Process for providing a pure hydrogen stream for use with fuel cells

A process for generating hydrogen from a hydrocarbon feedstock for use in a fuel cell system for electric power generation, said process comprising:

• a) passing the hydrocarbon feedstock to a preparation module to produce a conditioned feedstock;
• b) passing the conditioned feedstock at effective pre-reforming conditions to a pre-reforming zone containing a pre-reforming catalyst, said pre-reforming zone being in intimate thermal contact with a first heat exchange zone having a steady-state temperature profile to produce a pre-reforming effluent stream comprising hydrogen, carbon monoxide, carbon dioxide, and water;
• c) passing the pre-reforming effluent stream at effective partial oxidation conditions to a partial oxidation zone containing a partial oxidation catalyst and therein contacting the pre-reforming effluent with a first air stream to produce a partial oxidation effluent stream;
• d) passing the partial oxidation effluent stream at effective reforming conditions to a reforming zone containing a reforming catalyst to produce a reforming effluent stream and withdrawing the reforming effluent stream from the reforming zone at a reforming exit temperature;
• e) passing the reforming effluent stream and a first water stream to a water gas shift reaction zone containing at least one water gas shift catalyst zone, said water gas shift reaction zone being in intimate thermal contact with a second heat transfer zone having a steady-state temperature profile to cool the water gas shift reaction zone to effective water gas shift conditions to produce a hydrogen product stream comprising hydrogen, carbon monoxide, carbon dioxide, and water;
• f) passing the hydrogen product stream to an anode side of a fuel cell zone, said fuel cell having a cathode side on which an oxygen containing stream is contacted to produce the electric power and withdrawing an anode waste gas comprising hydrogen;
• and
• g) returning the anode waste gas to a burner zone wherein the anode waste gas is contacted with a sufficient amount of a second air stream to combust the anode waste gas to produce a flue gas stream at a flue gas temperature and passing the flue gas stream to the first heat exchange zone to heat the pre-reforming zone to the effective pre-reforming conditions.

A process for generating hydrogen from a hydrocarbon feedstock for use in a fuel cell system for electric power generation, said process comprising:

• a) passing the hydrocarbon feedstock to a preparation module to produce a conditioned feedstock;
• b) passing the conditioned feedstock to a pre-reforming zone containing a pre-reforming catalyst, said pre-reforming zone being in intimate thermal contact with a first heat exchange zone having a steady-state temperature profile to heat the pre-reforming zone by convection to produce a pre-reforming effluent stream comprising hydrogen, carbon monoxide, carbon dioxide, and water;
• c) passing the pre-reforming effluent stream at effective partial oxidation conditions to a partial oxidation zone containing a partial oxidation catalyst and therein contacting the pre-reforming effluent with a first air stream at a first air rate to produce a partial oxidation effluent stream;
• d) passing the partial oxidation effluent stream at effective reforming conditions to a reforming zone containing a reforming catalyst to produce a reforming effluent stream and withdrawing the reforming effluent stream from the reforming zone at a reforming exit temperature;
• e) passing the reforming effluent stream and a first water stream to a water gas shift reaction zone containing at least one water gas shift catalyst zone, said water gas shift reaction zone being in intimate thermal contact with a second heat transfer zone having a steady-state temperature profile to cool the water gas shift reaction zone to effective water gas shift conditions to produce a hydrogen product stream comprising hydrogen, carbon monoxide, carbon dioxide, and water;
• f) passing the hydrogen product stream to a pressure swing adsorption zone or a temperature swing adsorption zone to produce a high purity hydrogen stream comprising about 95 to about 99.999 mol-% hydrogen and a separation waste gas stream comprising hydrogen and carbon oxides;
• g) passing the high purity hydrogen product stream to an anode side of a fuel cell zone, said fuel cell having a cathode side on which an oxygen containing stream is contacted to produce the electric power and withdrawing an anode waste gas comprising hydrogen;
• and
• h) returning the anode waste gas and the separation waste gas stream to a burner zone wherein the anode waste gas is contacted with a sufficient amount of a second air stream to combust the anode waste gas and the separation waste gas stream to produce a flue gas stream at a flue gas temperature and passing the flue gas stream to the first heat exchange zone to heat the pre-reforming zone to effective pre-reforming conditions.

A process for producing a high purity hydrogen stream from a hydrocarbon feedstock comprising the following steps:

• a) passing the hydrocarbon feedstock and steam to a convection heated pre-reforming zone, said convection heated pre-reforming zone being maintained at an essentially steady-state temperature profile and at a pre-reforming temperature to produce a pre-reforming effluent;
• b) passing the pre-reforming effluent and a first air stream to a partial oxidation zone in a reaction chamber to produce a partial oxidation effluent;
• c) passing the partial oxidation effluent to a reforming zone wherein the partial oxidation zone and the reforming zone take place in the reaction chamber to produce a reforming effluent stream comprising hydrogen and carbon monoxide;
• d) cooling the reforming effluent stream;
• e) passing the reforming effluent stream to a hydrogen purification zone to produce a pure hydrogen stream and a waste gas stream;
• and
• f) combusting the waste gas stream and a second air stream in a combustion zone which is in intimate thermal contact with the reforming zone to provide a flue gas stream to heat the pre-reforming zone.