A continuous loop hydrogenation system and production method for preparing styrene-based elastomers

Abstract

The present application belongs to the field of elastomer preparation, and particularly relates to a continuous loop hydrogenation system and production method for preparing styrene-based elastomers. The present application provides a continuous loop hydrogenation system for preparing styrene-based elastomers, comprising a pre-hydrogenation reactor, a loop hydrogenation reactor, a post-hydrogenation reactor, a gas-liquid separation tank, a blending 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 blending tank are sequentially arranged in series according to the reaction direction. The technical solution provided by the present application solves the problems of complex operation, high hydrogen consumption, low hydrogenation efficiency, etc. existing in the traditional kettle hydrogenation process, and realizes the improvement of production efficiency, the reduction of energy consumption and the enhancement of product quality consistency.

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, styrene-ethylene-propylene-styrene block copolymer (SEPS), a hydrogenated product of styrene-isoprene-styrene block copolymer (SIS), and styrene-ethylene-butylene-styrene block copolymer (SEBS), a hydrogenated product of styrene-butadiene-styrene block copolymer (SBS), are highly favored in high-end applications due to their excellent physical properties and stability. However, the current processes used to produce these high-performance elastomers mainly rely on autoclave hydrogenation or fixed-bed hydrogenation technologies. While these methods can meet basic production needs, they expose a series of problems during actual operation.

[0003] Traditional kettle hydrogenation processes usually involve an intermittent operation mode, which means that each reaction requires complex preparation work, 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 cause quality fluctuations between different batches of products, making it 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 production efficiency, but also increases energy consumption in the subsequent solvent recovery process.

[0004] While fixed-bed hydrogenation technology offers advantages over autoclave hydrogenation in some respects, it also has inherent limitations. For example, fixed-bed catalyst replacement cycles are long, and any blockage or deactivation can directly impact the efficiency of the entire production line. Furthermore, catalyst replacement is complex and time-consuming, further increasing maintenance costs. Furthermore, fixed-bed hydrogenation processes are less adaptable to feedstocks and struggle to process feedstocks high in impurities. This places higher demands on raw material selection, indirectly increasing procurement costs.

[0005] Overall, existing hydrogenation processes are struggling to meet the growing market demand for high-performance elastomers. Existing technologies face numerous challenges, including operational complexity, resource efficiency, and consistent product quality. These issues not only hinder the economic benefits of manufacturers but also, to a certain extent, limit the application scope and development potential of high-performance elastomer materials. Therefore, the search for a more efficient, stable, and economical hydrogenation production process has become a pressing issue for the industry. Summary of the Invention

[0006] In order to solve the above problems, the present application provides a continuous loop hydrogenation system and production method for preparing styrene-based elastomers, which realizes deep hydrogenation, improves hydrogenation efficiency, can increase the solid content to 20%, reduce the energy consumption of subsequent production process desolventization, avoids the shortcomings of multiple hydrogen emissions in intermittent processes, and reduces hydrogen consumption.

[0007] The present application provides a continuous loop hydrogenation system for preparing a styrene-based elastomer, comprising a pre-hydrogenation reactor, a loop hydrogenation reactor, a post-hydrogenation reactor, a gas-liquid separation tank, a blending 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 blending tank 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.

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

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

[0010] Furthermore, the loop hydrogenation reactor is provided with a loop hydrogenation reactor pump, one end of the loop hydrogenation reactor pump is connected to the discharge port of the loop hydrogenation reactor, and the other end is connected to the feed port of the loop hydrogenation reactor.

[0011] The present application provides a continuous loop hydrogenation production method for preparing a styrene-based elastomer, comprising the following steps:

[0012] S1. The unhydrogenated elastomer solution and the initiator are added to the pre-hydrogenation reactor and hydrogen is introduced to react;

[0013] S2. After the reaction is completed, the reaction material of the pre-hydrogenation reactor is transported to the loop hydrogenation reactor by a pre-hydrogenation discharge pump, and hydrogen and the main catalyst are introduced into the loop hydrogenation reactor for loop hydrogenation;

[0014] S3. The reaction materials in the loop hydrogenation reactor enter the post-hydrogenation reactor for post-hydrogenation reaction;

[0015] S4. The material in the post-hydrogenation reactor enters the gas-liquid separation tank for material separation;

[0016] S5. The product separated from the gas-liquid separation tank enters the blending tank.

