(DE19727588-C1)      A gaseous mixture high in H2 and low in carbon monoxide (CO), is generated in an apparatus from a water/fuel mixture by catalytic steam reforming and partial oxidation of the product gas. The CO level is reduced by its selective catalytic oxidation in a gas purification stage.    During an initial phase, oxygen is added to the fuel material and the direction of flow is reversed so that the gas passes first through the purification stage and then through the gas generation apparatus.    USE -   To produce hydrogen suitable for use in a vehicle fuel cell.    ADVANTAGE -   The final gas is rich in H2 and low in CO, therefore having better cold-start properties.    (EP887306-B1)      A gaseous mixture high in H2 and low in carbon monoxide (CO), is generated in an apparatus from a water/fuel mixture by catalytic steam reforming and partial oxidation of the product gas. The CO level is reduced by its selective catalytic oxidation in a gas purification stage.    During an initial phase, oxygen is added to the fuel material and the direction of flow is reversed so that the gas passes first through the purification stage and then through the gas generation apparatus.    USE -   To produce hydrogen suitable for use in a vehicle fuel cell.    ADVANTAGE -   The final gas is rich in H2 and low in CO, therefore having better cold-start properties.    (US6241792-B1)      A gaseous mixture high in H2 and low in carbon monoxide (CO), is generated in an apparatus from a water/fuel mixture by catalytic steam reforming and partial oxidation of the product gas. The CO level is reduced by its selective catalytic oxidation in a gas purification stage.    During an initial phase, oxygen is added to the fuel material and the direction of flow is reversed so that the gas passes first through the purification stage and then through the gas generation apparatus.    USE -   To produce hydrogen suitable for use in a vehicle fuel cell.    ADVANTAGE -   The final gas is rich in H2 and low in CO, therefore having better cold-start properties.    (US2001005500-A1)      A gaseous mixture high in H2 and low in carbon monoxide (CO), is generated in an apparatus from a water/fuel mixture by catalytic steam reforming and partial oxidation of the product gas. The CO level is reduced by its selective catalytic oxidation in a gas purification stage.    During an initial phase, oxygen is added to the fuel material and the direction of flow is reversed so that the gas passes first through the purification stage and then through the gas generation apparatus.    USE -   To produce hydrogen suitable for use in a vehicle fuel cell.    ADVANTAGE -   The final gas is rich in H2 and low in CO, therefore having better cold-start properties.