RU2687913C1 - Method of producing sorption material for collecting oil and oil products - Google Patents

Abstract

FIELD: oil, gas and coke-chemical industries.

SUBSTANCE: invention relates to materials for sorption of oil products and can be used for liquidation of emergency spills of oil and oil products on water surface of natural and artificial reservoirs, for treatment of waste water. Proposed method comprises making polypropylene fibre by polypropylene melt extrusion. Obtained fibres are twisted into bundle, which is pulled in atmosphere of water vapour at 105–130 °C to produce threads of specified thickness and cut into parts. Prepared fibrous material is subjected to modifying treatment with n-hexane at 60–65 °C for 15–20 minutes. After cooling, the treated fibre is separated from n-hexane, washed and dried in air at room temperature until complete evaporation of moisture.

EFFECT: technical result is improved working conditions, high environmental safety of method, possibility of recycling spent sorption material.

1 cl, 3 dwg, 1 tbl, 3 ex

Description

The invention relates to sorption and sorption-filtering materials that can be used to eliminate accidental spills of oil and petroleum products on the water surface of natural and artificial reservoirs, to clean the surface of wastewater and liquid waste production, whose activities are associated with the use of oil-containing liquids, as well as purification of ship oily water.

Sorption and filter materials in the process of cleaning oily water, in addition to adsorbing on the surface and in bulk oil and oil products, are contaminated with high molecular weight components of oil, such as asphaltenes and paraffins, as well as sludge contaminants deposited and accumulated on the surface of the fibers and in the pores the material, while regeneration by mechanical extraction does not allow to fully extract the above pollution from the volume of the sorption or sorption-filtering material, because ku for liberation and release contaminants require restructuring of the entire forming pore structure. In addition, sorption and sorption-filtering materials, after use, should be easily disposed of, preferably with a positive economic effect.

Known oil sorbent for collecting oil spills from the water surface (GB 2265628, publ. 1993.10.06) containing nonwoven fabric from polyolefin, mainly polypropylene, fibers, crushed polyolefin, mainly polyethylene, film and cellulose fibers, mainly fibers from wood pulp. A known oil sorbent cannot be regenerated and disposed of, which is a significant disadvantage.

A sorbing material for the removal of oil pollution is known (RU 2210644, publ. 1999.02.27), obtained by bonding two layers by needling, one of which is made of polypropylene fibers previously connected by needling, and the second, less dense, of hollow siliconized polyester fibers. The disadvantage of the sorbent material thus obtained is its low capacity for regeneration due to the presence of a static pore system formed by two fibrous layers bonded to each other by needle rolling, and the disposal of the spent sorbent material is hampered by the saturation of the material with water during operation.

A method of obtaining sorbent material for collecting oil and oil products (RU 2461421, publ. 2012.09.20) in the form of a corrugated non-woven fabric with a bulk density of from 0.01 to 0.06 g / cm ³ , thickness from 0.5 to 5.0 cm, made of hydrophobic polyethylene or polypropylene fibers, hydrophilic polyester or polyamide fibers and viscose fibers, including the formation of a web by fastening the mentioned hydrophobic and hydrophilic fibers with an aqueous emulsion of latex with heat treatment at 100-140 ° C, according to which hydrophilic fibers and pretreated with an aqueous latex emulsion comprising a styrene-butadiene rubber, and polimetiletilgidridsiloksan alkilsilikonat. The sorbent obtained in a known manner contains many ballast substances that do not contribute to its high efficiency, the presence of which is connected with the fact that to obtain a workable sorbent material from hydrophobic and hydrophilic fibers, besides using a binding agent, preliminary treatment of hydrophilic fibers with an aqueous emulsion of complex composition containing several organic compounds.

A method of obtaining fibrous synthetic material for use in the composition of filter materials and other products for the purification of water, air and soil from contamination by oil and heavy metals. By aerodynamic dispersion of the melt of commercial polymer from a series of polypropylene, polycarbonate or polyethylene terephthalate, as well as their waste (US 6524514, publ. 2003.02.25.) Material is obtained in the form of fine-fiber cotton-like mass from light gray to dark gray color with a bulk density of 160 up to 174 kg / m with a porosity from 81 to 81.5%, which collects the amount of pollutants, by weight up to 12 times its own weight. The resulting material is much lighter than water, floats on its surface, while it is regenerable, and, according to the authors, its properties are fully restored after mechanical pressing, which can be repeated up to 50 times. However, the mechanical spin does not allow to extract sludge contaminants from the volume of the material, high-molecular components of oil, such as asphaltenes and paraffins, which settle and accumulate on its fibers. Thus, the regeneration of a known material is not fully implemented, and the problem of final disposal is not solved.

