Device for removing butter in DMTO production process

Abstract

The utility model discloses a device for removing butter in a DMTO production process, and belongs to the technical field of methanol-to-olefin production. Through a pure physical method, butter in concentrated water at the rear end of the sewage stripping tower is subjected to accelerated demulsification, aggregation and separation, so that the energy load of the system is reduced, and the oil content in the concentrated water is reduced. The device is formed by sequentially connecting a multi-medium filtering tank, a first-stage demulsification tank, a first-stage separation tank, a second-stage demulsification tank and a second-stage separation tank in series through pipelines, a regulating valve and a flow meter are arranged on a concentrated water outlet pipeline at the bottom of the second-stage separation tank, and the operation pressure and the treatment flow of the device are controlled through the regulating valve according to the reading of the flow meter. The device can sensitively control the feeding amount of concentrated water, reduce the butter content in the concentrated water, reduce the burden of the system and improve the utilization rate of recycled water; according to the device disclosed by the utility model, high-efficiency removal of butter is realized by adopting a pure physical method, the operation cost is greatly reduced, and the oil content of concentrated water is reduced by about 53.3% by using the device disclosed by the utility model.

Description

Technical Field

[0001] The utility model belongs to the technical field of methanol to olefin production, and specifically relates to a device for removing butter in a DMTO production process. More specifically, the device is a device for accelerating the demulsification, aggregation and separation of butter in concentrated water at the rear end of a sewage stripping tower by a purely physical method, thereby reducing the energy load of the system and the oil content in the concentrated water. Background Art

[0002] Coal-to-methanol-to-olefins (DMTO) is a core technology in the emerging coal chemical industry, boasting considerable market penetration and market share. As more DMTO plants enter commercial operation, problems are emerging during the long production cycle. The concentrated water after treatment in the stripping tower, in addition to containing soluble oxygenated compounds such as alcohols, ethers, and ketones, is often contaminated with floating oil and severely emulsified. Recycling the oxygenated compounds in the concentrated water can increase olefin yields, but the oily substances may adversely affect the entire reaction system. If the concentrated water is not recycled and discharged directly as wastewater, the treatment of this type of oil-containing emulsion is inherently challenging, placing new pressure on the company's environmental protection efforts. Faced with this working condition, there are four commonly used treatment methods, namely the butter inhibitor method: adding chemical reagents such as inhibitors, antioxidants, metal passivators and dispersants to reduce the production of butter from the source, but the reagents are expensive and costly, and other chemical additives will be introduced into the system, which poses a hidden danger; optimizing the operating parameters of the alkali washing tower: controlling the oxygen in the tower and optimizing the concentration of the alkali washing section, which need to be adjusted according to different process times. The process is cumbersome and cannot be solved in the long term; cleaning the butter in the alkali washing tower: opening the can for cleaning, the reaction needs to be stopped, and the processing process is troublesome; solvent dissolution: selecting a suitable solvent to dissolve the butter, and then separating it, which cannot be achieved through online operation.

[0003] Therefore, a physical treatment method for DMTO concentrate water is needed that requires high oil-water separation accuracy, a certain degree of resistance to fouling and clogging, adaptability to the complexity of coal-to-olefin concentrate water, and industrial-scale application. The device adopted in this utility model integrates demulsification and separation, with a simple process, low investment and operating costs, simple operation, and sensitive control, effectively removing butter from the concentrate water. Utility Model Content

[0004] The purpose of this utility model is to provide a device for removing butter from the DMTO production process. This device utilizes a series of functional tanks to remove catalyst powder from concentrated water in a multi-media filler tank. A demulsifier demulsifies small oil droplets in the concentrated water, causing them to aggregate at the top of the tank due to a significant difference in oil and water density, forming a butter layer. In a separator tank, the water phase passes through, while the oil phase aggregates at the top of the tank, allowing the butter to be collected. This device is simple, practical, and effective in efficiently removing butter from the concentrated water at the rear end of the wastewater stripping tower in the DMTO production process, while minimizing impact on the normal operation of the entire production process.

