Heavy alcohol recycling system for EO and EC devices

Abstract

The utility model discloses a heavy alcohol recycling system for EO and EC devices, which comprises a crude ethylene glycol tank, a dehydrating tower, an MEG refining tower and a DEG refining tower which are sequentially connected with heavy alcohol of the EO device and heavy alcohol of the EC device, the scheme can realize refining and recycling of MEG and DEG in the EO device and the EC device, the recycling efficiency of the heavy alcohol is effectively improved, and the emission of heavy alcohol hazardous waste and the hazardous waste treatment cost are reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to heavy alcohol back refining purification field, specifically to a kind of heavy alcohol back refining system for EO, EC device. BACKGROUND

[0002] In prior art, EC (epoxy chloropropane) device EG (ethylene glycol) refining system operation produces part heavy alcohol, its main component is DEG (diethylene glycol), MEG (monoethylene glycol) and other heavy components, and the proportion is about 88.43%, 6.58%, 4.99% respectively, and currently, as dangerous waste, the treatment cost is about 970 yuan / ton. And the EG refining system of EO (ethylene oxide) also produces part heavy alcohol, and the main components of EC device heavy alcohol and EO device heavy alcohol are close. At present, the heavy alcohol of EC device is treated as dangerous waste, and the heavy alcohol back refining device of EO device has the defect of low recovery rate, and the prior art has not combined EC device and EO device to carry out heavy alcohol back refining system, therefore, it is urgent to design a heavy alcohol recovery device shared by EO device and EC device, to improve DEG, MEG recovery rate, reduce dangerous waste discharge and dangerous waste treatment cost. SUMMARY

[0003] In view of the deficiencies of the prior art, the technical problem to be solved by the utility model is to provide a DEG, MEG recovery rate high EO, EC device heavy alcohol back refining system, to reduce dangerous waste discharge and dangerous waste treatment cost.

[0004] To solve the above problems, the utility model provides the following technical scheme:

[0005] A kind of heavy alcohol back refining system for EO, EC device, including EC device heavy alcohol and the crude ethylene glycol tank for storing EO device heavy alcohol, the discharge end of EC device heavy alcohol is connected with pipe line one and pipe line two in parallel, pipe line one is communicated with heavy alcohol tank, pipe line two is communicated with crude ethylene glycol tank;The discharge end of crude ethylene glycol tank is communicated with the feed end of dehydration tower by crude ethylene glycol pump, the discharge end of dehydration tower bottom is communicated with the feed end of MEG refining tower by dehydration tower kettle liquid pump, the top discharge end of MEG refining tower is sequentially connected with MEG product intermediate tank and MEG product tank;The discharge end of MEG refining tower bottom is communicated with DEG refining tower by MEG refining tower kettle liquid pump, the top discharge end of DEG refining tower is sequentially connected with DEG product intermediate tank and DEG product tank, and the discharge end of DEG refining tower bottom is communicated with heavy alcohol tank by DEG refining tower kettle liquid pump.

[0006] The utility model discloses a technical scheme still includes, the dehydration tower bottom discharge end still is equipped with dehydration tower reboiler, and the discharge end of dehydration tower reboiler is communicated with the dehydration tower reboiler feed port of dehydration tower lateral wall, the bottom discharge end of MEG refining tower still is communicated with MEG refining tower reboiler, and the discharge end of MEG refining tower reboiler is communicated with the MEG refining tower reboiler feed port of MEG refining tower lateral wall, the bottom discharge end of DEG refining tower still is communicated with DEG refining tower reboiler, and the discharge end of DEG refining tower reboiler is communicated with the DEG refining tower reboiler feed port of DEG refining tower lateral wall.

[0007] The utility model discloses a technical scheme still includes, and the discharge end of MEG refining tower kettle liquid pump is parallelly connected with the feed end of pipeline three and pipeline four, and the discharge end of pipeline three is communicated with DEG refining tower feed end, and the discharge end of DEG refining tower kettle liquid pump is also communicated with the feed end of pipeline four, and the discharge end of pipeline four is communicated with heavy alcohol tank, and is equipped with tower bottom cooler on pipeline four.

[0008] The utility model discloses a technical scheme still includes, and the top discharge end of DEG refining tower is communicated with the feed end of circulating pipeline, and the discharge end of circulating pipeline is communicated with the feed end of MEG refining tower.

[0009] The utility model discloses a technical scheme still includes, and the top of MEG refining tower is equipped with MEG tower condenser, and the top of MEG tower condenser and dehydration tower is all communicated with injection system, and injection system is communicated with sewage pool.

