RU2361661C2 - Sorbent material, method for its production and use - Google Patents

Abstract

FIELD: textile, paper.

SUBSTANCE: invention relates to cleaning of water from oil and oil products and also the dispersal of weak concentrations of oil emissions in water. The proposed sorbent material has a layer in the form of a volumetric, corrugated surface, and a layer of super thin fibers possessing a dielectric permeability, exceeding no less than 1.45 units, the layer from polymeric fibers with a corrugated surface. The method suggested for attaining the material consists of creating a layer of substratum from corrugated, polymeric fibers, its thermo-mechanical compaction, the creation from this of a volumetric, corrugated cloth with further thermal fixation for the formation of a layer from hydropholic, super thin fibers, laid over the above mentioned layers and affixed and supported in an electrolyte solution. The material thus acquired is used for the distribution of emulsions by filtration through sorbent material, initially through the hydrophobic surface and then through the hydrophilic layer, with the creation on the surface area of the layer of a double, electric layer.

EFFECT: increased effectiveness of cleaning processes and separation.

5 cl, 1 dwg, 2 ex, 2 tbl

Description

The invention relates to the field of water purification from emulsified particles of oil and oil products, as well as to the field of separation of stable water-oil emulsions using coalescing filter materials and to methods for manufacturing such materials.

Known sorbent material for removing oil contaminants from water, including the outer layers of polypropylene fibers and an intermediate layer of polypropylene or polyester fibers bonded by needle piercing, and the density of the outer layers is higher than the density of the intermediate layer (RU 2139959, 10.20.1999).

Known filtering and sorbing material for cleaning from petroleum products and for cleaning the petroleum products themselves, i.e. for the separation of emulsions made of inorganic and / or organic fibers in the form of single-layer or multilayer elements (V.P. Kovalenko, V.E. Turchaninov. Purification of oil products from pollution. M: Nedra, 1990, p.105. p.125 )

The closest in technical essence and the achieved result is a sorbent material for removing oil and oil products, as well as for the separation of emulsions, made in the form of a non-woven fabric of hydrophobic and / or hydrophobized polymer fibers bonded to each other, having a bulk density of 0.01-0, 06 g / cm ³ and having a corrugated structure, as well as a method for its manufacture, which consists in forming a canvas from a polymeric fibrous substrate, its compaction and corrugation (RU 2166362, 05/10/2001).

A disadvantage of the known material is the low degree of purification of water from fine particles of oil products when it is used to separate super-stable water-oil emulsions.

There is a method of separation of stable water-oil emulsions, which consists in filtering through various packages of materials containing materials with both hydrophobic and hydrophilic properties (Kovalenko V.P. Purification of oil pollution products. M .: Nedra, 1990).

The closest is a method of separating water-oil emulsions by filtering through a sorbent material, and first, selective filtration is carried out on a porous-cellular metal or alloy with hydrophobic properties, and then filtering is continued to achieve coalescence of fine droplets - on a hydrophilic material, which is used as a porous-cellular metal with modified properties, or bulk mesh of celluloid, or cassettes with glass balls (RU 2120323, 10.20.1998).

The disadvantage of this method is its low efficiency in the separation of superstable emulsions.

The objective of the present invention is to develop a composite filter material with sorbing and coalescing properties, as well as a high capacity for hydrocarbons, which allows to effectively purify water from emulsified oil products to the MPC level, which does not require laborious and energy-intensive regeneration.

In addition, the object of the invention is to develop a method for producing a highly effective composite filtering material and separation of stable water-oil emulsions using a patented material.

The problem is solved by the described sorbent material for removing oil and oil products from aqueous solutions and separation of stable oil-water emulsions containing a layer in the form of a body-corrugated non-woven fabric of polymer fibers with a hydrophobic surface and a hydrophilic superthin fiber having a dielectric constant of at least 1, 45 units exceeding the dielectric constant of a layer of polymer fibers with a hydrophobic surface. As a hydrophilic superthin fiber, it is preferable to use glass, basalt or metal fibers with a diameter of 1-15 microns or a combination thereof.

The mass ratio of the layer of polymer fibers with a hydrophobic surface and the layer of hydrophilic superthin fiber is (2-10): 1.

The problem is also solved by the described method for the manufacture of sorbent material for removing oil and oil products from aqueous solutions and separation of stable oil-water emulsions, which is described above.

