Continuous production system for low-viscosity dimethyl silicone oil

Abstract

The utility model discloses a low-viscosity dimethyl silicone oil continuous production system which comprises a batching device and a purification device and further comprises a sectional type fixed bed device arranged between the batching device and the purification device, the sectional type fixed bed device comprises at least two fixed beds, and materials are suitable for entering the fixed beds after being evenly stirred in the batching device. A dimethyl silicone oil crude product is prepared through a catalytic reaction, and then the low-viscosity dimethyl silicone oil is prepared through a purification device. According to the continuous production system for the low-viscosity dimethyl silicone oil, multiple catalytic reactions can be realized, and the experimental yield of the low-viscosity dimethyl silicone oil and the stability of the product are effectively improved.

Description

Technical Field

[0001] This application relates to the field of chemical technology, and in particular to a continuous production system for low-viscosity dimethyl silicone oil. Background Technology

[0002] Dimethyl silicone oil possesses characteristics such as heat resistance, cold resistance, minimal viscosity change with temperature, water resistance, low surface tension, and thermal conductivity. It is widely used in moisture-proofing, insulation, damping, shock absorption, defoaming, lubrication, and polishing, serving as an insulating lubricant, shock absorber, oil and dust protectant, dielectric fluid, and heat transfer medium. It is also used as a defoamer, mold release agent, paint, and additive in daily chemical products, resulting in significant market demand.

[0003] The main method for synthesizing low-viscosity dimethyl silicone oil is to obtain it by catalytic reaction of a mixture of D4 (octamethylcyclotetrasiloxane) and MM (hexamethyldisiloxane) at a specific temperature.

[0004] Currently, application publication number CN 113941167 A discloses a production equipment and method for dimethyl silicone oil, which uses a powdered catalyst. Subsequent filtration is complex, and powder residue easily remains in the product, leading to a decline in product quality. Application publication number CN 110818900A discloses a method and production system for the continuous catalytic synthesis and separation of high-purity, low-viscosity dimethyl silicone oil, employing a fixed-bed device to achieve continuous production of dimethyl silicone oil. However, this method has a low yield, and the product stability significantly decreases with catalyst deactivation. Therefore, it is necessary to invent a novel dimethyl silicone oil production system to solve the problems of declining product quality and stability. Summary of the Invention

[0005] One objective of this application is to improve the experimental yield and product stability of dimethyl silicone oil.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: a continuous production system for low-viscosity dimethyl silicone oil, including a batching device and a purification device, and further including a segmented fixed bed device disposed between the batching device and the purification device. The segmented fixed bed device includes at least two fixed beds. The material is suitable for being stirred evenly in the batching device and then entering the fixed bed, where it undergoes a catalytic reaction to obtain crude dimethyl silicone oil, which is then purified by the purification device to obtain low-viscosity dimethyl silicone oil.

[0007] As a preferred embodiment, the fixed beds are connected in series, so that the material undergoes a catalytic reaction once as it passes through each fixed bed, thereby improving the material reaction efficiency.

[0008] As a preferred embodiment, the fixed beds are connected sequentially from bottom to top, which facilitates continuous production, reduces downtime caused by material transfer, and improves production efficiency.

[0009] As a preferred embodiment, the packing material in each of the fixed beds includes a catalyst and glass beads. That is, the remaining space in the fixed bed after the catalyst is filled is filled with glass beads. The glass beads can not only support the catalyst and disperse the material, but also prevent the catalyst from being lost and reduce the pressure generated by the material flow in the fixed bed.

[0010] As a preferred embodiment, the catalyst dosage in each of the fixed beds is the same to ensure that the reaction conditions in each fixed bed are consistent and to improve the catalytic efficiency of the material.

[0011] As a preferred option, the filling material in the fixed bed can also be inert alumina balls, ceramics, or quartz sand.

[0012] As a preferred embodiment, the segmented fixed-bed apparatus further includes a crude product tank suitable for buffering the crude dimethyl silicone oil product obtained after the fixed-bed catalytic reaction.

[0013] As a preferred embodiment, the batching device includes a material tank, a batching vessel, and an intermediate tank arranged in sequence. The material tank conveys material into the batching vessel, and after the material is mixed evenly in the batching vessel, it is transported to the intermediate tank for buffering by a pump. The material mixture in the intermediate tank is filtered by a filter and then transported to each of the fixed beds by a pump for catalytic reaction.

