CN114425179B

CN114425179B - Phase balance measuring and separating device and application method thereof

Info

Publication number: CN114425179B
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: 2023-07-11
Anticipated expiration: 2040-09-02
Also published as: CN114425179A

Abstract

A phase balance measuring and separating device and an application method thereof, wherein 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 an upper balance space and a bottom volume adjusting structure, wherein the balance space is provided with a material inlet, a window is arranged on the wall of the balance space, the top 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; the balance auxiliary kettle consists of an upper balance space and a bottom volume adjusting structure, wherein 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 an interface, the manufacturing cost of the device is reduced, and the separation process of the light and heavy phases after extraction can be ensured not to influence the phase balance of the system.

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 high-temperature high-pressure phase balance measuring and separating device with a visible adjustable volume and a using method thereof.

Background

Solvent deasphalting technology is one of the important technologies for lightening heavy oil, and the combined process is an attractive development direction for maximizing the processing and utilization of heavy oil. Solvent deasphalting is a physical process of liquid-liquid extraction that separates components of the residuum according to their different solubilities. Although industrialization of solvent deasphalting process has been a very long history, because of extremely complex composition of residuum, properties of residuum from different sources are very different, and in order to accurately predict yield and product properties of deasphalted oil, reliable basic design data is provided, and basic research work such as residuum property analysis and phase balance must be performed. Many solvent deasphalting units are currently in operation, and there is a difficulty in optimizing their operation due to lack of research work on the basis of the application, which necessitates optimization of the process by modeling the deasphalting process mathematically. To model the solvent deasphalting process, studies must be made on the balance of physical property data and the deasphalting process. In addition, the phase volume and phase density basis data, which are important for solvent deasphalting tower design, are quite lacking.

The research of the phase equilibrium at present relates to various aspects of distillation, extraction, dissolution, recrystallization, purification, metallographic analysis and the like, and has extremely profound significance for scientific research and production of chemistry and chemical industry. The high-pressure visual phase balance kettle is a main instrument for researching thermodynamic phase balance and observing high-pressure reaction. One important method of observing high-pressure phase equilibrium, namely a variable volume static method, is to place the prepared raw materials in a balancing tank, regulate the temperature and pressure until two phases appear, and then sample the two phases. The pressure stability can be maintained by changing the system volume in the sampling process, so that the obtained phase balance data is more accurate than that of a constant volume static method, and more separated samples can be obtained for the next property analysis. In order to obtain basic data of phase equilibrium research, experimental equipment capable of measuring phase equilibrium data under the condition of high temperature and high pressure simultaneously exists is indispensable, however, at present, most of the phase equilibrium measuring devices adopting the domestic and foreign volume static method only can work under the condition of being lower than 200 ℃.

CN101021519a discloses a phase balance measuring device with high pressure and visual adjustable volume, which adopts a cylinder structure with a window, an adjusting bracket central shaft at the upper part of the cylinder is provided with an adjusting screw rod which is connected with a plunger in the cylinder to drive the plunger to move up and down in the cylinder; two ends of the bottom of the cylinder body are respectively externally connected with CO through a liquid outlet connector and a liquid inlet connector ₂ The fluid and feeding system is provided with a magnetic stirring controller at the lower part of the device. The measurement temperature reaches 200 ℃ and the pressure reaches 40MPa. CN101819170a discloses a non-integral variable volume high-voltage phase balanceThe measuring device fully utilizes the fixed volume phase balance tank, and adjusts the pressure of the whole system through an externally connected adjustable volume decompression container. CN205146108U discloses a rapid gas-liquid phase balancing device under high pressure condition, which belongs to the phase balancing of the 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 easily stabilized during the operation of the cyclic process. The recycling process has not been reported for use in residuum systems.

The prior art has the following disadvantages: (1) the detection time is long. The mode that the magnetic ring is driven to move up and down by the magnetic ring is adopted, so that stirring time of more than 4 hours is often needed for a residual oil high-viscosity system. (2) The cost of the fixed-volume visual phase balance kettle is high, and the sample quantity obtained by one experiment is too small. (3) The applicable temperature range is not wide, and most static phase balance measuring devices with the variable volume at home and abroad can only work at the temperature lower than 200 ℃. The invention aims to solve the problems.

