Device and method for removing butter from waste lye through extraction coalescence coupling

Abstract

The invention relates to a device and a method for removing butter through extraction, coalescence and coupling of waste lye. The device is composed of a Y-shaped flange filter, a micro-mixing extractor, a shaft type coalescence filtering device, a horizontal coalescence separating device, a settling tank and the like. The spent lye and the extraction agent are subjected to liquid drop micro-dispersion and mixed liquid reinforced mixing in the micro-mixing extraction module to improve the butter extraction efficiency, and after coalescence and demulsification of oleophylic / hydrophilic particles and fibers in the shaft type coalescence module and the horizontal coalescence separation module, oil-water two-phase layering is completed in the sedimentation area; suspended matters in the mixed liquid are intercepted in the filtering module; and the oil phase floats upwards and is collected at the top to be discharged regularly. By introducing an extraction coalescence coupling process and combining micro-extraction enhanced mixing and a demulsification function of hydrophilic and hydrophobic particles, efficient removal of various oils in the waste alkali liquid is realized. The device is compact in structure, and has wide applicability to treatment of high-oil-content suspended wastewater and extraction treatment of high-concentration organic wastewater, especially treatment of complex wastewater containing high-viscosity oil.

Description

Technical Field

[0001] The invention relates to a waste alkali solution extraction and coalescence coupling grease removal device and a grease removal method, belonging to the field of petrochemical industry. Background Art

[0002] In some processes in the field of petrochemicals and coal chemical industry, such as catalytic cracking and hydrocracking, the sulfides in the crude oil will react with hydrogen under high temperature and high pressure to convert into acidic gases such as hydrogen sulfide, and then these acidic gases will be removed by alkali washing technology. However, this process produces waste lye rich in complex oil pollutants, among which high concentration (2% to 30%) butter is particularly prominent. This is a polymer formed by the reaction of unsaturated hydrocarbons with aldehydes and ketones. It has high emulsification and exists in the form of floating, suspension, and attachment to solid surfaces. Its high viscosity and low-temperature coking characteristics increase the difficulty of treatment. In addition, the waste lye is also mixed with dissolved oil, iron filings and suspended matter, which further increases the difficulty of treatment. The current waste lye treatment system often encounters blockage problems due to design limitations (such as small tower diameter and packing), resulting in low operating efficiency and frequent shutdowns for maintenance. Given the unstable butter content and numerous impurities in the waste lye, traditional extraction, membrane technology, adsorption and coalescence filtration methods often face bottlenecks such as easy blockage, difficult maintenance, and incomplete oil-water separation.

[0003] To solve the above problems, the present invention innovatively introduces the extraction and coalescence coupling process, which achieves efficient removal of various forms of oil in waste alkali liquid, ensures the continuous and stable operation of the equipment, is easy to operate, and is energy-saving and environmentally friendly. This innovative solution is of great significance for improving the treatment efficiency of waste alkali liquid and promoting resource recycling. Summary of the invention

[0004] In view of the problems and defects of the existing technology and equipment, the present invention provides a waste alkali liquid oil removal process and device coupled with extraction and agglomeration, based on micro-extraction enhanced mixing, the demulsification function of hydrophilic and hydrophobic particles and the enhanced demulsification and agglomeration performance of hydrophilic and hydrophobic fibers.

[0005] The technical solution adopted by the present invention is as follows:

[0006] A waste alkali solution extraction and coalescence coupling oil removal device, characterized in that the device comprises two Y-type flange filters, a buffer tank, a micro-mixing extractor, an axial coalescence filtering device, a horizontal coalescence separation device, a sedimentation tank, and an overflow tank in sequence: the two Y-type flange filters are respectively connected to the extractant inlet at the bottom end of the micro-mixing extractor and the waste alkali solution inlet on the lower side wall through two buffer tanks, an ejector is arranged at the bottom of the micro-mixing extractor, a reducing pipe with spiral shearing blades is arranged at the top, and an extractor mixed liquid outlet is arranged at the top to connect the first mixed liquid inlet of the axial coalescence filtering device;

