A shell-and-tube reactor for succinic acid type polycarbonate polyether polyols

Abstract

This invention provides a tubular reactor for succinic acid-type polycarbonate polyether polyols, relating to the fields of polycarbonate polyether polyols and carbon dioxide chemicals. The tubular reactor is designed with specific premixing units, reaction units, and their structures and parameters. The premixing unit mixes all raw materials via carbon dioxide bubbling. The tubular reactor in the reaction unit has dispersion plates with specific shapes and openings. Through coordinated control of the device structure and process parameters, a one-time feeding production process for succinic acid-type polycarbonate polyether polyols is achieved, reducing process steps and shortening process time. This invention solves the problems of wide molecular weight distribution, significantly larger molecular weights than target values, and susceptibility to explosive polymerization in existing technologies for succinic acid-type polycarbonate polyether polyols. The succinic acid-type polycarbonate polyether polyols of this invention have a narrow molecular weight distribution, with a small difference between the actual product molecular weight and the target theoretical value. The production process is safe, does not produce explosive polymerization, has no scale-up effect, and is suitable for large-scale industrial production.

Description

Technical Field

[0001] This invention relates to the fields of polycarbonate polyether polyols and carbon dioxide chemicals, and specifically to a tubular reaction apparatus for succinic acid-type polycarbonate polyether polyols. Background Technology

[0002] Succinic acid-type polycarbonate polyether polyols are a class of polyols with carbonate groups within the molecule and hydroxyl groups at the ends of the molecular chain. One of their raw materials, carbon dioxide, is inexpensive, readily available, non-toxic, and non-flammable, exhibiting a clear carbon dioxide fixation effect. Furthermore, the reaction requires relatively low temperatures and energy consumption, making the carbon dioxide-epoxide-modified copolymerization method promising and possessing high industrial value. Polycarbonate polyether polyols simultaneously possess the high modulus, high hydrogen bond density, high weather resistance, and abrasion resistance inherent in carbonate bonds, and the flowability and flexibility provided by ether bonds. They are widely used in polyurethane applications, and polyurethane coatings, adhesives, and foams prepared from these polyols exhibit superior product performance. The market prospects for these polyols are broad, and their synthesis and industrial production have been extensively and deeply studied globally.

[0003] In the synthesis of succinic acid-based polycarbonate polyether polyols, bimetallic cyanide (DMC) catalysts are simple to prepare, low in cost, and produce products with residual heavy metals below 30 ppm, enabling highly active preparation of polycarbonate polyether polyols. However, the reaction of polycarbonate polyether polyols is exothermic, requiring the reaction system to prevent overheating. Excessive temperature leads to low carbonate chain segment content, a wider molecular weight distribution, and a higher proportion of cyclic carbonate byproducts, reducing product quality. Compared to the reaction system of polyether polyols, the reaction system of polycarbonate polyether polyols, in addition to the large amount of exothermic reaction generated by the epoxide-activated catalyst resulting in high temperature and pressure, also involves a large amount of CO2 gas feedstock, leading to even higher pressure in the reaction system. This places extremely stringent requirements on the temperature and pressure resistance of the reactor. Furthermore, improper or instantaneous activation of the DMC catalyst (due to excessively high epoxide concentration) can lead to explosive polymerization, easily causing high-temperature and high-pressure safety accidents (CN116874759A). In other words, if the epoxide raw material is added all at once before catalyst activation, it will cause instantaneous catalyst activation, highly likely leading to high-temperature and high-pressure safety accidents. Therefore, based on the characteristics of the above reaction system, on the one hand, to obtain polycarbonate polyether polyol products with the target molecular weight distribution, and on the other hand, to ensure production safety and avoid explosive polymerization and equipment safety hazards caused by excessive exothermic reactions, a one-step feeding process cannot be used. A two-step production process with batch feeding is necessary, which is cumbersome, time-consuming, and economically inefficient. The specific reasons are as follows: (1) Chinese patent CN115785435B clearly reports that the catalytic reaction mechanism of bimetallic complex (abbreviated as DMC) is divided into two steps: the induction activation period and the chain segment growth period. 1) Induction activation period: The epoxy compound activates DMC to generate a large number of active centers. This process is the induction activation stage. In order to quickly and completely activate DMC, an initial activation temperature is required, which should not be too high, for the breaking of chemical bonds. During the activation process, the epoxy compound will release a lot of heat due to polymerization, and the reaction controllability is poor. The temperature of the reaction system in this stage is the initial temperature + the temperature of the heat release increase, which is called the activation temperature. This temperature is one of the temperature peaks in the entire process and is related to the high pressure resistance of the equipment and the activity of the catalyst. 2) The chain segment growth step is after DMC is fully activated. The active centers are connected to many chains. The epoxy compound and CO2, as polymer monomers, insert into the vacancy provided by the active center to carry out ring-opening polymerization and realize the chain growth of the polymer. In this process, external heat is required to facilitate rapid chain growth. The temperature of this stage is called the polymerization reaction temperature. Based on the above reaction mechanism, it is known that an induction activation stage must be performed before the chain growth reaction stage to generate activation centers. Therefore, the existing synthesis process must be divided into two independent steps, corresponding to the induction activation period and the chain growth period, respectively. During the induction activation period, a catalyst is added before the reaction, and an appropriate amount of the first batch of epoxy compound is added to activate the catalyst and generate a large number of active centers. Once induction begins, the epoxy compound releases a large amount of heat, and high temperatures (>100℃) and high pressure (>4MPa) are generated in the reactor, resulting in poor reaction controllability and high requirements for process and equipment safety. The rapid drop in reactor pressure indicates that the catalyst is fully activated, which is considered the end of the induction activation period. This period is counted from the time when DMC comes into contact with the epoxy compound until the pressure drops sharply. During the chain growth period, after the induction activation period ends, the temperature in the reactor is observed to be >100℃. The second batch of epoxy compound and initiator are then slowly added to initiate chain growth.

