Continuous preparation system for preparing 2-nitropropane through ammoxidation of acetone

Abstract

The utility model discloses a continuous preparation system for preparing 2-nitropropane through ammoxidation of acetone. The evaporator is provided with a feeding port, a steam outlet and a catalyst outlet, the raw material storage tank is used for storing raw materials, an outlet of the reaction tank is connected with the feeding port of the evaporator, the steam outlet of the evaporator is connected with a rectifying tower, the catalyst outlet of the evaporator is connected with a dryer, and the dryer is connected with the raw material storage tank through a solid material conveying valve. The raw material storage tank is connected with the reaction tank through the metering device, the rectifying tower is provided with a reflux inlet and a discharge outlet, the reflux inlet of the rectifying tower is connected with the raw material storage tank, and the discharge outlet of the rectifying tower is directly used for outputting products. The 2-nitropropane continuous production device has the advantages that acetone, methanol and the TS-1 molecular sieve can be added into the raw material storage tank to be matched with hydrogen peroxide and ammonia water added into the reaction tank so as to achieve the purpose of high conversion rate, continuous production of 2-nitropropane can be achieved, the automation degree is high, the production efficiency is high, and in addition, the separation effect is better.

Description

Technical Field

[0001] The utility model relates to a preparation system for chemical raw materials, in particular to a continuous preparation system for preparing 2-nitropropane by ammoxidation of acetone. Background Art

[0002] 2-Nitropropane is an important raw material in the field of fine chemicals such as drugs, solvents, surfactants, emulsifiers and lubricants. It can be used as a polar solvent for paints, an extractant for stearic acid and saturated glycerides, or for the preparation of 4-chlorophenylnitrobenzene insecticides, bentazon herbicides, etc. At present, the industrial production methods of 2-nitropropane are mainly divided into nitric acid direct oxidation method (CSC method) and nitrogen oxide nitrification method (GP method), both of which have problems with high conversion rate and potential safety hazards.

[0003] In recent years, the use of TS-1 / H2O2's efficient oxidation performance to oxidize acetone or acetone oxime to 2-nitropropane is considered to be a green, economical and safe 2-nitropropane preparation process route, which has been reported in the field of fine chemicals. Chinese invention patent CN115557840A discloses a method for preparing 2-nitropropane and a catalyst used therein. The invention uses acetone oxime, ammonia and hydrogen peroxide as raw materials to prepare 2-nitropropane through an ammoxidation reaction in a solvent. However, in the disclosed technical documents, most of them adopt an intermittent production method. Therefore, although the conversion rate has been improved, there are still problems such as low production efficiency, great safety hazards, and high equipment investment. Therefore, how to solve the above problems has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a continuous preparation system for preparing 2-nitropropane by acetone ammoxidation with high conversion rate, high production efficiency and good safety.

[0005] In order to solve the above technical problems, the utility model discloses a continuous preparation system for preparing 2-nitropropane by ammoxidation of acetone, comprising a reaction tank, an evaporator having a feed inlet, a steam outlet, and a catalyst outlet, and a raw material storage tank for storing raw materials, wherein the outlet of the reaction tank is connected to the feed inlet of the evaporator, the steam outlet of the evaporator is connected to a distillation tower, the catalyst outlet of the evaporator is connected to a dryer, the dryer is connected to the raw material storage tank via a solid material delivery valve, the raw material storage tank is connected to the reaction tank via a metering device, the distillation tower has a reflux port and a discharge port, and the reflux port of the distillation tower is connected to the raw material storage tank, and the discharge port of the distillation tower is directly used for outputting the product.

[0006] The evaporator is a multiple-effect evaporator.

[0007] The reflux port of the distillation tower is arranged at the top of the distillation tower.

[0008] The discharge port of the distillation tower is arranged at the bottom of the distillation tower.

[0009] The metering device is a metering pump.

[0010] The working temperature of the reaction tank is 60-70°C.

[0011] Acetone, methanol and catalyst are added into the raw material storage tank.

[0012] The catalyst is TS-1 molecular sieve.

[0013] The advantages of the utility model are:

[0014] By setting up a complete set of continuous production and preparation system consisting of a reaction tank, a multiple-effect evaporator, a dryer, a raw material storage tank, a distillation tower, etc., not only can acetone, methanol and TS-1 molecular sieve added to the raw material storage tank be matched with hydrogen peroxide and ammonia water added to the reaction tank to achieve the purpose of high conversion rate, but also the continuous production of 2-nitropropane can be achieved. Compared with the traditional intermittent preparation method, it has the advantages of high degree of automation and high production efficiency. In addition, according to the oily characteristics of 2-nitropropane, a two-stage drying method is designed to complete the separation of TS-1 molecular sieve and liquid materials. Compared with the traditional membrane separation method, the separation effect is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The utility model is a structural schematic diagram of a continuous preparation system for preparing 2-nitropropane by acetone ammoxidation. DETAILED DESCRIPTION

