High-viscosity polymerization solution devolatilization system and process

Abstract

The invention discloses a high-viscosity polymerization solution devolatilization system. The high-viscosity polymerization solution devolatilization system comprises a first-stage flash heater, a first-stage flash tank distributor, a first-stage flash tank, a second-stage flash heater, a second-stage flash tank distributor, a second-stage flash tank, a third-stage flash tank distributor and a third-stage flash tank. The invention also provides a high-viscosity polymerization solution devolatilization process which is operated in the system. According to the high-viscosity polymerization solution devolatilization system and process provided by the invention, through static flash devolatilization, dynamic flash does not need to be introduced, and the energy consumption is relatively low; in the high-viscosity polymerization solution devolatilization process provided by the invention, the glue solution content in the polymer solution at the liquid phase outlet of the first-stage flash tank is 50-75% wt, the glue solution content in the polymer solution at the liquid phase outlet of the second-stage flash tank is 85-93% wt, the glue solution content in the polymer solution at the liquid phase outlet of the third-stage flash tank can reach 99.9% wt or more, and the devolatilization efficiency is high.

Description

Technical Field

[0001] The present invention relates to a devolatilization system and process for high-viscosity polymerization solutions. Background Art

[0002] The polyolefin elastomer (POE) plant mainly adopts a solution process, belonging to a high-viscosity polymerization solution system. The flash devolatilization system is one of the key components of its process, realizing the separation of polymers, solvents, and monomers. How to improve the devolatilization efficiency, increase the rubber content at the outlet of the flash tank, and separate the rubber liquid entrained in the flash vapor phase is an urgent problem to improve product quality and ensure the long-term stable operation of the plant.

[0003] Currently, in the prior art, the devolatilization process is divided into a static devolatilization process and a dynamic devolatilization process. The static devolatilization process, because its equipment has no external power, has a relatively simple structure, low energy consumption, and is economical and practical. Typical static devolatilization equipment includes flash type and falling-strip type devolatilization. The dynamic devolatilization process, that is, there are rotating components inside, and these components can force the high-viscosity material to be surface-renewed, so the heat transfer and mass transfer efficiency can be greatly improved, thereby obtaining a higher separation efficiency. The application of the dynamic devolatilization process is limited due to the high cost and high energy consumption of the equipment. Summary of the Invention

[0004] The present invention provides an effective, energy-saving, and safe devolatilization system and process for high-viscosity polymerization solutions, further improving the devolatilization efficiency of high-viscosity polymerization solutions. The devolatilization system for high-viscosity polymerization solutions provided by the present invention includes: a flash heater, a flash system, and a flash vapor separator system.

[0005] For the polyolefin elastomer (POE) system, due to the increase in the content of octene comonomer, the entanglement performance of the polymer solution is improved, resulting in a sharp increase in the surface tension and viscosity of the system and a decrease in the diffusion coefficient.

[0006] The devolatilization system and process for high-viscosity polymerization solutions provided by the present invention can improve the interface renewal ability and achieve low volatile residue of the polymer.

[0007] As an aspect of the present invention, it relates to a devolatilization system for high-viscosity polymerization solutions, and the system includes:

[0008] A primary flash heater (1), into which the high-viscosity polymerization solution enters for heating to obtain the heated material;

[0009] A primary flash tank distributor (2) and a primary flash tank (3), the heated material enters the primary flash tank (3), and after being dispersed by the primary flash tank distributor (2) at the top of the primary flash tank (3), it falls into the primary flash tank (3) for flashing. A primary flash vapor is obtained at the gas phase outlet of the primary flash tank (3), and a primary flash liquid is obtained at the liquid phase outlet of the primary flash tank (3);

[0010] A secondary flash heater (4). After adding a devolatilization aid to the primary flash liquid, it is heated by the secondary flash heater (4) to obtain a heated flash liquid.

[0011] A secondary flash tank distributor (5) and a secondary flash tank (6). The heated flash liquid enters the secondary flash tank (6). After being dispersed by the secondary flash tank distributor (5) at the top of the secondary flash tank (6), it falls into the secondary flash tank (6) for flashing. Secondary flash gas is obtained at the gas-phase outlet of the secondary flash tank (6), and secondary flash liquid is obtained at the liquid-phase outlet of the secondary flash tank (6).

[0012] A tertiary flash tank distributor (7) and a tertiary flash tank (8). The secondary flash liquid enters the tertiary flash tank (8). After being dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) for flashing. Tertiary flash gas is obtained at the gas-phase outlet of the tertiary flash tank (8), and tertiary flash liquid is obtained at the liquid-phase outlet of the tertiary flash tank (8). The tertiary flash liquid is the devolatilized high-viscosity polymer solution.

[0013] In a specific implementable embodiment, the above system further includes:

[0014] A primary flash gas-phase first separator (9) and a primary flash gas-phase second separator (10). The primary flash gas sequentially enters the primary flash gas-phase first separator (9) and the primary flash gas-phase second separator (10) to separate the liquid droplets entrained in the primary flash gas. The separated liquid phase returns to the primary flash tank (3).

[0015] A secondary flash gas-phase first separator (11) and a secondary flash gas-phase second separator (12). The secondary flash gas sequentially enters the secondary flash gas-phase first separator (11) and the secondary flash gas-phase second separator (12) to separate the liquid droplets entrained in the secondary flash gas. The separated liquid phase returns to the secondary flash tank (6).

[0016] A tertiary flash gas-phase first separator (13) and a tertiary flash gas-phase second separator (14). The tertiary flash gas sequentially enters the tertiary flash gas-phase first separator (13) and the tertiary flash gas-phase second separator (14) to separate the liquid droplets entrained in the tertiary flash gas.

[0017] In a specific implementable embodiment, the top of the tertiary flash tank (8) is directly connected to the liquid-phase outlet of the secondary flash tank (6) and is arranged vertically up and down.

