RU2626240C1 - Method of processing sulfur-containing oil sludge with high water content - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: method for processing a sulfur-containing oil sludge with a high water content involves premixing the oil sludge with a hydrocarbon solvent, activating the product produced by exposing the latter to electromagnetic radiation with a frequency of 40-55 MHz, a power of 0.2-0.6 kW, with an activation time of 1-8 hours and a temperature of 40-70°C, separating the hydrocarbon, aqueous and solid phases from the activated product, distilling the hydrocarbon solvent from the hydrocarbon phase, and carrying out the hydrocracking produced by stripping the hydrocarbon component in the presence of the zeolite-containing catalyst at a temperature of 400-500°C, a hydrogen pressure of 50-100 atm, for 2.0-3.0 hours to produce the desired oil.

EFFECT: producing the target petroleum product with low sulfur content.

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Description

The invention relates to the field of oil refining and petrochemicals, in particular to methods for processing sulfur-containing oil sludge with a high water content to obtain products having a low sulfur content, and can be used in the oil and oil refining industry.

Oil sludge are complex physicochemical mixtures, which consist mainly of oil products, solids (clay, metal oxides, sand) and water. The ratio of the components of oil sludge can be very different. In particular, the term "oil sludge" means oil with a petroleum product content of up to 90 wt%, water up to 90 wt%, and solid matter up to 20 wt%.

Sulfur-containing oil sludge - a highly toxic product that pollutes all layers of the biosphere, is the cause of serious environmental problems.

In this regard, the problem of processing and disposal of sulfur-containing oil sludge is currently very acute.

Numerous methods are known for the processing of oil sludge based on the separation of sludge into its constituent components and their subsequent conversion. The choice of a particular processing scheme is dictated by the characteristics of the initial sludge and the requirements for the resulting target products.

A known method of processing oil sludge, in accordance with which the oil sludge is treated with a demulsifier, heated to 40-50 ° C and defended with its separation into oil and water phases, water-sludge suspension and oiled mechanical impurities. The oil product phase is used as boiler fuel, the aqueous phase is removed and sent to the bottom sediment to be washed into the sludge collector, the water-sludge suspension is used as a nutrient medium for growing microorganisms, and the oiled mechanical impurities, after washing with solvent and water vapor, are introduced into the water-sludge suspension with grown by microorganisms, at a temperature of 30-35 ° C for 2–3 days they are neutralized under aerobic conditions and purified mechanical impurities are removed (RU 2116265, 1998). The disadvantages of this method are the complex technology of its implementation, in particular, the presence of a laborious stage of growing microorganisms, a high sulfur content in the target products, the need for regeneration of the solvent used.

There is a method of processing solid sludge by separate selection from the storage barn of the upper layer of sludge and the bottom layer of oil sludge, in which oiled soil is separated from the bottom layer of oil sludge, which is sent to a landfill for biodegradation or used as insulation material at landfills for household and industrial waste. The bottom layer of oil sludge is combined with its upper layer or modified by dilution with a fraction of light oil products. Oil sludge prepared in this way is sent to a heat exchanger, superheater and then under pressure into a shower, upon exiting which it is sprayed. Flue gases move upstream to the oil sludge from the bottom up. In this case, the sludge is heated from a temperature of 120-140 ° C at a heating rate of 143 ± 15 ° C / s. Then, heating is carried out in a certain way and, at the final heating stage, the temperature is maintained at 340-350 ° C and the heating rate is 10 ± 2 ° C / s. The selection of oil fractions is carried out at the final stage of heating. As a result of the separation of oil fractions, tar for road bitumen is obtained, a fraction of light oil products, which is used as heating oil or as an additive to hydrotreating raw materials at oil refineries (RU 2506303, 2014).

The disadvantage of this method lies in its complex technological scheme, obtaining petroleum products having a high sulfur content.

