Device and method for contact extraction and separation of fiber reinforced liquid membrane

Abstract

The invention provides a fiber-reinforced liquid membrane contact extraction and separation device and method. The device comprises a combined tank body, a reverse spraying and mixing unit, a liquid membrane contact extraction unit and a reinforced separation unit, according to the method, extraction of dispersive liquid drops on impurities in a continuous phase is realized in the contact extraction unit, and separation of micro-dispersive phase liquid drops in the continuous phase is realized in the combined enhanced separation unit. The liquid membrane contact extraction technology, the fiber coalescence separation technology and the inclined plate separation technology are combined into an integrated coupling separation system, the device has the advantages of being simple in equipment and convenient to operate, compared with the prior art, the mass transfer area of dispersion liquid drops and a continuous phase is greatly increased, the mass transfer rate is increased, and the mass transfer efficiency is improved. And the problems of serious emulsification and liquid drop entrainment are avoided.

Description

Technical Field

[0001] The invention relates to the field of petrochemical industry, and in particular to a device and method for fiber-reinforced liquid membrane contact extraction and separation. Background Art

[0002] Extraction is a method of transferring solute from one solvent to another by utilizing the different solubility or distribution coefficient of substances in mutually immiscible (or slightly soluble) solvents. The extraction process does not cause changes in the chemical composition of the extracted substance (or no chemical reaction occurs), so the extraction operation is a physical process. The operation of separating the two immiscible liquids after extraction is called liquid separation. As a commonly used separation method, extraction separation has been widely used in hydrometallurgy, pharmaceuticals, petrochemicals, environment, nuclear fuels, biochemicals and other industries.

[0003] In industrial equipment, extraction separation generally uses packing, trays or static mixers to increase the effective contact area between the oil and water phases. These methods all use mixing and stirring methods to break up the two phases into dispersed small droplets, increase the contact area between the two phases, and improve the reaction rate. However, after the reaction process is completed, sufficient reaction time and separation equipment must be used to separate the oil and alkali phases, otherwise it is easy to cause oil and alkali entrainment or even serious emulsification problems.

[0004] Fiber liquid membrane contactor is a new type of high-efficiency mass transfer equipment, which is widely used in liquefied gas refining and desulfurization and other occasions. Fiber liquid membrane contactor uses the large surface tension between alkali solution and fiber to transform alkali droplets into liquid film attached to the fiber surface, and realizes the extraction of non-hydrocarbon impurities in liquefied gas by alkali solution on the liquid film. The existence of liquid film greatly increases the mass transfer area between alkali solution and liquefied gas, and improves the reaction rate. When using fiber liquid membrane contactor, it has the advantages of low alkali dosage, high mercaptan removal rate, low operating cost, no alkali solution carryover, and low waste alkali production. It is particularly suitable for liquefied gas desulfurization treatment and can ensure that the total sulfur of refined liquefied gas meets the requirements.

[0005] Patent 201510459076.5 discloses a device and method for removing water and metal salts from crude oil. Water and metal salts in crude oil are removed by a water-washed fiber liquid membrane contactor to ensure that the quality of the treated crude oil meets industrial requirements. The fillers in the contactor include tube sheets, fiber cores, support rings and stainless steel wire mesh. The disadvantages of this method are: conventional fiber cores, wire mesh fillers and stainless steel wires are used as mass transfer internals, the extraction efficiency of impurities such as metal salts is low, and it is easy to cause entrainment of water-washed liquid droplets.

[0006] Patents 201810321135.6 and 201610449572.7 both propose methods for fine desulfurization of liquid hydrocarbons such as liquefied gas, carbon three, carbon four, and carbon five. The main feature is that a single-stage, two-stage, or multi-stage fiber liquid membrane contactor is used as an extraction device to extract and remove hydrogen sulfide, extract and remove carbonyl sulfide, extract and remove mercaptans, and solvent reverse extraction to remove disulfide, etc., wherein the fiber liquid membrane contactor is often provided with a hydrophilic modified fiber filament inner core, and the fiber filament is in a continuous corrugated shape. The first desulfurizer and carbon five are in a certain proportion in the form of a liquid film between the hydrophilic modified fiber filaments in the fiber liquid membrane contactor to fully contact with each other in the form of a liquid film, and complete the desulfurization of organic sulfur such as hydrogen sulfide, carbonyl sulfide, mercaptans, and carbon disulfide. The disadvantage of this method is that the fiber filament inner core has a low efficiency of enhanced extraction desulfurization, and it is difficult to completely remove organic sulfur, and it needs to be further removed by a second desulfurizer or multi-stage extraction.