[0018] As another aspect of the present invention, it relates to a devolatilization process for a high-viscosity polymer solution, which operates in the above system. The process includes:

[0019] (1) After the high-viscosity polymerization solution enters the first-stage flash heater (1) for heating, it is dispersed by the first-stage flash tank distributor (2) at the top of the first-stage flash tank (3) and then falls into the first-stage flash tank (3) in a filamentous form for flashing, obtaining first-stage flash gas and first-stage flash liquid;

[0020] (2) After adding a devolatilization aid to the first-stage flash liquid, it enters the second-stage flash heater (4) for heating, is dispersed by the first-stage flash tank distributor (5) at the top of the second-stage flash tank (6), and then falls into the second-stage flash tank (6) in a filamentous form for flashing, obtaining second-stage flash gas and second-stage flash liquid;

[0021] (3) The top of the third-stage flash tank (8) is directly connected to the liquid phase outlet of the second-stage flash tank (6). After the second-stage flash liquid is dispersed by the third-stage flash tank distributor (7) at the top of the third-stage flash tank (8), it falls into the third-stage flash tank (8) in a filamentous form for flash devolatilization, obtaining third-stage flash gas and third-stage flash liquid; the third-stage flash liquid is the devolatilized high-viscosity polymerization solution.

[0022] In a specific implementable manner, the above process further includes:

[0023] The first-stage flash gas sequentially enters the first-stage flash tank gas-phase first separator (9) and the first-stage flash tank gas-phase second separator (10) from the gas-phase outlet of the first-stage flash tank (3) to separate the liquid droplets entrained in the first-stage flash gas, and the separated liquid phase returns to the first-stage flash tank (3);

[0024] The second-stage flash gas sequentially enters the second-stage flash tank gas-phase first separator (11) and the second-stage flash tank gas-phase second separator (12) from the gas-phase outlet of the second-stage flash tank (6) to separate the liquid droplets entrained in the second-stage flash gas, and the separated liquid phase returns to the second-stage flash tank (6);

[0025] The third-stage flash gas enters the third-stage flash tank gas-phase separator (13) from the gas-phase outlet of the third-stage flash tank (8) to separate the liquid droplets entrained in the third-stage flash gas.

[0026] In a specific implementable manner, the operating pressure of the second-stage flash tank (6) is lower than the operating pressure of the first-stage flash tank (3).

[0027] In a specific implementable manner, the operating temperature of the first-stage flash heater (1) is 220°C to 233°C, and the operating pressure is 5.5 MPaG to 10.5 MPaG;

[0028] The operating temperature of the first-stage flash tank (3) is 150°C to 180°C, and the operating pressure is 0.6 MPaG to 0.8 MPaG.

[0029] In a specific embodiment, the operating temperature of the secondary flash heater (4) is 210°C to 230°C, and the operating pressure is 1.4 MPaG to 2.2 MPaG;

[0030] The operating temperature of the secondary flash tank (6) is 180°C to 206°C, and the operating pressure is 0.3 MPaG to 0.4 MPaG.

[0031] In a specific embodiment, the tertiary flash tank (8) operates under vacuum conditions, with an operating temperature of 220°C to 222°C and an operating pressure of 1 kPaA to 10 kPaA.

[0032] In a specific embodiment, the devolatilization aid is hexane.

[0033] The high-viscosity polymer solution devolatilization system and process provided by the present invention have at least the following technical advantages:

[0034] 1. The high-viscosity polymer solution devolatilization system and process provided by the present invention use static flash devolatilization, eliminating the need to introduce dynamic flash, resulting in lower energy consumption;

[0035] 2. The polymer melt in the high-viscosity polymer solution devolatilization process provided by the present invention has a larger specific surface area and changes the flow state of the melt, greatly improving the devolatilization efficiency; the mass percentage of the gum in the polymer solution at the liquid phase outlet of the primary flash tank (3) is 50% wt to 75% wt, the mass percentage of the gum in the polymer solution at the liquid phase outlet of the secondary flash tank (6) is 85% wt to 93% wt, and the mass percentage of the gum in the polymer solution at the liquid phase outlet of the tertiary flash tank (8) can reach more than 99.9%;

[0036] 3. The high-viscosity polymer solution devolatilization system provided by the present invention has a self-cleaning function, is safe and stable, and can operate in a long cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention.

[0038] Figure 1 It is a schematic diagram of the high-viscosity polymer solution devolatilization system disclosed in the embodiment of the present invention;

[0039] Among them, 1 is the first-stage flash heater, 2 is the first-stage flash tank distributor, 3 is the first-stage flash tank, 4 is the second-stage flash heater, 5 is the second-stage flash tank distributor, 6 is the second-stage flash tank, 7 is the third-stage flash tank distributor, 8 is the third-stage flash tank, 9 is the first gas-phase separator of the first-stage flash tank, 10 is the second gas-phase separator of the first-stage flash tank, 11 is the first gas-phase separator of the second-stage flash tank, 12 is the second gas-phase separator of the second-stage flash tank, and 13 is the gas-phase separator of the third-stage flash tank. Specific Embodiment

[0040] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings.

[0041] The first-stage flash heater and the second-stage flash heater in the high-viscosity polymer solution devolatilization system according to the embodiments of the present invention are based on the device disclosed in the utility model patent with the application number 2024214222868. The first-stage flash heater and the second-stage flash heater are heat exchange containers, having two temperature control chambers and a heat exchange chamber located between the two temperature control chambers. The heat exchange container is also provided with communication ports corresponding to each temperature control chamber. Polymer-related materials can enter the temperature control chambers to accumulate, prevent flow interruption, and have a certain temperature adjustment effect. The materials enter the heat exchange tubes in the temperature control chambers, and the heat exchange tubes are located in the heat exchange chamber. Then, the first heater introduces a heat exchange medium into the heat exchange chamber, which will heat the heat exchange tubes and the materials inside the tubes. The mixing elements in the heat exchange tubes have a partitioning structure for partitioning the space inside the heat exchange tubes. The partitioning structure connected to the heat exchange tubes by fixing parts partitions the materials to separate the agglomerated polymers, making the polymers evenly heated, which is beneficial to the subsequent devolatilization of the polymer materials, beneficial to improving the devolatilization efficiency of the polymers and the quality of the finally obtained polymers, and solves to a certain extent the technical problems that the devolatilization efficiency of the polymer materials and the quality of the obtained polymers are affected.