A known method of processing oil sludge described in RU 2550843, 05.20.2015. According to the specified method, the initial oil sludge is subjected to separation into oil concentrate, oil-contaminated water and mechanical impurities. Oil-contaminated water is subjected to purification with obtaining normatively pure water, mechanical impurities are processed into road-building materials. The oil concentrate in the presence of a diluent and stabilization vapors is refined to obtain a feed which is subjected to thermal conversion to obtain a diluent, light fractions, residual fraction and hydrogen sulfide-containing gas. The diluent is sent to dilute the oil concentrate. The light fractions are subjected to hydrostabilization and stabilization to obtain light marketable products, for example, technical gasoline and distillate marine fuel. The residual fraction is withdrawn as a heavy boiler fuel. Hydrogen sulfide-containing hydrocarbon gas is purified from hydrogen sulfide, for example, to produce sulfur and fuel gas used for own needs. In this case, in particular, the unit for the post-treatment of the oil concentrate can be, for example, a separation unit with units for coalescence filtering and mixing the oil concentrate with a diluent and stabilization vapors. The hydrostabilization and stabilization unit of the light fractions is a unit for the shallow catalytic hydrogenation of light fractions on a nickel-containing catalyst connected to a packed or plate-shaped stabilization column. The gas hydrogen sulfide purification unit is, for example, an amine purification unit, a chelate purification unit, a Klaus unit, or one of the other known plants, the appropriateness of which is determined depending on the content of hydrogen sulfide in the gas, its mass flow rate and the requirements for the quality of gas purification. A thermal conversion unit for oil concentrate, including equipment for fractionation, can be, for example, a thermal cracking unit, which includes a distillation column for thermolysis vapors.

The disadvantage of this method lies in its complex technological scheme.

Closer to the invention is a method of processing oil sludge isolated from bottom sediments of buffer ponds of biological treatment facilities (I.M. Kolesnikov, V.I. Frolov, XX Borzaev, A.P. Glotov, S.V. Kardashev / Mathematical modeling of catalytic cracking oil sludge subjected to electromagnetic activation / HTTM, No. 6, 2015, p. 16-20).

The oil sludge of JSOC Bashneft-Ufaneftekhim, which is a mixture of the oil component (30.1% of the mass) of water (51.8% of the mass) and mechanical impurities (18.1% of the mass), is mixed with carbon tetrachloride in the ratio of carbon: oil sludge equal to 1: 1. After stirring, the mixture is left to stand for 8 hours with the formation of two layers: the upper solution of oil in carbon tetrachloride and the lower - water and mechanical impurities. The upper layer is separated from water and solids, then the residual amount of solids is filtered from it. Carbon tetrachloride and residual water are distilled off from the filtrate. The resulting oil sludge with a water content of 1.8% of the mass, sulfur 2.03% of the mass, solids 1.14% of the mass, oil component n.k. 83.5 ° C, c.k. 680.4 ° C - the rest is subjected to activation by the action of high-frequency radiation with a frequency of 40-55 MHz with a power of 0.2-0.6 kW.

Activated oil sludge is subjected to catalytic processing in the presence of high-silica zeolite-aluminosilicate cracking catalysts.

The specified method allows to increase the yield of light fractions by 11-16% of the mass. depending on cracking temperature. The disadvantage of this method of processing oil sludge is the great difficulty in separating the aqueous, hydrocarbon and solid phases before the activation of the feedstock due to the formation of emulsions, which require additional processing for their destruction. Such processing leads to large time and material costs. The resulting target product has a sulfur content of 0.7% by weight.

Thus, the known method is not effective enough.

The objective of the described invention is to increase the efficiency of the method of processing sulfur-containing oil sludge with a high water content.

The problem is achieved by the described method of processing sulfur-containing oil sludge with a high water content, including preliminary mixing of the oil sludge with a hydrocarbon solvent, activation of the resulting product by exposure to the latter with electromagnetic radiation with a frequency of 40-55 MHz, power 0.2-0.6 kW, with activation duration 1 -8 h and a temperature of 40-70 ° C, separation of the hydrocarbon, aqueous and solid phases from the activated product, distillation of the hydrocarbon solvent from the hydrocarbon phase and conducting hydrocracking obtained by distillation of a hydrocarbon component in the presence of a zeolite-containing catalyst at a temperature of 400-500 ° C, a hydrogen pressure of 50-100 atm, for 2.0-3.0 hours to obtain the target oil product.

Achievable technical result is to obtain the target product with a low sulfur content.

The essence of the described method is as follows.

As a feedstock in the described method, it is possible, in particular, to use sulfur-containing oil sludge from storage barns, oil-containing bottom sediments of buffer ponds of biological treatment plants and other similar raw materials with a high water content. In the framework of this application, the term "high" means the water content in the original sludge more than 10% of the mass.

The feedstock is mixed with an organic solvent, preferably in a weight ratio of raw material: organic solvent, equal to 1: 1-10: 1. As an organic solvent, it is possible to use, in particular, toluene, hexane, carbon tetrachloride.

