Apparatus for producing methylchlorosilane by disilane cleavage

Abstract

This utility model relates to an apparatus for producing methylchlorosilane from disilane by cracking, comprising: a cracking reactor, a cracking distillation column, a cooler, and a reflux tank; the cracking distillation column is provided with a bottom inlet, a top outlet, and a side-stream outlet, the bottom inlet of the cracking distillation column being connected to the gas phase outlet of the cracking reactor via a pipeline; the cracking distillation column is provided with a packing layer and a liquid collection structure located between the packing layer and the bottom inlet, the liquid collection structure being connected to the side-stream outlet; the side-stream outlet is connected to a side-stream outlet pipeline for collecting liquid phase material; the cooler is connected to the top outlet of the cracking distillation column for cooling the crude product from the cracking distillation column; the inlet of the reflux tank is connected to the cooler; the reflux tank is provided with a discharge pipeline and a reflux pipeline for returning the crude product to the top of the cracking distillation column. This utility model's apparatus can extend the cracking start-up cycle, save maintenance costs, increase product yield, and improve the efficiency of the disilane cracking reaction.

Description

Technical Field

[0001] This invention belongs to the field of organosilicon technology, and specifically relates to an apparatus for producing methylchlorosilane by cracking disilane. Background Technology

[0002] Disilanes mainly include MeCl2Si-SiMeCl2 (1,1,2,2-tetrachloro-1,2-dimethyldisilane, abbreviated as "Me1,1"), Me2ClSi-SiMeCl2 (1,1,2-trichloro-1,2,2-trimethyldisilane, abbreviated as "Me2,1"), Me3Si-SiMeCl2 (1,1-dichloro-1,2,2,2-tetramethyldisilane, abbreviated as "Me3,1"), and Me2ClSi-SiMe2Cl (1,2- Dichloro-1,1,2,2-tetramethyldisilane (abbreviated as "Me2,2"), Me3Si-SiMe2Cl (1-chloro-1,1,2,2,2-pentamethyldisilane (abbreviated as "Me3,2"), and Me3Si-SiMe3 (1,1,1,2,2,2-hexamethyldisilane (abbreviated as "Me3,3"), wherein Me1,1, Me2,1 and Me3,1 are crackable disilane, while Me2,2, Me3,2 and Me3,3 are non-crackable disilane.

[0003] The conventional process for producing methylchlorosilane by disilane cracking includes: (1) adding disilane and HCl gas into a reactor for reaction; (2) using the temperature of the reactor, the gaseous material containing the cracking crude product (mainly including M1(MeSiCl3), M2(Me2SiCl2), M3(Me3SiCl and MH(MeHSiCl2)) and disilane is fed into a cracking distillation column for distillation, obtaining the cracking crude product from the top of the column and disilane from the bottom; (3) the cracking crude product is stored in a reflux tank, with a portion returned to the cracking distillation column as reflux and a portion sent to a storage tank; (4) the disilane from the bottom of the cracking distillation column is refluxed back into the reactor for reaction. The feed of disilane is controlled by the liquid level in the reactor. When the reactor mainly contains non-crackable disilane (such as Me2,2, Me3,2, Me3,3) and methylene silicides, the reaction stops. In addition, the reaction can be judged to be complete by the pressure rise in the reactor caused by the lack of HCl consumption.

[0004] However, such a process has the following drawbacks: (1) short cracking cycle and large catalyst consumption; (2) accumulation of non-crackable substances in the reactor affects the reaction efficiency; (3) high cost of shutdown and maintenance after the reaction stops. Utility Model Content

[0005] Therefore, the purpose of this utility model is to provide an apparatus for producing methylchlorosilane by cracking disilane, addressing at least one technical defect in the prior art.

