A method for treating high-boiling substances in the heavy intermediate stream of dimethyldichlorosilane production

Abstract

The present invention provides a method for treating high-boiling products in a heavy intermediate stream produced by dimethyldichlorosilane. The method comprises: subjecting the high-boiling products containing Si-Si and Si-C bonds in the heavy intermediate stream produced by dimethyldichlorosilane to a hydrocracking reaction under the action of a catalyst, and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane, respectively. The catalyst is a non-precious metal@molecular sieve bifunctional encapsulated catalyst formed by encapsulating non-precious metal nanoparticles in a silicon-aluminum molecular sieve. The method has a simple operating process, mild reaction conditions, a recyclable catalyst, a high conversion rate, and realizes high-value utilization of the high-boiling products in the heavy intermediate stream.

Description

Technical Field

[0001] The invention relates to the technical field of organosilicon monomer production, and in particular to a method for treating high-boiling substances in a heavy intermediate stream of dimethyldichlorosilane production. Background Art

[0002] Currently, organosilicon materials, due to their excellent dielectric properties, high-temperature resistance, weather resistance, oxidation resistance, and physiological inertness, are widely used in aerospace, military technology, construction, chemistry, electronics, and medicine. They have become a new chemical system that has established a significant position in the national economy, earning them the reputation of "industrial MSG." Methylchlorosilanes are crucial platform raw materials for the synthesis of organosilicon materials and are a key indicator of a country's organosilicon industry development. Methylhydrochlorosilane monomers include monomethylhydrodichlorosilane [CH3-SiH-Cl2, boiling point 40-45°C] and dimethylhydromonochlorosilane [(CH3)2-SiH-Cl, boiling point 34-36°C]. Their terminal Si-H active hydrogen bonds offer unique advantages for further utilization. For example, Si-H bonds readily add to C=C bonds in organic compounds, enabling the preparation of various carbon-functional silanes, long-chain alkyl silanes, and reactive silicone oils. Si-C bonds can also link Si-O chains, forming bridging agents that bind polysiloxanes to organic polymers. Currently, the 3-5% methylhydrochlorosilane produced by the direct process for producing dimethyldichlorosilane is far from meeting market demand. Therefore, it is urgent to develop a method for preparing methylhydrochlorosilane monomers.

[0003] US4966986A discloses a method for preparing methylhydrochlorosilane monomers by a fluidized bed reaction. In the fluidized bed reaction, silicon powder and copper powder are mixed, first treated with HCl under heating conditions, and then CH3Cl-H2 is introduced for reaction. The resulting product contains approximately 39% monomethylhydrodichlorosilane [CH3-SiH-Cl2] and approximately 14-22% dimethylhydromonochlorosilane [(CH3)2-SiH-Cl]. However, the yield of the main product dimethyldichlorosilane [(CH3)2-Si-Cl2] in this process is low.

[0004] US6077967A discloses a method for preparing dimethylhydrochlorosilane monomer using trimethylchlorosilane and methylhydrodichlorosilane as raw materials, wherein the catalyst used in the method is anhydrous aluminum chloride. CN16803971A also discloses a method for preparing dimethylhydrochlorosilane using methylhydrodichlorosilane and trimethylchlorosilane as raw materials, reacting at 250-400°C in a two-stage fixed-bed reactor in the presence of an AlCl3 catalyst. However, the AlCl3 catalyst used is prone to sublimation during the reaction, resulting in the loss of its active centers, rapid catalyst deactivation, and poor cyclic stability.

[0005] US5646326A discloses that Pt / C or Ru / Al2O3 is used as a catalyst and dimethyldichlorosilane is used as a raw material, with conversion rates of 3.9% and 14.8% respectively. For the two catalysts, the products of (CH3)2-SiH-Cl and CH3-SiH-Cl2 account for 40.8% and 52.0%, 27.2% and 49.5% respectively.