The method includes the formation of a layer of a substrate of hydrophobic polymer fibers, its thermomechanical compaction, the formation of a bulk corrugated fabric from it with heat setting at a temperature of 90-120 ° C, the formation of a layer of hydrophilic superthin fiber, the application of these layers to each other, their bonding and keeping in solution electrolyte for 1-2 hours.

The problem is also solved by the described method of separation of stable water-oil emulsions, including filtering the emulsion through a sorbent material described above and containing layers of materials with hydrophobic and hydrophilic surfaces, while filtering is carried out first through a hydrophobic layer with a lower dielectric constant, and then through a hydrophilic layer with a higher dielectric constant, with the formation on the interface of the said layers of a double electric layer, a neutr lysing a double electric layer on the surface of emulsified particles.

The highest efficiency in terms of coalescing properties was shown by such combinations of materials as superthin basalt fiber with a thickness of 1-4 microns in combination with polypropylene and polyester fibers, as well as a layered composition of superthin basalt fiber and glass fiber with a thickness of 10-15 microns also in combination with polypropylene and polyester fibers.

50% basalt consists of SiO ₂ , has high electrical insulation properties. Dielectric constant value:

basalt 3.75 glass 5-16 (depending on type) polypropylene 2,3

Upon contact with water, the oxide cleavage surface is hydrated, broken chemical bonds are saturated due to OH groups. When the dehydrated surface of SiO ₂ comes into contact with water, in addition to reversible adsorption, slow surface hydration proceeds, leading to the restoration of the hydration cover participating in the formation of the double electric layer.

The drawing shows a diagram of a double electric layer in the process of separation of the emulsion, where

1 - a double electric layer formed on the interface between two materials with different dielectric constants, 2 - coalesced particles of emulsified oil, 3 - emulsified oil particle coated with a double electric layer.

The technical result, which consists in the high efficiency of the claimed material, according to the applicant, can be explained as follows.

With the close contact of two bodies with different electrochemical characteristics immersed in an aqueous medium, as a result of adsorption of dipole water molecules, which are oriented in a certain way on the interface of two materials, a corresponding potential jump occurs. In this case, part of the electrons passes from one body to another and a positive charge (lack of electrons) appears on the surface of one, and a negative charge (excess of electrons) appears on the surface of another body, i.e. a double electric layer (DEL) is formed (see drawing).

The stability of oil emulsions also depends on the presence of a double electric layer on the surface of emulsified particles, while particles having the same charges on their surface will mutually repel, causing the stability of the emulsion. To conduct a highly efficient process for purifying weakly concentrated oily water from oil, it is necessary to free the oil particle from the DES.

In the process of passage of charged particles sequentially through a fibrous hydrophobic polymer layer with a lower dielectric constant, and then through a fibrous hydrophilic layer with a higher dielectric constant, a DEL of oil particles flows into a DEL formed on the contact surface of two fibrous materials. The oil particles freed from the “armor shell” coalesce, increasing mass, and under the influence of gravity rise up the corrugations and collect in the upper part of the filter, where a pocket for collecting the oil product is provided.

In the claimed invention, a double electric layer is formed at the interface of two fibrous materials with different dielectric constants. Such an arrangement of ions, just as in an ionic atmosphere, is obtained under the influence of two opposite factors: electrostatic forces, which tend to attract ions tightly to the surface of the electrode, and thermal motion, which seeks to arrange ions randomly in solution - in the bulk structure of the corrugated material.

The formed double electric layer increases the coalescence rate of the dispersed phase of the emulsion. The aqueous phase is filtered through a layer of hydrophilic fiber and removed from the filter.

The following is an example of the manufacture of one of the possible variants of the claimed material.

Example 1

A substrate is prepared from polypropylene-based polymer fibers (PP - 2.2 tex 50%, PE - 1.7 tex 30%, TPV - 0.48 tex 20%), laid out and thermomechanically sealed by rolling or needle-piercing. The obtained fibrous layer is corrugated with heat setting at 90 ° C for 20 minutes, setting the thickness of the web layer to 1.0 - 3.0 cm, while the surface density of the web is 450-550 g / m ² . A layer with a surface density of 450-550 g / m ^{2 is formed} from a hydrophilic basalt fiber with a fiber diameter of 1-4 microns. Both layers are superimposed and fastened together by needle-piercing or rolling. The resulting material is immersed in an electrolyte solution and incubated in it for 2 hours.

The sorbent material was used as a filtering coalescing charge to separate emulsified oil products from water.

