Continuous catalytic cracking device and method for organic silicon high-boiling residues

Abstract

The invention provides a continuous catalytic cracking device and method for organic silicon high-boiling residues. The continuous catalytic cracking device comprises a gas supply unit, a feeding unit, a fixed bed reaction unit and a cooling unit which are connected in sequence, wherein the fixed bed reaction unit comprises a fixed bed reactor; the gas supply unit comprises a hydrogen supply pipeline and a nitrogen supply pipeline; the hydrogen supply pipeline is directly connected with the fixed bed reaction unit; the feeding unit comprises a stock solution storage device, and the stock solution storage device is connected with the fixed bed reaction unit after being subjected to nitrogen sealing through a nitrogen supply pipeline. The method provided by the invention can realize continuous production, high stability and large-scale operation, realizes high-value utilization of the low-value organic silicon high-boiling residues, reduces environmental pollution, reduces the hazardous waste treatment cost, improves economic benefits, and promotes green sustainable development of the organic silicon industry.

Description

Technical Field

[0001] The invention relates to the technical field of organosilicon monomer production, and in particular to a continuous catalytic cracking device and method for organosilicon high-boiling substances. Background Art

[0002] Silicone is an important chemical intermediate, known as "industrial MSG", and is the main indicator for measuring the development of the country's silicone industry. Silicone products include silicone oil, silicone rubber, silicone resin and silane coupling agent, which are widely used in industries such as construction, electronic appliances, medical treatment and new energy. At present, silicone monomers are mainly produced by the "direct method". In this process, in addition to the main product dimethyldichlorosilane (M2), by-products such as methyltrichlorosilane (M1), trimethylchlorosilane (M3) and silicone high boiling products are often produced.

[0003] Organosilicon high-boiling substances account for 8-10% of the output of chlorosilane monomers, and are mainly composed of substances containing Si-Si, Si-CH2-Si, Si-O-Si and Si-Si-Si bonds, among which the main components of Si-Si components are MeSiCl2-SiCl2Me and MeSiCl2-SiClMe2. Organosilicon high-boiling substances have complex compositions and will undergo hydrolysis reactions when exposed to air and water to generate substances such as hydrogen chloride and silicone oil, while producing a pungent odor, which will cause serious harm to the environment. In addition, organosilicon high-boiling substances are highly corrosive and have high requirements for storage materials. With the annual expansion of organosilicon production capacity, the large accumulation of organosilicon chlorosilanes has increased the cost of hazardous waste treatment for enterprises, causing huge environmental safety risks, and gradually becoming an obstacle to the development of the organosilicon industry.

[0004] At present, relevant studies have reported methods for preparing methylchlorosilane monomers by cracking high boiling products, such as: US2681355A; US5430168A; US2709176A; US5288892A; US5877337; US5326896A, etc. Among them, the most commonly used catalyst is tri-n-butylamine, but tri-n-butylamine is a highly toxic chemical and does not meet the requirements of green chemistry. At the same time, the most commonly used reaction process is a batch or semi-continuous reaction process, which has problems such as inability to produce continuously, difficulty in separating homogeneous catalysis, high hazardous waste production, and poor selectivity of target products.

[0005] Therefore, it is necessary to develop new processes and equipment for treating high boiling points of organosilicon. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a continuous catalytic cracking device and method for high-boiling organosilicon products, which solves the problems of the existing use of tri-n-butylamine as a catalyst for the continuous production of high-boiling organosilicon products, low resource utilization, and large hazardous waste production. The method provided by the present invention recycles high-boiling organosilicon products, realizes waste resource utilization, increases the output of dimethyldichlorosilane, reduces the cost of hazardous waste treatment, increases the utilization efficiency of silicon resources, reduces the pollution and harm of high-boiling organosilicon products to the environment, and achieves the purpose of reducing costs and increasing efficiency and improving economic benefits.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a continuous catalytic cracking device for high-boiling organic silicon, the continuous catalytic cracking device comprising a gas supply unit, a feeding unit, a fixed bed reaction unit and a cooling unit connected in sequence; wherein the fixed bed reaction unit comprises a fixed bed reactor; the gas supply unit comprises a hydrogen gas supply pipeline and a nitrogen gas supply pipeline; the hydrogen gas supply pipeline is directly connected to the fixed bed reaction unit; the feeding unit comprises a stock liquid storage device, and the stock liquid storage device is connected to the fixed bed reaction unit after being sealed with nitrogen through the nitrogen gas supply pipeline.

[0009] The present invention develops a set of devices capable of realizing continuous catalytic cracking of high-boiling organic silicon products, which can catalytically convert high-boiling organic silicon products into high-value monosilane. Compared with a reactor, the device has the following advantages: firstly, relying on a solid-phase catalyst, the online separation of the reaction materials and the catalyst can be directly realized, thus realizing the continuous cracking reaction; secondly, there is no need to use toxic amine-containing catalysts, which is more environmentally friendly; and the process can be conducive to the complete conversion of high-boiling organic silicon products, improve the selectivity of dimethyldichlorosilane, and improve production efficiency.

