RU2794323C1 - Oil treatment method - Google Patents

Abstract

FIELD: oil processing.

SUBSTANCE: invention relates to methods for processing oil and can be used at the facilities of the petrochemical, oil and gas processing, oil and gas industry. The invention relates to a method of processing oil, in which oil is fed into a mixer, in the spiral chamber of which a turbulent vortex motion is created by the oil flow with the formation of a cavitation cavity in the central part of the spiral chamber, where oil is processed by hydrodynamic vortex cavitation. The mixer is supplied with oil heated to a subcritical temperature, at which the oil does not yet boil until the formation of bubbles, at the same time the mixer speed controller, made in the form of a rotary blade installed at the inlet to the spiral chamber with the possibility of fixing it in a given position, is used to regulate oil supply rate in the range from 48 to 53 m/s until the formation of a stable cavitation cavity.

EFFECT: increase in the quality of oil for its subsequent processing by breaking the integrity of molecular chains and breaking bonds between individual parts of molecules.

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Description

The invention relates to methods for processing oil and can be used at the facilities of the petrochemical, oil and gas processing, oil and gas industry.

From the prior art there is a method of processing oil, implemented using a jet mixer, which consists in the fact that oil is fed into the mixer, in the spiral chamber of which a turbulent vortex motion is created by the oil flow with the formation of a cavitation cavity in the central part of the spiral chamber, where the oil is processed by hydrodynamic vortex cavitation (see Patent RU 2309790, publ. 11/10/2007).

The disadvantage of this method is weak cavitation, the creation of developed cavitation can cause erosion of the sharp edges of the mixing chamber, which will reduce the quality of oil treatment.

The technical problem solved by the invention is to increase the yield of target oil products, improve their quality and reduce energy costs for oil processing.

The technical result of the invention is to improve the quality of oil for its subsequent processing by breaking the integrity of molecular chains and breaking bonds between individual parts of molecules.

The technical result of the invention is achieved due to the implementation of the oil treatment method, which consists in the fact that oil is fed into the mixer, in the spiral chamber of which a turbulent vortex motion is created by the oil flow with the formation of a cavitation cavity in the central part of the spiral chamber, where oil is processed by hydrodynamic vortex cavitation, and oil heated to a subcritical temperature is supplied to the mixer, while using the mixer speed controller, the oil supply rate is regulated in the range from 48 to 53 m/s until a stable cavitation cavity is formed.

The invention is illustrated by drawings, where in Fig. 1 and 2 show a mixer with which the proposed method is implemented; in fig. 3 shows section A-A in FIG. 1; in fig. 4 shows a section B-B in Fig. 2; in fig. 5 shows the results of industrial tests of the claimed method using a mixer for West Siberian oil.

The proposed method is intended for processing heavy, medium and light oil and serves to improve the quality of oil for its subsequent processing in order to increase the yield of target oil products (diesel fraction), improve oil quality, reduce energy costs for oil processing, increase the shelf life of oil with the exception of its delamination, reduction of salts in oil.

The proposed method is implemented using a mixer with developed hydrodynamic cavitation, which contains a mixing chamber 1 with an inlet pipe 2 for introducing mixture components. With the chamber 1 mixing is connected to the chamber 3 homogenization of the mixture obtained, having an outlet pipe 4 or nozzle. The mixing chamber 1 is equipped with a regulator 5 for the flow rate of the mixture components introduced into it, made in the form of a rotary blade installed at the inlet to the mixing chamber 1 with the possibility of locking it in a predetermined position. In cross section, the mixing chamber 1 may be in the form of a single helix turn (Fig. 3) or the form of two helical turns of a larger and smaller diameter (Fig. 4). The homogenization chamber 3 is connected to the helical coil of the mixing chamber 1, and in the case of a two-turn helix, to a smaller coil of the mixing chamber 1. On the side wall of the chamber 1, one or more holes 6 can be made for supplying additional components or reagents.

With a two-turn spiral chamber 1, the wall of the smaller coil 7 of the chamber 1 spiral has the form of a spherical layer, while the smaller coil 7 is connected to the homogenization chamber 3. The coils 7 and 8 of the helical chamber 1 evenly narrow along the flow, as a result, the pressure in the two coil chamber 1 decreases due to the high flow rates of the medium, causing flow cavitation. With a two-turn helix, the flow rate controller 5 is made in the form of a double blade, each of which is installed at the inlet of the corresponding turn of the helix.

The outlet 4 can be connected to the homogenization chamber 3 via a nozzle 9 in the form of a spherical layer. In the homogenization chamber 3, the process of reducing the heterogeneity of mixtures by grinding and uniformly redistributing them over the flow volume occurs due to the hydrodynamic vortex type of cavitation. Due to the fact that the nozzle 9 has the shape of a spherical layer, the flow of the mixture obtained in the mixing chamber 1, after passing through the homogenization chamber 3, becomes more uniform and is strictly directed to the outlet pipe 4, excluding the formation of cavitation erosion at the outlet.

