A process system for preparing vinyl rubber-like copolymers

Abstract

The present invention provides a process system for preparing vinyl rubber-like copolymers. The process system of the present invention requires only one monomer separation tower, which is one less than some conventional process systems. This results in reduced steam consumption, reduced refrigeration consumption, fewer equipment units, and lower operational intensity. The technical solution provided by the present invention optimizes the production process, achieves a reasonable heat balance, and minimizes energy consumption.

Description

[0001] This application is a divisional application of the invention patent application with patent application number 202310275038.9, application date March 21, 2023, and invention name “A process system and process method for preparing vinyl rubber-like copolymers”. Technical Field

[0002] The invention relates to a process system and a process method for preparing vinyl rubber-like copolymers, belonging to the technical field of polymer preparation. Background Art

[0003] Solution olefin polymerization technology utilizes a Ziegler-Natta catalytic system, using C5-C8 linear alkanes as solvents and monomers such as ethylene, propylene, and butene to produce homopolymers or copolymers such as polyethylene, polypropylene, and polybutene. There are many types of ethylene rubber copolymers, the most important of which are EPDM and EPDM. The lack of double bonds in the main chain of EPDM rubber gives it high chemical stability and excellent weathering, heat, and aging resistance.

[0004] Polymerization is the most important process in producing ethylene rubber copolymers. In the polymerization unit, the comonomers ethylene, propylene, and a third comonomer are added to a polymerization reactor along with a solvent. The copolymerization reaction proceeds under the initiation of a catalyst. The monomers, catalyst, and resulting copolymer are all dissolved in the solvent.

[0005] The polymerization mechanism of ethylene-propylene-diene copolymers is anionic coordination polymerization, using a Ziegler-Natta catalyst. Each catalyst is dissolved in a solvent and undergoes a complexation reaction to form active centers. Ethylene and propylene then undergo a copolymerization reaction under the initiation of these centers to form a random copolymer. The key quality indicators of EPDM copolymers are controlled during the polymerization process, and molecular weight regulators are used to adjust the molecular weight of the copolymer.

[0006] Polymerization is an exothermic reaction, and the heat generated is carried away from the reaction system by the evaporation of the monomer and solvent. The heat generated during the polymerization process vaporizes some of the monomer and a small amount of solvent in the polymerization reactor. The gases are compressed and condensed outside the polymerization reactor before returning to the reactor. Temperature and pressure are important parameters to monitor during the polymerization process.

[0007] The polymer produced in the polymerization reactor is dissolved in the solvent hexane, known as the polymer solution. The polymer solution, which contains unreacted monomers, is fed into a degassing tower where it is heated to separate the unreacted monomers from the polymer solution. The unreacted monomers are compressed and condensed by a compressor before being returned to the polymerization reactor. The polymer, after monomer removal, is dissolved in the solvent and continuously fed out of the polymerization system. Summary of the Invention

[0008] The object of the present invention is to provide a new process system and process method for preparing vinyl rubber-like copolymers.

[0009] To achieve the above object, the present invention provides a process system for preparing an ethylene rubber-like copolymer, comprising:

[0010] Monomer input device, catalyst input device, solvent input device, reactor, monomer separation tower;

[0011] a first mixer, a second mixer, and a third mixer;

[0012] a first gas-liquid separation tank and a second gas-liquid separation tank;

[0013] a first cooler and a second cooler;

[0014] a first condenser, a second condenser, and a third condenser;

[0015] a first condensate receiving tank and a second condensate receiving tank;

[0016] a first heater and a second heater;

[0017] a first compressor and a second compressor;

[0018] Condensate pump, gel filter, tower bottom pump, reflux pump;

[0019] in,

[0020] The monomer input device is connected to the inlet of the first mixer, the catalyst input device is connected to the inlet of the third mixer, and the solvent input device is connected to the inlet of the first mixer, the inlet of the second mixer, and the inlet of the third mixer respectively;

[0021] The outlet of the first mixer is connected to the inlet of the first cooler, and the outlet of the first cooler is connected to the inlet of the reactor; the outlet of the second mixer and the outlet of the third mixer are respectively connected to the inlet of the reactor;

[0022] The top outlet of the reactor is connected to the inlet of the first condenser (for discharging monomer gas that does not participate in the reaction and a small amount of vaporized solvent), the outlet of the first condenser is connected to the inlet of the first gas-liquid separator, the liquid outlet of the first gas-liquid separator is connected to the inlet of the condensate pump, the outlet of the condensate pump is connected to the inlet of the first mixer, the gas outlet of the first gas-liquid separator is connected to the inlet of the first compressor, the outlet of the first compressor is connected to the inlet of the second condenser, the outlet of the second condenser is connected to the inlet of the first condensate receiving tank, the gas outlet of the first condensate receiving tank is connected to a pipe network outside the system, and the liquid outlet of the first condensate receiving tank is connected to the inlet of the first mixer (for inputting a mixture of propylene and SOL (solvent) into the first mixer);

