CN114425179A

CN114425179A - Phase balance measuring and separating device and application method thereof

Info

Publication number: CN114425179A
Application number: CN202010909723.9A
Authority: CN
Inventors: 廖志新; 罗涛; 王翠红; 佘玉成; 王红
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2020-09-02
Filing date: 2020-09-02
Publication date: 2022-05-03
Anticipated expiration: 2040-09-02
Also published as: CN114425179B

Abstract

A phase balance measuring and separating device and an application method thereof are disclosed, the device comprises a feeding and cleaning system, a balance main kettle, a balance auxiliary kettle and a sampling system which are communicated in sequence; the balance main kettle consists of a balance space at the upper part and a volume adjusting structure at the bottom part, wherein the balance space is provided with a material inlet, a window is arranged on the wall of the balance space, the top part of the balance main kettle is provided with an outlet, and the outlet of the balance main kettle is respectively communicated with the balance auxiliary kettle and the inlet of the sampling system; the balance auxiliary kettle is composed of a balance space at the upper part and a volume adjusting structure at the bottom part, the balance space is provided with an inlet and an outlet, and the outlet of the balance auxiliary kettle is communicated with the inlet of the sampling system. The phase balance measuring and separating device provided by the invention adopts a window to observe the movement condition of the interface, the manufacturing cost of the device is reduced, and the phase balance of the system is not influenced in the separation process of the light phase and the heavy phase after extraction.

Description

Phase balance measuring and separating device and application method thereof

Technical Field

The invention belongs to the field of chemical engineering, and relates to a phase balance measuring and separating device with high-temperature and high-pressure visual adjustable volume and a using method thereof.

Background

The solvent deasphalting technology is one of the important technologies for the heavy oil lightening, and the combined process is an attractive development direction for the maximum processing and utilization of the heavy oil. Solvent deasphalting is a physical process of liquid-liquid extraction, which separates the components of residual oil according to the different solubilities of the solvent. Although there is a long history of solvent deasphalting process industrialization, the composition of the residual oil is very complex, and the properties of the residual oil from different sources are very different, so that basic research works such as residual oil property analysis and phase balance must be carried out in order to accurately predict the yield and product properties of deasphalted oil and provide reliable basic design data. Many solvent deasphalting plants are currently in operation and due to the lack of research on the application base, there is a certain difficulty in optimizing their operation, which necessitates the optimization of the process by establishing a mathematical model of the deasphalting process. In order to establish a model of the solvent deasphalting process, studies on physical property data and phase balance of the deasphalting process must be carried out. In addition, the fundamental data of phase volume and phase density, which are important for the design of solvent deasphalting towers, are lacking.

The current phase equilibrium research relates to various aspects such as distillation, extraction, dissolution, recrystallization, purification, metallographic analysis and the like, and has a far-reaching significance for scientific research and production of chemistry and chemical engineering. The high-pressure visual phase equilibrium still is the main instrument for researching thermodynamic phase equilibrium and observing high-pressure reaction. One important method for observing high-pressure phase equilibrium is a variable-volume static method, the prepared raw materials are placed in a balance tank, the temperature and the pressure are adjusted until two phases appear, and then the two phases of the equilibrium are sampled. The pressure can be kept stable by changing the volume of the system in the sampling process, so that the obtained phase equilibrium data is more accurate than a constant volume static method, and more separated samples can be obtained for further property analysis. In order to obtain basic data of phase equilibrium research, experimental equipment capable of measuring phase equilibrium data under the condition of simultaneous existence of high temperature and high pressure is indispensable, however, most of phase equilibrium measuring devices of the volume-variable static method at home and abroad can only work at the temperature lower than 200 ℃.

CN101021519A discloses a phase balance measuring device with high pressure, visual and adjustable volume, which adopts a cylinder structure with a window, wherein an adjusting screw rod is arranged on a central shaft of an adjusting bracket on the upper part of a cylinder and is connected with a plunger piston in the cylinder to drive the plunger piston to move up and down in the cylinder; the two ends of the bottom of the cylinder are respectively externally connected with CO through a liquid outlet joint and a liquid inlet joint₂A fluid and feeding system, and a magnetic stirring controller arranged at the lower part of the device. The measuring temperature is up to 200 ℃, and the pressure is up to 40 MPa. CN101819170A discloses a non-integral variable volume high pressure phase balance measuring device, which makes full use of a fixed volume phase balance pool and adjusts the pressure of the whole system through an externally connected adjustable volume pressure reduction container. CN205146108U discloses a rapid gas-liquid phase balancing device under high pressure, which belongs to phase balancing by a circulation method and consists of a high-pressure gas-liquid balancing system and a high-pressure sampling system; the high-pressure gas-liquid phase balance system consists of a high-pressure balance kettle and a gas-liquid countercurrent double-circulation system. The pressure is generally not readily stabilized during operation of the recycle process. The use of the recycle process in residuum systems has not been reported.