[0004] (2) In the synthesis process of polycarbonate polyether polyols, the initiator can adjust the chain segment length of the polycarbonate polyether polyol, thereby narrowing the molecular weight distribution and obtaining the product with the target molecular weight. Chinese patent CN115785435B clearly reports that the order of adding the initiator will affect the overall reaction time and product weight. If the initiator is added before activation, it will reduce or eliminate the catalyst activity. For the active center of DMC, it will produce a "passivation" effect. The "passivation" effect means that the initiator covers the surface of DMC, reducing or eliminating the catalyst activity. Therefore, the initiator cannot be added together with the catalyst and epoxy compound. For most types of catalysts such as carboxylic acids and phenols, it is easy to passivate the catalytic active center and it is suitable to add it after activation.

[0005] (3) Succinic acid, as a commonly used initiator, has a melting point of 188℃ and decomposes at 235℃. As can be seen from the above mechanism, a large amount of heat is released during the induction activation period, making it one of the temperature peaks of the entire process. The more epoxy compound added, the more severe the heat release and the higher the system temperature. Therefore, the existing technology adopts a batch feeding method of adding propylene oxide to prevent the initiator from decomposing at high temperatures during the induction activation period. If a one-time feeding method is adopted, especially in industrial-scale production, the huge instantaneous heat release will cause the system temperature to soar, causing the succinic acid initiator to decompose, and the initiator will lose its function; in addition, it will also bring safety hazards to the equipment under high temperature and high pressure.

[0006] Based on existing succinic acid-based polycarbonate polyether polyol production processes, reactors for industrial production can be categorized into batch reactors and tubular reactors. Batch reactors suffer from several drawbacks: larger diameters lead to uneven mixing and poor overall mixing; varying energy levels at different reaction stages hinder operation and control; larger reactors have smaller surface areas, resulting in lower heat transfer efficiency and difficulty in temperature control, especially during rapid and exothermic reactions where heat cannot be removed promptly, increasing the risk of safety issues; and prolonged material retention time within the reactor increases the likelihood of side reactions (CN109225114A). These issues are particularly detrimental to the synthesis of succinic acid-based polycarbonate polyether polyols catalyzed by DMC. In contrast, tubular reactors offer more controllable pressure and temperature during the reaction process, resulting in higher monomer conversion efficiency (Encyclopedia of Materials: Science and Technology (Second Edition) 2001, 7181-7184). Therefore, they have attracted widespread attention in the industrial production of polycarbonate polyether polyols. Because tubular reactors have a small cross-sectional area and low capacity, industrial production requires the arrangement of pipe arrays to form a shell-and-tube reactor. This typically necessitates the installation of a circulating pump to ensure the reaction materials circulate, promoting uniform reaction, rapid heat transfer, and reducing side reactions. Existing shell-and-tube reactors using a batch feeding process also operate on the aforementioned two-step reaction mechanism: a portion of propylene oxide is first introduced for activation, followed by continuous feeding, reaction, and discharge.

[0007] Existing technologies do not report a single-feed process for polycarbonate polyether polyols. Even if existing technologies report processes for producing polyether polyols using a single-feed method, the characteristics and reaction states of the reaction process are completely different due to variations in the prepared products, reaction equipment, and overall process. Therefore, even if similar feeding processes are reported in existing technologies, they cannot be directly applied. For example, although Chinese patent CN103687894A adds epoxide, CO2, and initiator before the reaction, a portion of the epoxide is added to activate the catalyst first, representing a separate activation step, rather than adding all the raw materials at once. While Chinese patent CN106471042B introduces all the raw materials into the reactor before the reaction, the raw materials are introduced over a certain time interval, not in a single-feed process. Furthermore, the equipment used in this process is a tubular reactor, not a shell-and-tube reactor. Moreover, in the reaction for preparing polycarbonate polyether polyols using succinic acid as an initiator, due to the specific characteristics of the raw materials and reaction, conventional shell-and-tube reactors are not applicable. Specifically: Unlike the reaction of polyether polyols, in the reaction of polycarbonate polyether polyols, in addition to using a circulating pump to circulate and evenly disperse the reactants into each tube, the succinic acid initiator solid dissolves in the epoxy compound and enters the reaction unit during feeding. At the same time, carbon dioxide gas is continuously introduced as a raw material at another feed port. Therefore, in the reaction unit of the tube reactor, there must be a process of gas-liquid-solid mixing between the introduced carbon dioxide gas and the reactants such as catalyst, epoxy compound, and initiator dispersed in each tube. This area can be called the gas-liquid mass transfer zone. After the initial mixing in the gas-liquid mass transfer zone, the reactants will enter the reaction pipeline to continue the circulating reaction. However, in existing tubular reactors, when the reactants are dispersed into the individual tubes via a circulating pump, the material is dispersed into droplets after passing through the dispersion plates. Inevitably, some reactants splash onto the tube walls. Since the tube wall temperature is as high as 70-80°C, while the boiling point of epoxy compounds such as propylene oxide is only 34°C, the propylene oxide containing the initiator evaporates instantly upon contact with the tube wall, while the initiator succinic acid solid is precipitated and remains on the tube wall. Because succinic acid has low solubility in propylene oxide, even if the epoxy compounds are subsequently dispersed into the tubes, the continuously introduced carbon dioxide gas cooling process prevents the droplets from quickly dissolving the succinic acid on the tube wall. Ultimately, this leads to a situation where the initiator, catalyst, and propylene oxide in the polymerization reaction system become entangled in the reaction. An imbalance in the ratio of catalyst and carbon dioxide, due to a decrease in the proportion of succinic acid, means that the catalyst is in excess, accelerating the consumption of carbon dioxide. This further accelerates the polymerization reaction, resulting in a significantly larger molecular weight than the theoretical value, making it impossible to obtain the target product, and even ultimately leading to explosive polymerization and causing production accidents. Even if the droplet-like material washes some of the succinic acid precipitated on the pipe wall into the reaction system, the undissolved solid succinic acid entering the reaction system cannot be evenly distributed due to the high viscosity of the product. This leads to excessively rapid chain segment growth in areas with high initiation dosage, resulting in rapid molecular weight growth and even local explosive polymerization of the product. Rapidly initiating the reaction in areas with high initiation dosage results in a large number of chain segments with small molecular weights, leading to an overall product with an excessively wide molecular weight distribution and poor product quality.

