RU2708309C1 - Method of producing hydrophobic oil sorbent and device for its implementation - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: group of inventions relates to production of disperse oil sorbents. Hydrophilization chamber with the loaded porous aluminosilicate material is evacuated to residual pressure of 10–60 kPa, the material is treated in the medium of superheated water vapor. Temperature is increased to 500–550 °C, maintaining pressure in chamber within atmospheric pressure. It is held at the achieved temperature of 500–550 °C for 2–3 hours. Then, steam is discharged into the pre-evacuated receiver to residual pressure in the working chamber of 10–20 kPa. Water repellent is supplied in liquid phase at rate of 0.3–0.6 g per 1 l of volume of hydrophilization chamber, the temperature is maintained at 500–550 °C for 5–20 minutes. Heating is switched off and cooled to temperature lower than 120 °C is sucked in. Proposed device represents horizontally installed tight cylindrical chamber with door-cover and with longitudinal inner ribs for arrangement of trays. Chamber is equipped in the upper part with a branch pipe with a shut-off valve for supply into the hydrophobizator in liquid phase and an evaporator for the hydrophobizator. In lower chamber is equipped with cuvette-evaporator for water. Proposed device comprises branch pipe with shutoff valve to connect vacuum receiver.

EFFECT: technical result consists in improvement of quality of hydrophobic coating of sorbents and in expansion of range of recovered oil sorbents.

4 cl, 2 ex, 2 tbl, 1 dwg

Description

The invention relates to the production of dispersed oil sorbents, as well as to the equipment used for this, and can be used in the production of hydrophobic regenerable sorbents for the treatment of hydrocarbons from industrial wastewater, oil depots, gas stations, oil platforms, oil-containing bilge and ballast waters of ships, in particular, sorbents used as a load in devices for cleaning liquid media from oil products.

Known (RU 2064463, publ. 1996.07.27) is a method of hydrophobizing the surface of dry dispersed materials in a stable vortex flow of a cyclone chamber, comprising supplying an aerodispersed mixture with a temperature of 200-400 ° C to the vortex chamber from above, separating the carrier gas from the original dispersed material, processing said material by gaseous water repellent at 400-700 ° C followed by repeated separation of the gas phase. The insufficiently long residence time of the treated dispersed material in the environment of the water repellent, as well as the instability of the condensation process of the vapor of the water repellent on the treated surface due to the difficulty of providing a stable temperature gradient between the surface and the vapor of the water repellent, do not allow to obtain a high-quality hydrophobic coating. In addition, continuously working hydrophobic gas generators require continuous removal of the latter and its subsequent disposal, which further complicates the known method and makes it environmentally unsafe.

Known (RU 2337751, publ. 2008.11.10) is a method for producing carbon-containing sorbents based on layered aluminosilicates for the purification of water from multicomponent contaminants, including the simultaneous calcination and treatment of aluminosilicate with hydrocarbons of petroleum origin at a temperature of 500-700 ° C until a hydrophobic nanolayer and carbon content in sorbent 0.7-1.1%. The nomenclature of sorbents is limited to vermiculite with a particle size of 1-10 mm. The quality of the hydrophobic coating of the sorbents obtained in a known manner is not guaranteed to be high due to the fact that while firing and hydrophobizing at the same time, it is impossible to provide the necessary condensation conditions for the hydrophobizing agent; in addition, the presence of oxygen during firing leads to burnout and increased consumption of water repellent.

Known (RU 2340393, publ. 2008.12.10) is a method for producing sorbents effective in collecting oil, oil products, oils and fats, other liquid hydrocarbons from a water surface, including granulating a mixture of aluminosilicates and aluminoferrites taken in a ratio of 10-20: 1, activation the resulting material with an electromagnetic field of 10-20 V / m and an acoustic field with a frequency of 50-100 Hz at an exposure intensity of 20-40 dB, IR radiation, impregnation with a water repellent, mainly an aqueous solution of isopropyl alcohol mixed with polyethylene hydrosilicon and with unsaturated fatty oleic acid, which is metered using a compressor with an adjustable valve into a working chamber mixed with compressed gas (air, a mixture of air with argon and nitrogen, or argon, or a mixture of argon with nitrogen), heated to 200-400 ° C when supplied through the cavity of the heater. The activation of the material by electromagnetic and acoustic fields, light radiation complicates the method and requires complex hardware design, which greatly increases the cost of sorbent production, but does not guarantee its quality completely. In addition, in the process of implementing the known method, flue gases are formed that require wet cleaning, and, accordingly, waste water that requires disposal, which also complicates the method and increases costs. The regeneration of the spent sorbent obtained in a known manner is not provided, which also reduces the profitability of its production.