[0010] Preferably, the feeding unit further comprises a material conveying device, and the material conveying device is respectively connected to the raw liquid storage device and the fixed bed reaction unit.

[0011] Preferably, the feeding unit further comprises a metering device arranged at the lower part of the stock liquid storage device, and a nitrogen sealing device arranged inside the stock liquid storage device. The nitrogen sealing device prevents air from entering the storage tank by controlling the nitrogen sealing pressure. The metering device is preferably a large-range, high-precision balance to accurately control the feeding amount.

[0012] Preferably, the stock liquid storage device is provided with at least two vents for setting up a nitrogen sealing device.

[0013] Preferably, the internal material of the raw liquid storage device includes Hastelloy and / or 316L stainless steel.

[0014] Preferably, the top of the stock liquid storage device is provided with a storage inlet, the bottom is provided with a storage outlet, and a ball valve is provided at the storage outlet. The ball valve is connected to the metering device.

[0015] Preferably, the nitrogen gas supply pipeline and the hydrogen gas supply pipeline are each independently provided with a check valve, a gas flow controller, a pressure gauge and a safety valve. The check valve is used to prevent the gas or material in the reactor from flowing back. The safety valve is set according to the safety regulations. The safety valve is used for emergency emptying when the reaction pipeline is blocked and the material in the system cannot be discharged, so as to prevent the system from overpressure and ensure safety.

[0016] Preferably, the fixed bed reactor comprises a first reaction outlet and a second reaction outlet.

[0017] Preferably, the first reaction outlet is connected to the inlet of the cooling unit.

[0018] Preferably, a reaction material inlet is arranged at the top of the fixed bed reactor, and a reaction material outlet is arranged at the bottom.

[0019] Preferably, a backup pressure valve is provided on the fixed bed reactor.

[0020] Preferably, the fixed bed reaction unit further comprises a preheating mixer arranged before the fixed bed reactor.

[0021] Preferably, the cooling unit comprises a cooler and a recovery device connected in sequence. The cooler of the present invention adopts a circulating cooling device to ensure that the cooling tank is kept at -15°C to -2°C, and the gaseous product is quickly condensed into liquid.

[0022] Preferably, the outlet of the cooler comprises a first cooling outlet connected to the inlet of the recovery device and a second cooling outlet for emptying.

[0023] Preferably, the second cooling outlet is connected to an exhaust port.

[0024] Generally speaking, in the pilot and laboratory stages of the present invention, the present invention preferably includes an online analysis unit. When in actual industrial operation, commonly used industrial detection instruments can be used for analysis or sampling points can be designed for analysis.

[0025] Preferably, the second reaction outlet is connected to the online analysis unit.

[0026] Preferably, the online analysis unit comprises a six-way valve, a heat preservation device and a gas chromatography analysis device.

[0027] Preferably, the outlet of the online analysis unit is provided with an emptying port, which is used for emergency emptying when the reaction pipeline is blocked and the substances in the system cannot be discharged, so as to prevent the system from overpressure and ensure safety.

[0028] In a second aspect, the present invention provides a method for continuous catalytic cracking of high-boiling organosilicon products. The continuous catalytic cracking method is carried out using the continuous catalytic cracking device for high-boiling organosilicon products described in the first aspect.

[0029] As a preferred technical solution of the present invention, the continuous catalytic cracking method comprises: introducing a high-boiling organic silicon stock solution and hydrogen into a fixed bed reactor filled with a catalyst to carry out a continuous catalytic cracking reaction, and sending the reaction materials into a cooling unit for cooling to obtain a cracked product.

[0030] The present invention can continuously carry out catalytic cracking reaction of high-boiling organic silicon products, realize high-value utilization of wastes, generate dimethyldichlorosilane, and achieve the purpose of reducing costs, increasing efficiency, reducing pollution and improving economic benefits.

[0031] Preferably, the stock solution storage device and the fixed bed reactor are first purged with nitrogen, and then the organosilicon high boiling point stock solution and hydrogen are introduced into the fixed bed reactor filled with the catalyst.

[0032] The present invention preferably uses nitrogen purging first and then performs the cracking reaction in a fixed bed to prevent air and water from remaining. The final reaction effect is better, and the subsequent cooling by a cooling unit can significantly improve the conversion rate and selectivity of the reaction.

[0033] In the present invention, the high-boiling organic silicon stock solution can be filtered, distilled or rotary evaporated to remove solid residue components and high-boiling impurities. High-boiling substances often contain a small amount of copper catalyst residues, hydrolysis products and other solid substances. If not treated, they will clog the pump or catalyst bed, causing feed fluctuations, pump damage, system pressure fluctuations and even overpressure. Therefore, the solid residue is removed, which can make the system run stably and extend the start-up cycle.