[0008] In summary, existing technologies, based on the reaction mechanism, require a two-step production process with batch feeding to obtain polycarbonate polyether polyols with the target molecular weight while ensuring production safety and avoiding explosive polymerization and equipment safety hazards caused by excessive exothermic reactions. This process is cumbersome, time-consuming, and economically inefficient. Although a few existing technologies report one-step feeding processes for polycarbonate polyether polyols, these processes do not use tubular reactors. Furthermore, due to the specific characteristics of the raw materials and reaction in the preparation of polycarbonate polyether polyols using succinic acid as an initiator, conventional tubular reactors are not suitable. Using conventional tubular reactors to produce succinic acid-type polycarbonate polyether polyols results in problems such as a wide molecular weight distribution, a molecular weight significantly larger than the target value, and a tendency for explosive polymerization. Additionally, the poor controllability of the one-step feeding process and its poor compatibility with existing reactors lead to poor batch-to-batch stability. Therefore, existing technologies do not provide a suitable one-step feeding process for the industrial production of succinic acid-type polycarbonate polyether polyols, nor a suitable tubular reactor to solve these problems. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a tubular reactor for succinic acid-type polycarbonate polyether polyols, relating to the fields of polycarbonate polyether polyols and carbon dioxide chemicals. This invention designs a dedicated tubular reactor for succinic acid-type polycarbonate polyether polyols, employing a one-time feeding process to reduce process steps and shorten process time. The one-time feeding refers to adding the epoxide compound, catalyst, and initiator into the reactor all at once, without adding these three raw materials during the reaction process. This one-time feeding process is achieved through the specific premixing unit and reaction unit structural design and parameters within the tubular reactor. Process parameters such as the premixing method and corresponding specific tubular reactor configurations are used to achieve this process. The synergistic effect of multiple features of the tubular reactor, such as the structure shape of the dispersion sheet, pore distribution characteristics, and open area ratio, solves the problems of wide molecular weight distribution, significantly larger molecular weight than the target value, and easy explosive polymerization of succinic acid-type polycarbonate polyether polyols in the prior art. The molecular weight distribution coefficient (PDI) of the succinic acid-type polycarbonate polyether polyol of the present invention is ≤1.2; the molecular weight difference index (ΔM) is <2%; the batch stability coefficient (Q) is <15, and even better, Q ≤10. The molecular weight distribution of the succinic acid-type polycarbonate polyether polyol of the present invention is narrow, the difference between the actual product molecular weight and the target theoretical value is small, the molecular weight of the product is stable in different batches, the production process is safe, there is no explosive polymerization, no scale-up effect, and it is suitable for large-scale industrial production.

[0010] The technical solution of the present invention is as follows: The present invention provides a tubular reaction apparatus for succinic acid type polycarbonate polyether polyol, the tubular reaction apparatus comprising a premixing unit (001) and a reaction unit (002). The premixing unit is used to fully mix carbon dioxide with epoxy compound, succinic acid and DMC catalyst in a bubbling manner to obtain a premix. The premix is ​​fed into the reaction unit (002) in one go. The reaction unit (002) includes at least one tubular reactor (022). The tubular reactor (022) includes a dispersion plate (222) and a reaction pipe (223). The reaction pipe (223) includes a gas-liquid mixing heat conduction zone (2231) and a solid-liquid mixing zone (2232). The flow direction of the premix is ​​through the gas-liquid mixing heat conduction zone (2231) to the solid-liquid mixing zone (2232), and then back to the gas-liquid mixing heat conduction zone (2231) to complete the cycle. The dispersing plate (222) is used to control the flow rate and direction of materials in the reaction system, dispersing and controlling the materials in the gas-liquid mixing heat conduction zone (2231) so that they can be dispersed into liquid droplets for mass and heat transfer without contacting the pipe wall; the structure of the dispersing plate (222) is a circular porous structure, and the holes are equilateral triangular holes. Two adjacent triangular holes are centrally symmetrical in the same horizontal direction, and two adjacent triangular holes are axially symmetrical in the same direction perpendicular to the horizontal direction; the porosity of the dispersing plate (222) is 40%-60%; The solid-liquid mixing zone (2232) is used to realize the real-time mixing and polymerization reaction of DMC catalyst and epoxy compound; The tubular reactor (022) is also used to introduce supplemental pressurized carbon dioxide, which is introduced in the opposite direction to the flow direction of the premix, to obtain the succinic acid type polycarbonate polyether polyol through a polymerization reaction.