[0006] This utility model provides an apparatus for the pyrolysis of disilane to produce methylchlorosilane, wherein the apparatus includes a pyrolysis kettle, a pyrolysis distillation column, a cooler, and a reflux tank; wherein,

[0007] The pyrolysis reactor is equipped with a disilane inlet, an HCl inlet, a catalyst inlet, and a gas phase outlet;

[0008] The cracking distillation column is provided with a bottom inlet, a top outlet, and a side-stream outlet. The bottom inlet of the cracking distillation column is connected to the gas phase outlet of the cracking vessel via a pipeline. The cracking distillation column is provided with a packing layer and a liquid collection structure located between the packing layer and the bottom inlet. The liquid collection structure is connected to the side-stream outlet. The side-stream outlet is connected to a side-stream outlet pipeline for collecting liquid phase material.

[0009] The cooler is connected to the top outlet of the cracking distillation column and is used to cool the crude product from the cracking distillation column;

[0010] The inlet of the reflux tank is connected to the cooler and is used to receive and store crude product from the cooler; the reflux tank is provided with a discharge line and a reflux line for returning the crude product stored in the reflux tank to the top of the cracking distillation column.

[0011] Preferably, the liquid collection structure includes a liquid phase collection tank and a collection tray. The liquid phase collection tank includes a bottom plate, a guide plate, and a baffle. The size of the bottom plate is smaller than the cross-sectional size of the cracking distillation column. The guide plate and the baffle are mounted on the bottom plate. The guide plate has an inclined plate portion arranged obliquely upward from the center of the cracking distillation column. The baffle is disposed on the side opposite to the inclination direction of the inclined plate portion and forms a groove with the guide plate on the bottom plate. The collection tray includes a vertical plate and an annular plate. The inner edge of the annular plate is connected to the bottom plate via the vertical plate, and the outer edge of the annular plate is connected to the inner wall of the cracking distillation column, thereby forming an annular collection cavity. The groove communicates with the annular collection cavity.

[0012] Preferably, the angle between the inclined plate and the vertical direction is 10-60°.

[0013] More preferably, the angle between the inclined plate portion and the vertical direction is 20-45°.

[0014] Preferably, the base plate is provided with an opening for gaseous material to pass through, the opening being located below the inclined plate and covered by the projection of the inclined plate onto the base plate.

[0015] Preferably, the ratio of the diameter of the bottom plate to the diameter of the cracking distillation column is 0.6-0.8:1.

[0016] Preferably, the side outlet is located on the side wall of the annular collection chamber of the cracking distillation column.

[0017] Preferably, a liquid seal pipeline is provided on the pipeline connecting the bottom inlet of the cracking distillation column and the gas phase outlet of the cracking vessel.

[0018] Preferably, the bottom of the pyrolysis vessel is provided with a drain port.

[0019] Preferably, the bottom of the cracking distillation column is provided with a drain port.

[0020] This invention has the following advantages: (1) it can extend the cracking start-up cycle, save maintenance costs, and increase product output; (2) it can improve the efficiency of disilane cracking reaction. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of one embodiment of the device of this utility model;

[0022] Figure 2 This is a schematic diagram of one embodiment of the liquid collection structure of the device of this utility model;

[0023] Among them, 1. HCl feed line; 2. Disilane feed line; 3. Catalyst feed line; 4. Cracking reactor; 5. Cracking distillation column; 6. Side feed line; 7. Discharge line; 8. Cooler; 9. Reflux tank; 10. Reflux line; 510. Packing layer; 521. Inclined plate section; 522. Baffle; 523. Bottom plate; 524. Vertical plate; 525. Ring plate; 526. Groove; 527. Opening; 530. Side feed outlet. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments, but this does not constitute any limitation on the present invention.

[0025] This utility model provides an apparatus for the pyrolysis of disilane to produce methylchlorosilane, wherein the apparatus includes a pyrolysis kettle, a pyrolysis distillation column, a cooler, and a reflux tank; wherein,

[0026] The pyrolysis reactor is equipped with a disilane inlet, an HCl inlet, a catalyst inlet, and a gas phase outlet;

[0027] The cracking distillation column is provided with a bottom inlet, a top outlet, and a side-stream outlet. The bottom inlet of the cracking distillation column is connected to the gas phase outlet of the cracking vessel via a pipeline. The cracking distillation column is provided with a packing layer and a liquid collection structure located between the packing layer and the bottom inlet. The liquid collection structure is connected to the side-stream outlet. The side-stream outlet is connected to a side-stream outlet pipeline for collecting liquid phase material.

