CN-117205854-B - Continuous tower type alcoholysis system and method for high-boiling chlorosilane

CN117205854BCN 117205854 BCN117205854 BCN 117205854BCN-117205854-B

Abstract

The invention provides a continuous tower type alcoholysis system and method for high-boiling chlorosilane, which comprises an alcohol pretreatment unit, wherein the alcohol pretreatment unit comprises an alcohol vaporizer, a demister, an alcohol superheater and a falling film type reboiler which are sequentially connected, the chlorosilane pretreatment unit comprises a falling film type evaporator, a sedimentation separator, a washing tower and a stripping tower, the alcoholysis unit comprises an alcoholysis tower, a neutralization tank and a crude esterification product storage tank which are sequentially connected, pretreated alcohol steam is introduced from the lower part of the alcoholysis tower, pretreated chlorosilane liquid is introduced from the upper part of the alcoholysis tower, the pretreated chlorosilane liquid and the alcohol sodium are discharged into the neutralization tank from the bottom of the alcoholysis tower after alcoholysis reaction in the alcoholysis tower, and after neutralization with sodium alkoxide in the neutralization tank, the liquid material is discharged into a crude esterification product storage tank.

Inventors

LIANG JINGYONG
ZHANG GUANFANG
ZHENG YUNFENG
HUANG BINGLIANG
HU JIAQI
YE TUHONG
ZHANG ZHEN
ZHOU WEI
ZHOU GUIPING
HUO BIAO

Assignees

浙江开化合成材料有限公司

Dates

Publication Date: 20260508
Application Date: 20230911

Claims (7)

