A kind of preparation method of isopropylhydroxylamine

Abstract

The invention relates to the technical field of isopropylhydroxylamine, and discloses a method for preparing isopropylhydroxylamine, comprising the steps of: S1, oxidation treatment; S2, filtering treatment: filtering the material after the oxidation treatment through a filter; S3, acetone oxime treatment; S4, isopropylhydroxylamine treatment: cooling the isopropylamine aqueous solution in S2, and then performing crystallization treatment using a cooling type crystallizer; the isopropylhydroxylamine in the invention is catalytically treated by a modified catalyst, wherein an activator and a volume expander are added to a conventional TS-1 molecular sieve; the activator can prevent reactants from being blocked in the pores of the TS-1 molecular sieve, thereby causing a problem of reduced activity; the volume expander can increase the dielectric capacity, pore volume and specific surface area of ​​the TS-1 molecular sieve, reduce the resistance of the reactants in the catalyst, facilitate diffusion, and enable the isopropylhydroxylamine to react completely in the production process, thereby improving the isopropylamine conversion rate and the isopropylhydroxylamine selectivity of the produced isopropylhydroxylamine.

Description

Technical Field

[0001] The invention relates to the technical field of isopropylhydroxylamine, in particular to a method for preparing isopropylhydroxylamine. Background Art

[0002] N-isopropylhydroxylamine, also known as isopropylhydroxylamine, isopropylhydroxylamine, IPHA, N-hydroxy-2-propylamine, belongs to the class of secondary alkylhydroxylamine substances. Due to its performance as a polymerization inhibitor and terminal polymerization inhibitor, it is mainly used as a polymerization inhibitor and terminal polymerization inhibitor in the production of styrene-butadiene rubber and nitrile-butadiene rubber. It is also used as a deoxidizer for dissolving and removing oxygen in the water supply system of thermal power generation. The existing preparation method of isopropylhydroxylamine uses carbon dioxide or Schiff alkali metal compounds as catalysts and hydrogen peroxide as an oxidant. The catalyst carbon dioxide has the problems of difficult metering and harsh synthesis conditions.

[0003] A Chinese patent discloses a method for preparing N-isopropylhydroxylamine (authorization announcement number CN105152962B). The patented technology uses highly directional titanium silicon molecular sieve TS-1 or TS-2 as a catalyst. The process is simple and easy to operate. The catalyst TS-1 or TS-2 can be directly filtered with a filter, which is easy to separate. The equipment technology requirements are low, and it is easy to achieve industrial production; however, there are some problems: TS-1 has serious carbon deposition when participating in the reaction, and the resistance between the reactant and itself is large, which is easy to accumulate in its pores and cause blockage, thereby reducing its own contact surface area and its own catalytic performance, making the production reaction of isopropylhydroxylamine incomplete, thereby affecting the production quality of isopropylhydroxylamine. Therefore, those skilled in the art provide a method for preparing isopropylhydroxylamine to solve the problems raised in the above background technology. Summary of the invention

[0004] The object of the present invention is to provide a method for preparing isopropylhydroxylamine to solve the problems raised in the above background technology.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for preparing isopropylhydroxylamine comprises the following steps:

[0007] S1, oxidation treatment: isopropylamine, deionized water and modified catalyst are placed in a reactor for heating processing, stirred while heating, hydrogen peroxide is added dropwise within a certain period of time, and then continued to stir for oxidation treatment;

[0008] S2, filtering treatment: filtering the material after the above oxidation treatment through a filter to filter out the modified catalyst, placing the filtrate in a distillation tower for distillation treatment, collecting the isopropylamine aqueous solution in the first temperature section under normal pressure, and collecting the acetone oxime aqueous solution in the second temperature section under vacuum conditions;

[0009] S3, acetone oxime treatment: concentrating the acetone oxime aqueous solution in S2, and then performing crystallization treatment with a cooling crystallizer to obtain co-produced acetone oxime;

[0010] S4, isopropylhydroxylamine treatment: the isopropylamine aqueous solution in S2 is cooled, and then crystallized using a cooling crystallizer to obtain isopropylhydroxylamine crystals.

