STEAM REFORMING CATALYST AND PROCESS
A process for steam reforming in an autothermal or secondary reformer is described, comprising: (i) non-catalytically partially combusting a feed gas comprising a hydrocarbon with an oxygen-containing gas to form a partially combusted gas mixture and (ii) passing the partially combusted gas mixture through a catalyst bed comprising a first layer of a first particulate steam reforming catalyst and a second layer of a second particulate steam reforming catalyst, wherein the partially combusted gas mixture passes through the first layer and then the second layer, the second particulate steam reforming catalyst is an eggshell catalyst comprising nickel coated on a refractory support, and the first layer has a thickness in the range of 20 to 60% of the combined thickness of the first and second layers.
1 . A process for steam reforming in an autothermal or secondary reformer comprising: (i) non-catalytically partially combusting a feed gas comprising a hydrocarbon with an oxygen-containing gas to form a partially combusted gas mixture and (ii) passing the partially combusted gas mixture through a catalyst bed comprising a first layer of a first particulate steam reforming catalyst and a second layer of a second particulate steam reforming catalyst, wherein the partially combusted gas mixture passes through the first layer and then the second layer, the second particulate steam reforming catalyst is an eggshell catalyst comprising nickel coated on a refractory support, and the first layer has a thickness in the range of 20 to 60% of the combined thickness of the first and second layers.
2 . The process according to claim 1 , wherein the feed gas comprises a desulphurized hydrocarbon feedstock or is a pre-reformed or primary-reformed gas stream comprising unreacted hydrocarbon, steam, hydrogen, carbon dioxide and carbon monoxide.
3 . The process according to claim 1 , wherein the oxygen-containing gas is air or oxygen-enriched air.
4 . The process according to claim 1 , wherein the first particulate steam reforming catalyst comprises nickel dispersed throughout a refractory support.
5 . The process according to claim 1 , wherein the first particulate steam reforming catalyst consists of one or more of platinum, palladium, iridium, ruthenium or rhodium dispersed throughout a refractory support or as an eggshell coating on a refractory support.
6 . The process according to claim 4 , wherein the refractory support for the first particulate steam reforming catalyst comprises alumina, calcium aluminate, ceria, titania, zirconia or magnesia or mixtures thereof.
7 . The process according to claim 1 , wherein the refractory support for the second particulate steam reforming catalyst comprises alumina, calcium aluminate or magnesium aluminate.
8 . The process according to claim 1 , wherein the first layer is between 40 and 60% of the combined thickness of the first and second layers.
9 . The process according to claim 1 , wherein a layer of zirconia balls, pellets or tiles is placed on the first layer.
10 . A bed of steam reforming catalyst suitable for use on a secondary or autothermal reformer, wherein the bed comprises a first layer of a first particulate steam reforming catalyst and a second layer of a second particulate steam reforming catalyst in contact with the layer of first particulate steam reforming catalyst, wherein the second particulate steam reforming catalyst is an eggshell catalyst comprising nickel coated on a refractory support, and the first layer has a thickness in the range of 20 to 60% of the combined thickness of the first and second layers.
11 . The bed of steam reforming catalyst according to claim 10 , wherein the first layer of the first particulate steam reforming catalyst comprises nickel dispersed throughout a refractory support.
12 . The bed of steam reforming catalyst according to claim 10 , wherein the first layer of first particulate steam reforming catalyst consists of one or more of platinum, palladium, iridium, ruthenium or rhodium dispersed throughout the refractory support or as an eggshell coating on the refractory support.
13 . The bed of steam reforming catalyst according to claim 11 , wherein the refractory oxide catalyst support for the first particulate steam reforming catalyst comprises alumina, calcium aluminate, ceria, titania, zirconia or magnesia or mixtures thereof.
14 . The bed of steam reforming catalyst according to claim 10 , wherein the refractory oxide catalyst support for the second particulate steam reforming catalyst comprises alumina, calcium aluminate or magnesium aluminate.
15 . The bed of steam reforming catalyst according to claim 10 , wherein the first layer has a thickness between 40 and 60% of the combined thickness of the first and second layers.
16 . The bed of steam reforming catalyst according to claim 10 , wherein an inert layer of zirconia balls, pellets or tiles is placed on the first layer.