An apparatus for preparing a nanoscale titanium oxide particle sol

Abstract

The utility model provides a kind of preparation device of nanometer titanium oxide particle sol, the preparation process of titanium oxide particle sol is controlled using full membrane method process, specific content includes: dynamic microporous ceramic membrane feed, dynamic rotation+microporous penetration, realize the high homogenization of reaction system;Dynamic ceramic membrane separates, concentrates and washes intermediate product, and the intermediate product is purified;Dynamic microporous ceramic reactor carries out on-line particle classification to reaction product, realizes the homogenization of product particle;Efficient separation alcohol and water by pervaporation membrane, realize the reuse of alcohol.The reactant is added in the device using membrane reactor D1 (dynamic rotating membrane reactor), so that the reactant is more evenly dispersed in the system, and the product particle size distribution is too wide due to local concentration being too high or too low is inhibited.

Description

Technical Field

[0001] This utility model relates to the field of nanosol technology, and in particular to an apparatus for preparing nanoscale titanium dioxide particle sol. Background Technology

[0002] The sol-gel process is one of the core technologies for preparing inorganic ceramic separation membranes (such as microfiltration (MF), ultrafiltration (UF), and nanofiltration (NF) membranes). This process typically includes four key steps: synthesis of the gel precursor, uniform deposition of the sol on a support surface, drying of the gel network, and final high-temperature sintering. Among these, the particle size distribution of the gel is the core factor determining the final membrane performance, directly related to the pore size distribution and separation efficiency. Theoretically, the narrower the particle size distribution of the gel, the more conducive it is to forming a membrane structure with uniform pore size and high separation precision.

[0003] In existing technologies, the preparation of titanium dioxide sol generally adopts the hydrolysis reaction method. This method attempts to optimize the gel particle size distribution by controlling parameters such as the type of precursor (e.g., titanate esters), precursor concentration, hydrolysis ratio (water / precursor molar ratio), reaction temperature and time, type and amount of gel solvent (e.g., nitric acid, acetic acid). However, this process has the following inherent defects: (1) Uneven dispersion of reactants: During the mixing and hydrolysis process, the precursor concentration may be too high or too low in some areas. Too high a concentration will cause the gel particles to grow abnormally and form large agglomerates; too low a concentration will easily generate ultrafine particles. This bimodal distribution of particle size will be transmitted to the sintered membrane layer, resulting in an excessively wide membrane pore size distribution and reduced separation selectivity. (2) High sensitivity to process control: Existing methods are extremely sensitive to subtle changes in reaction conditions (e.g., temperature gradient, stirring efficiency), making it difficult to ensure batch-to-batch consistency in large-scale production.

[0004] Therefore, the uncontrollable nature of reactant dispersion in existing sol-gel processes has become a bottleneck restricting the manufacturing of high-performance ceramic membranes. There is an urgent need to develop an improved process that can significantly enhance sol dispersion uniformity and achieve narrow particle size distribution gel synthesis to meet the application requirements of high-precision separation membranes.

[0005] In view of this, it is necessary to improve the existing methods for preparing titanium dioxide sol in order to solve the above problems. Utility Model Content

[0006] The purpose of this invention is to disclose a device for preparing nano-sized titanium dioxide particle sol. This device uses a full membrane process to control the preparation of titanium dioxide particle sol, specifically including: ① dynamic microporous ceramic membrane feeding, dynamic rotation + microporous permeation to achieve high homogenization of the reaction system; ② dynamic ceramic membrane for separating, concentrating and washing intermediate products, and purifying intermediate products; ③ dynamic microporous ceramic reactor for online particle classification of reaction products to achieve uniformity of product particles; ④ pervaporation membrane for efficient separation of alcohol and water, enabling alcohol reuse.

[0007] To achieve the above objectives, this utility model discloses a device for preparing nano-sized titanium dioxide particle sol, comprising a membrane reactor D1, a membrane separator D2, a membrane separator D3, a membrane reactor D4, and a membrane separator D5 connected in sequence; the concentrate side of the membrane reactor D1 is connected to the concentrate side of the membrane separator D2, and the clear liquid side of the membrane separator D2 is connected to the concentrate side of the membrane separator D3; the concentrate side of the membrane separator D2 is connected to the concentrate side of the membrane reactor D4, the clear liquid side of the membrane reactor D4 is connected to the concentrate side of the membrane separator D5, and the clear liquid side of the membrane separator D5 is connected to the concentrate side of the membrane reactor D4; the filter element in the membrane reactor D1 is used as a distributor.

