Patent ID: 6296679
Filing Date: 2001-10-02
Classification: B01J,C01B,Y02P

Abstract:
A method of hydrocarbon steam reforming for producing a reformed gas by a steam reforming reaction of a mixed gas of hydrocarbon and steam, which comprises: reforming the mixed gas of hydrocarbon and steam using an arrangement comprising an external combustion reforming furnace and an internal combustion reactor reformer, the reforming furnace being provided with reforming tubes filled with catalyst and heating means for heating the reforming tubes, the heating means including burners for heating the reforming tubes and regenerators for preheating a combustion air flow fed to the burners;wherein the arrangement further comprises a first flow passage provided with a first regenerator and a second flow passage provided with a second regenerator;wherein combustion exhaust gas from the reforming furnace passes through the second flow passage provided with the second regenerator while a first burner is in firing operation, thereby heating the second regenerator for preheating combustion air flow to a second burner, whereas said combustion exhaust gas passes through the first flow passage provided with the first regenerator while the second burner is in firing operation, thereby heating the first regenerator for preheating combustion air flow to the first burner, said combustion exhaust gas being controlled to be switched in a time interval no greater than 120 seconds so as to alternately flow through the first and second passages;wherein a part of said combustion exhaust gas, which is a ratio of the part of said combustion exhaust gas relative to a total amount of said combustion exhaust gas, is introduced from an internal area of the reforming furnace to a heat-exchanger so that at least one component selected from the group consisting of (a) hydrocarbon feedstock, (b) said mixed gas of hydrocarbon and steam, (c) air and/or oxygen, and (d) fuel gas for the reforming furnace is heated by heat-exchange with said part of the combustion exhaust gas;wherein said ratio of the part of the combustion exhaust gas is predetermined to be a ratio by weight in the range from 10% to 30%.