Continuous loop hydrogenation system for preparing styrene-based elastomer and production method

Abstract

The invention belongs to the field of elastomer preparation, and particularly relates to a continuous loop hydrogenation system for preparing a styrene-based elastomer and a production method. The invention provides a continuous loop hydrogenation system for preparing a styrene-based elastomer, which comprises a pre-hydrogenation reactor, a loop hydrogenation reactor, a post-hydrogenation reactor, a gas-liquid separation tank, a mixing tank and a delivery pump, wherein the pre-hydrogenation reactor, the loop hydrogenation reactor, the post-hydrogenation reactor, the gas-liquid separation tank and the mixing tank are sequentially connected in series according to the reaction direction. According to the technical scheme provided by the invention, the problems of complicated operation, high hydrogen consumption, low hydrogenation efficiency and the like in a traditional kettle type hydrogenation process are solved, the production efficiency is improved, the energy consumption is reduced, and the consistency of product quality is enhanced.

Description

Technical Field

[0001] The present application belongs to the field of elastomer preparation, and in particular relates to a continuous loop hydrogenation system and production method for preparing styrene-based elastomers. Background Art

[0002] In the field of elastomer materials, the hydrogenation products of styrene-isoprene-styrene block copolymer (SIS), styrene-ethylene-propylene-styrene block copolymer (SEPS), and the hydrogenation products of styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene-butylene-styrene block copolymer (SEBS), are favored in high-end applications due to their excellent physical properties and stability. However, the current processes for producing these high-performance elastomers mainly rely on kettle hydrogenation or fixed-bed hydrogenation technology. Although these methods can meet basic production needs, they expose a series of problems in actual operation.

[0003] Traditional kettle hydrogenation processes usually involve intermittent operation modes, which means that each reaction requires complex preparation, startup process and subsequent processing steps. Frequent switching of control valves not only increases the difficulty of operation, but also has an adverse effect on the service life of the equipment. In addition, since various additives need to be added after the unreacted hydrogen is discharged in each kettle reaction, this not only leads to a waste of hydrogen resources, but also increases production costs. What is more serious is that this intermittent operation mode is prone to quality fluctuations between different batches of products, and it is difficult to ensure the consistency and stability of product quality. Moreover, the kettle hydrogenation effect is not good, and the material concentration can often only be maintained at about 10%, which not only limits the production efficiency, but also increases the energy consumption in the subsequent solvent recovery process.

[0004] Although fixed-bed hydrogenation technology is superior to kettle hydrogenation in some aspects, it also has its inherent limitations. For example, the replacement cycle of fixed-bed catalysts is long. Once blockage or deactivation occurs, it will directly affect the operating efficiency of the entire production line. In addition, the process of replacing catalysts is complicated and time-consuming, further increasing maintenance costs. In addition, the fixed-bed hydrogenation process has poor adaptability to raw materials and is difficult to process raw materials containing more impurities. This puts higher requirements on the selection of raw materials and indirectly increases the cost of raw material procurement.

[0005] Generally speaking, the existing hydrogenation processes are unable to meet the growing market demand for high-performance elastomers. From the perspectives of operation complexity, resource utilization efficiency, and product quality consistency, the existing technologies face numerous challenges. The existence of these problems not only restricts the improvement of the economic benefits of production enterprises but also limits to a certain extent the application scope and development potential of high-performance elastomer materials. Therefore, seeking a more efficient, stable, and economical hydrogenation production process has become an urgent problem to be solved in the current industry. Summary of the Invention

[0006] To solve the above problems, the present application provides a continuous loop hydrogenation system and production method for preparing styrenic elastomers, achieving deep hydrogenation, improving the hydrogenation efficiency, increasing the solid content to 20%, reducing the energy consumption of solvent removal in subsequent production processes, avoiding the disadvantages of multiple hydrogen emissions in batch processes, and reducing hydrogen consumption.