[0034] Preferably, the organosilicon high boiling point stock solution originally includes but is not limited to any one of heavy separation tower high boiling points, heavy refinement tower high boiling points or slurry residue supernatant liquid, or a combination of at least two of them, wherein typical but non-limiting combinations are a combination of heavy separation tower high boiling points and heavy refinement tower high boiling points, a combination of slurry residue supernatant liquid and heavy refinement tower high boiling points, and a combination of heavy separation tower high boiling points and slurry residue supernatant liquid.

[0035] Preferably, the organic matter in the organic silicon high boiling point stock solution has any one of Si-Si group, Si-CH2-Si group, Si-O-Si group or Si-Si-Si group, or a combination of at least two of them, wherein typical but non-limiting combinations are a combination of Si-Si group and Si-CH2-Si group, a combination of Si-Si-Si group and Si-CH2-Si group, and a combination of Si-Si group and Si-Si-Si group.

[0036] Preferably, the content of Si-Si component in the high-boiling point organic silicon stock solution is greater than 50wt%, for example, it can be 50wt%, 52wt%, 53wt%, 55wt%, 58wt%, 60wt%, 62wt%, 63wt%, 65wt%, 68wt%, 70wt%, 72wt% or 75wt%, etc.

[0037] Preferably, the Si-Si component in the organosilicon high boiling point stock solution includes any one of MeSiCl2-SiCl2Me, MeSiCl2-SiClMe2 or Me2SiCl-SiClMe2, or a combination of at least two thereof, wherein typical but non-limiting combinations are a combination of MeSiCl2-SiCl2Me and MeSiCl2-SiClMe2, a combination of Me2SiCl-SiClMe2 and MeSiCl2-SiClMe2, and a combination of MeSiCl2-SiCl2Me and Me2SiCl-SiClMe2.

[0038] Preferably, the organosilicon high boiling point stock solution contains a monosilane component, and the monosilane component includes any one of dimethyldichlorosilane, methyltrichlorosilane, trimethylchlorosilane or methylhydrogendichlorosilane, or a combination of at least two thereof, wherein typical but non-limiting combinations are a combination of dimethyldichlorosilane and methyltrichlorosilane, a combination of trimethylchlorosilane and methyltrichlorosilane, a combination of dimethyldichlorosilane and trimethylchlorosilane, and a combination of dimethyldichlorosilane and methylhydrogendichlorosilane.

[0039] Preferably, the content of the monosilane component in the high-boiling organosilicon stock solution is 10 to 30 wt%, for example, it can be 10 wt%, 13 wt%, 15 wt%, 17 wt%, 19 wt%, 22 wt%, 24 wt%, 26 wt%, 28 wt% or 30 wt%, etc., but is not limited to the listed values, and other values ​​not listed within this range are also applicable.

[0040] Preferably, the catalyst comprises any one or a combination of at least two of a silicon-aluminum compound, an aluminum-based compound, a metal oxide or a metal element, wherein typical but non-limiting combinations are a combination of a silicon-aluminum compound and an aluminum-based compound, a combination of a metal oxide and an aluminum-based compound, a combination of a silicon-aluminum compound and a metal oxide, and a combination of a metal element and an aluminum-based compound.

[0041] Preferably, the silicon-aluminum compound is a molecular sieve.

[0042] Preferably, the silicon-aluminum molar ratio SiO2 / Al2O3 in the silicon-aluminum compound is 50-200:1, for example, it can be 50:1, 67:1, 84:1, 100:1, 117:1, 134:1, 150:1, 167:1, 184:1 or 200:1, etc., but it is not limited to the listed values, and other unlisted values ​​in this range are also applicable. Molecular sieve is a common and readily available catalyst carrier, which is acidic and has a certain catalytic ability. Loading various components on the molecular sieve can effectively improve the catalytic performance, and has a certain strength, which is conducive to industrial application.

[0043] Preferably, the aluminum-based compound comprises any one of AlCl3, Al2O3, NaAlCl4 or KAlCl4 or a combination of at least two thereof, wherein a typical but non-limiting combination is a combination of AlCl3 and Al2O3, a combination of NaAlCl4 and Al2O3, a combination of AlCl3 and NaAlCl4, a combination of KAlCl4 and Al2O3, and a combination of AlCl3 and KAlCl4. Aluminum-based compounds have Lewis acidity, can catalyze the breaking of Si-Si bonds in high-boiling organic silicon products, and are conducive to promoting the conversion of high-boiling organic silicon products into chlorosilane monomers. In addition, AlCl3 can promote the disproportionation rearrangement of functional groups in methyltrichlorosilane and trimethylchlorosilane to generate dimethyldichlorosilane, which will greatly increase the proportion of dimethyldichlorosilane in the product.

