CN100462123C - Method of using hollow fiber replacing liquid-film tech. to realize same stage extraction-back extraction - Google Patents

Abstract

A process for realizing the extraction-back extraction at same class by use of the hollow fibers updating liquid film technique features that the affinity between hollow fiber membrane and solvent phase is used to generate a very-thin solvent phase film on the one surface of hollow fiber membrane and the solute is selectively migrated between material phase and back extraction phase. Its advantages are high mass transfer efficiency, and high speed and selectivity for separating or concentrating solute.

Description

Utilize hollow fiber renewal liquid membrane technology to realize the method for extracting-back extraction at the same level

Technical field:

The present invention relates to a kind of method of utilizing hollow fiber renewal liquid membrane technology to realize extracting-back extraction at the same level.

Technical background:

Abstraction technique is one of most widely used isolation technics.Usually in liquid-liquid extraction, exist the restriction of mass transfer balance, cause the volume of separation equipment bigger.And carry out at two different equipment with back extraction in industrial extraction, also increased the complexity of technology and the difficulty of operation.And extracting-back extraction process at the same level can be carried out extraction and back extraction simultaneously, not only can make equipment compact more, thereby reduce process complexity and operation easier, and improve mass-transfer efficiency greatly.

Extracting-back extraction at the same level can be by following technology realization: 1. supported liquid membrane technology; 2. emulsion liquid membrane technology; 3. other liquid film technologies contain liquid film, doughnut sealing liquid film, support emulsion liquid membrane etc. as doughnut; 4. electrostatic quast liquid membrane; 5. separation process etc. is replaced in the reciprocal cross of interior coupling collection.

Supported liquid membrane (SLM) notion is meant the fluid film that the liquid film material forms in the space attached to porous inertia polymeric membrane by capillary siphoning and suction-operated, the porous inert polymer is the supporter of liquid film, both sides at supporter are flow through feed liquid and back washing agent respectively, finish certain extract and separate effect by the liquid film effect.

Document J Membr Sci, 1987,31 (2-3): in 117～145, people such as Danesi P R have studied the stability problem of supported liquid membrane, find because coating solution relies on surface tension and capillarity sorption in the duct of supporter, thus be easy to generate in the running coating solution feed liquid mutually with back extraction solution loss and membrane stability problems such as the pickup in fenestra road, obstruction mutually.

Document AIChE J, 1988,34:1135 and document Sep Sci and Tech, 1988, among the 23:1735, all proposed the notion that doughnut contains the liquid film assembly (Hollow fiber contained liquid membrane, HFCLM), this assembly is that two bundle porous hollow fibers are housed in a cavity, wherein a branch of feed liquid that flows through, another line is crossed strip liquor, and (shell side) then flows through film phase carrier solution between two intrafascicular hollow fiber outer walls.In this Liquid Membrane System, even the film liquid in the support membrane micropore is dissolved in feed liquid phase or the reception mutually, film liquid can be added in the micropore at any time, thereby has eliminated the liquid film life problems that supported liquid membrane runs off and causes because of coating solution.So this liquid film has better stability than supported liquid membrane.Its shortcoming is and since added the thicker relatively solvent of one deck mutually with two membranes mutually, caused the increasing of resistance to mass tranfer, thereby mass tranfer coefficient is less.The mass tranfer coefficient magnitude is 10 in the technology such as the supported liquid membrane of bibliographical information, doughnut containing liquid film ^-7, even littler.

Summary of the invention:

The present invention has proposed a kind of " hollow fiber renewal liquid membrane " technology, to realize extracting-back extraction process at the same level in order to overcome the shortcoming of said method.

The present invention utilizes hollow-fibre membrane and solvent affinity interaction mutually, make solvent form one deck solvent phase liquid film as thin as a wafer on the surface of hollow-fibre membrane one side, thereby play separately feed liquid and back extraction mutually, and the method for realization solute selective migration between feed liquid and back extraction mutually.

