Composite adsorbent for deep impurity removal of organosilicon monomer feed gas and preparation method of composite adsorbent

Abstract

The invention relates to the technical field of chemical gas purification, and discloses a composite adsorbent for deep impurity removal of organosilicon monomer feed gas, which comprises the following components: hierarchical porous activated carbon, a metal organic framework material, mesoporous silicon-aluminum oxide, boron-containing silica gel and an auxiliary agent. The invention relates to a preparation method of a composite adsorbent for deep impurity removal of organic silicon monomer feed gas. The preparation method comprises the following steps: (1) respectively preparing or providing hierarchical porous activated carbon, a metal organic framework material, a mesoporous silicon-aluminum oxide, boron-containing silica gel and an auxiliary agent; (2) mechanically mixing the boron-containing silica gel prepared by the method in claim 6 with other components in proportion; and (3) granulating, forming and roasting the mixed material to obtain the composite adsorbent. Compared with the prior art, the invention provides the composite adsorbent which is large in adsorption capacity, high in selectivity, good in mechanical strength and suitable for deep impurity removal of organic silicon monomer raw material gas, and the preparation method of the composite adsorbent.

Description

Technical Field

[0001] This invention relates to the field of chemical gas purification technology, specifically to a composite adsorbent for deep purification of organosilicon monomer raw material gas and its preparation method. Background Technology

[0002] Organosilicon monomers (such as methylchlorosilane) are core raw materials for the production of silicone oils, silicone rubbers, silicone resins, and other organosilicon products. They are typically synthesized via the Rochow direct method, which involves reacting silicon powder and chloromethane in the presence of a catalyst. This reaction requires extremely high purity of the feed gas. Trace amounts of impurities such as phosphorus (P), arsenic (As), and sulfur (S) in the feed gas can poison the catalyst, significantly reducing reaction selectivity, shortening catalyst life, and affecting the quality of downstream products.

[0003] Currently, adsorption is commonly used in industry to purify feed gases. Commonly used adsorbents include activated carbon, molecular sieves, alumina, and silica gel. However, these traditional adsorbents generally suffer from low adsorption capacity, poor selectivity, and insufficient removal efficiency for trace impurities, making it difficult to meet the stringent requirements of modern organosilicon industry for deep purification of feed gases. Especially when multiple impurities with similar molecular structures and different polarities coexist, a single adsorbent often struggles to achieve synergistic deep removal.

[0004] Metal-organic frameworks (MOFs) have shown great potential in gas adsorption and separation due to their extremely high specific surface area, tunable pore structure, and surface chemistry. However, their difficult molding, poor hydrothermal stability, and high cost limit their industrial applications. How to combine the high adsorption performance of MOFs with the mechanical strength, stability, and cost advantages of traditional materials to develop a composite adsorbent capable of synergistically and deeply removing multiple impurities is a pressing technical problem to be solved in this field. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned technical difficulties and provide a composite adsorbent with large adsorption capacity, high selectivity, good mechanical strength, and suitable for deep purification of organosilicon monomer feed gas, and its preparation method.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0007] A composite adsorbent for deep purification of organosilicon monomer feed gas comprises the following components: multi-level porous activated carbon, metal-organic framework material, mesoporous silica-alumina oxide, boron-containing silica gel, and additives.

[0008] Furthermore, the composite adsorbent comprises the following components in parts by weight: 60-85% multi-level porous activated carbon, 10-30% metal-organic framework material, 5-15% mesoporous silica-alumina oxide, 5-15% boron-containing silica gel, and 5-15% additives.

[0009] Furthermore, the composite adsorbent comprises the following components in parts by weight: 75% multi-level porous activated carbon, 20% metal-organic framework material, 10% mesoporous silica-alumina oxide, 10% boron-containing silica gel, and 10% additives.

[0010] Furthermore, the specific surface area of ​​the multi-level porous activated carbon is 800-1500 m². 2 / g, pore volume 0.8-1.8cm 3 / g, of which macropores (pore size > 50nm) account for 15-30%, mesopores (pore size 2-50nm) account for 50-70%, and micropores (pore size < 2nm) account for 20-30%.

[0011] Furthermore, the metal-organic framework material is one of ZIF-8, UIO-66, and MIL-100(Fe).

[0012] Furthermore, the additive is a rare earth oxide, and the rare earth oxide is at least one of La2O3 and CeO2.

[0013] Furthermore, the silicon-aluminum molar ratio of the mesoporous silicon-aluminum oxide is (10-30):1.

