阅读说明：本技术 一种多孔纤维的制备方法及应用 (Preparation method and application of porous fiber ) 是由 杨丽 魏昕 侯秀华 于 2019-08-22 设计创作，主要内容包括：本发明公开了一种多孔纤维的制备方法及由该方法制备的多孔纤维,包括以下步骤：S1.对包含聚丙烯树脂和稀释剂的混合物进行纺丝处理,得到初生纤维；S2.使所述初生纤维经过冷却处理,得到纤维长丝；S3.对所述纤维长丝进行萃取处理,得到所述多孔纤维。本发明方法工艺简便,生产路径短,根据本发明的方法制备的多孔纤维孔径适中、表面积大、表面粗糙度高、机械强度高、分离性能优良,应用于处理含油污水中,对污水的除油效率高,本发明还提供了一种处理含油污水的装置,结构简单,消耗动力少,无需投加任何药剂,就能对污水中的油污起到较好的去除效果,且污染较低,在含油污水处理领域具有良好的应用前景。(The invention discloses a preparation method of porous fiber and the porous fiber prepared by the method, comprising the following steps: s1, spinning a mixture containing polypropylene resin and a diluent to obtain nascent fibers; s2, cooling the nascent fiber to obtain a fiber filament; and S3, extracting the fiber filaments to obtain the porous fiber. The method has simple and convenient process and short production path, and the porous fiber prepared by the method has moderate aperture, large surface area, high surface roughness, high mechanical strength and excellent separation performance, is applied to treating the oily sewage, has high oil removal efficiency on the sewage, has simple structure and low power consumption, can play a good role in removing the oil stain in the sewage without adding any medicament, has low pollution and has good application prospect in the field of oily sewage treatment.)

1. A method of making porous fibers comprising the steps of:

s1, spinning a mixture containing polypropylene resin and a diluent to obtain nascent fibers;

s2, cooling the nascent fiber to obtain a fiber filament;

and S3, extracting the fiber filaments to obtain the porous fiber.

2. The method for preparing a composite material according to claim 1, wherein the step S1 includes:

1A, melting and defoaming a mixture containing polypropylene resin and a diluent to obtain a spinning solution;

and 1B, conveying the spinning solution to a spinning nozzle, and extruding through the spinning nozzle to obtain nascent fibers.

3. The production method according to claim 1 or 2, characterized in that the polypropylene resin accounts for 20 to 95 mass% of the mixture, and the balance is a diluent.

4. The method according to any one of claims 1 to 3, wherein the temperature of the melting treatment is 175-230 ℃ and the time is 0.5-3 h; the time of the defoaming treatment is 0.5-3 h.

5. The production method as claimed in any one of claims 1 to 4, wherein the spinneret has a hole diameter of 0.1 to 5mm and a temperature of 140 ℃ to 180 ℃.

6. The production method according to any one of claims 1 to 5, wherein the as-spun fiber is subjected to a cooling treatment in at least two stages of coagulation baths in step S2; preferably, the as-spun fiber is first cooled through a primary coagulation bath at 60-90 ℃ and then through a secondary coagulation bath at 0-30 ℃ to produce the fiber filament.

7. The production method according to any one of claims 1 to 6, wherein the medium of the primary coagulation bath is a diluent having a mass concentration of 0 to 100%; and/or the medium of the secondary coagulation bath is deionized water.

8. The production method according to any one of claims 1 to 7, wherein the step S3 includes: placing the fiber filament into an extracting agent for extraction or placing the fiber filament into a plurality of extracting agents for sequential extraction; and/or the total extraction time is 3-48 h.

9. The method of any one of claims 1-8, wherein the extractant comprises at least one of a ketone, an alcohol, and an alkane, preferably at least one of acetone, methanol, isopropanol, n-hexane, and cyclohexane.

