RU2433161C1 - Method for separating mixed fluid containing oil and/or mineral oil and related equipment for implementation thereof - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: invention concerns a method for separating a mixed fluid containing oil and/or mineral oil that involves induction of a pre-selected gas including carbon dioxide or nitrogen with the mixed fluid to be separated with the use of a supersonic jet pump with the gas and the fluid to be separated circulating in appropriate closed loops, separation of a steam-and-gas phase, steam condensation, collection of a condensed component; what is induced is the mixed fluid at temperature 35-200°C under pressure to provide a fluid outlet flux of 20-28 m/s, and outlet atmospheric pressure is maintained. Also, the invention concerns equipment mounted for implementing the method.

EFFECT: high-efficiency continuous separation of oil or mineral oil.

5 cl, 3 ex, 3 dwg

Description

The invention relates to methods for the separation of oil mixtures, incorporating light fractions with different boiling points, and can find application in the oil, oil refining industry and other industries.

To date, all traditional methods of crude oil refining include three stages in general:

- stage of oil preparation (desulfurization, removal of hydrophilic impurities, water and salts);

- the stage of primary atmospheric vacuum direct distillation with the formation of light fractions and fuel oil;

- stage of catalytic cracking of fuel oil with the output of an additional quantity of light fractions and paraffin.

Recently, various methods of oil pretreatment have been developed, aimed at partially changing the structure of hydrocarbon bonds in order to increase the yield of light fractions at the very first stage of direct oil distillation.

A known method of processing oil and oil products by exposing them to ionizing излучения-radiation or a fast neutron flux, after which the product is subjected to catalytic cracking, or hydrotreating, or electrodesalting (RU 2100404, 12/27/1997).

The disadvantage of this method of processing petroleum products is the resulting radiation hazard and the associated great complexity of the installation and its maintenance.

There is a method according to which, before supplying stripped oil for distillation into an atmospheric column or fuel oil into a vacuum column, the oil stream is subjected to complex hydromechanical and acoustic processing in a rotary pulsating acoustic apparatus at a rotor speed of 1000-12500 rpm, acting with an acoustic field of intensity 10 ² -10 ⁵ W / cm ² in the frequency range of disk-fan oscillations of the rotor and stator of 0.01-63.0 kHz. As a result of this pre-treatment, the yield of petroleum distillates increases compared to traditional methods (RU 2158288, 10.27.2000).

The disadvantages of the above method of complex hydromechanical and acoustic processing in a rotary pulsating acoustic apparatus are the high energy and material consumption, as well as the fact that it is not possible to directly obtain oil distillates with it.

A known installation to facilitate the rectification of petroleum raw materials without preliminary preparation using a liquid-gas jet apparatus, which is used to create a vacuum in distillation columns. It is installed at the outlet of the distillation column in front of the separator. As a liquid working medium, a liquid working medium with a saturated vapor pressure not lower than the pressure in a vacuum distillation column is fed into the nozzle of a liquid-gas jet apparatus, while maintaining a pressure in the separator of 1.1 to 160 pressures of the vapor-gas phase at its inlet to the distillation the column. After mixing the vapor-gas phase and the liquid working medium in a jet apparatus, before the supply of this mixture to the separator, the process of condensation of the easily condensable components of the combined-gas phase is organized in the liquid working medium (RU 2113634, 06.20.1998).

The disadvantage of this device is its complexity, as well as the fact that it is only an auxiliary tool, and the process of separation of light fractions is carried out in a traditional distillation column.

The closest in technical essence is the method of separation of a liquid mixture containing oil and / or oil products, including ejecting a pre-selected gas with a separated liquid mixture using a supersonic ejector during gas circulation and the separated mixture through appropriate closed loops, gas-vapor phase separation, vapor condensation, condensed condensate collection components (RU 2165281, 04.20.2001).

According to this method, the gas is ejected with the initial mixture at a speed of at least 30 m / s, with a temperature higher than the temperature at which the saturation pressure of the removed boiling components is equal to the minimum absolute pressure created by the initial ejected liquid without air leakage, and this mixture is mixed with gas in a supersonic liquid-gas ejector, while ensuring a mass ratio of the total flow rate of the ejected air and the released steam of the boiling component to the flow rate of the original Liquids in the range of 0.00001 to 0,005 to form a supersonic two phase equilibrium mixture, while maintaining the constant pressure in the gas loop system and a constant vacuum in the receiving chamber of the ejector. In principle, it can be used to separate any liquid mixtures consisting of components with different boiling points, for example, to separate water-alcohol mixtures or to separate gasoline from water.

The disadvantage of this method is the impossibility of a continuous separation process and the complexity of the processes of maintaining a constant pressure in the gas circuit of the system and constant vacuum in the receiving chamber of the ejector.

