Apparatus and method for separating styrene from hydrocarbons mixture

Abstract

The invention relates to an apparatus and a method for separating styrene from a hydrocarbons mixture. The apparatus comprises an extraction rectifying tower provided with a separation wall, a tower top condenser and a tower top product buffer tank communicated with discharging at tower top, a lateral line condenser and a lateral line product buffer tank communicated with discharging at lateral line, and a reboiler, the separation wall is positioned at central section of the rectifying tower along the axial direction, a top with a closure cap is connected with the side tower wall, the inner part of the extraction rectifying tower is divided into a common rectifying section (1), an extraction rectifying section (2), a common stripping section (4) and a solvent recovery section (3) in order, an inlet for mixing the hydrocarbons raw material is arranged at the extraction rectifying section (2), a solvent inlet is arranged at the bottom of the common rectifying section (1), and the lateral line product outlet is arranged at the upper part of the solvent recovery section (3). The apparatus and method have the advantages that the styrene separation efficiency is high, the apparatus investment is reduced, and the energy consumption is reduced.

Description

technical field [0001] The present invention relates to a kind of hydrocarbon mixture separation device and method, more particularly, relate to a kind of device and method for recovering styrene from hydrocarbon mixture by extractive distillation. Background technique [0002] Styrene monomer is an important basic organic chemical raw material, and it is also widely used in coatings, pesticides, and medicine. According to statistics, the by-product steam cracking gasoline of ethylene cracking unit contains 3-5% styrene. The traditional processing method is for pyrolysis gasoline C 6 -C 8 The distillate undergoes two-stage hydrogenation, in which styrene is saturated into ethylbenzene, which not only causes the concentration of ethylbenzene in the mixed xylene to be too high to be used as isomerization grade xylene, but also wastes a lot of hydrogen resources. In contrast, the direct separation of styrene from pyrolysis gasoline is an attractive technology. However, due ...

AI Technical Summary

Problems solved by technology

In order to separate and obtain styrene with a purity of more than 99.5%, the theoretical plate of the rectification column must exceed 150, and the reflux ratio must be greater than 100, which cannot be realized in practical applications.

CN101723793A discloses a method for separating crude styrene from pyrolysis gasoline by using a dividing wall tower, but there is a problem that the product purity is not high and further separation is required

The process is a traditional two-tower process, and because the preferred dimethylacetamide solvent has a low boiling point (165° C.), and the difference between the boiling points of toluene and styrene is too small, the energy consumption of the process is high.

[0004] In the prior art styrene separation process, there are problems of long separation process, high energy consumption, and low separation efficiency. The styrene separation process still has a lot of room for energy saving and consumption reduction.

Images