Disclosure of Invention

The invention aims to solve the technical problems of providing a visual adjustable volume phase balance measuring and separating device suitable for high-temperature high-pressure conditions, and overcomes the defects of long time, high manufacturing cost and relatively low applicable temperature for achieving phase balance 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 above purpose, the present invention adopts the following technical scheme:

the 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 sequentially communicated;

the balance main kettle consists of an upper balance space and a bottom volume adjusting structure, wherein the balance space is provided with a material inlet, a window is arranged on the wall of the balance space, the top 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;

the balance auxiliary kettle consists of an upper balance space and a bottom volume adjusting structure, wherein 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 phase balance separation and determination method of hydrocarbon mixture, which adopts the phase balance determination and separation device and comprises the following steps:

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

(2) Heating the balance main kettle to an operation temperature, regulating the volume of the balance space to be unchanged, and standing to divide the mixture into an upper light phase and a lower heavy phase after the extraction and separation of the solvent and the hydrocarbon mixture are completed;

(3) The balance space volume of the balance auxiliary kettle is adjusted to be minimum, the balance main kettle and the balance auxiliary kettle are communicated, the balance space volume of the balance auxiliary kettle is increased, the pressure of the balance main kettle is kept, the light phase is transferred from the balance main kettle to the balance auxiliary kettle, and meanwhile, when the light phase is moved to the top of a window through a window observation phase interface, the transfer of samples is stopped;

(4) Regulating the balance space volume of the balance auxiliary kettle to be maximum, and heating to fully 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) The outlet of the balance main kettle is communicated with the sampling system, so that the volume of the balance space of the balance main kettle is reduced, and gas and heavy phase enter the sampling system;

(6) The feeding and cleaning system respectively introduces the washing liquid 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 have the beneficial effects that:

the phase balance measuring and separating device provided by the invention has the advantages that the movement condition of the interface is observed by adopting the window with relatively smaller inner diameter at the top of the balance main kettle, and the two-phase separation effect is good. The cost of the device is reduced, and a larger reaction space of the balance main kettle is provided to obtain more experimental separation samples for further property 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 the mutual sample conversion between the main kettle and the auxiliary kettle, and ensure that the phase balance of the system is not influenced in the separation process of the light phase and the heavy phase.

Drawings

FIG. 1 is a schematic diagram of one embodiment of a phase equilibrium determination and separation device.

FIG. 2 is a top view of the balance main tank.

Wherein:

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

5. 6, 19, 20-quick connector; 7-viewing window; 8-balancing a main kettle; 9-stirring paddles;

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

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

17. 25-a kettle body rotating motor; 18-a kettle body bracket; 21-balancing the auxiliary kettle; 26-supporting;

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

Detailed Description

The present application will be described in further detail below with reference to specific embodiments, it being understood that the embodiments described herein are for illustration and explanation of the present application only, and are not intended to limit the present invention in any way.

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

Unless otherwise indicated, 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 the ordinary understanding in the art, then the definition herein controls.

In this application, except where explicitly stated, any matters or matters not mentioned are directly applicable to those known in the art without modification. Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or ideas thus formed are all considered as 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 such combination would obviously be unreasonable to one skilled in the art.

Optionally, the feeding and cleaning system comprises a washing liquid tank 2 and a solvent tank 3 which are connected in parallel, wherein an outlet of the solvent tank is communicated with an inlet of the balance main kettle, an outlet of the washing liquid tank is communicated with an inlet of the balance main kettle and an inlet of the balance auxiliary kettle, bottoms of the washing liquid tank and the solvent tank are communicated with a 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 the 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 connected with the top of the balance space of the balance main kettle in a sealing way; preferably, the window is pressed on 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 50-200mm. The balance space is cylindrical or is in a truncated cone shape with the inner diameter reduced from bottom to top; the top of the balance space is provided with a sapphire cylinder window with a reduced pipe diameter.

