| The isotope exchange reaction between hydrogen and water by hydrophobia catalyst is an effective method to separate hydrogen isotope because of its mild operating conditions. It has many potential applications such as producing and upgrading heavy water, removing tritium from light water or heavy water, and recovery tritium for fusion reactor. A really effective hydrophobia catalyst with stability and high activity is the key to hydrogen isotope exchange reaction between hydrogen gas and liquid water.The activity and stability is directly affected by preparation technology of hydrophobic catalyst. The details of preparing hydrophobic catalyst keep secret in most countries, because of the commercial benefits. We must prepare a very high active and stable hydrophobic catalyst used in engineering.This paper mainly presents the design and preparation, characterization and the activity of hydrophobic catalyst, the process of f^-tbO liquid catalytic exchange reaction (LPCE), and the mass balance calculation combined electrolyte catalytic exchange (CECE) process.Two kinds of hydrophobic catalyst are prepared in this paper. One is Pt-SDB (Styrene- divinylbenzene Copolymer), which is prepared by depositing Pt directly on the hydrophobic resin SDB. The other is the kind of Pt-C-PTFE (Polytetrafluoro -ethylene), which is prepared by supporting Pt on the carriers such as active carbon, PTFE as the wet-proof material. In the same operating condition, the Pt-SDB catalyst has much higher catalytic activity than Pt-C-PTFE catalyst, and the volume transfer coefficient of Pt-SDB is nearly twice than that of Pt-C-PTFE.The activity of hydrophobic catalyst is affected by carrier and preparation technology. In order to improve the activity of hydrophobic catalyst, it must keep even . dispersion of the active metal platinum on carriers, because the degrees of dispersion of platinum particle on the hydrophobic carriers result in the difference of catalytic activities. The prosperities of SDB also affect the performance of Pt-SDB hydrophobic catalyst strongly. The results show that WSDB3 and NSDB are good carriers. High activity is obtained while the reducing temperature of Pt-SDB is about 200 癈, which isdifferent from the reducing temperature above 250 癈 on report. The activities of Pt-WSDB3 and Pt-NSDB hydrophobic catalysts reach the level of catalysts prepared in other countries. The Active metal platinum has ideal dispersion and the small crystallite. The average size of platinum crystallite is less than lOnm measured by hydrogen chemisorptions and X-ray diffraction and scanning electron microscopy.There are two kinds of Pt-C-PTFE hydrophobic catalyst classified by preparation method. One is Pt-C-PTFE hydrophobic catalyst prepared by mixing Pt- carbon and PTFE powder, the other is AhCb-Pt-C-PTFE hydrophobic catalyst, Pt-carbon powder were treated with PTFE fibers and then bonded to ceramic carriers, PTFE as wet-proofed and bonding material. The advantage of A^Os-Pt-C-PTFE hydrophobic catalyst is of high strength, big size and high value of using platinum, but it is difficult to coat Pt-C on the support of A^Os, while Pt-carbon and PTFE fibers keep good dispersion in the Pt-C-PTFE mixture. Platinum can deposit and disperse by adding little dispersant, which also can improve the binding force between Pt-C and A^Oa. Pt-C-PTFE hydrophobic catalyst which is reduced at the temperature of 350癈 over 8 hour has good hydrophobic nature and high activity, while the range of weight ratio of PTFE to Pt-C powder is from 1.0 to 2.0. The reductive degree at the said hydrophobic catalyst is 100% Pt (0) measured by XPS.We carried out the hydrogen-water isotope exchange reaction in counter-currently in the trickle bed. We tested the activity of the hydrophobic catalysts and discussed the effect of operating conditions on the activity, such as reacting temperature, flow rate of hydrogen, flow rate of heavy water, the height of catalytic bed, and so on. The results indicate that:The mass transfer rate between liquid and vap...
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