[0028] The cooler is connected to the top outlet of the cracking distillation column and is used to cool the crude product from the cracking distillation column;

[0029] The inlet of the reflux tank is connected to the cooler and is used to receive and store crude product from the cooler; the reflux tank is provided with a discharge line and a reflux line for returning the crude product stored in the reflux tank to the top of the cracking distillation column.

[0030] Figure 1-2 A schematic diagram of the apparatus for producing methylchlorosilane by disilane pyrolysis according to this invention is shown.

[0031] Reference Figure 1-2 The apparatus for producing methylchlorosilane by disilane cracking according to this invention includes a cracking vessel 4, a cracking distillation column 5, a cooler 8, and a reflux tank 9.

[0032] The cracking reactor 4 is equipped with a disilane inlet, an HCl inlet, a catalyst inlet, and a gas phase outlet.

[0033] The cracking distillation column 5 is equipped with a bottom inlet, a top outlet, and a side-stream outlet 530. The bottom inlet of the cracking distillation column 5 is connected to the gas phase outlet of the cracking vessel 4 via a pipeline. The cracking distillation column 5 is equipped with a packing layer 510 and a liquid collection structure located between the packing layer 510 and the bottom inlet. The liquid collection structure is connected to the side-stream outlet 530; the side-stream outlet 530 is connected to a side-stream outlet pipeline 6 for collecting liquid phase material.

[0034] Cooler 8 is connected to the top outlet of crack distillation column 5 and is used to cool the crude product from crack distillation column 5.

[0035] The inlet of the reflux tank 9 is connected to the cooler 8, and is used to receive and store the crude product from the cooler 8. The reflux tank 9 is provided with a discharge line 7 and a reflux line 10 for returning the crude product stored in the reflux tank 9 to the top of the cracking distillation column 5.

[0036] Me1,1, Me2,1, and Me3,1 are crackable disilanes that react with HCl in the presence of a catalyst such as tri-n-butylamine to produce a mixture of crude methylchlorosilane monomers, namely, monomethyltrichlorosilane (M1), dimethyldichlorosilane (M2), trimethylmonochlorosilane (M3), and monomethyldichlorohydrosilane (MH), with boiling points between 40-70°C. Me2,2, Me3,2, and Me3,3 are non-crackable disilanes with boiling points between 110-150°C, typically around 120°C.

[0037] Reference Figure 1-2 The disilane inlet, HCl inlet, and catalyst inlet are connected to disilane inlet line 2, HCl inlet line 1, and catalyst inlet line 3, respectively. HCl, disilane, and catalyst enter the cracking reactor 4 through HCl inlet line 1, disilane inlet line 2, and catalyst inlet line 3, respectively, to react and generate a mixture of crude methylchlorosilane monomers (referred to as "crude monomers" or "crude products"). The reaction temperature in the cracking reactor 4 can typically be controlled at around 100-160℃ (the boiling point of non-crackable disilane is around 120℃), and the reactor pressure can be controlled at 0-0.1MPa. The material containing the cracked crude monomers, crackable disilane, and non-crackable disilane is vaporized (gas phase material) and enters the cracking distillation column 5 for processing.

[0038] In the cracking distillation column 5, the top operating pressure is typically 0-0.05 MPa, the top operating temperature is 70-100℃, and the distillation temperature is 100-110℃. Due to the difference in boiling points, in the cracking distillation column 5, the crude monomer mixture of methylchlorosilanes with lower boiling points (crude product) is collected from the top of the column, while the non-crackable disilanes with higher boiling points are collected in the middle and lower part of the column by the liquid collection structure and discharged via side outlet 530 and side outlet line 6. The crude product from the top of the cracking distillation column 5 is stored in the reflux tank 9 after passing through the cooler 8. Part of the crude product in the reflux tank 9 is returned to the top of the cracking distillation column 5 via the reflux line 10, and part of the crude product is discharged via the discharge line 7.