[0014] As a preferred embodiment, the purification apparatus includes a descaling tower and a product tank arranged in sequence. The descaling tower is suitable for purifying crude dimethyl silicone oil delivered by a pump, and the product tank is suitable for storing low-viscosity dimethyl silicone oil after purification by the descaling tower and filtration by a filter.

[0015] Compared with the prior art, the beneficial effects of this application are as follows:

[0016] (1) This application adopts a segmented fixed bed device, in which the catalyst is evenly distributed in multiple fixed beds connected in series. Compared with a single fixed bed with the same amount of catalyst, the material can achieve multiple catalytic reactions under the condition that the residence time remains unchanged, which effectively improves the experimental yield and product stability.

[0017] (2) This application uses a segmented fixed bed device, in which the catalyst is evenly distributed in multiple fixed beds connected in series. Compared with a single fixed bed device, even if the catalyst in one of the fixed beds of this application is deactivated, the remaining fixed beds can still carry out the catalytic reaction, ensuring the output of the product and the stability of the production system. Attached Figure Description

[0018] Figure 1 This is a flowchart of the continuous reaction process for preparing low-viscosity dimethyl silicone oil in the embodiments of this application.

[0019] In the diagram: 1. Batching device; 11. Material tank; 12. Batching vessel; 13. Intermediate tank; 2. Segmented fixed bed device; 21. First fixed bed; 22. Second fixed bed; 23. Third fixed bed; 24. Crude product tank; 3. Purification device; 31. De-saturation tower; 32. Product tank. Detailed Implementation

[0020] The present application will be further described below with reference to specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0021] In the description of this application, it should be noted that the directional terms such as "center", "lateral", "longitudinal", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", and "counterclockwise" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this application.

[0022] It should be noted that the terms "first," "second," etc., in the specification and claims of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0023] The terms “comprising” and “having”, and any variations thereof, in the specification and claims of this application are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0024] Traditional fixed-bed methods for preparing dimethyl silicone oil have low experimental yields, and the catalyst activity in fixed-bed reactors gradually decreases over time due to various factors. For example, coke deposits generated during the reaction can cover the active sites of the catalyst, hindering contact between reactants and the catalyst, thus reducing catalytic efficiency. Furthermore, the catalyst may sinter at high temperatures, leading to a reduction in active surface area and further degrading catalytic performance. To maintain the reaction, the reaction temperature is usually increased, but this may exacerbate catalyst deactivation, reducing conversion and selectivity, and increasing impurity content in the product, thereby affecting product stability and quality.

[0025] Therefore, as Figure 1 As shown, this application provides a system for continuous production of low-viscosity dimethyl silicone oil, including a batching device 1, a segmented fixed bed device 2 and a purification device 3 arranged in sequence. The material composed of octamethylcyclotetrasiloxane (D4) and hexamethyldisiloxane (MM) passes through the batching device 1, the segmented fixed bed device 2 and the purification device 3 in sequence to prepare a dimethyl silicone oil product with a higher experimental yield.

[0026] Furthermore, the batching device 1 includes a material tank 11, a batching vessel 12, and an intermediate tank 13. The material tank 11 can be used for short-term material storage and serves to buffer the entry of materials into the batching vessel 12, balancing the supply and demand of materials and ensuring the continuity of the entire production process. The batching vessel 12 can be set according to production needs to adjust the material stirring speed and the temperature required for material mixing, ensuring uniform mixing of materials. The intermediate tank 13 is used for temporary material storage, stabilizing the material flow rate, ensuring uniform and stable subsequent feeding, and avoiding the impact of material supply fluctuations on subsequent reaction processes, thereby improving the reaction efficiency and product quality of the production system.

[0027] Furthermore, the segmented fixed bed device 2 includes a first fixed bed 21, a second fixed bed 22, and a third fixed bed 23, and a crude product tank 24. The first fixed bed 21, the second fixed bed 22, and the third fixed bed 23 are all filled with equal amounts of catalyst to fully catalyze the mixture of octamethylcyclotetrasiloxane (D4) and hexamethyldisiloxane (MM) fed into the fixed bed. The crude product tank 24 is used to store the crude product after preliminary processing, and plays a buffer role to ensure the continuity of subsequent refining or processing steps.