[0008] In some embodiments, the concentrate side of the membrane separator D2 is connected to a pure water source.

[0009] In some embodiments, the clear liquid side of the membrane separator D2 is connected to a reverse osmosis system.

[0010] In some embodiments, the membrane reactor D1 is a dynamic rotating membrane reactor, the filter element of the membrane reactor D1 is a disc membrane, and the filtration accuracy of the membrane is 2~2000nm.

[0011] In some embodiments, the membrane reactor D1 includes a shell, a hollow rotating shaft penetrating the bottom of the shell, a driver connected below the hollow rotating shaft, the upper part of the hollow rotating shaft located inside the shell and equipped with a plurality of filter elements and spacers, the upper part of the shell is also provided with a first liquid inlet and a liquid outlet, and the lower part of the hollow rotating shaft is provided with a second liquid inlet.

[0012] In some embodiments, the membrane reactor D1 further includes a stirring device located above the hollow rotating shaft.

[0013] In some embodiments, the filter element and the spacer are arranged sequentially at intervals, and the filter element is used as a distributor.

[0014] In some embodiments, the membrane separator D3 is a molecular sieve membrane separator, and the filter element of the membrane separator D3 is any one of a disc membrane, a tubular membrane, or a hollow fiber membrane.

[0015] In some embodiments, the filter element material of the membrane separator D3 is one or more of type A, type CHA, or type MFI.

[0016] In some embodiments, the transmembrane pressure difference of the membrane reactor D1 is 0-300 kPa, and the rotational speed of the filter element of the membrane reactor D1 is 0-1000 r / min.

[0017] In some embodiments, the membrane reactor D4 is a dynamic rotating membrane reactor, the filter element of the membrane reactor D4 rotates at a speed of 0-1000 r / min, and the transmembrane pressure difference of the membrane reactor D4 is 0-500 kPa.

[0018] In some embodiments, the membrane separator D2 has a filtration accuracy of 50-1000 nm, the membrane reactor D4 has a filtration accuracy of 2-500 nm, and the membrane separator D5 has a filtration accuracy of 2-200 nm.

[0019] Compared with existing technologies, the advantages of this invention are as follows: This invention employs a full-membrane process, including membrane dispersion, membrane separation, membrane concentration, membrane washing, membrane classification, and membrane recovery, to achieve continuous preparation of nano-sized titanium dioxide particle sol; the use of membrane reactor D1 (dynamic rotating membrane reactor) to add reactants ensures more uniform dispersion of reactants in the system, suppressing excessively wide particle size distribution caused by excessively high or low local concentrations; the use of membrane separator D2 to separate, concentrate, and wash intermediate products, reducing their alcohol content; the use of membrane separator D3 (molecular sieve membrane) to achieve efficient separation of alcohol and water, with an alcohol recovery rate exceeding 95%; the use of membrane reactor D4 to prepare the target product, combined with membrane separator D5 for online particle classification of the target product; and the hydrolysis and polymerization of reactants in the entire reaction system under low concentration conditions, which is beneficial for controlling the uniformity of product particle size distribution. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the preparation structure of nanoscale titanium dioxide particle sol as shown in this utility model;

[0021] Figure 2 This is a schematic diagram of the structure of the membrane reactor D1 shown in this utility model;

[0022] Figure 3 A schematic diagram of the process for preparing nanoscale titanium dioxide particle sol using the apparatus shown in this utility model;

[0023] Figure 4 This is a schematic diagram of the D4 stage effect of the membrane reactor shown in this utility model. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, it should be noted that these embodiments are not intended to limit the present invention. Any equivalent substitutions or replacements made by those skilled in the art based on these embodiments in terms of function, method, or structure shall fall within the protection scope of the present invention.