[0007] The present application provides a continuous loop hydrogenation system for preparing styrenic elastomers, including a pre-hydrogenation reactor, a loop hydrogenation reactor, a post-hydrogenation reactor, a gas-liquid separation tank, a blending tank, and a transfer pump. The pre-hydrogenation reactor, the loop hydrogenation reactor, the post-hydrogenation reactor, the gas-liquid separation tank, and the blending tank are sequentially connected in series according to the reaction direction; the transfer pump is arranged on the pipeline connecting the pre-hydrogenation reactor and the loop hydrogenation reactor.

[0008] Furthermore, the pre-hydrogenation reactor at least includes a pre-hydrogenation reactor a and a pre-hydrogenation reactor b; the transfer pumps include a pre-hydrogenation discharge pump a and a pre-hydrogenation discharge pump b. The pre-hydrogenation discharge pump a is arranged on the pipeline connecting the pre-hydrogenation reactor a and the pre-hydrogenation reactor b, and the pre-hydrogenation discharge pump b is arranged on the pipeline connecting the pre-hydrogenation reactor b and the loop hydrogenation reactor.

[0009] Furthermore, the loop hydrogenation reactor is provided with a Venturi ejector.

[0010] Furthermore, the loop hydrogenation reactor is provided with a loop hydrogenation reactor pump, one end of which is connected to the outlet of the loop hydrogenation reactor and the other end is connected to the inlet of the loop hydrogenation reactor.

[0011] The present application provides a continuous loop hydrogenation production method for preparing styrenic elastomers, including the following steps: S1. Add the unhydrogenated elastomer solution and initiator to the pre-hydrogenation reactor and introduce hydrogen for reaction; S2. After the reaction is completed, the reaction material in the pre-hydrogenation reactor is transported to the loop hydrogenation reactor through the pre-hydrogenation discharge pump, and hydrogen and the main catalyst are introduced into the loop hydrogenation reactor for loop hydrogenation; S3. The reaction materials in the loop hydrogenation reactor enter the post-hydrogenation reactor for post-hydrogenation reaction; S4. The materials in the post-hydrogenation reactor enter the gas-liquid separation tank for material separation; S5. The products separated by the gas-liquid separation tank enter the blending tank.

[0012] This application also provides a continuous loop hydrogenation production method for preparing styrenic elastomers, including the following steps: S1. Add the unhydrogenated elastomer solution and initiator to the pre-hydrogenation reactor a, and introduce hydrogen for reaction; S2. The reaction materials in the pre-hydrogenation reactor a are transported to the pre-hydrogenation reactor b by the pre-hydrogenation discharge pump a, and a cocatalyst is added simultaneously for reaction; S3. After the reaction, the reaction materials in the pre-hydrogenation reactor b are transported to the loop hydrogenation reactor by the pre-hydrogenation discharge pump b, and hydrogen and the main catalyst are introduced into the loop hydrogenation reactor for loop hydrogenation; S4. The reaction materials in the loop hydrogenation reactor enter the post-hydrogenation reactor for post-hydrogenation reaction; S5. The materials in the post-hydrogenation reactor enter the gas-liquid separation tank for material separation; S6. The products separated by the gas-liquid separation tank enter the blending tank.

[0013] Furthermore, the unhydrogenated elastomer is a styrene-butadiene-styrene block copolymer.

[0014] Furthermore, the unhydrogenated elastomer is a styrene-isoprene-styrene block copolymer.

[0015] Furthermore, the initiator is butyl lithium, the cocatalyst is an aromatic compound, and the main catalyst is a metallocene catalyst; the aromatic compound is one or more of dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diisooctyl phthalate, and hexamethylphosphoric triamide; the titanium-based catalyst is one of dicyclopentadienyl titanium dichloride, dicyclopentadienyl titanium dibromide, dicyclopentadienyl dimethyl titanium, dicyclopentadienyl diphenyl titanium, dicyclopentadienyl dimethylxenyl titanium, dicyclopentadienyl dimethoxy titanium, and dicyclopentadienyl dicarbonyl titanium.

[0016] Furthermore, the reaction system and reaction method provided by this application can be applicable to various hydrogenation catalytic systems, such as various homogeneous catalytic systems such as organic acid salts, palladium acetate, and tetraalkyl titanium.

