A kind of separation method of C9~C10 fraction

Abstract

A method for separating C9-C10 fractions, comprising: vacuum rectification and separation of raw materials in a vacuum rectification tower, enriched styrene and methyl styrene fractions are obtained from the top of the tower, and remaining fractions are obtained from the tower reactor; the materials in the tower reactor enter The depolymerization and rectification tower is used for depolymerization and rectification, the top of the tower is rich in cyclopentadiene fraction, the side line is the material of methylcyclopentadiene, and the tower still is the mixed fraction of indene and remaining dicyclopentadiene; the tower still fraction enters The vacuum rectification tower carries out vacuum rectification, and the mixed fraction rich in indene and dicyclopentadiene is obtained at the top of the tower, and the heavy component impurities are obtained in the bottom of the tower; the fraction rich in indene and dicyclopentadiene enters the depolymerization rectification tower for Depolymerization and rectification, the cyclopentadiene fraction is obtained at the top of the tower, and the indene-rich fraction is obtained at the bottom of the tower. The invention obtains high-purity cyclopentadiene and methyl cyclopentadiene while obtaining high-quality petroleum resin raw materials; the dimerization reaction is greatly reduced in the rectification separation process, the generation of polymers is avoided, and the single-pass product yield is improved. Higher, also solved the contradiction of dicyclopentadiene and indene separation difficulty.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and particularly relates to a method for separating and utilizing C9-C10 fractions of ethylene by-products produced from petroleum cracking, that is, the C9-C10 fractions are depolymerized, separated and other methods to obtain high-quality petroleum resin raw materials. Background technique [0002] The C9-C10 fraction is the remaining fraction after the C5 fraction and the C6-C8 fraction are separated from the by-products of naphtha or light oil cracking, accounting for about 10% to 20% of the ethylene production. The composition of C9~C10 fractions is complex, with about 150 components. This fraction mainly contains aromatics above C9, styrene, methylstyrene, dicyclopentadiene (DCPD), indene, naphthalene and other components and cyclopentadiene. Various forms of self-polymerized and interpolymerized dimers of ethylene (CPD) and methylcyclopentadiene (MCPD), among which methylstyrene and d...

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Problems solved by technology

[0005] It can be seen that the utilization of C9-C10 fractions in the prior art is only to produce CPD and MCPD by depolymerization and separation, or only the rectification and cutting of C9 raw materials are used as raw materials for petroleum resins, and the C9 raw materials are not fully utilized. and in the process of vacuum distillation C9 raw material, due to the higher concentration of DCPD, the proportion of styrene, methylstyrene and indene is relatively low, and the boiling points of DCPD and methylstyrene and indene are not much different. It is closer under reduced pressure. To obtain a higher fraction, a larger reflux ratio is required, and more methyl styrene is lost.

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