[0007] The axial coalescence filtering device comprises two coalescence filtering tanks connected in series, wherein the first mixed liquid outlet of the first tank located at the bottom of the tank is connected to the second mixed liquid inlet of the second tank located at the side of the tank by a pipeline, the first mixed liquid inlet is arranged on the upper side of the first tank, and the second mixed liquid outlet is arranged at the bottom of the second tank, each coalescence filtering tank is provided with a cavity filled with particle fillers, each coalescence tank is formed by stacking particles of different sizes, which are fine particles and coarse particles from top to bottom, each coalescence filtering tank is provided with an oil bag connected to the first sewage outlet at the top, a water bag connected to the first or second mixed liquid outlet at the bottom, and a backwash water inlet and a backwash gas inlet at the bottom side;

[0008] The horizontal coalescence separation device comprises a horizontal tank body and a cavity filled with fiber fillers arranged inside the horizontal tank body, the third mixed liquid inlet at the front end of the horizontal tank body is connected to the second mixed liquid outlet of the axial coalescence filtration device, and the third mixed liquid outlet is arranged at the bottom of the tank body;

[0009] The middle part of the sedimentation tank is filled with corrugated plates, and a vent and a second sewage outlet are provided on the top. The tank wall has two upper and lower circular observation mirrors, which are connected to the third mixed liquid outlet of the horizontal coalescence separation device through the fourth mixed liquid inlet at the top, and connected to the overflow tank through the water phase outlet at the bottom.

[0010] The particle filler filled in the axial coalescence filtration device is a heterophilic hydrophobic dispersed particle layer, the diameter and height ratio of the cavity filled with the particle filler is 1:10 to 1:8, the diameter and height ratio of the oil bag and the water bag is 1:3 to 1:2, and the ratio of the cavity diameter to the tank diameter is 1:2 to 2:3.

[0011] The particle size of the fine particle filler is 0.2-0.5 mm, and the particle size of the coarse particle filler is 0.5-1.2 mm.

[0012] The fiber filler filled in the horizontal coalescence separation device is a heterogeneous composite fiber layer, which is woven from hydrophilic fibers and oleophilic fibers, and the fibers and the tank body are interference fit.

[0013] The present invention also provides a waste alkali solution extraction and coalescence coupling butter removal method using the waste alkali solution butter removal device, characterized in that the method comprises the following steps:

[0014] S1, waste alkali liquor and extractant enter the buffer tank through the Y-type flange filter respectively, the extractant is dispersed and mixed in the waste alkali liquor to form micro droplets through the ejector of the micro-mixing extractor, and the mixed liquid after preliminary dispersion enters the variable diameter pipeline with spiral shearing blades for cyclone shearing, and multiple stages of alternating mixing, crushing and extraction are performed;

[0015] S2, the mixed liquid obtained in step S1 enters the shaft-type coalescing and filtering device, in the first coalescing and filtering tank, the butter and suspended matter in the waste alkali solution are filtered and intercepted, part of the mixed liquid droplets are demulsified and coalesced to complete the initial two-phase separation, and part of the mixed liquid droplets are not demulsified;

[0016] S3, the mixed liquid droplets obtained in step S2 enter the second coalescing and filtering tank, and the large droplets in the mixed liquid that have not completed stratification and demulsification are coalesced and separated;

[0017] S4, the mixed liquid obtained in step S3 is deeply separated by a horizontal coalescence separation device unit, and the tiny droplets coalesce and grow in the microchannels of the fiber filler bed layer, completing the two-phase separation with the extractant droplets;

[0018] S5, the extractant and treated water separated in step S4 are settled in a settling tank, the extractant layer floats up and is discharged from the top outlet, and the treated water layer sinks and flows into the overflow tank from the lower water phase outlet;

[0019] S6. The fresh treated water and the deposited treated water flowing into the overflow tank in step S5 are discharged from corresponding outlets respectively.