[0017] The organic acid salt is a mixture of organic acid nickel such as nickel naphthenate, nickel 2-ethylacetate, nickel octanoate, etc. and alkyl metal compounds such as n-butyl aluminum, sec-butyl aluminum, triisobutyl aluminum, and triethyl aluminum.

[0018] The tetraalkyltitanium catalytic system generally uses tetraalkyltitanium compounds as the main catalyst, such as tetrabenzyltitanium, tetraphenyltitanium, tetrakis(4-methylphenyl)titanium), tetrakis(2,3-dimethylbenzyl)titanium, diphenyldibenzyltitanium, etc., and uses organic compounds with one or more ester functional groups, such as p-hydroxybenzoic acid esters, dimethyl oxalate, methyl formate, etc., as co-catalysts.

[0019] The reaction temperature of step S1 is 70-90°C, the pressure is 0.2-0.6MPa, and the reaction time is 1-2h; the reaction temperature of step S2 is 70-90°C, the pressure is 0.2-0.6MPa, and the reaction time is 0.2-0.6h; the loop hydrogenation temperature of step S3 is 90-105°C, the pressure is 1.5-1.9MPa, and the reaction time is 2-4h; the post-hydrogenation reaction temperature of step S4 is 90-105°C, the pressure is 1.0-1.3MPa, and the residence time is 0.3-0.6h; the temperature of the gas-liquid separation tank of step S5 is 80-100°C, and the pressure is 0.1MPa.

[0020] The present application aims to realize an efficient and continuous loop hydrogenation preparation process for styrene-based elastomers, such as SEPS and SEBS. In terms of system structure, this scheme includes components such as pre-hydrogenation reactors a and b, a loop hydrogenation reactor, a post-hydrogenation reactor, a gas-liquid separation tank, and a blending tank, which are connected by a delivery pump system. First, in the pre-hydrogenation reactor a, the unhydrogenated elastomer solution is mixed with an initiator and hydrogen is introduced. Subsequently, the material is transported to the pre-hydrogenation reactor b via the pre-hydrogenation discharge pump a, where a co-catalyst is added for secondary pretreatment to further optimize the reaction conditions and improve the conversion rate and selectivity. This step-by-step pre-hydrogenation strategy helps to gradually regulate the reaction environment, thereby providing a basis for subsequent deep hydrogenation.

[0021] After entering the loop hydrogenation reactor, the material is efficiently contacted with different phases through the action of the Venturi ejector and the circulation pump. The main catalyst is introduced at this stage, and the enhanced mixing effect brought by the Venturi effect is combined to promote deep hydrogenation. The material coming out of the loop hydrogenation reactor then enters the post-hydrogenation reactor, where the hydrogen dissolved in the material is further hydrogenated. This stage extends the hydrogenation time, ensures the thoroughness of the reaction, and thus improves the performance of the final product. The hydrogenated material then enters the gas-liquid separation tank to remove unreacted hydrogen and other gas impurities, reduce the impact of these components on product quality, and simplify subsequent processing steps. Finally, the separated liquid product enters the blending tank, and the finished product composition is adjusted according to specific application requirements to ensure that it meets the expected physical and chemical properties, such as hardness, elasticity, and heat resistance.

[0022] The present application also provides a continuous loop hydrogenation production method for preparing styrenic elastomers. Combined with system improvements, it shows significant advantages in increasing the solid content. First of all, in existing technologies such as traditional batch hydrogenation processes, due to their intermittent operation mode, the preparatory work, start-up process, and subsequent treatment steps before and after each reaction are complex and time-consuming. This not only increases the operation difficulty but also has an adverse impact on the equipment life. More importantly, this intermittent operation is difficult to maintain stable reaction conditions, resulting in large quality fluctuations between different batches of products and limiting the increase in solid content, which can usually only be maintained at about 10%. In addition, the frequent discharge of unreacted hydrogen not only wastes resources but also increases production costs.

