Organic amine grafted organic silicon high-boiling residue catalyst containing primary and secondary amino groups and organic silicon high-boiling residue catalytic cracking process
By grafting the organic amine containing secondary amino groups with high boiling materials of organic silicon, an efficient cracking catalyst was prepared, which solved the problems of serious catalyst loss and high energy consumption in the prior art, and achieved efficient cracking of high boiling materials of organic silicon and the generation of highly selective products.
Patent Information
- Application Number
- CN202510360003.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-25
- Publication Date
- 2025-06-27
AI Technical Summary
The prior art has problems such as severe catalyst loss, high energy consumption, harsh operating conditions, high equipment investment and operating costs, and difficult to achieve continuous operation during the cracking process of silicone high boiling substances.
By grafting the organic amine containing a secondary amino group with a high boiling substance of the silicone, a high relative molecular mass cracking catalyst is prepared, and a catalytic cracking reaction is carried out under suitable temperature and conditions.
It has achieved efficient cracking of high-boiler organic silicone, with a cracking rate of high-boiler of up to 50%, and a selectivity of dimethyldichlorosilane can reach more than 50%, and has the advantages of high recycling, low waste, low environmental impact and easy industrialization.
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Figure CN120209013A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for preparing a cracking catalyst for organosilicon high-boiling substances by grafting an organosilicon high-boiling substance with an organic amine containing primary and secondary amino groups. Background Art
[0002] Organosilicon refers to a compound containing a carbon-silicon bond and at least one organic group directly connected to a silicon atom. It has characteristics such as heat resistance, weather resistance, electrical insulation, low surface tension, and low surface energy, and can be used as a raw material for single-crystalline silicon and polycrystalline silicon products in emerging energy sources - photovoltaic energy. Organosilicon has been rapidly and widely applied in various industries and sectors of the national economy, such as military, electronics, electrical, textile, automotive, machinery, chemical, light industry, leather, paper, paint, metal, construction, aviation, and medical treatment.
[0003] With the continuous development of the chemical industry, organosilicon compounds have been widely applied in multiple fields due to their unique chemical properties. However, in the production and processing processes, the presence of organosilicon high-boiling substances poses challenges to the purification and utilization of products.
[0004] Organosilicon high-boiling substances are by-products in the production of dimethyldichlorosilane monomers by the "direct method", composed of elements such as silicon, carbon, hydrogen, and chlorine, and are rich in high-value structural compounds such as Si-Si bonds, C-Si bonds, H-Si bonds, O-Si bonds, and Cl-Si bonds. With the rapid development of the organosilicon industry, the output of methylchlorosilane monomers is increasing, and the production of high-boiling substances is also increasing accordingly.
[0005] The components of organosilicon high-boiling substances are mainly compounds containing at least two adjacent Si atoms. When heated to a certain temperature, the Si-Si bond breaks to generate silane monomers with lower molecular weights. Therefore, high-boiling substances can be cracked by high-temperature pyrolysis. The American company MOHLERD gasifies organosilicon high-boiling substances and cracks them in a stainless steel tubular reactor at 525°C and atmospheric pressure to obtain silane monomers. The disadvantages of this method are that the yield of methylchlorosilane is not high, solid particles from organosilicon high-boiling substances will accumulate on the inner wall of the reaction tube after a long reaction, and at the same time, coking will occur due to the long-term high-temperature state of the reaction tube.
[0006] Aluminum chloride has good cracking and disproportionation effects, can promote the breaking of Si-Si bonds and C-Si bonds, and also helps with the rearrangement of chlorine atoms and methyl groups on different silicon atoms. When used as a catalyst, it can cut the Si-Si bonds and C-Si bonds in high-boiling substances to generate small-molecule organosilicon monomers. Its advantages include: simple physical properties, rich sources, and low catalyst cost. However, when using aluminum chloride as a catalyst, the reaction temperature is relatively high, generally between 300 and 500 °C, and the energy consumption is high. Aluminum chloride is prone to sublimation and loss, and the catalytic effect will continuously decrease. Especially at higher temperatures, the loss of aluminum chloride is more serious. To prevent the sublimation and loss of aluminum chloride, the reaction is generally carried out under high pressure, which makes the operating conditions very harsh. At the same time, aluminum chloride belongs to Lewis acid and has strong corrosiveness, which improves the requirements for equipment, increases equipment investment and operating costs, and also affects the safety of operation. In addition, this technology can basically not be continuously operated and can only be batch-operated, resulting in limited production capacity.
