阅读说明：本技术 一种聚结纤维的制备方法及应用 (Preparation method and application of coalescent fiber ) 是由 杨丽 奚振宇 张建华 于 2019-08-22 设计创作，主要内容包括：本发明公开了一种聚结纤维的制备方法及由该方法制备的聚结纤维,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熔融和脱泡处理,得到纺丝液；S2.对所述纺丝液进行挤出处理；S3.对所述步骤S2得到的纺丝液进行纺丝处理,得到初生纤维；S4.使所述初生纤维在空气中暴露5-30s,使稀释剂挥发；S5.对步骤S4得到的初生纤维进行冷却处理,得到纤维长丝；S6.对步骤S5得到的纤维长丝进行萃取处理,制得所述聚结纤维。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聚结纤维孔径适中、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。(The invention discloses a preparation method of coalescent fiber and the coalescent fiber prepared by the method, which comprises the following steps: s1, melting and defoaming a mixture containing polypropylene resin and a diluent to obtain a spinning solution; s2, extruding the spinning solution; s3, spinning the spinning solution obtained in the step S2 to obtain nascent fibers; s4, exposing the nascent fiber in the air for 5-30s to volatilize the diluent; s5, cooling the nascent fiber obtained in the step S4 to obtain a fiber filament; s6, carrying out extraction treatment on the fiber filaments obtained in the step S5 to obtain the coalescent fibers. The method has simple process and short production path, and the coalescent fiber prepared by the method has moderate aperture, high mechanical strength and excellent separation performance, is applied to treating the oily sewage and has high oil removal efficiency on the sewage.)

1. A method of making a coalesced fiber comprising the steps of:

s1, melting and defoaming a mixture containing polypropylene resin and a diluent to obtain a spinning solution;

s2, spinning the spinning solution obtained in the step S1 to obtain nascent fibers;

s3, exposing the nascent fiber in the air for 5-30s to volatilize the diluent;

s4, cooling the nascent fiber obtained in the step S3 to obtain a fiber filament;

s5, extracting the fiber filaments obtained in the step S4 to obtain the coalescent fiber.

2. The production method according to claim 1, wherein the mass ratio of the polypropylene resin to the diluent is (20-90): (10-80), preferably (45-85): (15-55); and/or the diluent comprises vegetable oil and/or phthalate ester compounds.

3. The method as claimed in claim 1 or 2, 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.

4. The production method according to any one of claims 1 to 3, wherein the spinning process in step S2 includes: conveying the spinning solution to a spinning nozzle, and extruding through the spinning nozzle to obtain nascent fiber; and/or the aperture of the spinneret is 0.1-5mm, and the temperature is 140-180 ℃.

5. The production method according to any one of claims 1 to 4, wherein the step S4 includes:

and (3) cooling the fiber by staying in a water bath at 80-100 ℃ for 5-20s, cooling by staying in a water bath at 40-60 ℃ for 1-20s, and cooling by staying in a water bath at 2-10 ℃ for 1-20s to obtain the fiber filament.

6. The method of any one of claims 1-5, further comprising the steps of:

s4-1, drafting the cooled fiber filaments; preferably, the draw ratio of the draw treatment is 5 to 20.

7. The production method according to any one of claims 1 to 6, wherein the step S5 includes: putting the fiber filaments obtained in the step S4 into an extracting agent for extraction or a plurality of extracting agents for extraction, wherein the extraction time is 3-48 h; and/or the extractant is selected from a ketone, an alcohol or an alkane.

8. The method for preparing according to any one of claims 1 to 7, further comprising the steps of:

and S6, respectively soaking the coalesced fiber by using an acid solution and an alkali solution, and cleaning and drying the coalesced fiber.

9. Coalesced fiber prepared according to the method of any one of claims 1 to 8, having a diameter of 0.1 to 5mm and a specific surface area of 18.5 to 28.9m²/g。

10. Use of a coalescent fiber prepared according to any one of claims 1 to 8 or the coalescent fiber of claim 9 for treating oily wastewater comprising passing oily wastewater through the coalescent fiber to separate an oil phase and an aqueous phase therein.

