FIELD: chemistry.
SUBSTANCE: present invention pertains to the method of producing alkyl aromatic hydrocarbons. The method is characterised by that, it involves feeding the first stream of hydrocarbons, containing olefin and paraffin, into an isomerasation unit. The isomerisation unit is designed for isomerisation of at least, part of linear olefins in the first stream of hydrocarbons into branched olefins. At least part of unreacted components of the first stream of hydrocarbons and at least, part of obtained branched olefins form the second stream of hydrocarbons. At least part of the second stream of hydrocarbons and aromatic hydrocarbons is fed into an alkylation unit. The alkylation unit is designed for alkylation of at least, part of aromatic hydrocarbons with at least, part of olefins in the second stream of hydrocarbons, forming alkyl aromatic hydrocarbons. At least part of the obtained alkyl aromatic hydrocarbons contains branched alkyl groups and at least, part of unreacted components of the second stream of hydrocarbons at least part of aromatic hydrocarbons and at least part of obtained alkyl aromatic hydrocarbons form an alkylation reaction stream. Alkyl aromatic hydrocarbons are separated from the alkylatio reaction stream, forming a stream of unreacted hydrocarbons and a stream of alkyl aromatic hydrocarbons, where the stream of unreacted hydrocarbons contains at least, part of unreacted components of the second stream of hydrocarbons and aromatic hydrocarbons. At least part of the paraffins and at least part of the olefins are separated from the stream of unreacted hydrocarbons, forming a stream of aromatic hydrocarbons and a stream of paraffins and unreacted olefins. At least part of the stream of paraffins and unreacted olefins is fed into a dehydrogenation unit. The dehydrogenation unit is designed for dehydrogenation of at least, part of paraffins in the stream of paraffins and unreacted olefins, with formation of olefins. At least part of the obtained olefins is extracted from the dehydrogenation unit, with formation of a stream of olefin hydrocarbons. At least part of the stream of olefin hydrocarbons is fed into the isomerisation unit.
EFFECT: use of this method saves time, reduces the cost of catalyst and/or reduces the total cost of the process flow based on a gas with low content of olefins.
23 cl, 4 tbl, 2 ex, 1 dwg