[0006] CN1091136A discloses a method for reacting dimethyldichlorosilane with methylhydrogendichlorosilane or methylsilane in the presence of a catalyst. The disadvantage of this method is that the catalyst having such a silicic acid structure is difficult to prepare and is expensive.

[0007] CN106632447A discloses a two-stage fixed-bed process for preparing dimethyldichlorosilane using dimethyldichlorosilane as a raw material, hydrogen as a cracking gas, Pt, Pd, and Ni bimetallic active components, and activated carbon as a carrier. The reaction temperature is 200-500°C. The process is complex, the catalyst uses a high loading of the metal active component of approximately 5-15%, and the single-pass conversion rate of dimethyldichlorosilane is low.

[0008] From the above analysis, we can see that the preparation of dimethylhydrochlorosilane is technically difficult, the catalyst cost is high, and the operation process is complex. Furthermore, the treatment of high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production is difficult and wastes resources.

[0009] Therefore, there is an urgent need to develop a method for converting high-boiling products from the heavy intermediate stream into dimethylhydrochlorosilane. Summary of the Invention

[0010] In view of the problems existing in the prior art, the present invention provides a method for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production, that is, providing ... n The resource utilization approach of high-boiling-point products with (n=3 to 8 natural numbers) bonds not only solves environmental problems, but also reduces the raw material cost of methylhydrochlorosilane monomer production, and simultaneously realizes simple and efficient preparation of methylhydrochlorosilane monomer.

[0011] To achieve this object, the present invention adopts the following technical solutions:

[0012] The present invention provides a method for treating high-boiling products in a heavy intermediate stream of dimethyldichlorosilane production. The method comprises: subjecting the high-boiling products containing Si-Si and Si-C bonds in the heavy intermediate stream of dimethyldichlorosilane production to a hydrocracking reaction under the action of a catalyst, and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane respectively;

[0013] The catalyst is a non-noble metal@molecular sieve dual-function encapsulated catalyst formed by encapsulating non-noble metal nanoparticles in a silicon-aluminum molecular sieve.

[0014] The method provided by the present invention uses a non-precious metal@molecular sieve bifunctional encapsulated catalyst formed by encapsulating non-precious metal nanoparticles in a silicon-aluminum molecular sieve, wherein the non-precious metal serves as an active component, capable of hydrogenating and cracking high-boiling products containing Si-Si and Si-C bonds in the heavy intermediate stream. The molecular sieve carrier can provide acidic cracking sites, thereby improving the reaction conversion rate and the yield of methylhydrochlorosilane monomer.

[0015] The high boiling products in the heavy refinery interstream section of the present invention refer to the high boiling products separated by the heavy refinery separation tower during the production of dimethyldichlorosilane, and have a boiling point of 70 to 120°C.

[0016] Preferably, the high boiling products in the heavy intermediate stream contain disilane and Si-C n A mixture of bond structures, wherein n is selected from a natural number of 3 to 8, for example, 3, 4, 5, 6, 7 or 8.

[0017] The Si-Si mentioned in the present invention refers to a compound containing a Si-Si bond. There is no special restriction on the groups connected by other bonds between the two silicon atoms. For example, it can be any one of an alkyl group, a hydrogen atom, a chlorine atom or an alkenyl group, or a combination of at least two of them. n The mixture of bond structures refers to a structure in which an alkyl group and / or an alkenyl group is bonded to a silicon atom.

[0018] Preferably, the high boiling products in the heavy intermediate stream section include any one or a combination of at least two of disilane, vinylsilane or acrylsilane, wherein typical but non-limiting combinations are a combination of disilane and vinylsilane, a combination of disilane and acrylsilane, etc.

[0019] Preferably, the content of Si-Si compounds in the high-boiling material in the heavy intermediate stream is 20 to 50 wt%, for example, it can be 20 wt%, 24 wt%, 27 wt%, 30 wt%, 34 wt%, 37 wt%, 40 wt%, 44 wt%, 47 wt% or 50 wt%, etc., but is not limited to the listed values, and other values not listed within this range are also applicable.