[0011] As a further solution of the present invention: the processing temperature of the reactor in S1 is 92-98° C., the dripping time of hydrogen peroxide is 20 min, and the total stirring time is 70 min.

[0012] As a further solution of the present invention: the concentration of hydrogen peroxide in S1 is 55%, and the mass ratio of isopropylamine to hydrogen peroxide is 2:1.

[0013] As a further solution of the present invention: the first temperature section in S2 is 30-55°C, the second temperature section is 60-85°C, and the pressure under the vacuum condition is 0.05Mpa.

[0014] As a further solution of the present invention: the modified catalyst in S1 is composed of an activator, an expander and a TS-1 molecular sieve, wherein the weight proportions of the activator, the expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the expander and 10 parts of the TS-1 molecular sieve.

[0015] As a further solution of the present invention: the activator consists of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander consists of triethanolamine.

[0016] As a further solution of the present invention: the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 2-4:22:1-3.

[0017] As a further embodiment of the present invention: the preparation method of the modified catalyst comprises the following steps:

[0018] S101, 0.24 parts of molybdenum trioxide, 2.64 parts of tungsten trioxide, 0.12 parts of calcium oxide, and 10 parts of TS-1 molecular sieve are put into a reactor to react while stirring, and the reaction temperature is 60° C., and then the reactants are taken out and placed in a crucible for crystallization treatment at high temperature to obtain crystals;

[0019] S102, adding 2 parts of triethanolamine into a crucible and stirring evenly, then performing high temperature crystallization treatment, and obtaining a modified catalyst after cooling.

[0020] As a further solution of the present invention: the reaction temperature of the reactor in S101 is 150°C, the reaction time is 30 min, the temperature of the crucible in S101 is 450°C; the temperature of the crucible in S102 is 350°C.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The isopropylhydroxylamine produced by the invention is subjected to catalytic treatment by a modified catalyst. The modified catalyst is prepared by adding an activator and a volume expander to a conventional TS-1 molecular sieve. The activator, the volume expander and the TS-1 molecular sieve have a specific ratio. The activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide in a specific ratio, and the volume expander is composed of triethanolamine. The activator can prevent reactants from being blocked in the pores of the TS-1 molecular sieve, thereby causing the problem of reduced activity. The volume expander can improve the dielectric capacity, pore volume and specific surface area of ​​the TS-1 molecular sieve, reduce the resistance of the reactants in the catalyst, and facilitate diffusion. The two together improve the conversion activity of the TS-1 molecular sieve, so that the isopropylhydroxylamine reacts completely in the production process, thereby improving the isopropylamine conversion rate and the isopropylhydroxylamine selectivity of the produced isopropylhydroxylamine. DETAILED DESCRIPTION

[0023] In an embodiment of the present invention, a method for preparing isopropylhydroxylamine comprises the following steps:

[0024] S1. Oxidation treatment: isopropylamine, deionized water and modified catalyst are placed in a reactor for heating processing, stirred while heating, hydrogen peroxide is added dropwise within a certain period of time, and then continued to stir for oxidation treatment; the reactor processing temperature is 92-98°C, the hydrogen peroxide addition time is 20 minutes, the total stirring time is 70 minutes, the concentration of hydrogen peroxide is 55%, and the mass ratio of isopropylamine to hydrogen peroxide is 2:1; S2. Filtration treatment: the material after the above oxidation treatment is filtered through a filter to filter out the modified catalyst, and the filtrate is placed in The distillation tower is used for distillation treatment, and the isopropylamine aqueous solution is collected in the first temperature section under normal pressure, and the acetone oxime aqueous solution is collected in the second temperature section under vacuum conditions; the first temperature section is 30-55° C., the second temperature section is 60-85° C., and the pressure under vacuum conditions is 0.05 MPa; S3, acetone oxime treatment: the acetone oxime aqueous solution in S2 is concentrated, and then crystallized with a cooling crystallizer to obtain co-produced acetone oxime; S4, isopropylhydroxylamine treatment: the isopropylamine aqueous solution in S2 is cooled, and then crystallized with a cooling crystallizer to obtain isopropylhydroxylamine crystals;