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

Optionally, a magnetic drive stirrer 12 is arranged at the lower part of the piston 10 at the bottom of the balance main kettle; the stirring blade 9 of the magnetic transmission stirrer is arranged on the upper surface of the piston, the periphery of the stirring blade is provided with a support 26 which is fixed on the upper surface of the piston, and the height of the support is higher than that of the stirring blade. 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 stirrer. Ensuring that the magnetic steel does not demagnetize even if operated in a high temperature medium environment for a long time.

Optionally, the stirring blade is a cross propeller type, and a plurality of elliptical or circular blades obliquely upwards are arranged on the cross. The cross propeller type stirring blade is adopted to form upward thrust when rotating so as to achieve better stirring effect.

Optionally, the bottom of the piston at the bottom of the balance main kettle is connected with an adjusting screw rod, the adjusting screw rod of the balance main kettle consists of a piston bracket 13, a fixing screw rod 14 and a nut 15, the piston bracket is movably fixed on the fixing screw rod through the nut, one end of the fixing screw rod is connected with a rotating shaft of the motor, and a gap is reserved between the other end of the fixing 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 rod 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 and the magnetic transmission stirrer at the bottom of the piston is not smaller than the height of the balance space. The motor controls the screw 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 make room for a magnetically driven stirrer. The piston at the bottom of the balance auxiliary kettle adopts a conventional screw rod adjusting mode.

Optionally, the piston bottom of balanced vice cauldron bottom connect adjusting screw, balanced vice cauldron adjusting screw comprises cauldron body support, with the screw rod 24 and the nut 23 of piston bottom contact, the screw rod pass through the nut activity to be fixed on the cauldron body support, the screw rod other end connect the axis of rotation of motor.

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

Optionally, balanced main cauldron and balanced auxiliary kettle bottom be equipped with rotating-structure, rotating-structure constitute by support 18, rotation screw rod and cauldron body support, support activity support rotation screw rod, rotation screw rod one end with cauldron body support fixed connection, the axis of rotation of cauldron body rotating electrical machines is connected to the other end. The balance main kettle and the balance auxiliary kettle respectively realize the rotation function of the reaction kettle body through motors.

Optionally, the balance space of the balance main kettle and the balance auxiliary kettle is provided with temperature and pressure sensors;

optionally, insulation sleeves 11 are arranged outside the balance main kettle and the balance auxiliary kettle. More preferably, the temperature is controlled by a semi-open type heat preservation sleeve.

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

The invention provides a hydrocarbon mixture phase equilibrium separation and determination method, 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, and a new pipeline is preferably replaced to connect the balance main kettle with the sampling system, so that 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 separated matters is collected and measured through a buffer tank, and the gas volume is measured through a gas flowmeter.

In the phase balance determination and separation device and the use method thereof, 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 ℃ and the pressure is 3-20MPa.

The phase balance measuring and separating device and the application method thereof provided by the invention have the beneficial effects that the preferred embodiment is as follows:

the piston at the bottom of the balance main kettle of the phase balance measuring and separating device is coupled with a magnetic transmission stirrer; the magnetic drive stirrer is provided with a water cooling device, so that the magnetic steel can not be demagnetized even if the magnetic drive stirrer runs in a high-temperature medium environment for a long time. The stirring blade is a cross propeller type, a plurality of oval or round blades which are inclined upwards are arranged on the cross, and upward thrust is formed during rotation, so that a better stirring effect is achieved. For a residual oil high-viscosity system, compared with the stirring time of more than 4 hours in the existing stirring mode of driving a magnetic ring to move up and down or gravity ball stirring by a magnetic ring, the invention only needs 1 hour of stirring time, thereby greatly shortening the detection time and improving 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, so that the reaction kettle is convenient to clean. The highest tolerance temperature of the whole device reaches 320 ℃, the highest tolerance pressure reaches 50MPa, and the phase balance experiment can be carried out in a larger temperature and pressure range.

