Metal-free catalytic oxidation system, an oxygenation method and a method for producing benzoic acid derivatives

Abstract

A metal-free catalytic oxidation system, an oxygenation method and a method for producing benzoic acid derivatives. The system includes a feed device; a tubular reactor; a plurality of venturi nozzles mounted on the tubular reactor at intervals; a tubular filter; a discharge device for a solid phase product; and an intermediate tank for reaction mixture. A low-pressure zone is formed at an output end of each of the plurality of venturi nozzles, and an oxygen inlet corresponds to the low-pressure zone; the tubular filter comprises an inner tube and an outer tube connected to each other, where the inner tube is provided with small holes for solid-liquid separation; the discharge device for the solid phase product is located at an end of the inner tube; and the intermediate tank for reaction mixture is connected to the outer tube of the tubular filter through a pipeline.

Claims

1. A metal-free catalytic oxidation system, comprising: a feed device; a tubular reactor; a plurality of venturi nozzles mounted on the tubular reactor at intervals; a tubular filter; a discharge device for a solid phase product connected to a solid phase output end of the tubular filter; and an intermediate tank for reaction mixture connected to a liquid phase output end of the tubular filter; wherein a low-pressure zone is formed at an output end of each of the plurality of venturi nozzles, and an oxygen inlet corresponds to the low-pressure zone; the tubular filter comprises an inner tube and an outer tube connected to each other, wherein the inner tube is provided with small holes for solid-liquid separation; the discharge device for the solid phase product is located at an end of the inner tube; and the intermediate tank for reaction mixture is connected to the outer tube of the tubular filter through a pipeline.

2. The system of claim 1, wherein the feed device comprises a basic material feed device and a nitric acid feed device.

3. The system of claim 1, wherein a heat exchange system in the form of a sleeve is provided outside the tubular reactor, and a heat exchange medium flows in a gap between the heat exchange system and the tubular reactor.

4. The system of claim 1, wherein the plurality of venturi nozzles are spaced apart on the tubular reactor.

5. The system of claim 1, wherein the discharge device for the solid phase product is a screw conveyor.

6. The system of claim 1, wherein the intermediate tank for reaction mixture is provided with two bleeder tubes, where one is connected to an effluent treatment system, and the other is connected to the tubular reactor.

7. The system of claim 1, wherein the tubular reactor is provided with a circulating feed pump.

8. An oxygenation method using the metal-free catalytic oxidation system of claim 1.

9. A method for producing benzoic acid derivatives by oxygenation using the metal-free catalytic oxidation system of claim 6, comprising: 1) opening a nitric acid storage tank to add a certain amount of a nitric acid and then closing the nitric acid storage tank; and turning on the circulating feed pump to start circulation of materials in the system; 2) turning on a heat exchange system of the tubular reactor to heat the tubular reactor; 3) opening a raw material storage tank to introduce a raw material into the tubular reactor; 4) opening the nitric acid storage tank again to introduce the nitric acid into the tubular reactor; 5) opening the plurality of venturi nozzles to feed oxygen, the raw material and the nitric acid into the tubular reactor for reaction; 6) opening the intermediate tank for the reaction mixture to discharge excess effluent in the tubular reactor; and 7) turning on the screw conveyor to transport finished product in the tubular filter into a product storage tank.

10. A method for producing benzoic acid derivatives by oxygenation using the metal-free catalytic oxidation system of claim 1, wherein the raw material is any one of tert-butyltoluene, nitrotoluene, p-chlorotoluene, ##STR00012## 2,4-dimethyl nitrobenzene, ##STR00013##

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The FIGURE is a schematic diagram of a metal-free catalytic oxidation system according to the present disclosure.

(2) In the drawings: 1 raw material storage tank, 2 nitric acid storage tank, 3 venturi nozzle, 4 tubular reactor, 5 tubular filter, 6 screw conveyor, 7 product storage tank, 8 intermediate tank for reaction mixture, 9 circulating feed pump, 10 effluent treatment system.

DETAILED DESCRIPTION OF EMBODIMENTS

(3) The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the drawings. It is apparent that the embodiments disclosed below are only some embodiments of the present disclosure, not all of the embodiments. Any other embodiments can be made by those of ordinary skill in the art based on the embodiments of the present disclosure without creative work, which will fall with the scope of the present disclosure.

Embodiment 1

(4) 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 25% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system.

(5) 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C.

(6) 3) Open the raw material storage tank 1 to introduce the p-tert-butyltoluene into the tubular reactor 4 at a feed rate of 100 kg/h.

(7) 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h.

(8) 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 18.1 m.sup.3/h.

(9) 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h.

(10) 7) Open the screw conveyor 6 to transport the synthesized p-tert-butylbenzoic acid in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography. A purity of the p-tert-butylbenzoic acid is 99.5%; a production rate is 119.3 kg/h; and a molar yield is 99.2%.

(11) 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 24.5%. When the concentration of nitric acid is lower than 24.5%, the feed rate of nitric acid solution needs to be increased appropriately.

Embodiment 2

(12) 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 30% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system.

(13) 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C.