[0023] The bottom outlet of the reactor is connected to the inlet of the middle part of the monomer separation tower, the top outlet of the monomer separation tower is connected to the inlet of the second cooler, the outlet of the second cooler is connected to the inlet of the second gas-liquid separation tank, the liquid outlet of the second gas-liquid separation tank is connected to the inlet of the reflux pump, the outlet of the reflux pump is connected to the inlet of the first mixer, the gas outlet of the second gas-liquid separation tank is connected to the pipeline outside the system and / or to the inlet of the second compressor, the outlet of the second compressor is connected to the inlet of the third condenser, the outlet of the third condenser is connected to the inlet of the second condensate receiving tank, the liquid outlet of the second condensate receiving tank is connected to the inlet of the first mixer, and the gas outlet of the second condensate receiving tank is connected to the pipeline outside the system and the inlet of the first mixer respectively;

[0024] The bottom outlet of the monomer separation column is connected to the inlet of the gel filter, the outlet of the gel filter is connected to the inlet of the bottom pump (preferably, the top of the filter and the bottom of the monomer separation column are at the same elevation, and the bottom of the filter is higher than the inlet of the bottom pump), the outlet of the bottom pump is connected to the inlet of the second heater, and the outlet of the second heater is connected to the bottom inlet of the monomer separation column;

[0025] The top outlet of the monomer separation tower is connected to the inlet of the second cooler, and the outlet of the second cooler is connected to the inlet of the second gas-liquid separation tank;

[0026] A first solvent input pipeline and a second solvent input pipeline are respectively provided at the top and bottom of the monomer separation tower, wherein a first heater is provided on the second solvent input pipeline; and a solvent inlet of the first heater is connected to a solvent input device.

[0027] In the above process system, each pipeline can be equipped with valves, flow meters, liquid level gauges, thermometers, pressure gauges, and other devices. In addition, some flow meters and liquid level gauges can be connected to the valves on the corresponding pipelines, and the flow meters and liquid level gauges can control the opening and closing of the valves, thereby controlling the flow rate and liquid level.

[0028] In the above process system, the reactor is used for carrying out the polymerization reaction and is provided with a corresponding flow meter. The reactor may be provided with a stirrer, and the specific method may be referred to in the prior art.

[0029] In the above process system, the first gas-liquid separation tank is used to achieve gas-liquid separation of the condensed product of the gas from the top of the reactor (condensed by the first condenser), wherein the gas leaves from the top outlet, returns to the reactor after compression and condensation, and the liquid leaves from the bottom and returns to the reactor.

[0030] In the above process system, the monomer separation tower is used to separate the reaction products of the polymerization reaction from the reactor, wherein the monomer is separated and discharged from the top, and returns to the reactor after gas-liquid separation (through the second gas-liquid separation tank), and the copolymer (i.e., the product of the polymerization reaction) enters the gel filter to remove the gel by filtration, and then is output through the bottom pump. Preferably, a solvent inlet is provided at the top of the monomer separation tower for injecting solvent when necessary. During the polymerization reaction, gel is the main component of the by-product. Gel is a cross-linked substance that is insoluble in solvents. If it remains in the copolymer, it will seriously affect the quality of the copolymer. In the process system of the present invention, the installation position of the gel filter is different from other processes, and the gel can be thoroughly removed. See the gel filtration process of a certain process. Figure 2 , Figure 2 The dot pattern in the figure represents the gel in the polymer solution. The gel is a soft small particle with a specific gravity less than that of the solution and floats on the top of the filter. After the gel filter 11 is installed in the tower bottom pump 12, the turbulence of the liquid in the gel filter 11 will increase. Under the action of the pressure difference, the soft gel particles will deform and be discharged from the outlet of the gel filter 11, which will seriously reduce the filtering effect. In the process system of the present invention, if Figure 3 As shown, the gel filter 11 is installed before the pump (bottom pump 12), and the polymer overflows into the gel filter 11. This filtration process allows most of the gel to accumulate in the gel filter 11, which can effectively improve the filtration effect.

[0031] In the above process system, the monomer input device preferably includes an H input line (hydrogen input line), an ETH input line (ethylene input line), a PRO input line (propylene input line), and an ENB input line (ethylidene norbornene input line). Each line can be equipped with a flow meter. This process system is suitable for the production of EPDM rubber, EPDM rubber, and the like. When using three or more monomers, the third and fourth monomers can enter the system through the ENB input line, or a separate line can be added for the fourth monomer. Molecular weight regulators can also be introduced through a separate line or through the ENB input line.

[0032] In the above process system, preferably, the catalyst input device includes a CAT input pipeline (main catalyst injection pipeline), an ETA input pipeline (activator input pipeline), and a CCD input pipeline (co-catalyst injection pipeline, CCD refers to the co-catalyst diluted with a solvent), and each pipeline can be provided with a flow meter.

[0033] In the above process system, the solvent input device includes a SOL input pipeline, which can be provided with a flow meter.

[0034] In the above process system, the first mixer is used to achieve mixing of monomers (H input pipeline, ETH input pipeline, PRO input pipeline, ENB input pipeline) and solvent (SOL input pipeline), the second mixer is used to achieve mixing of co-catalyst and solvent, and the third mixer is used to achieve mixing of main catalyst and solvent.

[0035] In the above process system, preferably, the process system further comprises a gas chromatograph connected to the connecting pipeline between the top outlet of the reactor and the inlet of the first condenser. More preferably, the gas chromatograph is further connected to the flowmeter on the H input pipeline, the flowmeter at the gas outlet of the first condensate receiving tank, and the connecting pipeline between the top outlet of the reactor and the inlet of the first condenser. The output of the gas chromatograph controls the flow rate of the H input pipeline, the flow rate outflowing from the top of the reactor (the flow rate entering the first condenser), and the flow rate of the gas phase outlet of the first condensate receiving tank, and these three flow rates are changed simultaneously according to the measured values ​​of the gas chromatograph.