[0044] Preferably, the metal in the metal oxide or metal element independently includes any one or a combination of at least two of Ni, Mo, Fe, Co, Zn or Cu, wherein a typical but non-limiting combination is a combination of Ni and Mo, a combination of Fe and Mo, a combination of Ni and Fe, a combination of Co and Zn, a combination of Ni and Co, and a combination of Cu and Mo. The above metals can be loaded on the silicon-aluminum molecular sieve to form a multifunctional active site. On the one hand, the site can promote the dissociation of hydrogen, thereby promoting the hydrocracking of organosilicon high boiling points. On the other hand, the site can also promote the disproportionation of chlorosilanes and improve the selectivity of dimethyldichlorosilane.

[0045] Preferably, the temperature of the continuous catalytic cracking reaction is 200-500°C, for example, it can be 200°C, 210°C, 220°C, 250°C, 280°C, 300°C, 323°C, 345°C, 367°C, 389°C, 412°C, 434°C, 456°C, 478°C or 500°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0046] Preferably, the pressure of the continuous catalytic cracking reaction is 0.1-2.0 MPa, for example, it can be 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.5 MPa, 0.7 MPa, 0.9 MPa, 1 MPa, 1.2 MPa, 1.4 MPa, 1.5 MPa, 1.7 MPa, 1.9 MPa or 2.0 MPa, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0047] The pressure mentioned in the present invention refers to the hydrogen pressure. Increasing the hydrogen pressure can increase the hydrogen concentration in the fixed bed, improve the degree of hydrogen dissociation, and promote the forward cracking reaction of high-boiling substances in organic silicon. However, excessively increasing the hydrogen flow rate will reduce the residence time of the stock solution in the bed. Therefore, choosing appropriate hydrogen pressure and hydrogen flow rate is beneficial to the complete conversion of high-boiling substances in organic silicon, improving the selectivity of dimethyldichlorosilane, and improving production efficiency.

[0048] Preferably, the hydrogen flow rate of the continuous catalytic cracking reaction is 50 to 400 mL / min, for example, it can be 50 mL / min, 89 mL / min, 128 mL / min, 167 mL / min, 206 mL / min, 245 mL / min, 284 mL / min, 323 mL / min, 362 mL / min or 400 mL / min, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0049] Preferably, the mass space velocity of the feed liquid of the organosilicon high boiling point stock solution is 0.01 to 10 h -1 , for example, it can be 0.01h -1 、0.02h -1 、0.05h -1 、0.08h -1 , 0.1h -1 , 0.5h -1 , 1.0h -1 , 2.0h -1 , 5.0h -1 , 6.8h -1 , 8.1h -1 , 9.4h -1 or 10h -1 The above values ​​are not limited to the above values, and other values ​​not listed in the above values ​​are also applicable.

[0050] In the present invention, the feed amount of high boiling substances affects the weight hourly space velocity of the reaction, and setting a suitable feed amount is beneficial to the conversion of high boiling substances.

[0051] Preferably, the cooling temperature is -15°C to -2°C, for example, it can be -15°C, -10°C, -8°C, -7°C, -6.5°C, -6°C, -5.5°C, -5°C, -4.5°C, -4°C, -3.5°C, -3°C, -2.5°C or -2°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0052] Preferably, the organosilicon high boiling point stock solution and hydrogen are first introduced into a preheating mixer for preheating and mixing, and then the mixed stream is introduced into a fixed bed reactor.

[0053] Preferably, the preheating temperature is 300-400°C, for example, it can be 300°C, 310°C, 320°C, 323°C, 330°C, 345°C, 350°C, 367°C, 389°C, 390°C, 395°C or 400°C, but is not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0054] Preferably, during the continuous catalytic cracking reaction and cooling process, the reaction materials are sent to an online analysis unit for simultaneous detection and analysis of the material composition.

[0055] Compared with the prior art, the present invention has at least the following beneficial effects:

[0056] (1) The continuous catalytic cracking device for high-boiling organic silicon products provided by the present invention realizes the recycling of high-boiling organic silicon products, thereby reducing the safety hazards and environmental risks caused by the long-term and large-scale accumulation of high-boiling organic silicon products.

[0057] (2) The continuous catalytic cracking method of high-boiling organosilicon products provided by the present invention is simple and easy to operate. The fixed-bed catalytic process can achieve continuous production and can be operated continuously for more than 3 months. It reduces the problems of the original kettle cracking process such as difficulty in judging the reaction endpoint, low conversion rate, and inability to produce continuously, and is suitable for large-scale promotion and utilization.

[0058] (3) The continuous catalytic cracking method of high-boiling organosilicon products provided by the present invention can use green catalysts instead of the highly toxic tri-n-butylamine catalyst, thereby achieving source control of environmental hazards and complying with the principles of green chemistry. At the same time, it reduces the problem of difficult separation of materials caused by homogeneous reactions, reduces the generation of hazardous waste, improves product quality, and can increase economic benefits.

