CN116328702A

CN116328702A - Oxidation device for producing hydrogen peroxide

Info

Publication number: CN116328702A
Application number: CN202310000254.2A
Authority: CN
Inventors: 申敬敬; 庞飞; 许颖睿; 丁秋霞; 白立光; 马俊; 赵晓东
Original assignee: Liming Research Institute of Chemical Industry Co Ltd
Current assignee: Liming Research Institute of Chemical Industry Co Ltd
Priority date: 2023-01-02
Filing date: 2023-01-02
Publication date: 2023-06-27

Abstract

The invention discloses an oxidation device for producing hydrogen peroxide, which comprises an oxidation tower, a microbubble generator and a post-reactor, wherein a liquid inlet A is arranged on the side surface of the upper part of the oxidation tower, a liquid outlet A and a gas inlet A are arranged on the lower part of the oxidation tower, a gas outlet A is arranged at the top of the oxidation tower, an arched tower plate, a liquid distributor, a gas distributor and a gas-liquid separator are arranged in the oxidation tower, the liquid outlet A is positioned below the gas distributor, uniformly distributed holes are arranged on the arched tower plate, and adjacent arched tower plates are alternately distributed; the oxidation liquid and fresh air flowing out from the liquid outlet A of the oxidation tower are mixed by a micro-bubble generator to form micro-bubble flow, the micro-bubble flow enters the post-reactor, and the gas coming out from the top of the post-reactor is mixed with the fresh air and then enters the oxidation tower. The oxidation device can improve the conversion rate of the reaction, reduce the volume of the reactor, improve the oxidation yield, reduce the tail oxygen content and improve the safety.

Description

Oxidation device for producing hydrogen peroxide

Technical Field

The invention relates to equipment and a process for gas-liquid two-phase reaction, in particular to an oxidation device for producing hydrogen peroxide.

Background

At present, the preparation of hydrogen peroxide at home and abroad mainly adopts an anthraquinone method preparation process, the process takes alkylanthraquinone (AQ, mainly 2-alkylanthraquinone) as a carrier, and proper solvents for respectively dissolving anthraquinone and anthrahydroquinone, substances for regulating the pH of the solution and the like are selected to jointly form working solution, and the whole preparation process generally comprises the procedures of hydrogenation, oxidation, extraction, purification and the like. The solvent for dissolving anthraquinone generally adopts heavy aromatic hydrocarbon extracted from petroleum industry, C9 aromatic hydrocarbon is adopted in China, and is a mixture containing trimethylbenzene, methyl ethylbenzene and the like, and C10 aromatic hydrocarbon is adopted in China. The solvent for dissolving anthrahydroquinone can be one or more selected from o-methylcyclohexyl acetate, diisobutyl methanol, trioctyl phosphate, tetrabutyl urea, etc. In the hydrogenation step, anthraquinones are hydrogenated to obtain anthrahydroquinones under the action of a catalyst, and the working solution becomes a hydrogenated solution. Then the hydrogenation solution is oxidized by the gas containing oxygen to H in the oxidation step ₂ O ₂ And anthraquinone oxidizing liquid, wherein the gas containing oxygen can be pure oxygen or oxygen-enriched air, and compressed air is selected in practice for reducing cost and safety.

In the oxidation process, the hydrogenation liquid and air generally react in a parallel flow upward flow mode, and the oxygen content in the air is only about 21%, the reaction pressure in the oxidation tower is 0.18-0.4 MPa, the reaction temperature is 40-55 ℃, the reaction condition is mild, the oxygen concentration at the gas-liquid interface is low, and the reaction speed is low. In order to improve the conversion rate of the reaction, the reaction is industrially carried out in a mode of connecting two towers in series or connecting three towers in series, wherein the towers are mainly empty towers except for a gas distributor, a redistributor and a heat exchanger, and even if the oxidation tower is subjected to long reaction time, the oxidation yield is still about 90-95%, and the tail oxygen content is about 6%. The prior industry has the defects of low oxidation yield, high tail oxygen content and the like. Compared with parallel flow, the countercurrent contact of the gas phase and the liquid phase has the advantage of high mass transfer rate.

