RU2356623C2 - Sorbent material and method of its fabrication - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention refers to sorbents of oil and oil products. Sorbent material consists of a layer of thermo-plastic polymer fibers bound between them and of a secured on fibers substance with hydrophobic properties; the substance corresponds to disperse carbon; particles of disperse carbon are of 50-1000 Angstrom size; share of carbon attached to fibers is from 1 to 25% of fibers weight. The method of fabrication of sorbent material consists in forming the layer out of thermo-plastic polymer fibers, in treating them with the substance possessing hydrophobic properties and in thermal processing of material to facilitate thermal binding of fibers; also as a substance with hydrophobic properties disperse carbon is used; thermal treatment is performed to attach carbon to the surface of fibers; after that not attached particles of carbon are removed.

EFFECT: invention facilitates increased sorbent property of material, rate of sorption and regeneration ratio and also increased floatability of material.

7 cl, 3 tbl

Description

The invention relates to sorbents of oil and oil products (NP) used in the response to emergency spills of NP, and to methods for their preparation.

Mineral, organic (including natural plant origin), synthetic polymer sorbents in the form of powders, granules, plates, including non-woven materials, are known for this purpose. Sorbents based on polymer non-woven materials (for example, known from RU 2240865 C1, RU 2254915 C1) are made in the form of paintings with different lengths, thicknesses and widths from fibers of various polymers, both with polar groups and without. The main characteristics that determine the properties of sorbents based on polymer nonwoven materials are: sorption ability, defined as the ratio of the weight of the sorbed NP to its own weight of the sorbent (kg / kg), sorption rate, defined as the ratio of the weight of the sorbed NP to its own weight of the sorbent per unit time ( kg / kg / min), the regeneration coefficient, defined as the ratio of the amount of separated NP (for example, when squeezing the sorbent) to the sorbed NP when the sorbent is completely saturated, the maximum amount the cycle of sorbent regeneration by extraction until the sorption capacity of the sorbent drops or until it is mechanically destroyed. For the sorbents used to collect NPs spilled on the water surface, the following properties are significant or determining - the buoyancy unlimited in time of the sorbent saturated with NP or not in contact with the NP, the wettability and fillability of the nonwoven material with water, the degree of displacement of the sorbed NPs with water.

These characteristics are determined by the nature of the polymer and the physical dimensions (length, diameter, density) of the fibers used to produce the nonwoven material, the density of the material (specific, surface, volume), the method of fiber bonding (needle-punched or heat bonding), the presence or absence of surface substrates. For the best domestic and foreign NP sorbents based on nonwoven materials, the sorption capacity is in the range from 15 to 30 kg / kg, the sorption speed does not exceed 1.5 kg / kg / min, the regeneration coefficient in one cycle “sorption - spin” does not exceed 60 % Almost all sorbents used to eliminate emergency oil spills do not have positive buoyancy even in the case of polymers with a specific gravity below 1 g / cm ³ . The greatest sorption ability of known NP sorbents is activated carbon (up to 52 kg / kg), however, it is practically not used to eliminate spills of NPs due to almost zero regenerative ability; NPs are not removed during the spin cycle or centrifugation, and the extraction is unacceptable due to the high cost of the subsequent recovery process. Therefore, once used activated carbon must be disposed of by burning, which is not cost-effective.

It is possible to increase the sorption ability, the sorption rate, and the regeneration coefficient of nonwoven materials due to the immobilization of substances with the most pronounced oliophilic and hydrophobic properties on the fiber surface.

Closest to the proposed is a sorbent material containing several layers of polymer fibers bonded to each other, and treated with a hydrophobic substance. A method of producing a sorbent material includes forming a polymer layer from a fibrous substrate, in which the fibers are bonded to each other, wherein the constituent layers of the fibrous substrate are pre-compacted, then mechanical bonding is performed and a set of fibrous layers is formed in a certain sequence, after which the set of fibrous layers is subjected to thermal processing in predetermined modes for their thermal bonding, in addition, the entire set of fibrous layers before or after thermal treatment Work can be treated with a hydrophobic substance (RU 2001114436 A, 05/10/2003).

The objective of the invention is to increase the sorption ability of the sorbent material, sorption speed and regeneration coefficient, as well as increase the buoyancy of the material.

The problem is solved in that in the sorbent material, including a layer of thermoplastic polymer fibers bonded to each other, and a substance with hydrophobic properties fixed to the fibers, the substance with hydrophobic properties is dispersed carbon, the particles of which have sizes of 50-1000 Angstroms, and the proportion fixed to carbon fibers is preferably from 1 to 25% by weight of the fibers.

The layer of thermoplastic polymer fibers may be a woven or non-woven material.