The prior art has the following defects: (1) the detection time is long. The mode that the magnetic ring drives the magnetic ring to move up and down is adopted, and the stirring time of more than 4 hours is usually needed for a residual oil high-viscosity system. (2) The fixed-volume visible phase balance kettle is high in manufacturing cost, and the sample amount obtained in one experiment is too small. (3) The applicable temperature range is not wide, and most of phase equilibrium measuring devices of the variable volume static method at home and abroad can only work at the temperature lower than 200 ℃. The present invention is directed to solving the above problems.

Disclosure of Invention

One of the technical problems to be solved by the invention is to provide a visual adjustable volume phase balance measuring and separating device suitable for high temperature and high pressure conditions, and overcome the defects of long time required for achieving phase balance, high manufacturing cost and relatively low applicable temperature in the prior art.

The second technical problem to be solved by the invention is to provide a hydrocarbon mixture phase equilibrium separation and determination method suitable for high temperature and high pressure conditions.

In order to achieve the purpose, the invention adopts the following technical scheme:

a phase balance measuring and separating device comprises a feeding and cleaning system, a balance main kettle 8, a balance auxiliary kettle 21 and a sampling system which are communicated in sequence;

the balance main kettle consists of a balance space at the upper part and a volume adjusting structure at the bottom part, wherein the balance space is provided with a material inlet, a window is arranged on the wall of the balance space, the top part of the balance main kettle is provided with an outlet, and the outlet of the balance main kettle is respectively communicated with the balance auxiliary kettle and the inlet of the sampling system;

the balance auxiliary kettle is composed of a balance space at the upper part and a volume adjusting structure at the bottom part, the balance space is provided with an inlet and an outlet, and the outlet of the balance auxiliary kettle is communicated with the inlet of the sampling system.

The invention provides a hydrocarbon mixture phase equilibrium separation and determination method, which adopts the phase equilibrium determination and separation device and comprises the following steps:

(1) introducing a hydrocarbon mixture to be separated into a balance main kettle, and pressing a solvent into the balance main kettle by using a feeding and cleaning system;

(2) heating the balance main kettle to an operation temperature, adjusting the volume of a balance space to be unchanged, and standing the mixture of the solvent and the hydrocarbon after extraction and separation to be divided into an upper layer light phase and a lower layer heavy phase;

(3) adjusting the balance space volume of the balance auxiliary kettle to be minimum, communicating the balance main kettle and the balance auxiliary kettle, increasing the balance space volume of the balance auxiliary kettle, keeping the pressure of the balance main kettle, transferring the light phase from the balance main kettle to the balance auxiliary kettle, and stopping transferring the sample when the phase interface moves to the top of the window through the window observation;

(4) adjusting the balance space volume of the balance auxiliary kettle to be maximum, and heating to completely gasify the solvent in the light phase; opening an outlet of the balance auxiliary kettle, reducing the volume of a balance space, and enabling gas and light phase to enter a sampling system;

(5) communicating the outlet of the balance main kettle with a sampling system, reducing the volume of a balance space of the balance main kettle, and enabling gas and a heavy phase to enter the sampling system;

(6) the feeding and cleaning system respectively introduces the cleaning solution into the balance main kettle and the balance auxiliary kettle for cleaning and discharging.

Compared with the prior art, the phase balance measuring and separating device and the using method thereof provided by the invention have the beneficial effects that:

the phase balance measuring and separating device provided by the invention has the advantages that the top of the balance main kettle adopts a window with relatively small inner diameter to observe the movement condition of the interface, and the two-phase separation effect is good. The device cost is reduced, provides bigger balanced main cauldron reaction space simultaneously and obtains more experimental separation sample for further nature analysis. The arrangement of the variable volume balance main kettle and the invisible variable volume balance auxiliary kettle with the windows at the top can realize mutual sample transfer between the main kettle and the auxiliary kettle and ensure that the phase balance of a system is not influenced in the separation process of light phases and heavy phases.