(14) 3) Open the raw material storage tank 1 to introduce the p-nitrotoluene into the tubular reactor 4 at a feed rate of 100 kg/h.

(15) 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h.

(16) 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 19.4 m.sup.3/h.

(17) 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h.

(18) 7) Open the screw conveyor 6 to transport the synthesized p-nitrobenzoic acid in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography. A purity of the p-nitrobenzoic acid is 99.8%; a production rate is 120.4 kg/h; and a molar yield is 99.6%.

(19) 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 29.4%. When the concentration of nitric acid is lower than 29.4%, the feed rate of nitric acid solution needs to be increased appropriately.

Embodiment 3

(20) 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 28% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system.

(21) 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C.

(22) 3) Open the raw material storage tank 1 to introduce the p-chlorotoluene into the tubular reactor 4 at a feed rate of 100 kg/h.

(23) 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h. 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 21 m.sup.3/h.

(24) 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h.

(25) 7) Open the screw conveyor 6 to transport the synthesized parachlorobenzoic-acid in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography. A purity of the parachlorobenzoic-acid is 98.5%; a production rate is 124 kg/h; and a molar yield is 99.7%.

(26) 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 27.4%. When the concentration of nitric acid is lower than 27.4%, the feed rate of nitric acid solution needs to be increased appropriately.

Embodiment 4

(27) 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 25% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system.

(28) 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C.

(29) 3) Open the raw material storage tank 1 to introduce

(30) ##STR00003##
into the tubular reactor 4 at a feed rate of 100 kg/h.

(31) 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h.

(32) 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 12.6 m.sup.3/h.

(33) 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h.

(34) 7) Open the screw conveyor 6 to transport the synthesized

(35) ##STR00004##
in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography. A purity of

(36) ##STR00005##
is 99.2%; a production rate is 98.2 kg/h; and a molar yield is 98.8%.

(37) 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 24.5%. When the concentration of nitric acid is lower than 24.5%, the feed rate of nitric acid solution needs to be increased appropriately.

Embodiment 5

(38) 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 30% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system.

(39) 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C.

(40) 3) Open the raw material storage tank 1 to introduce the 2, 4-dimethyl nitrobenzene into the tubular reactor 4 at a feed rate of 100 kg/h.

(41) 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h.

(42) 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 17.5 m.sup.3/h.

(43) 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h.

(44) 7) Open the screw conveyor 6 to transport the synthesized 3-methyl-4-nitrobenzoic acid in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography. A purity of the 3-methyl-4-nitrobenzoic acid is 99.5%; a production rate is 118.1 kg/h; and a molar yield is 99.5%.

(45) 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 29.4%. When the concentration of nitric acid is lower than 29.4%, the feed rate of nitric acid solution needs to be increased appropriately.

Embodiment 6

(46) 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 35% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system.

(47) 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C.

(48) 3) Open the raw material storage tank 1 to introduce

(49) ##STR00006##
into the tubular reactor 4 at a feed rate of 100 kg/h.

(50) 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h.

(51) 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 14.4 m.sup.3/h.

(52) 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h.

(53) 7) Open the screw conveyor 6 to transport the synthesized

(54) ##STR00007##
in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography. A purity of

(55) ##STR00008##
is 99.6%; a production rate is 107.5 kg/h; and a molar yield is 99.1%.

(56) 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 34.3%. When the concentration of nitric acid is lower than 34.3%, the feed rate of nitric acid solution needs to be increased appropriately.

Embodiment 7

(57) 1) Open the nitric acid storage tank, and close it after adding 100 kg of a 65% nitric acid solution to the system, and then open the circulating feed pump 9 to start the circulation of materials in the system.

(58) 2) Open the tubular reactor 4 and heat the tubular reactor 4 to raise the temperature of the system to 90° C.

(59) 3) Open the raw material storage tank 1 to introduce

(60) ##STR00009##
into the tubular reactor 4 at a feed rate of 100 kg/h.

(61) 4) Open the nitric acid solution storage tank again to continue to introduce the nitric acid solution into the tubular reactor 4 at a feed rate of 33 kg/h.

(62) 5) Open all venturi nozzles 3 to feed oxygen into the tubular reactor 4 at a total feed rate of 9.1 m.sup.3/h.

(63) 6) Open the intermediate tank 8 for the reaction mixture to discharge the excess effluent in the tubular reactor 4 at a discharge rate of 30 kg/h.

(64) ##STR00010##

(65) 7) Open the screw conveyor 6 to transport the synthesized in the tubular filter 5 into the product storage tank 7; wash the product in the storage tank with water and dry it; and finally analyze it by a high performance liquid chromatography; A purity of

(66) ##STR00011##
is 99.5%; a production rate is 95.3 kg/h; and a molar yield is 96.5%.

(67) 8) Check and keep the concentration of nitric acid in the reaction mixture in the intermediate tank 8 every hour at no less than 63.7%. When the concentration of nitric acid is lower than 63.7%, the feed rate of nitric acid solution needs to be increased appropriately.

(68) The above-mentioned embodiments are only for illustrative purposes, and are not intended to limit the scope of the present disclosure. Any improvements, changes, modifications without departing from the spirit of the present invention shall fall within the scope of the present invention.