Manufacture of hydrogen

摘要

Hydrogen free from nitrogen, oxides of carbon, and oxygen is obtained by treating a bed of a heavy metal oxide with fumes resulting from catalyst regeneration in a catalyst exacting plant at elevated temperature in a reducing zone, and removing the reduced metal oxide to another zone where it is treated in a fluidized bed with steam at elevated temperature to form hydrogen and the metal oxide. In a preferred embodiment, an iron ore such as haematite is contained in the reducing zone 1 and air and refinery tail gas are admitted through 3, to reduce the ore, which then passes through 9 into zone 13, into which steam is admitted via 15, which reacts to reform the original ore and high purity hydrogen. The hydrogen is removed via cyclone 17. The reoxidized ore is returned to the reducing zone 1 via 5. It is desirable in general that zone 1 is placed higher than zone 13. In this way zone 1 can be operated at only slightly above atmospheric pressure whereas the hydrogen from 13 is generated at pressures equivalent to one stage of compression. The process is carried out between 1200 DEG and 2000 DEG F., preferably between 1500 DEG and 1800 DEG F. It is advantageous to maintain the catalyst regenerator gas in an anhydrous condition, and to remove any carbon dioxide present by washing with an alkaline solution. Specifications 578,323, 586,914, 628,417 and 639,554 are referred to.