[0025] Example 1

[0026] like Figure 1-2 As shown, an apparatus for preparing nano-sized titanium dioxide particle sol includes a membrane reactor D1, a membrane separator D2, a membrane separator D3, a membrane reactor D4, and a membrane separator D5 connected in sequence. The concentrate side of the membrane reactor D1 is connected to the concentrate side of the membrane separator D2, and the clear liquid side of the membrane separator D2 is connected to the concentrate side of the membrane separator D3. The concentrate side of the membrane separator D2 is connected to the concentrate side of the membrane reactor D4, the clear liquid side of the membrane reactor D4 is connected to the concentrate side of the membrane separator D5, and the clear liquid side of the membrane separator D5 is connected to the concentrate side of the membrane reactor D4.

[0027] The concentrate side of membrane separator D2 is connected to a pure water source, which can be used to wash intermediate product C in membrane separator D2 to reduce the alcohol content of intermediate product C. The clarified liquid side of membrane separator D2 is connected to a reverse osmosis system. The washing wastewater of membrane separator D2 enters the reverse osmosis system for concentration. The concentrated liquid then enters membrane separator D3 for further separation, achieving efficient separation of alcohol solvent A and water, and reusing alcohol solvent A with a recovery rate of over 95%.

[0028] The membrane reactor D1 is a dynamic rotating membrane reactor, and the filter element of the membrane reactor D1 is a disc membrane with a filtration accuracy of 2~2000nm. The filter element is made of one or a combination of alumina, zirconium oxide, titanium oxide, silicon oxide, yttrium oxide, cerium oxide, lanthanum oxide, and silicon carbide.

[0029] The membrane reactor D1 includes a shell 1, a hollow rotating shaft 2 that runs through the bottom of the shell, a driver 3 connected below the hollow rotating shaft 2, the upper part of the hollow rotating shaft 2 located inside the shell 1 and equipped with several filter elements 5 and spacers 6, the upper part of the shell 1 is also provided with a first liquid inlet 10 and a liquid outlet 11, and the lower part of the hollow rotating shaft 2 is provided with a second liquid inlet 4.

[0030] The membrane reactor D1 also includes a stirring device 9 located above the hollow rotating shaft 2. The rotating shaft 8 above the membrane reactor D1 is controlled by a motor 7, and the stirring device 9 is connected below the rotating shaft 8. When the membrane reactor D1 is working, the stirring device 9 accelerates the stirring and dispersion, which can further enhance the uniformity of the dispersion of the reactants.

[0031] In this embodiment, the membrane reactor D1 is provided with multiple filter elements 5 and spacers 6, which are arranged sequentially at intervals. Two adjacent spacers 6 can securely seal the filter element 5 to the central control shaft 2. Compared to the prior art, in this invention, the filter element 5 is used as a distributor and is no longer used for material separation.

[0032] The membrane separator D3 is a molecular sieve membrane separator, and the filter element of the membrane separator D3 is any one of disc membrane, tubular membrane or hollow fiber membrane.

[0033] The filter element material of the membrane separator D3 is one or more of type A, type CHA, or type MFI.

[0034] The membrane separator D2 has a filtration accuracy of 50-1000 nm. The membrane reactor D4 has a filtration accuracy of 2-500 nm. The membrane separator D5 has a filtration accuracy of 2-200 nm.

[0035] In this invention, both membrane separator D2 and membrane reactor D4 employ dynamic rotating membranes. Membrane separator D5 can employ a dynamic rotating membrane, a tubular membrane, a hollow fiber membrane, or a spiral wound membrane. Unlike membrane reactor D1, the filter elements in membrane separators D2, D4, and D5 are used for filtration, separation, and concentration, not as distributors. The material of their filter elements can be the same as that of membrane reactor D1.

[0036] The clear liquid side of this invention refers to the side that passes through the filter element, while the concentrated liquid side refers to the side that does not pass through the filter element, i.e., the outer side of the filter element.