[0007] Using tertiary amines, N,N-dimethylformamide, N,N-diethylformamide, quaternary ammonium halides, quaternary phosphonium halides, etc. as catalysts, the reaction is mainly batch reaction. Its reaction conditions are mild, the reaction temperature is low, and the yield of dimethyldichlorosilane monomer is high. However, sometimes chlorides are used to introduce new organic groups, resulting in the generation of some new substances. At the same time, the catalyst is expensive and difficult to recycle and reuse.
[0008] The method for catalytic cracking of organosilicon high-boiling substances to prepare methylchlorosilane has the advantages of high catalytic activity, simple process, high safety, high selectivity for dimethyldichlorosilane, less generation of useless monomers, high conversion rate, less remaining waste, and environmental friendliness. At the same time, it has extremely high recyclability and is easy to industrialize. Summary of the Invention
[0009] The present invention mainly aims at the problems and deficiencies existing in the prior art, and discloses a method for preparing a cracking catalyst for organosilicon high-boiling substances by grafting an organosilicon high-boiling substance with an organic amine containing primary and secondary amino groups. A cracking catalyst is prepared by grafting an organosilicon high-boiling substance with an organic amine containing primary and secondary amino groups. Then, the cracking catalyst is used to catalytically crack the organosilicon high-boiling substance to convert it into a mixed product mainly composed of dimethyldichlorosilane monomers. Among them, the cracking rate of the high-boiling substance can reach more than 50%. In some preferred cases, the cracking rate of the high-boiling substance can reach more than 60%. In some preferred cases, the cracking rate of the high-boiling substance can reach more than 70%. In some preferred cases, the cracking rate of the high-boiling substance can reach more than 80%. The selectivity of dimethyldichlorosilane can reach more than 50%; in some preferred cases, the selectivity of dimethyldichlorosilane can reach more than 60%; in some preferred cases, the selectivity of dimethyldichlorosilane can reach more than 70%; in some preferred cases, the selectivity of dimethyldichlorosilane can reach more than 80%. The method for catalytically cracking organosilicon high-boiling substances to prepare methylchlorosilanes has the advantages of high catalytic activity, simple process, high safety, high selectivity of dimethyldichlorosilane, few useless monomers generated, high conversion rate, few remaining waste materials, environmental friendliness, and at the same time has extremely high recyclability and is easy to industrialize.
[0010] The present invention relates to a method for preparing a cracking catalyst for organosilicon high-boiling substances by grafting an organosilicon high-boiling substance with an organic amine containing primary and secondary amino groups, and the principle is as follows: The composition of the organosilicon high-boiling substance is as follows:
[0011] The organosilicon high-boiling substance contains a large number of silicon-chlorine bonds (Si-Cl) that can react with the amino groups in the organic amine containing primary and secondary amino groups to graft the organic amine containing primary and secondary amino groups onto the organosilicon high-boiling substance.
[0012] The amino group (-NH2) in the organic amine containing primary and secondary amino groups acts as a nucleophile to attack the silicon atom in the silicon-chlorine bond (Si-Cl) and replace the chlorine atom (-Cl). The reaction mechanism is as follows:
[0013]
[0014] In addition, the organosilicon high-boiling substance also contains various compounds containing silicon-chlorine bonds (Si-Cl), which can also react with the organic amine containing primary and secondary amino groups.
[0015] At the same time, since the selected organic amine containing primary and secondary amino groups contains multiple amino groups, it can react with the organosilicon high-boiling substance to form a cross-linked structure.
[0016] The present invention has the following advantages compared with the prior art: (1) In the present invention, the small-molecule organic amine containing primary and secondary amino groups is grafted onto the high-boiling organosilicon compound in the form of a covalent bond, increasing the relative molecular mass and boiling point of the cracking catalyst. Compared with the traditional direct use of organic amine as a catalyst, the loss of the catalyst caused by entrainment is reduced.