[0020] Preferably, the high boiling materials in the heavy refined intermediate stream contain Si-C n The content of the bond (n = a natural number of 3 to 8) compound is 10 to 35 wt%, for example, it can be 10 wt%, 13 wt%, 15 wt%, 20 wt%, 28 wt%, 31 wt% or 35 wt%, etc., but is not limited to the listed values, and other unlisted values within this range are also applicable.

[0021] Preferably, the high boiling products in the heavy refined interflow section include any of (CH3)3-Si-Si-(CH3)3, (CH3)3-Si-SiCl-(CH3)2, (CH3)2-SiCl-SiCl-(CH3)2, CH3-SiCl2-SiCl2-CH3, CH3-CH2-SiCl-(CH3)2, CH3-SiCl2-CH2-Cl, CH3-SiCl2-CH2-CH=CH2, CH3-SiCl2-CH2-CH2-CH2-Cl, (CH3)2-SiCl-CH2-CH=CH2, (CH3)2-CH-CH3SiCl-CH-(CH3)2 or (CH3)3-C-SiCl-(CH3)2 The invention refers to a combination of one or at least two of the above, wherein typical but non-limiting combinations are the combination of (CH3)3-Si-Si-(CH3)3 and (CH3)3-Si-SiCl-(CH3)2, the combination of CH3-CH2-SiCl-(CH3)2 and CH3-SiCl2-CH2-Cl, the combination of CH3-SiCl2-CH2-CH=CH2 and CH3-SiCl2-CH2-CH2-CH2-Cl, the combination of (CH3)3-C-SiCl-(CH3)2 and (CH3)3-Si-CH2-Si-(CH3)3, the combination of (CH3)3-Si-Si-(CH3)3 and (CH3)2-CH-CH3SiCl-CH-(CH3)2, and the like.

[0022] Preferably, the single-pass dosage of the catalyst is 1 to 10 wt% of the high-boiling substances containing Si-Si and Si-C bonds in the heavy intermediate stream, for example, it can be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt% or 10 wt%, etc., but is not limited to the listed values, and other values not listed within this range are also applicable.

[0023] Preferably, the temperature of the hydrocracking reaction is 200-350°C, for example, it can be 200°C, 217°C, 234°C, 250°C, 267°C, 284°C, 300°C, 317°C, 334°C or 350°C, but is not limited to the listed values, and other unlisted values within this range are also applicable.

[0024] Preferably, the hydrogen pressure of the hydrocracking reaction is 3.0 to 6.0 MPa, for example, 3.0 MPa, 3.34 MPa, 3.67 MPa, 4 MPa, 4.34 MPa, 4.67 MPa, 5 MPa, 5.34 MPa, 5.67 MPa or 6.0 MPa, but is not limited to the listed values, and other unlisted values within the range are also applicable.

[0025] Preferably, the hydrocracking reaction time is 1 to 4 hours, for example, 1 hour, 2 hours, 3 hours or 4 hours, etc., but is not limited to the listed values, and other values not listed within the range are also applicable.

[0026] Preferably, the hydrocracking reaction is carried out under stirring conditions.

[0027] The hydrocracking reaction of the present invention does not impose any particular limitation on the stirring speed. The speed varies according to the production output. Any stirring speed known to those skilled in the art that can be used to uniformly mix the reaction materials can be used. For example, in the pilot stage, it can be 300 to 600 r / min.

[0028] Preferably, the catalyst preparation method includes a molecular sieve crystallization method or a solid phase melting method.

[0029] Preferably, the molecules in the catalyst are sieved from any one of the topological structures of MFI, FAU, BEA*, MWW, TON or MOR.

[0030] Preferably, the molecular sieve is a hydrogen-type molecular sieve.