[0059] (4) The continuous catalytic cracking method of high-boiling organosilicon provided by the present invention has a conversion rate of high-boiling organosilicon under preferred conditions of more than 90%, and in the final product, the selectivity of chlorosilane monomer is more than 90%, among which the selectivity of dimethyldichlorosilane is more than 60%. The process increases the utilization rate of silicon resources and improves the economy of silicon atoms. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a schematic diagram of the continuous catalytic cracking device of high-boiling organosilicon provided in Example 1 of the present invention.

[0061] In the figure: 1. gas supply unit; 11. hydrogen gas supply pipeline; 12. nitrogen gas supply pipeline; 2. feeding unit; 21. raw liquid storage device; 22. material conveying device; 3. fixed bed reaction unit; 31. fixed bed reactor; 4. cooling unit; 41. cooler; 42. recovery device; 5. online analysis unit; 51. gas chromatography analysis device. DETAILED DESCRIPTION

[0062] For the convenience of understanding the present invention, the present invention lists the following embodiments. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0063] It should be understood that, in the description of the present invention, the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0064] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0065] Those skilled in the art should understand that the present invention necessarily includes necessary pipelines, conventional valves and general pump equipment for realizing a complete process, but the above content does not belong to the main inventive point of the present invention. Those skilled in the art can add layouts on their own based on the process flow and equipment structure selection, and the present invention does not make special requirements and specific limitations on this.

[0066] Example 1

[0067] This embodiment provides a continuous catalytic cracking device for high-boiling organic silicon products. Figure 1 The continuous catalytic cracking device includes a gas supply unit 1, a feed unit 2, a fixed bed reaction unit 3 and a cooling unit 4 which are connected in sequence.

[0068] The fixed bed reaction unit 3 includes a fixed bed reactor 31; the fixed bed reactor 31 includes a first reaction outlet and a second reaction outlet; the first reaction outlet is connected to the inlet of the cooling unit 4; a reaction material inlet is arranged at the top of the fixed bed reactor 31, and a reaction material outlet is arranged at the bottom; the fixed bed reaction unit 3 also includes a preheating mixer arranged before the fixed bed reactor 31.

[0069] The cooling unit 4 includes a cooler 41 and a recovery device 42 connected in sequence; the outlet of the cooler 41 includes a first cooling outlet connected to the inlet of the recovery device 42 and a second cooling outlet for emptying; the second cooling outlet is connected to the emptying port. The second reaction outlet is connected to the online analysis unit 5.

[0070] The gas supply unit 1 includes a hydrogen gas supply pipeline 11 and a nitrogen gas supply pipeline 12 ; the hydrogen gas supply pipeline 11 is directly connected to the fixed bed reaction unit 3 .

[0071] The feed unit 2 includes a stock liquid storage device 21, and the nitrogen supply pipeline 12 first passes through the stock liquid storage device 21 and then is connected to the fixed bed reaction unit 3. The feed unit 2 also includes a material conveying device 22, and the material conveying device 22 is respectively connected to the stock liquid storage device 21 and the fixed bed reaction unit 3; the feed unit 2 also includes a metering device arranged at the bottom of the stock liquid storage device 21, and a nitrogen sealing device arranged inside the stock liquid storage device 21.

[0072] In the laboratory test stage, the continuous catalytic cracking device further comprises an online analysis unit 5. The online analysis unit 5 comprises a six-way valve, a heat preservation device and a gas chromatography analysis device 51. The outlet of the online analysis unit 5 is provided with an exhaust port.

[0073] In a specific embodiment, the internal material of the raw liquid storage device 21 includes Hastelloy and / or 316L stainless steel.

[0074] In a specific embodiment, the top of the stock liquid storage device 21 is provided with a storage inlet, the bottom is provided with a storage outlet, and a ball valve is provided at the storage outlet. The ball valve is connected to the metering device.

[0075] In a specific embodiment, the nitrogen gas supply pipeline 12 and the hydrogen gas supply pipeline 11 are each independently provided with a check valve, a gas flow controller, a pressure gauge and a safety valve.

[0076] In a specific embodiment, a backup pressure valve is provided on the fixed bed reactor 31 .

[0077] Example 2

[0078] This embodiment provides a continuous catalytic cracking device for high-boiling organic silicon. The continuous catalytic cracking device is the same as that of Embodiment 1 except that the feed unit is not provided with a metering device at the bottom of the stock liquid storage device.

[0079] Since no metering device is provided in this embodiment, the quality control effect of the feed in the continuous reaction process is poor and the overall production fluctuation is large.

[0080] Comparative Example 1

[0081] This comparative example provides a catalytic cracking device for high-boiling organic silicon. The catalytic cracking device is the same as Example 1 except that the fixed bed is replaced by a reaction kettle and a stirring device is provided inside.

[0082] Comparative Example 2

[0083] This comparative example provides a catalytic cracking device for high-boiling organic silicon, which is the same as Example 1 except that the nitrogen supply pipeline is directly connected to the fixed bed reaction unit without passing through the stock liquid storage device.