Disclosure of Invention

The invention aims to provide an oxidation device for producing hydrogen peroxide, wherein hydrogenated liquid of the device flows downwards after entering from the upper part of an oxidation tower through a liquid distributor, air flows upwards after entering from the lower part of the oxidation tower through a gas distributor, gas-liquid two phases are in countercurrent contact macroscopically, in addition, due to the influence of a bow-shaped tower plate, liquid flows in an S-shaped cross flow mode in the oxidation tower, the flow path of working liquid in the oxidation tower is prolonged, gas and liquid can be in more sufficient contact, and at the bottom of the oxidation tower, the air enters the oxidation tower in the form of microbubbles after passing through the gas distributor with a micropore structure and contacts with hydrogenated liquid with lower reactant concentration, so that the conversion rate of reaction is improved, and the volume of the oxidation tower is reduced; in addition, the tail oxygen content of the air at the outlet of the oxidation tower can be further reduced after passing through the pre-reactor, and the conversion rate of the hydrogenated liquid and the yield of the hydrogen peroxide can be further improved after the working solution at the outlet of the oxidation tower passes through the post-reactor, so that the economic benefit of the whole device is improved.

The aim of the invention is realized by the following technical scheme:

an oxidation device for producing hydrogen peroxide is characterized by comprising an oxidation tower 101, a microbubble generator 201 and a post-reactor 202, wherein a liquid inlet A111 is arranged on the side surface of the upper part of the oxidation tower 101, a liquid outlet A112 and a gas inlet A113 are arranged on the lower part of the oxidation tower, a gas outlet A114 is arranged on the top of the oxidation tower, an arched tower plate 102, a liquid distributor 103, a gas distributor 104 and a gas-liquid separator 105 are arranged in the oxidation tower 101, the liquid outlet A112 is positioned below the gas distributor 104, uniformly distributed holes are arranged on the arched tower plates 102, and adjacent arched tower plates 102 are alternately distributed; the oxidation liquid flowing out of the liquid outlet A (112) of the oxidation tower (101) and part of fresh air are mixed by a micro-bubble generator (201) to form micro-bubble flow, the micro-bubble flow enters a post-reactor (202), and the gas coming out of the top of the post-reactor (202) is mixed with the fresh air and then enters the oxidation tower (101).

Preferably, the fresh air entering the microbubble generator (201) is used in an amount of not more than 50%, preferably 10 to 30%, of the total air amount of the oxidation tower main body (101).

Preferably, the microbubble generator (201) is made of a venturi jet device, a metal sintering microporous tube, a ceramic sintering microporous tube, a microporous plate or a microporous membrane, or forms a microbubble flow by a pressurized dissolved air release method and a tangential rotational flow method.

The gas distributor 104 is a gas distributor having a microporous structure, wherein the microporous structure is preferably a metal sintered microporous tube, a ceramic sintered microporous tube, a microporous membrane tube or a microchannel with a pore diameter of 0.01-50 μm, and the gas distributor 104 allows gas to enter the oxidation tower 101 in the form of microbubbles through the microporous structure.

The distance between the first arched tower plate 102 above the gas distributor 104 and the gas distributor 104 is 2-10 m, and the distance between adjacent arched tower plates 102 is 50 cm-200 cm; preferably, the first arched tray 102 above the gas distributor 104 is 3-5 m away from the gas distributor 104, and the distance between adjacent arched trays 102 is 80 cm-150 cm.

Preferably, the chord length of the arched tower plate (102) accounts for 20% -90% of the diameter of the tower body, and the area of the arched tower plate (102) accounts for more than half of the cross section area of the oxidation tower (101).

Preferably, the shape of the holes on the arched tower plate (102) is round or tongue, the size of the round holes is 1 mm-30 mm, and the aperture ratio is 0.1% -10%; the aperture ratio of the tongue-shaped hole is 0.1% -10%.

