Novel ethylene carbonate tail gas treatment device

Abstract

The utility model relates to a novel ethylene carbonate tail gas treatment device. According to the technical scheme, a lower side inlet of a tail gas washing tower is connected to an ethylene oxide tail gas inlet end through an ethylene oxide tail gas pipe; a multi-stage spray header is arranged at the upper part of an inner cavity of the tail gas washing tower and is connected to a process water inlet end through a process pipeline, and the top of the tail gas washing tower is connected to an inner cavity of the tail gas discharge buffer tank through a pipeline; the bottom of the tail gas washing tower is connected to a waste liquid buffer tank through a pipeline, a first washing tower circulating pump and a second washing tower circulating pump, a first circulating pump controller is mounted on the first washing tower circulating pump, and a second circulating pump controller is mounted on the second washing tower circulating pump; the bottom of the tail gas discharge buffer tank is connected to the lower side line of the tail gas washing tower through a pipeline. The ethylene oxide tail gas treatment device has the beneficial effects that ethylene oxide tail gas is treated through the tail gas washing tower, and sewage is controlled to be directly discharged or circulated for tail gas treatment according to the concentration of washing water, so that process water resources are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of ethylene oxide tail gas treatment, in particular to a novel ethylene carbonate tail gas treatment device. Background Art

[0002] Ethylene carbonate (EC) is an organic chemical raw material with excellent performance and a wide range of uses. Ethylene carbonate is the main raw material for producing dimethyl carbonate by the transesterification method. In recent years, high-purity ethylene carbonate is also mainly used in lithium battery electrolytes. It is the largest solvent in lithium battery electrolytes. In the future, with the development of lithium-ion power batteries, the amount of ethylene carbonate solvent will increase, and the development prospects are broad. The commonly used preparation method is: ethylene oxide and carbon dioxide addition reaction to prepare ethylene carbonate. In the production process of ethylene carbonate, a large amount of carbon dioxide, ethylene oxide, and ethylene carbonate gas phase mixed gas will be generated. The gas needs to be condensed on site and then part of the condensate is recovered, but there is still a small amount of ethylene oxide waste gas that cannot be recovered, causing environmental pollution, and cannot be directly discharged into the atmosphere. Utility Model Content

[0003] The purpose of the utility model is to provide a novel ethylene carbonate tail gas treatment device in view of the above-mentioned defects in the prior art, which treats ethylene oxide tail gas through a tail gas washing tower, and controls the concentration of washing water to directly discharge sewage or circulate the tail gas for tail gas treatment, thereby saving process water resources and reducing pollution to the environment.

[0004] The utility model discloses a novel ethylene carbonate tail gas treatment device, and the technical scheme thereof is as follows: comprising an ethylene oxide tail gas inlet end (1), an ethylene carbonate inlet end (2), an ethylene carbonate homogeneous device end (3), an ethylene carbonate heterogeneous device end (4), a tail gas washing tower (8), a multi-stage spray head (9), a tail gas discharge buffer tank (10), a first washing tower circulation pump (11), a second washing tower circulation pump (12), a first circulation pump controller (13), a second circulation pump controller (14), a waste liquid buffer tank (15), and a process water inlet end (16); the lower inlet of the tail gas washing tower (8) is connected to the ethylene carbonate inlet end (2), the ethylene carbonate homogeneous device end (3), and the ethylene carbonate heterogeneous device end (4) through an ethylene carbonate collecting pipe (21); the tail gas washing tower (8) The lower inlet is connected to the ethylene oxide tail gas inlet end (1) through an ethylene oxide tail gas pipe (22); a multi-stage spray head (9) is provided at the upper part of the inner cavity of the tail gas washing tower (8), and the multi-stage spray head (9) is connected to the process water inlet end (16) through a process pipeline (23); the top of the tail gas washing tower (8) is connected to the inner cavity of the tail gas discharge buffer tank (10) through a pipeline; the bottom of the tail gas washing tower (8) is connected to the waste liquid buffer tank (15) through a pipeline, a first washing tower circulation pump (11) and a second washing tower circulation pump (12); a first circulation pump controller (13) is installed on the first washing tower circulation pump (11), and a second circulation pump controller (14) is installed on the second washing tower circulation pump (12); the bottom of the tail gas discharge buffer tank (10) is connected to the lower line of the tail gas washing tower (8) through a pipeline.

