METHOD OF OBTAINING 2-METHYL-2-BUTENE FROM ISOPENTANE AND METHOD OF OBTAINING ISOPRENE FROM ISOPENTANE Russian patent published in 2008 - IPC C07C5/13 C07C11/10 C07C11/18 C07C1/24 

FIELD: chemistry.

SUBSTANCE: invention pertains to the method of obtaining 2-methyl-2-butene from isopentane, including gas phase dehydrogenation of isopentane in the dehydrogenation zone, extraction of the C₅-fraction from contact gas, mainly consisting of isopentane, tert pentanes, isoprene impurities and other hydrocarbons and obtaining a stream from it, mainly consisting of 2-methyl-2-butene, with use of a liquid phase isomerisation catalyst in a C₅-fraction 2-methyl-1-butene in 2-methyl-2-butene and distillation. The method is characterised by that, the above mentioned C₅-fraction, possibly containing extra piperylene and 2-pentene, directly or after distillation from the larger part of 2-methyl-2-butene, undergoes liquid phase hydroisomerisation in the presence of a solid catalyst, containing group VIII metal(s), capable of simultaneous catalysing hydrogenation of pentadienes, isoprene and possibly, piperylenes, and positional isomerisation of tert pentenes, preferably with subsequent additional isomerisation of 2-methyl-1-butene in 2-methyl-2-butene on a sulfocationite catalyst, and distillation with output of a distillate stream of mainly isopentane, containing not more than 1.0% mass, preferably not more than 0.2% mass of pentadiene(s), which are mainly recirculated in the hydrogenation zone, and output from the lower part of the recirculation stream of mainly 2-methyl-2-butene with impurities of n.pentane and possibly 2-pentenes. The invention also pertains to the method of obtaining isoprene from isopentane, which involves reaction of 2-methyl-2-butene, obtained from gas phase dehydrogenation of isopentane, with hydroperoxide with further conversion of the oxide or products of hydroxylation in isoprene.

EFFECT: obtaining 2-methyl-2-butene and isoprene from isopentane.

13 cl, 8 ex, 2 tbl, 3 dwg