[0007] Patent 201810083165.8 discloses a method for combined processing of catalytic cracking oil slurry. The fiber liquid membrane is used for purification and solid removal. After the diluted oil slurry contacts water in the fiber liquid membrane contactor, the solid powder in the oil slurry enters the water under the action of amphoteric surfactant with hydrophilic properties, thereby achieving the effect of desolidification of the oil slurry. The disadvantage of this method is that the solid powder easily causes the fiber liquid membrane contactor to be blocked, and the service life is not long.

[0008] Patent 202221187191.3 discloses a fiber liquid membrane mass transfer reactor. By distributing the corrugated fiber filaments and the straight fiber filaments at intervals on the tube sheet, the anti-clogging ability of the fiber liquid membrane mass transfer reactor can be improved while ensuring the fiber liquid membrane mass transfer mechanism. The disadvantage of this method is that the mass transfer efficiency of the liquid membrane flowing on the corrugated fiber filaments and the straight fiber filaments is not high.

[0009] The existing fiber liquid membrane contact technology still has problems of unstable extraction and low extraction efficiency, which limits the wide application of liquid membrane contactors in the industrial field. Therefore, it is necessary to further develop a fiber-reinforced liquid membrane contact extraction and separation device and method with simple operation and controllable fiber liquid membrane to be suitable for different extraction and separation processes. Summary of the invention

[0010] In order to overcome the problems existing in the existing liquid membrane contact extraction technology in the extraction process, such as single liquid membrane flow, unstable extraction, low mass transfer efficiency, etc., the present invention provides a fiber-reinforced liquid membrane contact extraction and separation device and method.

[0011] The present invention combines the liquid film contact extraction technology, fiber coalescence separation technology, and inclined plate separation technology into an integrated coupled separation system; in the contact extraction unit, the surface tension between the dispersed phase and the spindle knot fibers is used to transform the droplets into a liquid film attached to the fiber surface, and the dispersed droplets extract impurities in the continuous phase on the liquid film; in the enhanced separation unit, the affinity fibers and corrugated plates are used to coalesce, grow, and settle the micro-dispersed phase droplets after extraction, so as to separate the micro-dispersed phase droplets in the continuous phase. The device and method of the present invention have the characteristics of simple equipment and convenient operation. The method can effectively overcome the problems existing in the prior art, greatly increase the mass transfer area between the dispersed droplets and the continuous phase, improve the mass transfer rate, and avoid the more serious problems of emulsification and droplet entrainment compared to the prior art.

[0012] To achieve the above technical objectives, the present invention provides a device and method for fiber-reinforced liquid membrane contact extraction and separation, which can further improve the efficiency of mass transfer reactions, wherein the fiber filaments with a spindle structure provide a larger two-phase contact area, making the mass transfer reaction more sufficient and efficient.

[0013] The present invention specifically adopts the following technical solutions:

[0014] A fiber-reinforced liquid membrane contact extraction and separation device, characterized in that the device comprises:

[0015] A vertical cylinder is located at the upper part of the front end of the horizontal cylinder and is connected to the horizontal cylinder. A continuous phase liquid inlet is opened at the top of the vertical cylinder, and a dispersed phase liquid inlet is opened at the upper side. A reverse spray mixing unit and a liquid film contact extraction unit are arranged from top to bottom inside the vertical cylinder. A clean continuous phase liquid outlet is opened at the upper rear side of the horizontal cylinder, and a dispersed phase liquid outlet is opened at the bottom of the liquid bag at the lower rear side. An enhanced separation unit is arranged in the middle of the horizontal cylinder.