Fig. 1 is the used assembly schematic diagram of hollow fiber renewal liquid membrane technology, and wherein 1 for being equipped with the membrane contactor of one group of hollow-fibre membrane, 2. tube side flow control valve, 3. shell side flow control valve, 4. tube side inlet, 5. tube side outlet, 6. shell side inlet, 7. shell side outlet.Now in conjunction with Fig. 1 this technology is specifically described, the concrete operations step is as follows:

A flows through membrane contactor with extraction phase and deionized water from tube side inlet (4) and shell side inlet (6) respectively, and adjustable pipe, shell side pressure are poor, prevent alternate infiltration, continue half an hour, make the micropore of film fully be extracted infiltration mutually;

B mixes feed liquid and the volume ratio of extraction phase by 5～50:1 in the feed liquid storage tank, wherein feed liquid phase solute concentration can be between 300～2500ppm, and with peristaltic pump the feed liquid and the mixture of extraction phase being sent into film organ pipe journey inlet (4), to make it be that 0.01～0.02m/s is mobile with flow velocity hollow fiber conduit (tube side) in; With pump film device shell side inlet (6) being sent in back extraction mutually makes it be adverse current at doughnut interbank (shell side) mutually with feed liquid to pass through, flow velocity is controlled at 0.01～0.025m/s, adjustable pipe, shell side pressure difference were stablized sample analysis 15-30 minutes to prevent alternate infiltration; From the unnecessary organic facies that tube side outlet (5) is flowed out, be collected in the residual storage tank of collection, through simple clarification phase-splitting, loop back tube side inlet (4), reuse.

Wherein step B also can realize like this: with peristaltic pump the feed liquid and the mixture of extraction phase being sent into film device shell side inlet (6), to make it be that 0.01～0.025m/s is mobile with flow velocity doughnut interfascicular (shell side) in; With pump film organ pipe journey inlet (4) is sent in back extraction mutually and made it be adverse current mutually with feed liquid in hollow fiber conduit pipe (tube side) to pass through, flow velocity is controlled at 0.01～0.02m/s, and other are operated with step B; From the unnecessary organic facies that shell side outlet (7) is flowed out, be collected in the residual storage tank of collection, through simple clarification phase-splitting, loop back shell side inlet (6), reuse.

The present invention is applicable to that system consists of the process of feed liquid phase-extraction phase-back extraction phase, as NaSCN/ sulfuric acid-isopropyl ether-NaOH, and caprolactam-benzene-water, lactic acid-systems such as TBP/ kerosene-water.

At feed liquid is the aqueous solution mutually, and extraction phase is the system of organic solvent, adopts the hydrophobic type hollow-fibre membrane, and the hydrophobic type hollow-fibre membrane is selected polypropylene, Kynoar or polytetrafluoroethylene (PTFE) for use; At feed liquid is organic matter mutually, and extraction phase is the system of aqueous solvent, adopts the hydrophilic hollow-fibre membrane, and the hydrophilic hollow-fibre membrane is selected polyacrylonitrile, polysulfones, cellulose or modified polyvinilidene fluoride for use.

Mass transfer principle of the present invention can be illustrated by seeing Fig. 2 (a), when feed liquid flows in hollow fiber conduit with extraction phase, extraction phase forms very tiny droplet (9) in tube fluid, because the wellability of surface tension and film influence, the extraction phase droplet sticks on the internal face (8) of film automatically, utilize the mobile formed shearing force of phase fluid in the pipe, form one deck organic facies liquid film (10) as thin as a wafer, and organic facies liquid film (10) constantly merges and separates with extraction phase droplet (9), thereby forms new organic facies liquid film and extraction phase droplet (9); Simultaneously because the existence of film back extraction, solute is constantly by organic facies liquid film (10) with remain in organic facies (11) diffusion in the doughnut membrane micropore and arrive and manage outer back extraction liquid phase.

If feed liquid flows with the shell side of extraction phase at membrane contactor, its mass transfer principle is seen Fig. 2 (b): when feed liquid flows outside hollow fiber conduit with extraction phase, extraction phase forms very tiny droplet (14) in extratubal fluid, because the wellability of surface tension and film influence, the extraction phase droplet sticks on the outside wall surface (17) of film automatically, utilize the mobile formed shearing force of pipe external fluid phase, form one deck organic facies liquid film (15) as thin as a wafer, and organic facies liquid film (15) constantly merges and separates with extraction phase droplet (14), thereby forms new organic facies liquid film (15) and extraction phase droplet (14); Simultaneously because the existence of film back extraction, solute constantly arrives the interior back extraction liquid phase of pipe by organic facies liquid film (15) and organic facies (16) diffusion that remains in the doughnut membrane micropore.

Distinguishing feature: hollow fiber renewal liquid membrane technology of the present invention is when realizing peer's extraction back extraction, and its mass tranfer coefficient magnitude is 10 ^-6(seeing Fig. 3～8) illustrates that the mass-transfer performance of this technology has increased substantially.This is because in hollow fiber renewal liquid membrane technology, because the influence that fluid flows, film surface organic facies liquid film constantly merges and separates with the extraction phase droplet, thereby forms new organic facies liquid film and extraction phase droplet, has strengthened mass transfer; In addition, the organic facies liquid film becomes as thin as a wafer thickness of liquid film because of the effect of shearing force, thereby has solved the excessive problem of the existing liquid-film resistance of doughnut containing (sealing) liquid film technology.

