Method for heating ethylbenzene by ethylbenzene dehydrogenation reaction

Abstract

The invention relates to a heating method of ethyl benzene of an ethyl benzene dehydrogenation reaction material, which mainly solves the problems of frequent accidents of the combined heat exchanger, difficult long-period and stable running, large pressure drop in the pipeline of a reactive system and inadequate heat recovery of a reactor charging / discharging three-level combined heat exchanger in the traditional styrene device due to the unreasonable flow for heating the ethyl benzene by utilizing the discharging of the high temperature reactor. The invention adopts the technical proposals that a liquid phase ethyl benzene material and ingredient water vapor are firstly vaporized to a gas phase with a temperature of between 90 and 110 DEG C through an independently arranged evaporator, and then enter the third level shell pass of the reactor charging / discharging combined heat exchanger to be preheated to a temperature of between 200 and 250 DEG C and then enter the first level shell pass of the reactor charging / discharging combined heat exchanger for being super-heated to a temperature of between 450 and 550 DEG C by the discharging of the high temperature reactor, and the second level shell pass of the reactor charging / discharging combined heat exchanger is used for generating saturated water vapor with a pressure of between 400KPaA and 1000KPaA; and the reactor charging / discharging three-level combined heat exchanger adopts the horizontal or vertical straight-line type arrangement mode, a linear type pipeline expansion joint is disposed between an exit of a dehydrogenation reactor and a material inlet of the first level in the reactor charging super-heater, namely the three-level combined heat exchanger to maintain the shortest distance for allowing installation between the dehydrogenation reactor and the charging super-heater, thereby reducing the tube shell pass thermal expansion difference of the first level heat exchanger.

Description

technical field [0001] The invention relates to a heating method of ethylbenzene, a raw material for ethylbenzene dehydrogenation reaction. Specifically, it relates to a method for heating raw material ethylbenzene by utilizing the high-temperature discharge of a reactor for producing styrene by negative pressure adiabatic catalytic dehydrogenation of ethylbenzene. Background technique [0002] Styrene is one of the most important basic organic chemical raw materials for the manufacture of polystyrene PS and EPS (about 66.7%), copolymer resins such as ABS and SAN (about 11.5%), styrene / butadiene copolymerization Latex SB (about 5.3%), styrene-butadiene rubber and latex SBR (about 5.3%), unsaturated polyester (about 4.1%), and others such as styrene / methyl methacrylate latex, methyl methacrylate Ester / butadiene / styrene copolymer MBS, ion exchange resins and drugs (accounting for about 5.6%). [0003] Due to the strong growth in the consumption of downstream products of styr...

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Problems solved by technology

[0018] The technical problem to be solved by the present invention is that in the traditional styrene plant, the three-stage combined heat exchanger for the feed and output of the reactor is unreasonable due to the unreasonable process of heating ethylbenzene with the high-temperature reactor discharge, resulting in frequent accidents in the combined heat exchanger. It is difficult to run stably for a long period of time, and the pressure drop in the pipeline in the reaction system is large, and the heat recovery is insufficient. A new heating method for ethylbenzene, a raw material for ethylbenzene dehydrogenation, is provided

This method can reduce the difference in thermal expansion of the tube and shell side of the first-stage heat exchanger, eliminate the erosion of the tube side by the material inlet of the third-stage heat exchanger, and better solve the problem that they are easy to leak, and the pressure drop of the entire reaction system is small. , the heat loss is small, and the high-temperature sensible heat energy has been fully recycled.

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