METHOD OF COMBINED PREPARATION OF ISOPRENE AND ISOBUTENE OR ALKENYL BENZENE Russian patent published in 2001 - IPC

FIELD: chemical industry. SUBSTANCE: described is method of combined preparation of isoprene and isobutene or alkenyl benzene having 2-4 carbon atoms in alkyl group, liquid-phase oxidation of isobutene or alkyl benzene to form hydroperoxide, catalytic epoxidation of 2-methyl-2-butene by said hydroperoxide to form oxide 2-methyl-2-butene and alcohol and transformation thereof into isoprene and isobutene, or alkyl benzene respectively, and separation of reaction mixtures are carried out in zones: in this case, 2-methyl-2-butene is prepared by combination of at least processes of dehydrogenation of isopentane, catalytic isomerization when 2-methyl-1- butene is dehydrogenated into 2-methyl-2-butene and, rectification of mixtures resulting from dehydrogenation and isomerization, 2-metyl-1-butene being isomerized directly in dehydrogenation unit into which mixture is recycled after distillation from 2-methyl-2-butene said mixture containing preferably isopentane and 2- methyl-1-butene, or by contacting stream containing 2-methyl-butene and optionally isopentane and 2-methyl-2-butene with acid catalyst at 50-100 C, preferably in the presence of alcohol and/or water follows by subsequent or simultaneous rectification from 2- methyl-2-butene, optionally by subsequent decomposition of alky-tert-pentyl ether at 60-130 C formed in zone of contacting with acid catalyst, recycling isopentane containing stream into dehydrogenation zone, and said alcohol into zone of contacting with acid catalyst, separated steam of 2-methyl-2-butene is reacted with hydroperoxide solution resulting from oxidation of isobutene or alkyl benzene in the presence of epoxidation catalyst to give oxide of 2- methyl-2 butane and tert-butanol or alkylaromatic alcohol which are the converted into desired monomers. EFFECT: simplified process and lower power consumption. 8 cl, 1 dwg, 6 ex