[0020] The present invention has the following beneficial effects:

[0021] 1. The present invention provides a continuously running extraction-coagulation coupled waste alkali liquor oil removal process and device, the device comprising a filtration module, a micro-mixing extraction module, a secondary axial coalescence module, a horizontal coalescence separation module, a tank body and a sedimentation tank. The micro-mixing extraction module disperses the extractant droplets into the waste alkali liquor through an internal nozzle, and then utilizes the module collision and the waste alkali liquor to enhance the extraction effect; then utilizes the primary particle coalescence filter bed to achieve the initial oil droplet coalescence and growth, and then utilizes the secondary particle coalescence filter bed to achieve the deep coalescence and separation of the unstratified droplets after growth; finally, the fiber coalescence module completes the deep demulsification, coalescence and separation of oil in water and water in oil, and after a short period of sedimentation in the clarification zone, the water phase is discharged from the bottom and the oil phase is discharged from the top.

[0022] 2. During operation, in order to ensure the treatment effect, the system is equipped with a backwash route to prevent the high-concentration suspended matter in the waste alkali liquid and the viscous butter from adhering to and accumulating rapidly in the screening section of the particle module. The valve can be opened and closed to adjust the steam to release steam bubbles to make the hydrophilic and hydrophobic particles fluffy in the fluidized expansion bag and expand the porosity of the particles. The particle module is cleaned under the impact of the incoming liquid and the explosion of the steam bubbles, and the impurities float up and gather at the top of the equipment for sewage discharge.

[0023] 3. Compared with the traditional treatment method, the present invention adopts a new treatment method of extraction and coalescence coupling, which can realize equipment backwashing while completing high-precision and effective oil removal. The present invention has a compact structure, small footprint, fast extraction and mass transfer, high efficiency, simple operation, energy saving and consumption reduction, and is suitable for all high-oil and suspended wastewater treatment and high-concentration organic wastewater extraction treatment, especially complex wastewater treatment containing high-viscosity oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the waste alkali solution extraction coalescence coupling butter removal device of the present invention;

[0025] Figure 2 This is a schematic diagram of the buffer tank structure;

[0026] Figure 3 It is a schematic diagram of the structure of a micro-mixing extraction device;

[0027] Figure 4 It is a schematic diagram of the structure of the shaft-type coalescence filtration device;

[0028] Figure 5 Schematic diagram of the structure of the horizontal coalescence separation device

[0029] Figure 6 It is a schematic diagram of the structure of the sedimentation tank device;

[0030] Wherein: 1. filter; 2. buffer tank; 3. pump; 4. micro-mixing extractor; 5. axial coalescing filter; 6. horizontal coalescing separation device; 7. sedimentation tank; 8. overflow tank; 9. flow meter; 1-1. first mixed liquid inlet; 1-2. first mixed liquid outlet; 1-3. second mixed liquid inlet; 1-4. second mixed liquid outlet; 2-1. vent; 2-2. sewage outlet; 2-3. pressure gauge; 2-4. observation mirror; 2-5 outlet; 2-6. outer cylinder; 2-7 inlet; 4-1. mixed liquid outlet; 4-2 spiral blade; 4-3 variable diameter pipe; 4-4. ejector; 4-5. extractant inlet; 4 -6, waste alkali liquid inlet; 4-7 outer cylinder; 5-1, first sewage outlet; 5-2, oil bag; 5-3, observation mirror; 5-4, water bubbling; 5-5, filling particles; 5-6 water bag; 5-7, mixed liquid outlet; 5-8, backwash water inlet; 5-9, backwash steam inlet; 5-10, outer cylinder; 5-11, mixed liquid inlet; 6-1 third mixed liquid inlet; 6-2 outer cylinder; 6-3, fiber filler; 6-4 third mixed liquid outlet; 7-1, vent; 7-2, second sewage outlet 7-3, observation mirror; 7-4, corrugated plate; 7-5, treated water outlet; 7-6, outer cylinder; 7-7, fourth mixed liquid inlet. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below in conjunction with examples. It should be understood that the following examples are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by professionals and technicians in this field based on the content of the present invention still belong to the scope of protection of the present invention.