11. 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 coalesced fiber prepared according to the method of any one of claims 1 to 8 or the coalesced fiber of claim 9 for receiving the oily wastewater from the liquid tank and treating the same to separate oil phase and 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 coalescent fiber, a coalescent fiber material prepared by the method, application of the coalescent 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 coalescent fiber with pores formed on the surface according to the defects in the prior art, the method has simple and convenient process and short production path, and the coalescent fiber prepared by the method has moderate aperture, high surface roughness, large specific surface area, high mechanical strength and excellent separation performance, is applied to treating oily sewage, and has high oil removal efficiency on the sewage.

According to one aspect of the present invention, there is provided a method for preparing surface-porogenic coalesced fibers, comprising the steps of:

s1, melting and defoaming a mixture containing polypropylene resin and a diluent to obtain a spinning solution;

s2, spinning the spinning solution obtained in the step S1 to obtain nascent fibers;

s3, exposing the nascent fiber in the air for 5-30s to volatilize the diluent;

s4, cooling the nascent fiber obtained in the step S3 to obtain a fiber filament;

s5, extracting the fiber filaments obtained in the step S4 to obtain the coalescent fiber.

According to a preferred embodiment of the present invention, the mass ratio of the polypropylene resin to the diluent is (20-90) to (10-80), preferably (45-85) to (15-55).

Within the mass ratio range, the prepared fiber has good mechanical property and uniform surface pore distribution.

According to a preferred embodiment of the present invention, the polypropylene resin has a melt index of 0.2-80g/10min, and the polypropylene resin has good flowability, processability and mechanical properties in the melt index range, wherein the melt index test condition is that the temperature is 230 ℃ and the load weight is 2.16 kg.

According to a preferred embodiment of the invention, the diluent comprises vegetable oil and/or phthalate type compounds.

According to a particular embodiment of the invention, the vegetable oil is selected from at least one of peanut oil, castor oil and soybean oil, preferably soybean oil.

According to a specific embodiment of the present invention, the phthalate-based compound includes at least one of dibutyl phthalate, diamyl 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 0.5-3 h.

According to a preferred embodiment of the present invention, the step S1 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 steps S2 and S3 may be performed as follows: and filtering the spinning solution, conveying the filtered spinning solution to a spinning nozzle by using a metering pump, extruding the spinning solution at a constant speed through the spinning nozzle to obtain fiber filaments, and exposing the fiber filaments in the air for 5-30 seconds to volatilize the diluent.

According to some embodiments of the invention, the step S4 includes:

and (2) allowing the polypropylene filaments to stay for 5-20s through a water bath at 80-100 ℃ for cooling, allowing the polypropylene filaments to stay for 1-20s through a water bath at 40-60 ℃ for cooling, and allowing the polypropylene filaments to stay for 1-20s through a water bath at 2-10 ℃ for cooling, and solidifying to obtain the fiber filaments.

According to the invention, as-spun fibers are cooled and solidified by three different coagulation baths, the internal stress of the fibers can be reduced to the greatest extent, the phenomena of stress cracking, buckling deformation and the like are prevented, and the mechanical and thermal properties of the fibers are improved.

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

and S4-1, drawing the cooled fiber filament.

According to a preferred embodiment of the invention, the draw ratio of the draw treatment is 5 to 20.

According to some embodiments of the invention, the step S5 includes: and (4) putting the fiber filaments obtained in the step S4 into an extracting agent for extraction or a plurality of extracting agents for extraction.

According to a preferred embodiment of the invention, the extraction time is between 3 and 48 h.

According to a preferred embodiment of the present invention, the extractant is selected from at least one of a ketone, an alcohol and an alkane.

According to a specific embodiment of the present invention, the ketone comprises acetone.

According to a specific embodiment of the present invention, the alcohol comprises at least one of methanol, ethanol and isopropanol.