[0010] The recycling method of the heavy alcohol recycling system for the EO and EC device includes the following steps:

[0011] (1) a part of the heavy alcohol generated by the EC device is transported to the heavy alcohol tank through pipeline one, and another part is transported to the crude ethylene glycol tank for storing the heavy alcohol of the EO device through pipeline two;

[0012] (2) the heavy alcohol stored in the crude ethylene glycol tank is first dried through the dehydration tower, and the dehydrated heavy alcohol enters the MEG refining tower through the dehydration tower kettle liquid pump to be refined to obtain MEG products, which are stored in the MEG product tank through the MEG product intermediate tank, so as to realize MEG recycling;

[0013] (3) the kettle liquid of the MEG refining tower is transported to the DEG refining tower through the MEG refining tower kettle liquid pump to be refined to obtain DEG products, which are stored in the DEG product tank through the DEG product intermediate tank, so as to realize DEG recycling;

[0014] (4) the kettle liquid of the DEG refining tower is transported to the heavy alcohol tank through the DEG refining tower kettle liquid pump to be stored as hazardous waste.

[0015] The MEG refining tower is provided with a sensitive plate, and the temperature of the sensitive plate is set to 139-140 DEG C. The bottom liquid of the MEG refining tower in step (3) is partly transported to the DEG refining tower through pipeline three for DEG refining, and the other part is transported to the heavy alcohol tank through pipeline four. The bottom liquid of the DEG refining tower and the bottom liquid of the MEG refining tower in pipeline four are cooled by the bottom cooler before entering the heavy alcohol tank. The material separated by evaporation at the top of the DEG refining tower is transported to the MEG refining tower through the circulating pipeline for MEG circulating refining.

[0016] The beneficial effects of the present application are as follows:

[0017] Compared with the prior art, the purpose of the present application is to provide a heavy alcohol recycling system for EO and EC devices with high DEG and MEG recovery rate, thereby reducing the discharge and treatment cost of hazardous waste, and achieving the above technical effects. The present application provides a heavy alcohol recycling device shared by the EO device and the EC device. The heavy alcohol of the EO device and the heavy alcohol of the EC device are combined and then dried in the dehydration tower, and then refined by the MEG refining tower to obtain MEG products. The MEG products are refined by the DEG refining tower to obtain DEG products, thereby effectively realizing the refining and recycling of heavy alcohol in the EO device and the EC device, improving the recycling efficiency, and reducing the discharge and treatment cost of hazardous waste. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the description of the embodiments or the prior art will be briefly introduced. Obviously, other drawings can also be obtained by those skilled in the art without creative labor.

[0019] Figure 1 The structure of the heavy alcohol recycling system for EO and EC devices in the specific embodiment is shown in the figure.

[0020] 1 is a crude glycol tank, 2 is a pipeline one, 3 is a pipeline two, 4 is a heavy alcohol tank, 5 is a crude glycol pump, 6 is a dehydration tower, 7 is a dehydration tower bottom liquid pump, 8 is a MEG refining tower, 9 is a dehydration tower reboiler, 10 is a MEG product intermediate tank, 11 is a MEG product tank, 12 is a MEG refining tower bottom liquid pump, 13 is a DEG refining tower, 14 is a MEG refining tower reboiler, 15 is a MEG tower condenser, 16 is a jet system, 17 is a sewage tank, 18 is a DEG product intermediate tank, 19 is a DEG product tank, 20 is a DEG refining tower bottom liquid pump, 21 is a DEG refining tower reboiler, 22 is a circulating pipeline, 23 is a pipeline three, 24 is a pipeline four, and 25 is a bottom cooler. DETAILED DESCRIPTION

[0021] In order to enable personnel in the technical field to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application.

[0022] In the description of the present application, it should be understood that the terms "center", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of simplifying the description of the present application, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0023] As can be seen from the drawings, a heavy alcohol refining system for EO and EC devices comprises an EC device heavy alcohol and a crude ethylene glycol tank 1 for storing an EO device heavy alcohol, a pipe 1 and a pipe 2 are connected in parallel at the discharge end of the EC device heavy alcohol, the pipe 1 is communicated with a heavy alcohol tank 4, and the pipe 2 is communicated with the crude ethylene glycol tank 1.

