WO2010117292A1

WO2010117292A1 - Method for reducing the viscosity of heavy oil-bearing fractions

Info

Publication number: WO2010117292A1
Application number: PCT/RU2009/000167
Authority: WO
Inventors: Вячеслав Михайлович НЕКИПЕЛОВ; Петр Анатольевич КАЛИНИН
Original assignee: Nekipelov Vyacheslav Mikhailovich; Kalinin Petr Anatolievich
Priority date: 2009-04-08
Filing date: 2009-04-08
Publication date: 2010-10-14

Abstract

The invention relates to a method for processing heavy oil-bearing fractions and high-viscosity oil for bulk transportation by pipeline. The method involves carrying out the thermal cracking of heavy oil-bearing fractions at atmospheric pressure and at a temperature of 350-400°C in a cavitation zone to which a constant electric field with an intensity of 0.5-2.0 kV/cm is applied. The products of the vapour and liquid phases of thermal cracking are mixed in a buffer tank for bulk transportation. The invention makes it possible to reduce the viscosity of heavy oil-bearing fractions without the need for substantial energy expenditure using a low-temperature cracking mode, and to simplify the technical process of preparation for bulk transportation.

Description

A method of reducing the viscosity of heavy oily fractions

The invention relates to methods for processing heavy oil-containing fractions (fuel oil, used motor or lubricating oils, oil sludge, etc.) and highly viscous oil before transportation through pipelines, in particular, to methods for reducing their viscosity using thermal and physical methods of exposure.

The invention can also be used to increase the percentage of light hydrocarbons in crude oil. Reducing the viscosity of oil and oil products includes the problem of deep processing of oil-containing fractions in order to obtain an additional amount of light oil products. For these purposes, various methods of destruction or cracking are widely used.

A known method of catalytic cracking (patent US Ns 4468316), the main disadvantage of which is that the yield of light oil is limited by the activity and selectivity of the used catalysts.

In practice, another method for catalytic cracking of petroleum products has found application - the method of thermal decomposition of heavy oil fractions in the presence of a catalyst (M.G. Rudin, A.E. Drabkin, Oil refinery Quick Reference. P., Chemistry. 1980, p.70-73). The method includes heating the feedstock to a temperature of 470 ÷ 500 ° C at a static pressure of 0.06 ÷ 0.24 MPa, mixing it with water vapor, and then with a catalyst, processing the mixture in a reactor, followed by catalytic decomposition of the raw material and its separation into fractions, as well as the selection and regeneration of the catalyst at a temperature of 590 ÷ 670 ° C and a pressure of 0.06 ÷ 0.24 MPa. The disadvantage of this method is that the method is expensive due to the high heating temperature and difficult to implement due to the stage of catalyst regeneration.

A known method of refining petroleum products by exposing them to ionizing radiation (neutron flux or γ-radiation), followed by catalytic cracking of the impact products (patent RU N ^Q 2100404).

The application of the method is difficult in industrial production due to the complexity of process control. In addition, the method is not safe to use.

A number of mechanical methods for reducing the viscosity of oil are known, according to which mechanical hydrodynamic cracking is caused by intensive mixing (application RU Ns 2005107526), in particular using a centrifugal pump (patent RU Ns 2304607). To enhance the efficiency in the hydrodynamic treatment zone, oil is subjected to pressure with a constant axial component and a variable transverse shear component (patent RU Ns 2325432).

The viscosity of the oil treated by such methods can be reduced to

125 MPa-s at a temperature of (20 ± 5) ° C, while untreated oil at the same temperature usually has a viscosity of (320 ÷ 330) MPa s.

The disadvantages of the methods include an insufficiently high increase in the content of light petroleum products, which determines the reversibility of changes in viscosity, i.e. oil viscosity is restored over time. So, it is known that after the processing of petroleum feedstock by machining it in a dispersive hydrodynamic rotary pulsation apparatus (patent RU Ns 2102434), in which petroleum feedstock is subjected to shock-cavitation, the yield of light petroleum products boiling up to 35O ⁰ C increases only by 2.4 ÷ 4.1 macc.%.

The creation of a cavitation zone for cracking is the most promising direction for the deep processing of heavy oily fractions. From the publications (US Pat. No. 5,969,207, UA Pat. No. 81479), mechanical devices are known to allow cavitation processes for cracking.

