Process method for direct delivery of chloromethane from crude monomer tower

Abstract

This invention discloses a process for directly feeding chloromethane from a crude monomer tower. The gaseous phase, primarily composed of chloromethane, is discharged from the top of the crude monomer tower via a top discharge pipe and processed in two separate paths: The first path is a direct feed path: the gaseous chloromethane is passed sequentially through a flow regulating valve and a flow meter for precise flow control before being directly fed to a chloromethane superheater for superheating and participation in the fluidized bed reaction. The second path is a reflux path: the gaseous chloromethane enters a condenser, and the condensed liquid enters a crude monomer reflux tank and is then returned to the crude monomer tower via a reflux pump. Compared to existing technologies, this invention avoids the multiple phase change processes of chloromethane first condensing and then vaporizing by directly feeding a portion of the gaseous chloromethane from the top of the tower to the superheater. This effectively reduces the consumption of steam and circulating water in the organosilicon monomer synthesis process while ensuring product quality.

Description

Technical Field

[0001] This invention relates to the field of organosilicon production technology, and in particular to a process method for directly feeding chloromethane from a crude monomer tower. Specifically, the process involves directly feeding the gaseous chloromethane from the top of the crude monomer tower to a chloromethane superheater for heating, and then directly participating in the organosilicon monomer synthesis reaction. Background Technology

[0002] In the monomer synthesis process of the organosilicon industry, the main function of the crude monomer tower is to purify the crude monomer. In the existing technology, the qualified material produced from the bottom of the crude monomer tower is sent to the next production process, while the light components at the top of the tower, mainly chloromethane, need to be condensed and recovered to the reflux tank via circulating water. Part of the material in the reflux tank is returned to the tower as reflux liquid to ensure the purification effect, and the other part is pumped to the chloromethane storage tank, and then pumped to the chloromethane vaporizer for re-vaporization before participating in the reaction in the fluidized bed.

[0003] In this process, chloromethane undergoes multiple phase changes (i.e., gas phase at the top of the tower → condensate phase → re-vaporization into gas phase in the vaporizer), resulting in unnecessary consumption of steam and circulating water, and increasing production costs. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a process for directly feeding chloromethane from a crude monomer tower, which effectively reduces the consumption of steam and circulating water in the organosilicon monomer synthesis process while ensuring product quality.

[0005] To achieve this technical objective, the present invention adopts the following scheme: a process method for directly feeding chloromethane from a crude monomer tower, wherein the gas phase with chloromethane as the main component at the top of the crude monomer tower is discharged from the top outlet pipe and divided into a first path and a second path for separate processing, specifically as follows: The first route is the direct route: gaseous chloromethane passes through a flow regulating valve and a flow meter to precisely control the flow rate, and is then directly sent to the chloromethane superheater for superheating before participating in the reaction in the fluidized bed; The second path is the reflux path: gaseous chloromethane enters the condenser, the condensed liquid enters the crude monomer reflux tank, and is then refluxed back to the crude monomer tower by the reflux pump.

[0006] Furthermore, the qualified material produced by the crude monomer tower is discharged from the bottom of the tower and sent to the next production process; the gas phase temperature at the top of the crude monomer tower, with chloromethane as the main component, is 30~50℃.

[0007] Furthermore, a check valve is installed on the first gas phase material conveying pipeline.

[0008] Furthermore, the inlet of the chloromethane superheater is connected to a chloromethane vaporizer, which is equipped with a liquid chloromethane inlet. The gaseous chloromethane from the first path merges with the gaseous chloromethane vaporized by the chloromethane vaporizer and enters the chloromethane superheater for superheating before participating in the subsequent fluidized bed reaction.

[0009] Furthermore, the condenser uses circulating water as the cooling medium and is equipped with a circulating water inlet, a circulating water outlet, and a non-condensable gas outlet.

[0010] Furthermore, the discharge temperature of the condenser is controlled at 32~43℃.

[0011] Furthermore, the pressure at the top of the crude monomer tower must be greater than the inlet pressure of the chloromethane superheater, with a pressure difference ≥ 10 kPa.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: Significantly reduced energy consumption: By directly sending a portion of the vaporous chloromethane from the top of the column to the superheater, the multiple phase change process of chloromethane first condensing and then vaporizing is avoided. Experimental data shows that directly sending 1 ton of chloromethane can reduce the average circulating water consumption by approximately 15m³. 3 / h, saving approximately 0.16t / h of steam.