[0036] In the above-mentioned process system, preferably, the process system also includes a reactor top discharge gas phase flow meter FI, which is connected to the flow meter on the ETH input pipeline, the connecting pipeline between the top outlet of the reactor and the inlet of the first condenser, the flow meter on the CAT input pipeline, and the flow meter on the ETA input pipeline. The reactor top discharge gas phase flow meter FI is connected to each flow regulating valve through an instrument signal line, and the output signal of the reactor top discharge gas phase flow meter FI is sent to each flow regulating valve. The measured value of the reactor top discharge gas phase flow meter FI also has an impact on the H input pipeline flow, the flow (flow entering the first condenser) flowing out of the top of the reactor, the flow of the gas phase outlet of the first condensate receiving tank, and other flows entering the reactor. The reactor top discharge gas phase flow meter FI is not connected between the chromatograph.

[0037] In the above process system, preferably, each of the first cooler, the second cooler, the first condenser, the second condenser, and the third condenser is provided with a cooling water channel. Furthermore, a thermometer may be provided on the outlet pipes of the coolers and condensers to detect the temperature and connect to the valve on the cooling water channel to adjust the cooling water flow rate according to the temperature of the process material, thereby maintaining a stable process material temperature. For specific configurations, reference may be made to conventional coolers and condensers.

[0038] In the above process system, preferably, the first compressor and the second compressor are both reciprocating compressors.

[0039] In the above process system, preferably, the second condensate receiving tank is provided with a liquid level gauge for monitoring the liquid level in the second condensate receiving tank.

[0040] In the above process system, preferably, the outlet of the tower bottom pump is connected not only to the inlet of the second heater but also to equipment outside the process system for delivering the glue solution to subsequent units. The tower bottom pump is used to deliver the glue solution to the second heater for heating and then returns it to the monomer separation tower. When the glue solution (copolymer product) in the tower bottom pump meets the requirements, it can be delivered to the subsequent units. The circulation of the glue solution between the second heater and the monomer separation tower and its delivery to the subsequent units are carried out simultaneously and continuously.

[0041] In the above-mentioned process system, preferably, the top outlet of the second gas-liquid separation tank is also connected to the external flare pipe network, and a valve is provided on the connecting pipeline. The valve is connected to the flow meter provided at the front end of the second compressor and is controlled by the flow meter. The gas flow rate discharged to the outside of the system is set according to the produced brand, production load and changes in gas composition.

[0042] In the above process system, preferably, a portion of the gas in the second condensate receiving tank is discharged into the flare network through flow control, and the remaining portion is returned to the reactor through pressure control. The liquid in the second condensate receiving tank is returned to the reactor under pressure through liquid level control.

[0043] The present invention also provides a process for preparing an ethylene rubber-like copolymer, which is carried out using the above process system, and the process comprises:

[0044] Allowing monomers, catalysts, and solvents to undergo polymerization reaction in a reactor, wherein the catalyst includes a main catalyst, a co-catalyst, and an activator;

[0045] Control the reactor's temperature, pressure, liquid level, and reactor exhaust gas flow rate; utilize the polymerization heat to evaporate a portion of the monomer and solvent from the reactor, condense them, and return them to the reactor, thereby removing the reaction heat from the reactor;

[0046] The polymer obtained by the reaction enters the monomer separation tower, and the unreacted monomer is evaporated, and the evaporated monomer is returned to the reactor to participate in the reaction.

[0047] The process provided by the present invention can employ a solution polymerization process, using a linear alkane as the solvent and two or three olefins as the primary polymerizable reactants. The main equipment comprises a polymerization reactor with an agitator, a monomer separation tower, and two reciprocating compressors. Various raw materials and catalysts are metered into the reactor, where the reactants, catalyst, and product are dissolved in the solvent. The product is separated into a gel by a gel filter and then fed to subsequent stages. Unreacted monomer is pressurized by a compressor and then recycled back to the reactor to continue the polymerization reaction. The polymerization reaction is exothermic, and the reaction heat is removed from the reactor by evaporating the monomer and solvent, condensing outside the reactor, and then returning to the reactor.

[0048] In the above process, preferably, the monomers include one or a combination of two or more of ethylene, propylene and dienes. The process may also use a third monomer and a fourth monomer, which may be ENB and dicyclopentadiene, respectively.

[0049] In the above process, preferably, the solvent comprises a C5-C8 straight-chain alkane.

[0050] In the above process, the main catalyst can be prepared according to the desired reaction. Preferably, the catalyst is a complex formed by a titanium\vanadium compound (titanium or vanadium compound) and an alkyl aluminum soluble in a hydrocarbon solvent.

[0051] In the above process, preferably, the mass ratio of the titanium / vanadium compound to the alkyl aluminum is 5-15:1.

[0052] In the above process, preferably, the titanium / vanadium compound includes titanium tetrachloride and / or vanadium oxychloride.