[0042] The first-stage flash tank distributor, the second-stage flash tank distributor, and the third-stage flash tank distributor in the high-viscosity polymer solution devolatilization system according to the embodiments of the present invention are based on the device disclosed in the utility model patent with the application number 2024214217770. The first-stage flash tank distributor, the second-stage flash tank distributor, and the third-stage flash tank distributor are strip-drop distribution devices. The materials of the polymer enter the cylinder body from the feeding end, and the system where the strip-drop distributor is located can apply pressure to the inside of the cylinder body to keep the materials in a pressurized state. The materials first fall to the damping distribution part located inside the cylinder body to expand the specific surface area of the materials, and then fall from the damping distribution part to the strip-drop end. Under the pressurized state, the materials are forced to pass through the strip-drop through holes and fall in a wire-like shape to achieve the purpose of polymer devolatilization.

[0043] The primary flash tank, the secondary flash tank and the tertiary flash tank in the high-viscosity polymer solution devolatilization system of the embodiment of the present invention are based on the device disclosed in the utility model patent with application number 2024205907211, and the primary flash tank, the secondary flash tank and the tertiary flash tank: include a gas-liquid separation tube and a tank body; the gas-liquid separation tube includes a main tube and a heat conduction tube; the main tube is arranged in the flash device, including an inner tube and a jacket, the jacket is connected to the inner tube by a sleeve arrangement, the first end of the inner tube and the first end of the jacket are used to be connected to the feed port of the flash device, and a heat conduction cavity is formed between the jacket and the inner tube; the heat conduction tube is used to introduce a hot fluid into the heat conduction cavity, and the heat conduction tube is connected to the heat conduction cavity; the first ends of the inner tube and the jacket are respectively connected to the feed port of the tank body; the separation time of the reaction product in the flash tank is increased, the components that are not fully separated are prevented from being lost from the gas phase outlet under the action of gas-liquid entrainment, and the high-viscosity liquid material after separation is prevented from adhering to the inner wall of the equipment, the liquid phase separation is more sufficient, and the flash separation effect and efficiency are improved.

[0044] The first-stage flash tank gas phase separator, the second-stage flash tank gas phase separator, the first-stage flash tank gas phase separator, the second-stage flash tank gas phase separator and the third-stage flash tank gas phase separator in the high-viscosity polymer solution devolatilization system of the embodiment of the present invention are based on the device disclosed in the utility model patent with application number 2024205904232, and the first-stage flash tank gas phase separator, the second-stage flash tank gas phase separator, the first-stage flash tank gas phase separator, the second-stage flash tank gas phase separator and the third-stage flash tank gas phase separator are process gas-gel liquid purification separators for flash systems, which are composed of an equipment body and a process pipe mouth. The equipment body is an inner and outer sleeve structure, and the inner and outer sleeves are fixedly connected by inner and outer pipes of a jacket flange and a connecting plate with a certain spiral inclination angle, and the spiral inclination angle of the spiral plate is 2-60°; a top cover with a spiral inclination angle is provided at the upper end of the inner cylinder; the cone connected to the lower part of the inner cylinder is connected to the liquid storage tank at the lower part of the cone through a pipe. The parts are connected by welding; the process gas enters the inner cylinder of the internal structure tangentially from the fluid inlet, and then spirals downward along the inner cylinder into the cone. During the rotation, the POE glue with higher density is thrown to the wall under the action of centrifugal force, and then flows along the wall into the liquid storage tank. The liquid storage tank is provided with a liquid level gauge port, which is connected to the automatic liquid level gauge and interlocked with the separation outlet. When the liquid level in the tank reaches a certain height, it is discharged from the separation outlet at the bottom of the tank; the separated and purified gas flows out of the device from the gas outlet on the upper part of the inner cylinder.

[0045] Example 1

[0046] Reference Figure 1 , high viscosity polymer solution devolatilization system, including:

[0047] Primary flash heater (1), primary flash tank distributor (2), primary flash tank (3), secondary flash heater (4), secondary flash tank distributor (5), secondary flash tank (6), tertiary flash tank distributor (7), tertiary flash tank (8), primary flash tank gas phase first separator (9), primary flash tank gas phase second separator (10), secondary flash tank gas phase first separator (11), secondary flash tank gas phase second separator (12) and tertiary flash tank gas phase separator (13);

[0048] Among them,

[0049] For the primary flash heater (1), the high-viscosity polymer solution enters the primary flash heater (1) for heating to obtain the heated material;

[0050] The primary flash tank distributor (2) and the primary flash tank (3), the heated material enters the primary flash tank (3), and after being dispersed by the primary flash tank distributor (2) at the top of the primary flash tank (3), it falls into the primary flash tank (3) in a filamentous form for flashing. The primary flash gas is obtained at the gas phase outlet of the primary flash tank (3), and the primary flash liquid is obtained at the liquid phase outlet of the primary flash tank (3);

[0051] For the secondary flash heater (4), after adding a stripping aid to the primary flash liquid, it is heated by the secondary flash heater (4) to obtain the heated flash liquid;

[0052] The secondary flash tank distributor (5) and the secondary flash tank (6), the heated flash liquid enters the secondary flash tank (6), and after being dispersed by the secondary flash tank distributor (5) at the top of the secondary flash tank (6), it falls into the secondary flash tank (6) in a filamentous form for flashing. The secondary flash gas is obtained at the gas phase outlet of the secondary flash tank (6), and the secondary flash liquid is obtained at the liquid phase outlet of the secondary flash tank (6);

[0053] The tertiary flash tank distributor (7) and the tertiary flash tank (8), the top of the tertiary flash tank (8) is directly connected to the liquid phase outlet of the secondary flash tank (6). The secondary flash liquid enters the tertiary flash tank (8), and after being dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) in a filamentous form for flashing. The tertiary flash gas is obtained at the gas phase outlet of the tertiary flash tank (8), and the tertiary flash liquid is obtained at the liquid phase outlet of the tertiary flash tank (8); The tertiary flash liquid is the high-viscosity polymer solution after stripping;