[0039] The crude product collected from the top of cracking distillation column 5 contains 80-90% crude methylchlorosilane monomers of monomethyltrichlorosilane, dimethyldichlorosilane, trimethylmonochlorosilane, and monomethyldichlorohydrosilane, 2-10% crackable disilane, and 0-1% non-crackable disilane.

[0040] The liquid phase material extracted from the side stream contains 90%-95% non-pyrolytic disilanes Me2,2,Me3,2 and Me3,3, and 5-10% mixed crude monomers of methylchlorosilanes.

[0041] This invention helps to extend the reaction cycle and improve the efficiency of disilane cracking reaction by timely removing non-crackable disilane from the cracking distillation column 5 and preventing it from flowing back into the cracking vessel 4 and accumulating.

[0042] In some embodiments, the liquid collection structure includes a liquid collection tank and a collection tray. The liquid collection tank includes a bottom plate 523, a guide plate, and a baffle 522. The bottom plate 523 is smaller than the cross-sectional dimension of the cracking distillation column 5. The guide plate and the baffle 522 are mounted on the bottom plate 523. The guide plate has an inclined plate portion 521 arranged obliquely upward from the center of the cracking distillation column 5. The baffle 522 is disposed on the side opposite to the inclination direction of the inclined plate portion 521 and forms a groove 526 with the guide plate on the bottom plate 523. The collection tray includes a vertical plate 524 and an annular plate 525. The inner edge of the annular plate 525 is connected to the bottom plate 523 via the vertical plate 524, and the outer edge of the annular plate 525 is connected to the inner wall of the cracking distillation column 5, thereby forming an annular collection cavity. The groove 526 communicates with the annular collection cavity.

[0043] In some embodiments, the angle between the inclined plate portion 521 and the vertical direction is 10-60°. By setting the inclination angle, the liquid phase collection area can be increased, thereby ensuring sufficient collection of liquid phase materials.

[0044] In some preferred embodiments, the angle between the inclined plate portion 521 and the vertical direction is 20-45°.

[0045] In some embodiments, the base plate 523 is provided with an opening 527 for the passage of gaseous material. The opening 527 is located below the inclined plate portion 521 and is covered by the projection of the inclined plate portion 521 onto the base plate 523. With this structure, both sufficient collection of liquid material and distillation of gaseous material can be ensured.

[0046] In some embodiments, the ratio of the diameter of the bottom plate 523 to the diameter of the cracking distillation column 5 can be set according to the amount of liquid material. Typically, the ratio of the diameter of the bottom plate 523 to the diameter of the cracking distillation column 5 is 0.6-0.8:1.

[0047] In some embodiments, the side outlet 530 is located on the side wall of the annular collection chamber of the cracking distillation column 5, particularly near the annular plate 525.

[0048] In some embodiments, a liquid-sealed pipeline is provided on the pipeline connecting the bottom inlet of the cracking distillation column 5 and the gas phase outlet of the cracking vessel 4. By providing the liquid-sealed pipeline, the non-crackable disilane that flows back from the cracking distillation column 5 to its bottom remains in the bottom and does not flow back to the cracking vessel 4, and is vaporized and separated again by the gas phase material from the gas phase outlet of the cracking vessel 4.

[0049] In some embodiments, the bottom of the cracking vessel 4 and the cracking distillation column 5 are provided with drain ports, and / or the bottom of the cracking distillation column 5 is provided with drain ports. This facilitates the discharge of materials from the bottom of the cracking vessel 4 and the cracking distillation column 5.

[0050] In some embodiments, various valves and / or pumps may be installed on each pipeline to enable the opening and closing of the pipeline and the conveying of materials within it.