[0005] Preferably, a first interlocking start pump (5) is installed on the ethylene oxide tail gas pipe (22), a second interlocking start pump (6) is installed on the ethylene carbonate collecting pipe (21), a liquid level gauge (7) is provided on the lower side of the tail gas washing tower (8), a process water control valve (17) is installed on the process pipeline (23), the liquid level gauge (7) is connected to the process water control valve (17) via a signal line, and the first interlocking start pump (5) and the second interlocking start pump (6) are connected to the first circulation pump controller (13) and the second circulation pump controller (14) via signal lines.

[0006] Preferably, a sewage control valve (18) is installed on the pipeline connected to the waste liquid buffer tank (15), and the sewage control valve (18) is connected to the signal line on the liquid level meter (7) via a signal line.

[0007] Preferably, a buffer tank level gauge (10.1) is provided on one side of the exhaust gas discharge buffer tank (10), and an exhaust pipe (10.2) is provided on the top of the exhaust gas discharge buffer tank (10).

[0008] Preferably, a first concentration meter (19) is installed at the output end of the first washing tower circulation pump (11), and a second concentration meter (20) is installed at the output end of the second washing tower circulation pump (12).

[0009] Preferably, the bottom of the tail gas scrubber (8) is connected to a main line (a1), a first scrubber circulating pump (11) is installed on the main line (a1), a secondary line (a2) is connected in parallel to the main line (a1), a second scrubber circulating pump (12) is installed on the secondary line (a2), and the output end of the second scrubber circulating pump (12) is connected to the main line (a1) outside the output end of the first scrubber circulating pump (11) through the secondary line (a2).

[0010] Preferably, a first gate valve (b1) is installed at the output end of the first washing tower circulation pump (11), and a second gate valve (b2) is installed at the output end of the second washing tower circulation pump (12), and the end of the main pipeline (a1) is connected to the third sub-pipeline (a3) ​​and the fourth sub-pipeline (a4) through a tee, and a third gate valve (b3) is installed on the third sub-pipeline (a3), and a fourth gate valve (b4) is installed on the fourth sub-pipeline (a4).

[0011] Preferably, the end of the ethylene oxide tail gas pipe (22) is inserted into the bottom of the inner cavity of the tail gas scrubbing tower (8) and is located below the liquid level of the process water.

[0012] The beneficial effects of the utility model are as follows: by sending the ethylene oxide tail gas to the bottom of the inner cavity of the tail gas washing tower, preliminary treatment is achieved, and the ethylene carbonate solvent is respectively collected and sent to the lower part of the inner cavity of the tail gas washing tower. In the process of the ethylene oxide tail gas rising in the inner cavity of the tail gas washing tower, one way is to control the process water along the multi-stage spray head and the filler in the tower to achieve the treatment of the ethylene oxide tail gas, and the other way is to control the ethylene carbonate solvent to be sent to the multi-stage spray head to dissolve the ethylene oxide tail gas until the clean gas is sent along the top to the tail gas discharge buffer tank. The treated gas meets the comprehensive emission standards for atmospheric pollutants and can be directly discharged to the atmosphere to avoid environmental pollution and save process water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of embodiment 1 of the utility model;

[0014] Figure 2 It is a structural schematic diagram of embodiment 2 of the utility model;

[0015] In the figure above: ethylene oxide tail gas inlet end 1, ethylene carbonate inlet end 2, ethylene carbonate homogeneous device end 3, ethylene carbonate heterogeneous device end 4, first interlock start pump 5, second interlock start pump 6, liquid level meter 7, tail gas washing tower 8, multi-stage spray head 9, tail gas discharge buffer tank 10, first washing tower circulation pump 11, second washing tower circulation pump 12, first circulation pump controller 13, second circulation pump controller 14, waste liquid buffer tank 15, process water inlet end 16, process water control valve 17, sewage control valve 18, first concentration meter 19, second concentration meter 20, ethylene carbonate collection pipe 21, ethylene oxide tail gas pipe 22, process pipeline 23, tower pump 8.1, buffer tank liquid level meter 10.1, exhaust pipe 10.2, main pipeline a1, sub-pipeline a2, third sub-pipeline a3, fourth sub-pipeline a4, first gate valve b1, second gate valve b2, third gate valve b3, fourth gate valve b4. DETAILED DESCRIPTION