The disadvantages include the fact that the effectiveness of qualitative and quantitative changes in the composition of a mixture of liquid hydrocarbons depends on the number of cavitation bubbles per unit volume.

This indicator is limited by the fact that the narrowing in the cross section of the fluid flow, i.e. hydrodynamic resistance, therefore, the intensification of cavitation processes has a limit for economic reasons.

There is also known a method of vortex cracking of oil and oil products (patent RU Ns 2305699), including the separation of oil and oil products into fractions by feeding them with an oil pump to a vortex hydro-cavitation installation.

The main disadvantage of this method is that processing in a hydro-cavitation installation of heavy oil-containing fractions requires at least 10 cycles, while the flow is subjected to a pressure of more than 70 atm., These circumstances reduce the economic efficiency of processing.

A number of methods are known for processing heavy oil-containing fractions in which a cavitation zone is created using the wave action of a wide spectrum of frequencies.

In the method of processing fuel oil by vacuum distillation to obtain distillate fractions (patent SU Ns 1377281), the liquid phase of the bottom residue is affected by acoustic vibrations with a frequency of 0.1 ÷ 200 KHz and a power of 0.2 ÷ 3 W / cm ² at a residual pressure of 20 ÷ 200 mmHg.

The disadvantages of the method include the high energy costs of creating a deep vacuum, and the use of only the acoustic frequency range does not provide reliable destruction of highly viscous media, it requires a long period of time for processing fuel oil. In addition, this method is intended for processing only fuel oil and does not allow processing, for example, used motor or lubricating oils.

A known method of processing oil, oil products, hydrocarbons (patent RU N ° 2149886) by exposure to a modulated flow of sound energy with a frequency of 1-I - 10 ⁶ Hz, a power of 0.1 ÷ 150 kW / cm ² uniformly distributed over the cross section of the processed fluid stream.

The disadvantage of this method is that its implementation is limited to the conversion of low molecular weight n-alkanes to cycloparaffins.

There is also known a method that includes ultrasonic treatment of liquid raw materials in a closed circulation circuit with a radiation intensity of 1 ÷ 10 MW / m ² . In this case, simultaneously with the raw material, a substance is provided in the processing zone to ensure its dispersion in an amount of 0, 1 ÷ 80 vol.% And the static pressure is maintained in the range from 0.2 to 5 MPa (patent RU N ^Q 20781 16). The processed raw material enters the device for separating the raw material into liquid and vapor phases, where it is heated to 470 ÷ 500 ° C at a static pressure of 0.06 ÷ 0.24 MPa, the vapor phase enters the device for condensation of the final product. This method allows you to extract 54-78% of light petroleum products. Apparatuses and devices for ultrasonic processing of liquid raw materials are widely represented in patent documents, for example, (EP 0009687, WO 9410261 and patent RU Ns 2151165). This method has a number of technological disadvantages: it is carried out at high temperatures and pressures, and, therefore, energy-intensive; difficult to implement because the installation for implementing the specified method of cracking petroleum products contains a number of interconnected devices and devices; processing of raw materials in a closed cycle limits the possibility of intensifying the process of obtaining final products.

A known method of cracking oil and petroleum products (application RU Ns 20001 13664), including stationary heating of raw materials to temperatures evaporation of light fractions (not more than 35O ⁰ C) at a pressure in the reactor of not more than 0.2 MPa, followed by processing of the raw materials with pulsed optical radiation with a radiation pulse duration of not more than 1 s, a radiation wavelength in the range of 0.1-15 microns, radiation power providing a concentration of energy in the absorbing layer of not more than 300 kJ / kg of raw material in each pulse, for the time necessary to obtain a given number of light fractions, the vapors of which are then condensed.

The disadvantage of this method is the high energy costs in the industrial processing of heavy oily fractions in large volumes.

Ways of using electric current have been developed both for activating the processed raw materials and for cracking heavy oil products. The company Elastromagetis Epergu Sorroratiop developed a physical method of processing (US patent NQ 5055180) by sequential extraction of fractions from hydrocarbons using electromagnetic energy with a frequency of 300 MHz ÷ 300 GHz.

The disadvantage of this method is that the yield of light petroleum products is not high enough and depends on the intensity of the electromagnetic field.