The proposed method is as follows.

Oil, having a density, mainly from 820 to 855 kg/m ³ , heated to a subcritical temperature, is fed into the mixer through the inlet pipe 2. The subcritical temperature is the temperature at which the oil does not yet boil, but is close to it (the beginning of boiling until bubbles form). For each type of oil (heavy, medium, light, depending on the density of the oil), the subcritical temperature is different and it is determined empirically.

Through the inlet pipe 2, oil heated to a subcritical temperature is fed into a spiral chamber 1, inside which a turbulent vortex motion is created by the oil flow with the formation of a cavitation cavity in the central part of the spiral chamber 1, in which a pressure below atmospheric pressure is created and maintained, where the oil is processed by hydrodynamic vortex cavitation. The cavitation cavity is created by adjusting the oil supply rate in the mixer chamber 1 using the regulator 5.

In this case, depending on the density of the oil, the speed of oil supply to the helical chamber 1 of the mixer is regulated in the range from 48 to 53 m/s until a stable cavitation cavity is formed.

The regulation of the oil supply rate to the required speed (depending on the type of oil) for the formation of a stable cavitation cavity (cavity) is also carried out experimentally using the speed controller 5. In this case, when turning the rotary blade, an increase or decrease in the rarefaction in the cavitation cavity occurs, which, in turn, leads to a decrease or increase in the size of the droplets of the reagents. If after the final treatment of the oil, which has been pre-treated by the proposed method, the amount of light particles (diesel) at the outlet decreases, then the oil supply rate to the mixer is increased until the decrease in the light particles outlet stops (and vice versa).

The spiral shape of chamber 1 and the oil supply rate, controlled by a rotary blade (regulator 5) in the range from 48 to 53 m/s, contribute to the fact that mixing of components begins in the cavitation cavity under local exposure to a higher temperature and higher pressure than in the original components.

Inside chamber 1, the droplet size is reduced and the mixture flow becomes stationary. At the same time, from the mixing chamber 1, the mixture enters the homogenization chamber 3 in a strictly directed manner, where the mixing process is completed.

After passing through the homogenization chamber 3, the mixture enters the outlet pipe 4 in a strictly directed direction and flows out of it.

Thus, as a result of exposure to oil by processing it by the proposed method using a hydrodynamic vortex field, the oil dispersion system changes. During this process, the diffusion of oil in the area of paraffin is accelerated, which provokes its destruction. To accelerate the dissolution of paraffin, it is necessary to intensify the mixing of oil at the oil-paraffin interface and the action of pressure pulses. Compliance with these conditions allows you to disperse (scatter, spray) paraffin particles. Oil contains long, randomly arranged molecules of paraffin and resins, which form a kind of flexible lattice in which the solution is located. Hydrodynamic cavitation breaks the integrity of the chain, destroying the bonds between the individual parts of the molecules. Due to the decrease in the melting and evaporation temperature of smaller particles of the dispersed phase, the yield of target oil products (diesel fraction) increases, their quality improves, and energy costs for oil processing are reduced.

Hydrodynamic vortex cavitation affects the change in the structural viscosity of heavy, medium and light oils.

It is known that cavitation occurs when the flow reaches the limiting velocity, when the pressure in the flow becomes equal to the pressure of vaporization (saturated vapors). This speed corresponds to the boundary value of the cavitation criterion.

Oil, in addition to carbon, also contains molecules of water, sulfur, paraffin and mechanical impurities. Most of the oil molecules are in a polymerized state.

The fewer molecular bonds in the oil, the easier it is to process further. The use of hydrodynamic cavitation treatment of oil leads to the destruction of these bonds, which in turn leads to a number of positive results (improvement of the characteristics of mixed oil, reduction of corrosion of pipelines, reduction of mercaptan sulfur). As a result of all this, homogeneity of the finished product is achieved.

Molecular bonds are reduced due to the effect of the vacuum cavity in the mixer due to the oil feed rate. The optimal oil feed rate (depending on oil density) is from 48 to 53 m/s. If the speed is higher, then the oil mixture passes by the cavity; if the speed is less, then a vacuum cavity is not formed.

The optimal vortex flow for good oil quality is created at an oil feed rate of 50-53 m/s, with this vortex flow speed mode, a maximum cavitating cavity and a maximum output of light particles are formed. However, for a different type of oil (dense or viscous), the optimal eddy flow is achieved at other speeds in the range from 48 to 50 m/s.

The following are examples of the invention.