[0011] The general reaction formula is shown in Formula 3: Formula 3, The tubular reactor of this invention uses a premixing unit to uniformly mix the raw materials and then feed them into the reaction unit in one go. Combined with parameter settings in the tubular reactor, this achieves a one-time feeding production process for succinic acid-type polycarbonate polyether polyols. Unexpectedly, this results in a narrow molecular weight distribution of the prepared succinic acid-type polycarbonate polyether polyol, with a small difference between the actual product molecular weight and the target theoretical value. The production process is safe, without explosive polymerization or scale-up effects. Specifically, in the tubular reactor of this invention, the epoxy compound, DMC catalyst, and initiator are first thoroughly mixed at 30-40°C in the premixing unit using continuous carbon dioxide bubbling. This ensures high solubility of succinic acid while inhibiting premature reaction, providing a certain amount of initial carbon dioxide for the formal reaction. Premixing in a low-temperature, continuously bubbling carbon dioxide atmosphere allows the initiator and DMC to move dynamically at low temperature, reducing the initiator's encapsulation of the DMC catalyst and preventing passivation of the catalyst's active sites. In the reaction unit, the tubular reactor uses a specific dispersion sheet structure combined with the material flow rate of the process. While maintaining the dispersion of the material, it allows the material to fall as large liquid droplets without splashing onto the tube wall, ensuring gas-liquid mass transfer and reducing the evaporation of propylene oxide on the tube wall in the gas-liquid mixing heat conduction zone. This increases the ability of subsequent propylene oxide to flush down any solid materials that may precipitate. The gas-liquid mixing heat conduction zone of this invention allows the material to reabsorb carbon dioxide and release the heat of generation without causing excessive atomization of the material, which would lead to evaporation and precipitation of solids on the tube wall and cause material imbalance. While consuming carbon dioxide, it replenishes low-temperature carbon dioxide to 3MPa, making this area a lower temperature zone, allowing for better release of the heat of generation and reducing the decomposition of succinic acid initiator caused by the high temperature of the reaction heat. The solid-liquid mixing zone allows the catalyst to be fully and evenly mixed when the material flows in the reactor, allowing the temperature of the tube wall to be better conducted to the interior, and allowing the heat of generation during the reaction to be dispersed in time, making it less likely to generate explosive agglomeration points.

[0012] In one embodiment, the DMC catalyst in Formula 3 is a mixed acid-modified zinc-cobalt bimetallic cyanide catalyst, wherein the catalyst contains only zinc and cobalt as metal elements, excluding impurities; the catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent, wherein the water-soluble metal salt of cobalt is a cobalt cyanide salt; the catalyst is synthesized by modification with a mixed acid, wherein the mixed acid comprises at least one organic acid and at least one water-soluble inorganic acid, wherein: The water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and the pH value is between 0 and 5; The organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and butanetetracarboxylic acid, and the molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:1.

[0013] In one embodiment, the reaction temperature of the solid-liquid mixing zone (2232) increases in a gradient along the direction of material flow, and the temperature difference between the material at one end and the material at the other end does not exceed 10°C. In one embodiment, the ratio of the diameter of the dispersion sheet (222) to the inner diameter of the reaction pipe (223) is 1:1; In one embodiment, the dispersion sheet (222) is located 10 to 50 mm from the top of the reaction conduit (223); In one embodiment, the reaction pressure of the reaction unit (002) is 3-4 MPa; more preferably, the reaction pressure is 3 MPa; when the pressure is too low, carbon dioxide is automatically introduced by a solenoid valve to replenish the pressure; that is, carbon dioxide is introduced from the carbon dioxide inlet (226) at the bottom of the reaction pipeline to form convection with the material to continue heat exchange and increase the carbon dioxide content in the material. In one embodiment, the total volume of the material accounts for 0 < V of each reaction pipe (223). 物料 ≤80%, more preferably 50-80%; preferably, the volume of the gas-liquid mixing heat conduction zone (2231) accounts for 20% ≤ V of each reaction pipe (223). 气液混合热传导区 <100%, more preferably 20%-50%.

[0014] In one embodiment, the ratio of the epoxy compound to succinic acid is propylene oxide: succinic acid = 15:1 to 70:1, and the DMC catalyst is 500 ppm.

[0015] In one embodiment, the premixing temperature of the premixing unit (001) is 30-40°C; more preferably, the premixing temperature is 40°C. In one embodiment, the premixing time is 1-2 hours; more preferably, the premixing time is 1 hour. In one embodiment, CO2 is slowly bubbled in the premixing unit (001), and the pressure in the premixing unit (001) does not exceed 1 MPa; more preferably, the premixing pressure is 0.1-0.5 MPa; even more preferably, the premixing pressure is 0.4 MPa. In one embodiment, the temperature of the carbon dioxide in the premixing unit (001) is 40°C, and the bubbling speed is 40-60 bubbles / min.

[0016] In one embodiment, the reaction temperature of the solid-liquid mixing zone (2232) is 70-90°C; more preferably, the reaction temperature is 80°C. In one embodiment, the reaction pressure of the solid-liquid mixing zone (2232) is 3-4 MPa; more preferably, the reaction pressure is 3 MPa. In one embodiment, the reaction time of the solid-liquid mixing zone (2232) is defined as the reaction endpoint when the density reaches 1.12 g / cm³. 3 The reaction is terminated at that time.

[0017] In one embodiment, the reaction unit (002) of the tubular reactor is composed of one or more tubular reactors (022) connected in parallel, wherein each tubular reactor (022) has the same liquid circulation path with the connecting pipe (228) and the circulating pump (021).