[0054] The first separator (9) and the second separator (10) for the first-stage flash vapor phase. The first-stage flash vapor enters the first separator (9) and the second separator (10) of the first-stage flash vapor phase in sequence to separate the liquid droplets entrained in the first-stage flash vapor. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the first-stage flash tank (3);

[0055] The first separator (11) and the second separator (12) for the second-stage flash vapor phase. The second-stage flash vapor enters the first separator (11) and the second separator (12) of the second-stage flash vapor phase in sequence to separate the liquid droplets entrained in the second-stage flash vapor. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the second-stage flash tank (6);

[0056] The first separator (13) and the second separator (14) for the third-stage flash vapor phase. The third-stage flash vapor enters the first separator (13) and the second separator (14) of the third-stage flash vapor phase in sequence to separate the liquid droplets entrained in the third-stage flash vapor. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase is collected and sold externally.

[0057] The devolatilization process of the high-viscosity polymer solution operates in the above high-viscosity polymer solution devolatilization system:

[0058] In this embodiment, the high-viscosity polymer solution is a polymerization reaction material (octene grade, melt index ≤ 5), and the polymerization reaction material is the reaction product of ethylene and 1-octene in the presence of hexane (solvent).

[0059] (1) The high-viscosity polymer solution enters the first-stage flash heater (1) for heating. The first-stage flash heater (1) operates at an operating temperature of 233 °C and an operating pressure of 5.5 MPaG to obtain the heated material. The heated material is dispersed by the first-stage flash tank distributor (2) at the top of the first-stage flash tank (3) and then falls into the first-stage flash tank (3) in a filamentous form for flash evaporation to obtain the first-stage flash vapor and the first-stage flash liquid. The first-stage flash tank (3) operates at an operating temperature of 180 °C and an operating pressure of 0.7 MPaG. The first-stage flash vapor sequentially enters the first separator (9) and the second separator (10) for the first-stage flash vapor phase from the gas phase outlet of the first-stage flash tank (3) to separate the liquid droplets entrained in the first-stage flash vapor. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the first-stage flash tank (3). The first-stage flash liquid is the polymer solution at the liquid phase outlet of the first-stage flash tank (3), and the content of the glue solution is 50% wt (mass percentage).

[0060] (2) After adding hexane (a devolatilization aid) to the primary flash liquid obtained in step (1), it enters the secondary flash heater (4) for heating. The secondary flash heater (4) operates at an operating temperature of 227 °C and an operating pressure of 1.4 MPaG to obtain the heated flash liquid. The heated flash liquid is dispersed by the secondary flash tank distributor (5) at the top of the secondary flash tank (6) and then falls into the secondary flash tank (6) in a filamentous form for flashing, obtaining secondary flash gas and secondary flash liquid. The secondary flash tank (6) operates at a lower operating pressure than the primary flash tank (3). The secondary flash tank (6) operates at an operating temperature of 200 °C and an operating pressure of 0.3 MPaG. The secondary flash gas sequentially enters the first separator (11) for the gas phase of the secondary flash tank and the second separator (12) for the gas phase of the secondary flash tank from the gas phase outlet of the secondary flash tank (6) to separate the liquid droplets entrained in the secondary flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the secondary flash tank (6). The secondary flash liquid is a polymer solution at the liquid phase outlet of the secondary flash tank (6), and the content of the glue solution is 85% wt (mass percentage).

[0061] (3) The top of the tertiary flash tank (8) is directly connected to the liquid phase outlet of the secondary flash tank (6), and the material flow direction is step by step lower. The secondary flash tank (6) and the tertiary flash tank (8) are vertically arranged. The secondary flash liquid is transported into the tertiary flash tank (8) through the pressure difference between the secondary flash tank (6) and the tertiary flash tank (8). After being dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) in a filamentous form for flashing, obtaining tertiary flash gas and tertiary flash liquid. The tertiary flash tank (8) operates under vacuum conditions, with an operating temperature of 220 °C and an operating pressure of 10 kPaA. The tertiary flash gas enters the tertiary flash tank gas separator (13) from the gas phase outlet of the tertiary flash tank (8) to separate the liquid droplets entrained in the tertiary flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase is collected and sold externally. The tertiary flash liquid is a polymer solution at the liquid phase outlet of the tertiary flash tank (8), and the content of the glue solution is 99.9% wt (mass percentage).

[0062] Example 2

[0063] Refer to Figure 1 , the devolatilization system for high-viscosity polymer solution in this example is the same as that in Example 1.

[0064] The devolatilization process of the high-viscosity polymer solution operates in the above devolatilization system for high-viscosity polymer solution:

[0065] The high-viscosity polymerization solution described in this embodiment is a polymerization reaction material (octene grade, 5 < melt index ≤ 14), and the polymerization reaction material is the reaction product of ethylene and 1-octene in the presence of hexane (solvent).

[0066] (1) The high-viscosity polymerization solution enters the first-stage flash heater (1) for heating. The first-stage flash heater (1) operates at an operating temperature of 230 °C and an operating pressure of 5.5 MPaG to obtain the heated material. After being dispersed by the first-stage flash tank distributor (2) at the top of the first-stage flash tank (3), the heated material falls into the first-stage flash tank (3) in a filamentous form for flashing, obtaining the first-stage flash gas and the first-stage flash liquid. The first-stage flash tank (3) operates at an operating temperature of 170 °C and an operating pressure of 0.6 MPaG. The first-stage flash gas sequentially enters the first-stage flash tank gas-phase first separator (9) and the first-stage flash tank gas-phase second separator (10) from the gas-phase outlet of the first-stage flash tank (3) to separate the liquid droplets entrained in the first-stage flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the first-stage flash tank (3). The first-stage flash liquid is the polymer solution at the liquid-phase outlet of the first-stage flash tank (3), and the content of the gum solution is 65% wt (mass percentage).