The method of producing sorbents for purifying water from organic impurities, in particular sea water from petroleum products (SU 1606182, publ. 1990.11.15), which includes drying porous material, in particular expanded perlite, expanded clay, vermiculite, is selected as the closest to the claimed one. in a working chamber at a temperature of 300-500 ° C, evacuation to a pressure of no higher than 250 mm RT. Art., treatment of the material with a gasified hydrocarbon water repellent, which is used as fuel oil, liquid bitumen, tar, technical oils, at 180-220 ° C until normal pressure is reached, followed by cooling to a temperature of 10-20 ° C below the condensation temperature of the water repellent and formation hydrophobic film.

The quality of the hydrophobic coating obtained by a known method of a sorbent of a single charge is different due to differences in temperature, which cannot be controlled and maintained exactly the same throughout the volume of the loaded material during the condensation of the hydrophobizer. The sorbent at the walls of the working chamber cools faster, as a result of which a hydrophobic film is formed on it with better continuity and with a larger, sometimes excess, thickness. The sorbent located closer to the center of the chamber, in the depth of loading, where a smaller amount of water repellent penetrates, and in addition, the temperature gradient is insufficient for its complete condensation, reveals a weaker hydrophobic coating. In addition, drying in a gaseous coolant stream contributes to the destruction of granules of low-strength materials, such as perlite, vermiculite, and obtaining a coolant by burning liquid hydrocarbons increases the cost of sorbent production and leads to environmental degradation due to the release of combustion products into the atmosphere.

Also closest to the claimed is a device for implementing the known method, which is the subject of the invention described in the copyright certificate SU 1606182, publ. 1990.11.15.

Other known devices do not provide hydrophobization of granular porous materials.

It is known (RU 105844, publ. 2011.06.27) a device for producing a sorbent for cleaning the surface of water from oil products, providing hydrophobization of cellulosic material (peat, sawdust, wood shavings, wood chips, cotton wool, cotton rags, etc.) containing an autoclave with limited air access to the heated material, the heater, which is a microwave source, equipped with screw conveyors for loading and unloading material. Screw loading does not provide complete tightness of the autoclave, which does not exclude the access of air to the heated material and the release of gaseous reaction products into the environment. In addition, the presence of air inside the autoclave creates a danger of ignition of the vapor of the water repellent with an uncontrolled increase in pressure.

It is known (RU 14531, publ. 2000.08.10) a device for the preparation of hydrophobized sorbent on a carrier of textile or non-woven material, for example, technical batting, structurally not intended for the processing of dispersed materials. The device contains a body inclined by 5-30 ° with respect to the horizontal plane in the form of a segment of a rectangular pipe with inlet and outlet hatches, with a reel placed on top with a carrier, an assembly for supplying a mixture of a gaseous substance with a substance for impregnation and heated air to the working areas for subsequent drying, a unit for regulating the pressure and flow rate of substances supplied to the housing, connecting pipelines.

A device for the hydrophobization of powdered materials is known (RU 2544699, publ. 2015.03.20) in the form of a rotating drum-type apparatus with a cylindrical body, at the edges of which two rims and a cover with two symmetrically located windows with fluoroplastic membranes are fixed. A container with a jacket and a central channel is attached to the bottom inside the body, the open or closed position of which is provided by the tip of the movable hollow rod with holes for the hydrophobizing liquid to enter the container. The body cavity is in communication with the evacuation system through a cutter and a nozzle for the removal of by-products formed in the process of hydrophobization. The known device is made rotating, and in this case, the connection to the evacuation system by means of a simple fitting does not provide sufficiently reliable tightness, which is fraught with air leakage into the working chamber, as well as the release of by-product vapors into the atmosphere.