[0018] The present invention also provides a succinic acid-type polycarbonate polyether polyol prepared by the tubular reaction apparatus described above, wherein the structural formula of the succinic acid-type polycarbonate polyether polyol is shown in Formula 1: Formula 1, In Formula 1, R1 and R2 are hydroxyl groups or have the structure shown in Formula 2, but R1 and R2 are not all hydroxyl groups. Formula 2, In Equation 2, 0.1 < m / m+n < 0.9, 0.1 < n / m+n < 0.9, and m and n are both positive integers; The molecular weight Mn of the succinic acid type polycarbonate polyether polyol is 800-4200; The molecular weight distribution coefficient (PDI) of the succinic acid type polycarbonate polyether polyol is ≤2. The molecular weight difference index ΔM of the succinic acid type polycarbonate polyether polyol is <2%; preferably, the molecular weight difference index ΔM ≤1%. The molecular weight difference index is used to characterize the difference between the theoretical molecular weight of the product calculated according to the feed ratio and the actual molecular weight of the product obtained after the reaction. The smaller the molecular weight difference index, the smaller the difference between the actual product molecular weight and the theoretical molecular weight, indicating better controllability of the production equipment and process, higher yield of the target product, and higher product quality. The molecular weight difference index ΔM can be calculated using the following formula: ΔM=|g 实际 -g 理论 | / g 理论 100% Among them, g 实际 The number-average molecular weight of the product, in g. 理论 The theoretical molecular weight is calculated as follows: g 理论 =A B+D Where A is the average linker molecular weight, calculated as follows: A=X 102+Y 58 Where X represents the proportion of ester chains in the product, and Y represents the proportion of ether chains in the product.

[0019] Where B is the number of chain links, calculated as follows: B=K C (1-Z) Where K is the initiator molar ratio, C is the conversion rate, and Z is the mass percentage of polypropylene carbonate.

[0020] The conversion rate C is calculated as follows: C=M 反应po / M 投料po Where M 反应po The quality of the actual completed PO conversion is calculated as follows: M 反应po =(M 产物 -M 引发剂投料 ) n po Where n po The mass percentage of po in the product is calculated as follows: n po =58(X1+Y1+Z1) / 44 (X1+Z1)+58(X1+Y1+Z1) Where X1 is the NMR integral of the carbonate linkage, Y1 is the integral of the ether linkage, and Z1 is the polypropylene carbonate integral.

[0021] Where D represents the molecular weight of the initiator.

[0022] The batch stability coefficient of the succinic acid type polycarbonate polyether polyol is Q < 15, preferably Q ≤ 10; The formula for calculating the batch stability coefficient Q is as follows: Q=E H Where E is the volatility coefficient, which is calculated as follows: E=(g 最大 -g 最小 ) / g 理论中值 Where g 理论中值 This refers to the theoretical value (g) across all batches tested. 理论1、 g 理论2 ...g 理论n The median of the difference, H, is the average difference, which is calculated as follows: H = √(1 / n(g1-g)) 理论1 ) 2 +(g2-g 理论2) 2 +(g3-g 理论3 ) 2 +...(g) n -g 理论n ) 2 )) Where g 最大 Maximum molecular weight among all batches, g 最小 The minimum molecular weight for all batches, g1, g2, g3...g n The values ​​represent the molecular weight for each batch.

[0023] As can be seen from the above technical solution, the beneficial effects of the present invention are as follows: (1) The succinic acid type polycarbonate polyether polyol of the present invention has a narrow molecular weight distribution and the actual product molecular weight is small compared with the target theoretical value. This solves the problems of wide molecular weight distribution, significantly larger molecular weight than the target value, and easy explosive polymerization of the succinic acid type polycarbonate polyether polyol in the prior art. The molecular weight distribution coefficient PDI of the succinic acid type polycarbonate polyether polyol of the present invention is ≤1.2, the molecular weight difference index ΔM is <2%, more preferably ΔM is ≤1%, and the batch stability coefficient Q is <15, preferably Q is ≤10.

[0024] (2) This invention realizes a one-time feeding production process for succinic acid polycarbonate polyether polyols through a one-time feeding process and the structural features and parameters of a specific tubular reaction device designed for succinic acid polycarbonate polyether polyols. Through the synergistic effect of process parameters such as premixing method and corresponding specific tubular reaction devices such as dispersion sheet structure shape, pore distribution characteristics, and open porosity, the problem of wide molecular weight distribution, significantly larger molecular weight than target value, and easy explosive polymerization of succinic acid polycarbonate polyether polyols in the prior art is solved. Compared with traditional processes and reactors, the reaction steps are reduced, the reaction time is greatly shortened, the molecular weight of the product is highly controllable, the production is stable between batches, and the product quality is high. At the same time, the production process is safe, does not produce explosive polymerization, has no scale-up effect, and is suitable for large-scale industrial production. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall reaction device for succinic acid type polycarbonate polyether polyol. The green arrows represent the flow of carbon dioxide gas, the black arrows represent the flow of raw material propylene oxide, the blue arrows represent the flow of reactants circulating in the reaction unit, and the purple arrows represent the flow of products after the reaction is completed.

[0026] Figure 2 This is a side view of a tubular reactor for succinic acid-type polycarbonate polyether polyols. The green arrows represent the flow direction of supplemental carbon dioxide gas, and the blue arrows represent the flow direction of the reactants circulating in the reaction unit.

[0027] Figure 3 This is a schematic diagram of a sub-unit (i.e., reaction pipeline) of a succinic acid type polycarbonate polyether polyol tubular reactor.

[0028] Figure 4 This is a top view schematic diagram of two parallel configurations of a succinic acid-type polycarbonate polyether polyol tubular reactor. Figure 4 Image (a) is a top view of a tubular reactor with eight reaction pipes connected in parallel. Figure 4 (b) is a top view of a tubular reactor with four reaction pipes connected in parallel.

[0029] Figure 5 This is a schematic diagram of a sub-unit (i.e., a dispersion sheet) of a succinic acid type polycarbonate polyether polyol tubular reactor.

