A separation system for methyl chlorosilane monomers

Abstract

The application discloses a separation system of methyl chlorosilane monomer, which comprises a low-removal column overhead compressor and a binary column overhead compressor. The overhead gas phase of the low-removal column is pressurized and heated by the low-removal column overhead compressor, and then the pressurized and heated gas phase is respectively delivered to a light separation column bottom reboiler, a hydrogen-containing column bottom reboiler, a azeotrope column bottom reboiler and a trimethyl column bottom reboiler through pipelines to provide the required heat source. The overhead gas phase of the binary column is pressurized and heated by the binary column overhead compressor, and then delivered to a binary column bottom reboiler to provide the heat source for the binary column bottom reboiler. The low-removal column overhead compressor, the low-removal column, the light separation column bottom reboiler, the hydrogen-containing column bottom reboiler, the azeotrope column bottom reboiler, the trimethyl column bottom reboiler, the binary column overhead compressor, the binary column and the binary column bottom reboiler constitute a heat pump circulation system, and the operation of the whole separation system of the methyl chlorosilane monomer reduces the consumption of external steam.

Description

Technical Field

[0001] This invention relates to the field of organosilicon monomer distillation technology, and more particularly to a separation system for methylchlorosilane monomers. Background Technology

[0002] Dimethyldichlorosilane (hereinafter referred to as dimethyl) is the methylchlorosilane monomer with the largest demand in the organosilicon industry. Currently, it is mainly synthesized industrially through direct synthesis from silicon powder and chloromethane in the presence of a copper catalyst. This method yields multi-component mixtures including dimethyl, such as monomethyltrichlorosilane (hereinafter referred to as monomethyl), trimethylchlorosilane (hereinafter referred to as trimethyl), monomethyldichlorosilane (hereinafter referred to as monomethylhydrogen), and dimethylchlorosilane (hereinafter referred to as dimethylhydrogen). Currently, distillation is commonly used in industry for the separation and purification of dimethyl. However, because the boiling point difference between monomethyl and dimethyl is approximately 3.8°C, it is necessary to increase the number of distillation trays and the reflux ratio of the distillation column to achieve a dimethyl purity greater than 99.8%. Therefore, the equipment investment and operating energy consumption of the distillation column account for a significant proportion of the organosilicon production cost.

[0003] Current industrial distillation processes are mainly classified into three types: cis-cut, anti-cut, and mid-section cut. Among them, anti-cut and mid-section cut processes are difficult to operate, and the purity of dimethyl methacrylate (DMMA) is unstable. Therefore, the cis-cut process is mainly used in industry. Common cis-cut processes include seven-tower and eight-tower processes. In the seven-tower process, DMMA and DMMA are separated in a binary column, requiring high separation standards and a completely linear process with low product recovery. The eight-tower process adds a circulating stream, but DMMA and DMMA are still separated in a binary column. It requires a high number of trays and a large operating reflux ratio, but all of these processes generally suffer from high energy consumption.

[0004] Therefore, how to reduce operating energy consumption is a technical problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the object of the present invention is to provide a separation system for methylchlorosilane monomers to reduce operating energy consumption.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A separation system for methylchlorosilane monomers includes a high-density removal tower, a low-density removal tower, a binary tower, a monomethyl silane purification tower, a light fractionation tower, a hydrogen-containing tower, an azeotropic tower, a trimethyl silane tower, a reboiler for the high-density removal tower, a reboiler for the low-density removal tower, a reboiler for the binary tower, a reboiler for the monomethyl silane purification tower, a reboiler for the light fractionation tower, a reboiler for the hydrogen-containing tower, a reboiler for the azeotropic tower, and a reboiler for the trimethyl silane tower. The system is characterized by further including a compressor at the top of the low-density removal tower and a compressor at the top of the binary tower.

