METHOD FOR OBTAINING ISOPROPYLBENZENE BY ALKYLATION OF BENZENE WITH PROPYLENE Russian patent published in 2022 - IPC C07C15/85 C07C2/66 B01J23/02 B01J29/70 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing isopropylbenzene by alkylation of benzene with propylene. The method provides for alkylation in a multi-band contact alkylator with adiabatic layers of an alkylation catalyst located on each shelf of the alkylator, with the introduction of recycled benzene at the inlet of the alkylator, the reaction mass of alkylation and part of the separated propylene stream at the inlet and between the shelves of the alkylator, rectification of the resulting alkylation mass and extraction of isopropylbenzene. The method is characterized by the fact that the following is carred out: a) the supply of a mixture of purified benzene and heated recycled benzene to the alkylator, propylene is divided into four streams; the first of which is mixed with a mixture of purified benzene and heated recycled benzene, the resulting alkylation reaction mass is fed to the first alkylator shelf filled with an alkylation catalyst containing, wt. %: calcium oxide 0.4-1.2, zeolite Hβ with a molar ratio SiO₂/Al₂O₃ = 25 49.4-49.8, binder γ-AlO₃, which is a mixture of, wt. %: 25 aluminum hydroxide grade Pural SB and 25 aluminum hydroxide Disperal HP 14 the rest, with the production of an alkylation reaction mass stream containing benzene alkylation products with propylene and unreacted benzene; b) the second, third and fourth propylene streams are mixed in a static mixer with an alkylation reaction mass stream cooled in an external remote refrigerator with parallel steam generation, leaving the previous alkylator shelf containing benzene alkylation products with propylene and unreacted benzene, after which the resulting mixture is fed to the next shelf of the alkylator; c) the alkylation reaction mass stream containing benzene alkylation products with propylene and unreacted benzene at the outlet from the last shelf of the alkylator is divided into two streams: the first stream is directed to rectification, including the separation of the formed polyalkylbenzenes and the separation of isopropylbenzene, and the second stream is divided into an uncooled recycle reaction mass stream and a cooled recycle reaction mass stream, then the uncooled recycle reaction mass stream is fed to the alkylator inlet, and between the shelves of the alkylator, a cooled recycle flow of the reaction mass is fed.

EFFECT: invention provides an increase in the catalytic activity of the catalyst, which makes it possible to obtain a target product with a propylene conversion above 90% and a yield of more than 85 wt. %.

1 cl, 1 dwg, 1 tbl, 7 ex