[0016] The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0017] As shown in the figure, the continuous preparation system of acetone ammoxidation to 2-nitropropane of the utility model comprises a reaction tank 1, an evaporator 2, a dryer 3, a solid material delivery valve 4, a raw material storage tank 5, a metering device 6 and a distillation tower 7, wherein the reaction tank 1 is used to add acetone, methanol and a catalyst, the evaporator 2 has a feed inlet, a steam outlet and a catalyst outlet, the raw material storage tank 5 is used to store raw materials, and the distillation tower 7 has a reflux port and a discharge port. As can be seen from the figure, in this embodiment, the reflux port of the distillation tower 7 is arranged at the top of the distillation tower, and the discharge port of the distillation tower 7 is arranged at the bottom of the distillation tower. The specific connection structure of the preparation system is: the outlet of the reaction tank 1 is connected to the feed inlet of the evaporator 2 through a reaction tank pipeline, thereby allowing the discharge of the reaction tank 1 to enter the evaporator 2; the steam outlet of the evaporator 2 is connected to the distillation tower 7 through a steam pipeline, so that the steam vaporized by the evaporator 2 can enter the evaporator 2. Steam enters the distillation tower 7; the catalyst outlet of the evaporator 2 is connected to the dryer 3 through a catalyst pipeline, so that the catalyst evaporated by the evaporator 2 can enter the dryer 3; the dryer 3 is connected to the raw material storage tank 5 through a solid material conveying pipeline, and a solid material conveying valve 4 is provided on the solid material conveying pipeline, so that the catalyst dried by the dryer 3 can enter the raw material storage tank 5 through the solid material conveying valve 4; the raw material storage tank 5 is connected to the reaction tank 1 through a raw material conveying pipeline, and a metering device 6 is provided on the raw material conveying pipeline, so that the material in the raw material storage tank 5 can enter the reaction tank 1 after being measured by the metering device; the reflux port of the distillation tower 7 is connected to the raw material storage tank 5 through a reflux pipeline, so that the light component at the top of the distillation tower 7 can be refluxed to the raw material storage tank 5, and the discharge port of the distillation tower 7 is directly used for the output of the product, thereby obtaining high-purity 2-nitropropane.

[0018] Furthermore, the evaporator 2 is a multiple-effect evaporator, the metering device is a metering pump, the working temperature of the reaction tank 1 is 60-70° C., and preferably, the catalyst used in the raw material storage tank 5 is TS-1 molecular sieve.

[0019] The working and usage process is as follows:

[0020] (1) Add acetone, methanol and TS-1 molecular sieve into the raw material storage tank 5;

[0021] (2) Heat the reaction tank 1 to 65°C, start the metering pump, and inject the acetone, methanol and TS-1 molecular sieve in the raw material storage tank 5 into the reaction tank 1;

[0022] (3) Injecting ammonia water and hydrogen peroxide into the reaction tank 1 simultaneously;

[0023] (4) After the mixed material reacts in the reaction tank 1 for 2 hours, it enters the multiple-effect evaporator;

[0024] (5) The steam evaporated from the multiple-effect evaporator 2 enters the distillation tower 7 for distillation;

[0025] (6) The semi-dried solid material in the multiple-effect evaporator enters the dryer 3, and after being dried at 150°C, enters the raw material storage tank 5 through the solid material delivery valve 4;

[0026] (7) The mixed material in the raw material tank 5 then enters the reaction tank through a metering pump;

[0027] (8) The light components at the top of the distillation tower 7 are refluxed to the raw material tank 5;

[0028] (9) High-purity 2-nitropropane is obtained at the bottom of the distillation tower 7.

[0029] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A continuous preparation system for 2-nitropropane by ammoxidation of acetone, characterized in that: The invention comprises a reaction tank (1), an evaporator (2) having a feed inlet, a steam outlet and a catalyst outlet, and a raw material storage tank (5) for storing raw materials, wherein the outlet of the reaction tank (1) is connected to the feed inlet of the evaporator (2), the steam outlet of the evaporator (2) is connected to a distillation tower (7), the catalyst outlet of the evaporator (2) is connected to a dryer (3), the dryer (3) is connected to the raw material storage tank (5) via a solid material delivery valve (4), the raw material storage tank (5) is connected to the reaction tank (1) via a metering device (6), the distillation tower (7) has a reflux port and a discharge port, and the reflux port of the distillation tower (7) is connected to the raw material storage tank (5), and the discharge port of the distillation tower (7) is directly used for outputting products.

2. The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation according to claim 1, characterized in that: The evaporator (2) is a multiple-effect evaporator.

3. The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation according to claim 1 or 2, characterized in that: The reflux port of the distillation tower (7) is arranged at the top of the distillation tower.

4. The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation according to claim 3, characterized in that: The discharge port of the distillation tower (7) is arranged at the bottom of the distillation tower.

5. The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation according to claim 1, 2 or 4, characterized in that: The metering device is a metering pump.

6. The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation according to claim 5, characterized in that: The working temperature of the reaction tank (1) is 60-70°C.

7. The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation according to claim 1, characterized in that: Acetone, methanol and a catalyst are added into the raw material storage tank (5).

8. The continuous preparation system for preparing 2-nitropropane by acetone ammoxidation according to claim 7, characterized in that: The catalyst is TS-1 molecular sieve.

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