[0008] The inlet of the compressor at the top of the de-oxidation tower is connected to the gas phase outlet at the top of the de-oxidation tower, and the outlet of the compressor at the top of the de-oxidation tower is connected to the hot-side inlet of the reboiler at the bottom of the light fractionation tower, the hot-side inlet of the reboiler at the bottom of the hydrogen-containing tower, the hot-side inlet of the reboiler at the bottom of the azeotropic tower, and the hot-side inlet of the reboiler at the bottom of the trimethylolpropionate tower via pipelines. The reflux liquid inlet at the top of the de-oxidation tower is connected to the hot-side outlet of the reboiler at the bottom of the light fractionation tower, the hot-side outlet of the reboiler at the bottom of the hydrogen-containing tower, the hot-side outlet of the reboiler at the bottom of the azeotropic tower, and the hot-side outlet of the reboiler at the bottom of the trimethylolpropionate tower via pipelines.

[0009] The inlet of the top compressor of the binary column is connected to the top gas phase outlet of the binary column, the outlet of the top compressor of the binary column is connected to the hot side inlet of the reboiler of the binary column, and the hot side outlet of the reboiler of the binary column is connected to the top reflux liquid inlet of the binary column through a pipeline.

[0010] Optionally, the separation system for the methylchlorosilane monomers described above also includes a cracking tower and a disproportionation tower. The cracking tower is used to recover crude monomers from the product of the high-boiling cracking unit, and the disproportionation tower is used to recover crude monomers from the product of the low-boiling disproportionation unit. The cracking tower, the disproportionation tower, and the high-boiling removal tower are connected in sequence via pipelines.

[0011] Optionally, in the above-mentioned separation system for methylchlorosilane monomers, the outlet of the compressor at the top of the de-lowering column is connected to the hot-side inlet of the reboiler at the bottom of the disproportionating column via a pipeline, and the hot-side outlet of the reboiler at the bottom of the disproportionating column is connected to the reflux inlet at the top of the de-lowering column.

[0012] Optionally, the separation system for the methylchlorosilane monomer described above also includes a low-boiling tower, which is connected to the light fractionation tower via a pipeline for extracting the dimethyl hydrogen-containing product and tetramethyl product from the low-boiling product produced by the light fractionation tower. The outlet of the compressor at the top of the low-boiling tower is connected to the hot-side inlet of the reboiler at the bottom of the low-boiling tower via a pipeline, and the hot-side outlet of the reboiler at the bottom of the low-boiling tower is connected to the reflux inlet at the top of the low-boiling tower via a pipeline.

[0013] Optionally, in the separation system of the methylchlorosilane monomer described above, a portion of the product collected from the top of the binary column is sent to the monomethyl purification column, and another portion is sent to the low-boiling disproportionation unit, with the product sent to the monomethyl purification column accounting for 1 / 3 to 1 / 3 of the total product.

[0014] Optionally, in the above-mentioned separation system for methylchlorosilane monomers, the gas phase outlet at the top of the de-elution column is connected to the hot-side inlet of the reboiler at the bottom of the de-elution column, and the hot-side outlet of the reboiler at the bottom of the de-elution column is connected to the reflux liquid inlet at the top of the de-elution column.

[0015] Optionally, in the above-mentioned separation system for methylchlorosilane monomers, the temperature of the gas phase at the top of the depressurization tower after being pressurized by the compressor at the top of the depressurization tower should not be less than 100-130°C.

[0016] Optionally, in the above-mentioned separation system for methylchlorosilane monomers, the temperature difference between the temperature of the gas phase at the top of the binary column after being pressurized by the compressor at the top of the binary column and the temperature of the bottom of the binary column should be no less than 5 to 25°C.

[0017] Optionally, in the above-mentioned separation system for methylchlorosilane monomers, the compression ratio of the compressor at the top of the de-lowering column and the compressor at the top of the binary column ranges from 1.5 to 5.

[0018] Optionally, in the above-mentioned separation system for methylchlorosilane monomers, the diameter of the monomethyl purification tower is set to 2 / 3 of the diameter of the binary tower.

