GB1006745A - Process for forming a hydrogen rich synthesis gas - Google Patents

Abstract

<PICT:1006745/C4-C5/1> Hydrogen-rich synthesis gas containing principally H2, CO, CO2 and steam is produced by continuous steam reforming of naphtha wherein naphtha preheated to a temperature below 1000 DEG F. (540 DEG C.), preferably 400-800 DEG F., is mixed with steam preheated to at least 1000 DEG F., preferably 1500-1800 DEG F., at a steam-carbon ratio between 2 and 6 : 1, preferably 5-6 : 1, to form a mixture at least 1000 DEG F., preferably 1400-1700 DEG F., the mixture is allowed to react for up to 1 second, preferably 0.05-0.33 second, and the partially reacted mixture is passed at a linear velocity of at least 5 ft./sec., preferably 10-30 ft./sec., into an externally heated reforming catalyst of supported nickel or cobalt maintained at a temperature of at least 1400 DEG F. (760 DEG C.). A pressure of 1-22 atmos. may be used. Preferably the partially reacted gas mixture is divided into a plurality of separate streams and passed downwardly through a vertically disposed bed of catalyst so that local depression of temperature is avoided and the deposition of free carbon and formation of lower hydrocarbons does not occur. In the Figure, vaporized liquid naphtha, 3, steam 4, and optionally CO2 5, are mixed, passed through initial reaction zone 8 in less than 1 second, and passed into catalytic reformer 10; 10 comprises catalyst beds 12 in reformer tubes 11 which are heated by combustion of fluid hydrocarbon 13 in air 14. The reformed gas product is withdrawn at 16 and has a typical analysis 72.4% H2, 14.7% CO2, 11.5% CO, 1.0% methane. Pure hydrogen may be obtained by oxidation of CO and removal of CO2 with hot K2CO3. Examples describe the production of gas of 70% H2 content and to the formation of methanol synthesis gas from an initial mixture containing naphtha, steam and CO2. The naphtha feed had an initial boiling point of 130 DEG F., and end-pt. of 380 DEG F., specific gravity at 60 DEG F. of 0.725 and a sulphur content of 4 p.p.m.ALSO:<PICT:1006745/C1/1> Hydrogen-rich synthesis gas containing principally H2, CO, CO2 and steam is produced by continuous steam reforming of naphtha wherein naphtha preheated to a temperature below 1000 DEG F. (540 DEG C.) is mixed with steam pre-heated to at least 1000 DEG F., at a steam-carbon ratio between 2 : 1 and 6 : 1 to form a mixture at 1000 DEG F. at least, the mixture is allowed to react for up to 1 second and is then passed at a linear velocity of at least 5 feet/second into an externally heated reforming catalyst of supported nickel or cobalt maintained at 1400 DEG F. (760 DEG C.) at least; 1-22 atmospheres pressure may be employed. In the Figure vaporized liquid naphtha 3, steam 4, and optionally CO2 5, are mixed and passed consecutively into initial reaction zone 8 and catalytic reformer 10, the latter comprising catalyst beds 12 in reformer tubes 11, heated by combustion of fluid hydrocarbon 13 in air 14. The reformed gas product typically analyses 72.4% H2, 14.7% CO2, 11.5% CO, 1.0% CH4. Pure hydrogen is obtained by oxidizing CO to CO2 and absorbing the latter in hot K2CO3.