Patent ID: 7439273

Claim:
A hydrogen generation method comprising: generating a hydrogen-rich reformate gas at a temperature greater than 150 C. in a fuel reforming reactor; separating the reformate gas into a relatively pure hydrogen stream and an off-gas stream in a pressure swing adsorption (PSA) hydrogen purification unit, and converting carbon monoxide (CO) and at least a portion of hydrogen (H 2 ) contained in the relatively pure hydrogen stream into methane (CH 4 ) and water vapor (H 2 O) in a catalytic reactor down stream of the PSA unit; providing a first secondary purification stage downstream of the PSA unit and the catalytic reactor, the first secondary purification stage having a water adsorbent material bed that adsorbs the H 2 O; and a hydrogen absorbent (or adsorbent) material bed downstream of the water adsorbent material bed; concentrating the hydrogen into the hydrogen absorbent material bed; providing a second secondary purification stage downstream of the PSA unit and the catalytic reactor connected in parallel to the first secondary purification stage, the second secondary purification stage having a second water adsorbent material bed that that adsorbs the H20 followed by a second hydrogen absorbent material bed; and switching flow of the relatively pure hydrogen stream to the second secondary purification stage while desorbing the absorbed hydrogen gas from the first secondary purification stage; and switching flow of the relatively pure hydrogen stream to the first secondary purification stage while desorbing the absorbed hydrogen gas from the second secondary purification stage.