The product formed by mixing is activated by exposure to the latter with electromagnetic radiation at a frequency of 40-55 MHz, a power of 0.2-0.6 kW for 1-8 hours and a temperature of 40-70 ° C. The hydrocarbon, aqueous and solid phases are separated from the activated product. Then the organic solvent is distilled off from the hydrocarbon phase and the hydrocarbon component obtained by distillation is subjected to hydrocracking in the presence of a zeolite-containing catalyst. The organic solvent is recycled. Hydrocracking is carried out at a temperature of 400-500 ° C, a hydrogen pressure of 50-100 atm, with a volume ratio of raw materials: hydrogen of 1: 400-2000, for 2.0-3.0 hours. To obtain the target oil from the hydrocracking product, hydrogen and hydrocarbon gases are separated. The residue highlighted in this case is the target oil product - a wide liquid fraction of hydrocarbons (NK 44-60 ° C, KK - 360-420 ° C).

As a zeolite-containing catalyst during hydrocracking, it is possible to use such zeolite-containing hydrocracking catalysts as, for example, SGK-5, Ni-W / SBA-15 / beta, Ni-W / TUD / beta, Ni-W / SBA-15 / MFI.

The target product has a low sulfur content and can be used to produce gasoline and diesel fuel in accordance with the requirements of the Technical Regulations of the Customs Union (TP TS 013/2011). The resulting solid phase is a mechanical impurity that can be used in the production of road-building materials. The separated aqueous phase is water with a low content of impurities and can be used as technical.

The ability to obtain the target product with low sulfur content is achieved through the activation process of sulfur-containing feedstock with a high water content. Preliminary electromagnetic processing of the feedstock under the above conditions leads to more efficient activation of the feedstock due to the presence of water. Water, unlike other liquids, is a system characterized by strong intermolecular bonds (hydrogen bonds) with the formation of conglomerates of hundreds of molecules and an infinite number of possible forms. These conglomerates have a lot of different vibrations and form a large number of natural frequencies. Such a frequency spectrum is a physical copy of the geometric structure of water and undergoes characteristic changes during the external wave action. The features of the physical properties of water and the numerous short-lived hydrogen bonds between adjacent hydrogen and oxygen atoms in a water molecule create favorable opportunities for the formation of special structure-associates of clusters), which more effectively perceive, store and transmit wave energy to oil sludge hydrocarbons.

The invention is illustrated below by non-limiting examples.

Example 1

As the feedstock, the oil component is used (bp - 83.5 ° C, bp - 680.4 ° C, total sulfur content - 2.03% wt., Water - 1.8% wt., mechanical impurities - 1.14% by mass), isolated from oil sludge - bottom sediments of buffer ponds of biological treatment facilities (saturated hydrocarbons - 20.9% by mass, water 69% by mass, mechanical impurities - 10.1% by mass .). The oil component of the sludge is subjected to hydrocracking in an autoclave on an industrial catalyst SGK-5 (TU 2177-006-46693103-2004 with amendment 1). The specified catalyst is a granule consisting of high-silica zeolite of the pentasil group, aluminum oxide and hydrogenating components (mass fraction of hydrogenating components in terms of calcined at 550 ° C,% of the mass is: molybdenum trioxide 10-12, nickel oxide 5-6). The hydrocracking process is carried out at a temperature of 400 ° C and a hydrogen pressure of 70 atm (volume ratio of feed: hydrogen is 1: 2000) for three hours. The desired petroleum product is separated from the hydrocracking product. The target oil product is cooled, the fractional composition is determined by the method of simulated distillation using a Kristalyuks 4000M gas chromatograph with a flame ionization detector, and the product is analyzed for the total sulfur content by X-ray fluorescence method on a Spectroscan SL instrument. The target oil contains 0.1% of the mass. sulfur.