[0053] In the above process, preferably, the alkyl aluminum includes one or a combination of two or more of triisobutyl aluminum, triethyl aluminum, diethyl aluminum monochloride, ethyl aluminum dichloride, and ethyl aluminum sesquichloride.

[0054] In the above process method, preferably, the main catalyst contains alcohols and / or esters; the selectivity of the catalyst can be changed by adding alcohols or esters; more preferably, the alcohols include one or a combination of two or more of methanol, ethanol, and propanol; and the esters include ethyl trichloroacetate.

[0055] In the above process method, preferably, the amount of the alcohol substance and / or ester substance is: the molar ratio of the alcohol substance to the titanium / vanadium compound is 1:1; the mass ratio of the ester substance to the titanium / vanadium compound is in the range of 5 to 15.

[0056] In the above process, preferably, the catalyst (i.e., main catalyst) is selected from one of the following six categories:

[0057]

[0058] Among them, A represents titanium and vanadium;

[0059] AX represents titanium, vanadium, and alcohols;

[0060] BX stands for ethylaluminum dichloride;

[0061] BM stands for diethylaluminum monochloride;

[0062] BQ stands for ethylaluminum sesquichloride;

[0063] ES stands for ester compound.

[0064] Among the reaction systems corresponding to the six catalyst types mentioned above, the first type produces compounds with higher Mooney viscosities, the second, fourth, and sixth types produce copolymers with narrow molecular weight distributions, and the third and fifth types produce copolymers with broad molecular weight distributions. Products with broad molecular weight distributions are primarily used in plastic modification. Products with narrow molecular weight distributions have better oil solubility and are suitable as oil additives.

[0065] In the above process, preferably, the activator (ETA) is an ester compound, the main function of which is to increase the activity of the main catalyst.

[0066] In the above process, preferably, the co-catalyst is a metallic aluminum compound, such as an alkyl aluminum catalyst.

[0067] In the above process, preferably, the efficiency of the main catalyst is 1600-3800 g polymer / g catalyst.

[0068] In the above process, the apparatus is first started up and reaches a stable operating state. Preferably, the critical control point operating parameters are as follows: the temperature in the reactor is controlled at 30-80°C (more preferably 40-60°C), the pressure is controlled at 0.5-3.0 MPa (preferably 0.6-1.5 MPa), and the solvent flow rate into the reactor is controlled at 30-50 t / h. The mass flow rates of the various monomer components can be adjusted according to the values ​​required by the product formulation.

[0069] In the above process, the main factors affecting the performance of the copolymer include polymerization reaction temperature, catalytic activity (i.e., catalyst efficiency), comonomer concentration ratio, molecular weight regulator to comonomer concentration ratio, polymerization reaction residence time, etc. These parameters can be obtained through actual processes.

[0070] Determination of polymerization reaction temperature:

[0071] The polymerization temperature has a great influence on the polymerization reaction rate, molecular weight distribution, and catalyst efficiency. Determining the appropriate reaction temperature has an important influence on the properties of the generated copolymer. The relationship between polymerization temperature and catalyst activity can be found in Figure 4 :

[0072] Figure 4 The catalyst activity versus temperature curve shown indicates that catalyst activity is inversely proportional to the polymerization reaction temperature. Furthermore, increasing temperature significantly reduces the solubility of the monomer in the solvent, and the lifetime of the active sites decreases with increasing temperature. As temperature increases, catalyst efficiency decreases, leading to a decrease in yield, and polymer molecular weight decreases with increasing temperature. In the above process, the polymerization reaction temperature is preferably controlled between 30°C and 80°C, more preferably between 40°C and 60°C.

[0073] Determination of comonomer ratio in polymerization reaction system:

[0074] Due to the difference in reactivity ratio, the comonomer ratio in the polymerization reaction system directly affects the amount of each monomer in the copolymer. The change in the concentration of each monomer also has a significant effect on the polymerization reaction rate. Among them, the corresponding relationship between the amount of each monomer in the product and the gas phase composition in the reaction system is as follows: Figure 5 The corresponding relationship between the molar ratio of ethylene to propylene in the reactor gas phase and the ethylene content in the product is shown in Table 1.

[0075] Table 1

[0076]

[0077]

[0078] Effect of catalyst concentration:

[0079] The relationship curve between catalyst concentration, catalyst efficiency and monomer single-pass conversion rate in the polymerization reaction system is as follows: Figure 6 shown.

[0080] Increasing catalyst concentration increases the number of active centers and accelerates the polymerization reaction, but catalyst efficiency decreases, polymer molecular weight decreases, and Mooney viscosity decreases accordingly. Due to the accelerated reaction rate, the polymerization temperature will also increase significantly. The mass ratio of the aluminum alkyl to the vanadium catalyst also has a crucial impact on the polymerization reaction. In addition to acting as a co-catalyst to alkylate the vanadium metal to form active centers, the aluminum alkyl catalyst also plays a role in chain transfer and purifies trace impurities in the reaction system. When the mass ratio of the aluminum to vanadium catalyst in the reaction system is greater than 20, the polymerization rate decreases. When the mass ratio of the aluminum to vanadium catalyst in the reaction system is less than 5, a large amount of gel formation occurs. The single-pass conversion rate of the monomer increases with increasing catalyst concentration. In the polymerization catalyst formulation design, the present invention specifies a mass ratio of aluminum to vanadium catalyst of 7; the concentration of vanadium in the solution ranges from 1:200,000 to 400,000 (by weight).