[0024] The discharge end of the crude ethylene glycol tank 1 is communicated with the feed end of a dehydration tower 6 through a crude ethylene glycol pump 5, the discharge end of the bottom of the dehydration tower 6 is communicated with the feed end of a MEG refining tower 8 through a dehydration tower kettle liquid pump 7, and the discharge end of the bottom of the dehydration tower 6 is also provided with a dehydration tower reboiler 9, the discharge end of the dehydration tower reboiler 9 is communicated with the dehydration tower reboiler feed port in the side wall of the dehydration tower 6.

[0025] The top discharge end of the MEG refining tower 8 is sequentially communicated with a MEG product intermediate tank 10 and a MEG product tank 11; the bottom discharge end of the MEG refining tower 8 is communicated with a DEG refining tower 13 through a MEG refining tower kettle liquid pump 12, and the bottom discharge end of the MEG refining tower 8 is also communicated with a MEG refining tower reboiler 14, the discharge end of the MEG refining tower reboiler 14 is communicated with the MEG refining tower reboiler feed port in the side wall of the MEG refining tower 8. The MEG tower condenser 15 is arranged at the top of the MEG refining tower 8, the top of the MEG tower condenser 15 and the top of the dehydration tower 6 are communicated with a jet system 16, and the jet system 16 is communicated with a sewage pool 17.

[0026] The top discharge end of the DEG refining tower 13 is sequentially communicated with a DEG product intermediate tank 18 and a DEG product tank 19, the bottom discharge end of the DEG refining tower 13 is communicated with the heavy alcohol tank 4 through a DEG refining tower kettle liquid pump 20, and the bottom discharge end of the DEG refining tower 13 is also communicated with a DEG refining tower reboiler 21, and the discharge end of the DEG refining tower reboiler 21 is communicated with a DEG refining tower reboiler feed port located on the side wall of the DEG refining tower 13. The top discharge end of the DEG refining tower 13 is communicated with the feed end of a circulation pipeline 22, and the discharge end of the circulation pipeline 22 is communicated with the feed end of the MEG refining tower 8.

[0027] The discharge end of the MEG refining tower kettle liquid pump 12 is connected in parallel with the feed end of pipeline three 23 and pipeline four 24, the discharge end of pipeline three is communicated with the feed end of the DEG refining tower, the discharge end of the DEG refining tower kettle liquid pump 20 is also communicated with the feed end of pipeline four 24, the discharge end of pipeline four 24 is communicated with the heavy alcohol tank 4, and a tower bottom cooler 25 is arranged on pipeline four 24.

[0028] The heavy alcohol back-refining method of the heavy alcohol back-refining system for the EO and EC device comprises the following steps:

[0029] (1) A part of the heavy alcohol generated by the EC device is transported to the heavy alcohol tank 4 through pipeline one 2, and another part is transported to the crude ethylene glycol tank 1 for storing the heavy alcohol of the EO device through pipeline two 3.

[0030] (2) The heavy alcohol stored in the crude ethylene glycol tank 1 is first dried by the dehydration tower 6, and the dehydrated heavy alcohol is transported into the MEG refining tower 8 through the dehydration tower kettle liquid pump 7 to perform MEG refining, and the obtained MEG product is stored in the MEG product tank 11 through the MEG product intermediate tank 10 to realize MEG recovery, wherein a sensitive plate is arranged in the MEG refining tower 8, and the temperature of the sensitive plate is set to 139-140℃.

[0031] (3) A part of the kettle liquid of the MEG refining tower 8 is transported to the DEG refining tower 13 through pipeline three 23 to perform DEG refining, and another part is transported to the heavy alcohol tank 4 through pipeline four 24. The temperature of the middle and lower sections of the DEG refining tower 13 is set to 142℃, the obtained DEG product is stored in the DEG product tank 19 through the DEG product intermediate tank 18 to realize DEG recovery, and the material separated by evaporation at the top of the DEG refining tower 13 is transported to the MEG refining tower 8 through the circulation pipeline 22 to perform MEG circulation refining.

[0032] (4) The kettle liquid of the DEG refining tower 13 is transported to the heavy alcohol tank 4 through the DEG refining tower kettle liquid pump 20 to be stored as hazardous waste. The kettle liquid of the DEG refining tower 13 and the kettle liquid of the MEG refining tower 8 in pipeline four are cooled by the tower bottom cooler 25 before entering the heavy alcohol tank 4.