Drawings

FIG. 1 is a schematic view of a phase equilibrium measuring and separating apparatus according to an embodiment.

FIG. 2 is a top view of the main equilibrium reactor.

Wherein:

1-high precision plunger pump; 2-a liquid washing tank; 3-a solvent tank; 4-a raw material inlet;

5. 6, 19, 20-quick joint; 7-a window; 8-balancing the main kettle; 9-stirring blades;

10. 22-a piston; 11-semi-open type heat preservation sleeve; 12-magnetic drive agitator;

13-a piston holder; 14. 24-a screw; 15. 16, 23-nut;

17. 25-kettle body rotating motor; 18-kettle body support; 21-balance auxiliary kettle; 26-support;

27-a buffer tank; 28-a gas flow meter; 29-gas collection means.

Detailed Description

The present application will now be described in further detail with reference to specific embodiments thereof, it being understood that the specific embodiments described herein are merely illustrative and explanatory of the present application and are not restrictive thereof in any way.

In the present application, the terms "upper", "lower", "top" and "bottom" are used based on the relative positional relationship of the containers. For example, the "bottom" refers to the position of 0-10% of the container from the bottom up, and the "top" refers to the position of 90-100% of the container from the bottom up.

Unless otherwise defined, terms used herein have the same meaning as commonly understood by one of ordinary skill in the art, and if a term is defined herein and its definition is different from that commonly understood in the art, the definition herein controls.

In the present application, anything or things that are not mentioned are directly applicable to those known in the art without any change except what is explicitly stated. Moreover, any embodiment described herein may be freely combined with one or more other embodiments described herein, and the technical solutions or ideas thus formed are considered part of the original disclosure or original description of the present invention, and should not be considered as new matters not disclosed or contemplated herein, unless a person skilled in the art would consider such combination to be clearly unreasonable.

Optionally, the feeding and cleaning system comprises a washing liquid tank 2 and a solvent tank 3 which are connected in parallel, an outlet of the solvent tank is communicated with an inlet of the balance main kettle, an outlet of an opening of the washing liquid tank is communicated with a material inlet of the balance main kettle and an inlet of the balance auxiliary kettle, the bottoms of the washing liquid tank and the solvent tank are communicated with the high-precision plunger pump 1, and feeding of the solvent and the washing liquid is controlled through pressure transmission liquid.

Optionally, the sampling system comprises a buffer tank 27, a gas flow meter 28 and a gas collection device 29 which are communicated in sequence.

Optionally, the inlet of the balance main kettle is also communicated with a raw material inlet 4.

Optionally, the window is a sapphire cylinder with an inner diameter of 5-20mm and a height of 20-50 mm; the window is hermetically connected with the top of the balance space of the balance main kettle; preferably, the window is pressed at the top of the balance space by a pressing mechanism, and high-temperature and high-pressure resistant gaskets are arranged above and below the window.

Optionally, the inner diameter of the balance space in the balance main kettle is 30-150mm, and the height is 50-200 mm. The balance space is cylindrical or is in a truncated cone shape with the inner diameter reduced from bottom to top; and a sapphire cylindrical window with a reduced pipe diameter is arranged at the top of the balance space.

Optionally, the volume adjusting structure is a piston tightly combined with the inner wall of the cylinder. And a sealing ring is arranged between the piston and the inner wall of the cylinder body, and the sealing ring is matched with a polyimide check ring by a perfluoroether O-shaped ring and is filled with heat-conducting silicone grease. The bottom of the balance main kettle realizes the variable volume of a balance space through a piston. The balance auxiliary kettle realizes the variable volume of a balance space through a bottom piston, and a sealing ring is arranged between the piston and a balance auxiliary kettle cylinder; the sealing ring with the perfluoro ether O-shaped ring and the polyimide check ring matched can achieve a good sealing effect.