[0013] Ensuring product quality: While significantly reducing energy consumption, this process can guarantee the quality of chloromethane. Data shows that after adopting this process, the average chloromethane content can reach 99.37%, meeting or even exceeding the level of the original process.

[0014] Process optimization and simple operation: The original process flow is simplified, the occupation and maintenance costs of equipment (such as storage tanks and transfer pumps) are reduced, the stability of system operation is improved, and the operation is flexible and stable through valve and flow meter control. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the process method for directly feeding chloromethane from a crude monomer tower in an embodiment of the present invention.

[0016] The following are marked in the diagram: 1. Crude monomer tower; 101. Bottom discharge pipe; 2. Flow regulating valve; 3. Flow meter; 4. Check valve; 5. Chloromethane superheater; 6. Chloromethane vaporizer; 601. Liquid chloromethane inlet; 7. Condenser; 701. Circulating water inlet; 702. Circulating water outlet; 703. Non-condensable gas outlet; 8. Crude monomer reflux tank; 9. Reflux pump; 10. Top discharge pipe; 11. First path; 12. Second path. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0018] Unless otherwise specified, the experimental methods used in the embodiments and comparative examples of this invention are conventional methods. Unless otherwise specified, the materials and reagents used are commercially available.

[0019] Please see Figure 1 This invention provides a process for directly feeding chloromethane from a crude monomer tower. The qualified material produced by crude monomer tower 1 is discharged from the bottom outlet pipe 101 and sent to the next production process. The gas phase (temperature 30-50℃) with chloromethane as the main component at the top of crude monomer tower 1 is discharged from the top outlet pipe 10. The gas phase chloromethane is divided into two streams (first stream 11 and second stream 12) for separate processing. The first route 11 is a direct delivery route: gaseous chloromethane passes through flow regulating valve 2, flow meter 3 and check valve 4 in sequence for precise flow control (e.g., controlling the direct delivery flow rate to 10~18 t / h), and then is directly sent to chloromethane superheater 5, where it merges with the gaseous chloromethane vaporized by chloromethane vaporizer 6 in the original system. After being superheated in chloromethane superheater 5, it participates in the reaction in the fluidized bed, avoiding the multiple phase changes of chloromethane (phase change process of condensation and revaporization). The second path, 12, is a reflux path: gaseous chloromethane enters condenser 7, where it is condensed using circulating water as the cooling medium, and the outlet temperature of condenser 7 is controlled at 32~43℃. The condensed liquid enters the crude monomer reflux tank 8 and is then returned to the crude monomer tower 1 via reflux pump 9, creating a stable concentration and temperature gradient within the crude monomer tower 1 to ensure its purification effect. Non-condensable gases are discharged from condenser 7 through non-condensable gas outlet 703, pass through the existing chloromethane buffer tank, and then enter the compressor.

[0020] Furthermore, to ensure the smooth operation of the direct delivery process, the pressure at the top of the crude monomer tower 1 must be greater than the inlet pressure of the chloromethane superheater 5, with a pressure difference preferably ≥10 kPa.

[0021] Furthermore, the chloromethane vaporizer 6 is provided with a liquid chloromethane inlet 601; the condenser 7 is provided with a circulating water inlet 701 and a circulating water outlet 702.

[0022] In one specific embodiment, the flow regulating valve 2 and the flow meter 3 are connected to the automatic control system to realize real-time dynamic control of the flow rate of the first direct-feed gaseous chloromethane 11.

[0023] In one specific embodiment, an online gas chromatograph is connected to the top discharge pipe 10 of the column to monitor the purity and impurity content of chloromethane in the top gas phase in real time, and feed the data back to the control system to automatically adjust the direct feed ratio to ensure the stable quality of chloromethane entering the fluidized bed.

[0024] In one specific embodiment, an emergency shut-off valve is provided on the first path 11, which can quickly cut off the direct delivery path under abnormal operating conditions to ensure system safety.