[0023] The present application uses a continuous production process instead of intermittent operation, reducing complex preparatory work and subsequent treatment steps, ensuring the stability and consistency of reaction conditions, which is crucial for supporting efficient reactions at high solid contents. Secondly, the loop hydrogenation reactor in this system is equipped with a Venturi ejector and an efficient circulation mechanism, which greatly promotes the mixing efficiency between the gas and liquid phases, enabling hydrogen to be more evenly dispersed in the liquid, thereby improving gas utilization and reaction efficiency. Even at high solid contents, good hydrogenation effects can be ensured. In addition, the new production method adopts a staged reaction strategy, including pre-hydrogenation, loop hydrogenation, and then post-hydrogenation processes, adjusting reaction conditions according to the requirements of each stage to ensure ideal hydrogenation depth even under high solid content conditions. At the same time, the reasonable distribution and use of catalysts further improve the hydrogenation efficiency, enabling high conversion rates to be obtained even when there are more solid substances. These improvements work together not only to improve the mass transfer efficiency of the entire system, reduce the amount of solvent required to achieve the same reaction effect compared with existing technologies, thereby allowing higher solid contents without affecting product performance and reaction effects, but also to enhance the material fluidity, solving common problems such as difficult stirring or material accumulation at high solid contents.

[0024] In summary, by introducing a continuous loop hydrogenation system, combined with measures such as optimized mixing mechanisms, enhanced mass transfer efficiency, and reduced unnecessary operation steps, many limitations in traditional processes have been overcome, achieving the goal of increasing the solid content from the traditional level to 20%. This progress not only improves production efficiency and product quality but also reduces costs and resource consumption, providing strong support for the manufacture of high-performance elastomer materials and laying a solid foundation for their wide application.

[0025] One of the key advantages of the method provided by this application is the ability to achieve efficient hydrogenation reactions at relatively low temperatures. This low-temperature operation not only does not affect the reaction efficiency, but can also bring beneficial effects. It improves production efficiency and resource utilization rate, reduces costs, more raw materials are converted into target products, reduces the formation of unnecessary by-products, makes the produced polymers more in line with the expected performance requirements, and may reduce the need for subsequent processing steps. For catalysts, the low-temperature environment helps to extend their service life. Many catalysts lose their activity when exposed to high temperatures for a long time, while low-temperature operating conditions can slow down this process, thereby reducing the frequency and cost of catalyst replacement, while maintaining the stability and continuity of the production process. At the same time, reducing the reaction temperature means reducing the energy required to heat the reaction system, which is particularly important for large-scale industrial production. The lower operating temperature also enhances the safety of the process and reduces the potential risks brought by high temperatures.

[0026] Through the effective combination of equipment and methods, this solution not only solves the problems existing in the traditional batch hydrogenation process, such as complex operation, high hydrogen consumption, and unstable product quality between batches, but also realizes the improvement of production efficiency, the reduction of energy consumption, and the enhancement of product quality consistency. In addition, this continuous production mode also has a high degree of flexibility, can quickly respond to changes in market demand, and greatly enhances the adaptability and economic benefits of production. Brief Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of a continuous loop hydrogenation system for preparing styrenic elastomers.

[0028] In the figure: 1. Pre-hydrogenation reactor a; 11. Pre-hydrogenation reactor b; 2. Loop hydrogenation reactor; 201. Venturi ejector; 202. Loop hydrogenation reactor pump; 3. Post-hydrogenation reactor; 4. Gas-liquid separation tank; 5. Blending tank; 601. Pre-hydrogenation discharge pump a; 62. Pre-hydrogenation discharge pump b. Detailed Embodiments

[0029] The technical solutions and their effects of the present invention are further described below through specific embodiments. The following embodiments are only used to illustrate the content of the present invention and are not used to limit the protection scope of the present invention. Simple changes made to the present invention using the concept of the present invention are within the scope of protection required by the present invention.

[0030] The equipment used in the preparation method of the present invention can all adopt well-known equipment in the field. The raw materials used in the present invention are commercially available unless otherwise specified.

