Oxidation tower equipment for low-pressure air countercurrent oxidation in industrial hydrogen peroxide production

Abstract

The utility model is applicable to the technical field of hydrogen peroxide production, and provides low-pressure air countercurrent oxidation tower equipment for industrial hydrogen peroxide production, which comprises a tank body, and the bottom end of the outer surface of the tank body is transversely communicated with an air inlet pipe. According to the low-pressure air countercurrent oxidation tower equipment for industrial hydrogen peroxide production, the tank body and the baffle plates are arranged, so that the structural design of the oxidation tower is more reasonable, the separation of an upper tower and a lower tower of the oxidation tower is canceled, the size of the oxidation tower is reduced, the equipment pipeline investment of an oxidation system is reduced, and a low-pressure countercurrent oxidation technology is adopted; the device is suitable for modification of old devices, materials at the last reaction stage are dissociated from fresh air through countercurrent oxidation, oxidation is more complete, meanwhile, the air at the last reaction stage is in contact reaction with fresh working liquid through countercurrent oxidation reaction, the utilization rate of oxygen in the air is further increased, the cleanliness of the oxidation tower is improved, and the service life of the oxidation tower is prolonged. And the safety of the device is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydrogen peroxide production, in particular to an oxidation tower device for low-pressure air countercurrent oxidation in industrial hydrogen peroxide production. Background Art

[0002] The anthraquinone process for producing hydrogen peroxide (commonly known as hydrogen peroxide, hereinafter referred to as hydrogen peroxide) uses 2-ethylanthraquinone and tetrahydroanthraquinone as working carriers, a mixed solvent of heavy aromatic hydrocarbons and trioctyl phosphate, tetrabutyl urea, or acetate, and employs a palladium-catalyzed fixed-bed hydrogenation process, followed by air oxidation in an oxidation tower and extraction purification. Traditional oxidation towers consist of two towers (some have three sections: upper, middle, and lower). The working fluid and air enter the upper and lower towers simultaneously. After a mixed reaction in the upper tower, they enter the upper tower's gas-liquid separator. The gaseous phase ascends to the upper tower and enters the tail gas condenser. The liquid phase passes through the oxidation liquid heat exchanger and enters the lower tower, where it mixes with the air in the lower tower and undergoes further oxidation. The resulting gas-liquid mixture enters the lower tower's gas-liquid separator from the top of the lower tower. After controlling the liquid level, it enters the oxidation liquid storage tank. After being pressurized by the oxidation liquid pump, it enters the extraction purification process.

[0003] The oxidation process is one of the key steps in the production of hydrogen peroxide, and the oxidation tower is one of the key equipment. The oxidation tower oxidizes 2-ethylanthraquinone (EAQ) and tetrahydro-2-ethylanthraquinone (H4EAQ) to produce hydrogen peroxide and tetrahydro-2-ethylanthraquinone or 2-ethylanthraquinone. The reaction formula is: HEAQ + O2 → EAQ + H2O2 or H4EAQ + O2 → HEAQ + H2O2;

[0004] The oxidation tower equipment of the original traditional oxidation process has the following problems due to unreasonable structural design: liquid in tail gas, low air utilization, complex process pipelines and low oxidation yield, etc., which means there is a large room for energy saving and consumption reduction. Utility Model Content

[0005] The utility model provides an oxidation tower device for low-pressure air countercurrent oxidation in the production of industrial hydrogen peroxide, aiming to solve the problems of the oxidation tower equipment in the original traditional oxidation process, such as liquid carried in tail gas, low air utilization, complex process pipelines and low oxidation yield, and the problem that there is a large space for energy saving and consumption reduction.

[0006] The utility model is achieved by providing an oxidation tower device for low-pressure air countercurrent oxidation in the production of industrial hydrogen peroxide, comprising a tank body, the bottom end of the outer surface of the tank body being laterally connected to an air inlet pipe, the inner bottom end of the tank body being fixedly connected to an air distributor in communication with the inner end of the air inlet pipe, the upper end of the outer surface of the tank body being laterally connected to a hydrogenated liquid inlet pipe, the upper end of the inner part of the tank body being fixedly connected to a hydrogenated liquid distributor in communication with the inner end of the hydrogenated liquid inlet pipe;

[0007] A plurality of semi-annular baffles are laterally fixedly connected inside the tank body and between the air distributor and the hydrogenated liquid distributor. The plurality of baffles are evenly spaced along the length direction of the tank body and every two adjacent baffles are fixedly connected to both sides of the inner surface of the tank body, respectively. The upper surfaces of the plurality of baffles are vertically penetrated with a plurality of distribution holes.

