(95f) Membrane Reactor Methanol Reformer

PEM fuel cells are potentially highly efficient power sources for soldier-portable power systems and other military power production equipment, as well as for many consumer devices a major drawback that prevents the widespread use of PEM fuel cell technology is the lack of compact units to store the hydrogen gas essential for their operation.  One way to avoid hydrogen storage is to produce hydrogen on demand using compact fuel processors. Sulfur-free fuels, such as methanol offer significant advantages, simplifying the fuel processing.  Methanol can be reformed at low temperatures.  However, the hydrogen produced by fuel reforming will always be contaminated with diluents (such as nitrogen or CO₂) and a major anode electro-catalyst poison (CO).  It is necessary to remove CO from the hydrogen feed to ensure the long-term stable electrochemical operation of the fuel cell.

A membrane reactor-reformer to provide a high purity hydrogen fuel that could be readily used by fuel cells was developed.  THis system integrates the membrane steam-reformer module with a highly effective methanol reforming catalyst to combine the hydrogen production and gas processing steps into one process.  Both the new catalyst and the membrane reduce the amount of water to be stored by achieving sub-stoichiometric reforming of methanol.  This demonstrates the methanol-membrane reformer in a breadboard system; this showed the performance of the catalyst and the membrane integrated in the same module to produce high purity hydrogen through several heat-up/ cool down cycles and 72 hour missions with no degradation in the performance of the membrane or the catalyst. In this paper, we will present the results of the demonstration tests.