[0031] Example 1 As Figure 1As shown, the present application provides a continuous loop hydrogenation system for preparing styrenic elastomers, including a pre-hydrogenation reactor, a loop hydrogenation reactor 2, a post-hydrogenation reactor 3, a gas-liquid separation tank 4, a blending tank 5 and a transfer pump. The pre-hydrogenation reactor, the loop hydrogenation reactor 2, the post-hydrogenation reactor 3, the gas-liquid separation tank 4 and the blending tank 5 are arranged in series in the reaction direction in sequence; the pre-hydrogenation reactor includes a pre-hydrogenation reactor a1 and a pre-hydrogenation reactor b11; the transfer pump includes a pre-hydrogenation discharge pump a601 and a pre-hydrogenation discharge pump b62. The pre-hydrogenation discharge pump a601 is arranged on the connecting pipeline between the pre-hydrogenation reactor a1 and the pre-hydrogenation reactor b11, and the pre-hydrogenation discharge pump b62 is arranged on the connecting pipeline between the pre-hydrogenation reactor b11 and the loop hydrogenation reactor 2. The loop hydrogenation reactor 2 is provided with a venturi ejector 201. The loop hydrogenation reactor 2 is provided with a loop hydrogenation reactor pump 202. One end of the loop hydrogenation reactor pump 202 is connected to the outlet of the loop hydrogenation reactor 2, and the other end is connected to the inlet of the loop hydrogenation reactor 2.

[0032] First, in the pre-hydrogenation stage, the system is configured with at least two pre-hydrogenation reactors, namely the pre-hydrogenation reactor a1 and the pre-hydrogenation reactor b11. The unhydrogenated elastomer solution raw material and the initiator react with hydrogen for the first time in the pre-hydrogenation reactor a1. Then, the material in the pre-hydrogenation reactor a1 is transported to the pre-hydrogenation reactor b11 through the pre-hydrogenation discharge pump a601, and a cocatalyst is added and mixed during this process. Here, the pre-hydrogenation discharge pump a601 is located on the connecting pipeline between the pre-hydrogenation reactor a1 and the pre-hydrogenation reactor b11, ensuring that the material can be smoothly transferred from one reactor to another. Subsequently, the material that has undergone two pre-hydrogenation treatments is transported to the loop hydrogenation reactor 2 through the pre-hydrogenation discharge pump b62. The loop hydrogenation reactor 2 is one of the key components of this system. It not only has a venturi ejector 201 to increase the contact area of different phases, adding the main catalyst to the reactor in a jet form to improve the hydrogenation efficiency, but also is equipped with a loop hydrogenation reactor pump 202. One end of this pump is connected to the outlet of the loop hydrogenation reactor 2, and the other end is connected back to the inlet, forming a closed loop, enabling the material to circulate within the reactor, promoting sufficient contact between the reactants, and thus enhancing the reaction effect. The material that has completed the loop hydrogenation reaction then enters the post-hydrogenation reactor 3, where further hydrogenation is carried out using the hydrogen dissolved in the material, extending the hydrogenation reaction time and improving the overall efficiency of the hydrogenation reaction. Then, the material in the post-hydrogenation reactor 3 flows into the gas-liquid separation tank 4 to achieve gas-liquid separation. The separated product finally enters the blending tank 5 for further processing or direct use.

[0033] The method provided in this embodiment is as follows: S1. Add the mixed raw material solution of styrene-butadiene-styrene block copolymer with a mass concentration of 20% and cyclohexane and the butyllithium solution to the pre-hydrogenation reactor a1, and introduce hydrogen for mixing; the solvent of the butyllithium solution is cyclohexane, with a mass concentration of 6%, the raw material flow rate is 15 t / h, the initiator flow rate is 80 L / h, the temperature is 75 °C, the pressure is 0.4 MPa, and the residence time is 1.5 h.

[0034] S2. Then, transfer the reaction materials in the pre-hydrogenation reactor a1 to the pre-hydrogenation reactor b11 through the pre-hydrogenation discharge pump a601, and simultaneously add the cocatalysts dimethyl phthalate and methyl o-toluate for cocatalysis. The addition amount of the cocatalysts is 30 L / h, the temperature is 75 °C, the pressure is 0.4 MPa, and the residence time is 0.4 h.

