N-alkene(s) mixed with hydrogen isomerised to I-alkene(s) - by halide-doped alumina or silica catalyst continuously regenerated

摘要

i-Alkenes are prepd. catalytically from n-alkenes in presence of H2 at a temp. of 400-600 deg.C. The catalyst is prepd. by copptn. of hydrated Al2O3 and/or SiO2 with NH4 salts, calcining (with loss of the latter) to give activated Al2O3 and/or SiO2, and then doping with a halide of Periodic Gps. IIIa-Va, IIb-VIIb or VIII, and/or of H. After activity loss, the catalyst is regenerated by an O2-contg. gas and a halohydrocarbon at a temp. of 400-800 deg.C.; by using a mobile bed, e.g. a fluidised bed, a purged catalyst stream may be regenerated continuously or discontinuously. Used for treating e.g. 4-8C, pref. 4-5C, esp. 4C n-alkenes and mixtures contg. them, e.g. the 4C prod. stream from steam cracking after removal of butadiene and i-butene. Yields and conversions are high. Catalyst regeneration does not require process interruption.