[0025] The modified catalyst in S1 is composed of an activator, a volume expander and TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve; the activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander is composed of triethanolamine; the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 2-4:22:1-3;

[0026] The preparation method of the modified catalyst comprises the following steps:

[0027] S101. Put 0.24 parts of molybdenum trioxide, 2.64 parts of tungsten trioxide, 0.12 parts of calcium oxide and 10 parts of TS-1 molecular sieve into a reactor for reaction while stirring. The reaction temperature is 60°C. Then take out the reactants and place them in a crucible for crystallization treatment at high temperature to obtain crystals. The reaction temperature of the reactor is 150°C, the reaction time is 30 minutes, and the crucible temperature is 450°C. S102. Add 2 parts of triethanolamine into the crucible and stir evenly. Then perform high-temperature crystallization treatment. After cooling, a modified catalyst is obtained. The crucible temperature is 350°C. Embodiment 1

[0028] The modified catalyst in S1 is composed of an activator, a volume expander and TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve; the activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander is composed of triethanolamine; the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 2:22:1;

[0029] The preparation method of the modified catalyst comprises the following steps:

[0030] S101. Put 0.24 parts of molybdenum trioxide, 2.64 parts of tungsten trioxide, 0.12 parts of calcium oxide and 10 parts of TS-1 molecular sieve into a reactor for reaction while stirring. The reaction temperature is 60°C. Then take out the reactants and place them in a crucible for crystallization treatment at high temperature to obtain crystals. The reaction temperature of the reactor is 150°C, the reaction time is 30 minutes, and the crucible temperature is 450°C. S102. Add 2 parts of triethanolamine into the crucible and stir evenly. Then perform high-temperature crystallization treatment. After cooling, a modified catalyst is obtained. The crucible temperature is 350°C. Embodiment 2

[0031] The modified catalyst in S1 is composed of an activator, a volume expander and TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve; the activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander is composed of triethanolamine; the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 2.4:22:1.4;

[0032] The preparation method of the modified catalyst comprises the following steps:

[0033] S101. Put 0.28 parts of molybdenum trioxide, 2.56 parts of tungsten trioxide, 0.16 parts of calcium oxide and 10 parts of TS-1 molecular sieve into a reactor for reaction while stirring. The reaction temperature is 60°C. Then take out the reactants and place them in a crucible for crystallization treatment at high temperature to obtain crystals. The reaction temperature of the reactor is 150°C, the reaction time is 30 minutes, and the crucible temperature is 450°C. S102. Add 2 parts of triethanolamine into the crucible and stir evenly. Then perform high-temperature crystallization treatment. After cooling, a modified catalyst is obtained. The crucible temperature is 350°C. Embodiment 3

[0034] The modified catalyst in S1 is composed of an activator, a volume expander and TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve; the activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander is composed of triethanolamine; the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 2.8:22:1.8;

[0035] The preparation method of the modified catalyst comprises the following steps:

[0036] S101. Put 0.32 parts of molybdenum trioxide, 2.48 parts of tungsten trioxide, 0.20 parts of calcium oxide and 10 parts of TS-1 molecular sieve into a reactor for reaction while stirring. The reaction temperature is 60°C. Then take out the reactants and place them in a crucible for crystallization treatment at high temperature to obtain crystals. The reaction temperature of the reactor is 150°C, the reaction time is 30 minutes, and the crucible temperature is 450°C. S102. Add 2 parts of triethanolamine into the crucible and stir evenly. Then perform high-temperature crystallization treatment. After cooling, a modified catalyst is obtained. The crucible temperature is 350°C. Embodiment 4