[0019] This invention provides a separation system for methylchlorosilane monomers. After pressurizing and heating the overhead gas phase of the de-oxidation column using a compressor at the top of the column, the pressurized and heated gas phase is then piped to the reboilers of the light fractionation column, hydrogen-containing column, azeotropic column, and trimethylsilane column, providing them with the necessary heat source. Furthermore, the reboilers of the light fractionation column, hydrogen-containing column, azeotropic column, and trimethylsilane column are all connected to the reflux inlet at the top of the de-oxidation column via pipelines, allowing the condensed liquid to flow back into the de-oxidation column. A binary column overhead compressor is also provided. This compressor pressurizes and heats the overhead gas phase of the binary column and then pipes it to the reboiler at the bottom of the binary column, providing a heat source for the reboiler. The condensed liquid then returns to the binary column through the reflux inlet. Thus, the compressor at the top of the de-oxidation tower and the reboiler at the bottom of the de-oxidation tower, the reboiler at the bottom of the light separation tower, the reboiler at the bottom of the hydrogen-containing tower, the reboiler at the bottom of the azeotropic tower, the reboiler at the bottom of the trimethylolpropionate tower, and the compressor at the top of the binary tower and the reboilers at the bottom of the binary tower constitute a circulating system, reducing the external heat consumption of each tower reboiler, and thus reducing the steam consumption of the entire methylchlorosilane monomer separation system. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the separation system for methylchlorosilane monomers disclosed in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the structure of a separation system for methylchlorosilane monomers disclosed in another embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the separation system for methylchlorosilane monomers disclosed in another embodiment of the present invention.

[0024] Among them, 1 is the high-boiling point removal tower, 2 is the low-boiling point removal tower, 3 is the binary tower, 4 is the monomethyl purification tower, 5 is the light fractionation tower, 6 is the hydrogen-containing tower, 7 is the azeotropic tower, 8 is the trimethylolpropane tower, 9 is the cracking tower, 10 is the disproportionation tower, 11 is the low-boiling point tower, 12 is the reboiler at the bottom of the high-boiling point removal tower, 13 is the reboiler at the bottom of the low-boiling point removal tower, 14 is the reboiler at the bottom of the binary tower, 15 is the reboiler at the bottom of the monomethyl purification tower, 16 is the condenser at the top of the monomethyl purification tower, 17 is the reboiler at the bottom of the light fractionation tower, 18 is the condenser at the top of the light fractionation tower, and 19 is the reboiler at the bottom of the hydrogen-containing tower. 20 is the condenser at the top of the hydrogen-containing column, 21 is the reboiler at the bottom of the azeotropic column, 22 is the condenser at the top of the azeotropic column, 23 is the reboiler at the bottom of the trimethylolpropionate column, 24 is the condenser at the top of the trimethylolpropionate column, 25 is the reboiler at the bottom of the cracking column, 26 is the condenser at the top of the cracking column, 27 is the reboiler at the bottom of the disproportionation column, 28 is the condenser at the top of the disproportionation column, 29 is the reboiler at the bottom of the low-boiling-point column, 30 is the condenser at the top of the low-boiling-point column, 31 is the steam reboiler of the binary column, 32 is the compressor at the top of the low-boiling-point column, and 33 is the compressor at the top of the binary column. Detailed Implementation

[0025] The purpose of this invention is to provide a separation system for methylchlorosilane monomers to reduce operating energy consumption.