The following describes specific embodiments of the present invention in detail with reference to the drawings, but the present invention is not limited thereto.

In a preferred embodiment of the present invention, FIG. 1 is a schematic diagram of a phase equilibrium measuring and separating apparatus. FIG. 2 is a top view of the balance main tank. As can be seen in fig. 1 and 2, the phase equilibrium determination and separation device comprises a feed and cleaning system, a primary balancing tank 8, a secondary balancing 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 the feeding of solvent and washing liquid through pressure transmission liquid; the 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 a 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 balance main kettle 8.

The balance space inside 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 the pressing mechanism.

The balance auxiliary kettle 21 is communicated with the balance main kettle 8 through a top pipeline, and the main kettle and the auxiliary kettle can mutually change samples.

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

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

The bottom of a piston 10 at the bottom of the balance main kettle 8 is provided with a magnetic transmission stirrer 12, and stirring blades 9 are arranged above the piston 10; the magnetic drive stirrer 12 is provided with a water cooling device, so that the magnetic steel can be ensured not to be demagnetized even if the magnetic drive stirrer runs in a high-temperature medium environment for a long time. 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 balancing main tank 8. The stirring blade 9 is a cross propeller type, a plurality of oval or round blades which are inclined upwards are arranged on the cross, and upward thrust is formed during rotation to achieve better stirring effect.

The balance main kettle 8 and the balance auxiliary kettle 21 adopt stainless steel 316L as kettle body materials; the maximum withstand temperature of the balance main tank 8 and the balance sub tank 21 was 320℃and the maximum withstand pressure was 50MPa.

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

Quick connectors 5, 6, 19 and 20 are respectively arranged at the inlet and outlet of the balance main kettle 8 and the balance auxiliary kettle 21; 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 temperature of the balance main kettle 8 and the balance auxiliary kettle 21 is controlled by a semi-open type heat preservation sleeve 11.

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 the balance main kettle 8 by utilizing negative pressure, and measuring the feeding quantity by a weighing mode; the high-precision plunger pump 1 is utilized to press the solvent in the solvent tank 3 into the balance main kettle 8, and the pressure and the volume are recorded; heating the balance main kettle 8 to the reaction temperature, starting stirring, setting a piston of the balance main kettle 8 to a pressure maintaining mode, and keeping the pressure at the test pressure in the stirring process; the piston 22 of the balance auxiliary kettle 21 is pushed to the head, the balance main kettle 8 and the balance auxiliary kettle 21 are communicated, and the mixture is kept stand for phase separation; transferring samples, wherein a piston of the balance main kettle 8 is set to be in a pressure maintaining mode, a piston of the 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, meanwhile, a phase interface is observed through the sapphire window 7, and when the phase interface moves to the top of the sapphire window 7, sample transferring is stopped; pushing the volume of the balance auxiliary kettle 21 to the maximum, and heating to fully gasify the light phase solvent in the reaction kettle; opening the top outlet valve of the balance auxiliary kettle 21 and pushing the piston 22, collecting and metering the light phase separated matter mass through the buffer tank 27 and metering the light phase solvent volume through the wet gas volume flowmeter 28; connecting the outlet 4 of the balance main kettle 8 with a new buffer tank 27, opening an outlet valve at the top of the balance main kettle 8 and pushing a piston 10, collecting and measuring the mass of the heavy phase separated matters through the buffer tank and measuring the volume of the heavy phase solvent through a wet gas volume flowmeter 28; respectively pumping washing liquid into the balance main kettle 8 and the balance auxiliary kettle 21 for cleaning and discharging; the washing solution and the dissolved substance are separated and weighed by distillation or the like, and the washing solution is recovered.

The invention is further illustrated by the preferred exemplary embodiments below. The purpose of this invention is to better illustrate the content of the invention, and the scope of the invention is not limited by the examples.