[0016] The reverse spray mixing unit is composed of a plurality of spray heads, which are arranged on a ring pipeline connected to the dispersed phase liquid inlet.

[0017] The liquid membrane contact extraction unit is a fiber filler filled with multiple spindle knot fibers, each spindle knot fiber is vertically installed in the upper and lower porous plates connected to the edge of the inner wall of the vertical cylinder.

[0018] The strengthening separation unit is composed of a fiber filler layer and a corrugated plate layer, and the corrugated plate layer is arranged closely behind the fiber filler layer;

[0019] A circulation pump is arranged between the dispersed phase liquid inlet and the dispersed phase liquid outlet.

[0020] Furthermore, the porosity of the spindle knot fiber filler is 30-70%, and the length of the spindle knot fiber is 2-5D1, wherein D1 is the inner diameter of the vertical cylinder.

[0021] Furthermore, the spindle node fiber diameter d is 0.5-5 mm, the spindle node distance P is 10-50 mm, the spindle node width a is 2-10 d, and the spindle node length b is 2-15 a.

[0022] Furthermore, the spindle knot fibers may be arranged vertically in parallel or in staggered arrangement. When the fibers are arranged vertically in parallel, the distance between the fibers is 4 to 10a, and when the fibers are arranged vertically in staggered arrangement, the distance between the fibers is 2 to 8a.

[0023] Furthermore, the fiber filler and the corrugated plate are both made of affinity materials, the fiber filler thickness is 100-300 mm, and the corrugated plate thickness is 200-500 mm, wherein affinity means that the contact angle of the dispersed phase on the material in the continuous phase environment is less than 50°;

[0024] A fiber-reinforced liquid membrane contact extraction and separation method, the method comprising the following steps:

[0025] (a) The light phase liquid is introduced as the continuous phase from the continuous phase inlet at the upper part of the vertical cylinder, and the spindle fibers are immersed in the light phase liquid. The heavy phase extraction liquid is introduced as the dispersed phase from the dispersed phase inlet at the upper end of the vertical cylinder. The extraction liquid is evenly sprayed into the continuous phase through the spray head for mixed mass transfer. Then the extraction liquid is distributed to the spindle fibers through the upper porous plate and moves downward in the form of a liquid film flow. The extraction liquid is fully in contact with the light phase liquid when flowing on the spindle fibers. After sufficient mass transfer, the extracted liquid gathers on the lower porous plate and flows into the horizontal cylinder through the porous channels. The large droplets of the heavy phase after extraction settle at the bottom of the horizontal cylinder, and the small droplets of the heavy phase are dispersed in the light phase liquid.

[0026] (b) The heavy phase droplets extracted in step (a) flow laterally with the light phase liquid in the horizontal cylinder. When passing through the fiber filler layer, the droplets gather and grow on the fibers, continue to grow through the corrugated plate layer, and then settle into the liquid bag at the bottom of the horizontal cylinder; the separated light phase liquid is discharged from the net continuous phase outlet at the top of the rear side of the horizontal cylinder, and the heavy phase extraction liquid is discharged from the dispersed phase outlet at the bottom of the liquid bag.

[0027] (c) Part of the heavy phase extract discharged from the dispersed phase outlet in step (b) is returned to the dispersed phase inlet after being passed through a circulation pump and added with fresh extract.

[0028] Furthermore, the flow ratio of the heavy phase extraction liquid to the light phase liquid is 1% to 10%.

[0029] Furthermore, the spraying direction of the spray head is opposite to the flow direction of the continuous phase, and the particle size of the sprayed dispersed phase droplets is 0.01 to 1 mm.

[0030] Furthermore, the light phase liquid may be a light phase liquid containing impurities, or may be an emulsified liquid obtained by mixing a light phase liquid containing impurities with an extract.

