Apparatus and method for separating ethylene cracked gasoline C8 and C9 fractions

Abstract

The invention discloses an apparatus and method for separating ethylene cracked gasoline C8 and C9 fractions. The apparatus comprises a C8-C9 cutting tower and a light component removing tower, wherein the sidewall of the lower part of the C8-C9 cutting tower is provided with a C8-containing tar inlet pipeline which is connected with the bottom outlet of a styrene extracting apparatus. The method comprises the following steps: allowing C8-C9 raw materials and C8-containing tar to enter the C8-C9 cutting tower for rectification, extracting a C8 fraction and light components from the top of the C8-C9 cutting tower, delivering the C8 fraction and the light components to the light component removing tower, extracting a cyclopentadiene by-product from the top of the light component removing tower and allowing the C8 fraction obtained at the bottom of the light component removing tower to undergo subsequent hydrogenation and styrene extraction; extracting a C9 by-product from the C8-C9 cutting tower through side drawing; and extracting tar from the bottom of the C8-C9 cutting tower. According to the invention, operation temperature is increased, promotion instead of inhibition of thermal decomposition of double ring substances is realized, and the C8 fraction with desired purity is obtained through subsequent separation, so the problem that the C8 fraction contains light components caused by decomposition of C10+; and a part of CPD and MCPD are by-produced extra.

Description

technical field [0001] The invention relates to the field of fraction separation of ethylene by-product pyrolysis gasoline, and furthermore, relates to a device and method for separating the C8C9 fraction of ethylene pyrolysis gasoline. Background technique [0002] The C8 fraction of pyrolysis gasoline contains 25-50% styrene, which can be used as the raw material of the styrene extraction device to obtain styrene products through extraction; and the C8 fraction is obtained through the C8-C9+ fraction of pyrolysis gasoline, through C8C9 The separation obtained by the cutting tower, because the styrene extraction device requires that the separated C8 fraction does not contain C9, this tower requires a large number of theoretical separation stages, and it needs to be clearly separated. [0003] In the feed of the C8C9 cutting tower, the content of dicyclopentadiene (DCPD) and methyl dicyclopentadiene (DMCPD) in the heavy components is relatively high. When the temperature is ...

AI Technical Summary

Problems solved by technology

The present invention increases the operating temperature, promotes the thermal decomposition of bicyclic substances instead of inhibiting their decomposition, and then obtains the C8 fraction with the required purity through subsequent separation to solve the problem that the C8 fraction contains light components caused by the decomposition of C10+; additional side effects Produce a CPD and MCPD

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