Method and device for controlling the polymerization process in the production of butadiene rubber

Abstract

The present application relates to the technical field of cis-butadiene rubber production, and is a control method and device for a polymerization reaction process in cis-butadiene rubber production. The control method for the polymerization reaction process in cis-butadiene rubber production first controls a feeding stage and an initiation stage to make the polymerization reaction reach a stable state of normal polymerization reaction. Then, when the mass of raw materials or the mass of catalyst fluctuates, the control method maintains the polymerization reaction temperature of the first reactor in the polymerization stage to make the polymerization reaction run smoothly. Finally, when the water content of raw materials fluctuates, the control method sets a proportional relationship between the change amount of the water content of raw materials and the adjustment of the aluminum agent formula, adjusts the aluminum agent formula in advance, and controls the polymerization reaction to be stable. Through the control method for the polymerization reaction process in cis-butadiene rubber production, the Mooney (ML(1+4) 100 DEG C) of the obtained cis-butadiene rubber is in the range of 41 to 49, and the Mooney is qualified.

Description

Technical Field

[0001] This invention relates to the field of butadiene rubber production technology, and is a method and apparatus for controlling the polymerization reaction process in butadiene rubber production. Background Technology

[0002] Butadiene rubber (BR) is a structurally regular synthetic rubber polymerized from butadiene monomers. Depending on the catalyst used, it includes nickel-based BR and rare-earth (neodymium-based) BR. Process control is crucial during BR polymerization. Excessive catalyst formulation and butadiene concentration can cause a series of problems. First, in the initial polymerization reactor, the butadiene monomer will polymerize too rapidly, resulting in insufficient dispersion and dissipation of polymerization heat, making the system prone to explosive polymerization. Second, the excessively rapid polymerization rate leads to large fluctuations in the Mooney viscosity of the BR product and issues with substandard quality.

[0003] The existing technology, such as the Chinese patent document CN107522806B, discloses a continuous polymerization method for preparing rare earth cis-butadiene rubber. This method is specifically used for the continuous polymerization of rare earth cis-butadiene rubber with a narrow molecular weight distribution and high Mooney molecular weight distribution. The catalyst used in this method consists of five substances: rare earth phosphate compound, diene, hydrogenated alkyl aluminum, organochloride, and alkyl aluminum. The catalyst is aged continuously by adding the five substances in a certain order and with a specific residence time. The aged catalyst is then continuously fed into the polymerization reactor for continuous butadiene polymerization. In the process of rare earth cis-butadiene rubber synthesis, rare earth cis-butadiene rubber with a Meney value of 55-100, a number-average molecular weight ≥180,000, and a molecular weight distribution of 1.3-2.5 is directly synthesized. The vulcanized rubber of the product has excellent performance and processing application properties. However, this patent does not cover the process control in the polymerization production.

[0004] Chinese patent document CN117327218A discloses a method for polymerizing nickel-based cis-butadiene and its application. This invention relates to the field of butadiene polymerization processes and discloses a method for polymerizing nickel-based cis-butadiene and its application. The method involves continuously introducing a rare earth catalyst and a Mooney viscosity modifier into the polymerization reaction system under solution polymerization conditions. The feed flow rate N of the rare earth catalyst is adjusted according to the measured amount of unreacted monomer in the reactor, and the feed flow rate A of the Mooney viscosity modifier is adjusted according to the measured Mooney viscosity of the polymer product. The feed flow rate N of the rare earth catalyst is reset every time interval tN, where tN is 0.2-2 times the reaction residence time. The feed flow rate A of the Mooney viscosity modifier is reset every time interval tA, where tA is 0.2-0.5 times the reaction residence time. According to the method of this invention, the monomer conversion rate and the Mooney viscosity of the cis-butadiene rubber product can be precisely controlled, improving production efficiency and enhancing product quality stability. While this patent relates to a polymerization method for nickel-based butadiene rubber, its control methods differ. This patent focuses on precisely controlling Mooney viscosity. It monitors the Mooney viscosity of the polymerization product in real time and dynamically adjusts the feed flow rates of the rare earth catalyst and Mooney viscosity modifier according to a preset formula, thereby controlling the Mooney viscosity within ±5% of the set value. The core of this method lies in feedback control, which makes real-time adjustments based on the quality indicators of the final product to ensure product consistency and stability.

[0005] Chinese patent document CN109694422B discloses an automatic control method for the polymerization of chloroprene rubber. This method includes steps such as polymerization initiation, feeding, polymerization, sampling and testing, and polymerization termination. Using this method, the problem of large inherent quality fluctuations in existing products can be solved. This patent focuses on the automatic control of the polymerization process. It controls each step of the polymerization process through a DCS system, including polymerization initiation, emulsion feeding, polymerization, sampling and testing, and polymerization termination, thereby automating the polymerization process, reducing manual operation, and improving production efficiency and product quality stability. This patent only addresses the automatic control of the chloroprene rubber polymerization process and does not cover the control of the initiation process.

[0006] Therefore, there is an urgent need to find a new method for controlling the polymerization reaction process in the production of butadiene rubber, so as to effectively solve the problems of uncontrolled polymerization during the feeding and start-up process, the risk of explosive polymerization, and the production of butadiene rubber with substandard Mooney quality in the existing butadiene rubber polymerization production. Summary of the Invention

[0007] This invention provides a method and apparatus for controlling the polymerization reaction process in the production of butadiene rubber, overcoming the shortcomings of the prior art. It can effectively solve the problems of uncontrolled polymerization during the feeding and start-up process, the risk of explosive polymerization, and the production of substandard Mooney butadiene rubber in the existing butadiene rubber polymerization production.

[0008] One of the technical solutions of this invention is achieved through the following measures: a method for controlling the polymerization reaction process in the production of butadiene rubber, comprising:

[0009] The first step is the control of the feeding stage: under the start-up feeding ratio, the raw material butadiene oil is heated by the preheater, and then the catalyst is sent to the polymerization reactor. During this process, the water content of the butadiene oil is controlled to be ≤20ppm. In the start-up feeding ratio, the concentration of butadiene in the butadiene oil is 1.1 to 2.5 times that of the butadiene concentration in the normal production ratio, and the amount of catalyst added is 1.05 times and 1.30 times that of the catalyst added in the normal production ratio.

[0010] The second step, initiation stage control: Butyl oil and catalyst are mixed in the first polymerization reactor and the polymerization reaction is initiated. The initiation stage control includes: First, when the bottom temperature of the first polymerization reactor is detected to be higher than the feed temperature of butyl oil, and the temperature difference between the bottom temperature of the first polymerization reactor and the feed temperature of butyl oil is 25°C to 50°C, the bottom temperature of the first polymerization reactor is reduced to 60°C to 85°C by a precooler; then, the concentration of butyl oil and the amount of catalyst added are reduced to the normal production ratio.

[0011] The third step is polymerization stage control: After the polymerization reaction is initiated, the polymerization reaction temperature of the first polymerization reactor is controlled. Polymerization stage control includes controlling the polymerization reaction temperature of the first polymerization reactor to 60°C to 85°C by cascading the bottom temperature of the first polymerization reactor with the outlet temperatures of the precooler and preheater.

[0012] The following are further optimizations and / or improvements to one of the above-mentioned technical solutions:

[0013] In the first step above, butadiene oil is a mixture of butadiene and solvent oil. The solvent oil is one of aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons. The concentration of butadiene in butadiene oil is 10g / 100mL to 45g / 100mL.

[0014] In the first step above, the feed temperature of the butadiene oil after being heated by the preheater is 30°C to 60°C.