There is also known a device for separating liquid media, which contains an electric pump connected in series by pipelines, a nozzle block of a liquid-gas ejector, a sealed tank, the upper part of which is connected by a recirculation line to a device for separating a droplet entrainment of a liquid mixture from a vapor-gas mixture, a cooled condenser, condensable collectors liquids and instrumentation (RU 2165281, 04.20.2001).

In the known installation, it is possible to carry out the separation of light fractions of petroleum products, for example gasoline, however, for the fractional separation of oil, the installation is ineffective due to the following factors:

- the foam sludge tank or antifoam used as a device for separating the liquid phase from the gas-vapor mixture is ineffective and inefficient;

- the expansion compensator installed on the collector-drive of the condensed liquid phase does not allow for a stable operation of the ejector at atmospheric pressure.

- the installation does not allow the process of separation of oil mixtures in continuous mode.

The present invention is the creation of a high-performance simple and reliable method and installation for its implementation, suitable for the separation of any type of oil mixtures to obtain petroleum distillates, including highly viscous "heavy" oil.

The problem is solved by the described method of separating a liquid mixture containing oil and / or oil products, including ejecting a pre-selected gas with a separated liquid mixture using a supersonic ejector during gas circulation and the separated mixture through appropriate closed loops, separating the gas-vapor phase, vapor condensation, collecting the condensed component, according to which the mixture is fed to the ejection at a temperature of 35-200 ° C under pressure, providing a mixture speed at the inlet of the ejector equal to 20-28 / S at the outlet of the ejector is maintained at atmospheric pressure.

As a pre-selected gas, carbon dioxide or nitrogen is used.

After separation of the mixture, the gasoline fraction is subjected to sedimentation.

The problem is also solved by the described installation for implementing the inventive method, comprising at least one module, comprising a tank connected for piping for a shared liquid oil mixture, an electric pump, a heat exchanger, a supersonic liquid-gas ejector unit, a device for separating the vapor-gas phase from the liquid phase, a condenser capacity for collecting the condensed phase, while the connecting pipelines are installed with the formation of two closed loops for the liquid and gas-vapor phases, respectively but, the ejector outlet confuser is directly connected to the device for separating the gas-vapor phase from the liquid, made in the form of a cyclone mounted vertically, the upper part of which is connected to the gas-vapor phase condenser, and the lower part to the tank for the mixture to be separated, the tank being equipped with a gas expansion expander phase, located in its upper part, and nozzles for supplying and outputting oil products.

Preferably, the installation comprises a unit of several supersonic ejectors connected in parallel.

Preferably, the installation contains 2-4 series-connected modules, in the first of which gasoline is condensed in the direction of the liquid mixture, in the second-third is light and heavy gas oil, and in the fourth is diesel fuel, and the input mixture of the initial mixture of each subsequent module is connected to the outlet pipe heavy fraction of the previous module. The technical result of the claimed process of separation of the oil mixture is provided by the above set of features, since the gas circulation in a closed circuit occurs continuously due to gas ejection of the most separated mixture circulating in a closed circuit using an electric pump. The efficiency of separation of a low-boiling component (first gasoline, then gas oil and diesel) is ensured by the effective crushing of the separated liquid in the shock waves formed during braking of a two-phase gas-liquid mixture at the exit of a supersonic ejector. Due to this, at relatively low temperatures (35-200 ° C), it is possible to ensure almost complete primary distillation of oil, which in a conventional distillation column takes place at 400-450 ° C. Thus, a large saving of thermal energy is achieved. Subsequent cooling of the vapor-gas mixture formed by passing through the ejector in the condenser leads to the separation of low-boiling oil and water fractions. The temperature of the gas suitable for the ejector is almost equal to the temperature in the condenser, and when mixed with the mixture to be separated in the mixing chamber of the ejector, the temperature of the gas rises to the temperature of the mixture being treated and the gas becomes “dry-dry” with respect to the removed component, which effectively absorbs itself pairs of separable components and transports them.

The accumulated condensed phases of light oil products are collected in separate containers, the gas is again fed to the ejection, ensuring the continuity of the process, while maintaining constant atmospheric pressure in a sealed container with a shared mixture.

The speed interval of 20-28 m / s is due to the following. The minimum value of the speed of sound in an equilibrium water-air mixture can be about 20 m / s at a mixture pressure of 1 at. Therefore, in order to realize a supersonic flow and subsequent shock-wave treatment of the two-phase mixture formed in the ejector, it is sufficient to supply the treated liquid to the ejector mixing chamber at a speed slightly higher than the speed of sound, i.e. 20 m / s. With a significant excess of this indicator, energy costs will increase sharply (for example, a 2-fold increase in the liquid velocity in the ejector automatically leads to the need to increase the supply pressure by 4 times). Therefore, for low-viscosity mixtures, it is sufficient to provide a feed rate in the range of 20-24 m / s. When separating highly viscous petroleum products to ensure normal operation, it was experimentally established that a necessary and sufficient sign is to ensure speed in the range of 24-28 m / s.

