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he current power machines where solid polymer electrolyte/external reformer - based
fuel cells are applied need materials that would be able to separate H2/CO mixtures at
temperatures from 800 to 900 °C. The conventional techniques to separate these gases are based on
palladium metal molecular membranes applications; these techniques have a limitation in the gas
mixture temperature of 550 °C. The paper reports the tests of ceramic molecular membranes with
meso-porous structure of the mean diameter 7 nm allowing separation of high temperature H2/CO gas
mixtures. The initial experimental samples of the disc ceramic molecular membranes were
manufactured on the basis of zeolite ZSM-5. Nano pores were formed in the entire membrane volume
with the pore sizes required to separate CO from H2. Tests of the membranes were carried out using
a special purpose experimental "hydrogen" test bed with the flow temperatures higher than 800 °C
and pressures up to 2 Mpa. The water vapor effect on the membrane material could be also studied
here.
Membrane devices can be designed and manufactured basing on the developed and tested membranes. Such devices will give an opportunity to use natural gas instead of pure hydrogen expanding the application of solid polymer fuel cells in industry both as independent power sources and as a part of hybrid engines through which the efficiency of the power systems increased up to 55-65% and higher. |
full paper (pdf, 400 Kb)