Preferably, the oxidation device is provided with a pre-reactor 301, a liquid inlet B311 is arranged at the upper part of the side surface of the pre-reactor 301, a gas outlet B314 is arranged at the top, a gas inlet B313 is arranged at the bottom, a liquid outlet B312 is arranged at the lower part of the side surface, the gas from the oxidation tower 101 enters from the bottom of the pre-reactor 301 and reacts with the working solution, and the reacted gas enters an oxidation tail gas condenser; preferably 10-100% of the gas exiting the oxidation column 101 enters the pre-reactor 301;

preferably, the main body of the pre-reactor 301 is a cuboid, the left side and the right side are arc surfaces, the liquid inlet B311 and the liquid outlet B312 are on the arc surfaces, and the length of the cuboid is more than 3 times of the width.

The invention has the following beneficial effects:

(1) According to the invention, the oxidation reaction of the anthrahydroquinone is carried out in a mode of countercurrent contact of gas and liquid phases, the liquid main body and the gas flow in a cross flow manner between the arched tower plates, the gas phase is divided into smaller bubbles again by the arched tower plates in the oxidation tower, and compared with the traditional countercurrent contact of the gas phase and the liquid phase, the method has the advantages of high mass transfer driving force and high mass transfer rate, and is beneficial to improving the oxidation yield and reducing the tail oxygen content; in addition, the gas at the bottom of the oxidation tower enters the oxidation tower in the form of micro bubbles through a gas distributor with a micropore structure, so that the contact area of gas and liquid phases can be remarkably increased, and the conversion rate of anthrahydroquinones is improved.

(2) The invention additionally adds a pre-reactor and a post-reactor before and after the original oxidation tower; the interior of the post reactor is in a micro-bubble state, the contact area of the gas phase and the liquid phase is large, the oxidation yield is further improved, the tail oxygen content is reduced, the safety of an oxidation system of the hydrogen peroxide process by an anthraquinone method is improved, the tail oxygen content can be obviously reduced by the arrangement of the pre-reactor, and the economic benefit of the whole device is improved.

Drawings

FIG. 1 is a schematic view of an oxidation unit containing a post-reactor for producing hydrogen peroxide in accordance with the present invention;

FIG. 2 is a schematic diagram of a countercurrent oxidation apparatus containing a pre-reactor and a post-reactor for producing hydrogen peroxide in accordance with the present invention;

FIG. 3 is a circular perforated arcuate tray of the present invention;

FIG. 4 is an arcuate tray of the open-tongue aperture of the present invention;

in the figure: 101. an oxidation tower; 102. arcuate trays; 103. a liquid distributor; 104. a gas distributor; 105. a gas-liquid separator; 201. a microbubble generator; 202. a post-reactor; 301. a pre-reactor; 111. a liquid inlet A; 112. a liquid outlet A; 113. a gas inlet A; 114. a gas outlet A; 311. a liquid inlet B; 312. a liquid outlet B; 313. a gas inlet B; 314. a gas outlet B; 1021. the chords of the arcuate trays.

Detailed Description

The invention is further illustrated by the following examples, which are given by way of illustration only and are not intended to limit the scope of the invention.

In fig. 1, gas enters from a gas inlet a113, is distributed by a gas distributor 104, enters into an oxidation tower 101, flows upwards, enters from a liquid inlet a111, enters into the oxidation tower 101 after being distributed by a liquid distributor 103, flows downwards, and macroscopically forms countercurrent contact of gas and liquid phases and reacts in the oxidation tower 101, wherein the reaction temperature is 40-65 ℃, the reaction pressure is 0.10-1.0 MPa, and then the gas leaves the oxidation tower 101 from a gas outlet a114 at the top of the oxidation tower after passing through a gas-liquid separator 105; the liquid leaves the oxidation tower 101 through a liquid outlet A112 at the bottom of the oxidation tower 101, and is mixed with part of fresh air through a micro-bubble generator 201 to form a micro-bubble flow, the micro-bubble flow enters a post-reactor 202 for further reaction, the part of fresh air does not exceed 50% of the total air quantity of the oxidation tower 101, the further reacted oxidation liquid enters a heat exchanger or enters the next process, and the air reacted in the post-reactor 202 is mixed with the air to be introduced into the oxidation tower 101 and then enters the oxidation tower 101.

