Continuous reactor

A method for removing carbon monoxide from a reactant stream, the method comprising:

• configuring a reactor to comprise:
• a first flow path defining a length and a preferential oxidation catalyst disposed therealong, said first flow path configured to convey carbon monoxide and hydrogen contained in said reactant stream;
• a second flow path configured to convey an oxygen-containing fluid stream;
• and
• an oxygen-porous membrane disposed between said first and second flow paths;
• flowing said reactant stream along said first flow path such that at least said carbon monoxide contained therein contacts said preferential oxidation catalyst;
• and
• variably flowing oxygen to said first flow path in order to promote a preferential oxidation reaction between said oxygen and said carbon monoxide that is in contact with said preferential oxidation catalyst, said variably flowing of said oxygen comprising:
• continuously flowing oxygen contained in said second flow path along at least a portion of said length of said first flow path such that said continuously flowing oxygen passes across said membrane and to said carbon monoxide that is in contact with said preferential oxidation catalyst;
• and
• discretely flowing oxygen into an upstream portion of said first flow path in such quantity that catalytic reaction with said carbon monoxide that is in contact with said preferential oxidation catalyst occurs while inhibiting in said first flow path both the consumption of hydrogen in said reactant stream and the formation of a reverse water gas shift reaction in said reactant stream, a combination of said continuously flowing and said discretely flowing configured to avoid an even distribution of oxygen throughout said first flow path.