A water removing agent, its preparation method and application

Abstract

The application discloses a kind of water removing agent and its preparation method and application.The water removing agent of the present application is a composite water removing agent composed of inorganic matrix calcium oxide, silicon oxide and activated carbon;Among them, the content of calcium oxide is 21-53wt%, the content of silicon oxide is 18-50wt%, and the content of activated carbon is 29-61wt%.The water removing agent of the present application can remove trace water in cumene hydroperoxide.The water removing agent has the advantages of good water removal effect, low cost and stable performance.

Description

Technical Field

[0001] This invention belongs to the field of post-treatment technology of phenyl peroxide, specifically relating to a dehydrating agent, its preparation method and application. Background Technology

[0002] The process of producing propylene oxide from cumene by hydrogen peroxide (CHPPO) involves: air oxidation of cumene to generate a certain concentration of cumene hydrogen peroxide (CHP); CHP and propylene undergo an epoxidation reaction to produce propylene oxide and α,α-dimethylbenzyl alcohol; α,α-dimethylbenzyl alcohol then undergoes hydrogenolysis to produce cumene. The CHPPO process generates certain amounts of impurities such as organic acids, alcohols, and phenols, which can reduce the selectivity of α,α-dimethylbenzyl alcohol and propylene oxide during the CHP oxidation of propylene.

[0003] To reduce the impact of impurities on the reaction, CHP is typically subjected to alkaline and water washing. After oil-water separation and concentration, the washed CHP still contains 0.1-1.0 wt% water. During the epoxidation reaction of CHP and propylene, the water in CHP reacts with propylene oxide to form propylene glycol and propylene glycol polymers, leading to a decrease in propylene oxide yield. Simultaneously, the propylene glycol polymers clog the pores of the epoxidation catalyst, causing catalyst deactivation and reduced lifetime. Therefore, reducing the trace amount of water in CHP is crucial for minimizing side reactions during the epoxidation process and extending catalyst lifetime.

[0004] Currently, there are few reports on reducing the moisture content of cumene hydrogen peroxide in the CHPPO process. Traditional dehydrating agents, such as calcium oxide and aluminum oxide, have poor dehydration effects on cumene hydrogen peroxide. Calcium chloride and anhydrous copper sulfate not only have poor dehydration effects on cumene hydrogen peroxide, but also cause the material to decompose, producing impurities such as α-methylstyrene and phenol.

[0005] CN111807920A discloses a method and system for deacidifying cumene feedstock in a CHPPO unit. This invention uses a mixer-cyclone separator-aggregator mixing system to remove organic acids, but the disclosed mixing system does not involve a technical solution for removing moisture from CHP.

[0006] CN113861133A discloses a method for removing organic acids from the products of cumene oxidation reaction. The method involves separating most of the water by allowing the solution to stand, and then separating trace amounts of water from the cumene oxidation liquid using a high-efficiency coalescer. This invention only discloses data on the amount of organic acids removed. Summary of the Invention

[0007] Objective of this invention: To address the shortcomings of existing technologies, this invention provides a dehydrating agent, its preparation method, and its application. The dehydrating agent provided by this invention can remove trace amounts of water from cumene hydrogen peroxide. This dehydrating agent has the advantages of good dehydration effect and stable performance.

[0008] Technical solution: The objective of this invention is achieved through the following technical solution:

[0009] This invention provides a dehydrating agent, which is a composite dehydrating agent composed of inorganic matrix calcium oxide, silicon dioxide and activated carbon; wherein the calcium oxide content is 21-53 wt%, the silicon dioxide content is 18-50 wt%, and the activated carbon content is 29-61 wt%.

[0010] In a preferred embodiment of the present invention, calcium oxide, silicon oxide, and activated carbon are composited using a silane coupling agent.

[0011] In this process, the silane coupling agent acts as a bridge and modifier. By combining three inorganic matrices using the silane coupling agent, the new composite dehydrator exhibits advantages such as good dehydration effect and stable performance.

[0012] Preferably, the calcium oxide content is 21-46 wt%, the silicon oxide content is 18-48 wt%, and the activated carbon content is 30-40 wt%.

[0013] Preferably, the specific surface area of ​​the dehydrating agent is 200-600 m². 2 / g. The larger the specific surface area, the better the water removal effect.