[0081] In the above process, preferably, the process also includes the step of adding a molecular weight regulator. Molecular weight regulators act as chain terminators during polymerization reactions, regulating the molecular weight of the polymer. The process of the present invention controls molecular weight by adjusting the concentration ratio of the molecular weight regulator to the comonomer. Different product grades correspond to different ratios, and a 0.1 change in this ratio results in a 3-unit change in the Mooney viscosity of the product. More preferably, the mass ratio of the molecular weight regulator to the monomer in the reactor gas phase is 0.1-1.

[0082] In the above-mentioned process, the determination of the polymerization reaction residence time is closely related to the polymerization reaction speed and the life of the catalyst. Within a few minutes after the reaction starts, the molecular weight reaches a relatively high value. After this, as the high molecular weight fraction increases, the molecular weight of the multipolymer increases, but its amplitude is greatly reduced. Polymer yield rises with the increase of the residence time, and molecular weight and catalyst efficiency also improve slightly, but the conversion rate of the monomer will decline therewith with the utilization rate of the reactor. Preferably, the residence time of the polymerization reaction is 20 minutes to 120 minutes.

[0083] In the above process, the concentration of the product in the reactor liquid phase affects the yield, the heat and mass transfer processes of the polymerization reaction, the subsequent solvent recovery costs, and the subsequent catalyst residue removal. Preferably, during the polymerization reaction, the concentration of the resulting copolymer in the reactor is controlled to be 5-18 wt%.

[0084] In the above process, the flow rate of the circulating gas in the reactor is determined according to the gas production of the polymerization reaction and the stirring intensity requirement of the liquid phase in the reactor. Preferably, during the polymerization reaction, the flow rate of the circulating gas in the reactor is controlled to be 1000-3000m 3 / h.

[0085] In the above process, preferably, the quality specifications of the product of the polymerization reaction (i.e., copolymer) include:

[0086] The products of polymer reactions (including binary, ternary, tetramer EPDM and oil-extended EPDM, etc.) must meet the following requirements:

[0087] Molecular weight distribution: Mw / Mn=1.2-4.8;

[0088] Combined propylene mass fraction: 25-52wt%;

[0089] Mooney viscosity: ML1+4100=25-120.

[0090] The technical solution provided by the present invention optimizes the production process, achieves a reasonable heat balance, and minimizes energy consumption. The process system of the present invention requires only one set of monomer separation towers, one less than some conventional process systems. This results in reduced steam consumption, reduced cooling consumption, fewer equipment units, and lower operational intensity.

[0091] The present invention is a solution olefin polymerization technology, and its preferred technical solution can be a complete set of production process flow, complete operating parameters, complete copolymerization monomers and catalysts and various additives, complete automatic control scheme, and efficient process control.

[0092] The process system and process method provided by the present invention have wide applicability and can produce 44 typical brands of ethylene rubber copolymers. BRIEF DESCRIPTION OF THE DRAWINGS

[0093] Figure 1 This is a schematic structural diagram of the process system for preparing vinyl rubber-like copolymers provided in Example 1.

[0094] Figure 2 This is a schematic diagram of the installation method of the gel filter in the existing process system.

[0095] Figure 3 Schematic diagram of the installation method of the gel filter in the present invention.

[0096] Figure 4 This is the relationship curve between catalyst activity and polymerization reaction temperature.

[0097] Figure 5 This is a graph showing the corresponding relationship between the binding amount of each monomer in the product and the gas phase composition in the reaction system.

[0098] Figure 6 It is the relationship curve between the catalyst concentration, catalyst efficiency and monomer single-pass conversion rate in the polymerization reaction system.

[0099] Description of main figures:

[0100] Reactor 1, monomer separation tower 2;

[0101] A first mixer 31, a second mixer 32, and a third mixer 33;

[0102] A first gas-liquid separation tank 41 and a second gas-liquid separation tank 42;

[0103] A first cooler 51 and a second cooler 52;

[0104] A first condenser 61, a second condenser 62, and a third condenser 63;

[0105] A first condensate receiving tank 71 and a second condensate receiving tank 72;

[0106] A first heater 81 and a second heater 82;

[0107] A first compressor 91 and a second compressor 92;

[0108] Condensate pump 10, gel filter 11, bottom pump 12, reflux pump 13;

[0109] Liquid level meter LC, pressure gauge PC, flow meter FC, thermometer TC, and gas phase flow meter FI discharged from the top of the reactor. DETAILED DESCRIPTION

[0110] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0111] Example 1

[0112] This embodiment provides a process system for preparing vinyl rubber copolymer, the structure of which is as follows: Figure 1 As shown. The process system includes:

[0113] Single input device: including H input pipeline, ETH input pipeline, PRO input pipeline, and ENB input pipeline, each pipeline is equipped with a flow meter FC;

[0114] Catalyst input device: including CAT input pipeline, ETA input pipeline, CCD input pipeline, each pipeline is equipped with a flow meter FC;

[0115] Solvent input device: including SOL input pipeline, which is equipped with flow meter FC;

[0116] Reactor 1: equipped with corresponding liquid level gauge LC and pressure gauge PC, and equipped with a stirrer;

[0117] Monomer separation tower 2: equipped with liquid level gauge LC;