According to a particular embodiment of the invention, the alkane comprises n-hexane and/or cyclohexane.

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

and S6, respectively soaking the coalesced fiber by using an acid solution and an alkali solution, and cleaning and drying the coalesced 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 S6 may be performed as follows: soaking the prepared coalesced 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 60-80 ℃ for 12-24h, and removing the moisture on the surface to obtain the coalesced fiber.

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

According to another aspect of the present invention, there is also provided a surface-porogenic agglomerated fiber prepared according to the above method, having a diameter of 0.1 to 5mm and a specific surface area of 18.5 to 28.9m²/g。

According to another aspect of the present invention there is also provided the use of the above-described coalesced fibres for treating oily sewage, comprising passing the oily sewage through the coalesced fibres to separate the oil and water phases therein.

The coalescence fiber with pores formed on the surface is an oleophilic material, when oily sewage passes through the coalescence fiber, oil drops in the sewage are coalesced on the surface of the coalescence fiber due to different affinities of oil phase and water phase to the coalescence fiber, so that the oil drops are enlarged from small to large, the enlarged oil drops 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 packed with said coalescing fibers for receiving oily wastewater from said tank and treating the same 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 coalesced fibers are packed into the 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, pumping liquid in the sewage tank into a coalescer through a feeding pump, and controlling the inflow of water to be 0.1-0.5m by adjusting a flow regulating valve³Within/h; the oil phase in the sewage is slowly attached to the surface of the coalesced fiber and then is gathered to form oil drops, the large-particle oil drops are carried away from the surface of the coalesced 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 sewage is preferably 30-50 ℃.

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

(1) the coalescent fibers are packed into the bed layer of the coalescer in a layered compaction mode, wherein 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 coalesced fiber and then is gathered to form oil drops, the large oil drops are carried away from the surface of the coalesced fiber by the water phase and enter an oil collecting tank through an oil phase outlet, and the water without the oil phaseThe phases enter the water production tank via the aqueous phase outlet.

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

(1) the invention prepares the coalescence fiber with pore-forming on the surface by a thermally induced phase separation method, and the preparation process is simple and easy to operate;

(2) the main raw material polypropylene has rich sources, easily controlled specification indexes, low price, excellent chemical reagent resistance and higher mechanical strength, so that the prepared coalescent fiber has reliable quality; the pore-forming organic solvent is environment-friendly, non-toxic or low-toxic, the extracting agent is an industrial conventional reagent, and the coagulating bath is simple, convenient and easily-obtained non-solvent deionized water, so that the production cost in the whole process is greatly reduced;

(3) after the spinning solution melt is extruded, the air atmosphere is utilized, and the air acts as a diluent volatilization place, so that the pore forming on the surface of the nascent fiber is facilitated; the fiber is drafted in a proper proportion in the process of fiber solidification, so that a large number of micropores are formed on the outer surface of the fiber;

(4) the generated nascent fiber is slowly cooled at three different solidification bath temperatures in the solidification process, so that the internal stress of the fiber is reduced to the maximum extent, the phenomena of stress cracking, buckling deformation and the like are prevented, and the mechanical and thermal properties of the polypropylene fiber coalescence material are improved;

(5) the oil-water separation equipment filled with the coalesced fiber has compact structure, full sealing, safety and explosion prevention, realizes the device treatment of oily sewage, has high treatment efficiency, can recycle the recovered dirty oil as resources, 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 coalesced fiber of the 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 coalescing 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 21 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 a 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 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 nascent fibers, exposing the nascent fibers in air for a period of time to volatilize a diluent, cooling by a three-stage water bath, drafting after solidification, winding by a traction wheel to collect porous fiber filaments, and putting the filaments into an extracting agent for extraction.

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

The data of each step are shown in Table 1.

TABLE 1

Examples 22 to 46 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 8.0, and the oil content is 1529 mg/L.

(1) The coalesced fibers prepared in examples 1 to 21 and comparative examples 1 to 11 were packed in layers in the bed of the coalescer 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.