Patent ID: 7105148

Claim:
A method for producing hydrogen gas from a fuel comprising: providing an autothermal primary reactor having a reactant mixture inlet, a product gas outlet, a first reforming reaction zone, and a second reforming reaction zone, wherein said first reforming reaction zone comprises at least one upstream reforming catalyst and is defined in relative close proximity to said reactant mixture inlet; said second reforming reaction zone comprises at least one downstream reforming catalyst and is defined in relative close proximity to said product gas outlet; said first reforming reaction zone is defined substantially exclusively upstream from said second reforming reaction zone, as defined by a fuel flow path extending from said reactant mixture inlet to said reactant mixture outlet; said upstream reforming catalyst is characterized by faster light-off ability than said downstream reforming catalyst, higher operating temperature than said downstream reforming catalyst, and the ability to reform higher concentrations of hydrocarbon fuel than said downstream reforming catalyst, said first and second reaction zones are configured such that a reactant mixture passing from said inlet to said outlet is initially in substantially exclusive contact with said upstream reforming catalyst in said first reforming reaction zone and is subsequently in substantially exclusive contact with said downstream reforming catalyst in said second reforming reaction zone such that said reactant mixture passes through said first reaction zone before passing through said second reaction zone; said upstream catalyst is configured such that substantially all of the upstream catalyst is positioned upstream of substantially all of the downstream catalyst; and passing a reactant mixture of hydrocarbon fuel, oxygen, and steam through said first and second reforming reaction zones to form product gases, one of which comprises hydrogen.