Examples 1-3 illustrate the method and effect of using the phase equilibrium measuring and separating device 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 a balance space in a balance main kettle is 80mm, the height is 100mm, a window adopts a sapphire cylinder, the inner diameter is 10mm, and the height is 30mm. The inner diameter of the balance auxiliary kettle is 100mm, and the height is 100mm. The residue raw material used was taken from the chinese petrochemical company, martial arts, and the properties are shown in table 1.

Sucking 120g of heated residual oil into the balance main kettle 8 by utilizing negative pressure; pressing the normal 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 normal 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 a pressure maintaining 4MPa mode, and keeping the pressure at the test pressure of 4MPa in the stirring process; after stirring for 1 hour, pushing the piston 22 of the balance auxiliary kettle 21 to the head, communicating the balance main kettle 8 and the balance auxiliary kettle 21, standing for 1 hour and separating phases; the sample is transferred, a piston of the balance main kettle 8 is set to be in a pressure maintaining 4MPa mode, a piston of the balance auxiliary kettle 21 is set to be in a constant flow 10mL/min 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, meanwhile, a phase interface is observed through the sapphire window 7, and when the phase interface moves to the top of the sapphire window 7, sample transferring is stopped; pushing the volume of the balance auxiliary kettle 21 to the maximum so as to fully gasify the light phase solvent in the reaction kettle; opening an outlet valve at the top of the balance auxiliary kettle 21 and slowly pushing a piston 22, collecting and metering the light phase separated matter mass through a buffer tank 15 and metering the light phase solvent volume through a wet gas volume flow meter 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 the heavy phase oil through the buffer tank and metering the volume of the heavy phase solvent through a wet gas volume flowmeter 16; pumping toluene washing liquid into the balance main kettle 8 and the balance auxiliary kettle 21 respectively to dissolve oil and discharge; the toluene wash was weighed separately from the oil by distillation and the toluene wash was recovered.

The phase equilibrium data obtained are presented in Table 2.

Example 2

The phase equilibrium measuring and separating apparatus, residuum feed, and the procedure for carrying out the procedure were the same as in example 1, except that the stirring time was 4 hours.

Example 3

The phase equilibrium measuring and separating apparatus, residuum feed, and procedure for carrying out the same as in example 1 were carried out except that the test solvent was n-pentane, the test temperature was 220℃and the test pressure was 16MPa, and the obtained phase equilibrium data are shown in Table 2.

Example 4

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

TABLE 1 residuum feedstock Properties

TABLE 2

From the data in Table 1, the equilibrium data of examples 1, 2 and 4 are basically consistent, which shows that the method of the invention can shorten the 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 invention can ensure that phase equilibrium experiments are performed in a larger temperature and pressure range; the method is particularly suitable for phase equilibrium measurement and separation of a high-viscosity system.

Claims

1. The phase balance measuring and separating device is characterized by comprising a feeding and cleaning system, a balance main kettle (8), a balance auxiliary kettle (21) and a sampling system which are sequentially communicated;

the balance main kettle consists of an upper balance space and a bottom volume adjusting structure, wherein the inner diameter of the balance space of the balance main kettle is 30-150mm, and the height of the balance space is 50-200mm, a material inlet is arranged in the balance space of the balance main kettle, a window (7) is arranged on the wall of the balance space of the balance main kettle, an outlet is arranged at the top of the balance main kettle, and the outlet of the balance main kettle is respectively communicated with the inlets of the balance auxiliary kettle and the sampling system; the window is a sapphire cylinder with the inner diameter of 5-20mm and the height of 20-50 mm; the window is connected with the top of the balance space of the balance main kettle in a sealing way; the balance auxiliary kettle consists of an upper balance space and a bottom volume adjusting structure, wherein the balance space of the balance auxiliary kettle 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.

2. The phase balance measuring and separating device according to claim 1, wherein the feeding and cleaning system comprises a washing liquid tank (2) and a solvent tank (3) which are connected in parallel, wherein an outlet of the solvent tank is communicated with an inlet of the balance main kettle, an outlet of the washing liquid tank is communicated with an inlet of the material of the balance main kettle and an inlet of the balance auxiliary kettle, bottoms of the washing liquid tank and the solvent tank are communicated with a high-precision plunger pump (1), and feeding of the solvent and the washing liquid is controlled through pressure transmission liquid.