The closest to the claimed is a sorbent obtained by modifying fibrous cellulosic material, which is used as a batting, cotton wool or waste cotton production, water-repellent solution of oxidized atactic polypropylene in tetrachloroethylene (RU 2463106, publ. 2012.10.10). Atactic polypropylene is oxidized at a temperature of from 180 to 240 ° C for 4-6 hours, dissolved in tetrachlorethylene and the resulting solution containing 0.4-0.5% oxidized atactic polypropylene impregnates fibrous cellulosic material, while the excess solution is drained and returned to cycle. Impregnated fibrous cellulosic material is dried to a constant weight, passing through it heated air, the tetrachlorethylene vapors formed thereby condense and return to the beginning of the process.

When working with tetrachlorethylene, special safety measures are required: this solvent is dangerous for the environment and human health, and can also damage the metal parts of instruments and equipment. When it comes into contact with hot surfaces or with a flame, it decomposes to form toxic and corrosive vapors (hydrogen chloride, phosgene, chlorine), when in contact with moisture it slowly decomposes to form trichloroacetic acid and hydrochloric acid. Reacts with metals such as aluminum, lithium, barium, beryllium. At ordinary temperature, dangerous indoor air pollution occurs gradually: the process of evaporation of this substance at 20 ° C is rather slow.

This method of obtaining a sorbent for cleaning water surface and soil from oil and oil products allows you to get a sorbent with high sorption of oil and oil products in the presence of water, with a sufficiently high ability to retain absorbed oil and oil products. Such a sorbent has a high buoyancy, capable of mechanical regeneration (spin up to 20 times) with preservation of sorption capacity. Can be disposed of in road construction, burning, biodegradation.

However, due to the static nature of the pore space, the regeneration of the sorbent is difficult. Mechanical pressing does not allow to remove sludge pollution and high-molecular components of oil from the pore volume of the material, such as asphaltenes and paraffins, which settle and accumulate on its fibers and lead to a decrease in the sorption capacity of the sorbent by reducing the volume of the pore space.

Disposal in asphalt or asphalt concrete during the construction of roads requires expensive material preparation in the form of chopping or crushing, as well as prestressing the fibers. Otherwise, such recycling will reduce the quality of the road surface.

Disposal of the sorbent by incineration is difficult, because in the process of work, moisture accumulates in the pores, which does not allow it to be fully burned. In addition, burning is an undesirable process that pollutes the atmosphere and the environment.

The objective of the invention is the creation of a technologically advanced method of obtaining an effective sorption filtering material for collecting oil and oil products, which has a high sorption capacity, the ability to regenerate due to a mobile pore system and is easily utilized in asphalt or asphalt-concrete as a reinforcing additive in road construction without prior preparation and with obtaining a positive economic effect from recycling.

The technical result of the method is to increase the efficiency of the resulting sorption material due to the moving system of pores, bounded by the length of the fibers (12-24 mm), the prestressing of the fibers by drawing.

This technical result is achieved by a method of obtaining a sorption filtering material for collecting oil and petroleum products, including modifying processing of a fibrous material, in which, unlike the known, use is a fibrous material obtained from a polypropylene melt by extrusion, with polypropylene melt fibers obtained from a melt which is pulled out in the atmosphere of water vapor at 105-130 ° С to obtain filaments 35-40 microns thick, cut into pieces 12-24 mm long and carry out their modification treatment with n-hexane C ₆ H ₁₄ at a temperature of 60-65 ° C for 15-20 minutes, after cooling, the treated fiber is separated from n-hexane, washed and dried in air at room temperature for 24 hours.

The method is as follows.

By extrusion from a melt of granulated polypropylene, polypropylene yarns are obtained; they are connected to a common rope with a diameter of 3-5 cm, which is drawn at 105-130 ° C in an environment of water vapor to obtain fibers with a diameter of 35-40 μm. An elongated rope is cut into short threads, mainly 12-24 mm long.

The obtained fibrous material is subjected to a modifying treatment by immersing it in a container with C ₆ H ₁₄ n-hexane, so that the fibers are completely covered with liquid, placed in a sealed heating device: a closed electrically heated bath or in an autoclave and heated to a temperature of 60-65 ° C . At the same time, the heating time depends on the volume of n-hexane with a fibrous material: a larger volume is heated more slowly (100 ml is heated for no more than 10 minutes, 10–20 l for 30 minutes). At a temperature of 60-65 ° C, the fiber is kept in n-hexane for 10-15 minutes, then left to cool completely to room temperature. The n-hexane is completely filtered off, the modified polypropylene fiber is removed and the mixture is thoroughly washed with running water or with plenty of water.

All work with n-hexane is carried out as far as possible in hermetic containers and with the obligatory presence of a balanced supply and exhaust ventilation.

Dry the treated and washed polypropylene fiber in air at room temperature for about a day until the moisture evaporates completely.

Released filtered n-hexane is recyclable.

The complete functional scheme for obtaining a sorption filter material based on modified polypropylene fiber by the proposed method is shown in FIG. one

However, the sorption filtering material can be obtained by a simplified scheme, with the exception of the stage of obtaining the original polypropylene fiber, through the use of the finished fibrous material made of polypropylene, which is known in Russia under the trade names: fiberglass (polymeric, synthetic, multifilament), fibrin, analogue fibro-fiber Propex (Propex) and Fibrin (Fibrin). Thus, any fibrous material made of polypropylene can be used, without limitation, including all materials sold under the listed names.

