A system for reducing hydrogen chloride content in organosilicon hydrolysate

Abstract

The utility model discloses a system of reducing hydrogen chloride content in organic silicon hydrolyzate, characterized in that it comprises dimethyl hydrolyzate storage tank, moisture adsorption tower and HCL adsorption tower, the dimethyl hydrolyzate storage tank is connected with the top feed inlet of moisture adsorption tower through hydrolyzate delivery pump, the bottom discharge port of moisture adsorption tower is connected with the top feed inlet of HCL adsorption tower through first filter and moisture adsorption tower bottom pump in proper order, the bottom discharge port of HCL adsorption tower is connected with product storage tank for storing high-purity siloxane through second filter and HCL adsorption tower bottom pump in proper order, a water content detection sampling point is arranged on the connecting pipeline between moisture adsorption tower bottom pump and HCL adsorption tower, an HCL content detection sampling point is arranged on the connecting pipeline between HCL adsorption tower bottom pump and product tank, and the advantage is that water and HCL in dimethyl hydrolyzate are adsorbed and removed, and product purity is improved.

Description

Technical Field

[0001] This utility model relates to the field of organosilicon production technology, and in particular to a system for reducing the hydrogen chloride content in organosilicon hydrolysates. Background Technology

[0002] Organosilicon products are widely used in electronics, electrical appliances, building materials, light industry, and various other industries. In production, the main reaction process includes: the synthesis of chloromethane; the reaction of chloromethane with silicon powder to produce crude monomers (i.e., a mixture of chlorosilanes, the main product of which is dimethyldichlorosilane); the hydrolysis of the crude monomers to obtain hydrolysates (i.e., mixed siloxanes); and the polymerization of these hydrolysates to obtain polysiloxanes, which are then processed into products such as silicone rubber, silicone resin, and silicone oil. The presence of hydrogen chloride in siloxanes reduces the molecular weight of polysiloxanes, affecting product quality and material performance. Current hydrolysis processes employ multi-stage hydrolysis and multi-stage phase separation techniques. However, this method can only purify siloxanes to 99.9% wt. Further purification of siloxanes and reduction of hydrogen chloride content remains a serious challenge for all manufacturers. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a system for adsorbing and removing water and HCl from dimethyl hydrolysate, thereby improving the purity of the product and reducing the hydrogen chloride content in organosilicon hydrolysate.

[0004] The technical solution adopted by this utility model to solve the above-mentioned technical problems is as follows: a system for reducing the hydrogen chloride content in organosilicon hydrolysate, comprising a dimethyl hydrolysate storage tank, a moisture adsorption tower, and an HCl adsorption tower. The dimethyl hydrolysate storage tank is connected to the top inlet of the moisture adsorption tower via a hydrolysate transfer pump. The bottom outlet of the moisture adsorption tower is connected to the top inlet of the HCl adsorption tower via a moisture adsorption tower bottom pump. The bottom outlet of the HCl adsorption tower is connected to a product storage tank for storing high-purity siloxanes via an HCl adsorption tower bottom pump.

[0005] Furthermore, a water content detection sampling point is installed on the connecting pipeline between the bottom pump of the moisture adsorption tower and the HCl adsorption tower.

[0006] Furthermore, an HCl content detection sampling point is installed on the connecting pipeline between the HCl adsorption tower bottom pump and the product storage tank.

[0007] Furthermore, it also includes an electric heater for heating the regenerated gas, the electric heater being connected to the bottom of the moisture adsorption tower and the bottom of the HCl adsorption tower respectively.

[0008] Furthermore, a first filter is installed on the connecting pipeline between the bottom outlet of the moisture adsorption tower and the bottom pump of the moisture adsorption tower.

[0009] Furthermore, a second filter is installed on the connecting pipeline between the bottom outlet of the HCl adsorption tower and the bottom pump of the HCl adsorption tower.

[0010] Furthermore, a liquid distributor is provided at the top of both the moisture adsorption tower and the HCl adsorption tower.

[0011] Compared with the prior art, the advantages of this utility model are:

[0012] 1. It adsorbs and removes water and HCl from dimethyl hydrolysate, resulting in significant product purification. It can reduce the residual hydrogen chloride content in siloxane to 0.1 ppm and the water content to 1 ppm.

[0013] 2. A two-stage adsorption tower is adopted. The first stage dehydrates the water and the second stage removes HCl, which can reduce the impact of the presence of water on the adsorption of HCl by the molecular sieve.

[0014] 3. Compared with distillation columns, the two-step adsorption and removal process has the advantages of lower equipment investment, smaller footprint, and lower energy consumption. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the system for reducing the hydrogen chloride content in organosilicon hydrolysate according to this invention; the following labels are provided in the diagram: 1-dimethyl hydrolysate storage tank, 2-hydrolysate transfer pump, 3-moisture adsorption tower, 4-first filter, 5-moisture adsorption tower bottom pump, 6-water content detection sampling point, 7-HCl adsorption tower, 8-second filter, 9-HCl adsorption tower bottom pump, 10-HCl content detection sampling point, 11-electric heater, 12-product storage tank. Detailed Implementation

[0016] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of the embodiments of this utility model application. Therefore, the drawings and description are considered to be exemplary in nature and not restrictive.

[0017] The utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0018] A system for reducing the hydrogen chloride content in organosilicon hydrolysate includes a dimethyl hydrolysate storage tank 1, a moisture adsorption tower 3, and an HCl adsorption tower 7. The dimethyl hydrolysate storage tank 1 is connected to the top inlet of the moisture adsorption tower 3 via a hydrolysate transfer pump 2. The bottom outlet of the moisture adsorption tower 3 is connected to the top inlet of the HCl adsorption tower 7 via a first filter 4 and a bottom pump 5. The bottom outlet of the HCl adsorption tower 7 is connected to a product storage tank 12 for storing high-purity siloxanes via a second filter 8 and a bottom pump 9.