Description of drawings:

Fig. 1 is the used assembly schematic diagram of hollow fiber renewal liquid membrane technology, and wherein each sequence number is represented respectively: 1. the membrane contactor of doughnut, 2. tube side flow control valve, 3. shell side flow control valve, 4. tube side inlet, 5. tube side outlet, 6. shell side enters the mouth, 7. shell side outlet.

Fig. 2 is an a certain doughnut profilograph of the used assembly of hollow fiber renewal liquid membrane technology, wherein each sequence number representative: 8,13 fiber inwalls, 9,14 extraction phase droplets, organic facies, 10,15. organic facies liquid films in 12,17. fiber outer walls, 11,16. fenestras and the hole.

Fig. 3 is the K of embodiment 1,2 used systems _f-back extraction phase flow velocity linear relationship chart.

Fig. 4 is the K of embodiment 3,4 used systems _f-feed liquid phase flow velocity linear relationship chart

Fig. 5 is the K of embodiment 5,6 used systems _f-feed liquid phase flow velocity linear relationship chart.

Fig. 6 is the K of embodiment 7,8 used systems _f-feed liquid phase flow velocity linear relationship chart.

Fig. 7 is the K of embodiment 9,10 used systems _f-back extraction phase flow velocity linear relationship chart.

Fig. 8 is the K of embodiment 11,12 used systems _f-back extraction phase flow velocity linear relationship chart.

The specific embodiment

Embodiment 1

Measuring the test system is with CuCl ₂For the feed liquid phase, be extraction phase, be the back extraction phase that the 1# film of selecting for use Tianjin Fang Mao membrane separation technique Co., Ltd to provide is used film for experiment with HCl with P204/ kerosene=1:9 (volume ratio), film and membrane module structure parameter see Table 1.Feed liquid and the volume ratio of extraction phase with 50:1 are mixed in the feed liquid storage tank, with peristaltic pump it is sent into film organ pipe journey inlet (see figure 1), flow is 3.3ml/min; With peristaltic pump film device shell side inlet is delivered in back extraction mutually equally, flow is 6ml/min, and adjustable pipe, shell side liquid level difference prevent alternate infiltration.After stablizing half an hour, record film organ pipe journey inlet Cu with Indirect Iodine Method ²⁺Concentration $x_f^{\mathrm{in}}=2465\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration $x_f^{\mathrm{out}}=2348\mathrm{ppm}$ , shell side import Cu ²⁺Concentration $x_s^{\mathrm{in}}=0\mathrm{ppm}$ With shell side outlet Cu ²⁺Concentration $x_s^{\mathrm{out}}=123\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current operation condition thus _f=1.94 * 10 ^-6M/s.

Table 1 film and membrane module structure parameter

Embodiment 2

Change embodiment 1 mesochite range of flow into 12ml/min, other conditions are constant, record film organ pipe journey inlet Cu ²⁺Concentration $x_f^{\mathrm{in}}=2465\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration $x_f^{\mathrm{out}}=2390\mathrm{ppm}$ , shell side import Cu ²⁺Concentration $x_s^{\mathrm{in}}=0\mathrm{ppm}$ With shell side outlet Cu ²⁺Concentration $x_s^{\mathrm{out}}=134\mathrm{ppm},$ Calculate contrary overall mass transfer coefficient K _f=2.11 * 10 ^-6M/s.

Embodiment 3

Tube side fluid among the embodiment 1 is changed to the mixture of back extraction and extraction phase, the volume ratio 20:1 of back extraction and extraction phase, flow is 3.3ml/min; With peristaltic pump feed liquid is delivered to film device shell side inlet mutually, flow is 25ml/min, and other conditions are constant.Record film organ pipe journey inlet Cu ²⁺Concentration $x_s^{\mathrm{in}}=32\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration $x_s^{\mathrm{out}}=396\mathrm{ppm}$ , shell side import Cu ²⁺Concentration $x_f^{\mathrm{in}}=2662\mathrm{ppm}$ With shell side outlet Cu ²⁺Concentration $x_f^{\mathrm{out}}=2592\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current operation condition _f=4.03 * 10 ^-6M/s.