[0015] The polybutadiene rubber produced by the above-mentioned method for controlling the polymerization reaction process is rare earth polybutadiene rubber or nickel-based polybutadiene rubber.

[0016] When producing rare earth butadiene rubber, the catalyst is a rare earth catalyst, which consists of a homogeneous rare earth catalyst and an aluminum agent. The homogeneous rare earth catalyst is neodymium carboxylate, and the aluminum agent is diisobutylaluminum hydride.

[0017] When producing rare earth butadiene rubber, the water content of the butadiene oil is ≤15ppm, preferably ≤5ppm. When the water content of the butadiene oil increases by 1ppm, the molar ratio of aluminum agent to butadiene increases by 0.005 to 0.025.

[0018] When producing rare earth cis-butadiene rubber, the molar ratio of homogeneous rare earth catalyst to butadiene is 2.5 × 10⁻⁶. -5 Up to 6.5×10 -5 The molar ratio of aluminum to butadiene is 1.25 × 10⁻⁶. -4 Up to 6.50×10 -4 .

[0019] When producing nickel-based cis-butadiene rubber, the catalyst is a nickel-based catalyst, which consists of an aluminum agent, a nickel agent, and a boron agent. The aluminum agent is triisobutylaluminum, the nickel agent is nickel naphthenate, and the boron agent is boron trifluoride diethyl ether complex.

[0020] When producing nickel-based butadiene rubber, the water content of the butadiene oil is 5 ppm to 20 ppm, preferably 8 ppm to 15 ppm. When the water content of the butadiene oil increases by 1 ppm, the molar ratio of aluminum agent to butadiene increases by 0.01 to 0.03.

[0021] In the production of nickel-based cis-butadiene rubber, the first step also includes water as a raw material. Butadiene oil and water are mixed and heated in a preheater, then mixed with a catalyst and sent to the polymerization reactor to initiate the reaction.

[0022] When producing nickel-based cis-butadiene rubber, the molar ratio of aluminum to butadiene is 0.15 × 10⁻⁶. -4 Up to 0.35×10 -4 The molar ratio of nickel to butadiene is 0.5 × 10⁻⁶. -5 Up to 1.6×10 -5 The molar ratio of boron agent to butadiene is 0.55 × 10⁻⁶. -4 Up to 1.1×10 -4 The mass ratio of water added to butadiene is 0.007 to 0.022.

[0023] The second technical solution of the present invention is achieved through the following measures: an apparatus for controlling the polymerization reaction process in the production of butadiene rubber, comprising a precooler, a preheater, a first polymerization reactor, an intermediate polymerization reactor, a final polymerization reactor, a first mixer, a second mixer, a third mixer, controller A, and controller B. A solvent oil feed line is fixedly connected to the inlet of the first mixer. A butadiene feed line is fixedly connected to the solvent oil feed line. A butadiene-water feed line is fixedly connected to the solvent oil feed line between the butadiene feed line and the first mixer. A first processing line is fixedly connected between the outlet of the first mixer and the inlet of the precooler. A second processing line is fixedly connected between the outlet of the precooler and the inlet of the preheater. A third processing line is fixedly connected between the outlet of the preheater and the inlet of the third mixer. A fourth processing line is fixedly connected between the outlet of the third mixer and the bottom inlet of the first polymerization reactor. A homogeneous rare earth catalyst / nickel agent feed line is fixedly connected to the inlet of the second mixer. An aluminum agent feed line is fixedly connected to the homogeneous rare earth catalyst / nickel agent feed line. A fifth processing pipeline is fixedly connected between the outlet of the reactor and the third processing pipeline. A boron feed pipeline is fixedly connected to the fourth processing pipeline. A sixth processing pipeline is fixedly connected between the top outlet of the first polymerization reactor and the bottom inlet of the intermediate polymerization reactor. A seventh processing pipeline is fixedly connected between the top outlet of the intermediate polymerization reactor and the bottom inlet of the final polymerization reactor. An eighth processing pipeline is fixedly connected to the top outlet of the final polymerization reactor. A first temperature detector is installed on the second processing pipeline. A second temperature detector is installed on the third processing pipeline between the preheater and the fifth processing pipeline. A third temperature detector is installed at the bottom of the first polymerization reactor. Chilled water inlet and outlet are fixedly connected to the cold source inlet and outlet of the precooler, respectively. Low-pressure steam inlet and condensate outlet are fixedly connected to the heat source inlet and outlet of the preheater, respectively. A first electrically controlled valve is installed on the chilled water outlet pipeline of the precooler. A second electrically controlled valve is installed on the low-pressure steam inlet pipeline. The first, second, and third temperature detectors are electrically connected to controller A, and controller A is electrically connected to the first and second electrically controlled valves, respectively.

[0024] The following are further optimizations and / or improvements to the second technical solution of the above invention:

[0025] A first online moisture analyzer is installed on the solvent oil feed line between the butadiene feed line and the butadiene water feed line. A bypass line is fixedly connected to the inlet and outlet of the preheater. A second online moisture analyzer is installed on the bypass line. An aluminum agent flow controller is also installed on the aluminum agent feed line. A butadiene water flow controller is installed on the butadiene water feed line. The first online moisture analyzer and the second online moisture analyzer are electrically connected to controller B, and controller B is electrically connected to the aluminum agent flow controller and the butadiene water flow controller.

[0026] In the production of butadiene rubber according to this invention, firstly, the polymerization reaction is initiated by controlling the feeding and initiation stages. Specifically, the butadiene oil concentration and catalyst addition are increased to initiate the polymerization reaction. Then, when the polymerization temperature reaches a predetermined value, the butadiene oil concentration and catalyst addition are reduced to achieve a stable polymerization reaction. Next, during the polymerization stage, when the quality of raw materials or catalyst fluctuates, the polymerization temperature of the first reactor is maintained by interlocking the bottom temperature of the first reactor, the outlet temperature of the precooler, and the outlet temperature of the preheater, ensuring stable polymerization. Finally, when the moisture content of the raw materials fluctuates, the aluminum agent formulation is pre-adjusted by setting a proportional relationship between the change in moisture content and the adjustment of the aluminum agent formulation, thus controlling the stability of the polymerization reaction. Through the control method of the polymerization reaction process in the production of butadiene rubber according to this invention, the Mooney (ML(1+4)100℃) of the obtained butadiene rubber is within the range of 41 to 49, which is considered acceptable. This effectively solves the problems of uncontrolled polymerization initiation during the feeding and start-up process, the risk of explosive polymerization, and the unacceptable Mooney of the produced butadiene rubber in existing butadiene rubber polymerization production. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the process flow of Embodiment 17 of the present invention.

[0028] The codes in the attached diagram are as follows: 1 for precooler, 2 for preheater, 3 for first polymerization reactor, 4 for intermediate polymerization reactor, 5 for final polymerization reactor, 6 for first mixer, 7 for second mixer, 8 for third mixer, 9 for controller A, 10 for controller B, 11 for solvent oil feed line, 12 for butadiene feed line, 13 for butadiene water feed line, 14 for first processing line, 15 for second processing line, 16 for third processing line, 17 for fourth processing line, 18 for homogeneous rare earth catalyst / nickel agent feed line, 19 for aluminum agent feed line, and 20 for fifth processing line. 21 is the boron agent feed line, 22 is the sixth processing line, 23 is the seventh processing line, 24 is the eighth processing line, 25 is the first temperature detector, 26 is the second temperature detector, 27 is the third temperature detector, 28 is the chilled water inlet line, 29 is the chilled water outlet line, 30 is the low-pressure steam inlet line, 31 is the condensate outlet line, 32 is the first electrically controlled valve, 33 is the second electrically controlled valve, 34 is the first online moisture analyzer, 35 is the bypass line, 36 is the second online moisture analyzer, 37 is the aluminum agent flow controller, and 38 is the butadiene water addition flow controller. Detailed Implementation

[0029] This invention is not limited to the following embodiments, and specific implementation methods can be determined according to the technical solutions and actual conditions of this invention. Unless otherwise specified, all chemical reagents and chemicals mentioned in this invention are well-known and commonly used chemical reagents and chemicals in the prior art; unless otherwise specified, all percentages in this invention are mass percentages; unless otherwise specified, all solutions in this invention are aqueous solutions with water as the solvent, for example, hydrochloric acid solution is an aqueous solution of hydrochloric acid; room temperature in this invention generally refers to a temperature between 15°C and 25°C, generally defined as 25°C.