10. The porous fiber for oil-water separation prepared by the method according to any one of claims 1 to 9, having a diameter of 0.1 to 5mm and a specific surface area of 19.1 to 27.8m²/g。

11. Use of a porous fibre produced according to the process of any one of claims 1 to 9 or a porous fibre according to claim 10 in the treatment of oily wastewater comprising passing the oily wastewater through the porous fibre and separating the oil and water phases therein.

12. An apparatus for treating oily sewage, comprising:

a liquid storage tank for storing oily sewage;

a coalescer connected to the liquid tank and filled with the porous fiber prepared by the method according to any one of claims 1 to 9 or the porous fiber of claim 10 for receiving the oily wastewater from the liquid tank and treating the same to separate an oil phase and a water phase therein;

a water production tank connected to said coalescer for receiving the aqueous phase from said coalescer;

an oil collection tank connected to the coalescer for receiving the oil phase from the coalescer.

Technical Field

The invention relates to a preparation method of porous fiber, a porous fiber material prepared by the method, application of the porous fiber material in treating oily sewage, and a device for treating oily sewage, belonging to the technical field of water treatment.

Background

Oil pollution, a common pollution, is extremely harmful to environmental protection and ecological balance. The range of producing the oily sewage is wide, and the oily sewage is produced in the processes of petroleum exploitation, petroleum refining, petrochemical industry, oil storage and transportation and the like. The oil-containing sewage in China has extremely high yield, more than 30 hundred million tons of oil-containing sewage are generated every year in oil fields and oil refining industries, the oil-containing sewage is one of the industrial waste water which is difficult to treat at present, and along with the requirement on environmental protection and the gradual strictness of energy conservation and consumption reduction, the oil concentration of the discharged sewage specified in the comprehensive sewage discharge standard (GB 8978-.

The coalescence-separation method is a physical oil-removing method, integrates gravity separation and coalescence technologies, and utilizes the characteristic of oil-water density difference to realize the separation process. The coalescence separator has the advantages of low power consumption, high separation efficiency, large operation elasticity and the like, when oily sewage passes through the coalescence separator, oil drops interact with the coalescence material, due to lipophilicity of the surface of the material, the oil drops and the surface of the material form a continuous oil film with a certain thickness, when subsequent oil drops pass through the surface, a liquid-sandwiched layer is formed between the oil drops and the film, the liquid film of the liquid drops is gradually deformed and thinned in the liquid discharging process, the liquid film is broken when reaching a critical value, the two liquid drops are fused and grow up, the small oil drops are gradually aggregated into large oil drops, and along with the traction force of water flow, the large oil drops break away from the adsorption of the coalescence material to realize falling and enter an oil layer under the action of buoyancy to. The technical key of the coalescence method for removing oil is a coalescence material which can be divided into a porous material, a fiber material, a granular material and the like, wherein the fiber material can be made into a material with a smaller diameter and a larger surface area, and the coalescence material has obvious oil removing effect. The surface structure characteristics can have a large influence on the coalescence-separation effect in terms of the properties of the coalesced fiber material itself.

Disclosure of Invention

The invention aims to provide a preparation method of porous fiber according to the defects in the prior art, the method has simple and convenient process and short production path, the porous fiber prepared by the method has moderate aperture, large surface area, high surface roughness, high mechanical strength and excellent separation performance, is applied to the treatment of the sewage containing oil, and has high oil removal efficiency on the sewage.

According to an aspect of the present invention, there is provided a method of preparing porous fiber, comprising the steps of:

s1, spinning a mixture containing polypropylene resin and a diluent to obtain nascent fibers;

s2, cooling the nascent fiber to obtain a fiber filament;

and S3, extracting the fiber filaments to obtain the porous fiber.

According to some embodiments of the invention, the step S1 includes:

1A, melting and defoaming a mixture containing polypropylene resin and a diluent to obtain a spinning solution;

and 1B, conveying the spinning solution to a spinning nozzle, and extruding through the spinning nozzle to obtain polypropylene filaments.

According to a preferred embodiment of the present invention, the polypropylene resin is 20 to 95% by mass, preferably 45 to 85% by mass, and the balance is a diluent in the mixture.