[0118] Gas chromatograph: connected to the connecting pipeline between the top outlet of the reactor 1 and the inlet of the first condenser 61, and also connected to the flow meter FC on the H input pipeline and the flow meter FC at the gas outlet of the first condensate receiving tank 71;

[0119] Reactor top discharge gas phase flow meter FI: connected to the flowmeter FC on the ETH input pipeline, the flowmeter FC on the PRO input pipeline, the flowmeter FC on the ENB input pipeline, the connecting pipeline between the top outlet of the reactor 1 and the inlet of the first condenser 61, the flowmeter FC on the CAT input pipeline, the flowmeter FC on the ETA input pipeline, the flowmeter FC on the CCD input pipeline, and the flowmeter FC on the SOL input pipeline;

[0120] A first mixer 31, a second mixer 32, and a third mixer 33;

[0121] The first gas-liquid separation tank 41 and the second gas-liquid separation tank 42 are respectively provided with a liquid level gauge LC;

[0122] The first cooler 51 and the second cooler 52 are each provided with a cooling water channel. A thermometer TC is provided on the outlet pipe of the first cooler 51 to detect the temperature and is connected to a valve on the cooling water channel to control the flow of cooling water.

[0123] First condenser 61, second condenser 62, and third condenser 63: Each of the first condenser 61 and the third condenser 63 is provided with a cooling water channel. Furthermore, a thermometer TC is provided on the outlet pipe of the first condenser 61. The thermometer TC is used to detect the temperature and is connected to a valve on the cooling water channel to control the flow of cooling water.

[0124] The first condensate receiving tank 71 and the second condensate receiving tank 72 are each provided with a liquid level gauge LC;

[0125] A first heater 81 and a second heater 82;

[0126] The first compressor 91 and the second compressor 92 are both reciprocating compressors;

[0127] Condensate pump 10, gel filter 11, bottom pump 12, reflux pump 13;

[0128] in,

[0129] The monomer input device is connected to the inlet of the first mixer 31, the catalyst input device is connected to the inlet of the third mixer 33, and the solvent input device is connected to the inlet of the first mixer 31, the inlet of the second mixer 32, and the inlet of the third mixer 33 respectively;

[0130] The outlet of the first mixer 31 is connected to the inlet of the first cooler 51, and the outlet of the first cooler 51 is connected to the inlet of the reactor 1; the outlet of the second mixer 32 and the outlet of the third mixer 33 are connected to the inlet of the reactor 1, and the two are merged into one pipeline and then connected to the inlet of the reactor 1;

[0131] The top outlet of the reactor 1 is connected to the inlet of the first condenser 61, the outlet of the first condenser 61 is connected to the inlet of the first gas-liquid separation tank 41, the liquid outlet of the first gas-liquid separation tank 41 is connected to the inlet of the condensate pump 10 (a valve is provided on the connecting pipeline, and the valve is connected to the liquid level gauge LC of the first gas-liquid separation tank 41 to realize the liquid level control in the first gas-liquid separation tank), the outlet of the condensate pump 10 is connected to the inlet of the first mixer 31, and the gas outlet of the first gas-liquid separation tank 41 is connected to the inlet of the first compressor 91 (the connection between the two A valve is provided on the pipe connection, which is controlled by the pressure gauge PC of the reactor 1); the outlet of the first compressor 91 is connected to the inlet of the second condenser 62, the outlet of the second condenser 62 is connected to the inlet of the first condensate receiving tank 71, the gas outlet of the first condensate receiving tank 71 is respectively connected to the pipe network outside the system and the inlet of the first mixer 31, and the liquid outlet of the first condensate receiving tank 71 is connected to the inlet of the first mixer 31 (a valve is provided on the connecting pipe between the two, which is controlled by the liquid level gauge LC of the first condensate receiving tank 71);

[0132] The bottom outlet of the reactor 1 is connected to the inlet of the middle part of the monomer separation tower 2, the top outlet of the monomer separation tower 2 is connected to the inlet of the second cooler 52, the outlet of the second cooler 52 is connected to the inlet of the second gas-liquid separation tank 42, the liquid outlet of the second gas-liquid separation tank 42 is connected to the inlet of the reflux pump 13 (a valve is provided on the connecting pipeline of the two, and the valve is controlled by the liquid level meter LC of the second gas-liquid separation tank 42), the outlet of the reflux pump 13 is connected to the inlet of the first mixer 31, and the gas outlet of the second gas-liquid separation tank 42 is connected to the pipe network outside the system and / or is connected to the inlet of the second compressor 92 (the top outlet of the second gas-liquid separation tank 42 A valve is provided on a connecting pipeline between the outlet and the external pipe network, and the valve is connected to the pressure gauge PC arranged at the front end of the second compressor 92, and is controlled by the pressure gauge PC), the outlet of the second compressor 92 is connected to the inlet of the third condenser 63, the outlet of the third condenser 63 is connected to the inlet of the second condensate receiving tank 72, the liquid outlet of the second condensate receiving tank 72 is connected to the inlet of the first mixer 31 (a valve is provided on the connecting pipeline of the two, and the valve is controlled by the liquid level gauge LC of the second condensate receiving tank 72), and the gas outlet of the second condensate receiving tank 72 is connected to the flare pipe network outside the system and the inlet of the first mixer 31 respectively;

