1833. ----------------. [KOCH, H., AND RICHTER, H.] [Isomerization of Butene.] Oel u. Kohle, vol. 40, 1944, pp. 231-241; British Abs., 1948, B, II, p. 285; Chem. Abs., vol. 44, 1950, p. 5307.

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Literature Abstracts

1833. ---------------. [KOCH, H., AND RICHTER, H.] [Isomerization of Butene.] Oel u. Kohle, vol. 40, 1944, pp. 231-241; British Abs., 1948, B, II, p. 285; Chem. Abs., vol. 44, 1950, p. 5307.

When a n-C₄H₈ is isomerized at 190° on a Fischer-Tropsch catalyst, a shifting of the ethylenic linking and cis-trans-conversion takes place, yielding an equilibrium mixture that accords with that calculated by Frost from free energies of the isomers. At higher temperature and pressure, slight cracking occurs and a red polymer is formed as a byproduct. Active C catalyzes the shift of the ethylenic linking at 325°, the main reaction being a redistribution of H₂, with formation of C₄H₁₀ and higher unsaturated hydrocarbons. Al₂O₃ catalyzes this shift at 190°, but at 400° iso-C₄H₈ is formed accompanied by cracking, which gives C₃H₆ and polymerization leading to C₅H₁₀ as main product. In presence of H₂ phosphates of Cd as catalyst formation of iso-C₄H₈ occurs at a lower temperature and is accompanied by polymerization; at a higher temperature polymerization is reduced, but the catalyst soon loses its activity. If in the Fischer-Tropsch synthesis, C₄H₈-isomers are added to the reactant gases, besides hydrogenation, shift of the ethylenic linking occurs, by which the composition of the residual C₄H₈ approaches the equilibrium for n-C₄H₈; C₅ hydrocarbons are not produced from C₄H₈ in this reaction.