The closest analogue (SU 1606182, publ. 1990.11.15) of the claimed device for its intended purpose, as well as constructively and for the achieved result, is, as noted above, a device for hydrophobization of porous sorption material (expanded perlite, brick chips, expanded clay, slag, vermiculite and etc.) in the gas phase of a hydrocarbon substance (fuel oil, liquid bitumen, etc.), which is a cylindrical chamber configured to seal and evacuate and equipped with means for supplying a heat carrier gas for drying material and water repellent in the gas phase.

Described in the known device, drying in a coolant stream contributes to the destruction of granules and low-strength materials, such as vermiculite, foam silicate, perlite, worsening the quality of the obtained hydrophobized sorbent. In addition, the supply of coolant obtained by burning liquid hydrocarbons increases the cost of sorbent production and leads to environmental degradation.

The objective of the invention is to develop a method and device for producing hydrophobic oil adsorbents based on porous aluminosilicates with a high quality hydrophobic coating, capable of regeneration after use, not requiring significant costs and not causing damage to the environment in their production.

The technical result of the invention is to improve the quality of the hydrophobic coating of the obtained sorbents and to expand the range of hydrophobized sorbents regenerated after use, while improving the environmental safety of production and reducing costs.

The technical result is achieved by a method for producing a hydrophobic oil adsorbent, including drying a porous silicate material in a working chamber, processing it under reduced pressure with a gasified hydrocarbon hydrophobizing agent, followed by cooling to a temperature below the condensation temperature of the hydrophobizing agent, in which, unlike the known one, drying is carried out after evacuation of the hydrophobization chamber to residual pressure of 10-60 kPa in the atmosphere of superheated steam formed in the cell-evaporator with increasing temperature Ura in the chamber up to 500-550 ° C, during which the pressure in the chamber is controlled, while preventing it from increasing above atmospheric pressure by releasing steam, after reaching a predetermined temperature, maintain it for 2-3 hours, then dump the steam into a previously evacuated receiver until residual pressure in the working chamber of 10-20 kPa, a water-repellent agent is introduced into the working chamber in the liquid phase at the rate of 0.3-0.6 g per 1 liter of its volume, after which the temperature is maintained at 500-550 ° C for another 5-20 min , then turn off the heat, allow the contents of the camera to cool to eratury below 120 ° C, is admitted into the air chamber, allowed to equilibrate its temperature of the material at ambient temperature, whereupon unloading.

The specified technical result is also achieved by a device for implementing a method for producing a hydrophobic oil adsorbent, which is a cylindrical chamber made with the possibility of sealing and evacuation and equipped with means for supplying a water repellent, which, unlike the known one, is installed horizontally and made with a sealed door-lid for loading and unloading sorbent and longitudinal internal ribs for placement of pallets with water-repellent material, equipped with a nozzle with a locking valve ohm for supplying a water-repellent agent in the liquid phase from an external container, a nozzle with a shut-off valve for connecting a vacuum receiver with a volume exceeding the chamber volume, equipped with a vacuum pump and a vacuum manometer, while an evaporator for water repellent is installed in the upper part of the chamber, and in the lower evaporator cuvette for water.

In an advantageous embodiment of the invention, the camera is equipped with an electric heating device, a thermocouple and is made with insulation.

In addition, the door-lid of the hydrophobization chamber is equipped with cooling means.

The proposed device, a general view of which is shown in the drawing, contains a cylindrical horizontally located working chamber (hydrophobization chamber) 1, equipped with an electric heating device, a thermocouple for temperature control and thermal insulation (not shown in the drawing), made with a hermetically sealed cover 2 (or, more precisely, with a horizontal arrangement of the cylindrical body, door), which is equipped with cooling means. The inner walls of the hydrophobization chamber 1 are provided with longitudinal ribs for placing perforated trays 3 with hydrophobizable material on them. A metal cuvette-evaporator 4 for water is placed in the lower part of the chamber 1, and the evaporator 5, which is an inclined trough, abuts against the rear wall of the cabinet, is installed under the nozzle for supplying the water repellent. The hydrophobization chamber is equipped with a steam outlet pipe with a shut-off valve 6, a hydrophobizer supply device 7 with a shut-off valve 8 and a manometer-vacuum gauge 9.

