Catalytic steam reforming of hydrocarbons

Claim 1

An improved process for the catalytic stream reforming of fluid hydrocarbons comprising: (a) catalytically reacting a major portion of a fluid hydrocarbon feed stream with steam in catalyst-containing reformer tubes positioned within a first primary reforming zone maintained at an elevated temperature by radiant heat transfer and/or by contact with combustion gases, the hot reformer tube effluent comprising a first reformed gas mixture which is passed directly to the hot discharge end of the reformer tubes in the second primary reforming zone; (b) catalytically reacting the remaining portion of said hydrocarbon feed stream with steam at an elevated temperature in a second primary reforming zone having catalyst-containing reformer tubes positioned therein, the hot effluent from said tubes comprising a second reformed gas mixture; (c) combining the first and second reformed gas mixtures at the hot discharge end of the reformer tubes of said second primary reforming zone, thus forming a hot combined reformer gas stream within said second primary reforming zone at the hot discharge end of the reformer tubes therein; (d) passing the hot combined reformer gas stream countercurrently on the shell side of said second primary reaction zone, thereby supplying heat to maintain said second primary reforming zone at an elevated temperature; and (e) withdrawing the thus-partially cooled combined reformer effluent stream, comprising a combination of said first and second reformed gas mixtures, from said second primary reaction zone, whereby the desired overall steam reforming is accomplished at a substantial reduction in hydrocarbon fuel consumption.