[0030] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0031] The present invention will be further described below with reference to embodiments:

[0032] Example 1: As Figure 1 As shown, the method for controlling the polymerization reaction process in the production of butadiene rubber includes:

[0033] The first step, feeding stage control: Under the start-up feeding ratio, butadiene oil is heated through preheater 2, and then the catalyst is sent to the polymerization reactor 3. During this process, the water content of butadiene oil is controlled to be ≤20ppm. In the start-up feeding ratio, the concentration of butadiene in butadiene oil is 1.1 to 2.5 times that of butadiene in the normal production ratio, and the amount of catalyst added is 1.05 times and 1.30 times that of catalyst added in the normal production ratio.

[0034] The second step, initiation stage control: Butyl oil and catalyst are mixed in the polymerization reactor 3 and the polymerization reaction is initiated. The initiation stage control includes: First, when the bottom temperature of the polymerization reactor 3 is detected to be higher than the feed temperature of butyl oil, and the temperature difference between the bottom temperature of the polymerization reactor 3 and the feed temperature of butyl oil is 25°C to 50°C, the bottom temperature of the polymerization reactor 3 is reduced to 60°C to 85°C by the precooler 1; then, the concentration of butyl oil and the amount of catalyst added are reduced to the normal production ratio.

[0035] The third step is polymerization stage control: After the polymerization reaction is initiated, the polymerization reaction temperature of the first polymerization reactor 3 is controlled. The polymerization stage control includes controlling the polymerization reaction temperature of the first polymerization reactor 3 to 60°C to 85°C by cascading the bottom temperature of the first polymerization reactor 3 with the outlet temperatures of the precooler 1 and the preheater 2 respectively.

[0036] Example 2: As an optimization of the above example, in the first step, the butadiene oil is a mixture of butadiene and solvent oil, and the solvent oil is one of aliphatic hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons. The concentration of butadiene in the butadiene oil is 10g / 100mL to 45g / 100mL.

[0037] Example 3: As an optimization of the above example, in the first step, the feed temperature of the butadiene oil after being heated by the preheater 2 is 30°C to 60°C.

[0038] Example 4: As an optimization of the above examples, the cis-butadiene rubber produced by the method of controlling the polymerization reaction process in the production of cis-butadiene rubber is rare earth cis-butadiene rubber or nickel-based cis-butadiene rubber.

[0039] Example 5: As an optimization of the above example, when producing rare earth cis-butadiene rubber, the catalyst is a rare earth catalyst, which is composed of a homogeneous rare earth catalyst and an aluminum agent. The homogeneous rare earth catalyst is neodymium carboxylate, and the aluminum agent is diisobutylaluminum hydride.

[0040] Example 6: As an optimization of the above examples, when producing rare earth cis-butadiene rubber, the molar ratio of homogeneous rare earth catalyst to butadiene is 2.5 × 10⁻⁶. -5 Up to 6.5×10 -5 The molar ratio of aluminum to butadiene is 1.25 × 10⁻⁶. -4 Up to 6.50×10 -4 .

[0041] Example 7: As an optimization of the above example, when producing rare earth cis-butadiene rubber, the water content of butadiene oil is ≤15ppm, preferably ≤5ppm. When the water content of butadiene oil increases by 1ppm, the molar ratio of aluminum agent to butadiene increases by 0.005 to 0.025.

[0042] Example 8: As an optimization of the above example, when producing nickel-based cis-butadiene rubber, the catalyst is a nickel-based catalyst, which is composed of an aluminum agent, a nickel agent, and a boron agent. The aluminum agent is triisobutylaluminum, the nickel agent is nickel naphthenate, and the boron agent is boron trifluoride diethyl ether complex.

[0043] Example 9: As an optimization of the above examples, when producing nickel-based cis-butadiene rubber, the molar ratio of aluminum agent to butadiene is 0.15 × 10⁻⁶. -4 Up to 0.35×10 -4 The molar ratio of nickel to butadiene is 0.5 × 10⁻⁶. -5 Up to 1.6×10 -5 The molar ratio of boron agent to butadiene is 0.55 × 10⁻⁶. -4 Up to 1.1×10 -4 The water addition ratio to butadiene mass is 0.007 to 0.022.

[0044] Example 10: As an optimization of the above example, when producing nickel-based cis-butadiene rubber, the raw materials in the first step also include water. Butadiene oil and water are mixed and heated by preheater 2, and then mixed with catalyst and sent to polymerization reactor 3.

[0045] Example 11: As an optimization of the above embodiment, when producing nickel-based cis-butadiene rubber, the water content of the butadiene oil is 5ppm to 20ppm, preferably 8ppm to 15ppm. When the water content of the butadiene oil increases by 1ppm, the molar ratio of aluminum agent to butadiene increases by 0.01 to 0.03.

[0046] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0047] First, in this invention, by controlling the feeding stage and the initiation stage, on the one hand, the polymerization initiation of butadiene rubber during the polymerization process can be controlled, avoiding explosive polymerization. On the other hand, under strict control of the start-up feeding ratio and the normal production ratio, the butadiene rubber produced in the final polymerization reactor 5 is qualified, and the Mooney (ML(1+4)100℃) of the butadiene rubber is 41 to 49, which meets the standard requirements.

[0048] Secondly, in this invention, by controlling the polymerization stage, when the quality of raw materials or catalyst fluctuates, the bottom temperature of the first polymerization reactor 3 is controlled in series with the outlet temperatures of the precooler 1 and the preheater 2 respectively. When the bottom temperature of the first polymerization reactor 3 is too high, the cold source of the precooler 1 is controlled to cool down the bottom temperature of the first polymerization reactor 3. When the temperature of the first polymerization reactor 3 is too low, the preheater 2 is controlled to raise the bottom temperature of the first polymerization reactor 3, maintaining the polymerization reaction temperature of the first polymerization reactor 3 at 60°C to 85°C. This eliminates the need for manual control by operators, maintains the normal operation of the polymerization reaction, keeps the polymerization reaction in a stable state, and enables stable control of the quality of the polymer solution and the polymerization conversion rate in the first polymerization reactor 3.

[0049] Third, when the moisture content of the raw materials fluctuates, the aluminum agent formula can be pre-adjusted by setting a corresponding proportional relationship between the change in the moisture content of the raw materials and the adjustment of the aluminum agent formula, thereby controlling the stability of the polymerization reaction and reducing product quality fluctuations. The butadiene rubber plant generates approximately 300 tons of substandard material annually due to fluctuations in the moisture content of the raw materials. After the improvement of this invention, the aluminum agent can be pre-adjusted according to the change in the moisture content of the raw materials, avoiding the introduction of substandard products due to fluctuations in the moisture content. The price difference between superior and substandard products is approximately 3000 yuan / ton of rubber, resulting in an annual efficiency increase of 300 * 3000 = 900,000 yuan.