[0030] In the diagram: 001, Premixing unit; 002, Reaction unit; 003, Separation unit; 004, Refining unit; 005, Distillation unit; 006, Filling unit; Y1, Carbon dioxide; Y2, Succinic acid; Y3, DMC catalyst; Y4, Propylene oxide; Y5, Refining agent; 011, Carbon dioxide purifier; 012, Propylene oxide purifier; 013, Metering pump; 014, Premixer; 021, Circulation pump; 022, Tubular reactor; 023, Liquid distributor; 221, Feed inlet; 222, Dispersion plate; 223, Reaction pipeline; 224, Heat transfer jacket; 225, Static mixer; 226, Carbon dioxide refueling port; 227, Discharge port; 228, Connecting pipeline; 2231, Gas-liquid mixing heat conduction zone ( Figure 3 (Green area in the diagram); 2232, Solid-liquid mixing zone ( Figure 3 (Blue area in the diagram). Detailed Implementation

[0031] In the description of this invention, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "parallel", "inner", "outer", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0032] The DMC catalyst described in the embodiments and comparative examples of this invention is a mixed acid-modified zinc-cobalt bimetallic cyanide catalyst; the specific preparation is as follows: i) At least one water-soluble zinc salt and at least one water-soluble cobalt salt, wherein the water-soluble cobalt salt is a cyanide salt of cobalt, are reacted in an aqueous solvent in the presence of a mixed acid, wherein the mixed acid comprises at least one organic acid and at least one water-soluble inorganic acid, wherein: the water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and the pH value is between 0 and 5; the organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and butanetetracarboxylic acid; the molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:1; ii) The catalyst obtained in step i) is separated, washed and dried multiple times until the pH of the washing solution is 6-7 to obtain a mixed acid modified zinc-cobalt bimetallic cyanide catalyst.

[0033] The process of realizing the one-time feeding production process of the succinic acid type polycarbonate polyether polyol in the tubular reactor of the present invention includes the following steps: (1) Carbon dioxide (Y1) is passed through carbon dioxide purifier (011) and introduced into premixer (014). Propylene oxide raw material (Y4) is purified by propylene oxide purifier (012) and enters premixer (014) in carbon dioxide atmosphere through metering pump (013). A fixed amount of succinic acid (Y2) and catalyst (Y3) are added to the premixer (014) using a weighing hopper. The premixing temperature range is 30-40℃, the pressure range is ≤1MPa, and the premixing time is 1-2 hours. After the premixing is completed, the premixed material is fed into the reaction unit (002) at once.

[0034] (2) The premixed material is fed into the reaction unit (002) at once through the feed inlet (221), and then enters one or more tubular reactors (022) through the connecting pipe (228) and the liquid distributor (023). The tubular reactor (022) includes a dispersion plate (222), a reaction pipe (223), a heat transfer jacket (224), a static mixer (225), a carbon dioxide injection port (226), and a discharge port (227). The heat transfer jacket surrounds the outside of the reaction pipe (223). The heat jacket contains a heat transfer medium for heating or cooling the material in the reaction pipe (223). When the reactants enter the reaction pipe (223), the temperature of the reaction pipe (223) is controlled at 40°C and the carbon dioxide pressure is 0.1-2 MPa. After the reactants have completely entered, carbon dioxide is added through the carbon dioxide inlet (226) to make the pressure inside the reaction pipe (223) 3-4 MPa. When the reaction unit includes multiple tubular reactors (022), their arrangement is shown in the schematic diagram below. Figure 4As shown, but not limited to this arrangement; (3) Turn on the circulation pump (021) and control the temperature in the reaction pipeline (223) to 70-90℃. The raw material passes through the gas-liquid mixing heat conduction zone (2231) and the solid-liquid mixing zone (2232). The reaction pipeline (223), its solid-liquid mixing zone (2232), the static mixer (225), and the circulation pump (021) work together to disperse the mixed materials and high-temperature points during the reaction process. That is, the solid-liquid mixing zone (2232) makes the solid catalyst uniformly dispersed in the epoxy compound, and at the same time disperses the generated reaction heat, reducing the central temperature in the pipeline and The temperature difference of the pipe wall; the gas-liquid mixing heat conduction zone (2231), together with the dispersion plate (222) and the circulation pump (021), plays an efficient mass and heat transfer role, that is, in the gas-liquid mixing heat conduction zone (2231), the mixture with low CO2 content in the reaction pipe (223) is redissolved with CO2, so that there is a continuous sufficient CO2 to participate in the reaction, and at the same time, heat exchange occurs in the gas-liquid mixing heat conduction zone (2231). The specific process is as follows: the synthesis product in the reaction pipe (223) generates reaction heat, and the reaction heat is conducted to the CO2 gas in the gas-liquid mixing heat conduction zone, and the reaction... After the CO2 is consumed, the CO2 replenishment port (226) replenishes CO2 to keep the pressure inside the reaction pipe (223) constant. The newly added CO2 is directly replenished from the bottom and forms convection with the material to continue heat exchange, which plays a role in heat release. At the same time, it increases the carbon dioxide content in the material reacting at the bottom of the pipe, ensuring that there will be no situation where more polyether products are generated due to the decrease in carbon dioxide content in all reaction pipes during the synthesis process. Furthermore, the mixing of reactants and the release of reaction heat through the solid-liquid mixing zone and the gas-liquid mixing heat conduction zone further reduce the molecular weight distribution. The reaction mixture containing polycarbonate polyether polyol and propylene carbonate flows through a connecting pipe (228) located on the other side of the feed end of the reaction pipe (223). It then passes through a circulation pump (021) located at the confluence of the connecting pipe (228), and converges at a liquid distributor (023) at the top of the reaction pipe (223). After passing through the solid-liquid mixing zone (2232) and the gas-liquid mixing heat conduction zone (2231), a cycle is completed. The circulation flow rate is controlled to complete one cycle in 1-20 minutes. The density sensor data is observed, and when the density reaches 1.12 g / cm³... 3 The reaction is considered complete when the material flows out through the outlet (227), and the feed inlet (221) at a time shall not exceed 80% of the volume of the reaction pipe (223). (4) The outflowing mixture containing polycarbonate polyether polyol, cyclic carbonate and unreacted raw material propylene oxide is fed into the separation unit (003) of the post-processing zone. The separation unit (003) separates the propylene oxide and dissolved CO2 in the mixture to obtain a crude product, and adjusts the viscosity of the crude product. The crude product is fed into the refining unit (004), and a refining agent (Y5) is added for adsorption treatment. After filtration, a crude product with a catalyst metal content of less than 5 ppm is obtained. The refined crude product is fed into the distillation unit (005) to separate the main product polycarbonate polyether polyol and the by-product cyclic carbonate, thereby obtaining the polycarbonate polyether polyol product for filling in the filling unit (006).