[0017] (2) In the present invention, the small-molecule organic amine containing primary and secondary amino groups will undergo a cross-linking reaction with the high-boiling organosilicon compound to form a solid substance. Compared with the traditional direct use of organic amine as a catalyst, the loss of the catalyst is greatly reduced, and the recycling service life of the catalyst is improved.
[0018] (3) The present invention can graft two catalysts with different catalytic activities and selectivities onto the high-boiling compound. Compared with the prior art, by molecular compounding different organoamines with catalytic activities, the cracking catalyst prepared by the present invention has high catalytic activity, high selectivity for dimethyldichlorosilane, less generation of useless monomers, high conversion rate, and less remaining waste.
[0019] (4) The present invention uses the by-product high-boiling organosilicon compound in the process of producing dimethyldichlorosilane monomer by the "direct method" as the grafting material, effectively improving the resource utilization rate. Description of the Drawings
[0020] Figure 1 It is a physical diagram of the cracking catalyst prepared in Example 1. Detailed Embodiments
[0021] The following further illustrates the present invention in conjunction with specific embodiments, but these embodiments are only used to further illustrate the present invention, rather than to limit the scope of the present invention. The specific ratios, reaction parameters, and material selections involved in the detailed embodiments are listed in this detailed embodiment for the purpose of illustrating the present invention, and are not any limitation to the present invention.
[0022] On the one hand, the present invention provides a preparation method of a grafted catalyst, including the following steps: Adding the organic amine containing primary and secondary amino groups to the high-boiling organosilicon compound, and heating to graft the organic amine containing primary and secondary amino groups onto the high-boiling organosilicon compound to prepare a cracking catalyst.
[0023] Among them, the mass ratio of the high-boiling organosilicon compound to the organic amine is 0.6 - 6:1.
[0024] Among them, the preparation temperature of the grafted cracking catalyst is 100 - 160 °C.
[0025] Among them, the organic amine containing primary and secondary amino groups includes one or more combinations of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, and pentaethylenehexamine.
[0026] On the other hand, the present invention provides a catalytic cracking process for organosilicon high boilers, comprising the following steps: Add the organosilicon high boiler into a reactor, and add the cracking catalyst described in any one of claims 1-4. Then, introduce or not introduce a cracking agent into the reactor. Control the reaction temperature at 100-230 °C, and carry out a catalytic cracking reaction under the catalytic conditions of the cracking catalyst to generate a mixed product mainly composed of dimethyldichlorosilane monomer, and separate and recover it through separation operations. At the same time, continuously introduce high boilers during the reaction.
[0027] Wherein, the mass ratio between the cracking catalyst and the high boiler is 0.1-25:100.
[0028] Wherein, the cracking reaction temperature is 100-230 °C.
[0029] Wherein, the cracking agent is one or more of methyl chloride and hydrogen chloride.
[0030] Wherein, the reactor can be one of a packed tower, a fixed bed, a fluidized bed, a stirred bed or a stirred reaction kettle.
[0031] The present invention selects an organic amine containing primary and secondary amino groups, because it can react with the silicon-chlorine bond (Si-Cl) in the organosilicon high boiler and graft it into the organosilicon high boiler.
[0032] Organosilicon high boiler is a by-product in the production of dimethyldichlorosilane monomer by the "direct method", and it contains a large amount of silicon-chlorine bonds (Si-Cl). The high boilers in the following examples are provided by Xingfa Group Hubei Xingrui Silicon Materials Co., Ltd.
[0033] The following examples are some examples of the present invention, rather than all examples. Based on the examples in the present invention, all other examples obtained by the inventor without creative labor fall within the protection scope of the present invention.
[0034] Example 1 Add the organosilicon high boiler and diethylenetriamine into a flask according to a mass ratio of 2:1, heat to 150 °C and react for 30 minutes to prepare a cracking catalyst by grafting the hydroxy-containing organic amine onto the organosilicon high boiler.