[0014] Furthermore, the method for using boron-containing silica gel includes the following steps:

[0015] (a) Dissolve tetraethyl orthosilicate and boric acid in an aqueous ethanol solution at a molar ratio of 1:(0.3-0.5);

[0016] (b) Under acidic conditions of pH 4-5, a hydrolysis-condensation reaction is carried out to form a sol;

[0017] (c) The sol obtained in step (2) is aged and dried to obtain the boron-containing silica gel.

[0018] A method for preparing a composite adsorbent for deep purification of organosilicon monomer feed gas includes the following steps:

[0019] (1) Prepare or provide multi-level porous activated carbon, metal-organic framework materials, mesoporous silica-alumina oxides, boron-containing silica gel and additives respectively;

[0020] (2) The boron-containing silica gel prepared by the method of claim 6 is mechanically mixed with other components in proportion;

[0021] (3) The mixed materials are granulated, shaped and calcined to obtain the composite adsorbent.

[0022] Furthermore, in step (3), the calcination is carried out under an inert atmosphere, the calcination temperature is 300-500℃, and the calcination time is 2-4 hours.

[0023] The advantages of this invention compared to the prior art are:

[0024] 1. This invention ingeniously combines five functional components to achieve synergistic adsorption. Multi-level porous activated carbon serves as the main component, providing a large specific surface area and physical adsorption capacity; MOF materials utilize their precise pores and metal sites for specific adsorption; mesoporous silica-alumina oxides utilize their surface acidity to adsorb polar molecules; boron-containing silica gel enhances selectivity through surface modification; and rare earth additives are specifically designed for the chemical removal of the most difficult-to-treat phosphorus and arsenic impurities. This multi-mechanism synergistic effect achieves simultaneous and deep removal of various trace impurities.

[0025] 2. This invention uses multi-level porous activated carbon as a supporting framework, ensuring the mechanical strength and stability of the composite material and overcoming the shortcomings of pure MOF materials, such as poor formability and easy pulverization. The abundant multi-level pores ensure efficient diffusion and mass transfer of impurity molecules.

[0026] 3. The preparation method of this invention mainly includes mechanical mixing and calcination. The process is simple, easy to operate, and has low equipment requirements, making it very suitable for large-scale industrial production. Detailed Implementation

[0027] In the description of this invention, unless otherwise stated, "a plurality of" means two or more. Furthermore, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

[0028] The present invention will now be described in further detail with reference to the embodiments.

[0029] Example 1

[0030] A composite adsorbent for deep purification of organosilicon monomer feed gas comprises the following components in parts by weight: 60% multi-level porous activated carbon, 10% metal-organic framework material, 5% mesoporous silica alumina oxide, 5% boron-containing silica gel, and 5% additives.

[0031] The specific surface area of ​​the multi-level porous activated carbon is 800 m². 2 / g, pore volume 0.8cm 3 / g, of which macropores (pore size > 50nm) account for 15%, mesopores (pore size 2-50nm) account for 50%, and micropores (pore size < 2nm) account for 20%.

[0032] The metal-organic framework material is ZIF-8.

[0033] The additive is a rare earth oxide, specifically La2O3.

[0034] The silicon-to-aluminum molar ratio of the mesoporous silicon-aluminum oxide is 10:1.

[0035] The method for producing boron-containing silica gel includes the following steps: (a) dissolving tetraethyl orthosilicate and boric acid in an ethanol aqueous solution at a molar ratio of 1:0.3; (b) carrying out a hydrolysis-condensation reaction under acidic conditions of pH 4-5 to form a sol; and (c) aging and drying the sol obtained in step (2) to obtain the boron-containing silica gel.

[0036] A method for preparing a composite adsorbent for deep purification of organosilicon monomer feed gas includes the following steps:

[0037] (1) Prepare or provide multi-level porous activated carbon, metal-organic framework materials, mesoporous silica-alumina oxides, boron-containing silica gel and additives respectively;

[0038] (2) The boron-containing silica gel prepared by the method of claim 6 is mechanically mixed with other components in proportion;

[0039] (3) The mixed materials are granulated, shaped and calcined to obtain the composite adsorbent. The calcination is carried out under an inert atmosphere at a temperature of 300°C for 2 hours.

[0040] Example 2

[0041] A composite adsorbent for deep purification of organosilicon monomer feed gas comprises the following components in parts by weight: 85% multi-level porous activated carbon, 30% metal-organic framework material, 15% mesoporous silica alumina oxide, 15% boron-containing silica gel, and 15% additives.

