System and method for pre-purification of a feed gas stream

A pre-purifier unit for an air-separation unit comprising:

• a vessel having an inlet configured for receiving a stream of compressed feed air and an outlet configured to output a purified stream substantially free of water, carbon dioxide, carbon monoxide and hydrogen;
• a first purification section disposed within the vessel comprising at least one layer of adsorbent configured to remove water and carbon dioxide from the compressed feed air stream and yield a dry feed stream;
• a second purification section disposed within the vessel downstream of the first purification section, the second purification section comprising (i) a first layer of manganese oxide and copper oxide containing catalyst having a copper to manganese ratio in a range of 0.21 to 1.00 and configured to remove at least some of the carbon monoxide and hydrogen from the dry feed stream and produce a first intermediate effluent, (ii) a second layer disposed downstream of the first layer configured to remove water and carbon dioxide from the first intermediate effluent and produce a second intermediate effluent, and (iii) a third layer of manganese oxide and copper oxide containing catalyst layer having a copper to manganese ratio in a range of 0.21 to 1.00 disposed downstream of the second layer and configured to remove hydrogen from the second intermediate effluent to yield an intermediate purified stream substantially free of hydrogen and carbon monoxide;
• and
• a third purification section disposed within the vessel downstream of the second purification section and comprising at least one other layer of adsorbent configured to remove water and carbon dioxide from the intermediate purified stream and yield the purified stream substantially free of water, carbon dioxide, carbon monoxide and hydrogen.