[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figure 1As shown in the figure, an embodiment of the present invention discloses a separation system for methylchlorosilane monomers, including a high-density removal tower 1, a low-density removal tower 2, a binary tower 3, a monomethyl silane purification tower 4, a light fractionation tower 5, a hydrogen-containing tower 6, an azeotropic tower 7, a trimethyl silane tower 8, a high-density removal tower reboiler 12, a low-density removal tower reboiler 13, a binary tower reboiler 14, a monomethyl silane purification tower reboiler 15, a light fractionation tower reboiler 17, a hydrogen-containing tower reboiler 19, an azeotropic tower reboiler 21, a trimethyl silane tower reboiler 23, a monomethyl silane purification tower top condenser 16, a light fractionation tower top condenser 18, a hydrogen-containing tower top condenser 20, an azeotropic tower top condenser 22, a trimethyl silane tower top condenser 24, a binary tower vapor reboiler 31, a low-density removal tower top compressor 32, and a binary tower top compressor 33, all connected by pipelines.

[0028] The inlet of the compressor 32 at the top of the deionization tower is connected to the gas phase outlet at the top of the deionization tower 2, allowing the gas phase at the top of the deionization tower 2 to enter the compressor 32 for pressurization and heating. The outlet of the compressor 32 is connected to the inlet of the distribution manifold, allowing the pressurized and heated gas phase at the top of the deionization tower 2 to enter the distribution manifold. Then, through the outlets of the various branches of the distribution manifold, the gas phase enters the reboiler 19 of the hydrogen-containing tower, the reboiler 21 of the azeotropic tower, the reboiler 23 of the trimethylolpropionate tower, and the reboiler 17 of the light fractionation tower, respectively, providing a heat source for the operation of each reboiler. The condensate formed by the condensation of the gas phase in each reboiler is then returned to the deionization tower 2 through pipelines. Similarly, the top compressor 33 of the binary column pressurizes and heats the top gas phase of the binary column 3 and then delivers it to the reboiler 14 of the binary column, providing a heat source for the reboiler 14. The condensate from the reboiler 14 is then returned to the binary column 3 through pipelines. The methylchlorosilane monomer separation system provided in this embodiment recovers and reuses the top gas phases of the de-lowering column 2 and the binary column 3 through the top compressor 32 of the de-lowering column and the top compressor 33 of the binary column, reducing the overall heat energy consumption of the operation.

[0029] like Figure 2As shown, the methylchlorosilane monomer separation system provided in this embodiment also includes a cracking tower 9, a cracking tower reboiler 25, a cracking tower top condenser 26, a disproportionation tower 10, a disproportionation tower reboiler 27, and a disproportionation tower top condenser 28. The crude monomer from the high-boiling-point cracking unit enters the cracking tower 9 for processing. The vapor phase at the top of the cracking tower 9 is completely condensed into liquid in the cracking tower top condenser 26. A portion of this liquid is refluxed back into the cracking tower 9, while the other portion, as a product, is mixed with the disproportionation monomer feedstock and then enters the disproportionation tower 10. The bottom product of the cracking tower 9 is collected as a non-crackable high-boiling-point substance and sent out of the boundary area. The raw crude monomer is mixed with the product from the bottom of disproportionation tower 10 and then fed into the high-boiling-point tower 1. The high-boiling-point product collected from the bottom of disproportionation tower 10 is sent out of the boundary area. The vapor phase at the top of the high-boiling-point tower 1 is completely condensed into liquid by the reboiler 13 at the bottom of the low-boiling-point tower. A portion of this liquid is refluxed back into the high-boiling-point tower 1 through a pipeline, while the other portion is sent as product to the low-boiling-point tower 2 for further processing. Therefore, the newly added cracking tower 9 and disproportionation tower 10 recover crude monomers such as dimethyl from the products of the high-boiling-point cracking unit and the low-boiling-point disproportionation unit, respectively, thereby improving the yield of dimethyl.

[0030] Furthermore, the outlet of the compressor 32 at the top of the descaling tower is connected to the hot side inlet of the reboiler 27 at the bottom of the disproportionation tower 10 via a distribution manifold. The hot side outlet of the reboiler 27 at the bottom of the disproportionation tower is connected to the reflux liquid inlet at the top of the descaling tower 2 via a pipeline. The compressor 32 at the top of the descaling tower inputs the gas phase at the top of the descaling tower 2 to the reboiler 27 at the bottom of the disproportionation tower to provide it with a heat source, thereby realizing the recycling of internal heat energy and further reducing the consumption of external steam.