[0008] Preferably, a wire mesh demister is fixedly connected transversely to the top end of the interior of the tank body.

[0009] Preferably, the top of the tank body is connected to a nitrogen protection pipe, an exhaust gas outlet pipe, and a tower top pressure display pipe.

[0010] Preferably, a plurality of built-in coolers are transversely fixedly connected to the interior of the tank body.

[0011] Preferably, a remote thermometer port is provided on the outer surface of the tank body and below the built-in cooler.

[0012] Preferably, the bottom end of the tank body is connected to an oxidation liquid discharge pipe, and an anti-vortex plate is fixedly connected to the bottom end of the tank body and the top end of the oxidation liquid discharge pipe.

[0013] Preferably, the outer surface of the tank body is provided with a first double-flange differential pressure transmitter and a second double-flange differential pressure transmitter, the upper portion of the outer surface of the tank body is fixedly connected to a tower top field level gauge, the outer surface of the tank body is fixedly connected to a ladder along its length direction, and the bottom end of the outer surface of the tank body is fixedly connected to a plurality of support legs.

[0014] Beneficial effects

[0015] Compared with the prior art, the beneficial effects of the utility model are as follows: the utility model is an oxidation tower device for low-pressure air countercurrent oxidation in the production of industrial hydrogen peroxide. By arranging a tank body and multiple baffles, the oxidation tower structure is more reasonably designed. At the same time, the distinction between the upper and lower towers of the oxidation tower is eliminated, the volume of the oxidation tower is reduced, thereby reducing the equipment and pipeline investment of the oxidation system. The utility model adopts low-pressure countercurrent oxidation technology, which is suitable for the transformation of old equipment. The countercurrent oxidation is used to connect the material at the end of the reaction with fresh air to make it oxidized more completely. At the same time, the countercurrent oxidation reaction allows the air at the end of the reaction to contact and react with the fresh working fluid, so that the oxygen utilization rate in the air is further improved, the oxygen content of the oxidation tail gas is effectively reduced, and the oxidation yield is improved, thereby further reducing the power consumption of the air compressor. At the same time, the countercurrent oxidation reaction process eliminates the residual hydrogen peroxide in the oxidation, improves the cleanliness of the oxidation tower, and thus improves the safety of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the cross-sectional structure of the utility model;

[0017] Figure 2 This is a schematic diagram of the overall external structure of the utility model;

[0018] Figure 3 It is a structural schematic diagram of the baffle in the utility model.

[0019] In the figure: 1-tank body, 2-air inlet pipe, 3-air distributor, 4-hydrogenated liquid inlet pipe, 5-hydrogenated liquid distributor, 6-baffle, 7-distribution hole, 8-built-in cooler, 9-wire mesh demister, 10-nitrogen protection pipe, 11-tail gas outlet pipe, 12-tower top pressure display tube, 13-remote thermometer port, 14-anti-vortex plate, 15-oxidation liquid discharge pipe, 16-ladder, 17-first double-flange differential pressure transmitter, 18-second double-flange differential pressure transmitter, 19-tower top field level gauge, 20-support leg. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0021] See also Figure 1-3 The utility model provides a technical solution: an oxidation tower device for low-pressure air countercurrent oxidation in the production of industrial hydrogen peroxide, comprising a tank body 1, the bottom end of the outer surface of the tank body 1 being horizontally connected to an air inlet pipe 2, the bottom end of the interior of the tank body 1 being fixedly connected to an air distributor 3 communicating with the inner end of the air inlet pipe 2, the upper end of the outer surface of the tank body 1 being horizontally connected to a hydrogenation liquid inlet pipe 4, the upper end of the interior of the tank body 1 being fixedly connected to a hydrogenation liquid distributor 5 communicating with the inner end of the hydrogenation liquid inlet pipe 4;

[0022] A plurality of semi-annular baffles 6 are fixedly connected laterally inside the tank body 1 and between the air distributor 3 and the hydrogenated liquid distributor 5. The plurality of baffles 6 are evenly spaced along the length direction of the tank body 1 and every two adjacent baffles 6 are fixedly connected to both sides of the inner surface of the tank body 1. The upper surfaces of the plurality of baffles 6 are vertically penetrated with a plurality of distribution holes 7.

[0023] In this embodiment, when the device is in operation, air enters the air distributor 3 through the air inlet pipe 2 and then enters the interior of the tank body 1, while the hydrogenated liquid enters the hydrogenated liquid distributor 5 through the hydrogenated liquid inlet pipe 4 and then enters the interior of the tank body 1. Thereafter, the air flows above the tank body 1, while the hydrogenated liquid flows to the bottom of the tank body 1. During this process, the two will move along an S-shaped route under the action of multiple baffles 6, which can ensure sufficient reaction between the two and ultimately produce hydrogen peroxide.