[0032] Example 1

[0033] Figure 1 The invention discloses a method and device for removing oil from waste alkali liquor by extracting and coalescing, wherein the waste alkali liquor oil removal device by extracting and coalescing comprises a filter 1, a buffer tank 2, a micro-mixing extractor 4, an axial coalescing filter 5 and a horizontal coalescing separation device 6. Most of the suspended matter and solid impurities in the waste alkali liquor and the extractant are filtered and separated in the filter 1; the waste alkali liquor and the extractant are fully mixed and extracted in the micro-mixing extractor 4; when the mixed liquid enters the axial coalescing filter 5 through the first mixed liquid inlet 1-1, the remaining suspended matter and solid impurities are intercepted in the primary coalescing particle module, and the oil-water two-phase droplets are initially coalesced and separated; then the mixture is subjected to deep coalescing and separation in the secondary coalescing particle module, and the separation of suspended oil and dispersed oil is completed through the particle coalescing part; then the mixture enters the horizontal coalescing separation device 6 to perform deep demulsification and coalescing separation on the emulsified oil with a micro-particle size; then the mixture enters the settling tank 7 for stratification, with the oil phase floating and the water phase sinking. During operation, the accumulation of suspended matter and solid impurities in the particle agglomeration part will affect the oil removal effect. Therefore, a backwash water inlet 5-8 and a backwash steam inlet 5-9 are provided. Clean water and steam are used to make the particles float, roll, and expand the porosity in the device to achieve particle cleaning. The suspended matter and solid impurities are discharged through the first sewage outlet 5-1.

[0034] The waste alkali liquid deoiling method using the above device has the following steps:

[0035] (1) The waste alkali liquor and the extractant are filtered through the filter 1 to complete the filtration of most of the suspended matter and solid impurities, the pressure is buffered and the flow is adjusted in the buffer tank, the enhanced extraction process is completed through the micro-mixing extractor 4, and then enter the axial coalescing filter device 5 to capture, coalesce and separate the suspended oil and the dispersed oil;

[0036] (2) The mixed liquid after the separation of the suspended oil and the dispersed oil enters the horizontal coalescing separation device 6 to demulsify and separate the emulsified oil with micro-particle size, and then enters the settling tank 7 to complete the oil-water separation;

[0037] (3) During the operation, the suspended matter and solid impurities accumulate in the particle agglomeration part, which will affect the oil removal effect. Therefore, a backwash water inlet 5-8 and a backwash steam inlet 5-9 are provided. The particles are floated, rolled, and the porosity is expanded in the device through clean water and steam to achieve particle cleaning. The suspended matter and solid impurities are discharged through the first sewage outlet 5-1. During the cleaning process, water is continuously inletted and discharged until the outlet water sample is clear and free of impurities.

[0038] Example 2

[0039] The method and device of the present invention were used in a pilot test of oil removal effect in an ethylene production plant. The waste alkali liquid after oil removal was subjected to subsequent biochemical treatment, and the extraction agent was pyrolysis gasoline, a by-product of ethylene production, to save costs.

[0040] The skid frame of the device is 1950mm long, 60mm wide and 1580mm high. The particle bed is about 700mm high and is stacked with oleophilic and hydrophilic particles of different sizes. The fiber bed is interference fit with the tank body and is about 400mm long. It is woven with hydrophilic and oleophilic fibers. The capacity of the buffer tank and sedimentation tank is about 3L.

[0041] The processing capacity of this experiment is 4L / h, and the amount of cracking gasoline is 4L / h, that is, the ratio of waste alkali liquid to extractant is 1:1; the oil content in the waste alkali liquid fluctuates between 10000 and 150000 mg / L. After a period of stable operation, samples are taken at the outlet, and the oil removal and suspension removal effects of the device are evaluated using an infrared oil meter and a turbidity meter. The results are shown in Table 1.

[0042] Table 1

[0043]