[0031] like Figure 3 As shown, the separation system for methylchlorosilane monomers provided in this embodiment also includes a low-boiling tower 11. The low-boiling tower 11 is connected to the light separation tower 5 through a pipeline. After the gas phase at the top of the light separation tower 5 is completely condensed into liquid in the condenser 18 at the top of the light separation tower, a portion of it flows back into the light separation tower 5 through reflux, while the other portion enters the low-boiling tower 11 as a product to purify and extract the dimethyl hydrogen and tetramethyl from the low-boiling product produced by the light separation tower 5, thereby improving the quality of the product. The dimethyl hydrogen is extracted from the top of the tower and transported to the storage tank area, while the tetramethyl product is extracted from the side stream and transported to the storage tank area. Similarly, the compressor 32 at the top of the de-boiling tower pressurizes and heats the gas phase at the top of the de-boiling tower 2 and then delivers it to the reboiler 29 at the bottom of the low-boiling tower 11 to provide a heat source. The hot side outlet of the reboiler 29 is connected to the reflux liquid inlet at the top of the de-boiling tower 2 through a pipeline, so that the condensed liquid flows back to the de-boiling tower 2.

[0032] In one specific embodiment, considering that the downstream low-boiling disproportionation unit does not have high purity requirements for the methylchlorosilane raw material, a portion of the product collected from the top of the binary tower 3 provided in this embodiment is sent to the methylchlorosilane purification tower 4, while the other portion, as crude methylchlorosilane product, is sent to the low-boiling disproportionation unit. The product sent to the methylchlorosilane purification tower 4 accounts for 1 / 3 to 1 / 4 of the total product. Compared with the prior art where the methylchlorosilane product is completely purified before being sent to downstream units, the methylchlorosilane monomer separation system provided in this embodiment reduces the energy consumption required for methylchlorosilane purification, further reducing the overall operating energy consumption.

[0033] Furthermore, the top vapor outlet of the high-pressure stripping column 1 is connected to the hot-side inlet of the reboiler 13 of the low-pressure stripping column. By increasing the pressure of the high-pressure stripping column 1, the temperature of the top vapor in the high-pressure stripping column 1 is raised to heat the reboiler 13 of the low-pressure stripping column, thereby reducing steam consumption. The hot-side outlet of the reboiler 13 of the low-pressure stripping column is connected to the top reflux liquid inlet of the high-pressure stripping column 1, allowing the condensed liquid to flow back into the high-pressure stripping column 1 through a pipeline. In a specific embodiment, the top temperature of the high-pressure stripping column 1 is 118°C, and the bottom temperature of the low-pressure stripping column 2 is 98°C, with a temperature difference of 20°C.

[0034] To ensure that the overhead gas phase of the depressurization tower 2 provides sufficient heat energy for the reboilers after being pressurized by the overhead compressor 32, the temperature of the overhead gas phase of the depressurization tower 2 after being pressurized by the overhead compressor 32 should be no less than 100-130°C. In a specific embodiment, the outlet gas temperature of the overhead compressor 32 is 117°C. The temperature difference between the overhead gas phase of the binary column 3 after being pressurized by the binary compressor 33 and the reboiler temperature of the binary column 3 should be no less than 5-25°C. In a specific embodiment, the outlet gas temperature of the binary compressor 33 is 113°C, and the reboiler temperature of the binary column 3 is 98°C, with a temperature difference of 15°C. The compression ratios of the overhead compressor 32 and the binary compressor 33 range from 1.5 to 5. In a specific embodiment, the compression ratio of the overhead compressor 32 is 3, and the compression ratio of the binary compressor 33 is 2.5. By setting the parameters as described above, the stability of the methylchlorosilane monomer separation system provided in this embodiment is ensured, while the energy consumption of the entire system is kept low.