[0024] The nozzles in the air distributor 3 of the device are designed to be spread over the entire tower cross-section, with the opening of each nozzle located at one-third of the upper surface so that the ejected air flows vertically upward; they cannot be opened on the sides or bottom, otherwise the ejected air will bend and change direction, affecting the reaction effect.

[0025] At the same time, the hydrogenation liquid distributor 5 adopts a "cross" distribution form, and the distributor discharge port faces downward. Because it is a single-side feed, the discharge port close to the feed pipe mouth should be smaller to avoid short circuit of the material.

[0026] Furthermore, a wire mesh demister 9 is fixedly connected transversely to the top of the interior of the tank body 1 .

[0027] The top of the tank body 1 is connected to a nitrogen protection pipe 10 , an exhaust gas outlet pipe 11 , and a tower top pressure display pipe 12 .

[0028] The bottom end of the tank body 1 is connected to an oxidation liquid discharge pipe 15 , and an anti-vortex plate 14 is fixedly connected to the bottom end of the tank body 1 and the top end of the oxidation liquid discharge pipe 15 .

[0029] In this embodiment, the hydrogenated liquid enters the tank body 1 and flows downward. The hydrogenated liquid reacts with air to generate an oxidizing liquid and hydrogen peroxide. As the concentration of hydrogen peroxide in the oxidizing liquid increases, the concentration of hydrogen peroxide increases as it flows downward, forming a gravity difference between the upper and lower components. Due to axial molecular diffusion and turbulent diffusion and natural convection caused by the gravity difference between the upper and lower components, axial reverse mixing is inevitable. That is, the hydrogenated liquid entering the tower mixes with the oxidizing liquid that has generated the product hydrogen peroxide. This mixing is not conducive to the reaction. The oxidizing liquid discharge pipe 15 provided at the bottom end of the tank body 1 can just solve this problem.

[0030] The oxidation reaction in the tank body 1 is a heterogeneous reaction, and its reaction rate is controlled by the interphase material transfer rate. In order to strengthen this process, the interphase area and diffusion rate must be increased to increase the material flow rate in the tower, so that it is in turbulence and produces irregular vortex motion, which is the best means to achieve heterogeneous reaction. The baffle 6 with dispersion holes can just solve this problem, increase the flow rate of the gas-liquid mixture in the tower, make the logistics in a turbulent and cross-flow state, destroy the opportunity of air to form large bubbles and short-circuit, and achieve the purpose of secondary full mixing of gas and liquid.

[0031] The gas generated after the reaction is completed will be discharged through the tail gas outlet pipe 11 at the top of the tank body 1. The nitrogen protection tube 10 can use nitrogen to simulate air for system circulation in the initial operation of the device, which can reduce the operating time of the air compressor and thus reduce power consumption. The tower top pressure display tube 12 can display the internal pressure of the tank body 1.

[0032] Furthermore, a plurality of built-in coolers 8 are transversely fixedly connected to the interior of the tank body 1 .

[0033] The feature of the invention is that a remote thermometer port 13 is provided on the outer surface of the tank body 1 and below the built-in cooler 8 .

[0034] In this embodiment, the built-in cooler 8 is a multi-group plug-in type, with only a hole opened on the side of the tank body 1, and is designed to cover the entire cross-section of the tank body 1. The water inlet main pipe and the remote thermometer port 13 must be located below the built-in cooler 8 to form an automatic linkage control to achieve a mild oxidation reaction and reduce the production of by-products.

[0035] Furthermore, the outer surface of the tank body 1 is provided with a first double-flange differential pressure transmitter 17 and a second double-flange differential pressure transmitter 18, the upper part of the outer surface of the tank body 1 is fixedly connected to a tower top field liquid level meter 19, the outer surface of the tank body 1 is fixedly connected to a ladder 16 along its length direction, and the bottom end of the outer surface of the tank body 1 is fixedly connected to a plurality of support legs 20.

[0036] In this embodiment, the first double-flange differential pressure transmitter 17 and the second double-flange differential pressure transmitter 18 can be used to calculate the volume of the working fluid when the equipment is stopped, and can also be used to estimate the system feed liquid during production operation as a reference for process operation to avoid affecting the oxidation reaction time when the liquid in the tower is too low, thereby affecting the oxidation yield.

[0037] The on-site liquid level meter 19 at the top of the tower can detect the liquid level inside the tank body 1 when the equipment is running.