Example 1

A mixer with a throughput of 4.5 m ³ /hour was used to process the oil. They took oil with a density of 820 kg/m ³ and heated it to a subcritical temperature. Empirically, it was found that the subcritical temperature of such oil was up to 50°C. Next, the oil heated to this temperature was pumped into the mixer, and the rate of oil supply to the mixer was controlled until a stable cavitation cavity was formed. Empirically, it was found that such an oil supply rate was 48 m/s. As a result, it was found in the laboratory that the amount of light particles (diesel fraction) obtained at the outlet of the mixer increased by 12% compared to the original oil, which was not processed through the mixer in the described way.

Example 2

A mixer with a throughput of 4.5 m ³ /hour was used to process the oil. They took oil with a density of 840 kg/m ³ and heated it to a subcritical temperature. Empirically, it was found that the subcritical temperature of such oil was up to 52°C. Next, the oil heated to this temperature was pumped into the mixer, and the rate of oil supply to the mixer was controlled until a stable cavitation cavity was formed. Empirically, it was found that such an oil supply rate was 50 m/s. As a result, it was found in the laboratory that the amount of light particles (diesel fraction) obtained at the outlet of the mixer increased by 10% compared to the original oil, which was not processed through the mixer in the described way.

Example 3

A mixer with a throughput of 4.5 m ³ /hour was used to process the oil. They took oil with a density of 855 kg/m ³ and heated it to a subcritical temperature. Empirically, it was found that the subcritical temperature of such oil was up to 54°C. Next, the oil heated to this temperature was pumped into the mixer, and the rate of oil supply to the mixer was controlled until a stable cavitation cavity was formed. Empirically, it was found that such an oil supply rate was 53 m/s. As a result, it was found in the laboratory that the amount of light particles (diesel fraction) obtained at the outlet of the mixer increased by 8% compared to the original oil, which was not processed through the mixer in the described way.

In addition, in all cases of oil treatment by the proposed method, it was found that the amount of salts is reduced compared to the oil that has not been processed by the proposed method. It was also noted that the oil treated by the proposed method did not delaminate for a very long time (more than 6 months), which allows storing the treated oil for a significant time for its subsequent processing.

Table 1 below shows the values of the test results for West Siberian oil. These values are shown in the diagram in FIG. 5. At the same time, tests were carried out both without using the proposed method (sample without a mixer), and with the proposed method using a mixer (samples 1 to 7).

Table 1 Oil sample number Oil property indicators Pressure drop in the mixer, kg / cm ² (depending on the oil feed rate) Boiling point (NK), °C Boils up to 180°С, % Boils up to 360°С, % Yield of light particles, % mass 1 52 25 63 66 1.0 2 58 24 62 64 4.0 3 52 25 67 71 7.5 4 62 23 59 62 10.0 5 54 24 65 68 4.0 6 50 23 67 70 7.5 7 62 22 59 62 10.0 8 50 22 59 62 Without mixer

In line 8 of the sample, the oil indicators for the sample without using a mixer at LC 50 ° C are indicated;

For 1 sample, oil indicators are indicated using a mixer and the proposed method at NC 52°C and a pressure drop in the mixer of 1.0 kg/cm ² ;

For 2 samples, the oil indicators are indicated using a mixer and the proposed method at NC 58°C and a pressure drop in the mixer of 4.0 kg/cm ² ;

For the 3rd sample, oil indicators are indicated using a mixer and the proposed method at NC 52°C and a pressure drop in the mixer of 7.5 kg/cm ² ;

For 4 samples, the oil indicators are indicated using a mixer and the proposed method at NC 62°C and a pressure drop in the mixer of 10.0 kg/cm ² ;

For the 5th sample, the indicators of oil are indicated using a mixer and the proposed method at NC 54°C and a pressure drop in the mixer of 4.0 kg/cm ² ;

For 6 samples, oil indicators are indicated using a mixer and the proposed method at NC 50°C and a pressure drop in the mixer of 7.5 kg/cm ² ;

For sample 7, oil indicators are indicated using a mixer and the proposed method at NC 62°C and a pressure drop in the mixer of 10.0 kg/cm ² .

Claims (1)

Oil treatment method, which consists in the fact that oil is fed into the mixer, in the spiral chamber of which a turbulent vortex motion is created with the oil flow with the formation of a cavitation cavity in the central part of the spiral chamber, where the oil is processed by hydrodynamic vortex cavitation, characterized in that the oil is fed into a mixer of oil heated to a subcritical temperature, at which the oil does not yet boil to the formation of bubbles, while using the speed controller of the mixer, made in the form of a rotary blade installed at the inlet to the spiral chamber with the possibility of fixing it in a predetermined position, regulate the oil supply rate in the range from 48 to 53 m/s until the formation of a stable cavitation cavity.

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