Embodiment 4

Change embodiment 3 mesochite range of flow into 41ml/min, other conditions are constant.Record film organ pipe journey inlet Cu ²⁺Concentration $x_s^{\mathrm{in}}=32\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration, Cu ²⁺Concentration $x_s^{\mathrm{out}}=405\mathrm{ppm}$ , the shell side import $x_f^{\mathrm{in}}=2668\mathrm{ppm}$ Cu ²⁺Concentration and shell side outlet $x_f^{\mathrm{out}}=2606\mathrm{ppm}$ , calculate overall mass transfer coefficient K under the counter-current condition _f=5.80 * 10 ^-6M/s.

Embodiment 5

Pipe among the embodiment 1, shell-side fluid are exchanged, i.e. tube side is walked in back extraction mutually, and flow is 2.5ml/min; Feed liquid is walked shell side with the mixture of extraction phase, and flow is 9ml/min, and other conditions are constant.Record film organ pipe journey inlet Cu ²⁺Concentration $x_s^{\mathrm{in}}=168\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration $x_s^{\mathrm{out}}=349\mathrm{ppm}$ , shell side import Cu ²⁺Concentration $x_f^{\mathrm{in}}=2419\mathrm{ppm}$ With shell side outlet Cu ²⁺Concentration $x_f^{\mathrm{out}}=2338\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current condition _f=1.64 * 10 ^-6M/s.

Embodiment 6

Change the shell side flow among the embodiment 5 into 15ml/min, other conditions are constant.Record film organ pipe journey inlet Cu ²⁺Concentration $x_s^{\mathrm{in}}=168\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration $x_s^{\mathrm{out}}=336\mathrm{ppm}$ , shell side import Cu ²⁺Concentration $x_f^{\mathrm{in}}=2419\mathrm{ppm}$ With shell side outlet Cu ²⁺Concentration $x_f^{\mathrm{out}}=2325\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current condition _f=3.19 * 10 ^-6M/s.

Embodiment 7

Experiment to be measured among the embodiment 5 is changed to the 2# film that Beijing Di Ke company provides with film, and tube side back extraction phase flow rate is 2.2ml/min, and shell side feed liquid phase flow rate is 6.4ml/min,, other conditions are constant.Record film organ pipe journey inlet Cu ²⁺Concentration $x_s^{\mathrm{in}}=97\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration $x_s^{\mathrm{out}}=195\mathrm{ppm}$ , shell side import Cu ²⁺Concentration $x_f^{\mathrm{in}}=2448\mathrm{ppm}$ With shell side outlet Cu ²⁺Concentration $x_f^{\mathrm{out}}=2356\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current condition _f=1.65 * 10 ^-6M/s.

Embodiment 8

Change the shell side flow among the embodiment 7 into 10.6ml/min, other conditions are constant.Record film organ pipe journey inlet Cu ²⁺Concentration $x_s^{\mathrm{in}}=97\mathrm{ppm}$ , tube side outlet Cu ²⁺Concentration $x_s^{\mathrm{out}}=189\mathrm{ppm}$ , shell side import Cu ²⁺Concentration $x_f^{\mathrm{in}}=2448\mathrm{ppm}$ With shell side outlet Cu ²⁺Concentration $x_f^{\mathrm{out}}=2363\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current condition _f=1.9 * 10 ^-6M/s.

Embodiment 9

System among the embodiment 1 is changed to lactic acid-TBP/ kerosene-water, and the flow of tube side feed liquid and extractant mixture is 2.2ml/min, and shell side back extraction phase flow rate is 4.2ml/min, and other conditions are constant.With the methods analyst concentration of lactic acid of standard NaOH solution titration, record film organ pipe journey inlet lactic acid concn $x_f^{\mathrm{in}}=2496\mathrm{ppm}$ , tube side outlet lactic acid concn $x_f^{\mathrm{out}}=2416\mathrm{ppm}$ , shell side import lactic acid concn $x_s^{\mathrm{in}}=99\mathrm{ppm}$ With shell side outlet lactic acid concn $x_s^{\mathrm{out}}=166\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current operation condition thus _f=0.69 * 10 ^-6M/s.

Embodiment 10

Change the shell side flow among the embodiment 9 into 6.4ml/min, other conditions are constant.Record film organ pipe journey inlet lactic acid concn $x_f^{\mathrm{in}}=2496\mathrm{ppm}$ , tube side outlet lactic acid concn $x_f^{\mathrm{out}}=2416\mathrm{ppm}$ , shell side import lactic acid concn $x_s^{\mathrm{in}}=99\mathrm{ppm}$ With shell side outlet lactic acid concn $x_s^{\mathrm{out}}=199\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current operation condition thus _f=1.06 * 10 ^-6M/s.