In fig. 2, the working solution enters the pre-reactor 301 before entering the oxidation tower 101, 10-100% of the air coming out from the gas outlet a at the top of the oxidation tower 101 enters the bottom of the pre-reactor 301, is distributed by the gas distributor and then contacts with the working solution in a countercurrent manner to react, the reacted air enters the oxidation tail gas condenser, and the reacted working solution enters the oxidation tower 101.

Example 1

The oxidation device designed according to the invention, as shown in figure 1, comprises an oxidation tower 101, a arched tower plate 102, a liquid distributor 103, a gas distributor 104 and a gas-liquid separator 105, wherein a liquid inlet A111 is arranged at the upper part of the oxidation tower 101, a liquid outlet A112 is arranged at the lower part of the oxidation tower 101, a gas inlet A113 is arranged at the lower part of the oxidation tower 101, a gas outlet A114 is arranged at the top of the oxidation tower 101, gas enters from the gas inlet A113, enters the oxidation tower 101 after being distributed by the gas distributor 104, flows upwards, enters from the liquid inlet A111, enters the oxidation tower 101 after being distributed by the liquid distributor 103, flows downwards, macroscopically gas-liquid two phases are in countercurrent contact and react in the oxidation tower 101, and then the liquid passes through the liquid at the bottom of the oxidation tower 101The outlet 102 leaves the oxidation tower 101, and the gas passes through the gas-liquid separator 105 and then leaves the oxidation tower 101 from the gas outlet 114 at the top of the oxidation tower; the gas distributor 104 is provided with a plurality of holes with the aperture of 1 mm, and the aperture ratio is 3%; the chord length of the arched tower plates is 20% of the diameter of the oxidation tower 101, the adjacent arched tower plates are alternately distributed in an S shape, and the distance between the adjacent arched tower plates is 200 cm; circular holes are uniformly distributed on the arched tower plate, the size of the holes is 5 mm, and the aperture ratio is 5%; a post-reactor 202 is arranged after the working solution exits the oxidation tower 101, the oxidation solution after exiting the gas-liquid separator 103 of the oxidation tower 101 is mixed with part of fresh air through a micro-bubble generator 201 to form a micro-bubble flow, the micro-bubble flow enters the post-reactor 202 for further reaction, the part of fresh air is 50% of the total air amount entering the oxidation tower 101, the oxidation solution for further reaction enters the next process, and the air reacted in the post-reactor 202 is mixed with the air to enter the oxidation tower 101 and then enters the oxidation tower 101; the flow rate of the working solution is 930 and 930 m ³ The oxidation reaction temperature is 50 ℃, the air inlet pressure is 0.4 MPa, the apparent residence time of the working solution is 28 min, and the air flow is 30930 Nm ³ At/h, the oxidation yield was 98.1% and the tail oxygen content was 5.4%.

Example 2

Other design and operation steps were identical to those of example 1, except that the air flow was 27360 Nm ³ At/h, the result obtained was an oxidation yield of 97.7% and a tail oxygen content of 3.0%.

Example 3

Other design and operation steps are the same as in example 1, except that the oxidation liquid from the gas-liquid separator 103 of the oxidation tower 101 is mixed with part of fresh air by the microbubble generator 201 to form a microbubble flow, and the microbubble flow enters the post-reactor 202 to further react, wherein the part of fresh air is 30% of the total air amount entering the oxidation tower 101; when the air flow is 30930 and 30930 Nm ³ At/h, the result obtained was an oxidation yield of 98.0% and a tail oxygen content of 5.4%.