A diagram of a typical installation module with an indication of its main elements is shown in figure 1.

It was established experimentally that to obtain a gasoline fraction from the oil mixture in the module, it is sufficient to maintain the temperature up to 105 ° C, while the process itself begins when the feedstock in the installation is heated to 35 ° C. The temperature of 95-105 ° C is the working interval of the first module, 120-150 ° C - of the second, and 180-200 ° C - of the third. Accordingly, during the continuous process of distillation of crude oil in the first module, gas will be produced, in the second - gas oil, and in the third - diesel fuel. In the case of a similar process in the "Angler" flask, full acceleration is carried out when the oil is heated above 400 ° C.

An installation consisting of three series-installed modules, each of which maintains an optimal temperature range for the continuous production of a gasoline fraction (t = 95-105 ° C), gas oil (t = 120-150 ° C) from the initial product (oil mixture) diesel (t = 180-200 ° C), is shown in figure 2. At the exit from each module, the corresponding products are obtained (gasoline, gas oil, diesel fuel). And as the bottom residue in the last, third module, a fuel oil fraction is formed.

The illustration of obtaining light oil fractions using ejector distillation, in contrast to conventional atmospheric distillation in an Engler flask, is shown in FIG. 3.

The principle of operation of the installation is illustrated by the following examples.

Example 1. Spent obtaining light fractions of oil by distillation of the sample with a total content of light fractions of 49.9%. The content of light fractions is determined by preliminarily distilling the initial sample in the Engler flask, heating it in the range of 35-400 ° C. An oil mixture with a temperature of 20 ° C and a flow rate of 3.33 g / s (12 l / h) is fed to the unit for processing. The distillation according to example 1 is carried out on the installation depicted in figure 1, which provides for receiving in one hour 6 l of distillates as follows.

The insulated container 1 is filled with the original oil, then all the cavities of the installation are blown (filled) with a pre-selected inert gas. The hot heat carrier is supplied to the nozzle 18 to a heat exchanger for heating the raw material 3, from which the cooled coolant is removed through the nozzle 19. Both water and antifreeze-like liquids can be used as the heat carrier. Turn on electric pump 2 and, when heated to 35 ° C, circulate the separated liquid in a closed circuit: tank - 1, pump - 2, heat exchanger - 3, pipeline for supplying liquid to ejectors - 4, nozzle blocks of ejectors - 5-1, mixing chamber for ejectors, equipped with confusers at the exit - 5-3, centrifugal separator - 6 and again the capacity - 1. Raise the temperature of the oil mixture to 35 ° C and carry out the separation process. The electric pump 2 provides the absolute pressure of the liquid in front of the nozzle blocks of the ejectors, sufficient to realize the flow of gas-liquid mixture in the ejector with a speed in the range of 20-28 m / s. Gas (nitrogen) circulates in a different circuit, consisting of successively installed: receiving chambers of ejectors - 5-2, block of ejectors - 5, in which it is saturated with vapors of a low boiling component (gasoline), centrifugal separator - 6, in which gas is separated from droplets, a heat exchanger - 8, in which the mixture entering the original tank - 1 is heated due to the latent heat of vaporization of the condensate, condenser - 9, into which cold water is supplied through the nozzle 11 and removed through the nozzle 12, the condensate collection tank - 10 and the pipeline - 17, from to torogo gas again flows into the tank 1. Surplus gas during thermal expansion can flow from the separator 6 into the tank 1 and from compensator 7, whereby in tank 1 is constantly maintained at atmospheric pressure. Capacity 1 is equipped with a regulator of the outlet of the finished product 16.

When the oil mixture is heated in the module to 105 ° C, gasoline is completely boiled away, when it is further heated to 150 ° C, gas oil is boiled away, and finally, when heated to 200 ° C, the diesel fraction is completely boiled away. In this example, a total yield of light fractions of 56.7% was obtained, which is 7.7% higher than with ordinary atmospheric distillation.

Example 2

The oil sample is distilled according to Example 1, except that the three-module plant shown in FIG. 2 is used for distillation, each module of which is equipped with an ejector with a capacity of 2.5 m ³ / h. The process is carried out, maintaining in each of the modules a temperature mode pre-configured to receive a certain fraction:

in the first - to obtain a gasoline fraction (at t = 95-105 ° C);

in the second - to obtain a gas oil fraction (at t = 120-150 ° C);

in the third - to obtain a diesel fraction (at t = 180-200 ° C).

