NOVELTY - Apparatus (100) for conducting production of synthesis gas from a hydrocarbon feedstock, comprises outer shell (101); vertically disposed catalyst tubes (102); a catalyst tube supporting structure (104); means (105) for heating the catalyst tubes (102); inlet conduct (106) for introduction of the heat exchanging medium (10); outlet conduct (107) for withdrawal of heat exchanging medium; inlet conduct (108) for introduction of hydrocarbon feedstock (11); outlet conduct (109) for withdrawal of synthesis gas (12); and inlet conduct (110) for the introduction of cooling medium (13).    USE - The apparatus is useful for production of synthesis gas from hydrocarbon feedstock or for production of synthesis gas from filtered gas from gasifier to convert tar, ammonia and methane (claimed).    DETAILED DESCRIPTION - Apparatus (100) for conducting production of synthesis gas from a hydrocarbon feedstock, comprises outer shell (101); vertically disposed catalyst tubes (102) containing reforming catalyst (103) which fill a portion of the catalyst tubes (102); a catalyst tube supporting structure (104); means (105) for heating the catalyst tubes (102) indirectly with a heat exchanging medium (10); inlet conduct (106) for the introduction of the heat exchanging medium (10); outlet conduct (107) for the withdrawal of the heat exchanging medium after having delivered heat to the catalyst (103); inlet conduct (108) for introduction of hydrocarbon feedstock (11) and which is in fluid communication with catalyst (103) arranged within the catalyst tubes (102); outlet conduct (109) for the withdrawal of synthesis gas (12) after having passed through the catalyst tubes (102); and inlet conduct (110) for the introduction of cooling medium (13) where the cooling medium (13) is in heat conducting relationship with the catalyst tube structure (104) and in fluid communication with the catalyst (103) arranged within the catalyst tubes (102). An INDEPENDENT CLAIM is a process for production of synthesis gas from hydrocarbon feedstock in the apparatus comprising passing the hydrocarbon feedstock through a reforming stage in a heat exchange reformer which is provided with catalyst tubes containing reforming catalyst in indirect heat conducting relationship with a heating medium, and withdrawing from the heat exchange reformer a synthesis gas in the form of a reformed hydrocarbon stream, where the process further comprises adding a cooling medium to the heat exchange reformer.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of apparatus for conducting production of synthesis gas from hydrocarbon feedstock.    Apparatus (100)    Outer shell (101)    Catalyst tubes (102)    Reforming catalyst (103)    Catalyst tube supporting structure (104)