[0037] Example 2

[0038] like Figure 1-4 As shown, this utility model provides a method for preparing nano-sized titanium dioxide particle sol, comprising the following steps:

[0039] S1: Mix alcohol solvent A and titanium precursor B uniformly, and control the concentration of titanium precursor B to obtain reactant AB;

[0040] S2: Mix alcohol solvent A and deionized water evenly, and control the concentration of deionized water to obtain reactant AH;

[0041] S3: Reactants AB and AH are added to membrane reactor D1 for reaction, and the feed concentration of reactant AH is controlled to obtain intermediate product C;

[0042] S4: Pass intermediate product C into membrane separator D2 to separate and concentrate the solid intermediate product C and the liquid material. Then, pass the liquid material into membrane separator D3 for post-treatment to obtain alcohol solvent A for reuse. The separated water is discharged into the wastewater treatment system.

[0043] S5: Add deionized water to membrane separator D2 multiple times to wash solid intermediate product C multiple times. After washing, intermediate product C is passed into membrane reactor D4.

[0044] S6: Add pectin D to membrane reactor D4 to carry out the reaction, control the concentration of pectin D, and obtain a low concentration of target product E. The membrane reactor D4 is a dynamic rotating membrane reactor. The rotation speed of the filter element of the membrane reactor D4 is 0-1000 r / min, and the transmembrane pressure difference of the membrane reactor D4 is 0-500 kPa.

[0045] S7: Membrane separator D5 concentrates the target product to obtain a high concentration of nano-sized titanium dioxide particle sol.

[0046] The alcohol solvent A is one or more of ethanol, n-propanol, isopropanol, and n-butanol, and the titanium precursor B is one or more of tetraethyl titanate, n-propyl titanate, tetraisopropyl titanate, and n-butyl titanate.

[0047] The concentration of the titanium precursor B, C(Ti), is 0.001-0.5 mol / L, and the concentration of the deionized water, C(H2O), is 0.001-55.5 mol / L.

[0048] The adhesive solvent D is one or more of nitric acid, sulfuric acid, hydrochloric acid, oxalic acid, acetic acid, and perchloric acid.

[0049] The reactant AH enters the membrane reactor D1 through the second inlet 4, and the reactant AB enters the membrane reactor D1 through the first inlet 10. The reactant AH is distributed through the micropores of the membrane layer of the filter element 5, which can be uniformly dispersed in the membrane reactor D1 to avoid excessive local concentration. The reactants AH and AB come into contact on the outer surface of the filter element 5 and undergo a hydrolysis reaction.

[0050] The molar ratio of reactant AH to reactant AB in S1 is n(Ti):n(H2O) = 0.01~1. The reaction temperature of the membrane reactor D1 is 5~80℃, the reaction time is 5~120min, the transmembrane pressure difference of the membrane reactor D1 is 0-300kPa, and the rotation speed of the filter element of the membrane reactor D1 is 0~1000r / min.

[0051] Membrane reactor D1 utilizes the microporous membrane layer of the filter element. By controlling the membrane pore size and feed conditions, the reactant AH is uniformly dispersed in membrane reactor D1, avoiding excessively high local concentrations.

[0052] In step S6, intermediate product C enters membrane reactor D4, where colloid D and intermediate product C are added to react. The molar ratio of the two is n(H+):n(Ti) = 0.01~10. The reaction temperature of membrane reactor D4 is 5~100℃, and the reaction time is 0.5~24h, to obtain target product E. The particle size of target product E is smaller than the pore size of the filter element in membrane reactor D4. It passes through the filter element and enters membrane separator D5 for further concentration to obtain nano-sized titanium dioxide particle sol product.

[0053] This invention employs a full-membrane process, encompassing membrane dispersion, membrane separation, membrane concentration, membrane washing, membrane classification, and membrane recovery, to achieve continuous preparation of nano-sized titanium dioxide particle sol. A membrane reactor D1 (dynamic rotating membrane reactor) is used to add reactants, ensuring more uniform dispersion within the system and suppressing excessively wide particle size distribution caused by localized high or low concentrations. A membrane separator D2 separates, concentrates, and washes intermediate products, reducing their alcohol content. A membrane separator D3 (molecular sieve membrane) achieves efficient separation of alcohol and water, with an alcohol recovery rate exceeding 95%. The target product is prepared using a membrane reactor D4, and then further classified online using a membrane separator D5. The hydrolysis and polymerization of reactants in the entire reaction system under low concentration conditions facilitates control over the uniformity of product particle size distribution.

