| 摘要 |
A hydrocarbon capable of undergoing skeletal rearrangement and/or double bond shift, which may be cyclic or acyclic, is isomerized in the presence of an anhydrous neutral metal sulphate carried on an inactive support. Preferred metal sulphates are of general formula X2(SO4)n; X may particularly be Mg, Mn, Ni. Examples also relate to the use of Zn, Th, V, Cr sulphates. The sulphates, which may be derived by thermal dehydration of the hydrated salt, are preferably supported on a substance of surface area greater than 100 sq. m./gm., e.g. silica gel, and the total catalyst may contain 5-40% by weight of the metal sulphate. Isomerization may be effected in the vapour phase using a hydrocarbon L.H.S.V. in the range 0.1 to 10 vol./vol., and an inert gaseous diluent, e.g. N2, in the ratio of hydrocarbon to diluent of between 0.1 and 10 to 1. Suitable feedstocks include 3,3-dimethyl-butene-1 and 4-methylpentene-1; the latter undergoes isomerization, preferably at 100-200 DEG C. using magnesium sulphate, to give a substantial yield of 2-methylpentene-2 with cis- and trans-4-methylpentene-2 as predominant side-product. |