[0014] The present invention also provides a method for preparing the above-mentioned dehydrating agent, comprising the following steps:

[0015] (1) Treat with activated carbonic acid;

[0016] (2) Add the activated carbon, calcium oxide and silane coupling agent after acid treatment in step (1) to the nano silica sol solution and disperse them to obtain a mixed solution;

[0017] (3) Heat and dry the mixture obtained in step (2) to obtain a dried body;

[0018] (4) The dried body obtained in step (3) is calcined at high temperature to obtain the dehydrating agent.

[0019] The purpose of acid treatment in step (1) of this invention is to increase the pore volume of activated carbon and the number of attached surface active groups. During acid treatment, activated carbon and acidic aqueous solution can be mixed, stirred, and refluxed. After reflux, the activated carbon is filtered and washed with deionized water. After drying, the treated activated carbon can be obtained.

[0020] Preferably, in step (1), the activated carbon has a particle size of 0.5–5 mm and a specific surface area of ​​1000–1400 m². 2 / g; the acid used for acid treatment is selected from one or more of nitric acid, sulfuric acid, hydrochloric acid or phosphoric acid.

[0021] The selected acid is prepared into an acidic aqueous solution, and its concentration should not be too high to avoid damaging the surface structure of the activated carbon. The preferred concentration of the acidic aqueous solution is 1-35 wt%. The activated carbon can be selected from one or more of the following shapes: block, sheet, etc., and the material can be one or more of the following: wood-based activated carbon, coconut shell activated carbon, fruit shell activated carbon, coal-based activated carbon.

[0022] To balance cost and acid treatment effectiveness, a further optimized mass ratio of activated carbon to acidic aqueous solution is 1:3-1:9. When mixing and stirring the activated carbon and acidic aqueous solution, the stirring speed should not be too fast, preferably 100-300 r / min. The reflux temperature is 85-100℃. The time for stirring and reflux after mixing the activated carbon and acidic aqueous solution is 4-8 hours, preferably drying the activated carbon to constant weight at 90-150℃. The activated carbon is then washed with deionized water until the pH of the wash water is 5.0-7.0, which is weakly acidic, ensuring that sufficient acidic active groups remain on the surface of the activated carbon.

[0023] Preferably, in step (2), the particle size of the calcium oxide is 10-150 mesh; the particle size of the nano silica sol is 3-100 nm; the pH value of the nano silica sol solution is 2.0-11.0; and the mass ratio of the acid-treated activated carbon, calcium oxide, nano silica sol and silane coupling agent is (5-10):(5-10):(10-30):(1-5).

[0024] The particle size of the calcium oxide should not be too large in order to enhance its adhesion to activated carbon. Commonly available nano-sized silica sol models such as JN20, JN25, JN30, JN40, SW20, SW25, and SW30 are selected.

[0025] Preferably, in step (2), the dispersion is carried out by means of stirring, ultrasonic treatment, etc., so that the components are dispersed evenly.

[0026] Preferably, in step (2), the silane coupling agent is selected from one or more of hexadecyltrimethoxysilane, vinyltriethoxysilane, 3-glycidyloxypropyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, and aminopropyltriethoxysilane. Preferably, this is to achieve hydrophobic or hydrophilic properties in the composite dehydrating agent.

[0027] In step (3) of this invention, water is evaporated through drying, and the active groups are initially combined. In the mixed solution, the organosilicon groups of the silane coupling agent undergo hydrolysis to generate active groups such as silicon oxide; calcium oxide reacts with water to generate calcium hydroxide, which contains active groups such as hydroxyl groups; activated carbon, after treatment with an acidic solution, contains groups such as hydroxyl and carboxyl groups; and the silica inside the silica sol solution contains a large number of groups such as hydroxyl groups. Through heating, water evaporates on one hand, and the various groups undergo condensation reactions to combine together on the other.

[0028] Preferably, in step (3), the heating and drying temperature is 120-200℃ and the time is 2-10h.

[0029] Preferably, in step (4), the high-temperature calcination temperature is 500-650℃, and the time is 3-10h. High-temperature calcination serves two purposes: first, to achieve a further and more comprehensive chemical reaction between the active groups such as hydroxyl and carboxyl groups on the surfaces of calcium oxide, silicon oxide, activated carbon, and the silane coupling agent, generating stable chemical bonds; second, to dehydrate calcium hydroxide into calcium oxide, giving it water-absorbing properties; and third, to more thoroughly remove moisture from silicon oxide and activated carbon. The high-temperature calcined calcium oxide-silicon oxide-activated carbon composite dehydrating agent is placed in a drying device for cooling and storage to prevent water absorption and deterioration.