[0050] Fourth, for the production of rare earth butadiene rubber, two online water analyzers are set up. When the difference between the first online water content analyzer 34 and the second online water content analyzer 36 is less than 15, and for every 1 ppm increase in the butadiene oil water content, the flow rate of the aluminum agent flow controller 37 on the aluminum agent feed line 19 is increased, so that the molar ratio of aluminum agent to butadiene increases by 0.005 to 0.025. When the difference between the first online water content analyzer 34 and the second online water content analyzer 36 is greater than 15 and is too large, it indicates that the precooler 1 has an internal leak, and the unit needs to be isolated or the precooler 1 needs to be shut down for maintenance.

[0051] Fifth, for the production of nickel-based butadiene rubber, two online water analyzers are installed. When the difference between the first online water content analyzer 34 and the second online water content analyzer 36 is within the range of 5 ppm to 20 ppm, and for every 1 ppm increase in the butadiene oil water content, the flow rate of the aluminum agent flow controller 37 on the aluminum agent feed line 19 is increased, thereby increasing the molar ratio of aluminum agent to butadiene by 0.01 to 0.03. When the difference between the first online water content analyzer 34 and the second online water content analyzer 36 is < 5 ppm, it indicates that the butadiene oil water content is low, and the butadiene content is controlled. The butadiene water addition flow control valve on the water inlet pipeline 13 increases the flow rate of butadiene water addition. When the difference between the first online moisture content analyzer 34 and the second online moisture content analyzer 36 is >20ppm, it indicates that the butadiene oil water content is high. The butadiene water addition flow control valve on the butadiene water inlet pipeline 13 is then controlled to reduce the flow rate of butadiene water addition. When the difference between the first online moisture content analyzer 34 and the second online moisture content analyzer 36 exceeds the set value and is too large, it may indicate that the precooler 1 has an internal leak. The device needs to be isolated or the precooler 1 needs to be shut down for maintenance.

[0052] In summary, the method for controlling the polymerization reaction process in the production of butadiene rubber according to the present invention results in a Mooney (ML(1+4)100℃) of the obtained butadiene rubber within the range of 41 to 49, which is qualified. This effectively solves the problems of uncontrolled polymerization during the feeding and start-up process, the risk of explosive polymerization, and the unqualified Mooney of the produced butadiene rubber in the existing butadiene rubber polymerization production.

[0053] Example 12:

[0054] like Figure 1 As shown, the method for controlling the polymerization reaction process in the production of cis-butadiene rubber (production of rare earth cis-butadiene rubber) includes:

[0055] The first step, feeding stage: Under the starting feeding ratio (as shown in Table 1), butadiene and solvent oil are mixed and then heated to the feed temperature of butadiene oil of 38°C by preheater 2 (the cold source of precooler 1 is not used in this feeding stage). The heated butadiene oil, together with homogeneous rare earth catalyst (neodymium carboxylate) and aluminum agent (hydrogenated diisobutylaluminum), is sent to the polymerization reactor 3.

[0056] The second step, the initiation stage: When the bottom temperature of the polymerization reactor 3 is detected to be higher than the feed temperature of butadiene oil and the temperature difference between the bottom temperature of the polymerization reactor 3 and the feed temperature of butadiene oil gradually increases from 0℃ to 30℃, the bottom temperature of the polymerization reactor 3 is reduced and controlled to 65℃ by the precooler 1, and the concentration of butadiene oil and the amount of catalyst added are reduced to the normal production ratio (as shown in Table 1). The polymerization reaction is carried out under the normal production ratio. In the start-up feed ratio, the concentration of butadiene in butadiene oil is 1.3 times that of butadiene in the normal production ratio, and the amount of catalyst added is 1.08 times that of catalyst added in the normal production ratio.

[0057] The third step, polymerization stage: After the polymerization reaction is initiated, the bottom temperature of the first polymerization reactor 3 is controlled in series with the outlet temperatures of the precooler 1 and the preheater 2 (when the bottom temperature of the first polymerization reactor 3 is too high, the precooler 1 is controlled to cool down the bottom temperature of the first polymerization reactor 3; when the temperature of the first polymerization reactor 3 is too low, the preheater 2 is controlled to raise the bottom temperature of the first polymerization reactor 3). The polymerization reaction temperature of the first polymerization reactor 3 is maintained at 65°C. The polybutadiene-containing rubber solution obtained in the first polymerization reactor 3 is then sent to the intermediate polymerization reactor 4 (reaction temperature 90°C) and the final polymerization reactor 5 (reaction temperature 100°C) for continuous polymerization reaction. The product obtained in the final polymerization reactor 5 is rare earth cis-butadiene rubber.

[0058] Table 1 Material Proportioning for Rare Earth Cis-Butadiene Rubber Production Line

[0059] .

[0060] According to the method for controlling the polymerization reaction process in the production of butadiene rubber as described in Example 12 of this invention, the Mooney (ML(1+4)100℃) of the rare earth butadiene rubber obtained in the final polymerization reactor 5 is 46.0, and the conversion rate of the raw material butadiene is 97%.

[0061] Example 13:

[0062] like Figure 1 As shown, the method for controlling the polymerization reaction process in the production of cis-butadiene rubber (production of rare earth cis-butadiene rubber) includes:

[0063] The first step, feeding stage: Under the starting feeding ratio (as shown in Table 2), butadiene and solvent oil are mixed and then heated to the feed temperature of butadiene oil in preheater 2 to 40°C (the cold source of precooler 1 is not used in this feeding stage). The heated butadiene oil, together with homogeneous rare earth catalyst (neodymium carboxylate) and aluminum agent (hydrogenated diisobutylaluminum), is sent to the polymerization reactor 3.

[0064] The second step, the initiation stage: When the bottom temperature of the polymerization reactor 3 is detected to be higher than the feed temperature of butadiene oil and the temperature difference between the bottom temperature of the polymerization reactor 3 and the feed temperature of butadiene oil gradually increases from 0℃ to 35℃, the bottom temperature of the polymerization reactor 3 is reduced and controlled to 67℃ by the precooler 1, and the concentration of butadiene oil and the amount of catalyst added are reduced to the normal production ratio (as shown in Table 2). The polymerization reaction is carried out under the normal production ratio. In the start-up feed ratio, the concentration of butadiene in butadiene oil is 1.25 times that of butadiene in the normal production ratio, and the amount of catalyst added is 1.06 times that of catalyst added in the normal production ratio.

[0065] The third step, polymerization stage: After the polymerization reaction is initiated, the bottom temperature of the first polymerization reactor 3 is controlled in series with the outlet temperatures of precooler 1 and preheater 2 (when the bottom temperature of the first polymerization reactor 3 is too high, the precooler 1 is controlled to cool the bottom temperature of the first polymerization reactor 3; when the temperature of the first polymerization reactor 3 is too low, the preheater 2 is controlled to raise the bottom temperature of the first polymerization reactor 3), maintaining the polymerization reaction temperature of the first polymerization reactor 3 at 67°C. The polybutadiene-containing rubber solution obtained in the first polymerization reactor 3 is then sequentially sent to the intermediate polymerization reactor 4 (reaction temperature 90°C) and the final polymerization reactor 5 (reaction temperature 100°C) for continuous polymerization. The product obtained in the final polymerization reactor 5 is rare earth cis-butadiene rubber.