[0031] Preferably, the molecular sieve is selected from any one of ZSM-5 molecular sieve, Y molecular sieve, Beta molecular sieve, MCM-49 molecular sieve or ZSM-22 molecular sieve.

[0032] Preferably, the silicon-aluminum ratio Si2O3 / Al2O3 in the molecular sieve is 20:1 to 200:1, for example, it can be 20:1, 50:1, 100:1, 120:1, 150:1, 180:1 or 200:1, but is not limited to the listed values, and other unlisted values within this range are also applicable.

[0033] Preferably, the non-noble metal in the catalyst is selected from any one or a combination of at least two of Ni, Co, Mo, Cu, Zn, Fe or W, wherein typical but non-limiting combinations are a combination of Ni and W, a combination of Fe and Mo, a combination of Ni and Fe, a combination of Co and Mo, a combination of Zn and Cu, and the like.

[0034] Preferably, the content of non-precious metals in the catalyst is 1.0 to 5.0 wt%, for example, it can be 1.0 wt%, 1.45 wt%, 1.89 wt%, 2.34 wt%, 2.78 wt%, 3.23 wt%, 3.67 wt%, 4.12 wt%, 4.56 wt% or 5.0 wt%, etc., but is not limited to the listed values, and other unlisted values within this range are also applicable.

[0035] Preferably, the particle size of the non-precious metal in the catalyst is 1 to 10 nm, for example, it can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm or 10 nm, but is not limited to the listed values. Other values not listed within this range are also applicable.

[0036] Preferably, the method comprises: subjecting the high-boiling substances containing Si-Si and Si-C bonds in the heavy intermediate stream of dimethyldichlorosilane production to a hydrocracking reaction under the action of a catalyst at 200 to 350° C., a hydrogen pressure of 3.0 to 6.0 MPa, and a speed of 300 to 600 r / min for 1 to 4 hours, and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane, respectively.

[0037] The single-pass dosage of the catalyst is 2 to 10 wt% of high-boiling substances containing Si-Si and Si-C bonds in the heavy fine interflow section. The catalyst is a non-precious metal@molecular sieve bifunctional encapsulated catalyst formed by encapsulating non-precious metal nanoparticles in a silicon-aluminum molecular sieve. The content of the non-precious metal is 1.0 to 5.0 wt%, the particle size of the non-precious metal is 1 to 10 nm, and the non-precious metal is selected from any one of Ni, Co, Mo, Cu, Zn, Fe or W, or a combination of at least two thereof.

[0038] Compared with the prior art, the present invention has at least the following beneficial effects:

[0039] (1) The method provided by the present invention for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production uses a molecular sieve catalyst encapsulated with non-precious metal nanoparticles of uniform particle size to carry out a catalytic cracking reaction, and the catalyst can be recycled;

[0040] (2) The method provided by the present invention for treating high-boiling materials in the heavy intermediate stream of dimethyldichlorosilane production has high reaction conversion rate and target product yield. Under optimal conditions, the single-pass conversion rate of high-boiling materials in the heavy intermediate stream is ≥80%, and can even reach above 97%. The yield of the main product, methylhydrochlorosilane monomer, exceeds 40%, and can even reach above 55%. The yield of the secondary product, dimethyldichlorosilane, is ≥20%, and can reach above 35%.

[0041] (3) The method provided by the present invention for treating high-boiling-point products in the heavy intermediate stream of dimethyldichlorosilane production realizes higher value utilization of high-boiling-point products in the heavy intermediate stream, thereby alleviating environmental pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is the TEM analysis image of the Co@MCM-22 dual-functional encapsulated catalyst in Example 3. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0044] The present invention is further described in detail below. However, the following examples are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0045] The following specific examples and comparative examples were conducted using a plant to treat high-boiling products from a heavy intermediate stream of dimethyldichlorosilane production. GC-MS was used to analyze the composition and content of the high-boiling products, and the results are shown in Table 1.