[0038] The ladder 16 is for use by workers, who can climb up the tank body 1 via the ladder 16 to perform maintenance or inspection on the device, and the plurality of support legs 20 provide support.

[0039] The working principle and use process of the utility model: After the utility model is installed, when the device is in operation, air enters the air distributor 3 through the air inlet pipe 2 and then enters the interior of the tank body 1, while the hydrogenated liquid enters the hydrogenated liquid distributor 5 through the hydrogenated liquid inlet pipe 4 and then enters the interior of the tank body 1. After that, the air flows above the tank body 1, and the hydrogenated liquid flows to the bottom of the tank body 1. In this process, the two will move along an S-shaped route under the action of multiple baffles 6, which can ensure that there is a full reaction between the two, and finally hydrogen peroxide and hydrogen are produced. As the hydrogenated liquid enters the tank 1 and flows downward, the hydrogenated liquid reacts with air to form an oxidizing liquid and hydrogen peroxide. As the concentration of hydrogen peroxide in the oxidizing liquid increases, the concentration of hydrogen peroxide increases the further it goes downward, forming a density difference between the upper and lower components. Due to axial molecular diffusion and turbulent diffusion, as well as natural convection caused by the density difference between the upper and lower components, axial reverse mixing is inevitable. That is, the hydrogenated liquid entering the tower mixes with the oxidizing liquid that has already generated the product hydrogen peroxide. This mixing is not conducive to the reaction. The oxidizing liquid discharge pipe 15 provided at the bottom end of the tank 1 can just solve this problem.

[0040] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An oxidation tower device for low-pressure air countercurrent oxidation in the production of industrial hydrogen peroxide, characterized in that: The invention comprises a tank body (1), wherein the bottom end of the outer surface of the tank body (1) is transversely connected to an air inlet pipe (2), the bottom end of the interior of the tank body (1) is fixedly connected to an air distributor (3) that is in communication with the inner end of the air inlet pipe (2), the upper end of the outer surface of the tank body (1) is transversely connected to a hydrogenated liquid inlet pipe (4), and the upper end of the interior of the tank body (1) is fixedly connected to a hydrogenated liquid distributor (5) that is in communication with the inner end of the hydrogenated liquid inlet pipe (4); A plurality of semi-annular baffles (6) are transversely fixedly connected inside the tank body (1) and between the air distributor (3) and the hydrogenated liquid distributor (5). The plurality of baffles (6) are evenly spaced along the length direction of the tank body (1) and every two adjacent baffles (6) are respectively fixedly connected to both sides of the inner surface of the tank body (1). The upper surfaces of the plurality of baffles (6) are vertically penetrated with a plurality of distribution holes (7).

2. A kind of oxidation tower equipment for low-pressure air countercurrent oxidation in industrial hydrogen peroxide production as claimed in claim 1, characterized in that: A wire mesh demister (9) is fixedly connected transversely to the top end of the interior of the tank body (1).

3. A kind of oxidation tower equipment for industrial hydrogen peroxide production low-pressure air countercurrent oxidation as claimed in claim 1, characterized in that: The top of the tank body (1) is connected to a nitrogen protection pipe (10), an exhaust gas outlet pipe (11), and a tower top pressure display pipe (12).

4. A kind of oxidation tower equipment for low-pressure air countercurrent oxidation in industrial hydrogen peroxide production as claimed in claim 1, characterized in that: A plurality of built-in coolers (8) are transversely fixedly connected to the interior of the tank body (1).

5. A kind of oxidation tower equipment for low-pressure air countercurrent oxidation in industrial hydrogen peroxide production as claimed in claim 4, characterized in that: A remote thermometer port (13) is provided on the outer surface of the tank body (1) and below the built-in cooler (8).

6. A kind of oxidation tower equipment for low-pressure air countercurrent oxidation in industrial hydrogen peroxide production as claimed in claim 1, characterized in that: The bottom end of the tank body (1) is connected to an oxidation liquid discharge pipe (15), and an anti-vortex plate (14) is fixedly connected to the bottom end inside the tank body (1) and located at the top end of the oxidation liquid discharge pipe (15).

7. A kind of oxidation tower equipment for low-pressure air countercurrent oxidation in industrial hydrogen peroxide production as claimed in claim 1, characterized in that: The outer surface of the tank body (1) is provided with a first double-flange differential pressure transmitter (17) and a second double-flange differential pressure transmitter (18); the upper portion of the outer surface of the tank body (1) is fixedly connected to a tower top field level meter (19); the outer surface of the tank body (1) is fixedly connected to a ladder (16) along its length; and the bottom end of the outer surface of the tank body (1) is fixedly connected to a plurality of support legs (20).

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