Example 4

Other design and operation steps are the same as in example 1, except that the oxygen is taken out of the gas-liquid separator 103 of the oxidation column 101The chemical solution and part of fresh air are mixed through a micro-bubble generator 201 to form micro-bubble flow, and then enter a post-reactor 202 for further reaction, wherein the part of fresh air is 10% of the total air entering an oxidation tower 101; when the air flow is 30930 and 30930 Nm ³ At/h, the result obtained was an oxidation yield of 97.5% and a tail oxygen content of 5.5%.

Example 5

Other design and operation steps were consistent with example 1 except that gas distributor 104 was a metal sintered microporous tube with a pore size of 0.1 μm, and that the first arcuate tray 102 above gas distributor 104 was a distance of 5 m from gas distributor 104; the apparent residence time of the working solution is 28 min, and the air flow rate is 30930 Nm ³ At/h, the oxidation yield was 98.8% and the tail oxygen content was 5.2%.

Example 6

Other design and operation steps were consistent with example 3 except that when the air flow was 27220 Nm ³ At/h, the result obtained was an oxidation yield of 98.3% and a tail oxygen content of 2.7%.

Example 7

Other designs and operating procedures were consistent with example 3 except that the chord length of the arcuate tray 102 was 90% of the column diameter; the spacing between adjacent arched trays is 30 cm; air flow of 27220 and 27220 Nm ³ At/h, the oxidation yield was 98.4% and the tail oxygen content was 2.7%.

Example 8

Other designs and operating procedures were consistent with example 3 except that the arcuate tray 102 had a chord length of 50% of the column diameter; the spacing between adjacent arched trays is 80 cm; air flow of 27220 and 27220 Nm ³ At/h, the oxidation yield was 99.0% and the tail oxygen content was 2.5%.

Example 9

Other design and operation steps are the same as in example 8, except that the working solution is first a pre-reactor 301 before entering the oxidation tower 101, 50% of the air from the oxidation tower 101 enters the bottom of the pre-reactor 301, and after being distributed by the gas distributor, the working solution reacts with the air, and the reacted air enters the oxidation tail gas condenser; air flow rate of 26010 Nm ³ At/h, the oxidation yield was99.1% and tail oxygen content of 1.5%.

Comparative example 1

A conventional double-tower serial oxidation tower is selected, wherein the conventional double-tower serial oxidation tower comprises an upper tower and a lower tower, a gas-liquid separator is arranged at the top of each of the upper tower and the lower tower, hydrogenated liquid enters from the lower part of the upper tower, gas-liquid parallel flow upwards reacts, then enters the lower part of the lower tower after being separated by the gas-liquid separator, and after gas-liquid parallel flow upwards reacts again, leaves from the upper part of the lower tower after gas-liquid separation, and enters an extraction section; air enters from the lower part of the lower tower, enters the lower part of the upper tower after being subjected to gas-liquid separation from the upper part of the lower tower, and enters the tail gas treatment part after being subjected to gas-liquid separation from the upper part of the upper tower; the flow rate of the working solution is 930 and 930 m ³ The oxidation reaction temperature is 50 ℃, the air inlet pressure is 0.4 MPa, the apparent residence time of the working solution is 28 min, and the air flow is 30930 Nm ³ And/h, the oxidation yield is 92.1%, and the tail oxygen content is 6.5%.

Comparative example 2

Otherwise, the same as in example 1 was conducted except that the microbubble generator 201 and the post-reactor 202 were not provided; the flow rate of the working solution is 930 and 930 m ³ The oxidation reaction temperature is 50 ℃, the air inlet pressure is 0.4 MPa, the apparent residence time of the working solution is 28 min, and the air flow is 30930 Nm ³ At/h, the oxidation yield was 96.2% and the tail oxygen content was 5.7%.

Comparative example 3

Other design and operation steps are the same as in example 1, except that the oxidation liquid from the gas-liquid separator 103 of the oxidation tower 101 is mixed with part of fresh air by the microbubble generator 201 to form a microbubble flow, and the microbubble flow enters the post-reactor 202 to further react, wherein the part of fresh air is 60% of the total air amount entering the oxidation tower 101; when the air flow is 30930 and 30930 Nm ³ At/h, the result obtained was an oxidation yield of 97.6% and a tail oxygen content of 5.4%.