Claims

1. A waste alkali solution extraction coalescence coupling butter removal device, characterized in that: The device comprises two Y-shaped flange filters, a buffer tank, a micro-mixing extractor, an axial coalescing filter device, a horizontal coalescing separation device, a sedimentation tank, and an overflow tank in sequence: the two Y-shaped flange filters are respectively connected to the extractant inlet at the bottom end of the micro-mixing extractor and the waste alkali solution inlet at the lower side wall through two buffer tanks; an ejector is arranged at the bottom of the micro-mixing extractor, a reducing pipe with spiral shearing blades is arranged at the top, and an extractor mixed liquid outlet is arranged at the top to connect to the first mixed liquid inlet of the axial coalescing filter device; The axial coalescence filtering device comprises two coalescence filtering tanks connected in series, wherein the first mixed liquid outlet of the first tank located at the bottom of the tank is connected to the second mixed liquid inlet of the second tank located at the side of the tank by a pipeline, the first mixed liquid inlet is arranged on the upper side of the first tank, and the second mixed liquid outlet is arranged at the bottom of the second tank, each coalescence filtering tank is provided with a cavity filled with particle fillers, each coalescence tank is formed by stacking particles of different sizes, which are fine particles and coarse particles from top to bottom, each coalescence filtering tank is provided with an oil bag connected to the first sewage outlet at the top, a water bag connected to the first or second mixed liquid outlet at the bottom, and a backwash water inlet and a backwash gas inlet at the bottom side; The horizontal coalescence separation device comprises a horizontal tank body and a cavity filled with fiber fillers arranged inside the horizontal tank body, the third mixed liquid inlet at the front end of the horizontal tank body is connected to the second mixed liquid outlet of the axial coalescence filtration device, and the third mixed liquid outlet is arranged at the bottom of the tank body; The middle part of the sedimentation tank is filled with corrugated plates, and a vent and a second sewage outlet are provided on the top. The tank wall has two upper and lower circular observation mirrors, which are connected to the third mixed liquid outlet of the horizontal coalescence separation device through the fourth mixed liquid inlet at the top, and connected to the overflow tank through the water phase outlet at the bottom.

2. The waste alkali solution extraction coalescence coupling butter removal device according to claim 1, characterized in that: The particle filler filled in the axial coalescence filtration device is a heterophilic hydrophobic dispersed particle layer, the diameter and height ratio of the cavity filled with the particle filler is 1:10 to 1:8, the diameter and height ratio of the oil bag and the water bag is 1:3 to 1:2, and the ratio of the cavity diameter to the tank diameter is 1:2 to 2:

3.

3. The waste alkali solution extraction coalescence coupling butter removal device according to claim 1, characterized in that: The particle size of the fine particles of the particle filler is 0.2-0.5 mm, and the particle size of the coarse particles is 0.5-1.2 mm.

4. The waste alkali solution extraction coalescence coupling butter removal device according to claim 1, characterized in that: The fiber filler filled in the horizontal coalescence separation device is a heterogeneous composite fiber layer, which is woven from hydrophilic fibers and oleophilic fibers, and the fibers and the tank body are interference fit.

5. A method for removing butter by waste alkali solution extraction, coalescence and coupling using the device described in claims 1-4, characterized in that: The method comprises the following steps: S1, waste alkali liquor and extractant enter the buffer tank through the Y-type flange filter respectively, the extractant is dispersed and mixed in the waste alkali liquor to form micro droplets through the ejector of the micro-mixing extractor, and the mixed liquid after preliminary dispersion enters the variable diameter pipeline with spiral shearing blades for cyclone shearing, and multiple stages of alternating mixing, crushing and extraction are performed; S2, the mixed liquid obtained in step S1 enters the shaft-type coalescing and filtering device, in the first coalescing and filtering tank, the butter and suspended matter in the waste alkali solution are filtered and intercepted, part of the mixed liquid droplets are demulsified and coalesced to complete the initial two-phase separation, and part of the mixed liquid droplets are not demulsified; S3, the mixed liquid droplets obtained in step S2 enter the second coalescing and filtering tank, and the large droplets in the mixed liquid that have not completed stratification and demulsification are coalesced and separated; S4, the mixed liquid obtained in step S3 is deeply separated by a horizontal coalescence separation device unit, and the tiny droplets coalesce and grow in the microchannels of the fiber filler bed layer, completing the two-phase separation with the extractant droplets; S5, the extractant and treated water separated in step S4 are settled in a settling tank, the extractant layer floats up and is discharged from the top outlet, and the treated water layer sinks and flows into the overflow tank from the lower water phase outlet; S6. The fresh treated water and the deposited treated water flowing into the overflow tank in step S5 are discharged from corresponding outlets respectively.

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