[0066] During the polymerization stage, when the moisture content of the raw material butadiene oil fluctuated, it was detected that the moisture content of butadiene oil decreased from 15 ppm to 10 ppm. At this time, the molar ratio of aluminum agent (diisobutylaluminum hydride) to butadiene was reduced by 0.05 (when the moisture content of butadiene oil increases by 1 ppm, the molar ratio of aluminum agent to butadiene increases by 0.01; when the moisture content of butadiene oil decreases by 1 ppm, the molar ratio of aluminum agent to butadiene decreases by 0.01), that is, from 3.4 to 3.35. The aluminum agent formulation was adjusted to maintain the stability of the polymerization reaction.

[0067] Table 2 Material Proportioning for Rare Earth Cis-Butadiene Rubber Production Line

[0068] .

[0069] According to the method for controlling the polymerization reaction process in the production of butadiene rubber as described in Example 13 of this invention, the Mooney (ML(1+4)100°C) of the rare earth butadiene rubber obtained in the final polymerization reactor 5 is 46.5 (the target value of Mooney (ML(1+4)100°C) is 41 to 49), and the conversion rate of the raw material butadiene is 98%.

[0070] Comparative Example 1:

[0071] The method for controlling the polymerization reaction process in the production of cis-butadiene rubber (production of rare earth cis-butadiene rubber):

[0072] Under normal production ratios (as shown in Table 1), butadiene and solvent oil are mixed and fed together with homogeneous rare earth catalyst (neodymium carboxylate) and aluminum agent (hydrogenated diisobutylaluminum) into the first polymerization reactor 3. After polymerization at a bottom temperature of 65°C, the polybutadiene-containing rubber solution flows out from the top of the first polymerization reactor 3 and is sequentially sent to the intermediate polymerization reactor 4 (reaction temperature of 90°C) and the final polymerization reactor 5 (reaction temperature of 100°C) for continuous polymerization. The product obtained from the final polymerization reactor 5 is rare earth cis-butadiene rubber.

[0073] According to the control method of the polymerization reaction process in the production of butadiene rubber described in Comparative Example 1, the Mooney (ML(1+4)100℃) of the rare earth butadiene rubber obtained in the final polymerization reactor 5 is 39, and the conversion rate of the raw material butadiene is 75%.

[0074] Example 14:

[0075] like Figure 1 As shown, the method for controlling the polymerization reaction process in the production of butadiene rubber (for nickel-based butadiene rubber) includes:

[0076] The first step, feeding stage: Under the starting feeding ratio (as shown in Table 3), butadiene, solvent oil and water are mixed and then heated to the feed temperature of butadiene oil in preheater 2 to 50°C (the cold source of precooler 1 is not used in this feeding stage). The heated butadiene oil, together with aluminum agent (triisobutylaluminum), nickel agent (nickel naphthenate) and boron agent (boron trifluoride diethyl ether complex), is sent to the polymerization reactor 3.

[0077] The second step, the initiation stage: When the bottom temperature of the polymerization reactor 3 is detected to be higher than the feed temperature of butadiene oil and the temperature difference between the bottom temperature of the polymerization reactor 3 and the feed temperature of butadiene oil gradually increases from 0℃ to 30℃, the bottom temperature of the polymerization reactor 3 is reduced and controlled to 68℃ by the precooler 1, and the concentration of butadiene oil and the amount of catalyst added are reduced to the normal production ratio (as shown in Table 3). The polymerization reaction is carried out under the normal production ratio. In the start-up feed ratio, the concentration of butadiene in butadiene oil is 2.0 times that of butadiene in the normal production ratio, and the amount of catalyst added is 1.1 times that of catalyst added in the normal production ratio.

[0078] The third step, polymerization stage: After the polymerization reaction is initiated, the bottom temperature of the first polymerization reactor 3 is controlled in series with the outlet temperatures of the precooler 1 and the preheater 2 (when the bottom temperature of the first polymerization reactor 3 is too high, the precooler 1 is controlled to cool down the bottom temperature of the first polymerization reactor 3; when the temperature of the first polymerization reactor 3 is too low, the preheater 2 is controlled to raise the bottom temperature of the first polymerization reactor 3). The polymerization reaction temperature of the first polymerization reactor 3 is maintained at 68°C. The polybutadiene-containing rubber solution obtained in the first polymerization reactor 3 is then sent to the intermediate polymerization reactor 4 (reaction temperature 90°C) and the final polymerization reactor 5 (reaction temperature 100°C) for continuous polymerization reaction. The product obtained in the final polymerization reactor 5 is nickel-based cis-butadiene rubber.

[0079] Table 3 Material Proportions for Nickel-Based Cis-Butadiene Rubber Production Line

[0080] .

[0081] According to the method for controlling the polymerization reaction process in the production of butadiene rubber as described in Example 14 of this invention, the Mooney (ML(1+4)100℃) of the nickel-based butadiene rubber obtained in the final polymerization reactor 5 is 44.0, and the conversion rate of the raw material butadiene is 84%.

[0082] Example 15:

[0083] like Figure 1 As shown, the method for controlling the polymerization reaction process in the production of butadiene rubber (for nickel-based butadiene rubber) includes:

[0084] The first step, feeding stage: Under the starting feeding ratio (as shown in Table 4), butadiene, solvent oil and water are mixed and then heated to the feed temperature of butadiene oil of 40°C by preheater 2 (the cold source of precooler 1 is not used in this feeding stage). The heated butadiene oil is sent to the polymerization reactor 3 together with aluminum agent (triisobutylaluminum), nickel agent (nickel naphthenate) and boron agent (boron trifluoride diethyl ether complex).

[0085] The second step, the initiation stage: When the bottom temperature of the polymerization reactor 3 is detected to be higher than the feed temperature of butadiene oil and the temperature difference between the bottom temperature of the polymerization reactor 3 and the feed temperature of butadiene oil gradually increases from 0℃ to 35℃, the bottom temperature of the polymerization reactor 3 is reduced and controlled to 65℃ by the precooler 1, and the concentration of butadiene oil and the amount of catalyst added are reduced to the normal production ratio (as shown in Table 4). Under the normal production ratio, the normal polymerization reaction begins. In the start-up feed ratio, the concentration of butadiene in butadiene oil is 2.0 times that of butadiene in the normal production ratio, and the amount of catalyst added is 1.05 times that of catalyst added in the normal production ratio.

[0086] The third step, polymerization stage: After the polymerization reaction is initiated, the bottom temperature of the first polymerization reactor 3 is controlled in cascade with the outlet temperatures of precooler 1 and preheater 2 (when the bottom temperature of the first polymerization reactor 3 is too high, the precooler 1 is controlled to cool the bottom temperature of the first polymerization reactor 3; when the temperature of the first polymerization reactor 3 is too low, the preheater 2 is controlled to raise the bottom temperature of the first polymerization reactor 3), maintaining the polymerization reaction temperature of the first polymerization reactor 3 at 65°C. The polybutadiene-containing rubber solution obtained in the first polymerization reactor 3 is then sequentially sent to the intermediate polymerization reactor 4 (reaction temperature 90°C) and the final polymerization reactor 5 (reaction temperature 100°C) for continuous polymerization. The product obtained in the final polymerization reactor 5 is nickel-based cis-butadiene rubber;

[0087] During the polymerization stage, when the moisture content of the raw material butadiene oil fluctuates, it is detected that the moisture content of butadiene oil increases from 10 ppm to 15 ppm. At this time, the molar ratio of aluminum agent (triisobutylaluminum) to butadiene is increased by 0.1 (when the moisture content of butadiene oil increases by 1 ppm, the molar ratio of aluminum agent to butadiene increases by 0.02), that is, from 0.2 to 0.3. The aluminum agent formula is adjusted to maintain the stability of the polymerization reaction.

[0088] Table 4 Material Proportions for Nickel-Based Cis-Butadiene Rubber Production Line

[0089] .