Claims

1. The oxidation device for producing hydrogen peroxide is characterized by comprising an oxidation tower (101), a microbubble generator (201) and a post-reactor (202), wherein a liquid inlet A (111) is arranged on the side surface of the upper part of the oxidation tower (101), a liquid outlet A (112) and a gas inlet A (113) are arranged on the lower part of the oxidation tower, a gas outlet A (114) is arranged on the top of the oxidation tower, an arched tower plate (102), a liquid distributor (103), a gas distributor (104) and a gas-liquid separator (105) are arranged in the oxidation tower (101), the liquid outlet A (112) is positioned below the gas distributor (104), uniformly distributed holes are formed in the arched tower plate (102), and adjacent arched tower plates (102) are alternately distributed; the oxidation liquid flowing out of the liquid outlet A (112) of the oxidation tower (101) and part of fresh air are mixed by a micro-bubble generator (201) to form micro-bubble flow, the micro-bubble flow enters a post-reactor (202), and the gas coming out of the top of the post-reactor (202) is mixed with the fresh air and then enters the oxidation tower (101).

2. An oxidation device according to claim 1, characterized in that the fresh air quantity entering the microbubble generator (201) is not more than 50%, preferably 10-30%, of the total air quantity of the oxidation tower (101).

3. The oxidizing apparatus according to claim 1 or 2, wherein the microbubble generator (201) is made of a venturi jet, a metal sintered microporous tube, a ceramic sintered microporous tube, a microporous plate, a microporous membrane, or the like, or forms a microbubble flow by a pressurized gas-dissolving gas-releasing method, a tangential swirling method, or the like.

4. An oxidation device according to claim 1, wherein the gas distributor (104) is a gas distributor having a microporous structure.

5. The oxidation apparatus according to claim 4, wherein the microporous structure is a metal sintered microporous tube, a ceramic sintered microporous tube, a microporous membrane tube or a microchannel having a pore diameter of preferably 0.01 to 50 μm, and the gas distributor (104) introduces the gas into the oxidation tower (101) in the form of microbubbles through the microporous structure.

6. The oxidation device according to claim 1 or 4, wherein the first arched tray (102) above the gas distributor (104) is 2-10 m away from the gas distributor (104), and the distance between adjacent arched trays (102) is 50 cm-200 cm;

preferably, a first arched tower plate (102) above the gas distributor (104) is 3-5 m away from the gas distributor (104), and the distance between adjacent arched tower plates (102) is 80 cm-150 cm.

7. The oxidation apparatus according to claim 1 or 4, wherein the chord length of the arcuate tray (102) is 20% -90% of the diameter of the column body, and the area of the arcuate tray (102) is more than half of the cross-sectional area of the oxidation column (101).

8. The oxidation device according to claim 1 or 4, wherein the holes on the arched tower plate (102) are circular or tongue-shaped, the size of the circular holes is 1 mm-30 mm, and the aperture ratio is 0.1% -10%; the aperture ratio of the tongue-shaped hole is 0.1% -10%.

9. The oxidizing device according to claim 1 or 4, wherein the oxidizing device is provided with a pre-reactor (301), a liquid inlet B (311) is arranged at the upper part of the side surface of the pre-reactor (301), a gas outlet B (314) is arranged at the top, a gas inlet B (313) is arranged at the bottom, a liquid outlet B (312) is arranged at the lower part of the side surface, gas from the oxidizing tower (101) enters from the bottom of the pre-reactor (301) and reacts with working fluid, and the reacted gas enters an oxidizing tail gas condenser; preferably 10-100% of the gas exiting the oxidation column (101) enters the pre-reactor (301).

10. The oxidizing apparatus of claim 9, wherein the pre-reactor (301) body is a rectangular parallelepiped, the left and right sides are arc surfaces, the liquid inlet B (311) and the liquid outlet B (312) are on the arc surfaces, and the length of the rectangular parallelepiped is 3 times or more the width.