[0035] S3. Transfer the reaction materials in the pre-hydrogenation reactor b11 to the loop hydrogenation reactor 2 through the pre-hydrogenation discharge pump b62. Hydrogen and the main catalyst titanocene dichloride are introduced into the loop hydrogenation reactor 2 for loop hydrogenation; the addition amount of the catalyst is 0.8% of the mass of the reaction materials, the loop circulation volume is 4000 m 3 / h, the hydrogenation temperature is 100 °C, the hydrogenation pressure is 1.7 MPa, and the residence time is 2 h.

[0036] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor for post-hydrogenation reaction. The reaction temperature is 93 °C, the pressure is 1.0 MPa, and the residence time is 0.6 h.

[0037] S5. The materials in the post-hydrogenation reactor enter the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 80 °C, and the pressure is 0.1 MPa.

[0038] S6. The product separated from the gas-liquid separation tank 4 enters the blending tank 5. The temperature of the blending tank 5 is 80 °C and it is at atmospheric pressure.

[0039] Example 2 The continuous loop hydrogenation system for preparing styrenic elastomers used in this example is the same as that in Example 1. The production method is as follows: S1. Add the mixed raw material solution of styrene-butadiene-styrene block copolymer with a mass concentration of 15% and cyclohexane and the butyllithium solution to the pre-hydrogenation reactor a1, and introduce hydrogen for mixing; the solvent of the butyllithium solution is cyclohexane, with a mass concentration of 6%, the raw material flow rate is 15 t / h, the flow rate of the initiator butyllithium is 60 L / h, the temperature is 70 °C, the pressure is 0.2 MPa, and the residence time is 1 h.

[0040] S2. Then, the reaction materials in the pre-hydrogenation reactor a1 are transported to the pre-hydrogenation reactor b11 through the pre-hydrogenation discharge pump a601. Meanwhile, the cocatalysts dimethyl phthalate and methyl o-toluate are added for cocatalysis. The addition amount of the cocatalysts is 25 L / h, the temperature is 80 °C, the pressure is 0.2 MPa, and the residence time is 0.6 h.

[0041] S3. The reaction materials in the pre-hydrogenation reactor b11 are transported to the loop hydrogenation reactor 2 through the pre-hydrogenation discharge pump b62. Hydrogen and the main catalyst titanocene dichloride are introduced into the loop hydrogenation reactor 2 for loop hydrogenation; the addition amount of the catalyst is 0.8% of the mass of the reaction materials, the loop circulation rate is 4000 m 3 / h, the hydrogenation temperature is 90 °C, the hydrogenation pressure is 1.5 MPa, and the residence time is 2 h.

[0042] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor for post-hydrogenation reaction. The reaction temperature is 93 °C, the pressure is 1.1 MPa, and the residence time is 0.3 h.

[0043] S5. The materials in the post-hydrogenation reactor enter the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 90 °C, and the pressure is 0.1 MPa.

[0044] S6. The product separated from the gas-liquid separation tank 4 enters the blending tank 5. The temperature in the blending tank 5 is 80 °C, and the pressure is atmospheric pressure.

[0045] Example 3 The continuous loop hydrogenation system for preparing styrenic elastomer used in this example is the same as that in Example 1. The production method is as follows: S1. A raw material solution of a styrene-butadiene-styrene block copolymer with a mass concentration of 20% and cyclohexane, and a butyllithium solution are added to the pre-hydrogenation reactor a1, and hydrogen is introduced for mixing; the solvent of the butyllithium solution is cyclohexane, the mass concentration is 6%, the raw material flow rate is 15 t / h, the flow rate of the initiator butyllithium is 60 L / h, the temperature is 90 °C, the pressure is 0.6 MPa, and the residence time is 2 h.