[0035] In another specific embodiment, the methylchlorosilane monomer separation system provided in this embodiment splits the binary tower used in the conventional process for separating monomethyl and dimethyl silane into a binary tower 3 and a monomethyl silane purification tower 4. The total height of the two towers after splitting is the same as that of the binary tower in the prior art. However, the diameter of the monomethyl silane purification tower 4 provided in this embodiment is only 2 / 3 of the diameter of the binary tower 3 (the monomethyl silane product yield and purity requirements are kept consistent), thereby reducing the overall investment cost.

[0036] In summary, the specific operating steps of the methylchlorosilane monomer separation system provided in this embodiment are as follows:

[0037] 1. After the raw material crude monomer is mixed with the product from the bottom of the disproportionation tower 10, it enters the high-boiling product tower 1. The high-boiling product is collected from the bottom of the tower and sent out of the boundary area. The gas phase at the top of the high-boiling product tower 1 is completely condensed into liquid by the reboiler 13 at the bottom of the low-boiling product tower. Part of it flows back into the high-boiling product tower 1, and the other part enters the low-boiling product tower 2 for further processing.

[0038] 2. The gas phase at the top of the depressurization tower 2 is pressurized by the compressor 32 at the top of the depressurization tower. After pressurization, the gas phase flows through the distribution manifold into the reboilers 17, 19, 21, 23, 27, and 29 of the light fractionation tower, hydrogen-containing tower, azeotropic tower, trimethylolpropane tower, disproportionation tower, and low-boiling tower, providing heat energy. After being completely condensed into liquid, part of the liquid flows back to the depressurization tower 2 through the pipeline, while the other part is mixed with the top product of the disproportionation tower 10 and the bottom product of the low-boiling tower 11 and then enters the light fractionation tower 5. The bottom product of the light fractionation tower 5 is mixed with the bottom product of the monomethylolpropane purification tower 4 and then sent to the binary tower 3 for processing.

[0039] 3. The vapor phase at the top of the binary tower 3 enters the binary tower top compressor 33 for pressurization. After pressurization, the vapor phase provides heat energy to the reboiler 14 at the bottom of the binary tower. After being completely condensed into liquid, it is divided into three parts for processing. The first part flows back to the binary tower 3 through pipelines. The second part is collected as a product and sent to the monomethyl purification tower 4 for processing and purification. The third part is sent out of the boundary area as crude monomethyl product. The dimethyl product collected from the bottom of the binary tower 3 is sent to the storage tank area.

[0040] 4. After the vapor phase at the top of the monomethyl purification tower 4 is completely condensed into liquid in the top condenser 16 of the monomethyl purification tower, part of the liquid flows back into the monomethyl purification tower 4, and the other part is sent to the storage tank area as monomethyl product. The product taken from the bottom of the monomethyl purification tower 4 is recycled back to the binary tower 3.

[0041] 5. After the gas phase at the top of the light separation column 5 is completely condensed into liquid in the light separation column top condenser 18, part of it is returned to the light separation column 5, and the rest is sent to the low boiling column 11 as product; the product taken from the bottom of the light separation column 5 flows into the hydrogen-containing column 6.

[0042] 6. After the gas phase at the top of the hydrogen-containing tower 6 is completely condensed into liquid in the condenser 20 at the top of the hydrogen-containing tower, part of it flows back to the hydrogen-containing tower 6, and the other part is sent to the storage tank area or the discharge area as a hydrogen-containing product. The product taken out from the bottom of the hydrogen-containing tower 6 flows into the azeotropic tower 7.

[0043] 7. After the vapor phase at the top of the azeotropic tower 7 is completely condensed into liquid in the condenser 22 at the top of the azeotropic tower, part of it flows back into the azeotropic tower 7, and the other part is sent to the storage tank area or the discharge area as azeotropic product. The product taken out from the bottom of the azeotropic tower 7 flows into the tertiary azeotropic tower 8.