Optionally, a magnetic transmission stirrer 12 is arranged at the lower part of the piston 10 at the bottom of the balance main kettle; the stirring paddle 9 of the magnetic transmission stirring machine is arranged on the upper surface of the piston, a support 26 is arranged on the periphery of the stirring paddle and fixed on the upper surface of the piston, and the height of the support is higher than that of the stirring paddle. Preferably, the support is 3-10mm above the agitated slurry. The piston is provided with a support to prevent the stirring blade from being crushed when the piston moves to the top of the balance main kettle.

Optionally, a water cooling device is arranged outside the magnetic transmission stirring machine. And the magnetic steel is ensured not to be demagnetized even if the magnetic steel runs in a high-temperature medium environment for a long time.

Optionally, the stirring blade is a cross propeller type, and a plurality of obliquely upward elliptical or circular blades are arranged on the cross. When the cross propeller type stirring paddle is adopted to rotate, upward thrust is formed to achieve a better stirring effect.

Optionally, the bottom of the piston at the bottom of the main balance kettle is connected with an adjusting screw rod, the adjusting screw rod of the main balance kettle is composed of a piston support 13, a fixed screw rod 14 and a nut 15, the piston support is movably fixed on the fixed screw rod through the nut, one end of the fixed screw rod is connected with a rotating shaft of the motor, and a gap is reserved between the other end of the fixed screw rod and the bottom surface of the piston. When the piston is positioned at the lowest end of the balance space of the balance main kettle, the fixed screw can be contacted with the bottom of the piston; when the piston is positioned at the topmost end of the balance space of the balance main kettle, the distance between the top end of the fixed screw rod and the magnetic transmission stirrer at the bottom of the piston is not less than the height of the balance space. The screw rod is controlled by the motor to rotate, and the piston at the bottom of the balance main kettle is controlled to move up and down. The screw is spaced from the piston to allow room for the placement of the magnetic drive agitator. And a piston at the bottom of the balance auxiliary kettle adopts a conventional screw rod adjusting mode.

Optionally, the bottom of the piston at the bottom of the balance auxiliary kettle is connected with an adjusting screw rod, the adjusting screw rod of the balance auxiliary kettle consists of a kettle body support, a screw rod 24 and a nut 23, the screw rod is in contact with the bottom of the piston, the screw rod is movably fixed on the kettle body support through the nut, and the other end of the screw rod is connected with a rotating shaft of the motor.

Optionally, the balance main kettle and the balance auxiliary kettle are made of stainless steel, the highest withstand temperature is 320 ℃, and the highest withstand pressure is 50 MPa. The materials of the balance main kettle and the balance auxiliary kettle are preferably 316L stainless steel materials.

Optionally, the bottom of the balance main kettle and the bottom of the balance auxiliary kettle are provided with rotating structures, each rotating structure comprises a support 18, a rotating screw and a kettle body support, the supports movably support the rotating screw, one end of the rotating screw is fixedly connected with the kettle body support, and the other end of the rotating screw is connected with a rotating shaft of a kettle body rotating motor. The balance main kettle and the balance auxiliary kettle respectively realize the rotating function of the reaction kettle body through the motor.

Optionally, a temperature sensor and a pressure sensor are arranged in a balance space of the balance main kettle and the balance auxiliary kettle;

optionally, the balance main kettle and the balance auxiliary kettle are externally provided with heat insulation sleeves 11. More preferably, a semi-open type heat preservation sleeve is adopted for temperature control.

In the phase balance measuring and separating device provided by the invention, the inlets and the outlets of the balance main kettle and the balance auxiliary kettle are respectively provided with a quick connector so as to realize the quick connection of pipelines.

The invention provides a method for separating and determining the phase equilibrium of a hydrocarbon mixture, which comprises the following steps:

In the method provided by the invention, after the sampling system finishes sampling the gas and the light phase in the balance auxiliary kettle, the sampling system is disconnected from the balance auxiliary kettle, a new pipeline is preferably selected to connect the balance main kettle with the sampling system, the balance space volume of the balance main kettle is reduced, the gas and the heavy phase enter the sampling system, the mass of the heavy phase separation material is collected and measured through the buffer tank, and the gas volume is measured through the gas flowmeter.

In the phase equilibrium determination and separation device and the using method thereof provided by the invention, the hydrocarbon mixture is residual oil, and the solvent is C3-C6 alkane or a mixture thereof; the washing liquid is petroleum ether or toluene. The phase separation operation temperature is 50-250 deg.C, and the pressure is 3-20 MPa.