The hydrophobization chamber 1 is connected to the vacuum receiver 10 by means of a connecting pipe 11 with a shut-off valve 12. The vacuum receiver 10 in the lower part has a pipe with a shut-off valve 13 for condensate discharge and a vacuum gauge 14.

The vacuum in the vacuum receiver is provided by a vacuum pump 15 connected to the receiver 10 by means of a pipe 16 having a shut-off valve 17.

The proposed device operates as follows, ensuring the implementation of the proposed method.

Previously, using the vacuum pump 15 with the valve 17 open and valve 12 closed in the receiver 10, a vacuum is created to a residual pressure of 5-15 kPa, which is controlled by a vacuum gauge 14. Upon reaching a predetermined residual pressure, the vacuum pump is turned off, valve 17 is closed.

The raw material to be hydrophobized (porous aluminosilicate material) is laid on perforated trays 3 and placed in chamber 1. Heating and drying of the raw material is carried out under static conditions of chamber 1 in an environment of superheated water vapor. For this, a calculated amount of water is poured into a metal evaporator cuvette 4 at the bottom of the chamber 1. The chamber 1 is sealed by closing the cover 2 and valves 6 and 8, then, opening the valve 12, vacuum to a residual pressure in the chamber of 10-60 kPa, and then turn on the heating to a temperature of 500-550 ° C. As water evaporates from the evaporator 4, the volume of the working chamber is filled with water vapor, which, due to its high heat capacity and thermal conductivity, ensures efficient heat transfer from the heated walls of the chamber 1 to the processed material. After equalizing the pressure in the chamber with the atmospheric outlet valve 6 is transferred to the open position and the excess steam is discharged mainly into the atmosphere (or into a previously evacuated receiver), preventing the increase in pressure above atmospheric.

The cessation of steam evolution from the outlet pipe indicates the heating of the hydrophobization chamber with the processed material to a predetermined temperature in the range of 500-550 ° C. The valve 6 is closed, stopping the discharge of steam into the atmosphere, and the chamber 1 is evacuated, opening the valve 12 and connecting it to the receiver 10, in which the residual pressure is 5-15 kPa. When the receiver volume is not less than the volume of the working chamber due to steam condensation in the receiver, the working volume of the hydrophobization chamber is effectively evacuated without hot gases entering the vacuum pump. With the reached values of temperature and pressure, the feedstock can withstand for 2-3 hours.

After that, the hydrophobization process is carried out by feeding liquid evaporator hydrophobizer into the evaporator 5 with the valve 8 open, which can be used as heavy and medium distillate oil products: diesel fuel, gas oil, used motor oil, and marine fuel oil. Mostly used medium distillate petroleum products, in the best case scenario - diesel fuel. The amount of sorbent required depends primarily on the volume of the working chamber and amounts to 0.3-0.6 g / l (chamber volume) depending on the fractional composition of the water repellent, on the amount and composition of the processed raw materials.

To ensure the complete evaporation of the hydrophobizator, heating while maintaining a temperature of 500-550 ° C is continued for another 5-20 minutes from the moment the hydrophobizer is fed. As a result of the vaporization of the water repellent, the pressure in the chamber 1 increases, the vacuum decreases to a residual pressure of 70-90 kPa. Then the heating is stopped and the chamber with the processed material is left to cool.

After cooling the hydrophobization chamber with the treated material to a temperature below 120 ° C (residual pressure of 30-40 kPa), air is introduced into the chamber and left until the temperature of the treated material is equal to the ambient temperature, then the resulting oil sorbent is unloaded.

The proposed method provides an oil sorbent with a dense and durable hydrophobic coating with high adhesion.

