Patent GB-1044273-A (GB)
Title: Process for the production of hydrogen
IPC: C01B3/28
Filed: 1964-01-21
Abstract: In the production of hydrogen by the decomposition of a hydrocarbon charge stream in the gaseous phase and in the presence of subdivided catalyst particles, the hydrocarbon stream enters the lower end of a vertically elongated reaction zone and the heated and stripped catalyst particles, entering the upper end of the reaction zone, are passed at decomposition conditions downwardly and countercurrently to the hydrocarbon stream to produce a hydrogen-containing product stream and carbon-containing particles.  The latter are withdrawn from the reaction zone and passed to the lower end of a regeneration zone, where they are in contact with a regeneration stream containing free oxygen in a controlled quantity sufficient to burn and remove at least part of the carbon content of the particles.  After discharge from the upper end of the regeneration zone, the heated particles are separated from the flue gas at an elevation above the reaction zone and passed downwardly through a stripping zone in countercurrent to a stripping stream comprising at least part of the hydrogen-containing stream rising from the reaction zone, the stripped particles being subsequently passed downwardly from the lower end of the stripping zone to the upper end of the interconnecting reaction zone. <PICT:1044273/C1/1> A hydrogen-containing gas stream is withdrawn from the upper end of the reaction zone as product.  Preferably, a normally gaseous hydrocarbon is passed into the lower end of a multiple stage reaction zone, the catalyst particles passing through the reaction zone in countercurrent to the charge stream are subjected to a series of redistributions, and the regeneration stream contains sufficient free oxygen to provide a carbon monoxide-rich stream overhead from the regeneration zone and to impart to the regenerated particles at least part of the heat consumed by the decomposition reaction.  Catalyst particles passing through the stripping zone in countercurrent to the stripping stream may also be subjected to a series of redistributions. The hydrocarbon stream may be methane; materials suitable for the catalyst are listed in the Specification.  Fig. 1 illustrates apparatus for the above process, in which reaction zone 1 is openly connected with an enlarged section 5 providing a disengaging zone 6, in which is internal stripping zone 7.  The hydrocarbon stream enters the reaction zone via line 2 and valve 3 and passes in countercurrent to heated and stripped catalyst particles entering from the stripping zone. Carbon-containing catalyst particles are withdrawn from the reaction zone via outlet 16, valve 17 and line 18 and pass to regeneration zone 19, where they are in continuous upward-flowing contact with a regeneration stream entering via line 20 and valve 21.  The particles and flue gas pass via line 22 to separator 23, the flue gas being discharged via line 24, while the particles pass via line 9 to the upper end of the stripping zone, in which they pass in countercurrent to a stripping gas stream, which then is passed through disengaging section 10 and discharged via line 11.  The major portion of the hydrogen-rich product stream passes through the disengaging zone and via line 12 to separator 13, from which a particle-free hydrogen stream is discharged as product via line 14, the catalyst particles being returned via line 15 to the reaction zone.  Both the reaction and stripping zones have vertically spaced redistribution plates 4 and 8, respectively, to effect multiple stage countercurrent contact between descending catalyst particles and rising gaseous stream.  In a modification, Fig. 2 (not shown), the stripping zone is external to the upper portion of the reaction zone.