A process is proposed for producing synthesis gas with reduced steam export by catalytic steam reforming of a hydrocarbonaceous feed gas with steam in a multitude of reformer tubes in a burner-heated reformer furnace to form a steam reforming flue gas. This process includes a configuration of the reformer tubes as reformer tubes with internal heat exchange and the use of a structured catalyst. For amounts of export steam between 0 and 0.8 kg of export steam per m.sub.N.sup.3 of hydrogen produced, these features interact synergistically when particular steam reforming conditions are selected.

An expandable center arrangement for a reactor is disclosed. The arrangement comprises an expansion tube; a center support inside the expansion tube and three or more spring elements. The spring elements are fastened to the center support and arc out to the expansion tube. A reactor is also disclosed.

An expandable center arrangement for a reactor is disclosed. The arrangement comprises an expansion tube; a center support inside the expansion tube and three or more spring elements. The spring elements are fastened to the center support and arc out to the expansion tube. A reactor is also disclosed.

A heat conducting insert for a reactor includes an elongated center portion, a cross member extending outwardly from the center portion and an outer portion extending laterally from a distal end of the cross member. A reactor includes a shell and an insert in the shell. The insert includes an elongated center portion, a cross member extending outwardly from the center portion, and an outer portion extending laterally from a distal end of the cross member.

An apparatus includes an inlet, an outlet, and a sheet disposed proximate a heat transfer surface, wherein the sheet is oriented in a sheet plane that is displaced from a plane of the heat transfer surface by an angle of at least 10 degrees. The apparatus also includes a plurality of tabs attached to the sheet, the tabs lying in respective tab planes, wherein the tab planes and the sheet plane intersect forming respective intersections. The intersections of the tab planes and the sheet plane are substantially parallel. The intersections of the tab planes and the sheet plane are at an angle of less than 88 to the heat transfer surface, and the plurality of tabs collectively form channels directing a fluid passing from the inlet to the outlet to impinge the heat transfer surface.

A chemical flow reactor comprising: a housing having an inlet and an outlet; at least one heat exchange pipe extending through the interior of the housing; a space defined between the interior surface of the housing and the outer surface of Gas Flow the at least one pipe, said space being in fluid communication with the inlet and the outlet; and a plurality of plates stacked within said space forming a stacked plate assembly between the inlet and the outlet, each plate comprising at least one hole through which the at least one pipe extends such that the at least one pipe extends through the stacked plate assembly. An active chemical, such as a catalyst, is disposed on each plate.