The experiments performed indicate a slight decrease in the sorption capacity of the sorbent after hydrophobic treatment, which is explained by a decrease in its porosity, filling open pores with a water repellent. However, when cleaning the aquatic environment, the untreated sorbent will predominantly absorb water, while low water absorption

The quality of the obtained hydrophobic coating allows tenfold regeneration of the sorbent treated in this way, which determines the main area of its application (if the strength of the aluminosilicate base allows) as a load in various devices for cleaning liquid media from oil products, where its use will be rational and most efficient .

The oil sorbent is regenerated using the same device as the hydrophobization of the initial porous aluminosilicate sorbent, while its processing technology includes the same operations and in the same sequence, with the only difference being that the spent oil sorbent is used as a raw material regeneration.

Examples of specific implementation of the method using the device

As a device for implementing the method used a modified drying cabinet ШС-635-5,5 with a working volume of 635 liters. Heater power 45 kW, maximum heating temperature 550 ° C, maximum vacuum 0.25 kPa. The standard cabinet is equipped with two nozzles with ball valves: one for supplying a water repellent, the other for venting steam installed in the upper part of the cabinet, and also a nozzle for a safety valve in the rear. A vacuum line is connected to the standard vacuum valve of the cabinet, connecting it to a 900 liter vacuum receiver. A rotary vane vacuum pump is connected to the receiver through a vacuum valve. The cabinet and receiver are equipped with manometers-vacuum gauges. Amount of the loaded material to 200 l.

Example 1

87 kg of expanded clay were taken and placed on 3 pallets with a bulk layer thickness of 40-60 mm. 0.8 L of water was poured into the evaporator cuvette. The receiver was pre-evacuated to a residual pressure of 10 kPa. The hydrophobization chamber was sealed and evacuated to a residual pressure of 40 kPa, after which the heating was turned on. The chamber was heated to a temperature of 550 ° C for ~ 2 hours; when t = 300 ° C was reached, water cooling of the chamber door was turned on to preserve the integrity of the seal, at a temperature of 310 ° C the pressure in the chamber was equal to atmospheric and further heating occurred with the steam valve open. When the hydrophobization chamber reached a temperature of 550 ° C, the achieved temperature was maintained for 3.0 hours. Then, the steam vent valve into the atmosphere was moved to the closed position and the hydrophobization chamber was evacuated into a previously prepared receiver to a residual pressure of 12 kPa. The valve on the vacuum line was closed, the valve for supplying the water repellent was opened. As a water repellent agent, diesel fuel in an amount of 350 ml was used, which was supplied to the evaporator. After the feed of the hydrophobizer, the temperature of 550 ° C was maintained in the chamber for 20 minutes, and then the heating was turned off and the chamber with the material was left to cool naturally. The residual pressure in the working chamber at the time the heating was turned off was 79 kPa. After 20 hours, the temperature in the working chamber was 113 ° C at a pressure of 45 kPa. They opened the valve on the steam outlet pipe and let air into the hydrophobization chamber. Then, after equalizing the temperature in the chamber with the ambient temperature (+ 20 ° С), the chamber door was opened for unloading the obtained oil sorbent.

Example 2

They took 16 kg of perlite and placed on 4 pallets with a bulk layer thickness of 40-60 mm. 500 ml of water was poured into the evaporator cuvette. The processing was carried out completely analogously to example 1 with differences in the values of some parameters. The hydrophobization chamber was sealed and evacuated to a residual pressure of 60 kPa. The material was heated to a temperature of 500 ° C for about 2 hours. At a temperature of 340 ° C, the pressure in the chamber reached atmospheric and a steam release valve was opened. Exposure after reaching a predetermined temperature of 500 ° C was carried out for 2.0 hours. As a water repellent agent, 400 ml of marine fuel oil F-5 in accordance with GOST 10585-2013 was introduced into the evaporator, after which the temperature was maintained for another 5 minutes, and then the heating was turned off. At the end of heating, the residual pressure in the working chamber was 88 kPa. After 20 hours, the temperature in the hydrophobization chamber was 82 ° C at a pressure of 34 kPa.

The sorption properties of the resulting oil sorbent were evaluated based on studies of the behavior of samples in aqueous and organic media.