[0035] Add 150 g of organosilicon high boiler into a packed tower, and add 9.00 g of the cracking catalyst prepared above. Then, introduce a cracking agent into the packed tower, with the methyl chloride flow rate being 20 ml / min. Control the reaction temperature at 180 °C, and carry out a catalytic cracking reaction under the catalytic conditions of the cracking catalyst to generate a mixed product mainly composed of dimethyldichlorosilane monomer, and separate and recover it through separation operations. At the same time, introduce pretreated high boilers into the reaction process at a flow rate of 6.70 g / min for 30 minutes.
[0036] After calculation, the cracking rate of high-boiling silicone can reach 70%. After detection by gas chromatograph, the selectivity of dimethyldichlorosilane can reach 70%.
[0037] Example 2 Add high-boiling silicone and diethylenetriamine into a flask at a mass ratio of 2:1, heat to 150 °C and react for 30 minutes to graft the hydroxy-containing organic amine onto the high-boiling silicone to prepare a cracking catalyst.
[0038] Add 150 g of high-boiling silicone into a packed column, and add 4.50 g of the above-prepared cracking catalyst. Then introduce a cracking agent into the packed column. The flow rate of methyl chloride is 20 ml / min, and the reaction temperature is controlled at 165 °C. A catalytic cracking reaction occurs under the catalytic conditions of this cracking catalyst to generate a mixed product mainly composed of dimethyldichlorosilane monomer, which is separated and recovered through separation operations. At the same time, pretreated high-boiling substances are introduced at a flow rate of 6.70 g / min during the reaction for 30 min.
[0039] After calculation, the cracking rate of high-boiling silicone can reach 62%. After detection by gas chromatograph, the selectivity of dimethyldichlorosilane can reach 79%.
[0040] Example 3 Add high-boiling silicone and diethylenetriamine into a flask at a mass ratio of 2:1, heat to 150 °C and react for 30 minutes to graft the hydroxy-containing organic amine onto the high-boiling silicone to prepare a cracking catalyst.
[0041] Add 150 g of high-boiling silicone into a packed column, and add 2.25 g of the above-prepared cracking catalyst. Then introduce a cracking agent into the packed column. The flow rate of methyl chloride is 20 ml / min, and the reaction temperature is controlled at 150 °C. A catalytic cracking reaction occurs under the catalytic conditions of this cracking catalyst to generate a mixed product mainly composed of dimethyldichlorosilane monomer, which is separated and recovered through separation operations. At the same time, pretreated high-boiling substances are introduced at a flow rate of 6.70 g / min during the reaction for 30 min.
[0042] After calculation, the cracking rate of high-boiling silicone can reach 51%. After detection by gas chromatograph, the selectivity of dimethyldichlorosilane can reach 79%.
[0043] Example 4 Add high-boiling silicone and triethylenetetramine into a flask at a mass ratio of 2:1, heat to 150 °C and react for 30 minutes to graft the hydroxy-containing organic amine onto the high-boiling silicone to prepare a cracking catalyst.
[0044] Add 150 g of organosilicon high-boiling residues to a packed column, and add 9.00 g of the cracking catalyst prepared above. Then, introduce a cracking agent into the packed column. The flow rate of methyl chloride is 20 ml / min. Control the reaction temperature at 180 °C. Under the catalytic conditions of this cracking catalyst, a catalytic cracking reaction occurs to produce a mixed product mainly composed of dimethyldichlorosilane monomer, which is separated and recovered through separation operations. At the same time, during the reaction process, pretreated high-boiling residues are introduced at a flow rate of 6.70 g / min for 30 min.
[0045] After calculation, the cracking rate of the organosilicon high-boiling residues can reach 60%. After detection by a gas chromatograph, the selectivity of dimethyldichlorosilane can reach 67%.
[0046] Example 5 Add organosilicon high-boiling residues and tetraethylenepentamine to a flask at a mass ratio of 2:1, heat to 150 °C and react for 30 minutes to graft the hydroxy-containing organic amine onto the organosilicon high-boiling residues to prepare a cracking catalyst.