For processing served in the first module, as in example 1, the original oil mixture with a temperature of 20 ° C and a flow rate of 3.33 g / s (12 l / h). Heating the oil mixture to the temperature required for each module is provided by heat exchanger 3, and heat exchanger 8 serves to recover heat from the condensing vapors of the distillates produced in each module to heat the raw materials entering this module. The oil mixture is fed through the fitting 13 into the heat exchanger 8, where it is heated by condensing vapors of the gasoline fraction. After that, the mixture is sent through pipeline 14 through an automatic feeder of raw materials with a level gauge 15 to tank 1. Pump 2 provides a feed pressure of the processed raw materials to the nozzle block of the ejector equal to 5 ati, while the flow rate of the gas-vapor mixture in the ejector is 28 m / s. After the gasoline fraction is completely isolated, the “still” residue from the first module is fed to the second, where a similar distillation process is carried out at a temperature of 130-150 ° C. After separation of the gas oil fraction, the "bottom" residue from the second module is fed to the third, where a similar process is carried out at 180-200 ° C. Moreover, in each of the modules in the heat exchanger 8, the latent heat of vaporization of light fractions (gasoline, gas oil and diesel fuel) is transferred to the incoming raw materials. In this example, 58% of the light fractions are obtained, which is 8.1% more than with standard distillation in the cube.

Example 3

The process is carried out as in example 2, except that the initial oil mixture contains 46% of light fractions and an additional 3% of water, and the process of distillation is carried out on a plant containing 4 series-connected modules that are configured in the following temperature regime:

in the first - to obtain a gasoline fraction (at t = 95-105 ° C);

in the second - to obtain a "light" gas oil fraction (at t = 120-130 ° C);

in the third - to obtain a “heavy” gas oil fraction (at t = 140-150 ° C);

in the fourth - to obtain a diesel fraction (at t = 180-200 ° C).

If water is present in the initial oil mixture in the first module at 70-90 ° C, in addition to gasoline vapors, water vapors will be released, as a result of which all water will fall into the gasoline fraction. Due to the difference in densities, it is easily separated from gasoline by settling and, after the end of the process, it is drained from the bottom of the condensate tank 10. In this example, 59% of light fractions are obtained, mainly due to an increase in the diesel and gas oil fractions of oil, which is 9.1% more than in standard overclocking in a cube.

A distinctive feature of this method from all traditional rectification methods is that, in principle, it does not need preliminary separation of water and salts dissolved in it from crude oil. Due to the heating process itself, simultaneously with the ejector circulation of oil raw materials, the possibility of a sharp boiling of water vapor is excluded, therefore, the safety of the process of distillation of oil raw materials with any water content in it is ensured. On the other hand, all salts will remain in the bottom residue (fuel oil fraction) and will not get into light oil products.

In addition, as can be seen from the presented examples, in the process of ejector distillation, a slight increase in the yield of light fractions occurs, which may be associated with chemical reactions that occur in this process.

And finally, unlike standard column rectification, the installation itself is significantly smaller in size, ease of execution and reliability.

Claims (5)

1. The method of separation of a liquid mixture containing oil and / or oil products, comprising ejecting a pre-selected carbon dioxide or nitrogen gas with a separated liquid mixture using a supersonic ejector during gas circulation and the separated mixture in appropriate closed loops, gas-vapor phase separation, vapor condensation, collection condensed component, characterized in that the ejection is fed with a liquid mixture at a temperature of 35-200 ° C under pressure, providing a speed of the mixture at the inlet to the ejector of 20-28 m / s, while and the outlet of the ejector is maintained at atmospheric pressure. 2. The method according to claim 1, characterized in that after separation of the mixture, the gasoline fraction is subjected to sedimentation. 3. Installation for implementing the method described in claim 1, containing at least one module containing pipelined tank for shared liquid mixture, an electric pump, a heat exchanger, a block of supersonic liquid-gas ejector, a device for separating the vapor-gas phase from the liquid phase, a condenser, containers for collecting the condensed phase, while the connecting pipelines are installed with the formation of two closed loops for the liquid and gas phases, respectively, the ejector output confuser directly connected to a device for separating the vapor-gas phase from the liquid, made in the form of a cyclone mounted vertically, the upper part of which is connected to the condenser of the gas-vapor phase, and the lower part is connected to the tank for the mixture to be separated, and the said tank is equipped with a gas phase expander-compensator located in the upper parts of the tank, and nozzles for supplying and outputting oil and / or oil products. 4. Installation according to claim 3, characterized in that each module contains a block of several supersonic ejectors connected in parallel. 5. Installation according to claim 3, characterized in that it contains 2-4 modules connected in series, in the first of which gasoline is condensed in the direction of the liquid mixture, in the second and third light and heavy gas oil, and in the fourth diesel fuel, moreover the input pipe of the initial mixture of each subsequent module is connected to the output pipe of the heavy fraction of the previous module.

Images