The water absorption of the samples was determined according to GOST 8269.0-97 as follows: the studied samples of known mass were kept for 48 hours completely immersed in a vessel with water. After that, weighed, removing surface moisture.

Water absorption (W, mass%) was determined by the formula:

where m ₁ is the mass of the sample in a water-saturated state, g;

m is the mass of the sample in a dry state, g.

The sorption capacity (g / g) of the samples was determined in accordance with ASTM F: 726-12 gravimetrically by the mass difference between the initial and oil-saturated adsorbent at a test temperature of 22 ± 3 ° C and a relative humidity of 20-70%. A sample of known mass for 15 minutes was immersed in a test container filled with oil. After draining the excess oil, the mass of the absorbed substance was determined.

The results of the determination of water absorption and sorption capacity of the oil sorbent obtained by the proposed method according to examples 1 and 2 are shown in table 1.

The cleaning efficiency was determined on model systems simulating water pollution by diesel fuel. A known amount of diesel was placed on the surface of the water. Then, a layer of an adsorbent of a certain mass was uniformly applied to the oil product spot and kept until the adsorbent was completely saturated with oil. After that, the saturated adsorbent was removed and weighed after removing the oil from its surface.

Using a well-known technique, an analysis of a water sample was carried out on a KN-2m concentrator (SIBecopribor PEP, Russia) before and after extraction of the oil product with carbon tetrachloride using an EL-1 laboratory extractor (Sibecopribor PEP, Russia).

The mass concentration of petroleum product With _NP , mg / l in the sample of the analyzed water was calculated by the formula:

where C _ISM - mass concentration of oil in the eluate, measured on the device, mg / l;

- объем четыреххлористого углерода, использованного для проведения экстракции, мл;

- the volume of carbon tetrachloride used for the extraction, ml;

K is the dilution coefficient;

V - sample volume of the analyzed water, ml.

The degree of water purification S,% as a result of the adsorption process (the degree of extraction of NP from water) was estimated by the formula:

The results of the calculation of the cleaning efficiency are presented in table 2.

Claims (4)

1. A method of producing an oil sorbent, including drying a porous silicate material in a working chamber, processing it under reduced pressure with a gasified hydrocarbon hydrophobizer, followed by cooling to a temperature below the condensation temperature of the hydrophobizer, characterized in that the drying is carried out after evacuation of the working chamber to a residual pressure of 10-60 kPa in the atmosphere of superheated steam generated in the evaporator when the temperature in the chamber rises to 500-550 ° C, during which the pressure in the chamber is controlled, at this is prevented by its increase above atmospheric by venting the steam, after reaching the set temperature they maintain it for 2-3 hours, then venting the vapor into the previously evacuated receiver to a residual pressure in the working chamber of 10-20 kPa, introducing a water repellent into the working chamber in the liquid phase from calculation of 0.3-0.6 g per 1 liter of its volume, after which the temperature is maintained at 500-550 ° C for another 5-20 minutes, then the heating is turned off, the contents of the chamber are allowed to cool to a temperature below 120 ° C, they are allowed into the chamber air, leave it with the material until avnivaniya temperature to ambient temperature, whereupon unloading. 2. A device for implementing the method of producing a hydrophobic oil adsorbent, characterized in claim 1, which is a cylindrical chamber made with the possibility of sealing and evacuation and equipped with means for supplying a water repellent, characterized in that the chamber is installed horizontally and made with a sealed door-lid for loading and unloading of the sorbent and longitudinal internal ribs for placement of pallets with water-repellent material, is equipped in the upper part with a nozzle with a shut-off valve for start inside the liquid hydrophobizator from the tank placed outside and the evaporator for the hydrophobizator, and at the bottom - the cell-evaporator for water, as well as a nozzle with a shut-off valve for connecting a vacuum receiver with a volume exceeding the volume of the chamber equipped with a nozzle and shut-off valve for condensate discharge and equipped with a vacuum pump and vacuum gauge. 3. The device according to p. 2, characterized in that the hydrophobization chamber is equipped with an electric heating device, a thermocouple and is made with insulation. 4. The device according to p. 2, characterized in that the door-lid of the hydrophobization chamber is equipped with cooling means.

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