[0035] The specific implementation of the present invention will be further described below. The parameters of different reaction devices are shown in Table 1.

[0036] Table 1. Parameters of the succinic acid type polycarbonate polyether polyol reaction apparatus Example 1 8L of propylene oxide was purified, and then added to a premixer along with 4g of DMC catalyst and 409g of succinic acid via a metering pump. After introducing carbon dioxide at 0.4MPa, the mixture was stirred at 40°C for 1 hour. The premix was then pumped into an 8L... In the reaction unit consisting of two tubular reactors, the diameter of each tubular reactor's reaction pipe is 100 mm and its length is 1000 mm. After all the pipes are filled, carbon dioxide is introduced into the reaction pipes to a pressure of 3 MPa and maintained at this pressure. The circulation pump is started, and the flow rate is controlled at 600 g / min. After reacting at 80°C for 3 hours, the density uniformly increases to 1.12 g / cm³. 3 The reaction stabilizes, at which point it ends, and the product is cooled and removed. After removing the catalyst using a catalyst filtration device, a scraped evaporator is used to separate the main and byproducts.

[0037] The crude product after catalyst removal was sampled and analyzed. Specifically, the crude product was collected in a container, and the polymerization product stream sample was characterized by 1H NMR spectroscopy to calculate the ratio of polymer to cyclic small molecules in the crude product. After the polymer was purified, 1H NMR spectroscopy was performed again to calculate the ratio of polycarbonate segments to polyether segments on the polymer backbone. The polymer backbone has only two structures, polycarbonate segments and polyether segments, and the sum of their percentages is 100%.

[0038] With the help of 1The amount of carbon dioxide introduced into the polycarbonate polyether polyol (carbonate repeatr content) and the ratio of propylene carbonate (cyclic carbonate) to polycarbonate polyether polyol were determined by ¹H-NMR (Bruker, DPX400, 400 MHz; pulse program zg30, waiting time d1:10 s, 64 scans). In all cases, the sample was dissolved in deuterated chloroform. 1 The relevant resonances in H-NMR (based on TMS=0ppm) are as follows: The peaks at 5.0 ppm and 4.2 ppm belong to the proton peaks on the methylene and methine groups of polycarbonate chains; 4.9 ppm, 4.5 ppm, and 4.1 ppm belong to the proton peaks on the methylene and methine groups of five-membered ring carbonates; and 3.5-3.8 ppm belong to the proton peaks on the ether chains. The integrated area of ​​the peak at a given ppm on the 1H NMR spectrum is represented by the capital letter A followed by a numerical subscript. A is an abbreviation for Area. For example, A... 5.0 This represents the integrated area of ​​the peak at 5.0 ppm. Based on the crude copolymer product... 1 H-NMR spectrum and the integrated area of ​​related proton peaks, the proportion of carbonate repeating units (molar ratio) in the copolymerization reaction (F CO2 ) and cyclic carbonate content (w / w) PC ), the amount of carbon dioxide inserted (M CO2 The calculation method for ) is as follows: in, F CO2 =(A 5.0 +A 4.2 -2×A 4.6 ) / [(A 5.0 +A 4.2 -2×A 4.6 )+A 3.5 ×100%; W PC =102×A 1.5 / [102×(A 5.0 +A 4.2 -2×A 4.6 +A1.5)+58×A 3.5 ×100%; M CO2 =44×F CO2 / [102×F CO2 +58×(1-F CO2 )]×100%; Coefficient 44 represents the molar mass of carbon dioxide, coefficient 58 represents the molar mass of PO, and coefficient 102 represents the sum of the molar masses of carbon dioxide (44 g / mol) and PO (58 g / mol).

[0039] The conversion rate of PO (propylene oxide) involves removing the product after cooling, separating unreacted propylene oxide through a primary separation unit, and calculating the actual conversion rate. The formula is n = m × (1 - M). CO2 ) / (Mm×M CO2 ); where m is the mass of the product after removing propylene oxide, and M is the total sample containing propylene oxide.

[0040] The number-average molecular weight (Mn) and the polydispersity index (PDI) of the polymer were determined by gel permeation chromatography (GPC).

[0041] The molecular weight difference index ΔM can be calculated using the following formula: ΔM=|g 实际 -g 理论 | / g 理论 100% Among them, g 实际 The molecular weight of the product, in g, represents the measured data. 理论 The theoretical molecular weight is calculated as follows: g 理论 =A B+D Where A is the average linker molecular weight, calculated as follows: A=X 102+Y 58 Where X represents the proportion of ester chains in the product, and Y represents the proportion of ether chains in the product.

[0042] Where B is the number of chain links, calculated as follows: B=K C (1-Z) Where K is the initiator molar ratio, C is the conversion rate, and Z is the mass percentage of polypropylene carbonate.

[0043] The conversion rate C is calculated as follows: C=M 反应po / M 投料po Where M 反应po The quality of the actual completed PO conversion is calculated as follows: M 反应po =(M 产物 -M 引发剂投料 ) n po Where n po The mass percentage of po in the product is calculated as follows: npo =58(X1+Y1+Z1) / 44 (X1+Z1)+58(X1+Y1+Z1) Where X1 is the NMR integral of the carbonate linkage, Y1 is the integral of the ether linkage, and Z1 is the polypropylene carbonate integral.