The phase balance measuring and separating device and the application method thereof provided by the invention have the following beneficial effects in a preferred embodiment:

the piston at the bottom of the balance main kettle of the phase balance measuring and separating device is coupled with the magnetic transmission stirrer; the magnetic transmission stirrer is provided with a water cooling device, so that the magnetic steel cannot be demagnetized even if the magnetic transmission stirrer runs in a high-temperature medium environment for a long time. The stirring paddle is of a cross propeller type, a plurality of oblique upward elliptic or circular paddles are arranged on the cross, and upward thrust is formed during rotation to achieve a better stirring effect. For a residual oil high-viscosity system, compared with the existing stirring time of more than 4 hours in a mode that the magnetic ring is driven by the magnetic ring to move up and down or a gravity ball stirring mode, the method only needs 1 hour of stirring time, greatly shortens the detection time, and improves the experimental efficiency. The balance main kettle and the balance auxiliary kettle respectively realize the rotation function of the reaction kettle body through the motor, and the reaction kettle is convenient to clean. The maximum tolerance temperature of the whole device reaches 320 ℃, the maximum tolerance pressure reaches 50MPa, and the phase equilibrium experiment can be carried out in a larger temperature and pressure range.

The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings, but the present invention is not limited thereto.

FIG. 1 is a schematic view showing a phase equilibrium measuring and separating apparatus according to a preferred embodiment of the present invention. FIG. 2 is a top view of the main equilibrium reactor. As can be seen in fig. 1 and 2, the phase equilibrium determination and separation apparatus comprises a feed and purge system, a main equilibrium tank 8, an auxiliary equilibrium tank 21 and a sampling system.

The feeding system and the cleaning system comprise a high-precision plunger pump 1, a washing liquid tank 2 and a solvent tank 3, wherein the high-precision plunger pump 1 controls feeding of a solvent and the washing liquid through pressure transmission liquid; outlets of the feeding system and the cleaning system are communicated with an inlet arranged at the upper part of the balance main kettle 8; the inlet is communicated with the balance space inside the balance main kettle 8; the outlet of the liquid washing tank 2 is also communicated with the outlet at the top of the main equilibrium reactor 8.

The balance space in the balance main kettle 8 consists of a balance kettle body and a window 7 at the top; the window is tightly arranged at the top of the balance main kettle by a pressing mechanism.

The balance auxiliary kettles 21 are communicated with the balance main kettle 8 through a top pipeline, and the main kettle and the auxiliary kettles can be mutually transferred.

The sampling system comprises a buffer tank 27, a gas flowmeter 28 and a gas collecting device 29 which are communicated in sequence; the buffer tank 27 is communicated with the outlet at the top of the balance auxiliary kettle 21.

The bottom of the balance main kettle 8 realizes the volume change through a balance main kettle piston 10, and a sealing ring is arranged between the balance main kettle piston 10 and the balance main kettle 8 cylinder; the balance auxiliary kettle 21 realizes variable volume through a balance auxiliary kettle piston 22, and a sealing ring is arranged between the balance auxiliary kettle piston 22 and a balance auxiliary kettle 21 cylinder.

A magnetic transmission stirrer 12 is arranged at the bottom of a piston 10 at the bottom of the balance main kettle 8, and a stirring blade 9 is arranged above the piston 10; the magnetic transmission stirring machine 12 is provided with a water cooling device, so that the magnetic steel can not be demagnetized even if the magnetic transmission stirring machine runs for a long time in a high-temperature medium environment. The piston 10 is provided with a support 26 to prevent the stirring blade 9 from being crushed when the piston 10 moves to the top of the balance main kettle 8. The stirring paddle 9 is of a cross propeller type, a plurality of oblique upward elliptic or circular paddles are arranged on the cross, and upward thrust is formed during rotation to achieve a better stirring effect.

The balance main kettle 8 and the balance auxiliary kettle 21 adopt stainless steel 316L as kettle body materials; the maximum enduring temperature of the balance main kettle 8 and the balance auxiliary kettle 21 is 320 ℃, and the maximum enduring pressure is 50 MPa.