It is known that the application of an electric field (application US 2008257414) with a voltage of 6-10 kV / cm for 60 seconds. allows you to reduce the viscosity of heavy oily fractions by 17 ÷ 20%, however, after 30 minutes the viscosity is restored by half, and after 8 ÷ 10 hours completely, which limits the application of the method for preparing high-viscosity oil products for transportation through pipelines.

When studying the destruction of hydrocarbons in the cavitation region in the presence of an electric field when activated with aqueous solutions of electrolytes (A.S. Besov, K.Yu. Koltunov, S.O. Brulev, V.N. Kirilenko, S.I. Kuzmenkov, E. I . Palchikov. Letters in ZhTF, 2003, volume 29, issue 5, pp. 71-77) it was established that the imposition of a strong of an electric field with a strength of 10 ÷ 20 kV / cm on the cavitation zone created by the action of ultrasonic vibrations intensifies the cavitation process and allows additionally obtaining 1.5 ÷ 2.0% of light oil products for 10 minutes. The disadvantage of this method is that the intensification of the cavitation process is limited by the accumulation inside the cavitation bubbles of light cracking products, which leads to an increase in saturated vapor pressure and thereby complicates the emergence of new electric discharges. This also explains the need to create an electric field of relatively high intensity. The second drawback is that the authors used an aqueous electrolyte solution to form a stable volume discharge in the cavitation region.

Known methods for electrochemical cracking of heavy petroleum products under the influence of electric current.

So, according to the description of the method of electrochemical cracking of heavy oil products (patent RU 2333932) under the influence of electric current, the process is carried out at an excess pressure of 0.01-0.5 MPa and a temperature of 380-450 ° C, in the presence of metal alloys Al, Cr, Ni, Fe, which are used as separate conductors installed in the cracking zone in contact with the raw material, through which an electric current e of 0.1-10 kV voltage and a current value of 1-1 -10 ⁴ A is passed. As a result of electrochemical cracking reactions, they are released from the raw material diesel oil fractions in the form of vapors. The same effect is caused by the placement in the cracking zone of two electrodes separated by a layer of solid dielectric material (patent AU NQ 4085000).

The disadvantage of the methods is the high degree of contamination of the cracked products with materials of destruction of the electrodes due to the occurrence of electrochemical reactions on the surfaces of these electrodes.

A known method of decomposition of organic compounds (patent RU Ns 2246525), including simultaneous or sequential the impact on the destructible raw materials with electromagnetic wave and acoustic fields with energy and frequencies corresponding to the resonant frequencies and / or the vibration frequency of the molecules of the degradable organic compounds and / or compounds with subsequent temperature exposure within the limits of atmospheric distillation. It is also known (see WO 0231084) that the resonant frequency is selected by a set of coils mounted on a transport pipeline coaxially to the feed stream.

The disadvantage of this method is that the activation is carried out as a separate preparatory operation, and the electromagnetic power indicated in the examples, equal to 7 W, is too small to affect cavitation processes.

Closest to the claimed method in its technical essence, as well as in the achieved effect, is a method for the thermal processing of heavy oil-containing fractions (patent RU NQ 2215775) (prototype), including thermal cracking of heavy oil-containing fractions into phases and obtaining final products from the vapor phase, moreover , before thermal cracking, the feedstock is preliminarily subjected to a wave action in a separate processing zone by forming a wide spectrum of frequencies from acoustic light range, after which the products influence supplied to the thermal cracking, which is carried out in the mode of oil primary distillation at atmospheric pressure and a maximum heating temperature of 36O ⁰ C. A wide range of acoustic frequencies up to the range of the light emitter is achieved by combining the acoustic vibrations with the generator of electromagnetic vibrations. Electromagnetic vibrations are modulated by a microwave spectrum, which is accompanied by the formation of an additional front of an elastic acoustic wave. The method allows to decompose fuel oil brand M-100 into final products of the composition: diesel fraction - 60%; bitumen of road brands - 40%. The viscosity of the mixture of the final products, according to our estimation, can be 55 mm ² / s at a temperature of (20 ± 5) ° C. The disadvantages of the prototype include the fact that the activation is carried out in a separate working capacity, which does not allow at the cracking stage to affect the qualitative and quantitative characteristics of the final products. In addition, the selectivity of the front impact of an elastic acoustic wave on the feedstock of a certain fractional composition is achieved by selecting the material of the antenna plates and the dielectric body of the emitter of acoustic vibrations, which complicates the hardware design of the technological process.