[0030] The present invention also provides the application of the aforementioned dehydrating agent in removing moisture from cumene hydrogen peroxide solution.

[0031] The mass fraction of cumene hydrogen peroxide in the cumene hydrogen peroxide solution is 8-80%.

[0032] The water content in the cumene hydrogen peroxide solution is 0.1–1.0 wt%.

[0033] As a further improvement to the technical solution, the mass fraction of cumene hydrogen peroxide in the cumene hydrogen peroxide solution is 8-80%, which meets the concentration requirements of cumene hydrogen peroxide for industrial production.

[0034] Beneficial effects:

[0035] The dehydrating agent provided by this invention has stable chemical properties. It is recyclable and regenerable, maintaining high dehydration efficiency even after multiple reuses, thus reducing economic costs. When applied to cumene hydrogen peroxide solutions, the dehydrating agent reduces the moisture content from 0.1-1.0 wt% to below 0.05 wt%, demonstrating excellent dehydration performance. Therefore, the dehydrating agent of this invention offers advantages such as stable performance, low cost, and excellent dehydration effect. Detailed Implementation

[0036] The technical solution of the present invention will be described in detail below through specific embodiments, but the scope of protection of the present invention is not limited to the embodiments described.

[0037] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0038] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the experimental materials used in the following examples are commercially available products.

[0039] In the examples of preparing the dehydrating agent, X-ray fluorescence spectrometry was used to determine the elemental content of calcium and silicon in the dehydrating agent, and then the contents of calcium oxide, silicon oxide and activated carbon were calculated. The specific surface area of ​​the composite dehydrating agent was detected by a fully automatic specific surface area analyzer.

[0040] Example 1

[0041] (1) Select particles with a size of 0.6-1mm and a specific surface area of ​​1050-1160m². 2 / g of blocky coconut shell activated carbon. The activated carbon and 7wt% nitric acid aqueous solution were mixed at a mass ratio of 1:4. The mixture was stirred and refluxed for 5 hours at a stirring speed of 300 r / min and a reflux temperature of 95℃. After filtration, the mixture was washed with deionized water until the pH of the wash water reached 5.5. The treated activated carbon was then dried in an oven at 95℃ to constant weight.

[0042] (2) Select a nano-silica sol solution of type JN25 with a particle size of 90-99 nm and a solution pH of 11.0. Use 10-20 mesh calcium oxide powder. Mix calcium oxide, silica sol, activated carbon and hexadecyltrimethoxysilane in a mass ratio of 5:15:5:1, stir at 35℃ and 100 r / min for 4 hours to obtain a mixed solution.

[0043] (3) The mixture was dried at 180℃ for 3 hours, and then the dried mixture was calcined in a muffle furnace at 580℃ for 5 hours to obtain a calcium oxide-silica-activated carbon composite dehydrating agent, wherein the calcium oxide content was 36.4%, the silica content was 27.3%, and the activated carbon content was 36.3%, and its specific surface area was 381 m². 2 / g.

[0044] Example 2

[0045] (1) Select particles with a size of 4.4-4.9 mm and a specific surface area of ​​1120-1300 m².2 / g of blocky wood-based activated carbon was mixed with 15wt% sulfuric acid aqueous solution at a mass ratio of 1:9. The activated carbon was added to the sulfuric acid aqueous solution, stirred and refluxed for 6 hours at a stirring speed of 100r / min and a reflux temperature of 90℃. After filtration, it was washed with deionized water until the pH of the wash water was 5.5. It was then dried in an oven at 145℃ to constant weight to obtain the treated activated carbon.

[0046] (2) Select a nano silica sol solution of type JN40 with a particle size of 5-15 nm and a pH value of 8.0. Use 60-70 mesh calcium oxide powder. Mix calcium oxide, silica sol, activated carbon and methyltriethoxysilane in a mass ratio of 5:25:7:4, stir at 70℃ and 100 r / min for 4 hours to obtain a mixed solution.