A bottom piston 10 of the balance main kettle 8 is controlled by an adjusting screw rod to move up and down; the adjusting screw rod consists of a piston bracket 13, a nut 15 and a screw rod 14, and the screw rod 14 is controlled to rotate by a motor; the screw 14 is spaced from the piston 10 to allow room for the magnetic drive mixer 12; the piston 22 at the bottom of the balance auxiliary kettle 21 adopts a conventional screw rod adjusting mode.

The inlets and outlets of the balance main kettle 8 and the balance auxiliary kettle 21 are respectively provided with quick connectors 5, 6, 19 and 20; the balance main kettle 8 and the balance auxiliary kettle 21 are provided with brackets 18; the balance main kettle 8 and the balance auxiliary kettle 21 respectively realize the rotation function of the reaction kettle body through motors 17 and 25.

The balance main kettle 8 and the balance auxiliary kettle 21 are provided with temperature and pressure sensors; the balance main kettle 8 and the balance auxiliary kettle 21 adopt a semi-open type heat preservation sleeve 11 to control the temperature.

The invention provides a using method of a phase balance measuring and separating device, which comprises the following steps:

sucking the hydrocarbon mixture to be separated into a balance main kettle 8 by utilizing negative pressure, and measuring the feeding amount in a weighing mode; pressing the solvent in the solvent tank 3 into the balance main kettle 8 by using the high-precision plunger pump 1, and recording the pressure and the volume; heating the balance main kettle 8 to a reaction temperature, starting stirring, setting a piston of the balance main kettle 8 to be in a pressure maintaining mode, and maintaining the pressure to be a test pressure in the stirring process; a piston 22 of the balance auxiliary kettle 21 is pushed to the head to communicate the balance main kettle 8 with the balance auxiliary kettle 21, and the static phase splitting is carried out; sample transferring, wherein a piston of a balance main kettle 8 is set to be in a pressure maintaining mode, a piston of a balance auxiliary kettle 21 is set to be in a constant flow mode, the pressure fluctuation of the balance main kettle 8 is kept to be not more than +/-0.05 MPa in the sample transferring process, a phase interface is observed through a sapphire window 7, and the sample transferring is stopped when the phase interface moves to the top of the sapphire window 7; pushing the volume of the balance auxiliary kettle 21 to the maximum, and heating to completely gasify the light-phase solvent in the reaction kettle; opening an outlet valve at the top of the auxiliary balance kettle 21 and pushing a piston 22, collecting and metering the mass of the light-phase separation material through a buffer tank 27 and metering the volume of the light-phase solvent through a wet gas volume flowmeter 28; connecting the outlet 4 of the main balance kettle 8 with a new buffer tank 27, opening an outlet valve at the top of the main balance kettle 8 and pushing a piston 10, collecting and metering the mass of the heavy phase and the phase separation through the buffer tank, and metering the volume of the heavy phase and the solvent through a wet gas volume flowmeter 28; respectively pumping the washing liquid into the balance main kettle 8 and the balance auxiliary kettle 21 for cleaning and discharging; the washing solution is separated from the dissolved substance by distillation or the like and weighed and the washing solution is recovered.

The invention is further illustrated by the following preferred exemplary embodiments. The aim has been to better illustrate the invention and the scope of protection is not limited by the examples given.

Examples 1-3 illustrate the application and effects of the phase equilibrium measurement and separation apparatus provided by the present invention.

Example 1

The phase balance measuring and separating device shown in figure 1 is adopted, wherein the inner diameter of the balance space in the balance main kettle is 80mm, the height is 100mm, the window adopts a sapphire cylinder, the inner diameter is 10mm, and the height is 30 mm. The inner diameter of the balance auxiliary kettle is 100mm, and the height of the balance auxiliary kettle is 100 mm. The residual oil raw material is obtained from Wuhan division of China petrochemical company Limited, and the properties are shown in Table 1.