[0046] Table 1

[0047]

[0048]

[0049] Example 1

[0050] This embodiment provides a method for treating high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane. The method comprises: mixing 30.1 g of high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane and 2.5 g of a catalyst; introducing nitrogen to replace the air three times; introducing hydrogen to 5.5 MPa and raising the temperature to 280° C.; conducting a hydrocracking reaction at 500 rpm for 2 h; and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane, respectively; cooling the reacted materials to room temperature and then removing them, separating the catalyst from the liquid product, and obtaining the product; and analyzing the specific results as shown in column A1 of Table 2.

[0051] The catalyst is a Ni@ZSM-5 catalyst, wherein the content of Ni is 3.92wt%, Si2O3 / Al2O3=100:1, and the particle size of the non-precious metal particles is 2-4nm.

[0052] The Ni@ZSM-5 catalyst was prepared by a molecular sieve crystallization method, with reference to the preparation method of Example 4 in CN111250152B except that the components and ratios were adjusted accordingly.

[0053] Example 2

[0054] This embodiment provides a method for treating high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane. The method comprises: mixing 30.1 g of high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane and 3.0 g of a catalyst; introducing nitrogen to replace the air four times; introducing hydrogen to 6.0 MPa and raising the temperature to 280° C.; conducting a hydrocracking reaction at 600 rpm for 4 hours; and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane, respectively; cooling the reacted materials to room temperature and then removing them, separating the catalyst from the liquid product to obtain the product; and the specific results are shown in column A2 of Table 2.

[0055] The catalyst is a Co@Beta catalyst, wherein the content of Co is 2.62 wt % and the ratio of Si 2 O 3 / Al 2 O 3 is 25:1, and the particle size of the non-precious metal is 0.4-0.8 nm.

[0056] The Co@Beta catalyst was prepared by a solid phase melt crystallization method, with reference to the preparation method of Example 3 in CN110860309B except that the components and ratios were adjusted accordingly.

[0057] Example 3

[0058] This embodiment provides a method for treating high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane. The method comprises: mixing 30.5 g of high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane and 2.0 g of a catalyst; introducing nitrogen to replace air four times; introducing hydrogen to 4.5 MPa and heating to 280° C.; conducting a hydrocracking reaction at 600 rpm for 3 hours; cooling the reacted material to room temperature and then removing it; separating the catalyst from the liquid product; and obtaining products that are refined and separated to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane, respectively. Specific results are shown in column A3 of Table 2.

[0059] The catalyst is a Co@MCM-22 catalyst, wherein the content of Co is 3.63wt%, Si2O3 / Al2O3=30:1, and the particle size of the non-precious metal particles is 0.9-1.2nm.

[0060] The Co@MCM-22 catalyst was prepared by a solid phase melt crystallization method, with reference to the preparation method of Example 3 in CN110860309B except that the components and ratios were adjusted accordingly.

[0061] Example 4

[0062] This embodiment provides a method for treating high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane. The method comprises: mixing 20.1 g of high-boiling products from a heavy intermediate stream produced by dimethyldichlorosilane and 0.4 g of a catalyst; introducing nitrogen to replace the air four times; introducing hydrogen to 3.0 MPa and raising the temperature to 220° C.; conducting a hydrocracking reaction at 300 rpm for 1 hour; and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane, respectively; cooling the reacted materials to room temperature, removing them, and separating the catalyst from the liquid product to obtain the product. The specific results are shown in column A4 of Table 2.

[0063] The catalyst is a ZnCo@ZSM-22 catalyst, wherein the content of Zn is 2.12wt%, the content of Co is 2.11wt%, Si2O3 / Al2O3=80:1, and the particle size of the non-precious metal particles is 0.5-1.5nm.

[0064] The ZnCo@ZSM-22 catalyst was prepared by a solid phase melt crystallization method, with reference to the preparation method of Example 3 in CN110860309B except that the components and ratios were adjusted accordingly.