[0037] The modified catalyst in S1 is composed of an activator, a volume expander and TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve; the activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander is composed of triethanolamine; the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 3.2:22:2.2;

[0038] The preparation method of the modified catalyst comprises the following steps:

[0039] S101. Put 0.35 parts of molybdenum trioxide, 2.41 parts of tungsten trioxide, 0.24 parts of calcium oxide and 10 parts of TS-1 molecular sieve into a reactor for reaction while stirring. The reaction temperature is 60°C. Then take out the reactants and place them in a crucible for crystallization treatment at high temperature to obtain crystals. The reaction temperature of the reactor is 150°C, the reaction time is 30 minutes, and the crucible temperature is 450°C. S102. Add 2 parts of triethanolamine into the crucible and stir evenly. Then perform high-temperature crystallization treatment. After cooling, a modified catalyst is obtained. The crucible temperature is 350°C. Embodiment 5

[0040] The modified catalyst in S1 is composed of an activator, a volume expander and TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve; the activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander is composed of triethanolamine; the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 3.6:22:2.6;

[0041] The preparation method of the modified catalyst comprises the following steps:

[0042] S101. Put 0.38 parts of molybdenum trioxide, 2.34 parts of tungsten trioxide, 0.28 parts of calcium oxide and 10 parts of TS-1 molecular sieve into a reactor for reaction while stirring. The reaction temperature is 60°C. Then take out the reactants and place them in a crucible for crystallization treatment at high temperature to obtain crystals. The reaction temperature of the reactor is 150°C, the reaction time is 30 minutes, and the crucible temperature is 450°C. S102. Add 2 parts of triethanolamine into the crucible and stir evenly. Then perform high-temperature crystallization treatment. After cooling, a modified catalyst is obtained. The crucible temperature is 350°C. Embodiment 6

[0043] The modified catalyst in S1 is composed of an activator, a volume expander and TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve; the activator is composed of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander is composed of triethanolamine; the mass ratio of molybdenum trioxide, tungsten trioxide and calcium oxide is 4:22:3;

[0044] The preparation method of the modified catalyst comprises the following steps:

[0045] S101. Put 0.41 parts of molybdenum trioxide, 2.28 parts of tungsten trioxide, 0.31 parts of calcium oxide and 10 parts of TS-1 molecular sieve into a reactor for reaction while stirring. The reaction temperature is 60°C. Then take out the reactants and place them in a crucible for crystallization treatment at high temperature to obtain crystals. The reaction temperature of the reactor is 150°C, the reaction time is 30 minutes, and the crucible temperature is 450°C. S102. Add 2 parts of triethanolamine into the crucible and stir evenly. Then perform high-temperature crystallization treatment. After cooling, a modified catalyst is obtained. The crucible temperature is 350°C.

[0046] In order to further illustrate the technical effect of the present invention, the following experiments are performed to verify:

[0047] The catalysts produced in Examples 1, 2, 3, 4, 5 and 6 of the present invention were selected and respectively placed in S1 to S4 of the present invention to produce isopropylhydroxylamine, which are respectively recorded as Experimental Examples A, B, C, D, E and F;

[0048] Only the TS-1 molecular sieve in Example 4 of the present invention is placed in S1 to S4 of the present invention to produce isopropylhydroxylamine, which is recorded as Experimental Example G;

[0049] The isopropylhydroxylamine in Example 3 of the preparation method of N-isopropylhydroxylamine disclosed in the Chinese patent (authorization announcement number CN105152962B) is selected as Experimental Example M, and the modified catalyst produced in Example 4 of the present invention is used to replace the TS-1 catalyst in Example 3 of the Chinese patent to produce isopropylhydroxylamine, which is recorded as Experimental Example N;

