Device for separating organic matters in waste acid

Abstract

The utility model discloses a device for separating organic matters in waste acid, which comprises a purification tower, and a packing layer filled with benzene is arranged in the purification tower; an outlet of the head tank is communicated with an inlet in the bottom end of the purification tower; benzene in the elevated tank is continuously conveyed into the purification tower from the bottom end of the purification tower, waste acid is conveyed into the purification tower from the top of the purification tower, the waste acid is dispersed through the filler layer and flows downwards, and the benzene and the waste acid form countercurrent for extraction so as to remove organic matters. According to the device disclosed by the utility model, kettle type stirring extraction in a traditional process is replaced by a counter-current extraction mode, and a large amount of nitrides can be recovered by combining the waste acid separator and the waste acid re-separator, so that the energy consumption cost of re-concentration treatment of the extracted waste acid is low, the safety is high, and the environmental pollution is reduced; and compared with a mechanical stirring mode, electric power resources can be saved, and the electric power cost is greatly reduced.

Description

Technical Field

[0001] This utility model belongs to the field of waste acid separation technology, and in particular relates to a device for separating organic matter from waste acid. Background Technology

[0002] Mixed dinitrobenzene is mainly used for hydrogenation to produce phenylenediamine, which is a widely used intermediate in the new materials industry and organic chemical industry. The current production process of mixed dinitrobenzene mainly includes several key steps: primary nitration, secondary nitration, neutralization, and washing. The waste acid generated from the secondary nitration is used in the primary nitration. The waste acid (also known as 72 acid) with a mass concentration of 70-75% after the primary nitration still contains 0.6%-0.8% nitrates.

[0003] Currently, the recovery and treatment of nitrates in waste acid often employs traditional batch extraction. Benzene and waste acid are continuously pumped into the extraction vessel in a specific ratio using a benzene shielded pump and a waste acid transfer pump. The agitator on the extraction vessel is then activated to mix the nitrates. The extracted mixture of nitrates and benzene flows through an overflow pipe at the top of the vessel into an acid-benzene separator for recycling in an acidic benzene tank. The extracted waste acid is then concentrated. After batch extraction with stirring and mixing, the nitrate content in the waste acid decreases from 0.6-0.8% before extraction to 0.3%-0.5% after extraction. However, during waste acid concentration, only a portion of the nitrates are eliminated, while the vast majority of nitrates and nitrogen oxides are carried into the alkaline water of the tail gas absorption tower, causing the nitrate concentration in the alkaline water to exceed the standard and creating a pollution source. Utility Model Content

[0004] This utility model addresses the problems in the prior art by proposing the following technical solution:

[0005] This utility model provides a device for separating organic matter from waste acid, including:

[0006] A purification tower, wherein the interior of the purification tower is filled with a packing layer filled with benzene;

[0007] An elevated tank, the outlet of which is connected to the bottom inlet of the purification tower;

[0008] Benzene in the high-level tank is continuously transported from the bottom of the purification tower to the purification tower, while waste acid is transported from the top of the purification tower to the interior of the purification tower. The waste acid is dispersed through the packing layer and flows downward. Benzene and waste acid form a countercurrent to extract the organic matter.

[0009] As a preferred embodiment of the above technical solution, it further includes a waste acid separator and a waste acid re-separator, wherein the waste acid separator is connected to the bottom outlet of the purification tower, and the waste acid re-separator is connected to the outlet of the waste acid separator.

[0010] As a preferred embodiment of the above technical solution, an acid-benzene separator is also included, which is connected to the top outlet of the purification tower.

[0011] As a preferred embodiment of the above technical solution, it further includes a waste acid intermediate tank, which is connected to the outlet of the waste acid re-separator.

[0012] The beneficial effects of this utility model are as follows:

[0013] This invention replaces the traditional kettle-type stirred extraction process with a countercurrent extraction method, and combines a waste acid separator and a waste acid re-separator to recover a large amount of nitrates. The energy consumption cost of the re-concentration treatment of the extracted waste acid is low, the safety is high, and environmental pollution is reduced. Moreover, compared with mechanical stirring, it can save electricity resources and significantly reduce electricity costs. Attached Figure Description

[0014] Figure 1 The diagram shown is a schematic representation of the separation device in the embodiment;

[0015] Attached reference numerals: 10, purification tower; 11, packing layer; 12, high-level tank; 13, acid-benzene separator; 14, waste acid separator; 15, waste acid re-separator; 16, intermediate tank. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments.

[0017] Example

[0018] like Figure 1 As shown, Figure 1 The diagram shown is a structural schematic of the separation device in the embodiment.