[0067] (2) After adding hexane (auxiliary devolatilization agent) to the first-stage flash liquid obtained in step (1), it enters the second-stage flash heater (4) for heating. The second-stage flash heater (4) operates at an operating temperature of 230 °C and an operating pressure of 1.4 MPaG to obtain the heated flash liquid. After being dispersed by the second-stage flash tank distributor (5) at the top of the second-stage flash tank (6), the heated flash liquid falls into the second-stage flash tank (6) in a filamentous form for flashing, obtaining the second-stage flash gas and the second-stage flash liquid. The second-stage flash tank (6) operates at a pressure lower than that of the first-stage flash tank (3), and the second-stage flash tank (6) operates at an operating temperature of 206 °C and an operating pressure of 0.3 MPaG. The second-stage flash gas sequentially enters the second-stage flash tank gas-phase first separator (11) and the second-stage flash tank gas-phase second separator (12) from the gas-phase outlet of the second-stage flash tank (6) to separate the liquid droplets entrained in the second-stage flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the second-stage flash tank (6). The second-stage flash liquid is the polymer solution at the liquid-phase outlet of the second-stage flash tank (6), and the content of the gum solution is 90% wt (mass percentage).

[0068] (3) The top of the tertiary flash tank (8) is directly connected to the liquid phase outlet of the secondary flash tank (6), and the material flow direction is step by step downward. The secondary flash tank (6) and the tertiary flash tank (8) are vertically arranged. The secondary flash liquid is transported into the tertiary flash tank (8) through the pressure difference between the secondary flash tank (6) and the tertiary flash tank (8). After being dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) in a filamentous state for flashing, obtaining tertiary flash vapor and tertiary flash liquid; the tertiary flash tank (8) operates under vacuum conditions, with an operating temperature of 222 °C and an operating pressure of 1 kPaA; the tertiary flash vapor enters the tertiary flash tank gas separator (13) from the gas phase outlet of the tertiary flash tank (8) to separate the liquid droplets entrained in the tertiary flash vapor. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase is collected and sold externally; the tertiary flash liquid is the polymer solution at the liquid phase outlet of the tertiary flash tank (8), and the content of the glue solution is 99.97% wt (mass percentage).

[0069] Example 3

[0070] Refer to Figure 1 , the high-viscosity polymer solution devolatilization system of this example is the same as that of Example 1.

[0071] The high-viscosity polymer solution devolatilization process operates in the above high-viscosity polymer solution devolatilization system:

[0072] In this example, the high-viscosity polymer solution is the polymerization reaction material (octene grade, melt index > 14), and the polymerization reaction material is the reactant of ethylene and 1-octene in the presence of hexane (solvent).

[0073] (1) The high-viscosity polymer solution enters the primary flash heater (1) for heating. The primary flash heater (1) operates at an operating temperature of 230 °C and an operating pressure of 5.5 MPaG to obtain the heated material; the heated material is dispersed by the primary flash tank distributor (2) at the top of the primary flash tank (3) and then falls into the primary flash tank (3) in a filamentous state for flashing, obtaining primary flash vapor and primary flash liquid. The primary flash tank (3) operates at an operating temperature of 155 °C and an operating pressure of 0.6 MPaG; the primary flash vapor sequentially enters the primary flash tank gas first separator (9) and the primary flash tank gas second separator (10) from the gas phase outlet of the primary flash tank (3) to separate the liquid droplets entrained in the primary flash vapor. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the primary flash tank (3); the primary flash liquid is the polymer solution at the liquid phase outlet of the primary flash tank (3), and the content of the glue solution is 75% wt (mass percentage).

[0074] (2) After adding hexane (a devolatilization aid) to the primary flash liquid obtained in step (1), it enters the secondary flash heater (4) for heating. The secondary flash heater (4) operates at an operating temperature of 230°C and an operating pressure of 1.4 MPaG to obtain the heated flash liquid. The heated flash liquid is dispersed by the secondary flash tank distributor (5) at the top of the secondary flash tank (6) and then falls into the secondary flash tank (6) in a filamentous form for flashing, obtaining secondary flash gas and secondary flash liquid. The secondary flash tank (6) operates at a lower operating pressure than the primary flash tank (3). The secondary flash tank (6) operates at an operating temperature of 200°C and an operating pressure of 0.3 MPaG. The secondary flash gas sequentially enters the first separator (11) for the gas phase of the secondary flash tank and the second separator (12) for the gas phase of the secondary flash tank from the gas phase outlet of the secondary flash tank (6) to separate the liquid droplets entrained in the secondary flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the secondary flash tank (6). The secondary flash liquid is the polymer solution at the liquid phase outlet of the secondary flash tank (6), and the content of the glue solution is 93% wt (mass percentage).

[0075] (3) The top of the tertiary flash tank (8) is directly connected to the liquid phase outlet of the secondary flash tank (6), and the material flow direction is step by step lower. The secondary flash tank (6) and the tertiary flash tank (8) are vertically arranged. The secondary flash liquid is transported into the tertiary flash tank (8) through the pressure difference between the secondary flash tank (6) and the tertiary flash tank (8). After being dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) in a filamentous form for flashing, obtaining tertiary flash gas and tertiary flash liquid. The tertiary flash tank (8) operates under vacuum conditions. The tertiary flash tank (8) operates at an operating temperature of 222°C and an operating pressure of 1 kPaA. The tertiary flash tank (8) operates under vacuum conditions, with an operating temperature of 220°C and an operating pressure of 10 kPaA. The tertiary flash gas enters the tertiary flash tank gas separator (13) from the gas phase outlet of the tertiary flash tank (8) to separate the liquid droplets entrained in the tertiary flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase is collected and sold externally. The tertiary flash liquid is the polymer solution at the liquid phase outlet of the tertiary flash tank (8), and the content of the glue solution is 99.97% wt (mass percentage).

[0076] Example 4

[0077] Refer to Figure 1 , the devolatilization system for high-viscosity polymer solution in this example is the same as that in Example 1.

