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Return to Abstracts of Patents Return to Abstracts of Patents 1250-1499 Patent Abstracts1358. ------. [I. G. FARBENINDUSTRIE, A. G.] Olefins. British Patent 507,567, June 13, 1939. Chem. Abs., vol. 34, 1940, p. 452. Gaseous olefins are obtained from the products of the catalytic hydrogenation of CO, the constituents of which contain more than 1 C atom and may or may not contain O, by leading them at elevated temperature with H2 over a hydrogenation catalyst and cracking and/or dehydrogenating the resulting hydrocarbons. The initial products may be led with H2 at 180º-200º and ordinary or elevated pressure over metals of groups 6-8 or their compounds; for example, Ni on carriers. The subsequent cracking is effected in known manner: that is, at >700º, with use of apparatus that inhibits C deposition, such as comprising coatings of Si or Ri or Cr steels, as described in British Patents 403,647 and 469,101. The products may be separated; liquid products are returned to the hydrogenation or constituents boiling at 80º-120º, mainly aromatic hydrocarbons, are removed. Gaseous products may be treated to remove acetylenic compounds, olefins then being separated with ammoniacal cuprous salts. C2H4 may be separated by pressure distillation and the higher olefins hydrogenated, as described in British Patent 506,832 (abs. 1234). and wholly or in part subjected to cracking or dehydrogenation. In example and oil obtained from CO and H2 is hydrogenated at 200º and 180 atm. with use of a Ni-Al catalyst and led with cracking gas through a packed tube of Cr steel at 750º, a gas containing C2H4, 35%: higher olefins, 20%: H2, 10%; CH4, 30%: CH4 homologs, 5% and an oil containing C6H6 hydrocarbons being obtained. |