[0090] According to the method for controlling the polymerization reaction process in the production of butadiene rubber as described in Example 15 of this invention, the Mooney (ML(1+4)100℃) of the rare earth butadiene rubber obtained in the final polymerization reactor 5 is 43.5, and the conversion rate of the raw material butadiene is 85%.

[0091] Comparative Example 2:

[0092] The method for controlling the polymerization process in the production of butadiene rubber (for nickel-based butadiene rubber):

[0093] Under normal production ratios (as shown in Table 3), butadiene, solvent oil, and water are mixed and fed together with aluminum agent (triisobutylaluminum), nickel agent (nickel naphthenate), and boron agent (boron trifluoride ether complex) into the first polymerization reactor 3. The polymerization reaction is carried out at a bottom temperature of 65°C. The polybutadiene-containing rubber solution flows out from the top of the first polymerization reactor 3 and is successively sent to the intermediate polymerization reactor 4 (reaction temperature of 90°C) and the final polymerization reactor 5 (reaction temperature of 100°C) for continuous polymerization reaction. The product obtained from the final polymerization reactor 5 is nickel-based cis-butadiene rubber.

[0094] Following the control method of the polymerization reaction process in the production of butadiene rubber described in Comparative Example 2, the Mooney (ML(1+4)100℃) of the obtained nickel-based butadiene rubber was 39, and the conversion rate of the raw material butadiene was 72%.

[0095] Example 16:

[0096] like Figure 1 As shown, the apparatus for controlling the polymerization reaction process in the production of butadiene rubber includes a precooler 1, a preheater 2, a first polymerization reactor 3, an intermediate polymerization reactor 4, a final polymerization reactor 5, a first mixer 6, a second mixer 7, a third mixer 8, a controller A9, and a controller B10. The inlet of the first mixer 6 is fixedly connected to a solvent oil feed line 11, and a butadiene feed line 12 is fixedly connected to the solvent oil feed line 11. A butadiene water feed line 13 is fixedly connected to the solvent oil feed line 11 between the butadiene feed line 12 and the first mixer 6. The outlet of the first mixer 6 is connected to the precooler 1. A first processing pipeline 14 is fixedly connected between the inlet of precooler 1 and the inlet of preheater 2. A second processing pipeline 15 is fixedly connected between the outlet of preheater 1 and the inlet of preheater 2. A third processing pipeline 16 is fixedly connected between the outlet of preheater 2 and the inlet of third mixer 8. A fourth processing pipeline 17 is fixedly connected between the outlet of third mixer 8 and the bottom inlet of polymerization reactor 3. A homogeneous rare earth catalyst / nickel agent feed pipeline 18 is fixedly connected to the inlet of second mixer 7. An aluminum agent feed pipeline 19 is fixedly connected to the homogeneous rare earth catalyst / nickel agent feed pipeline 18. The outlet of second mixer 7 is fixedly connected to the third processing pipeline 16. There is a fifth processing pipeline 20. A boron feed pipeline 21 is fixedly connected to the fourth processing pipeline 17. A sixth processing pipeline 22 is fixedly connected between the top outlet of the first polymerization reactor 3 and the bottom inlet of the intermediate polymerization reactor 4. A seventh processing pipeline 23 is fixedly connected between the top outlet of the intermediate polymerization reactor 4 and the bottom inlet of the final polymerization reactor 5. An eighth processing pipeline 24 is fixedly connected to the top outlet of the final polymerization reactor 5. A first temperature detector 25 is installed on the second processing pipeline 15. A second temperature detector 26 is installed on the third processing pipeline 16 between the preheater 2 and the fifth processing pipeline 20. A third temperature detector is installed at the bottom of the first polymerization reactor 3. Temperature detector 27, chilled water inlet pipeline 28 and chilled water outlet pipeline 29 are fixedly connected to the cold source inlet and outlet of precooler 1, respectively, and low-pressure steam inlet pipeline 30 and condensate outlet pipeline 31 are fixedly connected to the heat source inlet and outlet of preheater 2, respectively. A first solenoid valve 32 is provided on chilled water outlet pipeline 29 of precooler 1, and a second solenoid valve 33 is provided on low-pressure steam inlet pipeline 30. The first temperature detector 25, the second temperature detector 26 and the third temperature detector 27 are electrically connected to controller A9, and controller A9 is electrically connected to the first solenoid valve 32 and the second solenoid valve 33, respectively.

[0097] Example 17: As Figure 1As shown, as an optimization of the above embodiment, a first online moisture analyzer 34 is provided on the solvent oil feed line 11 between the butadiene feed line 12 and the butadiene water feed line 13. A bypass line 35 is fixedly connected to the inlet and outlet of the preheater 2. A second online moisture analyzer 36 is provided on the bypass line 35. An aluminum agent flow controller 37 is also provided on the aluminum agent feed line 19. A butadiene water feed line 13 is provided with a butadiene water flow controller 38. The first online moisture analyzer 34 and the second online moisture analyzer 36 are electrically connected to the controller B10, and the controller B10 is electrically connected to the aluminum agent flow controller 37 and the butadiene water flow controller 38, respectively.

[0098] When producing rare earth butadiene rubber, the butadiene water feed line 13 and the butadiene water flow controller 38 are stopped. That is, the first online moisture analyzer 34 and the second online moisture analyzer 36 are electrically connected to the controller B10, and the controller B10 is electrically connected to the aluminum agent flow controller 37.

[0099] In this apparatus, the first polymerization reactor 3, the intermediate polymerization reactor 4, the final polymerization reactor 5, the preheater 2, and the precooler 1 are all existing, commonly known and commonly used equipment. Controllers A and B both use the SW-TIC-2 model. The various pipelines and equipment in this apparatus may also be equipped with conventional valves, thermometers, pressure gauges, and flow meters, etc., which are commonly known and commonly used in the art, according to production needs.

[0100] The apparatus for controlling the polymerization reaction process in the production of cis-butadiene rubber according to the present invention has the following process flow when producing rare earth cis-butadiene rubber:

[0101] First, the feeding stage: the butadiene water feed line 13 and the boron agent feed line 21 are shut down. Under the start-up feeding ratio, butadiene and solvent oil are sent to the first mixer 6 for mixing, and then sent to the preheater 2 for heating. The feed temperature of butadiene oil is monitored by the second temperature detector and controlled between 30°C and 60°C (the cold source of the precooler 1 is not used at first). The homogeneous rare earth catalyst (neodymium carboxylate) and aluminum agent (hydrogenated diisobutylaluminum) are sent to the second mixer 7 for mixing, and together with the heated butadiene oil, they are sent to the third mixer 8 for mixing. The material mixed in the third mixer 8 is sent to the polymerization reactor 3.

[0102] The second step, the initiation stage: When the bottom temperature of the polymerization reactor 3 detected by the third temperature detector 27 is higher than the feed temperature of butadiene oil detected by the second temperature detector 26, and the difference between the bottom temperature of the third temperature detector 27 (bottom temperature of the polymerization reactor 3) and the second temperature detector 26 (feed temperature of butadiene oil) is 25°C to 50°C, at this time, the first electrically controlled valve 32 on the chilled water outlet pipeline 29 of the precooler 1 is opened by the controller A9 to reduce the bottom temperature of the polymerization reactor 3 to 65°C. At the same time, the concentration of butadiene oil and the amount of catalyst added are reduced, and the polymerization reaction begins under normal production ratio.