[0005] The utility model discloses a device for removing butter in a DMTO production process, which is composed of a multi-media filter tank, a first-stage demulsification tank, a first-stage separation tank, a second-stage demulsification tank and a second-stage separation tank which are connected in series in sequence through pipelines. A first-stage demulsification tank oil drain port, a first-stage separation tank oil drain port, a second-stage demulsification tank oil drain port and a second-stage separation tank oil drain port are respectively provided on the tops of the tank bodies of the first-stage demulsification tank, the first-stage separation tank, the second-stage demulsification tank oil drain port and the second-stage separation tank. Drain ports are provided in the middle of the first-stage demulsification tank and the second-stage demulsification tank and at the bottoms of the first-stage separation tank and the second-stage separation tank. A second pressure gauge, a third pressure gauge, a fourth pressure gauge and a fifth pressure gauge are respectively provided on the pipelines connecting the multi-media filter tank, the first-stage demulsification tank, the first-stage separation tank, the second-stage demulsification tank and the second-stage separation tank. A first pressure gauge is provided on the inlet pipeline of the multi-media filter tank. A regulating valve and a flow meter are provided on the concentrated water outlet pipeline at the bottom of the second-stage separation tank. The operating pressure and processing flow of the device are controlled by the regulating valve according to the flow meter readings.

[0006] The multi-media filter tank is filled with corrugated plate filler to filter the catalyst particles in the concentrated water; the first-level demulsification tank and the second-level demulsification tank are filled with demulsification filter elements, both of which adopt the inside-out method. The accuracy of the demulsification filter element of the second-level demulsification tank is higher than that of the first-level demulsification tank (the accuracy of the demulsification filter element of the second-level demulsification tank is 5μm, and the separation accuracy of the second-level separation tank is 100μm). The first-level demulsification tank is used to aggregate large oil droplets, and the second-level demulsification tank is used to aggregate small oil droplets; the first-level separation tank and the second-level separation tank are filled with hydrophilic oil-blocking filter elements, both of which adopt the outside-inside-out method to block the floating oil formed after demulsification. The accuracy of the hydrophilic oil-blocking filter element of the second-level separation tank is higher than that of the first-level separation tank (the accuracy of the demulsification filter element of the first-level demulsification tank is about 15μm, and that of the first-level separation tank is about 200μm); the separation of the oil phase and the water phase in each tank adopts gravity sedimentation, with the oil phase on the top and the water phase on the bottom.

[0007] The concentrated water from the rear end of the wastewater stripping tower in the DMTO production process enters from the bottom of the multi-media filter tank through the inlet pipe, filters and removes the catalyst powder, and flows out from the top of the multi-media filter tank; the concentrated water flowing out from the top of the multi-media filter tank enters from the bottom of the first-stage demulsification tank, and the oil phase formed after demulsification is discharged from the oil outlet of the first-stage demulsification tank, and the water phase is discharged from the middle of the first-stage demulsification tank; the water phase discharged from the middle of the first-stage demulsification tank enters from the middle of the first-stage separation tank, and the oil phase formed after hydrophilic oil blocking is discharged from the oil outlet of the first-stage separation tank, and the water phase is discharged from the bottom of the first-stage separation tank; the water phase discharged from the bottom of the first-stage separation tank enters from the bottom of the second-stage demulsification tank, and the oil phase formed after further demulsification is discharged from the oil outlet of the second-stage demulsification tank, and the water phase is discharged from the middle of the second-stage demulsification tank; the water phase discharged from the middle of the second-stage demulsification tank enters from the middle of the second-stage separation tank, and the oil phase formed after further hydrophilic oil blocking is discharged from the oil outlet of the second-stage separation tank, and the water phase is discharged from the bottom of the second-stage separation tank; the concentrated water discharged from the bottom of the second-stage separation tank is discharged to the subsequent process after passing through a regulating valve and a flow meter.

[0008] The beneficial effects of the utility model are:

[0009] 1. Sensitively control the amount of concentrated water introduced, reduce the butter content in the concentrated water, reduce the system burden, and improve the utilization rate of recycled water;

[0010] 2. Pure physical method realizes efficient removal of butter, greatly reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 : A schematic structural diagram of the device of the utility model;

[0012] The names of each part are: multi-media filter tank 1, first-level demulsification tank 2, first-level separation tank 3, second-level demulsification tank 4, second-level separation tank 5, first-level demulsification tank oil drain port I, first-level separation tank oil drain port II, second-level demulsification tank oil drain port III, second-level separation tank oil drain port IV, first pressure gauge P0, second pressure gauge P1, third pressure gauge P2, fourth pressure gauge P3, fifth pressure gauge P4, regulating valve 6, flow meter 7. Specific implementation methods

[0013] Example 1:

[0014] A device for removing butter from a DMTO production process is connected to a wastewater stripping tower. The concentrated water produced by the tower top reflux tank is turbid, milky white, and yellowish, with a water temperature of approximately 63°C. By adjusting the opening of the valve before the outlet of the concentrated water (oil content ~1500 mg / L), the front-end operating pressure P0 of the device is controlled at 0.1 MPa, and the flow rate is 100 L / h. The concentrated water passes through a multi-media filter tank 1, a primary demulsifier 2, a primary separator 3, a secondary demulsifier 4, and a secondary separator 5 in sequence. The concentrated water enters the bottom of the multi-media filter tank 1 and exits from the top. The concentrated water enters the bottom of the primary demulsifier 2, with oil discharged from the top (oil outlet I) and water discharged from the middle. The concentrated water enters the middle of the primary separator 3, with oil discharged from the top (oil outlet II) and water discharged from the bottom. The concentrated water enters the lower part of the secondary demulsifier 4, with oil discharged from the top (oil outlet III) and water discharged from the middle. The concentrated water enters the middle of the secondary separator 5, with oil discharged from the top (oil outlet IV) and water discharged from the bottom. The separation device is equipped with pressure gauges (P0-P4), a regulating valve 6, and a flowmeter 7. The operating pressure and flow rate are controlled by the regulating valve 6 based on the flowmeter 7 readings. The oil drain port is located at the top of the tank, and the pressure gauge is located on the pipeline between the two tanks. The pressure data for each tank during operation are shown in Table 1.

[0015] Table 1: Pressure data of each tank

[0016]

[0017] Table 2: Oil output data over a period of time

[0018] time Oil output 2024.05.19-2024.05.23 100–150 mL / h 2024.05.24-2024.06.02 200–250 mL / h

[0019] Table 1 shows that the tank operating pressure decreases with the flow direction of the concentrated water. Table 2 shows that the sum of the oil discharge volumes of the primary demulsifier 2 and the secondary demulsifier 4 during the initial operation (May 19, 2024 - May 23, 2024) was maintained at 100-150 mL / h, and the sum of the oil discharge volumes during the later operation (May 24, 2024 - June 2, 2024) was maintained at 200-250 mL / h, achieving a good oil discharge effect and promoting the separation rate of butter and water. The oil discharge volumes of the primary separation tank 3 and the secondary separation tank 5 were maintained at approximately 100 mL / h, and the oil content at the concentrated water outlet was approximately 700 mg / L. By using the device described in the present invention, the oil content of the concentrated water was reduced by approximately 53.3%.

Claims

1. A device for removing butter in a DMTO production process, characterized by: The invention comprises a multi-media filter tank (1), a first-stage demulsification tank (2), a first-stage separation tank (3), a second-stage demulsification tank (4) and a second-stage separation tank (5) which are sequentially connected in series through pipelines. A first-stage demulsification tank oil discharge port (I), a first-stage separation tank oil discharge port (II), a second-stage demulsification tank oil discharge port (III) and a second-stage separation tank oil discharge port (IV) are respectively provided on the tops of the first-stage demulsification tank (2), the first-stage separation tank (3), the second-stage demulsification tank (4) and the second-stage separation tank (5). A drain port is provided at the bottom of the multi-media filter tank (1), the first demulsification tank (2), the first separation tank (3), the second demulsification tank (4) and the second separation tank (5); a second pressure gauge (P1), a third pressure gauge (P2), a fourth pressure gauge (P3) and a fifth pressure gauge (P4) are provided on the pipelines connecting the multi-media filter tank (1), the first demulsification tank (2), the first separation tank (3), the second demulsification tank (4) and the second separation tank (5), respectively; a first pressure gauge (P0) is provided on the inlet pipeline of the multi-media filter tank (1); and a regulating valve (6) and a flow meter (7) are provided on the concentrated water outlet pipeline at the bottom of the second separation tank (5).

2. The device for removing butter in a DMTO production process according to claim 1, wherein: The multi-media filter tank (1) is filled with corrugated plate filler.

3. The device for removing butter in a DMTO production process according to claim 1, wherein: The first-stage demulsification tank (2) and the second-stage demulsification tank (4) are filled with demulsification filter cores, both of which adopt an inside-out method. The precision of the demulsification filter core of the second-stage demulsification tank (4) is higher than that of the first-stage demulsification tank (2).

4. The device for removing butter in a DMTO production process according to claim 1, wherein: The first-stage separation tank (3) and the second-stage separation tank (5) are filled with hydrophilic oil-blocking filter elements, both of which adopt an outside-in and inside-out method. The precision of the hydrophilic oil-blocking filter element in the second-stage separation tank (5) is higher than that of the hydrophilic oil-blocking filter element in the first-stage separation tank (3).

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