[0065] Example 5

[0066] This embodiment provides a method for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production. The method is the same as that of Example 3 except that the reaction temperature is changed to 150°C.

[0067] Example 6

[0068] This example provides a method for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production. The method is the same as Example 3 except that only 0.25 g of Co@MCM-22 catalyst is added.

[0069] Comparative Example 1

[0070] This comparative example provides a method for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production. The method is the same as Example 3 except that the Co@MCM-22 catalyst is replaced by a Co / MCM-22 catalyst prepared by an impregnation method (the Co content is 3.63wt%, Si2O3 / Al2O3=29:1).

[0071] Comparative Example 2

[0072] This comparative example provides a method for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production. The method is the same as Example 2 except that the Co@Beta catalyst is replaced by a Co / Beta molecular sieve catalyst prepared by an impregnation method (the Co content is 2.62wt%, Si2O3 / Al2O3=25:1).

[0073] Testing Method: GC-MS was used to analyze the composition of the products after the reactions in the above Examples and Comparative Examples. The conversion of high-boiling products in the heavy intermediate stream and the yield of methylchlorosilane therein were calculated. The results are shown in Table 2. A1-A6 represent Examples 1-6, respectively, and D1-D2 represent Comparative Examples 1-2.

[0074] Table 2

[0075] Liquid product yield (%) A1 A2 A3 A4 A5 A6 D1 D2 <![CDATA[(CH3)2-SiH-Cl]]> 19.8 15.8 18.1 20.3 3.6 2.1 11.7 9.4 <![CDATA[CH3-SiH-Cl2]]> 35.6 28.5 37.3 25.9 6.1 6.3 19.4 16.7 <![CDATA[(CH3)3-Si-Cl]]> 14.1 3.5 5.8 10.4 4.8 0.8 5.7 3.9 <![CDATA[(CH3)2-Si-Cl2]]> 25.4 32.4 36.0 25.0 5.1 2.1 11.9 6.1 Methylhydrochlorosilane monomer yield (%) 55.4 44.3 55.4 46.2 9.7 8.4 31.1 26.1 Conversion rate of high boiling materials in heavy intermediate stream (%) 94.9 80.2 97.2 81.6 19.6 11.3 48.7 36.1

[0076] From Table 2, we can see the following points:

[0077] (1) From Examples 1 to 4, it can be seen that the method for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production provided by the present invention achieves a single-pass conversion rate of ≥80% of high-boiling products in the heavy intermediate stream under optimal conditions by selecting a special catalyst, and the single-pass conversion rate can even reach above 97%, the yield of the main product methylhydrochlorosilane monomer exceeds 40%, and the yield of the secondary product dimethyldichlorosilane is ≥20%.

[0078] (2) From Example 1 and Example 6, it can be seen that the reaction temperature and the amount of catalyst have a great influence on the catalytic reaction effect. The present invention can better improve the reaction conversion rate, the yield of the main product methylhydrochlorosilane monomer and the yield of the secondary product dimethyldichlorosilane by further optimizing the reaction temperature and the amount of catalyst within a specific range;

[0079] (3) From Example 2 and Comparative Example 2, and Example 3 and Comparative Example 1, it can be seen that the non-precious metal@molecular sieve bifunctional encapsulated catalyst selected in the present invention has a higher conversion rate and target product yield than the non-precious metal / molecular sieve bifunctional catalyst prepared by the impregnation method.

[0080] In summary, the method provided by the present invention for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production can respectively obtain methylhydrochlorosilane monomer and dimethyldichlorosilane, and the reaction conditions are mild, and the catalyst can be recycled, thereby realizing high-value utilization of high-boiling products in the heavy intermediate stream.