[0046] S2. Then, the reaction materials in the pre-hydrogenation reactor a1 are transported to the pre-hydrogenation reactor b11 through the pre-hydrogenation discharge pump a601. Meanwhile, the cocatalysts dimethyl phthalate and methyl o-toluate are added for cocatalysis. The addition amount of the cocatalysts is 25 L / h, the temperature is 90 °C, the pressure is 0.2 MPa, and the residence time is 0.6 h.

[0047] S3. The reaction materials in the pre-hydrogenation reactor b11 are transported to the loop hydrogenation reactor 2 by the pre-hydrogenation discharge pump b62. Hydrogen and the main catalyst titanocene dichloride are introduced into the loop hydrogenation reactor 2 for loop hydrogenation; the addition amount of the catalyst is 0.8% of the mass of the reaction materials, and the loop circulation rate is 4000 m 3 / h, the hydrogenation temperature is 105 °C, the hydrogenation pressure is 1.9 MPa, and the residence time is 2 h.

[0048] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor for post-hydrogenation reaction. The reaction temperature is 93 °C, the pressure is 1.1 MPa, and the residence time is 0.3 h.

[0049] S5. The materials in the post-hydrogenation reactor enter the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 90 °C, and the pressure is 0.1 MPa.

[0050] S6. The product separated from the gas-liquid separation tank 4 enters the blending tank 5. The temperature of the blending tank 5 is 80 °C, and the pressure is atmospheric pressure.

[0051] Example 4 This application provides a continuous loop hydrogenation system for preparing styrenic elastomers, including a pre-hydrogenation reactor, a loop hydrogenation reactor 2, a post-hydrogenation reactor 3, a gas-liquid separation tank 4, a blending tank 5 and a transfer pump. The pre-hydrogenation reactor, the loop hydrogenation reactor 2, the post-hydrogenation reactor 3, the gas-liquid separation tank 4 and the blending tank 5 are arranged in series in the reaction direction in sequence; the pre-hydrogenation discharge pump is arranged on the connecting pipeline between the pre-hydrogenation reactor and the loop hydrogenation reactor 2. The loop hydrogenation reactor 2 is provided with a venturi ejector 201. The loop hydrogenation reactor 2 is provided with a loop hydrogenation reactor pump 202. One end of the loop hydrogenation reactor pump 202 is connected to the discharge port of the loop hydrogenation reactor 2, and the other end is connected to the feed port of the loop hydrogenation reactor 2.

[0052] The production method is as follows: S1. A mixed raw material solution of a 20% mass concentration styrene-isoprene-styrene block copolymer and cyclohexane and dimethyl phthalate are added to the pre-hydrogenation reactor, and hydrogen is introduced for mixing; the raw material flow rate is 15 t / h, the dimethyl phthalate flow rate is 30 L / h, the temperature is 75 °C, the pressure is 0.4 MPa, and the residence time is 1.5 h.

[0053] S2. The reaction materials in the pre-hydrogenation reactor are transported to the loop hydrogenation reactor 2 by the pre-hydrogenation discharge pump. Hydrogen and the main catalyst titanocene dichloride are introduced into the loop hydrogenation reactor 2 for loop hydrogenation; the addition amount of the catalyst is 0.8% of the mass of the reaction materials, and the loop circulation rate is 4000 m 3 / h, the hydrogenation temperature is 90 °C, the hydrogenation pressure is 1.7 MPa, and the residence time is 2 h.

[0054] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor to carry out the post-hydrogenation reaction. The reaction temperature is 93 °C, the pressure is 1.0 MPa, and the residence time is 0.6 h.

[0055] S5. The materials in the post-hydrogenation reactor enter the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 80 °C and the pressure is 0.1 MPa.

[0056] S6. The products separated from the gas-liquid separation tank 4 enter the blending tank 5. The temperature of the blending tank 5 is 80 °C and the pressure is atmospheric pressure.

Claims

1. A continuous loop hydrogenation system for preparing styrene-based elastomers, characterized in that: The invention comprises a pre-hydrogenation reactor, a loop hydrogenation reactor (2), a post-hydrogenation reactor (3), a gas-liquid separation tank (4), a blending tank (5) and a delivery pump, wherein the pre-hydrogenation reactor, the loop hydrogenation reactor (2), the post-hydrogenation reactor (3), the gas-liquid separation tank (4) and the blending tank (5) are sequentially arranged in series according to the reaction direction; and the delivery pump is arranged on the connecting pipeline between the pre-hydrogenation reactor and the loop hydrogenation reactor (2).