[0017] The present application also provides a continuous loop hydrogenation production method for preparing a styrene-based elastomer, comprising the following steps:

[0018] S1. The unhydrogenated elastomer solution and the initiator are added to the pre-hydrogenation reactor a, and hydrogen is introduced to react;

[0019] S2 pre-hydrogenation reactor a reaction material is transported to the pre-hydrogenation reactor b by a pre-hydrogenation discharge pump, while adding a co-catalyst to react;

[0020] S3. After the reaction is completed, the reaction material of the pre-hydrogenation reactor b is 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;

[0021] S4. The reaction materials in the loop hydrogenation reactor enter the post-hydrogenation reactor for post-hydrogenation reaction;

[0022] S5. The material in the post-hydrogenation reactor enters the gas-liquid separation tank for material separation;

[0023] S6. The product separated from the gas-liquid separation tank enters the blending tank.

[0024] Furthermore, the non-hydrogenated elastomer is a styrene-butadiene-styrene block copolymer.

[0025] Furthermore, the non-hydrogenated elastomer is a styrene-isoprene-styrene block copolymer.

[0026] Furthermore, the initiator is butyl lithium, the co-catalyst 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; and the titanium-based catalyst is one of biscyclopentadiene titanium dichloride, biscyclopentadiene titanium dibromide, biscyclopentadiene dimethyl titanium, biscyclopentadiene diphenyl titanium, biscyclopentadiene ditolyl titanium, biscyclopentadiene dimethoxy titanium, and biscyclopentadiene dicarbonyl titanium.

[0027] Furthermore, the reaction system and reaction method provided in the present application can be applied to a variety of hydrogenation catalytic systems, such as various homogeneous catalytic systems such as organic acid salts, palladium acetate, and tetraalkyltitanium.

[0028] The organic acid salt is a mixture of organic acid nickel such as nickel naphthenate, 2-ethyl nickel acetate, nickel octoate, etc. and an alkyl metal compound such as n-butyl aluminum, sec-butyl aluminum, triisobutyl aluminum, triethyl aluminum, etc.

[0029] 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.

[0030] 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 gas-liquid separation tank temperature of step S5 is 80-100°C and the pressure is 0.1MPa.

[0031] The present application aims to realize an efficient 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.

[0032] 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 about by the Venturi effect promotes deep hydrogenation. The material coming out of the loop hydrogenation reactor then enters the post-hydrogenation reactor, where it is further hydrogenated using the hydrogen dissolved in the material. 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 gaseous 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.

[0033] The present application also provides a continuous loop hydrogenation production method for preparing styrene-based elastomers, which, combined with system improvements, shows significant advantages in improving solid content. First of all, existing technologies such as traditional kettle hydrogenation processes, due to their intermittent operating mode, the preparatory work before and after each reaction, the startup process and the subsequent processing steps are complicated and time-consuming, which not only increases the difficulty of operation, but also has an adverse effect on the life of the equipment. More importantly, this intermittent operation is difficult to maintain stable reaction conditions, resulting in large quality fluctuations between different batches of products, and limits the improvement of 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.

[0034] The present application adopts a continuous production process instead of batch operation, reducing complex preparation work and subsequent processing 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, allowing 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 guaranteed. In addition, the new production method adopts a staged reaction strategy, including pre-hydrogenation, loop hydrogenation, and then post-hydrogenation. The reaction conditions are adjusted according to the needs of each stage to ensure that the ideal hydrogenation depth can be achieved even under high solid content conditions. At the same time, reasonable catalyst distribution and use further improve hydrogenation efficiency, so that efficient conversion rates can still be obtained even when there are more solids. These improvements work together to not only improve the mass transfer efficiency of the entire system, but also reduce the amount of solvent required to achieve the same reaction effect compared to the prior art, thereby allowing higher solid contents without affecting product performance and reaction effects, but also enhance material fluidity and solve problems such as common stirring difficulties or material accumulation at high solid contents.