According to a preferred embodiment of the present invention, the polypropylene resin has a melt index of 0.1-100g/10min, and the polypropylene resin has good flowability, processability and mechanical properties in the melt index range, wherein the melt index is measured at a temperature of 230 ℃ and a load weight of 2.16 kg.

According to a preferred embodiment of the present invention, the diluent comprises at least one of vegetable oil and phthalate ester compound.

According to a preferred embodiment of the present invention, the vegetable oil comprises at least one of peanut oil, castor oil and soybean oil, preferably soybean oil.

According to a preferred embodiment of the present invention, the phthalate-based compound includes at least one of dibutyl phthalate, dipentyl phthalate, diheptyl phthalate, and dioctyl phthalate, preferably dibutyl phthalate and/or dioctyl phthalate.

According to a preferred embodiment of the present invention, the polypropylene resin raw material is dried at 70 to 90 ℃ for 2 to 6 hours before use, and then mixed with a diluent, preferably under nitrogen gas.

According to the preferred embodiment of the invention, the temperature of the melting treatment is 175-230 ℃, and the time is 0.5-3 h; the time of the defoaming treatment is 0.5-2 h.

According to a preferred embodiment of the present invention, the step 1A may be performed as follows: drying the polypropylene resin raw material at 70-90 ℃ for 2-6 hours, mixing the polypropylene resin raw material with a diluent in a spinning kettle with a stirring device, heating to 175-230 ℃, and stirring for 0.5-3 hours under the condition of introducing nitrogen, and uniformly mixing; and after stirring is stopped, standing and defoaming for 0.5-3h to obtain the spinning solution.

According to some embodiments of the invention, the spinneret has an aperture of 0.1 to 5mm and a temperature of 140 ℃.

According to a preferred embodiment of the present invention, the step 1B may be performed as follows: and filtering the spinning solution, conveying the filtered spinning solution to a spinning nozzle by using a metering pump, and extruding the spinning solution through the spinning nozzle at a constant speed to obtain polypropylene filaments.

According to some embodiments of the invention, the primary fiber is subjected to a cooling treatment in at least two stages of coagulation baths in the step S2; preferably, the as-spun fiber is first cooled through a primary coagulation bath at 60-90 ℃ and then through a secondary coagulation bath at 0-30 ℃ to produce the fiber filament.

According to the invention, the nascent fiber is cooled and solidified by the two stages of different coagulating baths, so that the internal stress of the fiber can be reduced to the greatest extent, the phenomena of stress cracking, warping deformation and the like are prevented, and the mechanical and thermal properties of the porous fiber are improved.

According to some embodiments of the invention, the step S3 includes: placing the fiber filament into an extracting agent for extraction or placing the fiber filament into a plurality of extracting agents for sequential extraction; and/or the total extraction time is 3-48 h.

According to a preferred embodiment of the present invention, the extractant comprises at least one of a ketone, an alcohol and an alkane, preferably at least one of acetone, methanol, isopropanol, n-hexane and cyclohexane.

According to some embodiments of the invention, the method further comprises the steps of:

and S3, respectively soaking the porous fiber with an acid solution and an alkali solution, and cleaning and drying the porous fiber.

According to a preferred embodiment of the invention, the acid solution is a hydrochloric acid solution, with a concentration of 0.5 to 1mol/L, preferably 0.5 mol/L; the alkali solution is sodium hydroxide solution, and the concentration is 0.5-1mol/L, preferably 0.5 mol/L.

According to a preferred embodiment of the present invention, the step S3 may be performed as follows: soaking the prepared porous fiber in an acid solution for 5-10h, then soaking in an alkali solution for 5-10h, washing with deionized water to neutrality, then drying at 70-90 ℃ for 12-24h, and removing surface moisture to obtain the porous fiber.

After the treatment, the pollutants on the surface of the fiber can be removed.

