Recycling device for waste gas and waste water containing ethylene oxide

Abstract

The utility model relates to the technical field of treatment of waste gas and waste water containing ethylene oxide, and particularly discloses a recycling device for waste gas and waste water containing ethylene oxide, which comprises a tail gas washing tower, and the top of the tail gas washing tower is connected with a CO2 purification and recovery unit through a first pipeline; the middle of the tail gas washing tower is connected with an EO waste gas emission unit through a sixth pipeline, the bottom of the tail gas washing tower is connected with a centrifugal pump through a seventh pipeline, the centrifugal pump is connected with a rich absorption liquid inlet of the EO device through a ninth pipeline, and the top of the tail gas washing tower is further connected with a second pipeline. Equipment facilities are reduced, the occupied area of the device is reduced, and the construction cost of the device is reduced; replacement water of a liquid ring vacuum pump of an original vacuum unit is changed into barren liquor of the EO device from desalted water, the consumption of desalted water is reduced, and the energy consumption of the device is reduced; no sewage is generated, the three-waste treatment cost of the device is reduced, and environmental protection is facilitated; after the rich liquid is conveyed to the EO device, EO, ethylene glycol materials and the like in the rich liquid can be recycled, and material loss is reduced.

Description

Technical Field

[0001] This utility model relates to the field of ethylene oxide-containing waste gas and wastewater treatment technology, specifically to a resource recycling device for ethylene oxide-containing waste gas and wastewater. Background Technology

[0002] The EC / DMC unit generates EO-containing waste gas and wastewater during production. The EO-containing waste gas primarily originates from the pressure control exhaust gas from the EC reaction unit and the exhaust gas from the vacuum unit of the EC evaporation and purification unit. The EO-containing wastewater mainly consists of the replacement water from the liquid ring vacuum pump in the vacuum system.

[0003] like Figure 2 As shown, the original design used demineralized water as the replacement water for the liquid ring vacuum pump in the vacuum system. After replacement, the water was treated as EO-containing wastewater. An EO tail gas scrubbing tower and an EO hydration reactor were added to absorb EO in the waste gas and convert it into ethylene glycol before sending it to the wastewater treatment facility for disposal. The drawbacks of this approach are: the addition of many facilities results in a large investment; excessive consumption of demineralized water increases the energy consumption of the device; a large amount of wastewater is generated, increasing the disposal cost and being detrimental to environmental protection. Therefore, a resource recycling device for ethylene oxide-containing waste gas and wastewater is provided. Utility Model Content

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a device for the resource recycling of ethylene oxide-containing waste gas and wastewater, thereby solving the problems mentioned in the background section.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a resource recycling device for ethylene oxide-containing waste gas and wastewater, comprising a tail gas scrubbing tower. The top of the tail gas scrubbing tower is connected to a CO2 purification and recovery unit via a first pipe. The middle part of the tail gas scrubbing tower is connected to an EO waste gas emission unit via a sixth pipe. The bottom of the tail gas scrubbing tower is connected to a centrifugal pump via a seventh pipe. The centrifugal pump is connected to the rich absorbent inlet of the EO device via a ninth pipe. The top of the tail gas scrubbing tower is also connected to a second pipe. One end of the second pipe is connected to the lean absorbent outlet of the EO device. The second pipe is connected to a vacuum system via a third pipe. The vacuum system is connected to the tail gas scrubbing tower via a fourth pipe.

[0006] In a preferred embodiment of this invention, a fifth pipe is connected to the sixth pipe, and the fifth pipe is connected to a vacuum system.

[0007] As a preferred embodiment of this utility model, the first pipeline is connected to the incinerator via a connecting pipe.

[0008] As a preferred embodiment of this utility model, the ninth pipe is connected to the exhaust gas scrubbing tower via the eighth pipe.

[0009] Compared with the prior art, the beneficial effects of this utility model are:

[0010] This device only adds a tail gas absorption tower, introduces lean liquid from the EO unit to the EC / DMC unit, uses a small portion as water for the vacuum system's liquid ring vacuum pump to replace water, and after replacement, sends it to the tail gas absorption tower to absorb EO in the waste gas. Most of it is directly sent to the tail gas absorption tower to absorb EO in the waste gas. The bottom of the tail gas absorption tower is the rich absorbent liquid after EO absorption, which is sent back to the EO unit for recycling treatment via a pump.

[0011] The advantages of this utility model are: reduced equipment and facilities, reduced plant footprint, and reduced plant construction costs; the replacement water of the original vacuum unit liquid ring vacuum pump is changed from demineralized water to lean liquid of the EO unit, reducing the consumption of demineralized water and reducing plant energy consumption; no wastewater is generated, reducing the cost of waste disposal of the plant, and is also beneficial to environmental protection; after the rich liquid is sent to the EO unit, EO, ethylene glycol and other materials can be recovered, reducing material loss. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of this utility model;

[0013] Figure 2 This is a structural schematic diagram of the background technology of this utility model.