[0019] This device includes:

[0020] Purification tower 10, the interior of which is filled with a packing layer 11 filled with benzene;

[0021] The outlet of the high-level tank 12 is connected to the bottom inlet of the purification tower 10;

[0022] Benzene in the high-level tank 12 is continuously transported from the bottom of the purification tower 10 to the purification tower 10. Waste acid is transported from the top of the purification tower 10 to the interior of the purification tower 10. The waste acid is dispersed through the packing layer 11 and flows downward. Benzene and waste acid form a countercurrent to extract the nitrates.

[0023] It also includes a waste acid separator 14 and a waste acid re-separator 15. The waste acid separator 14 is connected to the bottom outlet of the purification tower 10, and the waste acid re-separator 15 is connected to the outlet of the waste acid separator 14.

[0024] Waste acid with a mass concentration of 70-75% after nitration enters the purification tower 10 from the top of the tower. The waste acid is dispersed through the packing layer 11 and flows downward. Benzene is continuously transported from the high-level tank 12 to the bottom of the purification tower 10 by means of the height difference and enters the interior of the purification tower 10 from the bottom inlet. The waste acid and benzene form a countercurrent to extract the nitrate in the waste acid.

[0025] In this process, benzene is the continuous phase and waste acid is the dispersed phase. The purified waste acid flows out of the purification tower 10 through the outlet of the end section of the purification tower 10 to the waste acid separator 14 and the waste acid re-separator 15, thereby further removing any small amount of nitrates that may be entrained. When the organic matter content is less than 1%, it is then concentrated to avoid excessive nitrates and nitrogen oxides being carried into the alkaline water of the tail gas absorption tower, which would cause the nitrate concentration in the alkaline water to exceed the standard and become a source of pollution.

[0026] By replacing the traditional stirred extraction process with countercurrent extraction, and combining it with waste acid separator 14 and waste acid re-separator 15, a large amount of nitrates can be recovered. The energy consumption cost of the waste acid re-concentration treatment after extraction is low, the safety is high, and environmental pollution is reduced. Moreover, compared with mechanical stirring, it can save electricity resources and significantly reduce electricity costs.

[0027] like Figure 1 As shown, Figure 1 The diagram shown is a structural schematic of the separation device in the embodiment.

[0028] It also includes an acid-benzene separator 13, which is connected to the top outlet of the purification tower 10.

[0029] The acidic benzene flowing out from the top outlet of the purification tower 10 flows into the acid-benzene separator 13. Further, the acidic benzene flowing into the acid-benzene separator 13 is separated and then flows into the acid-benzene cooler, and finally enters the acidic benzene tank as the raw material for the first stage of nitration reaction.

[0030] It also includes a waste acid intermediate tank 16, which is connected to the outlet of the waste acid re-separator 15.

[0031] Waste acid, after further separation in the waste acid re-separator 15, flows into the waste acid intermediate tank 16.

[0032] Working principle: In this device, waste acid with a mass concentration of 70-75% after nitration enters the purification tower 10 from the top of the tower. The waste acid is dispersed through the packing layer 11 and flows downward. Benzene is continuously transported from the high-level tank 12 to the bottom of the purification tower 10 by means of the height difference, and enters the interior of the purification tower 10 from the bottom inlet. The waste acid and benzene form a countercurrent to extract the nitrate in the waste acid.

[0033] After purification, the waste acid flows out of the purification tower 10 through the outlet of the end section of the purification tower 10 to the waste acid separator 14 and the waste acid re-separator 15, thereby further removing any small amount of nitrate that may be entrained. When the organic matter content is less than 1%, it is then concentrated to avoid excessive nitrate and nitrogen oxides being carried into the alkaline water of the tail gas absorption tower, which would cause the nitrate concentration in the alkaline water to exceed the standard and become a source of pollution.

[0034] The above embodiments are only used to illustrate the technical solution of this utility model, and are not intended to limit it.

Claims

1. A device for separating organic matter from waste acid, characterized in that, include: Purification tower (10), wherein the interior of the purification tower (10) is provided with a packing layer (11) filled with benzene; A high-level tank (12) is provided, the outlet of which is connected to the bottom inlet of the purification tower (10). The benzene in the high-level tank (12) is continuously transported from the bottom of the purification tower (10) to the purification tower (10), and the waste acid is transported from the top of the purification tower (10) to the interior of the purification tower (10). The waste acid is dispersed through the packing layer (11) and flows downward. The benzene and the waste acid form a countercurrent to extract the organic matter.

2. The organic matter separation device in waste acid according to claim 1, characterized in that, It also includes a waste acid separator (14) and a waste acid re-separator (15), wherein the waste acid separator (14) is connected to the bottom outlet of the purification tower (10), and the waste acid re-separator (15) is connected to the outlet of the waste acid separator (14).

3. The organic matter separation device in waste acid according to claim 2, characterized in that, It also includes an acid-benzene separator (13), which is connected to the top outlet of the purification tower (10).

4. The organic matter separation device in waste acid according to claim 3, characterized in that, It also includes a waste acid intermediate tank (16), which is connected to the outlet of the waste acid re-separator (15).

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