The polypropylene is mixed with the diluent with high boiling point and low volatility to form homogeneous solution at high temperature, the homogeneous solution is cooled after being prepared into fiber shape, the fiber is subjected to phase separation, the diluent is removed by solvent extraction, and then more pore channel structures are formed on the surface of the fiber, so that the specific surface area and the roughness of the fiber are increased, and the affinity and the adsorption capacity to oil stains are improved.

According to another aspect of the present invention, there is also provided a porous fiber having a diameter of 0.1 to 5mm and a specific surface area of 19.1 to 27.8m, prepared according to the above method²/g。

According to another aspect of the present invention, there is also provided the use of the above porous fibre in the treatment of oily wastewater, comprising passing the oily wastewater through the porous fibre to separate the oil and water phases therein.

The porous fiber is an oleophilic material, when oily sewage passes through the porous fiber, oil drops in the sewage are coalesced on the surface of the porous fiber due to different affinities of an oil phase and a water phase to the fiber, so that the oil drops are changed from small to large, the oil drops after being changed in size float upwards due to smaller density, and further the oil phase and the water phase are separated.

According to another aspect of the present invention, there is also provided an apparatus for treating oily sewage, comprising:

a liquid storage tank for storing oily sewage;

a coalescer connected to said tank and filled with said porous fiber for receiving and treating oily wastewater from said tank to separate oil and water phases therein;

a water production tank connected to said coalescer for receiving the aqueous phase from said coalescer;

an oil collection tank connected to the coalescer for receiving the oil phase from the coalescer.

According to some embodiments of the invention, the porous fibers are packed in a bed of the coalescer by layered compaction at a packing ratio of 1/2.

According to a preferred embodiment of the present invention, the coalescer is provided with a sewage inlet, a water phase outlet and an oil phase outlet. In some specific embodiments, the oil phase outlet is disposed in an upper portion of the coalescer, and the water phase outlet is disposed in a sidewall of the coalescer.

According to a preferred embodiment of the invention, the apparatus further comprises a sewage tank arranged between the liquid reservoir and the coalescer, the sewage tank being provided with a sewage inlet communicating with the liquid reservoir via a pipe, a sewage outlet communicating with the inlet of the coalescer via a pipe, and a gas inlet, for receiving sewage from the liquid reservoir and conveying it to the coalescer.

According to a preferred embodiment of the present invention, the apparatus further comprises a sewage pump disposed on the pipe between the liquid tank and the sewage tank, for pumping the sewage in the liquid tank into the sewage tank.

According to a preferred embodiment of the invention, the apparatus further comprises a gas source connected to the gas inlet of the waste tank for supplying gas into the waste tank to propel waste into the coalescer. In some embodiments, the gas source is a nitrogen gas cylinder. The air source is connected with the sewage tank through a pipeline, and a pressure stabilizing valve is arranged on the pipeline.

According to a preferred embodiment of the present invention, the apparatus further comprises a flow regulating valve, a flow meter and a feed pump arranged in sequence on the pipe between the sewage tank and the coalescer.

According to a preferred embodiment of the invention, the water production tank communicates with the water phase outlet of the coalescer by means of a conduit, and the oil collection tank communicates with the oil phase outlet of the coalescer by means of a conduit.

The working process and the principle of the device for treating the oily sewage are as follows:

pumping oily sewage in a liquid storage tank into a sewage tank through a sewage pump, and then pumping the sewage into the sewage tank through a feeding pumpThe liquid in the tank is pumped into the coalescer, and the water inlet flow is controlled to be 0.1-0.5m by adjusting the flow control valve³Within/h; the oil phase in the sewage is slowly attached to the surface of the porous fiber and then is gathered to form oil drops, the large-particle oil drops are carried away from the surface of the porous fiber by the water phase and enter the oil collecting tank through the oil phase outlet, and the water phase without the oil phase enters the water producing tank through the water phase outlet.

