Steam reforming

A process for steam reforming a hydrocarbon feedstock containing 0.1 to 25% by volume of nitrogen gas (N2), comprising passing a mixture of the hydrocarbon feedstock and steam through a catalyst bed consisting of two, three, or more layers of nickel steam reforming catalysts disposed within a plurality of externally heated tubes in a tubular steam reformer, wherein each tube has an inlet to which the mixture of hydrocarbon and steam is fed, an outlet from which a reformed gas containing hydrogen, carbon monoxide, carbon dioxide, steam, ammonia and methane is recovered, the layer of nickel steam reforming catalyst adjacent the inlet of the tubes is a particulate non-eggshell nickel steam reforming catalyst comprising 10-30% nickel, expressed as NiO, and the nickel steam reforming catalyst at the outlet of the tubes is a particulate eggshell steam reforming catalyst comprising 2.5 to 9.5% by weight nickel, expressed as NiO, wherein the particulate eggshell steam reforming catalyst comprises 5-95% of the volume of the catalyst bed, wherein the nickel is provided at the surface of the particulate eggshell steam reforming catalyst in a layer having a thickness of 100 to 1000 μm, and wherein the methane content of the reformed gas is less than 15% by volume on a dry gas basis and the ammonia content of the reformed gas is below 200 ppmv on a dry gas basis.