Example 2

As the feedstock, the oil component is used (bp - 83.5 ° C, bp - 680.4 ° C, total sulfur content - 2.03% wt., Water - 1.8% wt., mechanical impurities - 1.14% mass.), isolated from bottom sediments of buffer ponds of biological treatment facilities (saturated hydrocarbons - 20.9% mass, water 69% mass., mechanical impurities - 10.1% mass). The oil component of the oil sludge is activated by exposure to the latter with electromagnetic radiation at a frequency of 45 MHz, power 0.3 kW, at a temperature of 60 ° C, atmospheric pressure and a treatment time of 3 hours and subjected to hydrocracking in an autoclave on an SGK-5 catalyst, at a temperature of 400 ° C and a hydrogen pressure of 70 atm (volume ratio of feed: hydrogen 1: 2000) for three hours. After the separation of hydrogen and hydrocarbon gases from the hydrocracking product, the target oil product is obtained. The target oil product is cooled, the fractional composition is determined by the method of simulated distillation using a Kristalyuks 4000M gas chromatograph with a flame ionization detector, and the product is analyzed for the total sulfur content by X-ray fluorescence method on a Spectroscan SL instrument. The target oil product has a sulfur content of 0.06% of the mass.

Example 3

Oil sludge is used as a feedstock - bottom sediment of buffer ponds of biological treatment facilities containing an oil component with a sulfur content of 2.0% by mass - 30.1% by mass, water - 51.8% by mass and mechanical impurities - 18.1% by mass. The original petroleum sludge is mixed with toluene in a mass ratio of sludge: toluene equal to 1: 1, and stirred for 1 h at 8000 rpm. The resulting product is subjected to activation by applying electromagnetic radiation at a frequency of 45 MHz, power 0.3 kW, at a temperature of 60 ° C, atmospheric pressure and a processing time of 3 hours. The activated product is then incubated for 1 hour and separated into hydrocarbon, water and solid. phase. Then, toluene is returned from the hydrocarbon phase, which is returned to the process cycle. The hydrocarbon component obtained by distillation is subjected to hydrocracking on an SGK-5 catalyst at a temperature of 400 ° C and a hydrogen pressure of 70 atm (volume ratio of feed: hydrogen is 1: 2000) for three hours to obtain, after separation of hydrogen and hydrocarbon gases, the target oil product. The selected target oil product is cooled, the fractional composition is determined by simulated distillation on a Kristallux 4000M gas chromatograph with a flame ionization detector, and the product is analyzed for total sulfur content by X-ray fluorescence method on a Spectroscan SL instrument. The target oil product (NK 44 ° C, KK 420 ° C) has a sulfur content of 0.03% of the mass.

From the above examples, it follows that the method using the hydrocracking process of inactive oil sludge with a low water content can reduce the sulfur content in the target product to 0.1% of the mass. (example 1), carrying out the method using the hydrocracking process of oil sludge with a low water content, subjected to pre-activation, can reduce the sulfur content to 0.06% of the mass. (example 2), the method using the hydrocracking process of activated oil sludge with a high water content can reduce the sulfur content in the target product to 0.03% of the mass (example 3).

Thus, the implementation of the method using the activation of the feedstock - sulfur-containing oil sludge with a high water content and subsequent hydrocracking of the activated hydrocarbon component under the above conditions can significantly reduce the sulfur content in the target product (two times) in comparison with the method using the activation of the feedstock - sulfur-containing oil sludge with a low water content and subsequent hydrocracking, which is an unexpected result. In addition, the activation of the feedstock by electromagnetic radiation with a frequency of 40-55 MHz, power 0.2-0.6 kW, at a temperature of 40-70 ° C, atmospheric pressure and a processing time of 1-8 hours also leads to a more efficient separation of the above activated product into the aqueous, hydrocarbon and solid phases and, as a result, to reduce material, energy and time costs for separation.

Carrying out the process under other conditions of activation and hydrocracking included in the declared intervals of operating conditions leads to similar results, violation of these conditions does not allow to achieve the desired result.

Thus, the described method allows to obtain the target product having a low sulfur content, which determines the possibility of further processing of the specified product to commercial gasoline and diesel fuel of high quality in milder technological conditions.

Claims (1)

 A method of processing a sulfur-containing oil sludge with a high water content, including pre-mixing the oil sludge with a hydrocarbon solvent, activating the resulting product by exposure to the latter with electromagnetic radiation at a frequency of 40-55 MHz, a power of 0.2-0.6 kW, with an activation duration of 1-8 hours and temperature 40-70 ° C, separation of the hydrocarbon, aqueous and solid phases from the activated product, distillation of the hydrocarbon solvent from the hydrocarbon phase and carrying out hydrocracking obtained by distillation of the carbohydrate native component in the presence of a zeolite-containing catalyst at a temperature of 400-500 ° C, a hydrogen pressure of 50-100 atm, for 2.0-3.0 hours to obtain the target oil product.