[0051] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. Apparatus for the cleavage of disilanes to methylchlorosilanes, wherein, The apparatus includes a pyrolysis vessel (4), a pyrolysis distillation column (5), a cooler (8), and a reflux tank (9); characterized in that, The cracking vessel (4) is equipped with a disilane inlet, an HCl inlet, a catalyst inlet, and a gas phase outlet; The cracking distillation column (5) is provided with a bottom inlet, a top outlet, and a side-stream outlet (530). The bottom inlet of the cracking distillation column (5) is connected to the gas phase outlet of the cracking vessel (4) via a pipeline. The cracking distillation column (5) is provided with a packing layer (510) and a liquid collection structure located between the packing layer (510) and the bottom inlet. The liquid collection structure is connected to the side-stream outlet (530). The side-stream outlet (530) is connected to a side-stream outlet pipeline (6) for collecting liquid phase material. The cooler (8) is connected to the top outlet of the cracking distillation column (5) and is used to cool the crude product from the cracking distillation column (5); The inlet of the reflux tank (9) is connected to the cooler (8) for receiving and storing crude product from the cooler (8); the reflux tank (9) is provided with a discharge line (7) and a reflux line (10) for returning the crude product stored in the reflux tank (9) to the top of the cracking distillation column (5).

2. The apparatus for the cleavage of a disilane to methylchlorosilanes according to claim 1, characterized in that The liquid collection structure includes a liquid collection tank and a collection tray. The liquid collection tank includes a bottom plate (523), a guide plate, and a baffle (522). The size of the bottom plate (523) is smaller than the cross-sectional size of the cracking distillation column (5). The guide plate and the baffle (522) are installed on the bottom plate (523). The guide plate has an inclined plate portion (521) arranged obliquely upward from the center of the cracking distillation column (5). The baffle (522) is disposed adjacent to the inclined plate portion (521). The liquid collection tray includes a vertical plate (524) and an annular plate (525). The inner edge of the annular plate (525) is connected to the bottom plate (523) via the vertical plate (524), and the outer edge of the annular plate (525) is connected to the inner wall of the cracking distillation column (5), thereby forming an annular collection cavity. The groove (526) communicates with the annular collection cavity.

3. The apparatus for the cleavage of a disilane to methylchlorosilanes according to claim 2, characterized in that The angle between the inclined plate (521) and the vertical direction is 10-60°.

4. The apparatus for producing methylchlorosilane by disilane cracking according to claim 2, characterized in that, The angle between the inclined plate (521) and the vertical direction is 20-45°.

5. The apparatus for the cleavage of a disilane to methylchlorosilanes according to claim 2, characterized in that The base plate (523) is provided with an opening (527) for gaseous material to pass through. The opening (527) is located below the inclined plate (521) and is covered by the projection of the inclined plate (521) on the base plate (523).

6. The apparatus for the cleavage of a disilane to methylchlorosilanes according to claim 2, characterized in that The ratio of the diameter of the bottom plate (523) to the diameter of the cracking distillation column (5) is 0.6-0.8:

1.

7. The apparatus for the cleavage of a disilane to methylchlorosilanes according to claim 2, characterized in that The side outlet (530) is located on the side wall of the annular collection chamber of the cracking distillation column (5).

8. The apparatus for the cleavage of a disilane to methylchlorosilanes according to any one of claims 1 to 7, characterized in that A liquid seal pipeline is installed on the pipeline connecting the bottom inlet of the cracking distillation column (5) and the gas phase outlet of the cracking vessel (4).

9. The apparatus for the cleavage of a disilane to methylchlorosilanes according to any one of claims 1 to 7, characterized in that The bottom of the pyrolysis vessel (4) is provided with a drain port.

10. The apparatus for the cleavage of a disilane to methylchlorosilanes according to any one of claims 1 to 7, characterized in that The bottom of the cracking distillation column (5) is provided with a drain port.

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