[0042] The specific surface area of ​​the multi-level porous activated carbon is 1500 m². 2 / g, pore volume 1.8cm 3 / g, of which macropores (pore size > 50nm) account for 30%, mesopores (pore size 2-50nm) account for 70%, and micropores (pore size < 2nm) account for 30%.

[0043] The metal-organic framework material is MIL-100(Fe).

[0044] The additive is a rare earth oxide, specifically CeO2.

[0045] The silicon-aluminum molar ratio of the mesoporous silicon-aluminum oxide is 30:1.

[0046] The method for producing boron-containing silica gel includes the following steps: (a) dissolving tetraethyl orthosilicate and boric acid in an ethanol aqueous solution at a molar ratio of 1:0.5; (b) carrying out a hydrolysis-condensation reaction under acidic conditions of pH 4-5 to form a sol; and (c) aging and drying the sol obtained in step (2) to obtain the boron-containing silica gel.

[0047] A method for preparing a composite adsorbent for deep purification of organosilicon monomer feed gas includes the following steps:

[0048] (1) Prepare or provide multi-level porous activated carbon, metal-organic framework materials, mesoporous silica-alumina oxides, boron-containing silica gel and additives respectively;

[0049] (2) The boron-containing silica gel prepared by the method of claim 6 is mechanically mixed with other components in proportion;

[0050] (3) The mixed materials are granulated, shaped and calcined to obtain the composite adsorbent. The calcination is carried out under an inert atmosphere, at a temperature of 500°C and a time of 4 hours.

[0051] The present invention and its embodiments have been described above, and this description is not restrictive. If those skilled in the art are inspired by this description and design similar embodiments without departing from the spirit of the invention, such embodiments should fall within the protection scope of the present invention.

Claims

1. A composite adsorbent for deep purification of organosilicon monomer feed gas, characterized in that, It includes the following components: multi-level porous activated carbon, metal-organic framework material, mesoporous silica-alumina oxide, boron-containing silica gel, and additives.

2. The composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 1, characterized in that, It comprises the following components in parts by weight: 60-85% multi-level porous activated carbon, 10-30% metal-organic framework material, 5-15% mesoporous silica-alumina oxide, 5-15% boron-containing silica gel, and 5-15% additives.

3. The composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 2, characterized in that, It comprises the following components by weight: 75% multi-level porous activated carbon, 20% metal-organic framework material, 10% mesoporous silica-alumina oxide, 10% boron-containing silica gel, and 10% additives.

4. The composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 1, characterized in that: The specific surface area of ​​the multi-level porous activated carbon is 800-1500 m². 2 / g, pore volume 0.8-1.8cm 3 / g, of which macropores (pore size > 50nm) account for 15-30%, mesopores (pore size 2-50nm) account for 50-70%, and micropores (pore size < 2nm) account for 20-30%.

5. The composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 1, characterized in that: The metal-organic framework material is one of ZIF-8, UIO-66, and MIL-100(Fe).

6. The composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 1, characterized in that: The additive is a rare earth oxide, and the rare earth oxide is at least one of La2O3 and CeO2.

7. The composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 1, characterized in that: The silicon-aluminum molar ratio of the mesoporous silicon-aluminum oxide is (10-30):

1.

8. The composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 1, characterized in that: The method for using boron-containing silica gel includes the following steps: (a) Dissolve tetraethyl orthosilicate and boric acid in an aqueous ethanol solution at a molar ratio of 1:(0.3-0.5); (b) Under acidic conditions of pH 4-5, a hydrolysis-condensation reaction is carried out to form a sol; (c) The sol obtained in step (2) is aged and dried to obtain the boron-containing silica gel.

9. A method for preparing a composite adsorbent for deep purification of organosilicon monomer feed gas, characterized in that, Includes the following steps: (1) Prepare or provide multi-level porous activated carbon, metal-organic framework materials, mesoporous silica-alumina oxides, boron-containing silica gel and additives respectively; (2) The boron-containing silica gel prepared by the method of claim 6 is mechanically mixed with other components in proportion; (3) The mixed materials are granulated, shaped and calcined to obtain the composite adsorbent.

10. The method for preparing a composite adsorbent for deep purification of organosilicon monomer feed gas according to claim 9, characterized in that: In step (3), the calcination is carried out under an inert atmosphere, the calcination temperature is 300-500℃, and the calcination time is 2-4 hours.