[0016] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0017] Example 1, reference Figure 1 The utility model mentions a novel ethylene carbonate tail gas treatment device, comprising an ethylene oxide tail gas inlet end 1, an ethylene carbonate inlet end 2, an ethylene carbonate homogeneous device end 3, an ethylene carbonate heterogeneous device end 4, a tail gas washing tower 8, a multi-stage spray head 9, a tail gas discharge buffer tank 10, a first washing tower circulation pump 11, a second washing tower circulation pump 12, a first circulation pump controller 13, a second circulation pump controller 14, a waste liquid buffer tank 15, and a process water inlet end 16. The lower inlet of the tail gas washing tower 8 is connected to the ethylene carbonate inlet end 2, the ethylene carbonate homogeneous device end 3 and the ethylene carbonate heterogeneous device end 4 through an ethylene carbonate collecting pipe 21; the lower inlet of the tail gas washing tower 8 The outlet is connected to the ethylene oxide tail gas inlet port 1 through an ethylene oxide tail gas pipe 22; a multi-stage spray head 9 is provided on the upper part of the inner cavity of the tail gas washing tower 8, and the multi-stage spray head 9 is connected to the process water inlet port 16 through a process pipeline 23, and the top of the tail gas washing tower 8 is connected to the inner cavity of the tail gas discharge buffer tank 10 through a pipeline; the bottom of the tail gas washing tower 8 is connected to the waste liquid buffer tank 15 through a pipeline, a first washing tower circulation pump 11 and a second washing tower circulation pump 12, a first circulation pump controller 13 is installed on the first washing tower circulation pump 11, and a second circulation pump controller 14 is installed on the second washing tower circulation pump 12, and the bottom of the tail gas discharge buffer tank 10 is connected to the lower side line of the tail gas washing tower 8 through a pipeline.

[0018] In addition, it should be noted that: an internal pump 8.1 is provided at the bottom of the inner cavity of the tail gas washing tower 8, and the ethylene carbonate solution in the inner cavity of the tower can be sent to the multi-stage spray head 9 through the internal pump 8.1, so as to dissolve and absorb the ethylene oxide tail gas.

[0019] Among them, a first interlocking starting pump 5 is installed on the above-mentioned ethylene oxide tail gas pipe 22, and a second interlocking starting pump 6 is installed on the ethylene carbonate collecting pipe 21. A liquid level meter 7 is provided on the lower side of the tail gas washing tower 8. A process water control valve 17 is installed on the process pipeline 23. The liquid level meter 7 is connected to the process water control valve 17 through a signal line. The first interlocking starting pump 5 and the second interlocking starting pump 6 are connected to the first circulation pump controller 13 and the second circulation pump controller 14 through a signal line. The amount of ethylene oxide tail gas and ethylene carbonate entering, as well as the amount of process water entering can be controlled according to the liquid level.

[0020] A sewage control valve 18 is installed on the pipeline connected to the waste liquid buffer tank 15 , and the sewage control valve 18 is connected to a signal line on the liquid level meter 7 through a signal line.

[0021] A buffer tank level gauge 10.1 is provided on one side of the exhaust gas discharge buffer tank 10, and an exhaust pipe 10.2 is provided on the top of the exhaust gas discharge buffer tank 10.

[0022] A first concentration meter 19 is installed at the output end of the first washing tower circulation pump 11 , and a second concentration meter 20 is installed at the output end of the second washing tower circulation pump 12 .

[0023] In addition, a main line a1 is connected to the bottom of the tail gas washing tower 8, on which a first washing tower circulation pump 11 is installed, and a sub-line a2 is connected in parallel to the main line a1, on which a second washing tower circulation pump 12 is installed, and the output end of the second washing tower circulation pump 12 is collected to the main line a1 outside the output end of the first washing tower circulation pump 11 through the sub-line a2.

[0024] In addition, a first gate valve b1 is installed at the output end of the first washing tower circulation pump 11, and a second gate valve b2 is installed at the output end of the second washing tower circulation pump 12. The end of the main line a1 is connected to the third sub-pipeline a3 and the fourth sub-pipeline a4 through a tee, and a third gate valve b3 is installed on the third sub-pipeline a3, and a fourth gate valve b4 is installed on the fourth sub-pipeline a4.

[0025] The end of the ethylene oxide tail gas pipe 22 is inserted into the bottom of the inner cavity of the tail gas washing tower 8 and is located below the liquid level of the process water, which can achieve a better effect of treating the ethylene oxide tail gas.