[0025] This invention adjusts the amount of gaseous chloromethane directly fed into the first channel 11 by adjusting the flow regulating valve 2, which can effectively reduce the amount of material entering the condenser 7, thereby reducing the consumption of circulating water; at the same time, since the amount of liquid feed entering the chloromethane vaporizer 6 is reduced, the amount of steam required for vaporization is also reduced accordingly. Examples 1-5

[0026] Using the process method of directly feeding chloromethane from the crude monomer tower of the present invention, the amount of gaseous chloromethane directly fed from the first channel 11 is adjusted by the flow regulating valve 2. Comparative Example 1

[0027] The original process method is adopted as follows: the gas phase at the top of the crude monomer tower is condensed by a condenser, and the condensate enters the crude monomer tower reflux tank. Part of it is forced to reflux by a reflux pump, and part of it is sent to the chloromethane circulation tank for recovery. After being mixed with fresh chloromethane, it is sent to the chloromethane vaporizer. After being vaporized by the chloromethane vaporizer, it enters the chloromethane superheater and participates in the fluidized bed reaction after being superheated.

[0028] The circulating water volume of the top condenser 7 of the crude monomer tower 1 and the steam consumption of the chloromethane vaporizer 6 were measured and statistically analyzed, and the specific results are shown in Table 1. The circulating water and steam consumption were calculated and compared, and the specific results are shown in Table 2. The savings in steam and circulating water consumption were compared with Comparative Example 1. The quality of chloromethane was tested, and the results are shown in Table 3. The three sets of data from Comparative Example 1 were sampled at 8-hour intervals.

[0029] Table 1. Statistics on the consumption of circulating water and steam in the process of this invention and the original process.

[0030] Table 2 Comparison of circulating water and steam consumption between the process of this invention and the original process

[0031] Table 3. Results of Chloromethane Quality Testing

[0032] The experimental data above show that the process method of this invention ensures the quality of chloromethane (content ≥99%). Based on the amount of directly fed gaseous chloromethane, the circulating water consumption of the condenser and the steam consumption of the chloromethane vaporizer in the original process can be effectively reduced. Effective experiments have shown that directly feeding 1 ton of chloromethane can reduce the circulating water consumption by an average of 15m³. 3 / h, steam 0.16t / h.

[0033] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; if these modifications and variations fall within the scope of the claims of the present invention and their equivalents, they should all be considered to be within the protection scope of the present invention.

Claims

1. A process for the direct chloromethane feed to a crude monomer column, characterized by, The gas phase, mainly composed of chloromethane, is discharged from the top of the crude monomer tower (1) through the top discharge pipe (10) and divided into a first path (11) and a second path (12) for separate processing, as follows: The first route (11) is a direct route: after the gaseous chloromethane passes through the flow regulating valve (2) and the flow meter (3) to precisely control the flow rate, it is directly sent to the chloromethane superheater (5) for superheating and then participates in the reaction in the fluidized bed. The second path (12) is the reflux path: gaseous chloromethane enters the condenser (7), and the condensed liquid enters the crude monomer reflux tank (8) and is refluxed back to the crude monomer tower (1) by the reflux pump (9).

2. The process for the direct feeding of chloromethane to a crude monomer column according to claim 1, characterized in that, The qualified material produced by the crude monomer tower (1) is discharged from the bottom discharge pipe (101) and sent to the next production process; the gas phase temperature of the top of the crude monomer tower (1), with chloromethane as the main component, is 30~50℃.

3. The process method for directly feeding chloromethane from a crude monomer tower according to claim 1, characterized in that, A check valve (4) is installed on the gas phase material conveying pipeline of the first route (11).

4. The process method for directly feeding chloromethane from a crude monomer tower according to claim 1, characterized in that, The inlet of the chloromethane superheater (5) is connected to the chloromethane vaporizer (6), and the chloromethane vaporizer (6) is provided with a liquid chloromethane inlet (601). The gaseous chloromethane from the first path (11) and the gaseous chloromethane vaporized by the chloromethane vaporizer (6) are combined and enter the chloromethane superheater (5) for superheating, and then participate in the subsequent fluidized bed reaction.

5. The process method for directly feeding chloromethane from a crude monomer tower according to claim 1, characterized in that, The condenser (7) uses circulating water as the cooling medium and is equipped with a circulating water inlet (701), a circulating water outlet (702), and a non-condensable gas outlet (703).

6. The process method for directly feeding chloromethane from a crude monomer tower according to claim 1, characterized in that, The discharge temperature of the condenser (7) is controlled at 32~43℃.

7. The process method for directly feeding chloromethane from a crude monomer tower according to claim 1, characterized in that, The pressure at the top of the crude monomer tower (1) must be greater than the inlet pressure of the chloromethane superheater (5), with a pressure difference ≥ 10 kPa.

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