrogen in counterflow in a cold first column and after vaporization of the water issuing from the cold column the steam thus formed is passed into a second column in concurrent flow with hydrogen for a further stage of isotope exchange. The cold column preferably operates at a temperature below 100 DEG C., e.g. 20-50 DEG C., and the hot column preferably between 300 DEG and 700 DEG C., and the two columns may form part of a cascade system of such columns. In the cold column the catalyst is suspended in the liquid water, and in the hot column is either in the form of a fixed bed or is maintained in suspension by the whirling motion of the hydrogen and steam. Suggested catalysts are nickel on chromium oxide or platinum on active carbon, and the catalyst from the cold column may, after evaporation of the water in which it is suspended, may be returned to the column, <PICT:0967000/C1/1> with or without regeneration. Referring to the drawing, liquid water leaving the bottom of the cold column 1 is evaporated in 2, the separated catalyst returning via 5 to the top of the cold column, and the so-formed steam then undergoes isotope exchange in concurrent flow with hydrogen in hot column 3, the hydrogen originating from the top of cold column 1. The mixture of hydrogen leaving 3 is separated in condenser 4, the impoverished water fraction being discarded or fed to a lower stage of a cascade system, and the hydrogen being returned to the lower end of column 1, where it undergoes countercurrent isotope exchange with liquid water. Part of this hydrogen may be fed to a higher stage of a cascade system. Enriched water may also be removed between columns 1 and 3.