[0050] Experimental Examples A, B, C, D, E, F, G, M, and N were tested to determine the production rate of isopropylhydroxylamine, and the following table was prepared:

[0051] It can be concluded from the above table that the conversion rates of isopropylamine in Experimental Examples A, B, C, D, E, F, and N are all greater than or equal to 99.5%, and the conversion rates of isopropylamine in Experimental Examples G and M are both around 99%; the selectivity of isopropylhydroxylamine in Experimental Examples A, B, C, D, E, F, and N is all greater than or equal to 71%, and the selectivity of isopropylhydroxylamine in Experimental Examples G and M is both around 66%;

[0052] From this, it can be analyzed that the conversion rate and selectivity of isopropylhydroxylamine produced by the TS-1 molecular sieve modified with an activator and an expander, such as Experimental Examples A, B, C, D, E, F, and N, are higher than those produced by the TS-1 molecular sieve modified with no activator and expander, such as Experimental Examples G and M.

[0053] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0054] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing isopropylhydroxylamine, It is characterized in that The following steps are involved: S1, oxidation treatment: isopropylamine, deionized water and modified catalyst are placed in a reactor for heating processing, stirred while heating, hydrogen peroxide is added dropwise within a certain period of time, and then continued to stir for oxidation treatment; S2, filtering treatment: filtering the material after the above oxidation treatment through a filter to filter out the modified catalyst, placing the filtrate in a distillation tower for distillation treatment, collecting the isopropylamine aqueous solution in the first temperature section under normal pressure, and collecting the acetone oxime aqueous solution in the second temperature section under vacuum conditions; S3, acetone oxime treatment: concentrating the acetone oxime aqueous solution in S2, and then performing crystallization treatment with a cooling crystallizer to obtain co-produced acetone oxime; S4, isopropylhydroxylamine treatment: cooling the isopropylamine aqueous solution in S2, and then performing crystallization treatment using a cooling crystallizer to obtain isopropylhydroxylamine crystals; The preparation method of the modified catalyst comprises the following steps: S101, 0.24 parts of molybdenum trioxide, 2.64 parts of tungsten trioxide, 0.12 parts of calcium oxide, and 10 parts of TS-1 molecular sieve are put into a reactor to react while stirring, and the reaction temperature is 60° C., and then the reactants are taken out and placed in a crucible for crystallization treatment at high temperature to obtain crystals; S102, adding 2 parts of triethanolamine into a crucible and stirring evenly, then performing a high temperature crystallization treatment, and cooling to obtain a modified catalyst; The reaction temperature of the reactor in S101 is 150° C., the reaction time is 30 min, the temperature of the crucible in S101 is 450° C.; the temperature of the crucible in S102 is 350° C.

2. A method for preparing isopropylhydroxylamine according to claim 1, It is characterized in that The processing temperature of the reactor in S1 is 92-98° C., the dripping time of hydrogen peroxide is 20 min, and the total stirring time is 70 min.

3. A method for preparing isopropylhydroxylamine according to claim 1, It is characterized in that The concentration of hydrogen peroxide in S1 is 55%, and the mass ratio of isopropylamine to hydrogen peroxide is 2:

1.

4. A method for preparing isopropylhydroxylamine according to claim 1, It is characterized in that The first temperature range in S2 is 30-55° C., the second temperature range is 60-85° C., and the pressure under the vacuum condition is 0.05 MPa.

5. A method for preparing isopropylhydroxylamine according to claim 1, It is characterized in that The modified catalyst in S1 is composed of an activator, a volume expander and a TS-1 molecular sieve, wherein the weight proportions of the activator, the volume expander and the TS-1 molecular sieve are as follows: 3 parts of the activator, 2 parts of the volume expander and 10 parts of the TS-1 molecular sieve.

6. A method for preparing isopropylhydroxylamine according to claim 5, It is characterized in that The activator consists of molybdenum trioxide, tungsten trioxide and calcium oxide, and the volume expander consists of triethanolamine.