3. The phase balance measurement and separation device according to claim 1, wherein the sampling system comprises a buffer tank (27), a gas flow meter (28) and a gas collection device (29) which are connected in this order.

4. The phase equilibrium determination and separation apparatus of claim 1 wherein the equilibrium primary tank feed inlet is also in communication with the feed inlet (4).

5. The phase balance measuring and separating device according to claim 1, wherein the window is pressed on the top of the balance space of the balance main kettle by the pressing mechanism, and high-temperature and high-pressure resistant gaskets are arranged above and below the window.

6. A phase equilibrium determining and separating device according to any one of claims 1-5 wherein the volume-adjusting structure is a piston in close association with the inner wall of the cylinder.

7. The phase balance measuring and separating device according to claim 6, wherein the lower part of the piston (10) at the bottom of the balance main kettle is provided with a magnetic transmission stirrer (12); the 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.

8. The phase balance measuring and separating device according to claim 7, wherein a water cooling device is arranged outside the magnetic drive stirrer.

9. The phase balance measuring and separating device according to claim 7, characterized in that the stirring blade (9) is a cross propeller type, and a plurality of oval or round blades obliquely upwards are arranged on the cross.

10. The phase balance measuring and separating device according to any one of claims 7-9, wherein the bottom of the piston at the bottom of the balance main kettle is connected with an adjusting screw rod, the adjusting screw rod of the balance main kettle consists of a piston support (13), a fixing screw rod (14) and a nut (15), the piston support is movably fixed on the fixing screw rod through the nut, one end of the fixing screw rod is connected with a rotating shaft of a motor, and a gap is reserved between the other end of the fixing screw rod and the bottom surface of the piston.

11. The phase balance measuring and separating device according to claim 6, wherein the bottom of a piston (22) at the bottom of the balance auxiliary kettle is connected with an adjusting screw rod, the balance auxiliary kettle adjusting screw rod 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.

12. The phase equilibrium measuring and separating device according to any one of claims 1-5, 7-9, 11, wherein the balancing main tank and the balancing auxiliary tank are made of stainless steel, the highest withstanding temperature is 320 ℃, and the highest withstanding pressure is 50MPa.

13. The phase balance measuring and separating device according to claim 10, wherein the bottoms of the balance main kettle and the balance auxiliary kettle are provided with rotating structures, the rotating structures are composed of brackets (18), rotating screws and kettle body brackets, the brackets movably support the rotating screws, one ends of the rotating screws are fixedly connected with the kettle body brackets, and the other ends of the rotating screws are connected with a kettle body rotating motor.

14. The phase equilibrium determining and separating apparatus according to any one of claims 1 to 5, 7 to 9, 11, wherein the equilibrium space of the equilibrium main tank and the equilibrium sub tank is provided with temperature and pressure sensors.

15. The phase balance measuring and separating device according to claim 14, wherein the outside of the balance main kettle and the balance auxiliary kettle is provided with a heat preservation sleeve (11).

16. A method for phase-equilibrium separation and determination of a hydrocarbon mixture, characterized in that a phase-equilibrium determination and separation device according to any one of claims 1-15 is used, comprising:

(2) Heating the balance main kettle to an operating temperature, setting a piston of the balance main kettle into a pressure maintaining mode, and standing the mixture to be separated into an upper light phase and a lower heavy phase after the extraction and separation of the solvent and the hydrocarbon mixture are completed;

17. The method for phase-balanced separation and determination of a hydrocarbon mixture according to claim 16, wherein the hydrocarbon mixture to be separated is a residuum and the solvent is one or a mixture of several of C3-C6 alkanes; the washing liquid is petroleum ether or toluene.

18. The process for phase-balanced separation and determination of hydrocarbon mixtures according to claim 16, characterized in that the phase separation in step (2) is operated at a temperature of 50 to 250 ℃ and a pressure of 3 to 20MPa.