[0047] Add 150 g of organosilicon high-boiling residues to a packed column, and add 9.00 g of the cracking catalyst prepared above. Then, introduce a cracking agent into the packed column. The flow rate of methyl chloride is 20 ml / min. Control the reaction temperature at 180 °C. Under the catalytic conditions of this cracking catalyst, a catalytic cracking reaction occurs to produce a mixed product mainly composed of dimethyldichlorosilane monomer, which is separated and recovered through separation operations. At the same time, during the reaction process, pretreated high-boiling residues are introduced at a flow rate of 6.70 g / min for 30 min.
[0048] After calculation, the cracking rate of the organosilicon high-boiling residues can reach 57%. After detection by a gas chromatograph, the selectivity of dimethyldichlorosilane can reach 57%.
[0049] Example 6 Add organosilicon high-boiling residues and pentaethylenehexamine to a flask at a mass ratio of 2:1, heat to 150 °C and react for 30 minutes to graft the hydroxy-containing organic amine onto the organosilicon high-boiling residues to prepare a cracking catalyst.
[0050] Add 150 g of organosilicon high-boiling residues to a packed column, and add 9.00 g of the cracking catalyst prepared above. Then, introduce a cracking agent into the packed column. The flow rate of methyl chloride is 20 ml / min. Control the reaction temperature at 180 °C. Under the catalytic conditions of this cracking catalyst, a catalytic cracking reaction occurs to produce a mixed product mainly composed of dimethyldichlorosilane monomer, which is separated and recovered through separation operations. At the same time, during the reaction process, pretreated high-boiling residues are introduced at a flow rate of 6.70 g / min for 30 min.
[0051] After calculation, the cracking rate of the organosilicon high-boiling residues can reach 51%. After detection by a gas chromatograph, the selectivity of dimethyldichlorosilane can reach 51%.
[0052] Example 7 The silicone high-boiling components and diethylenetriamine were added to a flask at a mass ratio of 0.5:1, and heated to 150 °C for reaction for 30 minutes to graft the hydroxy-containing organic amine onto the silicone high-boiling components to prepare a cracking catalyst.
[0053] 150 g of silicone high-boiling components were added to a packed column, and 4.50 g of the above-prepared cracking catalyst was added. Then, a cracking agent was introduced into the packed column, the flow rate of methyl chloride was 20 ml / min, the reaction temperature was controlled at 180 °C, and a catalytic cracking reaction occurred under the catalytic conditions of this cracking catalyst to generate a mixed product mainly composed of dimethyldichlorosilane monomer, which was separated and recovered by separation operation. At the same time, pretreated high-boiling components were introduced at a flow rate of 6.70 g / min during the reaction for 30 min.
[0054] Calculated, the cracking rate of the silicone high-boiling components can reach 61%. Detected by a gas chromatograph, the selectivity of dimethyldichlorosilane can reach 63%.
[0055] Example 8 The silicone high-boiling components and diethylenetriamine were added to a flask at a mass ratio of 2:1, and heated to 150 °C for reaction for 30 minutes to graft the hydroxy-containing organic amine onto the silicone high-boiling components to prepare a cracking catalyst.
[0056] 150 g of silicone high-boiling components were added to a packed column, and 9.00 g of the above-prepared cracking catalyst was added. Then, a cracking agent was introduced into the packed column, the flow rate of hydrogen chloride was 20 ml / min, the reaction temperature was controlled at 180 °C, and a catalytic cracking reaction occurred under the catalytic conditions of this cracking catalyst to generate a mixed product mainly composed of dimethyldichlorosilane monomer, which was separated and recovered by separation operation. At the same time, pretreated high-boiling components were introduced at a flow rate of 6.70 g / min during the reaction for 30 min.
[0057] Calculated, the cracking rate of the silicone high-boiling components can reach 67%. Detected by a gas chromatograph, the selectivity of dimethyldichlorosilane can reach 53%.
[0058] Example 9 The silicone high-boiling components and diethylenetriamine were added to a flask at a mass ratio of 2:1, and heated to 150 °C for reaction for 30 minutes to graft the hydroxy-containing organic amine onto the silicone high-boiling components to prepare a cracking catalyst.
