High Pressure Reforming and Hydrogen Purification for Military Fuel Cell Use

A high pressure water reforming (HPWR) reactor system was designed and constructed to operate at pressures up to 82,737kPa and temperatures up to 913K. Initial HPWR hydrogen production tests have been conducted with two feedstocks: an aromatics- and sulfur-free natural gas-derived fuel (S-8) and methanol. Feedstock and water were continuously pumped into a reactor vessel where they were catalytically reformed to a hydrogen-rich reformate product. Reactor temperature, pressure, and space velocity were varied to determine their effect on reformate hydrogen concentration. Online, Raman spectroscopy gas composition measurements were verified by gas chromatography. Experiments conducted to date have resulted in a S-8-derived 33,784kPa reformate containing 58 mol% hydrogen at 898K, and a methanol-derived 33,784kPa reformate containing 76 mol% hydrogen at 638K. To enable high-pressure purification of HPWR-generated reformate to proton exchange membrane (PEM) fuel cell-quality hydrogen, EERC researchers have been working to tailor a low-pressure Oak Ridge National Laboratory-developed electrical swing adsorption (ESA) technology for high-pressure separation of hydrogen from other reformate constituents. Reformate purification experiments conducted to date have achieved quantitative separation of hydrogen from a bottled gas mixture of carbon monoxide, carbon dioxide, and methane at 1,379kPa. Near-term future experimental work will focus on 1) optimization of the HPWR process using sulfur- and aromatics-free jet fuel, and then JP-8 fuel, at pressures of up to 34,474kPa and 2) optimization of the ESA process for hydrogen purification at pressures of up to 34,474kPa. Results of these experiments will be presented.