[0078] The devolatilization process of high-viscosity polymer solution operates in the above devolatilization system for high-viscosity polymer solution:

[0079] In this embodiment, the high-viscosity polymerization solution is a polymerization reaction material (butene grade, melt index ≤ 5), and the polymerization reaction material is a reaction product of ethylene and 1-butene in the presence of hexane (solvent).

[0080] (1) The high-viscosity polymerization solution enters the first-stage flash heater (1) for heating. The first-stage flash heater (1) operates at an operating temperature of 220°C and an operating pressure of 10 MPaG to obtain the heated material. After being dispersed by the first-stage flash tank distributor (2) at the top of the first-stage flash tank (3), the heated material falls into the first-stage flash tank (3) in a filamentous form for flashing, obtaining the first-stage flash gas and the first-stage flash liquid. The first-stage flash tank (3) operates at an operating temperature of 160°C and an operating pressure of 0.8 MPaG. The first-stage flash gas sequentially enters the first-stage flash tank gas-phase first separator (9) and the first-stage flash tank gas-phase second separator (10) from the gas-phase outlet of the first-stage flash tank (3) to separate the liquid droplets entrained in the first-stage flash gas. The separated gas-phase enters the monomer recovery unit for recovery, and the separated liquid-phase returns to the first-stage flash tank (3). The first-stage flash liquid is the polymer solution at the liquid-phase outlet of the first-stage flash tank (3), and the content of the gum solution is 65% wt (mass percentage).

[0081] (2) After adding hexane (auxiliary devolatilization agent) to the first-stage flash liquid obtained in step (1), it enters the second-stage flash heater (4) for heating. The second-stage flash heater (4) operates at an operating temperature of 210°C and an operating pressure of 2.2 MPaG to obtain the heated flash liquid. After being dispersed by the second-stage flash tank distributor (5) at the top of the second-stage flash tank (6), the heated flash liquid falls into the second-stage flash tank (6) in a filamentous form for flashing, obtaining the second-stage flash gas and the second-stage flash liquid. The second-stage flash tank (6) operates at an operating pressure lower than that of the first-stage flash tank (3). The second-stage flash tank (6) operates at an operating temperature of 180°C and an operating pressure of 0.4 MPaG. The second-stage flash gas sequentially enters the second-stage flash tank gas-phase first separator (11) and the second-stage flash tank gas-phase second separator (12) from the gas-phase outlet of the second-stage flash tank (6) to separate the liquid droplets entrained in the second-stage flash gas. The separated gas-phase enters the monomer recovery unit for recovery, and the separated liquid-phase returns to the second-stage flash tank (6). The second-stage flash liquid is the polymer solution at the liquid-phase outlet of the second-stage flash tank (6), and the content of the gum solution is 90% wt (mass percentage).

[0082] (3) The top of the third - stage flash tank (8) is directly connected to the liquid - phase outlet of the second - stage flash tank (6), and the material flow direction is step - by - step downward. The second - stage flash tank (6) and the third - stage flash tank (8) are vertically arranged. The second - stage flash liquid is transported into the third - stage flash tank (8) through the pressure difference between the second - stage flash tank (6) and the third - stage flash tank (8). After being dispersed by the third - stage flash tank distributor (7) at the top of the third - stage flash tank (8), it falls into the third - stage flash tank (8) in a filamentous form for flashing, obtaining third - stage flash gas and third - stage flash liquid. The third - stage flash tank (8) operates under vacuum conditions, with an operating temperature of 220 °C and an operating pressure of 10 kPaA. The third - stage flash gas enters the third - stage flash tank gas - phase separator (13) from the gas - phase outlet of the third - stage flash tank (8) to separate the liquid droplets entrained in the third - stage flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase is collected and sold externally. The third - stage flash liquid is a polymer solution at the liquid - phase outlet of the third - stage flash tank (8), and the content of the glue solution is 99.9% wt (mass percentage).

[0083] Example 5

[0084] Refer to Figure 1 , the high - viscosity polymer solution devolatilization system of this example is the same as that of Example 1.

[0085] The high - viscosity polymer solution devolatilization process operates in the above - mentioned high - viscosity polymer solution devolatilization system:

[0086] In this example, the high - viscosity polymer solution is a polymerization reaction material (butene grade, melt index ≥ 5), and the polymerization reaction material is the reaction product of ethylene and 1 - butene in the presence of hexane (solvent).

[0087] (1) The high - viscosity polymer solution enters the first - stage flash heater (1) for heating. The first - stage flash heater (1) operates at an operating temperature of 220 °C and an operating pressure of 10.5 MPaG to obtain the heated material. After being dispersed by the first - stage flash tank distributor (2) at the top of the first - stage flash tank (3), it falls into the first - stage flash tank (3) in a filamentous form for flashing, obtaining first - stage flash gas and first - stage flash liquid. The first - stage flash tank (3) operates at an operating temperature of 150 °C and an operating pressure of 0.7 MPaG. The first - stage flash gas enters the first - stage flash tank gas - phase first separator (9) and the first - stage flash tank gas - phase second separator (10) in sequence from the gas - phase outlet of the first - stage flash tank (3) to separate the liquid droplets entrained in the first - stage flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the first - stage flash tank (3). The first - stage flash liquid is a polymer solution at the liquid - phase outlet of the first - stage flash tank (3), and the content of the glue solution is 75% wt (mass percentage).

[0088] (2) After adding hexane (a stripping agent) to the primary flash liquid obtained in step (1), it enters the secondary flash heater (4) for heating. The secondary flash heater (4) operates at an operating temperature of 210 °C and an operating pressure of 2.2 MPaG to obtain the heated flash liquid. The heated flash liquid is dispersed by the secondary flash tank distributor (5) at the top of the secondary flash tank (6) and then falls into the secondary flash tank (6) in a filamentous form for flashing, obtaining secondary flash gas and secondary flash liquid. The secondary flash tank (6) operates at an operating pressure lower than that of the primary flash tank (3). The secondary flash tank (6) operates at an operating temperature of 180 °C and an operating pressure of 0.4 MPaG. The secondary flash gas successively enters the first separator (11) for the gas phase of the secondary flash tank and the second separator (12) for the gas phase of the secondary flash tank from the gas phase outlet of the secondary flash tank (6) to separate the liquid droplets entrained in the secondary flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the secondary flash tank (6). The secondary flash liquid is the polymer solution at the liquid phase outlet of the secondary flash tank (6), and the content of the glue solution is 90% wt (mass percentage).

