Numerical Analysis on Heavy Water Separation Characteristics for a Pair of Dual Temperature Multistage-Type H₂/ H₂O-Exchange Columns

Abstract

In order to study the separation characteristics for a pair of dual temperature mul-tistage-type H₂/H₂O-exchange columns, each stage of which is composed of the scrubbing packed bed for the water/vapor isotopic exchange and the hydrophobic Pt catalyst bed for the vapor/hydrogen isotopic exchange, the authors tried to compose the finite difference equations considering the water/vapor isotopic exchange and the vapor/hydrogen isotopic exchange and then made it possible to calculate the D-content in the water, vapor and hydrogen at any point in a pair of dual temperature multistage-type H₂/H₂O-exchange columns by way of six variable one order matrix equation derived from the six boundary conditions.
Utilizing the results mentioned above, the authors tried a further study to get an optimum value of hydrogen/water molar flow ratio, number of stages in a cold column and a hot column, degradation ratio ((Z^W_B - Z-^W_F)/Z^W_B) and specific volume (m³/kmol D₂O•h) of a pair of dual temperature multistage-type H₂/H₂O-exchange columns, in an example case where the temperature in the cold and hot columns, the enrichment factor, the catalytic exchange efficiency and scrubbing efficiency were given at normal pressure.