[0031] Beneficial effects:

[0032] Compared with the prior art, this application has the following technical effects:

[0033] (0) The system has simple process, easy operation, good controllability and stability;

[0034] (2) In the contact extraction unit, the spindle-shaped fiber provides a larger contact area between the two phases. Compared with the fiber core, wire mesh filler and stainless steel wire as mass transfer internals, the mass transfer reaction is more sufficient and efficient;

[0035] (3) In the enhanced separation unit, the affinity fibers and corrugated plates are used to aggregate, grow and settle the micro-dispersed phase droplets after extraction, so as to separate the micro-dispersed phase droplets in the continuous phase and avoid the more serious two-phase entrainment problem;

[0036] (4) The entire device requires few equipment and occupies a small area. In addition to being used for liquefied gas desulfurization, it also has broad application prospects in the refining process of crude oil, distillate oil, light tar, alkylate, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings are used to provide a further understanding of the present invention. They only constitute a part of this specification to further explain the present invention, and do not constitute a limitation of the present invention.

[0038] Figure 1 It is a schematic diagram of the overall structure of a fiber-reinforced liquid membrane contact extraction and separation device of the present invention.

[0039] Wherein: 1-continuous phase liquid inlet, 2-dispersed phase liquid inlet, 3-net continuous phase outlet, 4-dispersed phase liquid outlet, 5-vertical cylinder, 6-horizontal cylinder, 7-spray head, 8-upper porous plate, 9-lower porous plate, 10-porous channel, 11-spindle knot fiber, 12-fiber filler layer, 13-corrugated plate layer, 14-circulation pump.

[0040] Figure 2 This is a schematic diagram of a spindle knot fiber structure of the present invention.

[0041] FIG3 is a schematic diagram of the arrangement of the spindle knot fibers of the present invention; wherein: FIG3(a) is a parallel vertical arrangement, and FIG3(b) is a staggered vertical arrangement. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and technical advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein explain the present invention, but do not limit the present invention.

[0043] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0044] Embodiment 1:

[0045] A chemical plant uses the device and method of the present invention to carry out deacidification and desulfurization treatment on the sulfuric acid alkylation reaction product.

[0046] Process conditions: The product of sulfuric acid alkylation reaction is an acid-hydrocarbon mixture, and the hydrocarbon phase density is 691.9 kg / m 3 , dynamic viscosity is 0.53cP (10℃), density of sulfuric acid is 1814kg / m 3 , the dynamic viscosity is 32 cP (10°C), the sulfuric acid content in the reaction product is 100-250 mg / kg, and the sulfur content is 20-50 mg / kg.

[0047] Device conditions: Device as Figure 1 , Figure 2 As shown in Figure 3. The spindle knot fibers are evenly distributed in the cylinder in a ring shape and arranged vertically in a staggered manner, the fiber spacing is 20 mm, and the porosity of the spindle knot filler is 50%; the fibers are selected from spindle knot glass fibers, each fiber diameter d is 1 mm, the spindle knot spacing P is 20 mm, the spindle knot width a is 5 mm, and the spindle knot length b is 10 mm; the spindle knot fibers are staggered and arranged vertically, and the fiber spacing is 25 mm; the fiber filler and the corrugated plate are both made of acid-friendly materials, the fiber filler thickness is 150 mm, and the corrugated plate thickness is 300 mm; the flow ratio of alkali solution to liquefied gas is 5%.

[0048] Operation process: The sulfur-containing acid-hydrocarbon mixture enters from the continuous phase inlet 1 at the upper part of the vertical cylinder 5 as the continuous phase, and the sulfuric acid is distributed to the spindle knot fiber 11 through the upper porous plate 8 and moves downward in the form of a liquid film flow. The sulfuric acid fully contacts with the hydrocarbon phase when flowing on the fiber and extracts the sulfur in the hydrocarbon phase. After sufficient mass transfer, the sulfuric acid liquid gathers on the lower porous plate 9 and flows into the horizontal cylinder through the porous channel 10; the extracted small acid droplets flow laterally with the hydrocarbon phase liquid in the horizontal cylinder 6, and when passing through the fiber filler layer 12, the small droplets gather and grow on the fiber, and then continue to grow through the corrugated plate layer 13, and then settle to the liquid bag at the bottom of the horizontal cylinder; the separated hydrocarbon phase is discharged from the net continuous phase outlet 3 at the top of the rear side of the horizontal cylinder, and the heavy phase sulfuric acid is discharged from the dispersed phase outlet 4 at the bottom of the liquid bag.

