| 摘要 |
1329162 Catalytic reactor VARTA AG 19 April 1971 [13 April 1970] 26780/71 Heading B1F [Also in Division C1] A catalyst for the decomposition of ammonia into hydrogen and nitrogen consists of a finely divided alloy of nickel and iron and/or cobalt, the iron and/or cobalt being 5-80% preferably 8-20%. The alloy is derived in the Raney manner, i.e. an alloy of iron, nickel and inactive aluminium is leached of the latter to give a porous powder structure which is then compacted and hot pressed into a desired shape. A surface layer of the powder may be oxidised so as to be non-pyrophoric. Alternatively, the alloy may be aggregated with another metallic powder, e.g. nickel carbonyl. which acts as a supporting skeleton to aid heat transfer- and a removable pore former, e.g. NaCl or Na 2 CO 3 may be added, the mixture finally being pressed into a desired shape and sintered. The catalyst body so produced may be a flat disc or plate optionally having a central opening, which is placed across a metal tube through which hot ammonia is directed, a series of discs and tubes may be used. If the disc has a central opening then its upper and lower surfaces are made gas tight with an asbestos plate and a copper ring with a circumferential opening is fitted around its edge. Ammonia fed into the central hole then percolates radially through the catalyst, heated to 500-720‹C preferably 600-700‹C, the product gases being collected in the copper ring. The apparatus may comprise many catalyst tubes, the ammonia being initially preheated either by butane burners from below or by heat generated by burning a portion of the product gas. |