[0019] In this specific embodiment, a water content detection sampling point is installed on the connecting pipeline between the moisture adsorption tower bottom pump 5 and the HCl adsorption tower 7. An HCl content detection sampling point is installed on the connecting pipeline between the HCl adsorption tower bottom pump 9 and the product storage tank. The system also includes an electric heater 11 for heating the regeneration gas, which is connected to the bottom of both the moisture adsorption tower 3 and the HCl adsorption tower 7.

[0020] The working process of the above-mentioned system for reducing the hydrogen chloride content in organosilicon hydrolysates is as follows:

[0021] 1. Primary Dehydration Process. The dimethyl hydrolysate, after multi-stage hydrolysis and phase separation, is pumped from the dimethyl hydrolysate storage tank 1 to the top of the moisture adsorption tower 3 via the hydrolysate transfer pump 2. The tower is filled with 3A molecular sieves with a particle size of 1-2 mm. A liquid distributor is installed at the top of the tower to ensure uniform material distribution and wetting of the molecular sieves. The adsorption temperature inside the tower is 25-50℃, and the operating pressure is 0.1-0.3 MPa. After adsorption by the molecular sieves, the material exits from the bottom of the tower. A first filter 4 is installed on the pipeline between the bottom of the moisture adsorption tower 3 and the bottom pump 5, which filters out solid residues from the material. After filtration, the material is pumped by the bottom pump 5 to the top of the HCl adsorption tower 7. A water content detection sampling point 6 is installed on the pipeline. When the detected water content drops to 1 ppm, the material is transported to the top of the HCl adsorption tower 7. When the detected water content exceeds 1 ppm, the operation of the moisture adsorption tower 3 is switched to standby mode, and the moisture adsorption tower 3 enters regeneration mode.

[0022] 2. Two-stage HCl removal process. The material enters the HCl adsorption tower 7, which is filled with modified 13X molecular sieves to adsorb HCl from the material. The adsorption temperature of the HCl adsorption tower 7 is 20~45℃, and the operating pressure is 0.1-0.3MPa. After adsorption by the molecular sieve, the material exits from the bottom of the tower, is filtered by the second filter 8, and then sent to the next reaction unit by the HCl adsorption tower bottom pump 9. An HCl content detection sampling point 10 is installed on the outlet pipeline of the HCl adsorption tower bottom pump 9. When the detected HCl content decreases to 0.1ppm, the obtained high-purity siloxane is sent to the next unit. When the detected HCl content is higher than 1ppm, the operation of the HCl adsorption tower 7 is switched to standby mode, and the HCl adsorption tower 7 enters regeneration mode.

[0023] 3. Adsorption Tower Regeneration. Nitrogen gas is used for regeneration. The regeneration time for moisture adsorption tower 3 is 48 hours, and the regeneration time for HCl adsorption tower 7 is 72 hours. Before startup, the system is purged with nitrogen until the oxygen content is <50ppm. Then, the nitrogen is heated to 150~250℃ through electric heater 11 and introduced into the bottom of moisture adsorption tower 3 and the bottom of HCl adsorption tower 7, respectively. The regeneration waste gas is discharged from the top of each tower and, after washing, meets emission standards.

[0024] The above description is not intended to limit the present invention, nor is the present invention limited to the examples given above. Any changes, modifications, additions, or substitutions made by those skilled in the art within the scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A system for reducing the hydrogen chloride content in organosilicon hydrolysates, characterized in that: The system includes a dimethyl hydrolysate storage tank, a moisture adsorption tower, and an HCl adsorption tower. The dimethyl hydrolysate storage tank is connected to the top inlet of the moisture adsorption tower via a hydrolysate transfer pump. The bottom outlet of the moisture adsorption tower is connected to the top inlet of the HCl adsorption tower via a moisture adsorption tower bottom pump. The bottom outlet of the HCl adsorption tower is connected to a product storage tank for storing high-purity siloxanes via an HCl adsorption tower bottom pump.

2. The system for reducing the hydrogen chloride content in organosilicon hydrolysate according to claim 1, characterized in that: A water content detection sampling point is installed on the connecting pipeline between the bottom pump of the moisture adsorption tower and the HCl adsorption tower.

3. The system for reducing the hydrogen chloride content in organosilicon hydrolysate according to claim 1, characterized in that: An HCl content detection sampling point is installed on the connecting pipeline between the bottom pump of the HCl adsorption tower and the product storage tank.

4. The system for reducing the hydrogen chloride content in organosilicon hydrolysate according to claim 1, characterized in that: It also includes an electric heater for heating the regenerated gas, the electric heater being connected to the bottom of the moisture adsorption tower and the bottom of the HCl adsorption tower respectively.

5. The system for reducing the hydrogen chloride content in organosilicon hydrolysate according to claim 1, characterized in that: A first filter is installed on the connecting pipeline between the bottom outlet of the moisture adsorption tower and the bottom pump of the moisture adsorption tower.

6. The system for reducing the hydrogen chloride content in organosilicon hydrolysate according to claim 1, characterized in that: A second filter is installed on the connecting pipeline between the bottom outlet of the HCl adsorption tower and the bottom pump of the HCl adsorption tower.

7. The system for reducing the hydrogen chloride content in organosilicon hydrolysate according to claim 1, characterized in that: The moisture adsorption tower and the HCl adsorption tower are equipped with liquid distributors at the top.

Images