[0049] Determination method: The organic acid content is determined by potentiometric titration according to GB / T 7304-2014, and the total sulfur content is determined by SH / T 0253-1992 "Determination of total sulfur content in light petroleum products (coulometric method)".

[0050] Application effect: After being treated by the method and device of the present invention, the sulfuric acid content in the purified reaction product is less than 5 mg / kg, and the total sulfur content is less than 2 mg / kg. Compared with the traditional alkaline water washing treatment method, the method of the present invention has a simple process and high desulfurization efficiency.

[0051] Embodiment 2:

[0052] A chemical plant adopts the device and method of the present invention in the process of desulfurization of coking liquefied gas.

[0053] Process conditions: liquefied gas temperature 30-40°C, pressure 2.4-2.5MPa, hydrogen sulfide content in liquefied gas 1000-20000mg / Nm 3 , mercaptan content 100~500mg / Nm 3 , the alkali solution is 15% NaOH solution.

[0054] Device conditions: Device as Figure 1 , Figure 2 As shown in Figure 3. The spindle fiber is evenly distributed in the cylinder in a ring shape and arranged vertically in parallel. The fiber spacing is 30 mm, and the porosity of the spindle packing is 70%. The fiber is selected from spindle 304 metal wire, each fiber diameter d is 1.5 mm, the spindle spacing P is 40 mm, the spindle width a is 5 mm, and the spindle length b is 15 mm. The fiber packing and the corrugated plate are both made of hydrophilic materials, the fiber packing thickness is 150 mm, and the corrugated plate thickness is 300 mm. The flow ratio of alkali solution to liquefied gas is 5%.

[0055] Operation process: liquefied gas as the continuous phase enters from the continuous phase inlet 1 at the upper part of the vertical cylinder 5, and alkali liquid as the dispersed phase is injected from the dispersed phase inlet 2 at the upper end of the vertical cylinder side. The alkali liquid is evenly sprayed into the continuous phase through the spray head 7 for mixed mass transfer; then the alkali liquid is distributed to the spindle knot fiber 11 through the upper porous plate 8 and moves downward in the form of liquid film flow. The alkali liquid fully contacts the liquefied gas on the fiber and extracts the mercaptan in the liquefied gas. After sufficient mass transfer, the alkali liquid gathers at The extracted heavy phase droplets flow horizontally with the light phase liquid in the horizontal cylinder 6. When passing through the fiber filler layer 12, the droplets gather and grow on the fibers, and then continue to grow through the corrugated plate layer 13, and then settle and separate into the liquid bag at the bottom of the horizontal cylinder. The separated light phase liquefied gas is discharged from the net continuous phase outlet 3 at the top of the rear side of the horizontal cylinder, and the heavy phase alkali liquid is discharged from the dispersed phase outlet 4 at the bottom of the liquid bag. The alkali liquid part discharged from the dispersed phase outlet is returned to the dispersed phase inlet 2 after passing through the circulation pump 14 and adding fresh alkali liquid.

[0056] Determination method: Use gas chromatography to detect the sulfide content.

[0057] Application effect: After being treated by the method and device of the present invention, the average removal rate of mercaptans in liquefied gas can reach 99.5%, the mass transfer efficiency is high, the entrainment of alkali solution is significantly reduced, and the removal efficiency is higher than that of the traditional process.

[0058] The above description is only a preferred embodiment of the present invention, and does not impose any limitation on the present invention. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A fiber-reinforced liquid membrane contact extraction and separation device, characterized in that: The device comprises: A vertical cylinder is located at the upper part of the front end of the horizontal cylinder and is connected to the horizontal cylinder. A continuous phase liquid inlet is opened at the top of the vertical cylinder, and a dispersed phase liquid inlet is opened at the upper side. A reverse spray mixing unit and a liquid film contact extraction unit are arranged from top to bottom inside the vertical cylinder. A clean continuous phase liquid outlet is opened at the upper rear side of the horizontal cylinder, and a dispersed phase liquid outlet is opened at the bottom of the liquid bag at the lower rear side. An enhanced separation unit is arranged in the middle of the horizontal cylinder. The reverse spray mixing unit is composed of a plurality of spray heads, which are arranged on a ring pipeline connected to the dispersed phase liquid inlet. The liquid membrane contact extraction unit is a fiber filler filled with multiple spindle knot fibers, each spindle knot fiber is vertically installed in the upper and lower porous plates connected to the edge of the inner wall of the vertical cylinder. The strengthening separation unit is composed of a fiber filler layer and a corrugated plate layer, and the corrugated plate layer is arranged closely behind the fiber filler layer; A circulation pump is arranged between the dispersed phase liquid inlet and the dispersed phase liquid outlet.