Embodiment 11

System among the embodiment 9 is changed to caprolactam-benzene-water, and the flow of tube side feed liquid and extractant mixture is 3.3ml/min, and shell side back extraction phase flow rate is 9ml/min, and other conditions are constant.Send out the concentration that method is analyzed caprolactam with AAS, record film organ pipe journey inlet caprolactam concentration $x_f^{\mathrm{in}}=2465\mathrm{ppm}$ , tube side outlet caprolactam concentration $x_f^{\mathrm{out}}=2369\mathrm{ppm}$ , shell side import caprolactam concentration $x_s^{\mathrm{in}}=0\mathrm{ppm}$ With shell side outlet caprolactam concentration $x_s^{\mathrm{out}}=130\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current operation condition thus _f=2.02 * 10 ^-6M/s.

Embodiment 12

Change the shell side flow among the embodiment 11 into 15ml/min, other conditions are constant.Record film organ pipe journey inlet caprolactam concentration $x_f^{\mathrm{in}}=2465\mathrm{ppm}$ , tube side outlet caprolactam concentration $x_f^{\mathrm{out}}=2355\mathrm{ppm}$ , shell side import caprolactam concentration $x_s^{\mathrm{in}}=0\mathrm{ppm}$ With shell side outlet caprolactam concentration $x_s^{\mathrm{out}}=136\mathrm{ppm},$ Calculate overall mass transfer coefficient K under the counter-current operation condition thus _f=3.87 * 10 ^-6M/s.

Claims (4)

1. method of utilizing hollow fiber renewal liquid membrane technology to realize extracting-back extraction at the same level, this technology is to realize by hollow fiber film assembly, this hollow fiber film assembly is a membrane contactor that one group of hollow-fibre membrane is housed, be provided with tube side flow control valve and shell side flow control valve at two ends, the tube side inlet is arranged at two ends, the tube side outlet, shell side inlet, shell side outlet;

It is characterized in that having adopted following operating procedure:

A flows through membrane contactor with extraction phase and deionized water from tube side inlet (4) and shell side inlet (6) respectively, and adjustable pipe, shell side pressure are poor, prevent alternate infiltration, lasting half an hour, makes in the micropore of film and soaks into extraction phase in advance;

B mixes feed liquid and the volume ratio of extraction phase by 5～50:1 in the feed liquid storage tank, wherein feed liquid phase solute concentration is between 300～2500ppm, and with peristaltic pump the feed liquid and the mixture of extraction phase being sent into film organ pipe journey inlet (4), to make it be that 0.01～0.02m/s flows with flow velocity in hollow fiber conduit; With pump film device shell side inlet (6) is sent in back extraction mutually and made it be adverse current mutually with feed liquid and pass through in that doughnut is interbank, flow velocity is controlled at 0.01～0.025m/s, and adjustable pipe, shell side pressure difference were stablized sample analysis 15-30 minutes to prevent alternate infiltration; From the unnecessary organic facies that tube side outlet (5) is flowed out, be collected in the residual storage tank of collection, through simple clarification phase-splitting, loop back tube side inlet (4), reuse; Described feed liquid is the aqueous solution mutually, and extraction phase is an organic solvent, and the hollow-fibre membrane that adopts is a hydrophobic type.

2. the method for extracting-back extraction at the same level according to claim 1, it is characterized in that: the hydrophobic type hollow-fibre membrane is selected polypropylene, Kynoar or polytetrafluoroethylene (PTFE) for use.

3. the method for extracting-back extraction at the same level according to claim 1 is characterized in that this method is applicable to NaSCN/ sulfuric acid-isopropyl ether-NaOH, caprolactam-benzene-water or lactic acid-TBP/ kerosene-aqueous systems.

4. the method for extracting-back extraction at the same level according to claim 1 is characterized in that the material of step B also can flow by following mode: with peristaltic pump the feed liquid and the mixture of extraction phase being sent into film device shell side inlet (6), to make it be that 0.01～0.025m/s is mobile with flow velocity in the doughnut interfascicular; With pump film organ pipe journey inlet (4) is sent in back extraction mutually and made it be adverse current mutually with feed liquid in hollow fiber conduit to pass through, flow velocity is controlled at 0.01～0.02m/s, and adjustable pipe, shell side pressure difference were stablized sample analysis 15-30 minutes to prevent alternate infiltration; From the unnecessary organic facies that shell side outlet (7) is flowed out, be collected in the residual storage tank of collection, through simple clarification phase-splitting, loop back shell side inlet (6), reuse.

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