[0044] 8. After the vapor phase at the top of the methyl methacrylate tower 8 is completely condensed into liquid in the condenser 24 at the top of the methyl methacrylate tower, part of it is returned to the methyl methacrylate tower 8, and the remainder is sent to the storage tank area as methyl methacrylate product; the bottom of the methyl methacrylate tower 8 is recycled back to the crude monomer tank area or sent out of the boundary area.

[0045] 9. The cracked monomer feedstock enters cracking tower 9. The gas phase at the top of cracking tower 9 is completely condensed into liquid in the top condenser 26 of cracking tower. A portion of it is returned to cracking tower 9, and the remaining portion is mixed with disproportionated monomer feedstock and enters disproportionation tower 10. The bottom of cracking tower 9 is collected as non-crackable high-boiling-point material and sent out of the boundary area.

[0046] 10. The vapor phase at the top of the disproportionation tower 10 is completely condensed into liquid in the top condenser 28 of the disproportionation tower. Part of it is returned to the disproportionation tower 10, and the remainder enters the light separation tower 5. The bottom product of the disproportionation tower 10 enters the de-elution tower 1.

[0047] 11. After the gas phase at the top of the low-boiling tower 11 is completely condensed into liquid in the condenser 30 at the top of the low-boiling tower, part of it is returned to the low-boiling tower 11, and part of it is collected from the top of the tower as dimethyl hydrogen-containing product and sent to the storage tank area. At the same time, the low-boiling tower is equipped with a side sampling port to collect tetramethyl product and send it to the storage tank area, while the bottom product of the low-boiling tower 11 is recycled back to the light separation tower 5.

[0048] Table 1 compares the external energy consumption required by the methylchlorosilane monomer separation system provided in this embodiment and the prior art when processing the same amount of material and meeting product requirements, using conventional processes.

[0049] Table 1: Energy Consumption Comparison Results

[0050] Energy consumption of existing technologies Energy consumption of this embodiment De-oiling tower reboiler 7146.4kW 7146.4kW De-boiler 5325.5kW / Binary column reboiler 13299.3kW 2671.0kW Ammonia purification tower reboiler 2158.7kW 1439.1kW Light fractionation column reboiler 661.5kW / Hydrogen-containing column reboiler 431.4kW / Azeotropic column reboiler 434.7kW / Trimethoate reboiler 693.9kW / pyrolysis tower reboiler 328.6kW 328.6kW Disproportionation tower reboiler 670.9kW / Low-boiling column reboiler 288.7kW / Light tower top compressor / 787.6kW Binary tower top compressor / 1068.5kW

[0051] The comparative data above shows that, using the method of this invention, under the same processing volume and product purity requirements, the heat consumption is only 43% of that of existing industrial processes, resulting in energy savings of approximately 57%, and significantly reducing steam consumption.

[0052] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0053] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "a," and / or "the" are not specifically singular and may include the plural. Generally, the terms "comprising" and "including" only indicate the inclusion of expressly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements. An element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, product, or apparatus that includes the element.

[0054] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature.