2. The fiber-reinforced liquid membrane contact extraction and separation device according to claim 1, characterized in that: The porosity of the spindle knot fiber filler is 30-70%, and the length of the spindle knot fiber is 2-5D1, wherein D1 is the inner diameter of the vertical cylinder.

3. The fiber-reinforced liquid membrane contact extraction and separation device according to claim 1, characterized in that: The spindle node fiber diameter d is 0.5-5 mm, the spindle node distance P is 10-50 mm, the spindle node width a is 2-10 d, and the spindle node length b is 2-15 a.

4. The fiber-reinforced liquid membrane contact extraction and separation device according to claim 1, characterized in that: The spindle knot fibers can be arranged vertically in parallel or in staggered arrangement. When the fibers are arranged vertically in parallel, the distance between the fibers is 4 to 10a. When the fibers are arranged vertically in staggered arrangement, the distance between the fibers is 2 to 8a.

5. The fiber-reinforced liquid membrane contact extraction and separation device according to claim 1, characterized in that: The fiber filler and the corrugated plate are both made of affinity materials, the fiber filler thickness is 100-300 mm, and the corrugated plate thickness is 200-500 mm, wherein the affinity means that the contact angle of the dispersed phase on the material in the continuous phase environment is less than 50°.

6. A method for fiber-reinforced liquid membrane contact extraction and separation, the method comprising the following steps: (a) A light phase liquid is introduced as a continuous phase from the continuous phase inlet at the upper part of the vertical cylinder, and the spindle knot fibers are immersed in the light phase liquid. A heavy phase extract is introduced as a dispersed phase from the dispersed phase inlet at the upper end of the vertical cylinder, and the extract is evenly sprayed into the continuous phase through a spray head for mixed mass transfer; then the extract is distributed to the spindle knot fibers through an upper porous plate, and moves downward in a liquid film state, and the extract is fully in contact with the light phase liquid when flowing on the spindle knot fibers. After sufficient mass transfer, the extract is gathered on the lower porous plate and flows into the horizontal cylinder through the porous channels, and the large heavy phase droplets after extraction settle at the bottom of the horizontal cylinder, and the small heavy phase droplets are dispersed in the light phase liquid; (b) the heavy phase droplets extracted in step (a) flow laterally with the light phase liquid in the horizontal cylinder, and when passing through the fiber filler layer, the droplets gather and grow on the fibers, and then continue to grow through the corrugated plate layer, and then settle into the liquid bag at the bottom of the horizontal cylinder; the separated light phase liquid is discharged from the net continuous phase liquid outlet at the upper rear side of the horizontal cylinder, and the heavy phase extraction liquid is discharged from the dispersed phase liquid outlet at the bottom end of the liquid bag; (c) Part of the heavy phase extract discharged from the dispersed phase outlet in step (b) is returned to the dispersed phase inlet after being passed through a circulation pump and added with fresh extract.

7. The method according to claim 6, characterized in that The flow rate ratio of the heavy phase extraction liquid to the light phase liquid is 1% to 10%.

8. The method according to claim 6, characterized in that The spraying direction of the spray head is opposite to the flow direction of the continuous phase, and the particle size of the dispersed phase droplets sprayed out is 0.01 to 1 mm.

9. The method according to claim 6, characterized in that: The light phase liquid is the impurity-containing light phase liquid or the emulsified liquid obtained by mixing the impurity-containing light phase liquid with the extract.

Images