[0047] (3) The mixture was dried at 125℃ for 8 hours, and then the dried mixture was calcined in a muffle furnace at 645℃ for 5 hours to obtain a calcium oxide-silica-activated carbon composite dehydrating agent, wherein the calcium oxide content was 22.7%, the silica content was 45.4%, the activated carbon content was 31.9%, and its specific surface area was 431 m². 2 / g.

[0048] Example 3

[0049] (1) Select particles with a size of 1-2.4 mm and a specific surface area of ​​1200-1380 m². 2 / g of flake coal-based activated carbon was mixed with 30wt% hydrochloric acid aqueous solution at a mass ratio of 1:7. The activated carbon was added to the hydrochloric acid aqueous solution, stirred and refluxed for 7 hours at a stirring speed of 150r / min and a reflux temperature of 95℃. After filtration, it was washed with deionized water until the pH of the wash water was 6.5. It was then dried in an oven at 110℃ to constant weight to obtain the treated activated carbon.

[0050] (2) Select SW30 nano silica sol solution with a particle size of 40-50 nm and a pH of 4.0. Use 135-145 mesh calcium oxide powder. Mix calcium oxide, silica sol, activated carbon and aminopropyltriethoxysilane in a mass ratio of 8:12:6:2, stir at 55℃ and 100 r / min for 6 hours to obtain a mixed solution.

[0051] (3) The mixture was dried at 150℃ for 9 hours, and then the dried mixture was calcined in a muffle furnace at 530℃ for 8 hours to obtain a calcium oxide-silica-activated carbon composite dehydrating agent, wherein the calcium oxide content was 45.4%, the silica content was 20.5%, the activated carbon content was 34.1%, and its specific surface area was 510 m².2 / g.

[0052] Example 4

[0053] (1) Select particles with a particle size of 2.5-4.2 mm and a specific surface area of ​​1300-1420 m². 2 / g of flake-shaped fruit shell activated carbon was mixed with 23wt% phosphoric acid aqueous solution at a mass ratio of 1:6. The activated carbon was added to the phosphoric acid aqueous solution, stirred and refluxed for 6 hours at a stirring speed of 250r / min and a reflux temperature of 99℃. After filtration, it was washed with deionized water until the pH of the wash water was 6.0. It was then dried in an oven at 120℃ to constant weight to obtain the treated activated carbon.

[0054] (2) Select a nano-silica sol solution of type JN40 with a particle size of 65-75 nm and a solution pH of 9.0. Use 100-110 mesh calcium oxide powder. Mix calcium oxide, silica sol, activated carbon and 3-glycidyl etheroxypropyltrimethoxysilane in a mass ratio of 6:15:6:1. Stir at 40℃ and 100 r / min for 4 hours to obtain a mixed solution.

[0055] (3) The mixture was dried at 120℃ for 9 hours, and then the dried mixture was calcined in a muffle furnace at 630℃ for 9 hours to obtain a calcium oxide-silica-activated carbon composite dehydrating agent, wherein the calcium oxide content was 33.3%, the silica content was 33.3%, the activated carbon content was 33.4%, and its specific surface area was 585 m². 2 / g.

[0056] Example 5

[0057] The dehydrating agent prepared in Example 1 was installed in a tubular adsorption bed, and a 200 cm³ packing bed was formed in the tubular adsorption bed. 3 The dehydrating agent was used to dehydrate the cumene hydrogen peroxide solution, which was pumped from the top into the tubular adsorption bed via a peristaltic pump. Under normal pressure, the liquid was dehydrated by passing through the dehydrating agent from top to bottom. The concentration of the cumene hydrogen peroxide solution was 17 wt%, and the flow rate of the peristaltic pump was 100 ml / min. The dehydration results are shown in Table 1.

[0058] Example 6

[0059] The operation steps in this embodiment are the same as those in Example 5, except that the dehydrating agent used is the one prepared in Example 2, and the concentration of cumene hydrogen peroxide solution is 80 wt%. The dehydration results are shown in Table 1.

[0060] Example 7

[0061] The operation steps in this embodiment are the same as those in Example 5, except that the dehydrating agent used is the one prepared in Example 3, and the concentration of cumene hydrogen peroxide solution is 37 wt%. The dehydration results are shown in Table 1.