The problem is also solved by the method of obtaining the sorbent material, which consists in forming a layer of thermoplastic polymer fibers, treating it with a substance with hydrophobic properties, and heat treating the material to ensure thermal bonding of the fibers, and dispersed carbon is used as a substance with hydrophobic properties. the processing is carried out with carbon fixing on the surface of the fibers, after which loose carbon particles are removed.

In addition, it is preferable to use dispersed carbon with a particle size of 50-1000 Angstroms, and that the amount of dispersed carbon for processing is chosen so that the proportion of carbon attached to the fibers is from 1 to 25% by weight of the fibers.

In addition, the formation of a layer of thermoplastic polymer fibers is carried out in the form of a woven or non-woven material.

The essence of the invention lies in the fact that to improve the sorption properties of the fibrous material, dispersed carbon is immobilized with particle sizes from 50 to 3000 angstroms. The introduction of carbon into the composition of the polymer fibers can be carried out either at the “blend” stage or at the stage of formation of the specified structure of the nonwoven fabric fibers before the stage of thermal crosslinking of the fabric, at which both the fibers crosslink at the points of contact and the carbon particles are attached to the fiber surface . Thermal crosslinking of the fibers of a woven or nonwoven material, the immobilization of a hydrocarbon on the surface of the fibers occur simultaneously at a temperature that is 5-10 ° C higher than the melting temperature of the polymer (s) of which the fiber is made.

As dispersed carbon, gas channel soot, technical carbon furnace, fine-granulated carbon, etc. can be used.

The following is an example implementation of a method for producing sorbent material.

In accordance with the current technological regulations (PerioTech technology) for the production of non-woven materials, two batches of non-woven material were produced, differing in composition.

The composition of the mixed fiber composition of the batch No. 1:

PP - 70% (polypropylene fiber 0.33-1.7 tex, 66 mm long).

BKV (PP) 30% (polyester bicomponent fiber of the "core - sheath" type according to the technical documentation of a foreign company).

The surface density of the canvas is 500-550 g / sq.m.

Thickness - 25 mm.

Width - 1.0 m.

With two substrates.

The composition of the mixed fiber composition of the batch No. 2:

PP - 50% (polypropylene fiber 1.7-2.2 Tex, 66 mm according to TU 6-1300204077-90).

BKV (PP) 30% (polyester bicomponent fiber of the "core - sheath" type according to the technical documentation of a foreign company).

PE - 20% (1.7 tex polyester fiber, 66 mm according to TU 6-1300204077-90).

The surface density of the canvas is 500-550 g / sq.m.

Thickness - 25 mm.

Width - 1.0 m.

With two substrates.

Before the thermal bonding stage, compressed air with carbon particles with the following characteristics was supplied through a die to the formed nonwoven fabric of batches No. 1 and No. 2.

Product specifications: Carbon technical furnace conductive P267-E TU 3811574-86.

Specific external surface, m ² / g 140-160 Specific adsorption surface, m ² / g 210-250 Dibutyl phthalate adsorption, ^cm3 / 100g 160-180 pH of an aqueous suspension 6-8 Mass fraction of losses at 105 ° С,%, no more 0.8 Ash content,%, no more 0.40 Mass fraction of total sulfur,%, no more 0.7

Mass fraction of the residue after sifting through a sieve with a mesh:

0045K according to GOST 3584-73,%, no more 0.08 (i.e. no more than 100 Ǻ) 014K in accordance with GOST 3584-73,%, no more 0.02 05K in accordance with GOST 3584-73,%, no more 0,0008 Granular bulk density carbon black, g / l, not less 200 Specific volumetric electric resistance, Ohm.m, no more 0.002

The concentration of carbon particles in the air stream was varied so that the proportion of carbon adsorbed by the fibers was in the range from 1 to 25% by weight of the fibers. Then, in order to fix the sorbed carbon on the surface of the fibers of the nonwoven fabric, they passed through a heat chamber. The temperature and the residence time of the web in the chamber corresponded to the modes prescribed in the technological regulations for the stage of thermal bonding of the fibers: temperature in the range of 145-150 ° C, time 45-55 seconds. At this stage, in parallel with the thermal crosslinking of the fibers, carbon particles were thermally bonded to the surface of the fibers. Excessive loose carbon was removed by shaking the web. Control and carbon-fiber-containing samples were weighed on a laboratory balance with an accuracy of 10 mg. The sorption capacity of carbon-modified non-woven material was determined as the ratio: the maximum weight of the sorbed hydrocarbon (for the purity of the experiment, industrial oil was used in accordance with GOST as the least different in characteristics, in contrast, for example, from oil, fuel oil and other petroleum products) to the weight of the sample. The sorption rate was determined as the ratio of the weighted amount of sorbed oil to the weight of the sample per unit time (1 min). The buoyancy of samples in water was determined visually and by the weight gain of water in the sample after 5 minutes of contact with water.