[0084] In this comparative example, since the stock liquid storage device was not nitrogen-sealed, there were problems such as material hydrolysis causing corrosion and leakage of the device.

[0085] The specific composition of the organosilicon high boiling point stock solution used in the following application examples and comparative application examples is shown in Table 1.

[0086] Table 1

[0087] Components content(%) <![CDATA[(CH3)3SiCl]]> 0.45 <![CDATA[CH3SiCl3]]> 3.51 <![CDATA[(CH3)2SiCl2]]> 8.21 <![CDATA[CH2=CHCH2SiCl2CH3]]> 1.87 <![CDATA[(CH3)3Si-CH2-Si(CH3)3]]> 2.21 <![CDATA[(CH3)3Si-Si(CH3)2Cl]]> 1.21 <![CDATA[(CH3)2ClSi-O-Si(CH3)2Cl]]> 1.53 <![CDATA[(CH3)2ClSi-Si(CH3)2Cl]]> 6.40 <![CDATA[CH3SiCl2-CH2CH2CH3]]> 4.52 <![CDATA[(CH3)3Si-CH2-Si(CH3)2Cl]]> 2.23 <![CDATA[(CH3)2SiCl-SiCH3Cl2]]> 25.68 <![CDATA[CH3SiCl2-SiCH3Cl2]]> 40.31 <![CDATA[(CH3)2ClSi-CH2-Si(CH3)2Cl]]> 1.87

[0088] Application Example 1

[0089] This application example provides a continuous catalytic cracking method for high-boiling organic silicon products. The continuous catalytic cracking method is carried out using the device provided in Example 1, and specifically includes:

[0090] First, the stock solution storage device (containing the organosilicon high-boiling material stock solution) and the fixed bed reactor (the reaction tube diameter is 20 mm) were purged 8 times with nitrogen, and the feed pump was turned on. The organosilicon high-boiling material stock solution and hydrogen were first introduced into the preheating mixer for preheating and mixing at 400° C., and then the obtained mixed stream was introduced into the fixed bed reactor filled with catalyst (5.0wt% Ni-35%Beta / 60%Al2O3, bed height is 25cm), and continuous catalytic cracking reaction was carried out under the conditions of 400° C. and 1.2MPa. The feed mass space velocity of the organosilicon high-boiling material stock solution in the continuous catalytic cracking reaction was 1.0h -1 The reaction materials are fed into a cooling unit through a three-way connector to be cooled at -10°C to obtain cracking products; during the continuous catalytic cracking reaction and cooling process, trace amounts of reaction materials are fed into an online analysis unit to perform synchronous detection and analysis of the material composition.

[0091] Application Example 2

[0092] This application example provides a continuous catalytic cracking method for high-boiling organic silicon products. The continuous catalytic cracking method is carried out using the device provided in Example 1, and specifically includes:

[0093] First, the stock solution storage device (containing the organosilicon high-boiling material stock solution) and the fixed bed reactor (the reaction tube diameter is 20 mm) are purged 10 times with nitrogen, and the feed pump is turned on. The organosilicon high-boiling material stock solution and hydrogen are first introduced into the preheating mixer for preheating and mixing at 300° C., and then the obtained mixed stream is introduced into the fixed bed reactor filled with the catalyst (12.2wt% Ni-25wt% Beta / 62.8wt% Al2O3, the bed height is 20 cm), and a continuous catalytic cracking reaction is carried out at 300° C. and 2MPa. The feed mass space velocity of the organosilicon high-boiling material stock solution in the continuous catalytic cracking reaction is 3.0h -1 The reaction materials are sent to the cooling unit through a three-way connector to be cooled at -5°C to obtain cracking products; during the continuous catalytic cracking reaction and cooling process, trace amounts of reaction materials are sent to the online analysis unit to perform synchronous detection and analysis on the material composition.

[0094] Application Example 3

[0095] This application example provides a continuous catalytic cracking method for high-boiling organic silicon products. The continuous catalytic cracking method is carried out using the device provided in Example 1, and specifically includes:

[0096] First, the stock solution storage device (containing the organosilicon high-boiling stock solution) and the fixed bed reactor (the reaction tube diameter is 20 mm) are purged 5 times with nitrogen, and the feed pump is turned on. The organosilicon high-boiling stock solution and hydrogen are first introduced into the preheating mixer for preheating and mixing at 500°C, and then the obtained mixed stream is introduced into the fixed bed reactor filled with the catalyst (10.6wt% Co-55wt% ZSM-5 / 34.4wt% Al2O3, the bed height is 20cm), and a continuous catalytic cracking reaction is carried out at 500°C and 0.8MPa. The feed mass space velocity of the organosilicon high-boiling stock solution in the continuous catalytic cracking reaction is 8.0h -1 The reaction materials are sent to the cooling unit through a three-way connector to be cooled at -14°C to obtain cracking products; during the continuous catalytic cracking reaction and cooling process, trace amounts of reaction materials are sent to the online analysis unit to perform synchronous detection and analysis on the material composition.