[0089] (3) The top of the tertiary flash tank (8) is directly connected to the liquid phase outlet of the secondary flash tank (6), and the material flow direction is step by step lower. The secondary flash tank (6) and the tertiary flash tank (8) are vertically arranged. The secondary flash liquid is transported into the tertiary flash tank (8) through the pressure difference between the secondary flash tank (6) and the tertiary flash tank (8). After being dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) in a filamentous form for flashing, obtaining tertiary flash gas and tertiary flash liquid. The tertiary flash tank (8) operates under vacuum conditions, with an operating temperature of 220 °C and an operating pressure of 1 kPaA. The tertiary flash gas enters the tertiary flash tank gas separator (13) from the gas phase outlet of the tertiary flash tank (8) to separate the liquid droplets entrained in the tertiary flash gas. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase is collected and sold externally. The tertiary flash liquid is the polymer solution at the liquid phase outlet of the tertiary flash tank (8), and the content of the glue solution is 99.97% wt (mass percentage).

[0090] As can be seen from the above embodiments, in the devolatilization system and process of the high-viscosity polymerization solution in Embodiments 1-5, the mass percentage content of the glue liquid in the polymer solution at the outlet of the first-stage flash tank (3) is 50% wt to 75% wt, the mass percentage content of the glue liquid in the polymer solution at the outlet of the second-stage flash tank (6) is 85% wt to 93% wt, and the mass percentage content of the glue liquid in the polymer solution at the outlet of the third-stage flash tank (8) is above 99.9%; the devolatilization efficiency of the devolatilization system and process of the high-viscosity polymerization solution provided by the embodiments of the present invention is high, and the devolatilization system and process provided by the embodiments of the present invention adopt static flash devolatilization, without introducing dynamic flash, and the energy consumption is low.

[0091] In the high-viscosity polymerization solution devolatilization system provided by the present invention, the first-stage flash distributor can increase the surface renewal of the material; the second-stage flash distributor can increase the foaming probability and mass transfer area, and strengthen the devolatilization process; the third-stage flash distributor can increase the film-forming area and improve the devolatilization efficiency.

[0092] The devolatilization process of the high-viscosity polymerization solution in Embodiments 1-5 can be summarized as follows:

[0093] (1) After the high-viscosity polymerization solution enters the first-stage flash heater (1) for heating, it is dispersed by the first-stage flash tank distributor (2) at the top of the first-stage flash tank (3), and then falls into the first-stage flash tank (3) in a filamentous form for flash evaporation, obtaining the first-stage flash vapor and the first-stage flash liquid;

[0094] (2) After adding an auxiliary devolatilization agent to the first-stage flash liquid, it enters the second-stage flash heater (4) for heating, is dispersed by the first-stage flash tank distributor (5) at the top of the second-stage flash tank (6), and then falls into the second-stage flash tank (6) in a filamentous form for flash evaporation, obtaining the second-stage flash vapor and the second-stage flash liquid;

[0095] (3) The top of the third-stage flash tank (8) is directly connected to the liquid phase outlet of the second-stage flash tank (6). After the second-stage flash liquid is dispersed by the third-stage flash tank distributor (7) at the top of the third-stage flash tank (8), it falls into the third-stage flash tank (8) in a filamentous form for flash devolatilization, obtaining the third-stage flash vapor and the third-stage flash liquid; the third-stage flash liquid is the devolatilized high-viscosity polymerization solution.

[0096] The above process further includes:

[0097] The first-stage flash vapor sequentially enters the first-stage flash tank gas-phase first separator (9) and the first-stage flash tank gas-phase second separator (10) from the gas-phase outlet of the first-stage flash tank (3) to separate the liquid droplets entrained in the first-stage flash vapor. The separated gas phase enters the monomer recovery unit for recovery, and the separated liquid phase returns to the first-stage flash tank (3);

[0098] The secondary flash vapor enters the first gas-phase separator (11) of the secondary flash tank and the second gas-phase separator (12) of the secondary flash tank in sequence from the gas-phase outlet of the secondary flash tank (6), to separate the liquid droplets entrained in the secondary flash vapor. The separated gas-phase enters the monomer recovery unit for recovery, and the separated liquid-phase returns to the secondary flash tank (6).

[0099] The tertiary flash vapor enters the gas-phase separator (13) of the tertiary flash tank from the gas-phase outlet of the tertiary flash tank (8) to separate the liquid droplets entrained in the tertiary flash vapor. The separated gas-phase enters the monomer recovery unit for recovery, and the separated liquid-phase is collected and sold externally.

[0100] Among them,

[0101] The operating pressure of the secondary flash tank (6) is lower than that of the primary flash tank (3).

[0102] The operating temperature of the primary flash heater (1) is 220°C to 233°C, and the operating pressure is 5.5 MPaG to 10.5 MPaG;

[0103] The operating temperature of the primary flash tank (3) is 150°C to 180°C, and the operating pressure is 0.6 MPaG to 0.8 MPaG;

[0104] The operating temperature of the secondary flash heater (4) is 210°C to 230°C, and the operating pressure is 1.4 MPaG to 2.2 MPaG;

[0105] The operating temperature of the secondary flash tank (6) is 180°C to 206°C, and the operating pressure is 0.3 MPaG to 0.4 MPaG;

[0106] The tertiary flash tank (8) operates under vacuum conditions, with an operating temperature of 220°C to 222°C and an operating pressure of 1 kPaA to 10 kPaA.

[0107] Among them, the stripping aid is hexane.