[0081] The applicant declares that the present invention is intended to illustrate the detailed structural features of the present invention through the above-described embodiments, but the present invention is not limited to the above-described detailed structural features. This does not mean that the present invention must rely on the above-described detailed structural features in order to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent replacements for selected components, additions of auxiliary components, and selection of specific embodiments, etc., fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for treating high-boiling products in the heavy intermediate stream of dimethyldichlorosilane production, characterized in that: The method comprises: performing a hydrocracking reaction on high-boiling substances containing Si-Si and Si-C bonds in a heavy intermediate stream of dimethyldichlorosilane production under the action of a catalyst, and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane respectively; The high boiling products in the heavy refined intermediate flow section are disilane and Si-C containing Si-Si bond structure. n A mixture of bond structures, wherein n is selected from a natural number from 3 to 8; The catalyst is a Ni@ZSM-5 catalyst, a Co@Beta catalyst, a Co@MCM-22 catalyst or a ZnCo@ZSM-22 catalyst; The Ni@ZSM-5 catalyst was prepared by a molecular sieve crystallization method, wherein the Ni content was 3.92 wt %, Si2O3 / Al2O3=100:1, and the particle size of the non-precious metal particles was 2-4 nm; The Co@Beta catalyst was prepared by solid-phase melt crystallization, wherein the Co content was 2.62 wt%, Si2O3 / Al2O3=25:1, and the particle size of the non-precious metal particles was 0.4-0.8 nm; The Co@MCM-22 catalyst was prepared by solid-phase melt crystallization, wherein the Co content was 3.63 wt%, Si2O3 / Al2O3=30:1, and the particle size of the non-precious metal particles was 0.9-1.2 nm; The ZnCo@ZSM-22 catalyst was prepared by a solid-phase melt crystallization method, wherein the Zn content was 2.12 wt %, the Co content was 2.11 wt %, Si2O3 / Al2O3=80:1, and the particle size of the non-precious metal particles was 0.5-1.5 nm; The single-pass dosage of the catalyst is 1-10 wt% of the high-boiling substances containing Si-Si and Si-C bonds in the heavy intermediate stream; The temperature of the hydrocracking reaction is 200-350°C.

2. The method according to claim 1, characterized in that The hydrogen pressure of the hydrocracking reaction is 3.0-6.0 MPa.

3. The method according to claim 1, characterized in that The hydrocracking reaction time is 1 to 4 hours.

4. The method according to claim 1, wherein The method comprises: subjecting a high-boiling substance containing Si-Si and Si-C bonds in a heavy intermediate stream of dimethyldichlorosilane production to a hydrocracking reaction under the action of a catalyst at 200-350° C. and a hydrogen pressure of 3.0-6.0 MPa for 1-4 hours, and refining and separating the obtained reaction materials to obtain methylhydrochlorosilane monomer and dimethyldichlorosilane respectively; The single-pass dosage of the catalyst is 2-10 wt% of the high-boiling substances containing Si-Si and Si-C bonds in the heavy intermediate stream section, and the catalyst is Ni@ZSM-5 catalyst, Co@Beta catalyst, Co@MCM-22 catalyst or ZnCo@ZSM-22 catalyst; The Ni@ZSM-5 catalyst was prepared by a molecular sieve crystallization method, wherein the Ni content was 3.92 wt %, Si2O3 / Al2O3=100:1, and the particle size of the non-precious metal particles was 2-4 nm; The Co@Beta catalyst was prepared by solid-phase melt crystallization, wherein the Co content was 2.62 wt%, Si2O3 / Al2O3=25:1, and the particle size of the non-precious metal particles was 0.4-0.8 nm; The Co@MCM-22 catalyst was prepared by solid-phase melt crystallization, wherein the Co content was 3.63 wt%, Si2O3 / Al2O3=30:1, and the particle size of the non-precious metal particles was 0.9-1.2 nm; The ZnCo@ZSM-22 catalyst is prepared by a solid-phase melt crystallization method, wherein the Zn content is 2.12wt%, the Co content is 2.11wt%, Si2O3 / Al2O3=80:1, and the particle size of the non-precious metal particles is 0.5~1.5nm.

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