Furnace and steam reforming process

摘要

A steam reforming furnace (F) has a plurality of substantially vertical reformer tubes (T). Each reformer tube (T) has a feed inlet (P) at its lower end, an outlet at its upper end, and a catalyst containment zone disposed intermediate its upper and lower ends and contains a charge of a particulate steam reforming catalyst (C) which is insufficient to fill completely the catalyst containment zone. An upper retainer means (3) is mounted at the upper end of the catalyst containment zone and is permeable to gas or vapour but retains particles of the catalyst (C) in the catalyst containment zone. A follower means (4; 24) is movably mounted in the catalyst containment zone beneath the charge catalyst (C) for movement upwardly from a lower end of the containment zone upon upward flow of gas through the catalyst containment zone at a rate beyond a threshold rate. A reactant mixture comprising the hydrocarbon feedstock and steam flows upwardly through each reformer tube (T) at a flow rate which is sufficient to cause the catalyst (C) in each reformer tube (T) to rise up and form a cushion of catalyst (C) against the underside of the upper retainer means (3) in its reformer tube (T) and which is in excess of the threshold rate so as to cause the follower means (4; 24) in the reformer tube (T) to move upwardly until it abuts against the underside of the cushion of catalyst (C) in its reformer tube (T). The reformer tubes (T) are heated externally by means of the steam reformer furnace (F) so as to maintain steam reforming conditions in each of the plurality of reformer tubes (T) and convert the hydrocarbon feedstock by reaction with steam to form a reformed gas mixture comprising carbon oxides and hydrogen.