[0035] In summary, the introduction of a continuous loop hydrogenation system, combined with optimized mixing mechanisms, enhanced mass transfer efficiency, and the reduction of unnecessary operating steps, overcomes many limitations of traditional processes and achieves the goal of increasing solids content from the traditional level to 20%. This advancement 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 widespread application.

[0036] One of the key advantages of the method provided in 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 bring beneficial effects. It improves production efficiency and resource utilization, reduces costs, more raw materials are converted into target products, reduces the formation of unnecessary by-products, makes the output polymer more in line with the expected performance requirements, and may reduce the need for subsequent processing steps. For catalysts, a low-temperature environment helps to extend their service life. Many catalysts lose their activity when exposed to high temperatures for a long time, and low-temperature operating conditions can slow down this process, thereby reducing the frequency and cost of replacing the catalyst while maintaining the stability and continuity of the production process. At the same time, lowering the reaction temperature means reducing the energy required to heat the reaction system, which is particularly important for large-scale industrial production. Lower operating temperatures also improve the safety of the process and reduce the potential risks caused by high temperatures.

[0037] This solution, through the effective combination of equipment and methods, not only addresses the complex operations, high hydrogen consumption, and inconsistent product quality between batches inherent in traditional kettle-type hydrogenation processes, but also improves production efficiency, reduces energy consumption, and enhances product quality consistency. Furthermore, this continuous production model offers a high degree of flexibility, enabling rapid response to changes in market demand, significantly enhancing production adaptability and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 Schematic diagram of the structure of the continuous loop hydrogenation system for preparing styrene-based elastomers.

[0039] 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 DESCRIPTION

[0040] The following specific examples further illustrate the technical solutions of the present invention and its effects. The following examples are only used to illustrate the content of the present invention and are not intended to limit the scope of protection of the present invention. Simple changes made to the present invention by applying the concept of the present invention are all within the scope of protection claimed in the present invention.

[0041] The equipment used in the preparation method of the present invention can be any known equipment in the art. Unless otherwise specified, the raw materials used in the present invention are commercially available.

[0042] Example 1

[0043] like Figure 1 As shown, the present application provides a continuous loop hydrogenation system for preparing styrene-based elastomers, comprising 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; the pre-hydrogenation reactor comprises a pre-hydrogenation reactor a1 and a pre-hydrogenation reactor b11; the delivery pump comprises 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 discharge port of the loop hydrogenation reactor 2 , and the other end is connected to the feed port of the loop hydrogenation reactor 2 .

[0044] First, in the pre-hydrogenation stage, the system is equipped with at least two pre-hydrogenation reactors, namely pre-hydrogenation reactor a1 and pre-hydrogenation reactor b11. The unhydrogenated elastomer solution raw material and initiator react with hydrogen for the first time in the pre-hydrogenation reactor a1. Afterwards, the material in the pre-hydrogenation reactor a1 is transported to the pre-hydrogenation reactor b11 by the pre-hydrogenation discharge pump a601, and a co-catalyst 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 by the pre-hydrogenation discharge pump b62. The loop hydrogenation reactor 2 is one of the key components of this system. It is not only provided with a venturi ejector 201 to increase the contact area of different phases, the main catalyst is added to the reactor in the form of a spray to improve the hydrogenation efficiency, but also equipped with a loop hydrogenation reactor pump 202. One end of this pump is connected to the discharge port of the loop hydrogenation reactor 2, and the other end is connected back to the feed port, forming a closed loop, so that the material can circulate in the reactor, promote full contact between the reactants, and thus enhance the reaction effect. The material that completes the loop hydrogenation reaction then enters the post-hydrogenation reactor 3, where the hydrogen dissolved in the material is used for further hydrogenation, which extends the hydrogenation reaction time and improves 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 eventually enters the blending tank 5 for further processing or direct use.

[0045] The method provided in this embodiment is as follows:

[0046] S1. A 20% mass concentration of styrene-butadiene-styrene block copolymer and cyclohexane mixed raw material solution and butyl lithium solution were added to the pre-hydrogenation reactor a1 and hydrogen was introduced for mixing; the butyl lithium solution solvent was cyclohexane, the mass concentration was 6%, the raw material flow rate was 15t / h, the initiator flow rate was 80L / h, the temperature was 75 degrees, the pressure was 0.4MPa, and the residence time was 1.5h.