According to another aspect of the present invention, there is provided a method for treating oily sewage using the above apparatus, comprising:

(1) the porous fibers are packed into a bed layer of a coalescer in a layered compaction mode, and the packing ratio is 1/2;

(2) pumping the oily sewage in the liquid storage tank into a sewage tank through a sewage pump;

(3) opening a flow regulating valve, a flowmeter, a pressure stabilizing valve and an air source, pumping the liquid in the sewage tank into the coalescer by a feed pump, and controlling the inflow of water to be 0.1-0.5m by regulating the flow regulating valve³Within/h; the oil phase in the sewage is slowly attached to the surface of the porous fiber and then is gathered to form oil drops, the large-particle oil drops are carried away from the surface of the porous fiber by the water phase and enter the oil collecting tank through the oil phase outlet, and the water phase without the oil phase enters the water producing tank through the water phase outlet.

The temperature of the oily sewage is preferably controlled within the range of 30-50 ℃, so that the oil phase can be prevented from being adhered to the surface of the fiber and not easy to fall off, demulsification is facilitated, the energy consumption is increased due to high temperature, but the oil removal effect is not greatly improved, so that the method is not preferred.

The invention has the advantages and beneficial technical effects as follows:

the invention adopts the environment-friendly nontoxic or low-toxic solidification medium by a simple process, exchanges with a diluent when the fiber is formed, avoids the formation of a compact skin layer, enables the surface of the fiber to have a large amount of uniform micropore structures, increases the roughness and the surface area of the surface structure of the polypropylene fiber, is beneficial to the capture of oil drops by the material and the convergence and combination on the surface, and can greatly reduce the internal stress of the fiber after being cooled by two-stage solidification baths with different temperatures, improve the performances of the polypropylene fiber coalescence material such as mechanics, thermal property, oil-water separation and the like, overcome the problems of easy breakage, short service life and the like caused by low tensile strength of the fiber, improve the coalescence and oil-water separation efficiency, and the pore-forming method has convenient operation.

The polypropylene coalescent fiber material prepared by the invention has low price, excellent chemical reagent resistance and higher mechanical strength, the filled and prepared oil-water separation equipment has compact structure, is totally closed, safe and explosion-proof, realizes the device treatment of oily sewage, has high treatment efficiency, can recycle the recovered dirty oil, does not generate any waste residue, and does not cause secondary pollution.

Drawings

FIG. 1 is a schematic structural view of an apparatus for treating oily sewage according to the present invention;

FIG. 2 is a surface SEM image of a porous fiber of the present invention;

description of reference numerals: 1: a gas source; 2: a liquid storage tank; 3: a pressure maintaining valve; 4: a sewage pump; 5: a sewage tank; 6: a flow regulating valve; 7: a flow meter; 8: a feed pump; 9: a coalescer; 10: a water producing tank; 11: an oil collecting tank.

Detailed Description

The present invention is described below with reference to specific examples, which are not intended to limit the scope of the present invention, and those skilled in the art may make insubstantial modifications and adaptations of the present invention based on the above-described disclosure.

The starting materials used in the examples are all commercially available unless otherwise specified.

The test method comprises the following steps:

the specific surface area of the prepared fiber material is measured according to national standard GB/T19587-.

The fiber mechanical properties were tested using a 3342 universal materials tester, INSTRON USA.

The oil content in the water is measured according to the national standard GB/T16488 and 1996 determination of water quality petroleum and animal and vegetable oil;

the oil removal rate was calculated as follows:

in the formula, C₀Represents the oil content of the oily sewage in the sewage tank, mg/L;

c represents the oil content of the water phase in the water production tank, mg/L.

As shown in fig. 1, the apparatus for treating oily sewage of the present invention comprises an air source 1, a liquid storage tank 2, a pressure-stabilizing valve 3, a sewage pump 4, a sewage tank 5, a flow rate regulating valve 6, a flow meter 7, a feed pump 8, a coalescer 9, a water production tank 10 and a oil collection tank 11.