[0062] Example 8

[0063] The operation steps in this embodiment are the same as those in Example 5, except that the dehydrating agent used is the one prepared in Example 4, and the concentration of cumene hydrogen peroxide solution is 57 wt%. The dehydration results are shown in Table 1.

[0064] Example 9

[0065] The water-absorbing composite dehydrating agent from Example 5 was selected and placed in a muffle furnace for high-temperature calcination at 600°C. The first-recovery composite dehydrating agent was obtained by heating and regeneration. The composite dehydrating agent was then subjected to dehydration operation according to the steps of Example 5.

[0066] The above regeneration and dewatering steps were repeated to perform the second, third, fourth, fifth, and sixth regeneration-dewatering operations on the composite dewatering agent. The results are shown in Table 2.

[0067] Table 1. Water removal results of Examples 5-8

[0068]

[0069] As can be seen from the data in Table 1, the present invention has a good dehydration effect on the feed solution with a concentration range of cumene hydrogen peroxide in industrial production. It can reduce the water content of cumene hydrogen peroxide with a water content of 0.3-1.0 wt% to below 0.05 wt%, and the dehydration effect is even better for feed solutions with lower water content.

[0070] Table 2 shows the water removal effect of Example 9.

[0071]

[0072] As can be seen from the data in Table 2, after 6 recycling cycles, the composite dehydrating agent can still reduce the moisture content of CHP materials with a moisture content of 0.3-1.0 wt% to below 0.05 wt%, demonstrating good stability.

[0073] Comparative Example

[0074] The comparative example follows the same operating steps as Example 5, using calcium oxide, aluminum oxide, calcium chloride, and anhydrous copper sulfate as dehydrating agents, respectively, with a cumene hydrogen peroxide solution concentration of 55 wt%. The dehydration results are shown in Table 3.

[0075] Table 3 Comparative water removal results

[0076]

[0077] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. The application of a dehydrating agent in removing moisture from cumene hydrogen peroxide solution, characterized in that, The dehydrating agent is a composite dehydrating agent composed of inorganic matrix calcium oxide, silicon dioxide and activated carbon; wherein the calcium oxide content is 21-46 wt%, the silicon dioxide content is 18-48 wt%, and the activated carbon content is 30-40 wt%. Three inorganic matrices, calcium oxide, silicon oxide, and activated carbon, are combined using a silane coupling agent. The preparation method of the dehydrating agent includes the following steps: (1) treating activated carbon with acid; (2) adding activated carbon, calcium oxide and silane coupling agent after acid treatment in step (1) into nano silica sol solution and dispersing them to obtain a mixed liquid; (3) heating and drying the mixed liquid obtained in step (2) to obtain a dried body; (4) calcining the dried body obtained in step (3) at high temperature to obtain the dehydrating agent.

2. The application according to claim 1, characterized in that, The silane coupling agent is selected from one or more of the following: hexadecyltrimethoxysilane, vinyltriethoxysilane, 3-glycidyl ether propyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, tetraethoxysilane, phenyltrimethoxysilane, and aminopropyltriethoxysilane.

3. The application according to claim 1, characterized in that, The specific surface area of ​​the dehydrating agent is 200-600 m². 2 / g.

4. The application according to claim 1, characterized in that, In step (1), the activated carbon has a particle size of 0.5–5 mm and a specific surface area of ​​1000–1400 m². 2 / g; the acid used for acid treatment is selected from one or more of nitric acid, sulfuric acid, hydrochloric acid or phosphoric acid.

5. The application according to claim 1, characterized in that, In step (2), the particle size of the calcium oxide is 10-150 mesh; the particle size of the nano silica sol is 3-100 nm; the pH value of the nano silica sol solution is 2.0-11.0; and the mass ratio of the acid-treated activated carbon, calcium oxide, nano silica sol and silane coupling agent is (5-10):(5-10):(10-30):(1-5).

6. The application according to claim 1, characterized in that, In step (3), the heating and drying temperature is 120-200℃ and the time is 2-10h; in step (4), the high-temperature roasting temperature is 500-650℃ and the time is 3-10h.

7. The application according to claim 1, characterized in that, The mass fraction of cumene hydrogen peroxide in the cumene hydrogen peroxide solution is 8-80%; the water content in the cumene hydrogen peroxide solution is 0.1-1.0 wt%.

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