[0026] When the utility model is used, the ethylene oxide tail gas is fed into the bottom of the inner cavity of the tail gas washing tower 8 to achieve preliminary treatment, and the ethylene carbonate inlet end, the ethylene carbonate homogeneous device end and the ethylene carbonate heterogeneous device end are respectively collected and fed into the lower part of the inner cavity of the tail gas washing tower 8. Then, in the process of the ethylene oxide tail gas rising in the inner cavity of the tail gas washing tower 8, one path is through process water along the multi-stage spray head 9 and the filler in the tower to achieve the treatment of the ethylene oxide tail gas, and the other path is through sending ethylene carbonate solvent to the multi-stage spray head 9 to dissolve the ethylene oxide tail gas until the clean gas is sent along the top to the tail gas discharge buffer tank 10. The treated gas meets the ethylene oxide gas discharge standard in the comprehensive emission standard for atmospheric pollutants GB16297-1996, and can be directly discharged to the atmosphere to avoid polluting the environment.

[0027] During the spray absorption process: on the one hand, the tail gas washing tower 8 itself sends the mixed solvent of ethylene carbonate and process water to the multi-stage spray head 9 for spraying and adsorbing ethylene oxide tail gas; on the other hand, it can also indirectly control the opening of the first gate valve b1 and the third gate valve b3 at the output end of the first washing tower circulation pump 11, and the closing of the second gate valve b2 and the fourth gate valve b4, so that the mixed solvent of ethylene carbonate and process water is sent to the multi-stage spray head 9 for spraying to absorb the remaining ethylene oxide in the tail gas, thereby purifying a small amount of ethylene oxide in the tail gas and saving process water resources; and when the concentration of ethylene oxide increases, the first gate valve b1 and the third gate valve b3 at the output end of the first washing tower circulation pump 11 are controlled to be closed, and the second gate valve b2 and the fourth gate valve b4 are opened, and the waste liquid is sent to the waste liquid buffer tank 15 for further treatment.

[0028] Embodiment 2, a novel ethylene carbonate tail gas treatment device mentioned in the utility model comprises an ethylene oxide tail gas inlet end 1, an ethylene carbonate inlet end 2, an ethylene carbonate homogeneous device end 3, an ethylene carbonate heterogeneous device end 4, a tail gas washing tower 8, a multi-stage spray head 9, a tail gas discharge buffer tank 10, a first washing tower circulation pump 11, a first circulation pump controller 13, a waste liquid buffer tank 15, and a process water inlet end 16, wherein the lower inlet of the tail gas washing tower 8 is connected to the ethylene carbonate inlet end 2, the ethylene carbonate homogeneous device end 3 and the ethylene carbonate heterogeneous device end 4 through an ethylene carbonate collecting pipe 21; the tail gas The lower inlet of the washing tower 8 is connected to the ethylene oxide tail gas inlet end 1 through the ethylene oxide tail gas pipe 22; a multi-stage spray head 9 is provided on the upper part of the inner cavity of the tail gas washing tower 8, and the multi-stage spray head 9 is connected to the process water inlet end 16 through the process pipeline 23, and the top of the tail gas washing tower 8 is connected to the inner cavity of the tail gas discharge buffer tank 10 through a pipeline; the bottom of the tail gas washing tower 8 is connected to the waste liquid buffer tank 15 through a pipeline and a first washing tower circulation pump 11, and a first circulation pump controller 13 is installed on the first washing tower circulation pump 11, and the bottom of the tail gas discharge buffer tank 10 is connected to the lower side line of the tail gas washing tower 8 through a pipeline.

[0029] The difference from Example 1 is:

[0030] In this embodiment, the secondary pipeline a2 and the second washing tower circulation pump 12, the second circulation pump controller 14, the second gate valve b2 and the second concentration meter 20 on the secondary pipeline a2 are removed. The above basic functions can also be achieved through the first washing tower circulation pump 11 on the main pipeline, meeting the design purpose of the utility model.

[0031] The above is only a preferred embodiment of the utility model. Any person skilled in the art may modify the utility model by using the above technical solution or modify it into an equivalent technical solution. Therefore, any simple modification or equivalent transformation based on the technical solution of the utility model shall fall within the scope of protection claimed by the utility model.