[0097] Application Example 4

[0098] This application example provides a continuous catalytic cracking method for high-boiling organic silicon products. The continuous catalytic cracking method is carried out using the device provided in Example 1, and specifically includes:

[0099] First, the stock solution storage device (containing organosilicon high-boiling material stock solution) and the fixed bed reactor (reaction tube diameter is 20 mm) are purged 7 times with nitrogen, and the feed pump is turned on. The organosilicon high-boiling material stock solution and hydrogen are first introduced into the preheating mixer for preheating and mixing at 350° C., and then the obtained mixed stream is introduced into the fixed bed reactor filled with catalyst (12.2wt% Ni-33wt% USY / 54.8wt% Al2O3, bed height is 20 cm), and a continuous catalytic cracking reaction is carried out at 350° C. and 0.5MPa. The feed mass space velocity of the organosilicon high-boiling material stock solution in the continuous catalytic cracking reaction is 5.0h -1 The reaction materials are sent to the cooling unit through a three-way connector to be cooled at -7°C to obtain cracking products; during the continuous catalytic cracking reaction and cooling process, trace amounts of reaction materials are sent to the online analysis unit to perform synchronous detection and analysis on the material composition.

[0100] Application Example 5

[0101] This application example provides a method for continuous catalytic cracking of high-boiling organic silicon products. The method is the same as that of application example 1 except that the temperature of the continuous catalytic cracking reaction is 190° C., and will not be described in detail here.

[0102] Application Example 6

[0103] This application example provides a continuous catalytic cracking method for high-boiling organic silicon products. The continuous catalytic cracking method is the same as that of application example 1 except that the temperature of the continuous catalytic cracking reaction is 600° C., and will not be described in detail here.

[0104] Application Example 7

[0105] This application example provides a continuous catalytic cracking method for high-boiling organic silicon products. The continuous catalytic cracking method is the same as that of Application Example 1 except that the pressure of the continuous catalytic cracking reaction is 101.kPa, and will not be described in detail here.

[0106] In this application example, the cracking reaction is difficult to proceed normally due to the low pressure of the cracking reaction.

[0107] Application Example 8

[0108] This application example provides a continuous catalytic cracking method for high-boiling organic silicon products. The mass space velocity of the continuous catalytic cracking method is 12h when the feed liquid of the high-boiling organic silicon product stock solution is removed. -1 , the rest are the same as those in Application Example 1 and will not be described in detail here.

[0109] Application Example 9 and Application Comparative Examples 1 to 2

[0110] Application Example 9 and Application Comparative Examples 1-2 provide a method for catalytic cracking of high-boiling-point organic silicon. The method for catalytic cracking of high-boiling-point organic silicon is the same as Application Example 1 except that the catalytic cracking devices for high-boiling-point organic silicon in Example 2 and Comparative Examples 1-2 are used respectively, and the rest are not repeated here.

[0111] The analysis results of the above application examples and application comparison examples are shown in Table 2.

[0112] Table 2

[0113]

[0114]

[0115] “ / ” in Tables 1 and 2 indicates no relevant data.

[0116] From Table 2, we can see the following points:

[0117] (1) It can be seen from Application Examples 1 to 4 that the continuous catalytic cracking method for high-boiling organosilicon products provided by the present invention can not only operate continuously, but also achieve a cracking rate of high-boiling organosilicon products of more than 90.1%, and the selectivity of dimethyldichlorosilane is more than 63%.

[0118] (2) By comparing Application Example 1 with Application Examples 5 to 6, it can be seen that the temperature of the continuous catalytic cracking reaction in Application Example 5 is relatively low, resulting in the conversion rate of high-boiling organic silicon products decreasing to 25.3%. In Application Example 6, although the conversion rate of high-boiling organic silicon products is as high as 97.9%, the selectivity of dimethyldichlorosilane is only 30.1%. This shows that the present invention preferably controls the temperature of the cracking reaction in the continuous catalytic cracking reaction, and has a better conversion rate and selectivity for dimethyldichlorosilane.

[0119] (3) By comparing Application Example 1 with Application Examples 7 to 8, it can be seen that the present invention preferably controls the pressure and mass space velocity of the feed liquid in the continuous catalytic cracking reaction within a reasonable range, thereby achieving better catalytic activity and selectivity for dimethyldichlorosilane.

[0120] (4) By comparing Application Example 1 with Application Comparative Examples 1 to 2, it can be seen that the reaction kettle used in Application Comparative Example 1 not only cannot operate continuously, but also the conversion rate of high-boiling organic silicon products is only 30.2%, and the selectivity is only 65.3%. In Application Comparative Example 2, there is no nitrogen sealing, and there are problems such as material hydrolysis causing corrosion and leakage of the device.