[0028] Furthermore, the purification device 3 includes a de-boiling tower 31 and a product tank 32. The de-boiling tower 31 is mainly used to separate and purify low-boiling-point components in the mixture. By heating and distillation, the low-boiling-point components are separated from the crude dimethyl silicone oil product, thereby improving the purity and quality of the dimethyl silicone oil product. The product tank 32 is used to store the prepared low-viscosity dimethyl silicone oil product.

[0029] Furthermore, such as Figure 1As shown, a material composed of precisely metered octamethylcyclotetrasiloxane (D4) and hexamethyldisiloxane (MM) is fed into material tank 11. This material is then piped from material tank 11 to batching vessel 12, which is equipped with a high-efficiency stirring system and temperature control system, for mixing. The mixed material is then pumped from batching vessel 12 to intermediate tank 13 for buffering and stabilizing the flow rate. The material buffered in intermediate tank 13 is then pumped sequentially to first fixed bed 21, second fixed bed 22, and third fixed bed 23 for catalytic reaction, producing crude dimethyl silicone oil. This crude product is piped to crude product tank 24 for buffering, ensuring the feed stability of subsequent purification unit 3. The crude dimethyl silicone oil is then pumped to de-boiling tower 31, where low-boiling-point impurities are effectively removed, producing dimethyl silicone oil with a purity close to 100% and low ion content. Finally, the generated low-viscosity dimethyl silicone oil is piped to product tank 32 for sealed storage, awaiting subsequent application.

[0030] In some embodiments, the segmented fixed bed device 2 includes at least two fixed beds, each filled with an equal amount of catalyst to ensure that the material can undergo a sufficient catalytic reaction, thereby improving the utilization and conversion rate of the material.

[0031] In some embodiments, the fixed beds in the segmented fixed bed device 2 are connected sequentially from bottom to top, and the mixed material is continuously transported against gravity by the extraction pump, which facilitates the step-by-step processing and monitoring of the material and ensures quality control at each stage.

[0032] In some embodiments, the fixed beds in the segmented fixed bed device 2 are connected in series, and the material can gradually come into contact with the catalyst in each fixed bed to achieve segmented reaction. Compared with a single fixed bed with an equal amount of catalyst, the material can achieve more efficient mixing, dispersion and catalysis when the residence time remains unchanged, thereby improving the experimental yield and product stability.

[0033] In some embodiments, each fixed bed in the segmented fixed bed device 2 is filled with the same dose of catalyst to ensure that the contact area and reaction time between the material and the catalyst in each fixed bed are consistent, thereby avoiding affecting the production ratio and purity of the target product.

[0034] In some embodiments, different dosages of catalyst are added to each fixed bed in the segmented fixed bed device 2 to suit the characteristics of different reaction stages. In the initial stage of the reaction, the highly active catalyst can rapidly convert high concentrations of materials, while in subsequent beds, the catalyst can be adjusted according to the remaining concentration of materials and reaction characteristics, thereby reducing the occurrence of side reactions and improving the selectivity of the target product.

[0035] In some embodiments, after sufficient catalyst is filled in the fixed bed, the remaining space is filled with glass beads. These glass beads can both support the catalyst and disperse the material in the fixed bed, and also act as a physical barrier to prevent catalyst loss and reduce the pressure generated by the material flow in the fixed bed.

[0036] In some embodiments, the remaining space in the fixed bed after the catalyst is filled can be filled with materials such as inert alumina balls, ceramics, or quartz sand to support the catalyst, disperse the material, and reduce the pressure generated by the material flow rate in the fixed bed.

[0037] Based on the aforementioned continuous production system for low-viscosity dimethyl silicone oil, the specific implementation steps for preparing low-viscosity dimethyl silicone oil in this application are as follows:

[0038] Example 1

[0039] S10. Weigh materials (D4 and MM) with a mass ratio of 58:1 and put them into material tank 11. After being buffered by material tank 11, the materials are transported through pipeline to batching kettle 12 heated to 80°C and stirred continuously for 1 hour. After stirring, the materials in batching kettle 12 are pumped through the extraction pump to intermediate tank 13 where the temperature is maintained at 80°C for buffering.