[0054] Membrane separator D4 passes the target product through membrane separator D5 for further concentration, while retaining large particle sols, as shown in Table 1. Figure 4 It can be seen that particles smaller than 100 nm are allowed to enter membrane separator D5 for further concentration, ultimately yielding nano-sized titanium dioxide particle sol. Table 2 shows that the permeate from membrane separator D5 does not meet the minimum photon count required for the test, indicating that the nano-sized sol particles are intercepted on the outside of the filter element. This further demonstrates that the method can achieve the preparation of nano-sized titanium dioxide particle sol.

[0055] In this embodiment, the membrane separator D5 can be made of different filter elements and tested.

[0056] Table 1. Permeate particle size test for membrane separators D4 and D5

[0057]

[0058] Table 2. Classification and screening of sols with different particle sizes by membrane separator D4

[0059]

[0060] The detailed descriptions listed above are merely specific descriptions of feasible implementations of this utility model, and are not intended to limit the scope of protection of this utility model. All equivalent implementations or modifications made without departing from the spirit of this utility model should be included within the scope of protection of this utility model.

[0061] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An apparatus for preparing nanoscale titanium dioxide particle sol, characterized in that, The system comprises membrane reactor D1, membrane separator D2, membrane separator D3, membrane reactor D4, and membrane separator D5 connected in sequence. The concentrate side of membrane reactor D1 is connected to the concentrate side of membrane separator D2, and the clear liquid side of membrane separator D2 is connected to the concentrate side of membrane separator D3. The concentrate side of membrane separator D2 is connected to the concentrate side of membrane reactor D4, the clear liquid side of membrane reactor D4 is connected to the concentrate side of membrane separator D5, and the clear liquid side of membrane separator D5 is connected to the concentrate side of membrane reactor D4. The filter element in membrane reactor D1 is used as a distributor.

2. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 1, characterized in that, The concentrate side of the membrane separator D2 is connected to a pure water source.

3. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 2, characterized in that, The clear liquid side of the membrane separator D2 is connected to a reverse osmosis system.

4. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 1, characterized in that, The membrane reactor D1 is a dynamic rotating membrane reactor, and the filter element of the membrane reactor D1 is a disc membrane with a filtration accuracy of 2~2000nm.

5. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 4, characterized in that, The membrane reactor D1 includes a shell (1), a hollow rotating shaft (2) that runs through the bottom of the shell, a driver (3) connected below the hollow rotating shaft (2), the upper part of the hollow rotating shaft (2) is located inside the shell (1) and is equipped with several filter elements (5) and spacers (6), the upper part of the shell (1) is also provided with a first liquid inlet (10) and a liquid outlet (11), and the lower part of the hollow rotating shaft (2) is provided with a second liquid inlet (4).

6. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 5, characterized in that, The membrane reactor D1 also includes a stirring device (9) located above the hollow rotating shaft (2).

7. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 5, characterized in that, The filter element (5) and the spacer (6) are arranged in sequence at intervals, and the filter element (5) is used as a distributor.

8. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 1, characterized in that, The membrane separator D3 is a molecular sieve membrane separator, and the filter element of the membrane separator D3 is any one of disc membrane, tubular membrane or hollow fiber membrane.

9. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 8, characterized in that, The filter element material of the membrane separator D3 is one or more of type A, type CHA, or type MFI.

10. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 4, characterized in that, The transmembrane pressure difference of the membrane reactor D1 is 0-300 kPa, and the rotation speed of the filter element of the membrane reactor D1 is 0-1000 r / min.

11. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 1, characterized in that, The membrane reactor D4 is a dynamic rotating membrane reactor, the filter element of the membrane reactor D4 rotates at a speed of 0-1000 r / min, and the transmembrane pressure difference of the membrane reactor D4 is 0-500 kPa.

12. The apparatus for preparing nanoscale titanium dioxide particle sol according to claim 4, characterized in that, The membrane separator D2 has a filtration accuracy of 50-1000nm, the membrane reactor D4 has a filtration accuracy of 2-500nm, and the membrane separator D5 has a filtration accuracy of 2-200nm.

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