[0033] Through the above heavy alcohol recycling device, on the basis of the existing production capacity of the applicant, taking the heavy alcohol recycling amount of the EC device as an example, it is calculated that the heavy alcohol recycling amount of the EC device is about 4 tons / day, all the MEG is recycled, and about 50% (wt) DEG is recycled, the production cost is saved about (MEG / DEG product income + heavy alcohol hazardous waste treatment cost saving) about 12200 yuan / day, 4160000 yuan is saved per year (calculated on the basis of 340 days of stable production per year), at the same time, the cost of treating hazardous waste heavy alcohol is greatly reduced. The specific calculation is as follows:

[0034] The recovery income of industrial-grade MEG product (market price about 4100 yuan / ton) is about: 4x6.58% x4100≈1080 yuan / day.

[0035] The recovery income of DEG product (market price about 5200 yuan / ton) is about: 4x88.43% x50% x5200≈9197 yuan / day.

[0036] The heavy alcohol hazardous waste treatment cost saving (treatment cost about 970 yuan / ton) is about: (4x6.58%+4x88.43% x50%) x970≈1970 yuan / day.

[0037] Per year: (according to 340 days of budget) (1080+9197+1970) x340 / 10000≈4160000 yuan.

[0038] The recycling method of the heavy alcohol recycling system of the EO and EC devices of the present application effectively improves the heavy alcohol recovery rate, effectively reduces the cost of treating hazardous waste heavy alcohol, significantly saves the production cost, reduces the hazardous waste emission, and has significant economic and environmental benefits.

[0039] Although the present application has been described in detail with reference to the preferred embodiments, the present application is not limited thereto. Various equivalent modifications or replacements can be made to the embodiments of the present application by those skilled in the art without departing from the spirit and essence of the present application, and these modifications or replacements should be within the scope of the present application. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A heavy alcohol reprocessing system for EO and EC units, characterized in that: The system includes a heavy ethanol tank for the EC unit and a crude ethylene glycol tank for storing the heavy ethanol from the EO unit. The discharge end of the heavy ethanol from the EC unit is connected in parallel to two pipelines: pipeline one connects to the heavy ethanol tank, and pipeline two connects to the crude ethylene glycol tank. The discharge end of the crude ethylene glycol tank is connected to the feed end of the dehydration tower via a crude ethylene glycol pump. The bottom discharge end of the dehydration tower is connected to the feed end of the MEG refining tower via a dehydration tower bottom liquid pump. The top discharge end of the MEG refining tower is sequentially connected to a MEG product intermediate tank and a MEG product tank. The bottom discharge end of the MEG refining tower is connected to the DEG refining tower via a MEG refining tower bottom liquid pump. The top discharge end of the DEG refining tower is sequentially connected to a DEG product intermediate tank and a DEG product tank. The bottom discharge end of the DEG refining tower is connected to the heavy ethanol tank via a DEG refining tower bottom liquid pump.

2. The heavy alcohol reprocessing system for the EO and EC units according to claim 1, characterized in that: The bottom discharge end of the dehydration tower is also equipped with a dehydration tower reboiler, and the discharge end of the dehydration tower reboiler is connected to the dehydration tower reboiler inlet on the side wall of the dehydration tower; the bottom discharge end of the MEG refining tower is also connected to a MEG refining tower reboiler, and the discharge end of the MEG refining tower reboiler is connected to the MEG refining tower reboiler inlet located on the side wall of the MEG refining tower; the bottom discharge end of the DEG refining tower is also connected to a DEG refining tower reboiler, and the discharge end of the DEG refining tower reboiler is connected to the DEG refining tower reboiler inlet located on the side wall of the DEG refining tower.

3. The heavy alcohol reprocessing system for the EO and EC units according to claim 1, characterized in that: The discharge end of the MEG refining tower bottom liquid pump is connected in parallel to the inlet ends of pipes three and four. The discharge end of pipe three is connected to the inlet end of the DEG refining tower, and the discharge end of the DEG refining tower bottom liquid pump is also connected to the inlet end of pipe four. The discharge end of pipe four is connected to the heavy alcohol tank, and a bottom cooler is installed on pipe four.

4. The heavy alcohol reprocessing system for the EO and EC units according to claim 1, characterized in that: The top discharge end of the DEG refining tower is connected to the feed end of the circulation pipeline, and the discharge end of the circulation pipeline is connected to the feed end of the MEG refining tower.

5. The heavy alcohol reprocessing system for EO and EC units according to claim 1, characterized in that: The top of the MEG refining tower is equipped with a MEG tower condenser. The tops of both the MEG tower condenser and the dehydration tower are connected to a spray system, which is connected to a wastewater tank.

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