Wherein, the liquid storage tank 2 is used for storing oily sewage, the temperature of the sewage is 30-50 ℃, and the sewage is sequentially connected with a sewage pump 4 through a pipeline; the sewage pump 4 is connected with a sewage inlet of the sewage tank 5 through a pipeline and is used for pumping the oily sewage in the liquid storage tank 2 into the sewage tank 5. The gas source 1 is connected with a gas inlet of a sewage tank 5 through a pipeline, a pressure stabilizing valve 3 is arranged on the pipeline, and in the embodiment of the invention, the gas source 1 is preferably a nitrogen cylinder. The sewage outlet of the sewage tank 5 is connected with a feed pump 8 through a pipeline, a flow regulating valve 6 and a flow meter 7 are sequentially arranged on the pipeline, and the feed pump is connected with the inlet of a coalescer 9 through a pipeline and is used for pumping the sewage in the sewage tank 5 into the coalescer 9 for treatment. The coalescer 9 is filled with porous fibers to treat the wastewater and separate the oil phase from the water phase. The coalescer comprises an oil phase outlet and a water phase outlet, the oil phase outlet is connected with the oil collecting tank 11 through a pipeline, and the water phase outlet is connected with the water producing tank 10 through a pipeline.

Examples 1 to 22 and comparative examples 1 to 11

(1) And (3) drying the polypropylene master batch, adding the polypropylene master batch into a spinning kettle with a stirring device, mixing the polypropylene master batch with the diluent in proportion, heating the mixture to a certain temperature for melting, stirring the mixture for a period of time under the condition of introducing nitrogen, stopping stirring, standing the mixture for a period of time, and defoaming the mixture to obtain the polypropylene spinning solution.

(2) Filtering the spinning solution by a filter screen, conveying the spinning solution to a spinning nozzle by a metering pump, extruding the spinning solution melt at a constant speed to form porous fiber filaments, cooling and solidifying the filaments by a secondary coagulating bath, winding and collecting the porous fiber filaments by a traction wheel, and putting the filaments into an extracting agent for extraction.

(3) The prepared porous fiber is soaked in 0.5mol/L HCI solution for a period of time, then soaked in 0.5mol/L NaOH solution for a period of time, washed to be neutral by deionized water, dried in an oven, and the water adsorbed on the surface is removed, thus preparing the polypropylene porous coalescence fiber.

The data of each step are shown in Table 1.

TABLE 1

Examples 23 to 48 and comparative examples 12 to 23

The device shown in figure 1 is adopted to treat oily wastewater of a certain refinery, the pH of the wastewater is 7.8, and the oil content is 1127 mg/L.

(1) The porous fibers prepared in examples 1 to 22 and comparative examples 1 to 11 were packed in layers in a coalescer bed at a packing ratio of 1/2;

(2) pumping the oily sewage with the temperature of 30-50 ℃ in the liquid storage tank into a sewage tank through a sewage pump;

(3) opening a flow regulating valve, a flowmeter, a pressure stabilizing valve and an air source, pumping the liquid in the sewage tank into the coalescer by a feed pump, and controlling the inflow of water to be 0.1-0.5m by regulating the flow regulating valve³/h。

And measuring data after the operation is stable, and calculating to obtain the oil removal rate.

The data for each example and comparative example are shown in table 2.

TABLE 2

Any numerical value mentioned in this specification, if there is only a two unit interval between any lowest value and any highest value, includes all values from the lowest value to the highest value incremented by one unit at a time. For example, if it is stated that the amount of a component, or a value of a process variable such as temperature, pressure, time, etc., is 50 to 90, it is meant in this specification that values of 51 to 89, 52 to 88. For non-integer values, units of 0.1, 0.01, 0.001, or 0.0001 may be considered as appropriate. These are only some specifically named examples. In a similar manner, all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be disclosed in this application.

It should be noted that the above-mentioned embodiments are only for explaining the present invention, and do not constitute any limitation to the present invention. The present invention has been described with reference to exemplary embodiments, but the words which have been used herein are words of description and illustration, rather than words of limitation. The invention can be modified, as prescribed, within the scope of the claims and without departing from the scope and spirit of the invention. Although the invention has been described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, but rather extends to all other methods and applications having the same functionality.