1. A continuous tower alcoholysis system for high boiling chlorosilanes, comprising: The alcohol pretreatment unit comprises an alcohol vaporizer, a demister, an alcohol superheater and a falling film reboiler which are connected in sequence, wherein an alcohol raw material is vaporized by the alcohol vaporizer and then is introduced into the demister for demisting treatment, and then is introduced into the alcohol superheater and the falling film reboiler for heating treatment, so that pretreated alcohol steam is obtained; The chlorosilane pretreatment unit comprises a falling film evaporator, a sedimentation separator, a washing tower and a stripping tower, wherein the chlorosilane raw material is firstly introduced into the falling film evaporator for heating, heating and vaporizing, unvaporized liquid is discharged into the sedimentation separator, impurities are removed by the sedimentation separator, steam is discharged into the washing tower, and after washing and purifying by the washing tower, light components are removed by the stripping tower, so that pretreated chlorosilane is obtained; The alcoholysis unit comprises an alcoholysis tower, a neutralization tank and a crude esterification product storage tank which are sequentially connected, wherein pretreated alcohol steam is introduced from the lower part of the alcoholysis tower, pretreated chlorosilane liquid is introduced from the upper part of the alcoholysis tower, the pretreated chlorosilane liquid and the pretreated chlorosilane liquid are subjected to alcoholysis reaction in the alcoholysis tower, and the obtained liquid material is discharged into the neutralization tank from the bottom of the alcoholysis tower, and is neutralized with sodium alkoxide in the neutralization tank and then discharged into the crude esterification product storage tank; the part of chlorosilane after the purification treatment of the sedimentation separator is refluxed to the falling film evaporator, and the residual chlorosilane steam is introduced into the washing tower for washing and purifying treatment; Introducing clean chlorosilane discharged from the top of the washing tower into a stripping tower for further treatment, returning the materials discharged from the bottom of the washing tower to the falling film evaporator, and introducing the materials and materials from a chlorosilane raw material storage tank into the falling film evaporator for treatment; A deironing chlorosilane storage tank is arranged at the lower part of the stripping tower, wherein deironing chlorosilane is stored in the deironing chlorosilane storage tank, one part of materials in the deironing chlorosilane storage tank are sent to the upper part of the alcoholysis tower for alcoholysis reaction, and the other part of materials are sent to the upper part of the washing tower for washing gaseous materials in the deironing chlorosilane storage tank; The continuous tower type alcoholysis system of the high-boiling chlorosilane further comprises: The alcoholysis gas product treatment unit comprises a vacuum pump, a dechlorination silane tower and a hydrogen chloride purification tower, wherein alcoholysis gas products discharged from the upper part of the alcoholysis tower are firstly introduced into the upper part of a stripping tower, then pumped into the dechlorination silane tower through the vacuum pump, and are discharged into the hydrogen chloride purification tower after being treated by the dechlorination silane tower.
2. The continuous column type alcoholysis system for high boiling chlorosilane as set forth in claim 1 wherein a part of the material from the chlorosilane storage tank is fed into the falling film evaporator, another part of the material is fed into the vacuum pump, mixed with the alcoholysis gas product from the stripping column, fed into the lower part of the dechlorination column through the vacuum pump, subjected to rectification treatment by the dechlorination column, fed into the hydrogen chloride purification column from the upper part of the dechlorination column, and liquid is fed into the falling film evaporator from the lower part of the dechlorination column.
3. The continuous tower type alcoholysis system for high-boiling chlorosilane according to claim 1, wherein the alcoholysis tower comprises an alcoholysis upper tower and an alcoholysis lower tower, wherein the bottom of the alcoholysis upper tower is connected with the upper part of the alcoholysis lower tower, alcohol steam from the alcohol pretreatment unit is introduced into the lower part of the alcoholysis lower tower, chlorosilane from the chlorosilane pretreatment unit is introduced into the upper part of the alcoholysis upper tower, during the alcoholysis reaction, materials at the bottom of the alcoholysis upper tower are introduced into the alcoholysis lower tower to continue to react, materials from the top of the alcoholysis lower tower are introduced into the lower part of the alcoholysis upper tower to continue to react, the bottom of the alcoholysis lower tower is connected with the neutralization tank, liquid materials discharged from the bottom of the alcoholysis lower tower are continuously treated in the neutralization tank, and alcoholysis gas products discharged from the top of the alcoholysis upper tower are introduced into the alcoholysis gas product treatment unit to be treated.
4. The continuous column type alcoholysis system for high boiling chlorosilane according to claim 1 or 3, wherein the alcoholysis gas product treatment unit comprises a dechlorination silane lower column, a vacuum pump, a dechlorination silane upper column, a membrane compressor and a hydrogen chloride purification column, wherein alcoholysis gas products discharged from the upper part of the alcoholysis column are firstly introduced into the upper part of a stripping column, then pass through the alcohol vaporizer and enter the dechlorination silane lower column, after rectification treatment is carried out in the dechlorination silane lower column, gas is pumped from the top of the dechlorination silane lower column to the lower part of the dechlorination silane upper column by the vacuum pump, materials discharged from the bottom of the dechlorination silane lower column are introduced into the falling film evaporator, after rectification is carried out again in the dechlorination silane upper column, generated gas is discharged from the top of the dechlorination silane upper column, enters the membrane compressor, is compressed by the membrane compressor and then introduced into the hydrogen chloride purification column for rectification treatment, and liquid materials at the bottom of the dechlorination silane upper column are introduced into the upper part of the dechlorination silane upper column.
5. The continuous tower type alcoholysis system of high-boiling chlorosilane according to claim 1, wherein the alcoholysis tower comprises a metal zirconium alcoholysis tower and an enamel alcoholysis tower, wherein the bottom of the enamel alcoholysis tower is connected with the upper part of the metal zirconium alcoholysis tower, alcohol steam from the alcohol pretreatment unit is introduced into the lower part of the metal zirconium alcoholysis tower, chlorosilane from the chlorosilane pretreatment unit is introduced into the upper part of the enamel alcoholysis tower, during the alcoholysis reaction, materials at the bottom of the enamel alcoholysis tower are introduced into a metal zirconium Jie Da for continuous reaction, materials from the top of the metal zirconium alcoholysis tower are introduced into an enamel alcoholysis tower for continuous reaction, the bottom of the metal zirconium alcoholysis tower is connected with the neutralization tank, liquid materials discharged from the bottom of the metal zirconium alcoholysis tower are continuously treated in the neutralization tank, and alcoholysis gas products discharged from the top of the enamel alcoholysis tower are introduced into an alcoholysis gas product treatment unit for continuous treatment.
6. The continuous tower alcoholysis system of high boiling chlorosilane as in claim 1 wherein the alcohol vaporizer, falling film reboiler and stripper are zirconium equipment and the demister, alcohol superheater and scrubber are pure nickel equipment.
7. A continuous tower type alcoholysis method of high-boiling chlorosilane is characterized in that the continuous tower type alcoholysis system of any one of claims 1-6 is adopted to carry out alcoholysis of chlorosilane.