[0047] S2. The reaction material in the pre-hydrogenation reactor a1 is then transported to the pre-hydrogenation reactor b11 through the pre-hydrogenation discharge pump a601, and co-catalysts dimethyl phthalate and methyl o-toluate are added for co-catalysis. The co-catalyst addition amount is 30L / h, the temperature is 75 degrees, the pressure is 0.4MPa, and the residence time is 0.4h.

[0048] S3 pre-hydrogenation reactor b11 in the reaction material is transported to the loop hydrogenation reactor 2 by the pre-hydrogenation discharge pump b62, the loop hydrogenation reactor 2 is fed with hydrogen and the main catalyst titanocene dichloride, the loop hydrogenation; the amount of catalyst added is 0.8% by mass of the reaction material, the loop circulation volume is 4000m 3 / h, hydrogenation temperature 100 degrees, hydrogenation pressure 1.7MPa, residence time 2h.

[0049] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor for post-hydrogenation reaction at a reaction temperature of 93 degrees, a pressure of 1.0 MPa, and a residence time of 0.6 h.

[0050] S5. The material in the post-hydrogenation reactor enters the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 80 degrees and the pressure is 0.1 MPa.

[0051] S6. The product separated from the gas-liquid separation tank 4 enters the blending tank 5, and the temperature of the blending tank 5 is 80 degrees and the pressure is normal.

[0052] Example 2

[0053] The continuous loop hydrogenation system for preparing styrene-based elastomers used in this embodiment is the same as that in Example 1, and the production method is as follows:

[0054] S1. A 15% mass concentration of styrene-butadiene-styrene block copolymer and cyclohexane mixed raw material solution and butyl lithium solution are added to the pre-hydrogenation reactor a1, and hydrogen is introduced for mixing; the butyl lithium solution solvent is cyclohexane, the mass concentration is 6%, the raw material flow rate is 15t / h, the initiator butyl lithium flow rate is 60L / h, the temperature is 70 degrees, the pressure is 0.2MPa, and the residence time is 1h.

[0055] S2. The reaction material in the pre-hydrogenation reactor a1 is then transported to the pre-hydrogenation reactor b11 through the pre-hydrogenation discharge pump a601, and co-catalysts dimethyl phthalate and methyl o-toluate are added for co-catalysis. The co-catalyst addition amount is 25L / h, the temperature is 80 degrees, the pressure is 0.2MPa, and the residence time is 0.6h.

[0056] S3 pre-hydrogenation reactor b11 in the reaction material is transported to the loop hydrogenation reactor 2 by the pre-hydrogenation discharge pump b62, the loop hydrogenation reactor 2 is fed with hydrogen and the main catalyst titanocene dichloride, the loop hydrogenation; the amount of catalyst added is 0.8% by mass of the reaction material, the loop circulation volume is 4000m 3 / h, hydrogenation temperature 90 degrees, hydrogenation pressure 1.5MPa, residence time 2h.

[0057] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor for post-hydrogenation reaction at a reaction temperature of 93 degrees, a pressure of 1.1 MPa, and a residence time of 0.3 h.

[0058] S5. The material in the post-hydrogenation reactor enters the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 90 degrees and the pressure is 0.1 MPa.

[0059] S6. The product separated from the gas-liquid separation tank 4 enters the blending tank 5, and the temperature of the blending tank 5 is 80 degrees and the pressure is normal.

[0060] Example 3

[0061] The continuous loop hydrogenation system for preparing styrene-based elastomers used in this embodiment is the same as that in Example 1, and the production method is as follows:

[0062] S1. A 20% mass concentration of styrene-butadiene-styrene block copolymer and cyclohexane mixed raw material solution and butyl lithium solution are added to the pre-hydrogenation reactor a1 and hydrogen is introduced for mixing; the butyl lithium solution solvent is cyclohexane, the mass concentration is 6%, the raw material flow rate is 15t / h, the initiator butyl lithium flow rate is 60L / h, the temperature is 90 degrees, the pressure is 0.6MPa, and the residence time is 2h.

