Some features of the dual-temperature method of separation of hydrogen isotopes

Institut of The Radiation and Phys. Chem. Biologie, Acad, of Science, U.R.S.S., U.R.S.S..

Abstract

1. The two-temperature isotopic hydrogen exchange between liquid water and countercurrent gas which forms the basis of the most economical method to produce heavy water is practically effected not between pure substances but between two-component phases : the satured gas solution in water and the gas mixture with saturated water vapours.

2. The effect of the bi-componency of phases on the process of two-temperature isotopic hydrogen exchange has been analysed and equations worked out for the exchange between the gas-vapour mixture and the gas solution when the exchange rate in the solution is sufficiently fast.

3. The enrichment curves have been calculated as exemplified by the scheme of the two-temperature exchange in the system water-hydrogen chloride (where the effect of the bi-componency of phases is rather strong).

4. The process of the enrichment of deuterium in this system (hydrochloric acid-gas vapour mixture of hydrogen chloride with water) at t₁ = 17 °C, t₂ = 90 °C, P = 1 atm. has been experimentally investigated.

5. It has been shown that the bi-componency of phases may lead to a shift of the enrichment maximum beyond the ratio of currents, equal to the value of the distribution coefficient (α) of deuterium. The enrichment maximum in the system under study lies in the range 2.8 to 2.9, whereas the highest value (for a cold column) at 17 °C is 2.53.

6. The ratio of the height equivalent to a theoretical plate (HETP) for rectification of water and HETP for the twotemperature exchange has been determined and found to be for the system under study about 0,4.