Sucking 120g of heated residual oil into a balance main kettle 8 by utilizing negative pressure; pressing the n-butane solvent in the solvent tank 3 into the balance main kettle 8 by using the high-precision plunger pump 1, and recording the feeding temperature, pressure and volume of the n-butane solvent; heating the balance main kettle 8 to the reaction temperature of 120 ℃, preserving heat, starting stirring, setting a piston of the balance main kettle 8 to be in a pressure maintaining 4MPa mode, and keeping the pressure to be 4MPa in the stirring process; after stirring for 1 hour, pushing a piston 22 of the balance auxiliary kettle 21 to the head, communicating the balance main kettle 8 with the balance auxiliary kettle 21, standing for 1 hour, and splitting phases; sample conversion is carried out, a piston of a balance main kettle 8 is set to be in a pressure maintaining mode of 4MPa, a piston of a balance auxiliary kettle 21 is set to be in a constant flow mode of 10mL/min, the pressure fluctuation of the balance main kettle 8 is kept to be not more than +/-0.05 MPa in the sample conversion process, a phase interface is observed through a sapphire window 7, and the sample conversion is stopped when the phase interface moves to the top of the sapphire window 7; pushing the volume of the balance auxiliary kettle 21 to the maximum to ensure that the light phase solvent in the reaction kettle is completely gasified; opening an outlet valve at the top of the auxiliary balance kettle 21 and slowly pushing a piston 22, collecting and metering the mass of the light phase separation material through a buffer tank 15 and metering the volume of the light phase solvent through a wet gas volume flowmeter 16; connecting an outlet 4 of the balance main kettle 8 with a buffer tank 15, opening an outlet valve at the top of the balance main kettle 8 and pushing a piston 10, collecting and metering the mass of heavy phase oil through the buffer tank, and metering the volume of a heavy phase solvent through a wet gas volume flowmeter 16; pumping the toluene washing liquid into a balance main kettle 8 and a balance auxiliary kettle 21 respectively to dissolve oil and discharging; the toluene washings were separated from the oil by distillation and weighed and recovered.

The phase equilibrium data obtained are shown in Table 2.

Example 2

The phase equilibrium measurement and separation apparatus, resid feed, and implementation steps used were the same as in example 1, except that the stirring time was 4 hours.

Example 3

The phase equilibrium measurement and separation apparatus, residual feedstock, and implementation procedures used were the same as in example 1, except that the test solvent was n-pentane, the test temperature was 220 ℃, the test pressure was 16MPa, and the resulting phase equilibrium data are shown in table 2.

Example 4

The residual oil raw material and the implementation steps are the same as those of the example 1, except that the adopted phase balance separation and measurement device is sequentially communicated with a feeding and cleaning system, a balance main kettle, a balance auxiliary kettle and a sampling system, wherein the balance main kettle adopts a gravity ball stirring mode, the gravity ball moves by rotating the balance main kettle to achieve the stirring purpose, and the stirring time is 4 hours. The phase equilibrium data obtained are shown in Table 2.

TABLE 1 residual feedstock Properties

TABLE 2

As can be seen from the data in Table 1, the phase equilibrium data of the embodiment 1, the embodiment 2 and the embodiment 4 are basically consistent, which shows that the method of the invention can shorten the phase equilibrium stirring time of the residual oil system to 1 hour, thereby greatly improving the experimental efficiency; example 3 shows that the method of the present invention can ensure that the phase equilibrium experiment can be carried out in a larger temperature and pressure range; the method is particularly suitable for phase equilibrium measurement and separation of high-viscosity systems.

Claims

1. A phase balance measuring and separating device comprises a feeding and cleaning system, a balance main kettle (8), a balance auxiliary kettle (21) and a sampling system which are communicated in sequence;

the balance main kettle consists of a balance space at the upper part and a volume adjusting structure at the bottom part, wherein the balance space is provided with a material inlet, a window (7) is arranged on the wall of the balance space, the top part of the balance main kettle is provided with an outlet, and the outlet of the balance main kettle is respectively communicated with the inlets of the balance auxiliary kettle and the sampling system;

2. The phase equilibrium measurement and separation apparatus according to claim 1, wherein the feed and cleaning system comprises a wash tank (2) and a solvent tank (3) connected in parallel, the outlet of the solvent tank is connected to the inlet of the equilibrium main vessel, the outlet of the wash tank is connected to the inlet of the equilibrium main vessel and the inlet of the equilibrium auxiliary vessel, the bottoms of the wash tank and the solvent tank are connected to the high-precision plunger pump (1), and the feeding of the solvent and the wash is controlled by the pressure transmission fluid.

3. The phase equilibrium measurement and separation apparatus according to claim 1, characterized in that the sampling system comprises a buffer tank (27), a gas flow meter (28) and a gas collection device (29) in serial communication.

4. Phase equilibrium measurement and separation apparatus according to claim 1, characterized in that the equilibrium main vessel material inlet is also in communication with the feed inlet (4).

