Reactor and process for carrying out endothermic or exothermic catalytic reaction

1. A heat exchange reactor for carrying out endothermic or exothermic reactions comprising:

a housing defining an external reactor wall ( 1 ),

a plurality of heat transfer tubes ( 2 ) arranged within said housing for the supply or removal of heat in catalyst beds ( 3 , 3 ′) disposed at least outside said heat transfer tubes ( 2 ) and built-in elements ( 4 ) which are elongated members running in parallel with respect to the heat transfer tubes and are disposed in the outer periphery of said catalyst bed ( 3 ), wherein said built-in elements are peripheral heat transfer tubes in which a heat exchanging medium passes through and said heat exchanging medium is a fluid gas running co-currently or counter-currently to the process gas stream passing through said catalyst bed, wherein the built-in elements ( 4 ) are positioned in direct contact with the external reactor wall ( 1 ).

2. A heat exchange reactor for carrying out endothermic or exothermic reactions comprising:

a housing defining an external reactor wall ( 1 ),

a plurality of heat transfer tubes ( 2 ) arranged within said housing for the supply or removal of heat in catalyst beds ( 3 , 3 ′) disposed at least outside said heat transfer tubes ( 2 ) and built-in elements ( 4 ) which are elongated members running in parallel with respect to the heat transfer tubes and are disposed in the outer periphery of said catalyst bed ( 3 ), wherein said built-in elements are peripheral heat transfer tubes in which a heat exchanging medium passes through and said heat exchanging medium is a fluid gas running co-currently or counter-currently to the process gas stream passing through said catalyst bed, wherein the built-in elements ( 4 ) have a substantially triangular or semi-circular cross-section.

3. A process for the steam reforming of hydrocarbon feedstocks comprising:

(a) forming a combined gas ( 5 ) in a heat exchange reactor comprising:

a housing defining an external reactor wall ( 1 ), and

a plurality of heat transfer tubes ( 2 ) arranged within said housing for the supply or removal of heat in catalyst beds ( 3 , 3 ′) disposed at least outside ( 3 ) said heat transfer tubes ( 2 ) and built-in elements ( 4 ) which are elongated members running in parallel with respect to the heat transfer tubes and are disposed in the outer periphery of said catalyst bed ( 3 ), wherein said built-in elements are peripheral heat transfer tubes in which a heat exchanging medium passes through and said heat exchanging medium is a fluid gas running co-currently or counter-currently to the process gas stream passing through said catalyst bed;

by combining hot effluent gas from an autothermal reformer with converted process gas ( 6 ) leaving catalyst beds ( 3 , 3 ′) disposed at least outside the heat transfer tubes ( 2 ) of said reactor,

(b) passing said combined gas ( 5 ) through the annular space of said heat transfer tubes for indirect heating of said catalyst beds ( 3 , 3 ′), and

(c) removing said combined gas ( 5 ) from the heat exchange reactor as a hydrogen-rich synthesis gas stream, wherein the peripheral heat transfer tubes ( 4 ) are positioned near or at the external reactor wall ( 1 ) and the combined gas ( 5 ) of step (a) is passed through said peripheral heat transfer tubes ( 4 ) positioned in parallel with the heat transfer tubes ( 2 ).

4. A process according to claim 3 , wherein heat transfer tubes ( 2 ) are double tubes and the combined gas ( 5 ) is passed through the annular space of said double-tubes.