[0121] The present invention illustrates the detailed features of the present invention through the above embodiments, but the present invention is not limited to the above detailed features, that is, it does not mean that the present invention must rely on the above detailed features to be implemented. Those skilled in the art should understand that any improvement to the present invention, equivalent replacement of the technical features selected by the present invention, addition of auxiliary technical features, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A continuous catalytic cracking device for high-boiling organic silicon, characterized in that: The continuous catalytic cracking device comprises a gas supply unit, a feed unit, a fixed bed reaction unit and a cooling unit connected in sequence; Wherein, the fixed bed reaction unit includes a fixed bed reactor; The gas supply unit includes a hydrogen gas supply pipeline and a nitrogen gas supply pipeline; the hydrogen gas supply pipeline is directly connected to the fixed bed reaction unit; The feed unit comprises a stock liquid storage device, and the stock liquid storage device is connected to the fixed bed reaction unit after being sealed with nitrogen through a nitrogen supply pipeline.

2. The continuous catalytic cracking device according to claim 1, characterized in that: The feeding unit further comprises a material conveying device, and the material conveying device is respectively connected to the stock solution storage device and the fixed bed reaction unit; Preferably, the feeding unit further comprises a metering device arranged at the lower part of the stock liquid storage device, and a nitrogen sealing device arranged inside the stock liquid storage device.

3. The continuous catalytic cracking device according to claim 1 or 2, characterized in that: The fixed bed reactor comprises a first reaction outlet and a second reaction outlet; Preferably, the first reaction outlet is connected to the inlet of the cooling unit; Preferably, a reaction material inlet is arranged at the top of the fixed bed reactor, and a reaction material outlet is arranged at the bottom; Preferably, the fixed bed reaction unit further comprises a preheating mixer arranged before the fixed bed reactor; Preferably, the cooling unit comprises a cooler and a recovery device connected in sequence; Preferably, the outlet of the cooler comprises a first cooling outlet connected to the inlet of the recovery device and a second cooling outlet for emptying; Preferably, the second cooling outlet is connected to an exhaust port.

4. A continuous catalytic cracking method for high-boiling organic silicon products, characterized in that: The continuous catalytic cracking method is carried out using the continuous catalytic cracking device for high-boiling organic silicon products according to any one of claims 1 to 3.

5. The method according to claim 4, characterized in that The continuous catalytic cracking method comprises: The high-boiling organic silicon raw liquid and hydrogen are introduced into a fixed bed reactor filled with a catalyst to carry out a continuous catalytic cracking reaction, and the reaction materials are sent to a cooling unit for cooling to obtain a cracked product.

6. The method according to claim 4 or 5, characterized in that: The organic matter in the organic silicon high boiling point stock solution has any one of Si-Si group, Si-CH2-Si group, Si-O-Si group or Si-Si-Si group or a combination of at least two; Preferably, the content of Si-Si components in the organic silicon high boiling point stock solution is greater than 50wt%; Preferably, the Si-Si component in the organosilicon high boiling point stock solution includes any one or a combination of at least two of MeSiCl2-SiCl2Me, MeSiCl2-SiClMe2 or Me2SiCl-SiClMe2; Preferably, the organosilicon high boiling point stock solution contains a monosilane component, and the monosilane component includes any one of dimethyldichlorosilane, methyltrichlorosilane, trimethylchlorosilane or methylhydrogendichlorosilane, or a combination of at least two thereof; Preferably, the content of the monosilane component in the organic silicon high boiling point stock solution is 10 to 30 wt%.

7. The method according to any one of claims 4 to 6, characterized in that: The catalyst comprises any one or a combination of at least two of a silicon-aluminum compound, an aluminum-based compound, a metal oxide or a metal element; Preferably, the silicon-aluminum compound is a molecular sieve; Preferably, the silicon-aluminum molar ratio of the silicon-aluminum compound is SiO2 / Al2O3=50-200:1; Preferably, the aluminum-based compound includes any one or a combination of at least two of AlCl3, Al2O3, NaAlCl4 or KAlCl4; Preferably, the metal in the metal oxide or metal element independently includes any one of Ni, Mo, Fe, Co, Zn or Cu, or a combination of at least two of them.

8. The method according to any one of claims 4 to 7, characterized in that: The temperature of the continuous catalytic cracking reaction is 200-500°C; Preferably, the pressure of the continuous catalytic cracking reaction is 0.1-2.0 MPa; Preferably, the mass space velocity of the feed liquid of the organosilicon high boiling point stock solution is 0.01 to 10 h -1 ; Preferably, the cooling temperature is -15°C to -2°C.

9. The method according to any one of claims 4 to 8, characterized in that: The organosilicon high boiling point stock solution and hydrogen are first introduced into a preheating mixer for preheating and mixing, and then the mixed stream is introduced into a fixed bed reactor; Preferably, the preheating temperature is 300-400°C.

10. The method according to any one of claims 4 to 9, characterized in that: During the continuous catalytic cracking reaction and cooling process, the reaction materials are sent to an online analysis unit for synchronous detection and analysis of the material composition.

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