PROCESS FOR THE PREPARATION OF I-ALKENES, CATALYST USEFUL THEREFOR AND PROCESS FOR THE PRODUCTION THEREOF

摘要

n-Alkenes can be converted catalytically into isoalkenes, when a mixture containing at least one n-alkene and hydrogen is brought into contact at a temperature of 400 DEG to 600 DEG C. and a residence time of 0.2 to 20 seconds with an Al2O3 or SiO2 catalyst which is specifically activated and is promoted with halogen compounds of elements of the third to fifth main groups and second to eighth sub-groups of the periodic system and/or hydrohalic acids. The specific activation comprises calcining, before the promotion process, an aluminum hydroxide or aluminum oxide hydrate or a silica gel having a content of volatile ammonium salts to give Al2O3 or SiO2, with expulsion of these volatile ammonium salts. For the conversion of the n-alkenes, the catalyst can be employed in a fixed or a mobilized catalyst bed. In cases where the catalyst is used in a mobilized catalyst bed it can be passed, by continuous or discontinuous removal of a portion of it, to a separate regeneration process and following regeneration can be reintroduced into the mobilized catalyst bed.