[0014] In the diagram: 1. Tail gas scrubbing tower; 2. Vacuum system; 3. Incinerator; 4. CO2 purification and recovery unit; 5. Lean absorbent outlet of EO unit; 6. First pipeline; 7. Second pipeline; 8. Third pipeline; 9. Fourth pipeline; 10. Fifth pipeline; 11. Sixth pipeline; 12. Seventh pipeline; 13. Eighth pipeline; 14. Ninth pipeline; 15. Rich absorbent inlet of EO unit; 16. Centrifugal pump. Detailed Implementation

[0015] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more definite definition of the scope of protection of the present invention.

[0016] Example: Please refer to Figure 1This utility model provides a technical solution: a resource recycling device for ethylene oxide-containing waste gas and wastewater, including a tail gas scrubbing tower 1. The top of the tail gas scrubbing tower 1 is connected to a CO2 purification and recovery unit 4 through a first pipe 6. The middle part of the tail gas scrubbing tower 1 is connected to an EO waste gas emission unit through a sixth pipe 11. The bottom of the tail gas scrubbing tower 1 is connected to a centrifugal pump 16 through a seventh pipe 12. The centrifugal pump 16 is connected to the EO device rich absorbent inlet 15 through a ninth pipe 14. The top of the tail gas scrubbing tower 1 is also connected to a second pipe 7. One end of the second pipe 7 is connected to the EO device lean absorbent outlet 5. The second pipe 7 is connected to a vacuum system 2 through a third pipe 8. The vacuum system 2 is connected to the tail gas scrubbing tower 1 through a fourth pipe 9.

[0017] The sixth pipe 11 is connected to the fifth pipe 10, which is connected to the vacuum system to evacuate and maintain the required vacuum level for the process. The EC distillation unit and the EC purification unit need to operate under vacuum. The liquid ring vacuum pump of the vacuum system needs to use a liquid (usually water or oil) as the working medium to create a vacuum.

[0018] The first pipeline 6 is connected to the incinerator 3 via a connecting pipe. This is the in-plant incinerator, used for burning the top tail gas. Additionally, the top tail gas can also be sent to the CO2 purification and recovery unit as supplementary feedstock when CO2 feedstock is insufficient.

[0019] The ninth pipe 14 is connected to the tail gas scrubbing tower 1 through the eighth pipe 13 to protect the pump body and maintain the minimum backflow of the pump. In addition, it can also be used for system self-circulation when the rich liquid cannot be sent out.

[0020] Working principle: A resource recycling device for ethylene oxide-containing waste gas and wastewater. EO is easily soluble in water. Relying on the existing lean and rich liquid system of the upstream EO unit, a branch is taken to the EC / DMC unit for recycling.

[0021] The process is as follows: A branch of the lean absorbent from the EO unit is sent to the EC / DMC unit. Most of it is directly fed into the tail gas scrubber 1 to absorb EO in the waste gas. A small portion is first used as the working fluid for the liquid ring vacuum pump of the vacuum system. Water is added and drained simultaneously. After displacement, the water is pumped into the tail gas scrubber 1 to continue absorbing EO in the waste gas. After absorbing EO, the lean liquid becomes rich liquid, which is pumped from the bottom of the tail gas scrubber 1 to the rich liquid main pipe of the EO unit for EO stripping. The rich liquid after EO recovery becomes lean liquid again, and the cycle continues.

[0022] This invention only adds a tail gas absorption tower 1 to introduce lean liquid from the EO device to the EC / DMC device. A small portion is used as water for the vacuum system liquid ring vacuum pump to replace water. After replacement, the water is sent to the tail gas absorption tower 1 to absorb EO in the waste gas. Most of the water is sent directly to the tail gas absorption tower 1 to absorb EO in the waste gas. The bottom of the tail gas absorption tower is the rich absorbent liquid after EO absorption, which is sent back to the EO device for recycling treatment by a pump.

[0023] The above embodiments merely illustrate the implementation of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make several modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model.

Claims

1. An ethylene oxide-containing waste gas waste water resource recycling device, comprising a tail gas washing tower (1), characterized in that: The top of the tail gas washing tower (1) is connected with the CO2 purification and recovery unit (4) through the first pipeline (6), the middle of the tail gas washing tower (1) is connected with the EO waste gas discharge unit through the sixth pipeline (11), the bottom of the tail gas washing tower (1) is connected with the centrifugal pump (16) through the seventh pipeline (12), the centrifugal pump (16) is connected with the EO device rich absorbent liquid inlet (15) through the ninth pipeline (14), the top of the tail gas washing tower (1) is also connected with the second pipeline (7), one end of the second pipeline (7) is connected with the EO device lean absorbent liquid outlet (5), the second pipeline (7) is connected with the vacuum system (2) through the third pipeline (8), the vacuum system (2) is connected with the tail gas washing tower (1) through the fourth pipeline (9).

2. The oxirane-containing waste gas and waste water recycling device according to claim 1, characterized in that: The fifth pipeline (10) is connected with the vacuum system on the sixth pipeline (11).

3. The oxirane-containing waste gas and waste water recycling device according to claim 1, characterized in that: The first pipeline (6) is connected with the incinerator (3) through the connecting pipe.

4. The oxirane-containing waste gas and waste water recycling device according to claim 1, characterized in that: The ninth pipeline (14) is connected with the tail gas washing tower (1) through the eighth pipeline (13).

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