The invention is aimed at finding a method for the reagent-free reduction of the viscosity of heavy oil-containing fractions, as well as at reducing energy costs and simplifying the process of preparing oil-containing fractions for main transportation through pipelines.

The technical result is achieved by the fact that a method for reducing the viscosity of heavy oil-containing fractions is proposed, which consists in thermal cracking of heavy oil-containing fractions at atmospheric pressure and a temperature of 350 ÷ 400 ° C, at which a cavitation zone is created directly in the apparatus for performing thermal cracking, on which a constant an electric field with a strength of 0.5 ÷ 2.0 kV / cm, then the products of the vaporous and liquid phases of thermal cracking are mixed.

The indicated result is also achieved by the fact that the cavitation zone is created by the acoustic effect of the oscillations of the ultrasonic frequency spectrum. It is possible that the cavitation zone is created by hydrodynamic action on the flow of heavy oil-containing fractions.

It is advisable that a constant electric field is applied by immersing into the cavitation zone a system of steel mesh heterogeneous electrodes twisted into a roll with a distance between them of 1 ÷ 2 cm.

Under the influence of an electric field, gas electric discharges occur in the cavitation bubbles formed. This is due to the fact that with the formation of a cavitation bubble the pressure in it does not exceed the saturated vapor pressure of the surrounding liquid. In the case of heavy oil fractions, this pressure can be so small that gas discharge conditions are realized even at relatively small values of the electric field of 0.5 ÷ 2.0 kV / cm.

The formation of a gas discharge leads to two beneficial effects. First of all, during a gas discharge, an electrodynamic shock occurs, as a result of which hydrodynamic waves propagate in the medium of heavy oil fractions, which in turn lead to the formation of new cavitation bubbles. An increase in the concentration of cavitation bubbles occurs and the mechanochemical activity of the cavitation area as a whole increases.

It is important to note that the accumulation of light vaporous cracking products in the environment of heavy oil fractions leads to an increase in the pressure of saturated vapors inside cavitation bubbles, thereby complicating the occurrence of electric discharges and inhibiting the cracking process. Therefore, the constant removal of vaporous fractions from the reaction zone is essential. This is achieved by placing a cavitation zone and a device for its electrical activation directly in the means for thermal cracking. The declared temperatures of 350 ÷ 400 ° C correspond to the known parameters of low-temperature cracking.

The proposed method for processing heavy oily fractions is as follows.

From the buffer storage tank, the feedstock, heated by an external heater to a reaction temperature of 35O ⁰ C, is continuously fed through the inlet pipe into the means for performing thermal cracking at a rate that ensures that a separate allocated volume of feedstock stays in it for at least ten minutes. The specified tool is also equipped with a device for maintaining the temperature of the working environment within 350 ÷ 400 ° C. In the apparatus for performing thermal cracking under the action of an ultrasonic generator, for example, the FinnSonic FSG-482 brand (http://finnsonic.ru), a cavitation zone is created. When creating a cavitation zone by hydrodynamic influence, the feed stream is fed into the means for thermal cracking through a hydrodynamic cavitator, made, for example, according to the UA patent

A system of steel mesh heterogeneous electrodes immersed in a roll with a distance between them of 1 ÷ 2 cm immersed in the cavitation zone is applied with a constant electric field of magnitude, which ensures the creation of tension between these electrodes in the range of 0.5 ÷ 2.0 kV / cm. The electrodes can be made as in the known utility model (patent RU Ns 74917).

As a result of cracking in the activated cavitation zone, light hydrocarbon fractions are formed, which then evaporate and in a vapor state enter the reflux condenser, where the vapor is condensed using a refrigerator. The streams of condensed light hydrocarbon fractions released as a result of cracking of heavy oil-containing fractions (vapor phase cracking), as well as the streams of heavy hydrocarbon fraction with a boiling point above 400 ⁰ C (liquid cracking phase), are directed to various storage tanks and then products of vapor and liquid thermal cracking phases are mixed in a buffer tank for trunk transportation through pipelines.

The pressure in the thermal cracker is maintained at 0.1 MPa by a pressure valve installed on the vapor phase cracking line.