Description

Continuous tower type alcoholysis system and method for high-boiling chlorosilane Technical Field The invention relates to the technical field of organic silicon, in particular to a continuous tower type alcoholysis system and method for high-boiling chlorosilane. Background In the production process of the organic silicon product, when high-boiling chlorosilane with more than 2 chlorine atoms connected on silicon atoms reacts with alcohol to form alkoxy silane, crosslinking and curing reaction easily occurs, equipment is blocked, and if the high-boiling chlorosilane cannot be converted and utilized through low-cost alcoholysis, a large amount of high-boiling chlorosilane can be accumulated and stored in a chemical plant, the benefit and safety can be seriously influenced. In addition, for high boiling special chlorosilane monomers such as phenylchlorosilane, long-chain alkane chlorosilane and the like, a low-cost continuous tower type alcoholysis esterification process is also required to process to improve the yield and purity. However, the high-boiling chlorosilane has large molecular structure steric hindrance, so that the reaction between the high-boiling chlorosilane and alcohol can be completed only at a higher reaction temperature for a longer time, but if the reaction temperature is increased, the reaction between the alcohol and hydrogen chloride is accelerated to generate chlorinated alkane and water, and the water is extremely easy to carry out crosslinking and curing reaction with the chlorosilane, so that equipment is blocked. In addition, when the raw materials contain iron impurities or equipment factors to enable the raw materials in the reaction to be in contact with ferric trichloride, the ferric trichloride has strong catalytic action, so that alcohol and hydrogen chloride can react to generate chlorinated alkane and water, and the crosslinking and curing reaction is easier to occur. When a continuous alcoholysis process is used for large-scale treatment of high-boiling chlorosilanes, if the reaction temperature is low and an alcohol steam stripping acid-expelling tower reaction process is adopted under normal pressure or pressurization, the vapor pressure of a mixture of high-boiling chlorosilanes in a liquid phase and alkoxysilane obtained by partial alcoholysis thereof is low so that the saturated dissolution capacity is high, alcohols and hydrogen chloride are easily dissolved in the liquid phase in a large amount at the same time, and water is easily generated when iron impurities existing in the liquid phase catalyze the reaction, so that the crosslinking and curing reaction occurs. However, the existing continuous tower reaction method does not carry out iron removal treatment on raw materials, and does not have measures for preventing the high-freezing-point chlorosilane from solidifying and blocking refrigeration equipment of a hydrogen chloride separation system, so that the high-boiling-point chlorosilane cannot be treated. In addition, most of the existing processes adopt enamel or glass-lined tower equipment to finish the alcoholysis reaction process of chlorosilane, the equipment has a plurality of tower sections and a plurality of sealing surfaces, the tower sections are easy to damage when impacted by vibration, the sealing of the tower sections is usually sealed by a tetrafluoro-coated soft cushion, and the gasket is easy to deform and lose efficacy at high temperature, so that the sealing gasket is frequently replaced. Even more serious, if the equipment is frequently shut down and disassembled to replace the sealing gasket, materials are exposed to the atmosphere, so that field equipment facilities are severely corroded and damaged, and the maintenance cost of the equipment is increased. In addition, the enamel porcelain tower and the enamel glass tower are limited by the allowable bearing capacity of the anti-corrosion layer and the gasket, so that the adopted single tower is limited in height, the residence time required by the alcoholysis reaction of the high-boiling chlorosilane is difficult to meet when the single tower is used, but the problem of local acid removal is formed by adopting multi-tower serial connection, and the system structure is complicated and the operation is complicated. In addition, the temperature rise and fall operation of enamel glass lining equipment is required to be slow, because the thermal stress caused by temperature difference impact easily damages the anti-corrosion layer of the equipment, and the high-temperature running operation is difficult. Under the current vigorous development of organosilicon industry in China, a continuous tower type alcoholysis system and method for high-boiling chlorosilane are provided, so that the chlorosilane alcoholysis process can run stably and efficiently for a long time, and the method has a particularly important significance. Disclosure of Invention The invention designs a continuous tower type