For this, the sorbent material was placed in a cartridge-type filter with a replaceable filter element, which is a perforated tube mounted along the axis of the filter housing. Around the perforated pipe is placed a sorbent material so that the outer wall of the pipe is in contact with a hydrophobic layer of fibrous material with a corrugated volumetric structure, and the ribs of the corrugations are vertically along the central pipe.

An artificially prepared water-oil emulsion is fed into the central tube, which passes through perforations into a layer of hydrophobic polymer fiber. The outer surface of the polymer layer of the sorbent is in contact with a superthin hydrophilic, fibrous basalt material, i.e. with a fiber with a polar positively charged surface.

The test results are shown in table 1.

Table 1 Qty Consumption, The content of oil products mg / l liters l / h missed water, l entrance Exit 10 3.6 5.8 0,026 60 8.0 5.1 0,025 one hundred 8.0 10,4 0.02 150 17.0 22.0 0.02 200 17.0 41.6 0.13

Example 2

A substrate is prepared from polypropylene-based polymer fibers (PP - 2.2 tex 50%, PE - 1.7 tex 30%, TPV - 0.48 tex 20%), laid out and thermomechanically sealed by rolling or needle-piercing. The resulting fibrous layer is corrugated by heat-setting 120 ° C for 2-3 minutes, setting the thickness of the web layer to 1.0-3.0 cm, while the surface density of the web is 450-550 g / m ² . A layer with a surface density of 450-550 g / m ^{2 is formed} from a hydrophilic basalt fiber with a fiber diameter of 1-4 microns and a glass fiber with a fiber diameter of 12-15 microns. The layers are laid on top of each other in the following sequence: hydrophobic polymeric fibrous material, basalt fiber, fiberglass. All layers are fastened together by needle piercing or rolling. The resulting material is immersed in an electrolyte solution and incubated in it for 2 hours.

The material was tested in laboratory conditions as well in the process of separating a super-stable oil-water emulsion when cleaning melt water from oil products from a roadbed in the Garden Ring area of Moscow. In the manufacture of the material used a layered composition of superthin basalt fiber and glass fiber with a thickness of 10-15 microns also in combination with polypropylene and polyester fibers, the results were similar to example 1.

The test results are shown in table 2.

table 2 amount Consumption, The content of petroleum products missed l \ h mg \ l water, l entrance Exit 5 60 4.14 0,03 twenty 60 3.62 0,025 40 60 1,62 0.02

Thus, a high separation efficiency of the emulsion was achieved, since in the process of its filtration a DEL was formed, which ensured:

- the transition of DES from particles of oil to DES at the interface between the layers of the material;

- coalescence of particles;

- removal of coalesced oil from the filter surface under the action of gravity through the hollow channels of the corrugations of the polymer non-woven material;

- separation of the accumulated film of the oil product and the conclusion of the purified aqueous phase;

- additional purification of the aqueous phase in the layer of hydrophilic material.

Claims (5)

1. Sorbent material for removing oil and oil products from aqueous solutions and separation of stable water-oil emulsions, containing a layer in the form of a body-corrugated non-woven fabric of polymer fibers with a hydrophobic surface, characterized in that it further comprises a layer of hydrophilic superthin fiber having a dielectric constant not less than 1.45 units higher than the dielectric constant of the layer of polymer fibers with a hydrophobic surface. 2. Sorbent material according to claim 1, characterized in that as a hydrophilic superthin fiber, it contains glass, basalt or metal fibers with a diameter of 1-15 microns or a combination thereof. 3. Sorbent material according to claims 1 and 2, characterized in that the mass ratio of the layer of polymer fibers with a hydrophobic surface to the layer of hydrophilic superthin fiber is (2-10): 1. 4. A method of manufacturing the sorbent material described in claims 1-3, which consists in forming a substrate layer in the form of hydrophobic polymer fibers, its thermomechanical compaction, the formation of a bulk corrugated fabric with heat setting at a temperature of 90-120 ° C, the formation of a layer of hydrophilic superthin fiber, the imposition of the aforementioned layers on top of each other, their bonding and aging in an electrolyte solution for 1-2 hours 5. The method of separation of stable water-oil emulsions, comprising filtering the emulsion through a sorbent material containing layers of materials with hydrophobic and hydrophilic surfaces, characterized in that the filtering is carried out through the material described in claims 1-3, first through a hydrophobic layer with a lower dielectric constant, and then through a hydrophilic layer with a higher dielectric constant, with the formation on the interface of these layers of a double electric layer that neutralizes the double electric layer on the surface of emulsified particles.