[0040] S20. Subsequently, the material buffered in intermediate tank 13 is filtered by a filter and then sequentially pumped to the first fixed bed 21, the second fixed bed 22 and the third fixed bed 23 with a flow rate of 500 kg / h and a temperature of 65°C for catalytic reaction. The resulting crude dimethyl silicone oil product is then buffered in crude product tank 24.

[0041] S30. Subsequently, the crude dimethyl silicone oil buffered in the crude product tank 24 is transported to the de-boiling tower 31 for purification by the extraction pump to remove low-boiling-point components from the crude dimethyl silicone oil. Finally, it is filtered to obtain colorless, transparent, neutral, low-viscosity dimethyl silicone oil, which is then stored in the product tank 32 for subsequent use.

[0042] Finally, the viscosity of the low-viscosity dimethyl silicone oil prepared in Example 1 was 100-300 mm. 2 / s, volatile matter 10-15%, dispersion coefficient 1.8-2.2.

[0043] Comparative Example 1

[0044] The difference between Comparative Example 1 and Example 1 is that in step S20 of the dimethyl silicone oil production system, only one fixed bed is used for the catalytic reaction of the mixed materials, and the final low-viscosity dimethyl silicone oil has a viscosity of 100-300 mm. 2The volatile matter content is 10-15%, and the dispersion coefficient is 2-2.2. Compared with Comparative Example 1, the dimethyl silicone oil prepared in this application has a wider dispersion coefficient range, which can adapt to different formulation requirements.

[0045] Compared with the prior art, this application adopts a segmented fixed bed device, which includes multiple fixed beds connected in series. The catalyst is divided into multiple portions and filled into multiple fixed beds connected in series. The multiple portions of catalyst react with the material in sequence, so that the material can be mixed, dispersed and catalyzed more effectively. Under the same experimental conditions, the segmented fixed bed device proposed in this application can effectively improve the experimental yield and product stability.

[0046] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by this application is defined by the appended claims and their equivalents.

Claims

1. A continuous production system for low-viscosity dimethyl silicone oil, comprising a batching device and a purification device, characterized in that, It also includes a segmented fixed bed device disposed between the batching device and the purification device. The segmented fixed bed device includes at least two fixed beds. The material is suitable for being stirred evenly in the batching device and then entering the fixed bed. After catalytic reaction, crude dimethyl silicone oil is obtained, and then low-viscosity dimethyl silicone oil is obtained through the purification device.

2. The continuous production system for low-viscosity dimethyl silicone oil according to claim 1, characterized in that, The fixed beds are connected in series.

3. The continuous production system for low-viscosity dimethyl silicone oil according to claim 2, characterized in that, The fixed beds are connected sequentially from bottom to top.

4. The continuous production system for low-viscosity dimethyl silicone oil according to claim 3, characterized in that, The packing material in each of the fixed beds includes a catalyst and glass beads.

5. The continuous production system for low-viscosity dimethyl silicone oil according to claim 4, characterized in that, The catalyst dosage packed in each of the fixed beds is the same.

6. The continuous production system for low-viscosity dimethyl silicone oil according to claim 4, characterized in that, The filling material in the fixed bed can also be inert alumina balls, ceramics, or quartz sand.

7. The continuous production system for low-viscosity dimethyl silicone oil according to claim 1, characterized in that, The segmented fixed-bed device also includes a crude product tank, suitable for buffering the crude dimethyl silicone oil product obtained after the fixed-bed catalytic reaction.

8. The continuous production system for low-viscosity dimethyl silicone oil according to claim 1, characterized in that, The batching device includes a material tank, a batching vessel, and an intermediate tank arranged in sequence. The material tank conveys material into the batching vessel. After the material is mixed evenly in the batching vessel, it is transported to the intermediate tank for buffering by a pump. The material mixture in the intermediate tank is filtered by a filter and then transported to each of the fixed beds by a pump for catalytic reaction.

9. A continuous production system for low-viscosity dimethyl silicone oil according to claim 1, characterized in that, The purification device includes a descaling tower and a product tank arranged in sequence. The descaling tower is suitable for purifying crude dimethyl silicone oil delivered by a pump. The product tank is suitable for storing low-viscosity dimethyl silicone oil after purification by the descaling tower and filtration by a filter.

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