The regeneration coefficient (the number of sorption-spin cycles with a load of 0.1 kg / cm ² until the sorption capacity decreases compared to the second cycle) is characterized by the number of cycles.

Table 1 shows the characteristics of samples of sorption material with different carbon contents.

Table 1 Sample no. Carbon content% Sorption ability, g / g Sorption rate, g / g / min Buoyancy 1-0 control 0 27.48 2.7 Conditionally
floating,
completely
immersed 1-1 1.72 47.16 21.6 Buoyancy
samples 1-1 - 1-5
absolute in water:
not sinking
practically not
wetted 1-2 3.92 48.52 23,4 1-3 4.08 48.21 23.1 1-4 7.14 46.51 24.2 1-5 9.43 45.08 22.7 2-0 control 0 32.16 3,1 Buoyancy
negative
falls to the bottom 2-1 4.92 47.13 24.7 Buoyancy
samples 2-1 - 1-5
absolute in water:
not sinking
practically not
wetted 2-2 7.61 46.92 25.1 2-3 9.41 45.77 24.6 2-4 12.55 46.01 25.6 2-5 15.87 45.19 24.1

Regeneration coefficients were determined by testing (sorption - spin) control samples and samples 1-3 and 2-2. Table 2 shows the test results.

table 2 Sample No. Regeneration rate 1-0 Control 314 1-3 368 2-0 Control 473 2-2 494

Studies of two functions were carried out - the sorption capacity of the material (g / g) and the sorption rate (g / g / min) depending on the particle size of the immobilized dispersed carbon on the samples of nonwoven material. Samples 1-2 and 2-2 were taken as control samples. The particle size of the dispersed carbon ranged from 100 Angstroms to 5000 Angstroms with a mass fraction of carbon ranging from 4 to 8%.

The experimental results are summarized in table 3.

Table 3 Sample No. Carbon content% Particle Size, Å Sorption ability, g / g Sorption rate, g / g / min 1-2 3.92 240 48.52 23,4 1-21 4.12 one hundred 49.26 24.5 1-22 7.14 300 48.71 24.4 1-23 5.61 500 47.84 25,2 1-24 7.93 800 48.73 24.7 1-25 6.77 1000 48.22 24.6 1-26 6.42 5000 36.55 22.3 2-2 7.61 240 46.92 25.1 2-21 5.12 fifty 48.98 26.8 2-22 8.02 300 46.36 25,2 2-23 4.69 500 47.52 25.0 2-24 7.11 800 46.79 25.1 2-25 6.07 1000 46.46 24.7 2-26 5.28 5000 37.48 23,2

The conclusion of table 3: the maximum values of the sorption ability and sorption rate of petroleum products are achieved with particle sizes of dispersed carbon in the range of values from 50 to 1000 Angstroms.

Findings:

1. The increase in sorption ability during the immobilization of carbon particles on the surface of the fibers for samples of batch 1 is an average of 1.7 times for samples of the batch of 2-1.4 times.

2. The increase in the rate of sorption during the immobilization of carbon particles on the surface of the fibers for batch 1 samples is 8.5 times on average for batch samples 2-7.7 times.

3. When carbon particles are immobilized on the surface of fibers for samples of batches 1 and 2, absolute buoyancy is achieved (the surface of the samples is practically not wetted by water, the penetration of water into the thickness of the samples is not fixed).

4. The immobilization of carbon on the surface of the fibers of the nonwoven material contributes to some increase in the coefficient of regeneration of the material.

5. According to its characteristics, the modified material has no analogues.

Claims (7)

1. Sorbent material, comprising a layer of thermoplastic polymer fibers bonded to each other, and a substance with hydrophobic properties fixed to the fibers, characterized in that the substance with hydrophobic properties is dispersed carbon, the particles of which have sizes of 50-1000 Å. 2. The material according to claim 1, characterized in that the proportion of carbon fixed to the fibers is from 1 to 25% by weight of the fibers. 3. The material according to claim 1, characterized in that the layer of thermoplastic polymer fibers is a woven or non-woven material. 4. A method of producing a sorbent material, which consists in forming a layer of thermoplastic polymer fibers, treating it with a substance with hydrophobic properties, and heat treating the material to provide thermal bonding of the fibers, characterized in that dispersed carbon is used as a substance with hydrophobic properties, the heat treatment is carried out with carbon fixed on the surface of the fibers, after which loose carbon particles are removed. 5. The method according to claim 4, characterized in that they use dispersed carbon with a particle size of 50-1000 Å. 6. The method according to claim 4, characterized in that the amount of dispersed carbon for processing is chosen so that the proportion of carbon fiber attached to the fibers is from 1 to 25% by weight of the fibers. 7. The method according to claim 4, characterized in that the formation of a layer of thermoplastic polymer fibers is carried out in the form of a woven or non-woven material.