Steam or dry reforming of hydrocarbons

An apparatus suitable for carrying out a process for steam or dry reforming of hydrocarbons in a reforming reactor, to form a cooled reformed gas product stream and a further-cooled combustion products stream, wherein the apparatus comprises:

• a housing, the housing containing:
• a first catalytic zone comprising one or more elongate conduits, each containing reforming catalyst, and each having an inlet and an outlet, whereby in use a feedstock comprising one or more hydrocarbons together with steam and/or CO2 can enter a first catalytic zone elongate conduit via its inlet and pass through said first catalytic zone elongate conduit at an elevated temperature, to form a partly reformed process gas, which can then exit via the outlet of said elongate conduit;
• a second catalytic zone comprising one or more elongate conduits, each containing reforming catalyst, and each having an inlet and an outlet, whereby in use partly reformed process gas from the first catalytic zone can enter a second catalytic zone elongate conduit via its inlet and pass through said second catalytic zone elongate conduit at an elevated temperature, so as to form a reformed gas stream, which can then exit via the outlet of said elongate conduit;
• and
• an exothermic combustion region laterally surrounding the second catalytic zone, wherein the exothermic combustion region is associated with a plurality of burner nozzles, a fuel inlet through which fluid fuel can be provided, and a combustion-sustaining medium inlet through which combustion-sustaining medium can be provided, such that in use fluid fuel from the fuel inlet and combustion-sustaining medium from the combustion-sustaining medium inlet can be introduced to each other via said plurality of burner nozzles, and combustion of the fluid fuel with the combustion-sustaining medium can occur in the exothermic combustion region to form a hot combustion products stream, so that in use there can be transfer of heat from the hot combustion products stream to the second catalytic zone via the exothermic combustion region;
• a heat recovery region, being adapted to, in use, receive heat from the reformed gas product stream and from the hot combustion products stream after the hot combustion products stream has provided heat to the second catalytic zone, and to transfer heat to the first catalytic zone;
• a combustion products stream outlet, through which the hot combustion products stream can exit the housing after the hot combustion products stream has lost heat in the heat recovery region;
• and
• a reformed gas stream outlet, through which the reformed gas stream can exit the housing after the reformed gas stream has lost heat in the heat recovery region;
• wherein the apparatus comprises one or more process tube assemblies, each process tube assembly comprising an inner tube and an outer tube in a concentric arrangement, with each inner tube containing a first reforming catalyst portion, with a first reforming catalyst bed, and each outer tube containing a second reforming catalyst portion, with a second reforming catalyst bed, the first reforming catalyst bed and the second reforming catalyst bed arranged in series, whereby the first reforming catalyst portion is part of the first catalytic zone and the second reforming catalyst portion is part of the second catalytic zone, and whereby an internal conduit passes through the second reforming catalyst portion for a purpose of providing partially reformed gas from an exit of the first reforming catalyst bed to an inlet of the second reforming catalyst bed.

A process tube assembly suitable for use in a process for steam or dry reforming of hydrocarbons in a reforming reactor, to form a cooled reformed gas product stream and a further-cooled combustion products stream, the process tube assembly comprising an inner tube and an outer tube in a concentric arrangement,

• wherein the inner tube contains a first reforming catalyst portion, with a first reforming catalyst bed,
• wherein the outer tube contains a second reforming catalyst portion, with a second reforming catalyst bed,
• whereby the first reforming catalyst bed and the second reforming catalyst bed are arranged in series, and
• whereby the inner tube has an exit through which partially reformed gas can leave the inner tube, and whereby an internal conduit, through which partially reformed gas can flow, runs from the exit of the inner tube and passes through the second reforming catalyst portion.