[0059] Add 150 g of organosilicon high-boiling substances into a fixed-bed reactor, and add 9.00 g of the above-prepared cracking catalyst. Then, introduce a cracking agent into the fixed-bed reactor. The flow rate of methyl chloride is 20 ml / min. Control the reaction temperature at 180 °C. Under the catalytic conditions of this cracking catalyst, a catalytic cracking reaction occurs to generate a mixed product mainly composed of dimethyldichlorosilane monomer, which is separated and recovered through separation operations. At the same time, during the reaction process, introduce pretreated high-boiling substances at a flow rate of 6.70 g / min for 30 min.
[0060] After calculation, the cracking rate of organosilicon high-boiling substances can reach 63%. After detection by a gas chromatograph, the selectivity of dimethyldichlorosilane can reach 67%.
[0061] Example 10 Add 150 g of organosilicon high-boiling substances into a packed tower, and add 3.00 g of diethylenetriamine. Then, introduce a cracking agent into the packed tower. The flow rate of methyl chloride is 20 ml / min. Control the reaction temperature at 180 °C. Under the catalytic conditions of this cracking catalyst, a catalytic cracking reaction occurs to generate a mixed product mainly composed of dimethyldichlorosilane monomer, which is separated and recovered through separation operations. At the same time, during the reaction process, introduce pretreated high-boiling substances at a flow rate of 6.70 g / min for 30 min.
[0062] After calculation, the cracking rate of organosilicon high-boiling substances can reach 53%. After detection by a gas chromatograph, the selectivity of dimethyldichlorosilane can reach 61%.
Claims
1. An organic amine grafted organosilicon high boiling catalyst containing primary and secondary amino groups, characterized in that: The organic amine containing primary and secondary amino groups is added into the high-boiling organosilicon and heated to make the organic amine containing primary and secondary amino groups grafted onto the high-boiling organosilicon to prepare the cracking catalyst.
2. The organic amine grafted organosilicon high boiling point catalyst containing primary and secondary amino groups according to claim 1, characterized in that: The mass ratio of the high boiling organosilicon substance to the organic amine is 0.6-6:
1.
3. The organic amine grafted organosilicon high boiling point catalyst containing primary and secondary amino groups according to claim 1, characterized in that: The preparation temperature of the grafted cracking catalyst is 100-160°C.
4. The organic amine grafted organosilicon high boiling point catalyst containing primary and secondary amino groups according to claim 1, characterized in that: The organic amine containing primary or secondary amino groups includes one or more combinations of diethylenetriamine, triethylenetetramine, tetraethylenepentamine and pentaethylenehexamine.
5. The primary and secondary amino group-containing organic amine grafted organosilicon high boiling point catalyst according to any one of claims 1 to 4, characterized in that: Small molecule organic amines containing primary and secondary amino groups react with high-boiling organic silicon products to form solid catalysts.
6. A catalytic cracking process for high-boiling organic silicon, characterized in that: The following steps are involved: Adding high-boiling organosilicon into a reactor, and adding the high-boiling organosilicon catalyst grafted with an organic amine containing primary and secondary amino groups as claimed in any one of claims 1 to 4, then introducing or not introducing a cracking agent into the reactor, a catalytic cracking reaction occurs under the catalytic conditions of the cracking catalyst, and the product is separated to obtain a mixed product mainly composed of dimethyldichlorosilane monomer.
7. The process for catalytic cracking of high-boiling organic silicon according to claim 6, characterized in that: The mass ratio of the primary and secondary amino group-containing organic amine grafted organic silicon high boiling point catalyst to the high boiling point is 0.1-25:
100.
8. The process for catalytic cracking of high-boiling organic silicon according to claim 6, characterized in that: The catalytic cracking reaction temperature is 100~230℃.
9. The process for catalytic cracking of high boiling organic silicon products according to claim 6, characterized in that: The cracking agent is one or more of methyl chloride and hydrogen chloride.
10. The process for catalytic cracking of high boiling organic silicon products according to claim 6, characterized in that: The reactor can be one of a packed tower, a solidified bed, a fluidized bed, a stirred bed or a stirred reactor.