2. A continuous loop hydrogenation system for preparing styrene-based elastomers according to claim 1, characterized in that: The pre-hydrogenation reactor at least comprises a pre-hydrogenation reactor a (1) and a pre-hydrogenation reactor b (11); the delivery pump comprises a pre-hydrogenation discharge pump a (601) and a pre-hydrogenation discharge pump b (62), the pre-hydrogenation discharge pump a (601) being arranged on a connecting pipeline between the pre-hydrogenation reactor a (1) and the pre-hydrogenation reactor b (11), and the pre-hydrogenation discharge pump b (62) being arranged on a connecting pipeline between the pre-hydrogenation reactor b (11) and the loop hydrogenation reactor (2).

3. The continuous loop hydrogenation system for preparing styrene-based elastomers according to claim 1 or 2, characterized in that: The loop hydrogenation reactor (2) is provided with a Venturi injector (201).

4. The continuous loop hydrogenation system for preparing styrene-based elastomers according to claim 1 or 2, characterized in that: The loop hydrogenation reactor (2) is provided with a loop hydrogenation reactor pump (202), one end of the loop hydrogenation reactor pump (202) is connected to the discharge port of the loop hydrogenation reactor (2), and the other end is connected to the feed port of the loop hydrogenation reactor (2).

5. The continuous loop hydrogenation production method for styrene-based elastomers according to the continuous loop hydrogenation system for preparing styrene-based elastomers according to claim 1, characterized in that: The following steps are involved: S1. The unhydrogenated elastomer solution and the initiator are added to the pre-hydrogenation reactor, and hydrogen is introduced to react; S2. After the reaction is completed, the reaction material of the pre-hydrogenation reactor is transported to the loop hydrogenation reactor (2) by the pre-hydrogenation discharge pump, and hydrogen and the main catalyst are introduced into the loop hydrogenation reactor (2) for loop hydrogenation; S3. The reaction materials in the loop hydrogenation reactor (2) enter the post-hydrogenation reactor (3) for post-hydrogenation reaction; S4. The material in the post-hydrogenation reactor (3) enters the gas-liquid separation tank (4) for material separation; S5. The product separated from the gas-liquid separation tank (4) enters the blending tank (5).

6. The continuous loop hydrogenation production method for styrene-based elastomers according to the continuous loop hydrogenation system for preparing styrene-based elastomers according to claim 2, characterized in that: The following steps are involved: S1. The unhydrogenated elastomer solution and the initiator are added to the pre-hydrogenation reactor a (1), and hydrogen is introduced to react; S2. The reaction materials in the pre-hydrogenation reactor a (1) are transported to the pre-hydrogenation reactor b (11) through the pre-hydrogenation discharge pump a (601), and a promoter is added to react; S3. After the reaction is completed, the reaction material of the pre-hydrogenation reactor b (11) is transported to the loop hydrogenation reactor (2) through the pre-hydrogenation discharge pump b (62), and hydrogen and the main catalyst are introduced into the loop hydrogenation reactor (2) to perform loop hydrogenation; S4. The reaction materials in the loop hydrogenation reactor (2) enter the post-hydrogenation reactor (3) for post-hydrogenation reaction; S5. The material in the post-hydrogenation reactor (3) enters the gas-liquid separation tank (4) for material separation; S6. The product separated from the gas-liquid separation tank (4) enters the blending tank (5).

7. The continuous loop hydrogenation production method of styrene-based elastomer according to claim 5 or 6, characterized in that: The non-hydrogenated elastomer is a styrene-butadiene-styrene block copolymer.

8. The continuous loop hydrogenation production method of styrene-based elastomer according to claim 5 or 6, characterized in that: The non-hydrogenated elastomer is a styrene-isoprene-styrene block copolymer.

Images