FIG. 2 shows the SEM images of the surface of the fibers of the sorption filter material obtained by the proposed method.

The sample surface is relatively uniform, covered with pores, among which mesopores with a size of about 10 nm prevail. Porous structure branched. The specific surface area, measured by the Greg-Sing method, was 2.198 m ² / g. The volume of micropores is 0.001 cm ³ / g. The average pore size is 1.896 nm.

Evaluation of the sorption properties of the resulting sorption filtering material was carried out on the basis of studies of the behavior of samples in aqueous and organic media in accordance with ASTM F: 726-12 at a test temperature of 22 ± 3 ° C and a relative humidity of 20-70%.

Sorption capacity was determined by the following types of petroleum products: fuel oil brand M-100, diesel fuel, M8B universal motor oil, I-40A industrial oil.

The results of the determination of the sorption capacity of the sorption filter material obtained by the proposed method are shown in table 1.

Note:

V _NP - the volume of petroleum product, ml;

m ₀ is the mass of the dry sample, g;

m ₁ is the mass of the sample in an oil-saturated state, g;

Δm = m ₁ -m ₀ , g;

Q - sorption capacity, g / g.

Examples of specific implementation of the method

Polypropylene fiber obtained by extrusion according to a known method described in the patent RU 2318085, publ. 2008.02.27, twisted into bundles, pulled and cut into pieces, as described above. Then placed in an airtight container, filled with n-hexane C ₆ H ₁₄ brand x.h. (TU 2631-001-54260861-2013) in such a way as to completely cover the fiber (T: W about 1: 5-6), tightly close the container and put it in the drying cabinet under the hood. After processing, the fiber was removed and washed with distilled water (volume 2 l). Drying of the treated fibers was carried out at room temperature for 24 hours.

The surface morphology of the modified, washed and dried material was examined using an S-5500 scanning electron microscope (Hitachi, Japan).

The value of the specific surface and the volume of micropores of the polypropylene fibrous material obtained by the proposed method were measured using a Sorbtometer-M specific surface analyzer (KATAKON, Russia) by low-temperature (-196 ° С) nitrogen adsorption. The specific surface was calculated by the Brunauer-Emmett-Teller method and the comparative Gregg-Sing method using the software attached to the instrument.

Example 1

A weighed 16 g of fiber obtained by extrusion from a melt of granulated polypropylene and prepared in accordance with the proposed method, poured 100 ml of n-hexane, tightly closed and placed in a drying cabinet at a temperature of 23 ° C. Within 8 minutes, the temperature was raised to 65 ° C, kept at this temperature for 15 minutes, the heating was turned off, and after complete cooling, n-hexane was decanted for reuse. The resulting material was thoroughly washed, rinsed with distilled water and left for 24 hours to completely evaporate the moisture.

The result is shown in FIG. 2

Example 2

A weighed portion of 16 g of polypropylene fiber of Polymer LLC, Russia, was treated analogously to example 1, poured 100 ml of n-hexane, increased the temperature to 60 ° C and kept at this temperature for 20 minutes, after cooling, washed and dried.

The results are similar to those obtained in example 1.

Example 3

A sample of 120 l of polluted crude oil was passed through a filter column for 30 days (4 l per day). The initial concentration of oil was 127.0 mg / l. The volume of filter loading - 1.5 liters. A filter consisting of an AEG-W14 body, 350 mm in height, and 120 mm in diameter was used as a filter column. The UPF-Container cartridge, height - 250 mm, diameter - 63 mm was filled with a sorption-filtering material based on polypropylene fiber, obtained by the proposed method according to example 1.

Water was supplied by the ETATRON B3-VPER peristaltic dosing pump; delivery - from 1 to 12 l / h. The water transmission rate was 3.75 l / h (1.25 m / h).

It was determined that the use of modified polypropylene fiber material is effective in a dynamic mode of sorption. At filtration rates of up to 5 m / h, the purge rate was 99.85% with a decrease in the concentration of oil from 120.0 to 0.18 mg / l.

FIG. 3 shows the result of an experiment on filtering polluted oil of seawater through a filter loaded with polypropylene fiber-fiber treated by the proposed method (filter with loading and cartridge after filtration are shown).

Claims (2)

1. A method of obtaining a sorption-filtering material for collecting oil and petroleum products, including modifying processing of fibrous material, characterized in that using fibrous material obtained from a polypropylene melt by extrusion, while obtained from a melt polypropylene fibers are twisted into a bundle, which is pulled in the atmosphere steam at 105-130 ° C to obtain filaments of 35-40 microns thick, cut into pieces, modifying treatment is carried out with n-hexane, C ₆ H _14, at a temperature of 60-65 ° C for 15-20 minutes, le cooling of the treated fiber was separated from n-hexane, washed and dried in air at room temperature for 24 hours. 2. The method according to p. 1, characterized in that after separation of the treated fiber, n-hexane is returned to the working cycle.

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