Claims

1. A novel ethylene carbonate tail gas treatment device, characterized in that: The invention comprises an ethylene oxide tail gas inlet end (1), an ethylene carbonate inlet end (2), an ethylene carbonate homogeneous device end (3), an ethylene carbonate heterogeneous device end (4), a tail gas washing tower (8), a multi-stage spray head (9), a tail gas discharge buffer tank (10), a first washing tower circulation pump (11), a second washing tower circulation pump (12), a first circulation pump controller (13), a second circulation pump controller (14), a waste liquid buffer tank (15), and a process water inlet end (16). The lower inlet of the tail gas washing tower (8) is connected to the ethylene carbonate inlet end (2), the ethylene carbonate homogeneous device end (3), and the ethylene carbonate heterogeneous device end (4) through an ethylene carbonate collecting pipe (21); the lower inlet of the tail gas washing tower (8) is connected to the ethylene carbonate inlet end (2), the ethylene carbonate homogeneous device end (3), and the ethylene carbonate heterogeneous device end (4) through an ethylene oxide tail gas pipe (22). ) is connected to the ethylene oxide tail gas inlet end (1); a multi-stage spray head (9) is provided at the upper part of the inner cavity of the tail gas washing tower (8), and the multi-stage spray head (9) is connected to the process water inlet end (16) through a process pipeline (23); the top of the tail gas washing tower (8) is connected to the inner cavity of the tail gas discharge buffer tank (10) through a pipeline; the bottom of the tail gas washing tower (8) is connected to the waste liquid buffer tank (15) through a pipeline, a first washing tower circulation pump (11) and a second washing tower circulation pump (12); a first circulation pump controller (13) is installed on the first washing tower circulation pump (11), and a second circulation pump controller (14) is installed on the second washing tower circulation pump (12); the bottom of the tail gas discharge buffer tank (10) is connected to the lower side line of the tail gas washing tower (8) through a pipeline.

2. The novel ethylene carbonate tail gas treatment device according to claim 1, characterized in that: A first interlocking start pump (5) is installed on the ethylene oxide tail gas pipe (22), a second interlocking start pump (6) is installed on the ethylene carbonate collecting pipe (21), a liquid level meter (7) is provided on the lower side of the tail gas washing tower (8), a process water control valve (17) is installed on the process pipeline (23), the liquid level meter (7) is connected to the process water control valve (17) via a signal line, and the first interlocking start pump (5) and the second interlocking start pump (6) are connected to a first circulation pump controller (13) and a second circulation pump controller (14) via signal lines.

3. The novel ethylene carbonate tail gas treatment device according to claim 2, characterized in that: A sewage control valve (18) is installed on the pipeline connected to the waste liquid buffer tank (15), and the sewage control valve (18) is connected to the signal line on the liquid level meter (7) via a signal line.

4. The novel ethylene carbonate tail gas treatment device according to claim 3, characterized in that: A buffer tank liquid level gauge (10.1) is provided on one side of the exhaust gas discharge buffer tank (10), and an exhaust pipe (10.2) is provided on the top of the exhaust gas discharge buffer tank (10).

5. The novel ethylene carbonate tail gas treatment device according to claim 3 or 4, characterized in that: A first concentration meter (19) is installed at the output end of the first washing tower circulation pump (11), and a second concentration meter (20) is installed at the output end of the second washing tower circulation pump (12).

6. The novel ethylene carbonate tail gas treatment device according to claim 5 is characterized in that: The bottom of the tail gas scrubber (8) is connected to a main line (a1), a first scrubber circulating pump (11) is installed on the main line (a1), a secondary line (a2) is connected in parallel to the main line (a1), a second scrubber circulating pump (12) is installed on the secondary line (a2), and the output end of the second scrubber circulating pump (12) is connected to the main line (a1) outside the output end of the first scrubber circulating pump (11) through the secondary line (a2).

7. The novel ethylene carbonate tail gas treatment device according to claim 6 is characterized in that: A first gate valve (b1) is installed at the output end of the first washing tower circulation pump (11), and a second gate valve (b2) is installed at the output end of the second washing tower circulation pump (12); the end of the main pipeline (a1) is connected to the third sub-pipeline (a3) ​​and the fourth sub-pipeline (a4) through a tee, and a third gate valve (b3) is installed on the third sub-pipeline (a3), and a fourth gate valve (b4) is installed on the fourth sub-pipeline (a4).

8. The novel ethylene carbonate tail gas treatment device according to claim 1 is characterized in that: The end of the ethylene oxide tail gas pipe (22) is inserted into the bottom of the inner cavity of the tail gas washing tower (8) and is located below the liquid level of the process water.

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