[0103] The third step, polymerization stage: When the quality of raw materials or the amount of catalyst added fluctuates, the controller A9 receives temperature signals from the third temperature detector 27 (bottom temperature of polymerization reactor 3), the first temperature detector 25 (outlet temperature of precooler 1), and the second temperature detector 26 (outlet temperature of preheater 2). The controller A9 then controls the opening and closing of the first and second solenoid valves 32 and 33 to maintain the bottom temperature of polymerization reactor 3 at 60°C to 85°C. (Specifically, when the quality of raw materials or the amount of catalyst added fluctuates, the third temperature detector 27 detects the bottom temperature of polymerization reactor 3.) When the temperature is below 60℃ to 85℃, the controller A9 controls the second solenoid valve 33 to open. The opening degree of the second solenoid valve 33 is 1% to 5%, maintained for 2 to 10 minutes, to achieve a bottom temperature of 60℃ to 85℃ in the first polymerization reactor 3. Similarly, when the third temperature detector 27 detects that the bottom temperature is above 60℃ to 85℃, the controller A9 controls the first solenoid valve 32 to open. The polybutadiene-containing rubber solution obtained in the first polymerization reactor 3 is sequentially sent to the intermediate polymerization reactor 4 and the final polymerization reactor 5 for continuous polymerization reaction. The product obtained in the final polymerization reactor 5 is rare earth cis-butadiene rubber.

[0104] During the polymerization stage, when the moisture content of the raw material fluctuates, the controller B10 controls the flow rate of the aluminum agent to increase by 0.005 to 0.025 when the difference between the first online moisture content analyzer 34 and the second online moisture content analyzer 36 is less than 15, and the moisture content of the butadiene oil increases by 1 ppm.

[0105] When the difference between the first online moisture analyzer 34 and the second online moisture analyzer 36 is detected to be greater than 15 and is too large, it indicates that the precooler 1 has an internal leak, and the device needs to be isolated or shut down for maintenance.

[0106] The apparatus for controlling the polymerization reaction process in the production of butadiene rubber according to the present invention, when producing nickel-based butadiene rubber, has the following process flow:

[0107] Step 1, Feeding Stage: Start the butadiene-water feed line 13 and the boron agent feed line 21. Under the start-up feeding ratio, send butadiene, solvent oil and water to the first mixer 6 for mixing, and then send them to the preheater 2 for heating. The feed temperature of the butadiene oil is monitored by the second temperature detector and controlled between 30°C and 60°C (the cold source of the precooler 1 is not used at the beginning). Send the aluminum agent (triisobutylaluminum) and nickel agent (nickel naphthenate) to the second mixer 7 for mixing. The material in the second mixer 7 and the heated butadiene oil are sent to the third mixer 8 for mixing. The mixed material in the third mixer 8 and the boron agent (boron trifluoride diethyl ether complex) are sent to the polymerization reactor 3.

[0108] The second step, the initiation stage: When the bottom temperature of the polymerization reactor 3 detected by the third temperature detector 27 is higher than the feed temperature of butadiene oil detected by the second temperature detector 26, and the difference between the bottom temperature of the third temperature detector 27 (bottom temperature of the polymerization reactor 3) and the second temperature detector 26 (feed temperature of butadiene oil) is 25°C to 50°C, at this time, the first electrically controlled valve 32 on the chilled water outlet pipeline 29 is opened by the controller A9 to reduce the bottom temperature of the polymerization reactor 3 to 65°C. At the same time, the concentration of butadiene oil and the amount of catalyst added are reduced, and the polymerization reaction begins under normal production ratio.

[0109] The third step, polymerization stage: When the quality of raw materials or the amount of catalyst added fluctuates, the controller A9 receives temperature signals from the third temperature detector 27 (bottom temperature of polymerization reactor 3), the first temperature detector 25 (outlet temperature of precooler 1), and the second temperature detector 26 (outlet temperature of preheater 2). The controller A9 then controls the opening and closing of the first and second solenoid valves 32 and 33 to maintain the bottom temperature of polymerization reactor 3 at 60°C to 85°C. (Specifically, when the quality of raw materials or the amount of catalyst added fluctuates, the third temperature detector 27 at the bottom of polymerization reactor 3 detects...) When the bottom temperature is below 60℃ to 85℃, the controller A9 controls the second solenoid valve 33 to open. The opening degree of the second solenoid valve 33 is 1% to 5%, maintained for 2 minutes to 10 minutes, to achieve a bottom temperature of 60℃ to 85℃ in the first polymerization reactor 3. Similarly, when the third temperature detector 27 detects that the bottom temperature is above 60℃ to 85℃, the controller A9 controls the first solenoid valve 32 to open. The polybutadiene-containing rubber solution obtained from the first polymerization reactor 3 is sequentially sent to the intermediate polymerization reactor 4 and the final polymerization reactor 5 for continuous polymerization reaction. The product obtained in the final polymerization reactor 5 is rare earth cis-butadiene rubber.

[0110] During the polymerization stage, when the moisture content of the raw material fluctuates, the controller B10 controls the flow rate of the aluminum agent on the aluminum agent feed line 19 to increase the flow rate of the aluminum agent flow controller 37 when the difference between the first online moisture content analyzer 34 and the second online moisture content analyzer 36 is detected to be within the range of 5ppm to 20ppm, and the moisture content of the butadiene oil increases by 1ppm. This increases the molar ratio of aluminum agent to butadiene by 0.01 to 0.03.

[0111] When the difference between the first online moisture analyzer 34 and the second online moisture analyzer 36 is less than 5 ppm, it indicates that the butadiene water content is low. Control the butadiene water flow control valve on the butadiene water feed pipeline 13 to increase the flow rate of butadiene water.

[0112] When the difference between the first online moisture analyzer 34 and the second online moisture analyzer 36 is greater than 20 ppm, it indicates that the butadiene water content is high. Control the butadiene water flow control valve on the butadiene water feed pipeline 13 to reduce the flow rate of butadiene water.

[0113] When the difference between the first online moisture analyzer 34 and the second online moisture analyzer 36 exceeds the set value and is too large, it may indicate that the precooler 1 has an internal leak, and the device needs to be isolated or shut down for maintenance.

[0114] In summary, the present invention addresses the following issues in the production of butadiene rubber: First, by controlling the feeding and initiation stages, specifically by increasing the butadiene oil concentration and catalyst dosage to initiate the polymerization reaction, and then reducing the butadiene oil concentration and catalyst dosage when the polymerization temperature reaches a predetermined value, the polymerization reaction reaches a stable state. Next, during the polymerization stage, when raw material or catalyst quality fluctuates, the polymerization temperature of the first reactor is maintained by interlocking the bottom temperature of the first reactor, the precooler outlet temperature, and the preheater outlet temperature, ensuring stable polymerization operation. Finally, when the moisture content of the raw materials fluctuates, the aluminum agent formulation is pre-adjusted by setting a proportional relationship between the change in raw material moisture content and the adjustment of the aluminum agent formulation, thus controlling the stability of the polymerization reaction. Through the control method of the polymerization process in the production of butadiene rubber of the present invention, the Mooney (ML(1+4)100℃) of the obtained butadiene rubber is within the range of 41 to 49, meeting the Mooney standard. This effectively solves the problems of uncontrolled polymerization initiation during the feeding and start-up process, the risk of explosive polymerization, and the unqualified Mooney of the produced butadiene rubber in existing butadiene rubber polymerization production.