[0133] The bottom outlet of the monomer separation tower 2 is connected to the inlet of the gel filter 11, the outlet of the gel filter 11 is connected to the inlet of the tower bottom pump 12, the outlet of the tower bottom pump 12 is connected to the inlet of the second heater 82 and is also connected to equipment outside the process system (a valve is provided on the connecting pipeline between the two, and the valve is controlled by the liquid level gauge of the monomer separation tower 2 to control the delivery of glue to equipment outside the system). The outlet of the second heater 82 is connected to the bottom inlet of the monomer separation tower 2; the top outlet of the monomer separation tower 2 is connected to the inlet of the second cooler 52, and the outlet of the second cooler 52 is connected to the inlet of the second gas-liquid separation tank 42;

[0134] A first solvent input pipeline and a second solvent input pipeline are respectively provided at the top and bottom of the monomer separation tower 2, wherein the first solvent input pipeline is provided with a flow meter FC, and the second solvent input pipeline is provided with a first heater 81; the solvent inlet of the first heater 81 is connected to the SOL input pipeline, and a flow meter is provided on the connecting pipeline between the two;

[0135] The first heater 81 and the second heater 82 are each provided with a steam input pipeline for providing heat. A valve is provided on the steam input pipeline of the first heater 81, and the valve is controlled by a thermometer TC at the outlet of the first heater 81. A valve is provided on the steam input pipeline of the second heater 82, and the valve is controlled by a thermometer TC at the outlet of the second heater 82.

[0136] The pipeline connected to the flare pipe network outside the system is communicated with the pipeline entering the bottom of the reactor 1.

[0137] Example 2

[0138] This embodiment provides a process for preparing a vinyl rubber copolymer, which is carried out using the system of Example 1 and specifically includes the following steps:

[0139] The first stream formed by mixing the comonomer, catalyst, solvent, etc. enters the reactor 1 for reaction;

[0140] The monomer gas that does not participate in the reaction and a small amount of vaporized solvent discharged from the top outlet of the reactor 1 enter the first condenser 61 and the first gas-liquid separation tank 41 in sequence for gas-liquid separation;

[0141] The gas separated by the first gas-liquid separation tank 41 is pressurized by the first compressor 91 to form the 04th stream, enter the second condenser 62, and then enter the first condensate receiving tank 71. The liquid in the first condensate receiving tank 71 is merged into the 011th stream as the 06th stream, and the gas in the first condensate receiving tank 71 is used as the 05th stream to enter the external flare pipe network.

[0142] The liquid separated from the first gas-liquid separation tank 41 is mixed with the No. 06 stream from the first condensate receiving tank 71, the stream from the reflux pump 13, and the stream from the second condensate receiving tank 72 through the condensate pump 10 to form the No. 011 stream; the No. 011 stream and the supplemented solvent are mixed in the first mixer 31 to form the No. 02 stream and enter the reactor 1 to participate in the reaction;

[0143] The third stream discharged from the bottom outlet of reactor 1 enters monomer separation tower 2 for separation of unreacted monomers. The heaters at the bottom of the tower are used to heat the medium entering the tower. The bottom pump 12 has two functions: first, to deliver the glue solution to subsequent processing sections, and second, to force the higher-viscosity glue solution to circulate through the heater before entering monomer separation tower 2. The glue solution is transported by bottom pump 12 to the second heater 82 for heating, and then returned to monomer separation tower 2. When the glue solution (copolymer product) from bottom pump 12 meets the requirements, it can be delivered as the eighth stream to the subsequent units. The glue solution from bottom pump 12 circulates continuously between the second heater 82 and monomer separation tower 2 and is delivered to the subsequent units simultaneously.

[0144] The gas No. 07 logistics from the top of the monomer separation tower 2 enters the second cooler 52 for cooling, and then enters the second gas-liquid separation tank 42 for separation. The liquid part obtained from the second gas-liquid separation tank 42 is merged into the No. 011 logistics through the reflux pump 13. The gas product obtained from the second gas-liquid separation tank 42 enters the second compressor 92 for pressurization to form the No. 09 logistics, and then enters the second condensate receiving tank 72 after condensation through the second condenser 62. The gas product separated from the second gas-liquid separation tank 42 can also directly enter the second condensate receiving tank 72.

[0145] Part of the gas in the second condensate receiving tank 72 is discharged into the flare network through logistics 010 under flow control, and the other part is returned to reactor 1 under pressure control; the liquid in the second condensate receiving tank 72 is returned to reactor 1 through logistics 011 under liquid level control under pressure. Specific process logistics data are shown in Table 2:

[0146] Table 2 Process logistics data of Example 2

[0147]

[0148]

[0149] Note: Comonomer 1 is ethylene; Comonomer 2 is propylene; Comonomer 3 is ENB; Comonomer 4 is dicyclopentadiene.

[0150] The product specifications of the polymerization reaction are as follows:

[0151] Molecular weight distribution: Mw / Mn=1.5-4;

[0152] Combined propylene mass fraction: 28-45wt%;

[0153] Mooney viscosity: ML1+4100=30-125.