Claims

1. High-viscosity polymer solution devolatilization system, characterized in that, The system includes: A primary flash heater (1), into which a high-viscosity polymer solution enters for heating to obtain a heated material; A primary flash tank distributor (2) and a primary flash tank (3), the heated material enters the primary flash tank (3), and after being dispersed by the primary flash tank distributor (2) at the top of the primary flash tank (3), it falls into the primary flash tank (3) for flashing. A primary flash gas is obtained at the gas-phase outlet of the primary flash tank (3), and a primary flash liquid is obtained at the liquid-phase outlet of the primary flash tank (3); A secondary flash heater (4), after a stripping aid is added to the primary flash liquid, it is heated by the secondary flash heater (4) to obtain a heated flash liquid; A secondary flash tank distributor (5) and a secondary flash tank (6), the heated flash liquid enters the secondary flash tank (6), and after being dispersed by the secondary flash tank distributor (5) at the top of the secondary flash tank (6), it falls into the secondary flash tank (6) for flashing. A secondary flash gas is obtained at the gas-phase outlet of the secondary flash tank (6), and a secondary flash liquid is obtained at the liquid-phase outlet of the secondary flash tank (6); A tertiary flash tank distributor (7) and a tertiary flash tank (8), the secondary flash liquid enters the tertiary flash tank (8), and after being dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) for flashing. A tertiary flash gas is obtained at the gas-phase outlet of the tertiary flash tank (8), and a tertiary flash liquid is obtained at the liquid-phase outlet of the tertiary flash tank (8); the tertiary flash liquid is the polymer solution with volatiles removed.

2. The high-viscosity polymer solution devolatilization system according to claim 1, characterized in that, The system further includes: A primary flash gas phase first separator (9) and a primary flash gas phase second separator (10), the primary flash gas sequentially enters the primary flash gas phase first separator (9) and the primary flash gas phase second separator (10) to separate the liquid droplets entrained in the primary flash gas, and the separated liquid phase returns to the primary flash tank (3); A secondary flash gas phase first separator (11) and a secondary flash gas phase second separator (12), the secondary flash gas sequentially enters the secondary flash gas phase first separator (11) and the secondary flash gas phase second separator (12) to separate the liquid droplets entrained in the secondary flash gas, and the separated liquid phase returns to the secondary flash tank (6); A tertiary flash gas phase first separator (13) and a tertiary flash gas phase second separator (14), the tertiary flash gas sequentially enters the tertiary flash gas phase first separator (13) and the tertiary flash gas phase second separator (14) to separate the liquid droplets entrained in the tertiary flash gas.

3. The high-viscosity polymer solution devolatilization system according to claim 1, characterized in that, The top of the tertiary flash tank (8) is directly connected to the liquid-phase outlet of the secondary flash tank (6) and is arranged vertically up and down.

4. High-viscosity polymer solution devolatilization process, characterized in that, Operating in the system according to any one of claims 1-3, the process includes: (1) After the high-viscosity polymer solution enters the primary flash heater (1) for heating, it is dispersed by the primary flash tank distributor (2) at the top of the primary flash tank (3) and then falls into the primary flash tank (3) in a filamentous state for flashing to obtain a primary flash gas and a primary flash liquid; (2) After adding a devolatilization aid to the primary flash liquid, it enters the secondary flash heater (4) for heating. After being dispersed by the primary flash tank distributor (5) at the top of the secondary flash tank (6), it falls into the secondary flash tank (6) in a filamentous form for flashing, obtaining secondary flash gas and secondary flash liquid; (3) The top of the tertiary flash tank (8) is directly connected to the liquid phase outlet of the secondary flash tank (6). After the secondary flash liquid is dispersed by the tertiary flash tank distributor (7) at the top of the tertiary flash tank (8), it falls into the tertiary flash tank (8) in a filamentous form for flashing and devolatilization, obtaining tertiary flash gas and tertiary flash liquid; the tertiary flash liquid is the devolatilized high-viscosity polymer solution.

5. The high-viscosity polymer solution devolatilization process according to claim 4, characterized in that, The process further includes: The primary flash gas sequentially enters the first primary flash gas separator (9) and the second primary flash gas separator (10) from the gas phase outlet of the primary flash tank (3) to separate the liquid droplets entrained in the primary flash gas, and the separated liquid phase returns to the primary flash tank (3); The secondary flash gas sequentially enters the first secondary flash gas separator (11) and the second secondary flash gas separator (12) from the gas phase outlet of the secondary flash tank (6) to separate the liquid droplets entrained in the secondary flash gas, and the separated liquid phase returns to the secondary flash tank (6); The tertiary flash gas enters the tertiary flash gas separator (13) from the gas phase outlet of the tertiary flash tank (8) to separate the liquid droplets entrained in the tertiary flash gas.

6. The high-viscosity polymer solution devolatilization process according to claim 4, characterized in that, The operating pressure of the secondary flash tank (6) is lower than that of the primary flash tank (3).

7. The devolatilization process of the high-viscosity polymerization solution according to claim 4, characterized in that, The operating temperature of the primary flash heater (1) is 220°C to 233°C, and the operating pressure is 5.5 MPaG to 10.5 MPaG; the operating temperature of the primary flash tank (3) is 150°C to 180°C, and the operating pressure is 0.6 MPaG to 0.8 MPaG.

8. The high-viscosity polymer solution devolatilization process according to claim 4, characterized in that, The operating temperature of the secondary flash heater (4) is 210°C to 230°C, and the operating pressure is 1.4 MPaG to 2.2 MPaG; the operating temperature of the secondary flash tank (6) is 180°C to 206°C, and the operating pressure is 0.3 MPaG to 0.4 MPaG.

9. The high-viscosity polymer solution devolatilization process according to claim 4, characterized in that, The tertiary flash tank (8) operates under vacuum conditions, with an operating temperature of 220°C to 222°C and an operating pressure of 1 kPaA to 10 kPaA.

10. The high-viscosity polymer solution devolatilization process according to claim 4, characterized in that, The devolatilization aid is hexane.

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