[0055] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A separation system of methyl chlorosilane monomers comprising a high-removing column (1), a low-removing column (2), a binary column (3), a monomethyl purifying column (4), a light separation column (5), a hydrogen-containing column (6), a azeotrope column (7), a trimethyl column (8), a high-removing column reboiler (12), a low-removing column reboiler (13), a binary column reboiler (14), a monomethyl purifying column reboiler (15), a light separation column reboiler (17), a hydrogen-containing column reboiler (19), a azeotrope column reboiler (21) and a trimethyl column reboiler (23), characterized in that: The low-removing column overhead compressor (32) and the binary column overhead compressor (33) are further included. The inlet of the low-removing column overhead compressor (32) is communicated with the overhead gas phase outlet of the low-removing column (2), and the outlet of the low-removing column overhead compressor (32) is communicated with the hot side inlet of the light separation column bottom reboiler (17), the hot side inlet of the hydrogen-containing column bottom reboiler (19), the hot side inlet of the azeotrope column bottom reboiler (21), and the hot side inlet of the trimethyl column bottom reboiler (23) through pipelines, and the overhead reflux liquid inlet of the low-removing column (2) is communicated with the hot side outlet of the light separation column bottom reboiler (17), the hot side outlet of the hydrogen-containing column bottom reboiler (19), the hot side outlet of the azeotrope column bottom reboiler (21), and the hot side outlet of the trimethyl column bottom reboiler (23) through pipelines. The inlet of the binary column overhead compressor (33) is communicated with the overhead gas phase outlet of the binary column (3), the outlet of the binary column overhead compressor (33) is communicated with the hot side inlet of the binary column bottom reboiler (14), and the hot side outlet of the binary column bottom reboiler (14) is communicated with the overhead reflux liquid inlet of the binary column (3) through a pipeline.

2. The separation system of methylchlorosilane monomers according to claim 1, characterized in that, The cracking column (9) for recovering crude monomers in high-boiling cracking device products and the disproportionation column (10) for recovering crude monomers in low-boiling disproportionation device products are further included, and the cracking column (9), the disproportionation column (10), and the high-removing column (1) are sequentially communicated through pipelines.

3. The separation system of methylchlorosilane monomers of claim 2, wherein, The outlet of the low-removing column overhead compressor (32) is communicated with the hot side inlet of the disproportionation column bottom reboiler (27) of the disproportionation column (10) through a pipeline, and the hot side outlet of the disproportionation column bottom reboiler (27) is communicated with the overhead reflux liquid inlet of the low-removing column (2).

4. The separation system of methylchlorosilane monomers of claim 1, wherein, The low-boiling column (11) is further included, which is communicated with the light separation column (5) through a pipeline for recovering dimethyl hydrogen-containing products and tetramethyl products in low-boiling products produced by the light separation column (5), and the outlet of the low-removing column overhead compressor (32) is communicated with the hot side inlet of the low-boiling column bottom reboiler (29) of the low-boiling column (11) through a pipeline, and the hot side outlet of the low-boiling column bottom reboiler (29) is communicated with the overhead reflux liquid inlet of the low-removing column (2) through a pipeline.

5. The separation system of methylchlorosilane monomers of claim 1, wherein, Part of the products taken from the top of the binary column (3) is transported to the monomethyl purification column (4), and the other part is sent to the low-boiling disproportionation device, and the products transported to the monomethyl purification column (4) account for 1 / 3-1 of the total products.

6. The separation system of methylchlorosilane monomers of claim 1, wherein, The overhead gas phase outlet of the high-removing column (1) is communicated with the hot side inlet of the low-removing column bottom reboiler (13), and the hot side outlet of the low-removing column bottom reboiler (13) is communicated with the overhead reflux liquid inlet of the high-removing column (1).

7. The separation system of methylchlorosilane monomers of claim 1, wherein, The temperature of the overhead gas phase of the low-removing column (2) after being pressurized by the low-removing column overhead compressor (32) should be not less than 100-130℃.

8. The separation system of methylchlorosilane monomers of claim 1, wherein, The temperature difference between the temperature of the overhead gas phase of the binary column (3) after being pressurized by the binary column overhead compressor (33) and the temperature of the column bottom of the binary column (3) should be not less than 5-25℃.

9. The separation system of methylchlorosilane monomers of claim 1, wherein, The compression ratio of the low-boiling column overhead compressor (32) and the binary column overhead compressor (33) ranges from 1.5 to 5.

10. The separation system of methylchlorosilane monomers of claim 1, wherein, The diameter of the monomethyl purification column (4) is set to 2 / 3 of the diameter of the binary column (3).

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