Claims

1. A process system for preparing an ethylene-based rubber copolymer, comprising: A monomer input device, a catalyst input device, a solvent input device, a reactor (1), and a monomer separation tower (2); a first mixer (31), a second mixer (32), and a third mixer (33); a first gas-liquid separation tank (41) and a second gas-liquid separation tank (42); A first cooler (51), a second cooler (52); a first condenser (61), a second condenser (62), and a third condenser (63); a first condensate receiving tank (71) and a second condensate receiving tank (72); a first heater (81), a second heater (82); a first compressor (91), a second compressor (92); Condensate pump (10), gel filter (11), bottom pump (12), reflux pump (13); in, The monomer input device is connected to the inlet of the first mixer (31), the catalyst input device is connected to the inlet of the third mixer (33), and the solvent input device is connected to the inlet of the first mixer (31), the inlet of the second mixer (32), and the inlet of the third mixer (33) respectively; The outlet of the first mixer (31) is connected to the inlet of the first cooler (51), and the outlet of the first cooler (51) is connected to the inlet of the reactor (1); the outlet of the second mixer (32) and the outlet of the third mixer (33) are respectively connected to the inlet of the reactor (1); The top outlet of the reactor (1) is connected to the inlet of the first condenser (61), the outlet of the first condenser (61) is connected to the inlet of the first gas-liquid separation tank (41), the liquid outlet of the first gas-liquid separation tank (41) is connected to the inlet of the condensate pump (10), the outlet of the condensate pump (10) is connected to the inlet of the first mixer (31), the gas outlet of the first gas-liquid separation tank (41) is connected to the inlet of the first compressor (91), the outlet of the first compressor (91) is connected to the inlet of the second condenser (62), the outlet of the second condenser (62) is connected to the inlet of the first condensate receiving tank (71), the gas outlet of the first condensate receiving tank (71) is connected to the pipe network outside the system, and the liquid outlet of the first condensate receiving tank (71) is connected to the inlet of the first mixer (31); The bottom outlet of the reactor (1) is connected to the inlet of the middle part of the monomer separation tower (2), the top outlet of the monomer separation tower (2) is connected to the inlet of the second cooler (52), the outlet of the second cooler (52) is connected to the inlet of the second gas-liquid separation tank (42), the liquid outlet of the second gas-liquid separation tank (42) is connected to the inlet of the reflux pump (13), the outlet of the reflux pump (13) is connected to the inlet of the first mixer (31), the gas outlet of the second gas-liquid separation tank (42) is connected to the pipe network outside the system and / or to the inlet of the second compressor (92), the outlet of the second compressor (92) is connected to the inlet of the third condenser (63), the outlet of the third condenser (63) is connected to the inlet of the second condensate receiving tank (72), the liquid outlet of the second condensate receiving tank (72) is connected to the inlet of the first mixer (31), and the gas outlet of the second condensate receiving tank (72) is connected to the pipe network outside the system and the inlet of the first mixer (31) respectively; The bottom outlet of the monomer separation tower (2) is connected to the inlet of the gel filter (11), the outlet of the gel filter (11) is connected to the inlet of the bottom pump (12), the outlet of the bottom pump (12) is connected to the inlet of the second heater (82), and the outlet of the second heater (82) is connected to the bottom inlet of the monomer separation tower (2); The top outlet of the monomer separation tower (2) is connected to the inlet of the second cooler (52), and the outlet of the second cooler (52) is connected to the inlet of the second gas-liquid separation tank (42); A first solvent input pipeline and a second solvent input pipeline are respectively provided at the top and bottom of the monomer separation tower (2), wherein a first heater (81) is provided on the second solvent input pipeline; and a solvent inlet of the first heater (81) is connected to a solvent input device.

2. The process system according to claim 1, wherein: The monomer input device includes a hydrogen input pipeline, an ethylene input pipeline, a propylene input pipeline, and an ethylidene norbornene input pipeline.

3. The process system according to claim 2, wherein: The catalyst input device includes a main catalyst input pipeline and an activator input pipeline.

4. The process system according to claim 3, wherein: The process system also includes a gas chromatograph, which is connected to the connecting pipeline between the top outlet of the reactor (1) and the inlet of the first condenser (61); the gas chromatograph is also connected to the flow meter on the hydrogen input pipeline, the flow meter at the gas outlet of the first condensate receiving tank (71), and the connecting pipeline between the top outlet of the reactor (1) and the inlet of the first condenser (61).

5. The process system according to claim 3, wherein: The process system also includes a gas phase flow meter discharged from the top of the reactor, which is connected to the flow meter on the ethylene input pipeline, the connecting pipeline between the top outlet of the reactor (1) and the inlet of the first condenser (61), the flow meter on the main catalyst input pipeline, and the flow meter on the activator input pipeline.

6. The process system according to claim 1, wherein: The solvent input device includes a solvent input pipeline.

7. The process system according to claim 1, wherein: The first cooler (51), the second cooler (52), the first condenser (61), the second condenser (62), and the third condenser (63) are respectively provided with cooling water channels.

8. The process system according to claim 1, wherein: The first compressor (91) and the second compressor (92) are both reciprocating compressors.

9. The process system according to claim 1, wherein: The outlet of the tower bottom pump (12) is connected to equipment outside the process system and is used to send the glue solution to subsequent units.

10. The process system according to claim 1, wherein: The top outlet of the second gas-liquid separation tank (42) is also connected to an external flare pipe network, and a valve is provided on the connecting pipe, which is connected to a flow meter provided at the front end of the second compressor (92).

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