The residence time of each individual volume of heavy oil-containing fractions in the cavitation zone is determined by the thermodynamic characteristics of low-temperature cracking, in which the effective separation of the cracked products into vapor and liquid phases occurs in 10– ^; 25 minutes A mixture of products of vaporous and liquid cracking phases with a viscosity of not more than 50 mm ² / s at a temperature of (20 ± 5) ° C and with a content of light fractions of at least 60 mass% in the mixture is obtained.

The implementation of the proposed method is illustrated by specific examples. The examples illustrate but do not limit the proposed method.

Example 1

As a heavy oil-containing fraction, fuel oil of the M-100 brand of the Moscow Oil Refinery, low ash, without mechanical impurities, with the following passport data was used: mass fraction of water 0.4%, mass fraction of sulfur 2.39%, pour point 13 ⁰ C, density at 2O ⁰ C 983.0 kg / m ³ , viscosity 71 mm ² / s at 8O ⁰ C. Fuel oil was fed into a thermal cracker, at which the temperature was maintained at 36O ⁰ C. The 30 kHz oscillations generated by the FippSopis FSG ultrasonic generator -482, created a cavitation zone, on which imposes an electric field strength of 0.5 kV / cm. The residence time of each individual volume of fuel oil in the cavitation zone was 12 minutes.

The yield of the final product in composition: vapor phase - 61 mass% with a boiling point of 140 ÷ 360 ° C; the liquid phase is 39 mass% in the form of petroleum products similar in composition to the raw materials used for the preparation of road grade bitumen. The viscosity of the mixture of products of vapor and liquid cracking phases was 50 mm ² / s at a temperature of 20 ⁰ C. Examples 2-5.

According to Example 1, differ in the values of the temperature in the reactor and the electric field strength.

Example 6

Timan-Pechersky oil and gas basin oil with a viscosity of 1221 mm ² / s at 2O ⁰ C was used as a heavy oil-containing fraction. The oil was fed to a thermal cracker, at which the temperature was maintained at 36O ⁰ C. By the influence of oscillations with a frequency of 30 KHz generated by an ultrasonic generator FinnSonic FSG-482, created a cavitation zone on which an electric field of 1 kV / cm was applied. The residence time of each individual volume of fuel oil in the cavitation zone was 12 minutes.

The yield of the final product in composition: vapor phase - 75 mass% with a boiling point of 140 ÷ 360 ° C; the liquid phase is 25 mass% in the form of petroleum products similar in composition to the raw materials used for the preparation of road grade bitumen. The viscosity of the mixture of products of the vaporous and liquid cracking phases was 33 mm ² / s at a temperature of 2O ⁰ C.

Examples 7.8.

According to Example 6, differ in temperature values in the reactor.

All Examples are summarized in the Table: "Achieving the claimed result with various processing parameters of heavy oily fractions." The temperatures in the table in the apparatus for cracking are shown to coincide with the temperatures of the end of boiling of the vapor phase.

Table

Achieving the claimed result with various processing parameters of heavy oily fractions

The present invention allows, without significant energy costs, in the mode of low-temperature cracking, to reduce the viscosity of heavy oil-containing fractions and to prepare oil-containing fractions for main transportation through pipelines.

The invention can also be used to increase the percentage of light hydrocarbons in crude oil.

Claims

Claim

1. A method of reducing the viscosity of heavy oily fractions, which consists in thermal cracking of heavy oily fractions at atmospheric pressure and a temperature of 350 ÷ 400 ° C, in which a cavitation zone is created directly in the apparatus for performing thermal cracking, on which an additional constant electric field of 0.5 ÷ 2.0 kV / cm. Then the products of the vapor and liquid phases of thermal cracking are mixed in a buffer tank for trunk transportation through pipelines.

2. The method according to claim 1, characterized in that the cavitation zone is created by acoustic exposure to vibrations of the ultrasonic frequency spectrum.

3. The method according to claim 1, characterized in that the cavitation zone create a hydrodynamic effect on the flow of heavy oil-containing fractions.

4. The method according to claim 1, characterized in that a constant electric field is applied by immersing into the cavitation zone a system of steel mesh heterogeneous electrodes twisted into a roll with a distance between them of 1 ÷ 2 cm