[0063] S2. The reaction material in the pre-hydrogenation reactor a1 is then transported to the pre-hydrogenation reactor b11 through the pre-hydrogenation discharge pump a601, and co-catalysts dimethyl phthalate and methyl o-toluate are added for co-catalysis. The co-catalyst addition amount is 25L / h, the temperature is 90 degrees, the pressure is 0.2MPa, and the residence time is 0.6h.

[0064] S3 pre-hydrogenation reactor b11 in the reaction material is transported to the loop hydrogenation reactor 2 by the pre-hydrogenation discharge pump b62, the loop hydrogenation reactor 2 is fed with hydrogen and the main catalyst titanocene dichloride, the loop hydrogenation; the amount of catalyst added is 0.8% by mass of the reaction material, the loop circulation volume is 4000m 3 / h, hydrogenation temperature 105 degrees, hydrogenation pressure 1.9MPa, residence time 2h.

[0065] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor for post-hydrogenation reaction at a reaction temperature of 93 degrees, a pressure of 1.1 MPa, and a residence time of 0.3 h.

[0066] S5. The material in the post-hydrogenation reactor enters the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 90 degrees and the pressure is 0.1 MPa.

[0067] S6. The product separated from the gas-liquid separation tank 4 enters the blending tank 5, and the temperature of the blending tank 5 is 80 degrees and the pressure is normal.

[0068] Example 4

[0069] The present application provides a continuous loop hydrogenation system for preparing styrene-based elastomers, comprising 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; 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.

[0070] The production method is as follows:

[0071] S1. A 20% mass concentration of styrene-isoprene-styrene block copolymer mixed with cyclohexane and dimethyl phthalate was added to a pre-hydrogenation reactor and hydrogen was introduced for mixing; the feed flow rate was 15 t / h, the dimethyl phthalate flow rate was 30 L / h, the temperature was 75 degrees, the pressure was 0.4 MPa, and the residence time was 1.5 h.

[0072] S2. The reaction material in the pre-hydrogenation reactor is 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 amount of catalyst added is 0.8% by mass of the reaction material, and the loop circulation volume is 4000m 3 / h, hydrogenation temperature 90 degrees, hydrogenation pressure 1.7MPa, residence time 2h.

[0073] S4. The reaction materials in the loop hydrogenation reactor 2 enter the post-hydrogenation reactor for post-hydrogenation reaction at a reaction temperature of 93 degrees, a pressure of 1.0 MPa, and a residence time of 0.6 h.

[0074] S5. The material in the post-hydrogenation reactor enters the gas-liquid separation tank 4 for material separation. The temperature in the gas-liquid separation tank 4 is 80 degrees and the pressure is 0.1 MPa.

[0075] S6. The product separated from the gas-liquid separation tank 4 enters the blending tank 5, and the temperature of the blending tank 5 is 80 degrees and the pressure is normal.

Claims

1. A continuous loop hydrogenation system for preparing styrene-based elastomers, characterized by: 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; the delivery pump is arranged on the connecting pipeline of the pre-hydrogenation reactor and the loop hydrogenation reactor (2); the pre-hydrogenation reactor comprises at least 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) is arranged on the connecting pipeline of the pre-hydrogenation reactor a (1) and the pre-hydrogenation reactor b (11), and the pre-hydrogenation discharge pump b (62) is arranged on the connecting pipeline of the pre-hydrogenation reactor b (11) and the loop hydrogenation reactor (2).

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

3. The continuous loop hydrogenation system for preparing styrene-based elastomers according to claim 1, 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).

4. The continuous loop hydrogenation method for producing styrene-based elastomers according to claim 1, wherein: The following steps are involved: S1. Adding the unhydrogenated elastomer solution and the initiator to the pre-hydrogenation reactor a (1), introducing hydrogen to react; S2. The reaction material in the pre-hydrogenation reactor a (1) is transported to the pre-hydrogenation reactor b (11) through the pre-hydrogenation discharge pump a (601), and a co-catalyst 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) for 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).

5. The continuous loop hydrogenation method for producing styrene-based elastomers according to claim 4, characterized in that: The non-hydrogenated elastomer is a styrene-butadiene-styrene block copolymer.

6. The continuous loop hydrogenation method for producing styrene-based elastomers according to claim 4, characterized in that: The non-hydrogenated elastomer is a styrene-isoprene-styrene block copolymer.

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