The results of the comparative study of the effect of the method for structured packing pretreat ment (CY type Sulzer packing and rolled ribbon screw packing) on the effectiveness of mass exchange in the course of hydrogen isotope exchange in water rectification and its phase isotope exchange (PIE) are given. The latter process is used for the removal of tritiated water vapors from gases and its difference from rectifi cation involves that the irrigation density of packing by water is 50-150 times less under other comparable process conditions. This difference leads to the fact that, for the packings prepared from stainless steel, the coefficient of mass transfer ratio for two boundary cases, namely, its preliminary flooding by water or launch of column with dry packing, is nearly 50 for PIE and 2 for rectification. The use of CY type Sulzer packing for PIE process prepared from oxidized copper yields that this ratio for PIE becomes identical with rectifica tion. Based on the obtained results, the recommendations for the optimization of PIE column startup are given.

The main physical-chemical characteristics of ceramic high-porosity block-cellular catalysts coated with a palladium active layer in the process of oxidation of hydrogen under different experimental conditions are presented. It is concluded on the basis of the data obtained on the energy of activation and catalytic activity that in comparison with imported granular catalysts they hold promise for use in the catalytic oxidation of hydrogen isotopes.Ceramic high-porosity block-cellular catalysts of the oxidation of hydrogen isotopes with a platinum active layer, deposited by permeation from a solution of platinum-chlorine-hydrogen acid followed by reduction, have exhibited high efficiency [1] and a number of advantages over the commercial granular platinum catalyst JM (Great Britain) [2] in the process of hydrogen oxidation, which are mainly due to the characteristic arch-labyrinthine structure and strength of the ceramic framework [3,4].The aim of obtaining palladium catalysts, which are similar in terms of the structure and physical-chemical characteristics, for the oxidation of hydrogen isotopes on the basis of high-porosity ceramic cellular materials (HPCM), aside from lowering their cost of production as a result of the replacement of platinum by palladium, was to check the efficacy of a palladium active layer deposited by means of chemical precipitation [5].The characteristics of the samples of ceramic high-porosity block-cellular catalysts, containing a palladium active layer and metallic palladium in amounts no more than 1% (mass fraction) of the mass of the ceramic carrier, which are fabricated for performing tests in a catalytic hydrogen-oxidation reactor are presented in Table 1. This content of palladium in the experimental samples corresponds to the platinum content in the commercial granular catalyst JM (Johnson Matthey, Great Britain), also taken for comparison.Electronic photomicrographs of samples with a deposited palladium coating are presented in Fig. 1. They attest to the formation of a compact palladium coating on the surface of the cellular-mesh ceramic framework, where the coating consists of rough aggregates with an extended outer surface and an appreciable number of micropores. The cellular struc-