5. The phase equilibrium measurement and separation apparatus of claim 1, wherein the window is a sapphire cylinder with an inner diameter of 5-20mm and a height of 20-50 mm; the window is hermetically connected with the top of the balance space of the balance main kettle;

preferably, the window is pressed at the top of the balance space by a pressing mechanism, and high-temperature and high-pressure resistant gaskets are arranged above and below the window.

6. The phase equilibrium measurement and separation apparatus according to claim 1, wherein the equilibrium space in the equilibrium main vessel has an inner diameter of 30 to 150mm and a height of 50 to 200 mm.

7. The phase equilibrium measurement and separation apparatus according to any one of claims 1 to 6, wherein the volume adjusting structure is a piston tightly coupled to the inner wall of the cylinder.

8. The phase equilibrium measuring and separating apparatus as set forth in claim 7, wherein a magnetic stirrer (12) is provided under the piston (10) at the bottom of the equilibrium main vessel; a stirring blade (9) of the magnetic transmission stirrer is arranged on the upper surface of the piston, a support (26) is arranged on the periphery of the stirring blade and fixed on the upper surface of the piston, and the height of the support is higher than that of the stirring blade.

9. The phase equilibrium measuring and separating apparatus as claimed in claim 8, wherein a water cooling means is provided outside the magnetically driven agitator.

10. The phase equilibrium measuring and separating device according to claim 8, characterized in that the stirring blades (9) are of the cross propeller type, the cross being provided with a plurality of obliquely upward elliptical or circular blades.

11. The phase balance measuring and separating device according to any one of claims 8 to 10, wherein the bottom of the piston at the bottom of the main balance kettle is connected with an adjusting screw, the adjusting screw of the main balance kettle is composed of a piston support (13), a fixed screw (14) and a nut (15), the piston support is movably fixed on the fixed screw through the nut, one end of the fixed screw is connected with the rotating shaft of the motor, and the other end of the fixed screw is provided with a gap with the bottom surface of the piston.

12. The phase balance measuring and separating device according to claim 7, wherein the bottom of the piston (22) at the bottom of the balance auxiliary kettle is connected with an adjusting lead screw, the adjusting lead screw of the balance auxiliary kettle consists of a kettle body bracket, a screw rod (24) contacted with the bottom of the piston and a nut (23), the screw rod is movably fixed on the kettle body bracket through the nut, and the other end of the screw rod is connected with a rotating shaft of a motor.

13. The phase equilibrium measurement and separation apparatus as claimed in any one of claims 1 to 6, 8 to 10 and 12, wherein the main equilibrium reactor and the auxiliary equilibrium reactor are made of stainless steel, and have a maximum withstand temperature of 320 ℃ and a maximum withstand pressure of 50 MPa.

14. The phase balance measuring and separating device according to claim 11 or 12, wherein the bottom of the balance main kettle and the balance auxiliary kettle is provided with a rotating structure, the rotating structure comprises a bracket (18), a rotating screw rod and a kettle body bracket, the bracket movably supports the rotating screw rod, one end of the rotating screw rod is fixedly connected with the kettle body bracket, and the other end of the rotating screw rod is connected with a kettle body rotating motor.

15. Phase equilibrium measurement and separation apparatus according to any of claims 1 to 6, 8 to 10, 12, characterized in that the equilibrium space of the equilibrium primary and secondary vessels is provided with temperature and pressure sensors.

16. The phase equilibrium measurement and separation apparatus according to claim 15, wherein the main equilibrium reactor and the auxiliary equilibrium reactor are externally provided with thermal insulation sleeves (11).

17. A method for phase equilibrium separation and determination of a hydrocarbon mixture, characterized in that a phase equilibrium determination and separation apparatus according to any one of claims 1 to 16 is used, comprising:

18. The method for separating and determining the phase equilibrium of a hydrocarbon mixture according to claim 17, wherein the hydrocarbon mixture to be separated is residual oil, and the solvent is one or a mixture of several of C3-C6 alkanes; the washing liquid is petroleum ether or toluene.

19. The method for the phase equilibrium separation and determination of a hydrocarbon mixture according to claim 17, wherein the phase separation operation temperature in the step (2) is 50 to 250 ℃ and the pressure is 3 to 20 MPa.