(28a) Hydrogen Separation From a Gas Mixture with a Polymer Membrane

The establishment of alternative energy sources, which allow the use of renewable and ecologically safe energy, is one of the greatest challenges in the 21st century. An energy carrier with big potential is hydrogen. This work covers the possibilities of hydrogen separation from a gas mixture with a membrane process.

Suitable membrane polymers are discussed and the permeation of gases based on the solution-diffusion-mechanism is explained.

The membranes were produced with two different methods out of polymer solutions. The preserved membranes were evaluated concerning the surface homogeneity, the thickness distribution and the permeation characteristics. The results indicate that the solution-casting process is suitable for producing high quality membranes.

The membranes were characterized in a membrane reactor. The experiments allowed the realization of two often used methods: the time-lag-measurement and the pure-gas/gas-mixture-measurement. With these measuring methods gas permeabilities for the gases H2, N2 and CO2 were determined. Based on these results the used polymers were evaluated concerning the suitability as membranes for the hydrogen separation. Polyimide showed excellent separation properties towards hydrogen.