[0115] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A method of controlling the polymerization process in the production of butadiene rubber, characterized by The butadiene rubber is a rare earth butadiene rubber or a nickel butadiene rubber, and a control method thereof comprises the following steps: In the first step, a feeding stage control, the raw material butadiene oil is heated by a preheater, and then the catalyst is sent to a polymerization first reactor, wherein the water content of the butadiene oil is controlled to be less than or equal to 20 ppm, the concentration of butadiene in the butadiene oil is 1.1 to 2.5 times of the concentration of butadiene in the normal production ratio, the addition amount of the catalyst is 1.05 times or 1.30 times of the addition amount of the catalyst in the normal production ratio, the butadiene oil is a mixture of butadiene and solvent oil, the solvent oil is one of aliphatic hydrocarbons, alicyclic hydrocarbons and aromatic hydrocarbons, and the concentration of butadiene in the butadiene oil is 10 g / 100 mL to 45 g / 100 mL; In the second step, an initiation stage control, the butadiene oil and the catalyst are mixed in the polymerization first reactor to initiate the polymerization reaction, wherein the initiation stage control comprises the following steps: firstly, when it is detected that the bottom temperature of the polymerization first reactor is higher than the feeding temperature of the butadiene oil, and the temperature difference between the bottom temperature of the polymerization first reactor and the feeding temperature of the butadiene oil is 25 ℃ to 50 ℃, the bottom temperature of the polymerization first reactor is reduced to 60 ℃ to 85 ℃ by a pre-cooler; and then, the concentration of the butadiene oil and the addition amount of the catalyst are reduced to the normal production ratio; In the third step, a polymerization stage control, after the initiation of the polymerization reaction, the polymerization reaction temperature of the polymerization first reactor is controlled, wherein the polymerization stage control comprises the following steps: the polymerization reaction temperature of the polymerization first reactor is controlled to be 60 ℃ to 85 ℃ by controlling the bottom temperature of the polymerization first reactor in series with the outlet temperature of the pre-cooler and the outlet temperature of the preheater, respectively.

2. The method of controlling the polymerization process in the production of butadiene rubber according to claim 1, characterized in that In the first step, the feeding temperature of the butadiene oil after being heated by the preheater is 30 ℃ to 60 ℃.

3. The method of controlling the polymerization process in the production of butadiene rubber according to claim 1 or 2, characterized in that When the rare earth butadiene rubber is produced, the catalyst is a rare earth catalyst, the rare earth catalyst is composed of a homogeneous rare earth catalyst and an aluminum agent, the homogeneous rare earth catalyst is neodymium carboxylate, and the aluminum agent is diisobutyl aluminum hydride.

4. The method of controlling the polymerization process in the production of butadiene rubber according to claim 3, characterized in that When producing rare earth butadiene rubber, the molar ratio of homogeneous rare earth catalyst to butadiene is 2.5 x 10 -5 to 6.5 x 10 -5 , and the molar ratio of aluminum agent to butadiene is 1.25 x 10 -4 to 6.50 x 10 -4 .

5. The method of controlling the polymerization process in the production of butadiene rubber according to claim 4, characterized in that When the rare earth butadiene rubber is produced, the water content of the butadiene oil is less than or equal to 15 ppm, and when the water content of the butadiene oil is detected to increase by 1 ppm, the molar ratio of the aluminum agent to butadiene is increased by 0.005 to 0.

025.

6. The method of controlling the polymerization process in the production of butadiene rubber according to claim 1 or 2, characterized in that When the nickel butadiene rubber is produced, the catalyst is a nickel catalyst, the nickel catalyst is composed of an aluminum agent, a nickel agent and a boron agent, the aluminum agent is triisobutyl aluminum, the nickel agent is nickel naphthenate, and the boron agent is boron trifluoride ether complex; or / and, when the nickel butadiene rubber is produced, in the first step, the raw material further comprises water, the butadiene oil and the water are mixed and then heated by the preheater, and then the catalyst is sent to the polymerization first reactor.

7. The method of controlling the polymerization process in the production of butadiene rubber according to claim 6, characterized in that When producing nickel-based butadiene rubber, the molar ratio of aluminum agent to butadiene is 0.15 x 10 -4 to 0.35 x 10 -4 , the molar ratio of nickel agent to butadiene is 0.5 x 10 -5 to 1.6 x 10 -5 , the molar ratio of boron agent to butadiene is 0.55 x 10 -4 to 1.1 x 10 -4 , the mass ratio of water addition to butadiene is 0.007 to 0.022; or / and, when producing nickel-based butadiene rubber, the water content of but oil is 5 ppm to 20 ppm, and when the water content of but oil is detected to increase by 1 ppm, the molar ratio of aluminum agent to butadiene is increased by 0.01 to 0.

03.

8. An apparatus for carrying out the control method of the polymerization reaction process in the production of butadiene rubber according to any one of claims 3 to 7, characterized by The application relates to a butadiene polymerization system, which comprises a pre-cooler, a pre-heater, a first polymerization reactor, a second polymerization reactor, a third polymerization reactor, a first mixer, a second mixer, a third mixer, a controller A and a controller B, a solvent oil feeding pipeline is fixedly connected to the inlet of the first mixer, a butadiene feeding pipeline is fixedly connected to the solvent oil feeding pipeline, a butadiene water feeding pipeline is fixedly connected to the solvent oil feeding pipeline between the butadiene feeding pipeline and the first mixer, a first treatment pipeline is fixedly connected between the outlet of the first mixer and the inlet of the pre-cooler, a second treatment pipeline is fixedly connected between the outlet of the pre-cooler and the inlet of the pre-heater, a third treatment pipeline is fixedly connected between the outlet of the pre-heater and the inlet of the third mixer, a fourth treatment pipeline is fixedly connected between the outlet of the third mixer and the bottom inlet of the first polymerization reactor, a homogeneous rare earth catalyst / nickel agent feeding pipeline is fixedly connected to the inlet of the second mixer, an aluminum agent feeding pipeline is fixedly connected to the homogeneous rare earth catalyst / nickel agent feeding pipeline, a fifth treatment pipeline is fixedly connected between the outlet of the second mixer and the third treatment pipeline, a boron agent feeding pipeline is fixedly connected to the fourth treatment pipeline, a sixth treatment pipeline is fixedly connected between the top outlet of the first polymerization reactor and the bottom inlet of the second polymerization reactor, a seventh treatment pipeline is fixedly connected between the top outlet of the second polymerization reactor and the bottom inlet of the third polymerization reactor, an eighth treatment pipeline is fixedly connected to the top outlet of the third polymerization reactor, a first temperature detector is arranged on the second treatment pipeline, a second temperature detector is arranged on the third treatment pipeline between the pre-heater and the fifth treatment pipeline, and a third temperature detector is arranged on the bottom of the first polymerization reactor, the inlet and the outlet of the pre-cooler cold source are fixedly connected with a refrigerated water inlet pipeline and a refrigerated water outlet pipeline, the inlet and the outlet of the pre-heater heat source are fixedly connected with a low-pressure steam inlet pipeline and a condensate outlet pipeline, a first electric control valve is arranged on the refrigerated water outlet pipeline of the pre-cooler, a second electric control valve is arranged on the low-pressure steam inlet pipeline, the first temperature detector, the second temperature detector and the third temperature detector are electrically connected with the controller A, and the controller A is electrically connected with the first electric control valve and the second electric control valve.

9. The apparatus of claim 8, wherein A first online water content analyzer is arranged on the solvent oil feeding pipeline between the butadiene feeding pipeline and the butadiene water feeding pipeline, a bypass pipeline is fixedly connected to the inlet and the outlet of the pre-heater, a second online water content analyzer is arranged on the bypass pipeline, an aluminum agent flow controller is arranged on the aluminum agent feeding pipeline, a butadiene water flow controller is arranged on the butadiene water feeding pipeline, the first online water content analyzer and the second online water content analyzer are electrically connected with the controller B, and the controller B is electrically connected with the aluminum agent flow controller and the butadiene water flow controller.

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