[0044] Where D represents the molecular weight of the initiator.

[0045] g 理论 Calculation example (taking Example 1 as an example): g-theory = A B+D A=0.58 102 + 0.42 58 = 83.52 B=33 / 1 0.97 (1-0.29)=22.7271 D=118 Therefore, the g-theory for Example 1 is 2016.167392; Examples 2-14 follow the preparation and testing methods of Example 1. Material parameters and process parameters are shown in Tables 2 and 3, and performance test results are shown in Table 4.

[0046] Table 2. Input Material Parameters for Succinic Acid-Based Polycarbonate Polyether Polyols Table 3. Process parameters for the polymerization reaction of succinic acid type polycarbonate polyether polyols. Table 4 Performance parameters of succinic acid type polycarbonate polyether polyols in Examples 1-14 Example 2 increased the volume percentage of CO2 and decreased the volume percentage of materials in the reaction pipe, i.e., increased the gas-liquid mixing heat conduction zone. It was observed that the product molecular weight, molecular weight distribution, and ester-ether ratio did not change significantly. Examples 3 and 4 scaled up the reaction in terms of the reaction pipe diameter. Examples 5 and 6 used different aspect ratios. Compared to Example 1, Examples 7 and 8 scaled up the reaction in a tubular reactor. Based on the reaction process and product results, when scaling up the reaction, only adding parallel tubular reactors and increasing the circulation pump flow rate is needed; no other adjustments are required. The polymer molecular weight, molecular weight distribution, and conversion rate did not fluctuate significantly. The molecular weight difference index was small and the molecular weight distribution was narrow, indicating that this production method has no scale-up effect and is suitable for industrial production. Data from Examples 9 and 10, compared to Example 1, show that this synthesis method can stably synthesize the product at 70-90℃. Data from Examples 11 and 12, compared with those from Example 1, show that when producing products with molecular weights of 1000-4000, the actual molecular weight of the product basically matches the theoretical value, and the molecular weight difference index between the actual and theoretical molecular weights is small. This indicates that the production equipment and process of the present invention are highly controllable, and the product quality is high. Examples 13 and 14 used dispersion sheets with different open-cell ratios. The results show that within the open-cell ratio range set by the present invention, the molecular weight difference index is small and the molecular weight distribution is narrow, all of which can yield high-quality target products.

[0047] Batch stability test: Example 15 was repeated using the same preparation method and reaction apparatus as Example 1. The resulting products were denoted as 15-1, 15-2, 15-3, and 15-4. The performance parameters are shown in Table 5. According to the data in the table, the batch stability coefficient Q of Example 15 was calculated to be 0.18. This means that when synthesizing the same product in different batches, the product obtained by the apparatus and process of this invention has small batch differences, good stability, high conversion rate, and narrow molecular weight distribution, which reduces the quality instability and application difficulty caused by batch differences in downstream applications.

[0048] The formula for calculating the batch stability coefficient Q is: Q=E H Where E is the volatility coefficient, which is calculated as follows: E=(g 最大 -g 最小 ) / g 理论中值 Where g 理论中值 This refers to the theoretical value (g) across all batches tested. 理论1、 g 理论2 ...g 理论n The median of the difference, H, is the average difference, which is calculated as follows: H = √(1 / n(g1-g))理论1 ) 2 +(g2-g 理论2 ) 2 +(g3-g 理论3 ) 2 +...(g) n -g 理论n ) 2 g 最大 Maximum molecular weight among all batches, g 最小 The minimum molecular weight for all batches, g1, g2, g3...g n The values ​​represent the molecular weight for each batch.

[0049] Q calculation examples (using Examples 1 and 15 as examples): Q = (2068 - 2033) / 2032 √1 / 5 ((2016-2033)) 2 +(2035+2056) 2 + (2032-2061) 2 + (2032-2053) 2 + (2042-2068) 2 =0.399 This demonstrates that the device and process of this application produce products with small batch-to-batch variations, good stability, high conversion rate, and narrow molecular weight distribution, thereby reducing quality instability and application difficulties caused by batch-to-batch differences in downstream applications.

[0050] Table 5. Batch stability test performance parameters of succinic acid type polycarbonate polyether polyol in Example 15 Comparative Example 1 Compared with the apparatus 1 of Example 1, Comparative Example 1 uses a circular hole dispersion sheet with a hole diameter of 3 mm and a hole center-to-center distance of 6 mm. The rest are prepared and tested according to the method of Example 1. The three batches of products obtained are denoted as CK1-1, CK1-2 and CK1-3, and the performance parameters are shown in Table 6.

[0051] Comparative Example 2 Compared with the apparatus 1 of Example 1, Comparative Example 2 does not have a circulating pump and a gas-liquid mixing heat conduction zone. Instead, multiple tubular reactors are connected in series, with materials and CO2 entering from one end and products exiting from the other end. The rest are prepared and tested according to the methods of Example 1. The three batches of products obtained are denoted as CK2-1, CK2-2, and CK2-3, and their performance parameters are shown in Table 6.

[0052] Comparative Example 3 Compared with the apparatus 2 of Example 2, Comparative Example 3 does not have an inlet for replenishing carbon dioxide from the bottom, that is, it only replenishes the pressure to the reaction pressure from the top. All other aspects refer to the preparation method and detection method of Example 2. The three batches of products obtained are denoted as CK3-1, CK3-2 and CK3-3, and the performance parameters are shown in Table 6.

[0053] Comparative Example 4 Compared with apparatus 2 in Example 2, Comparative Example 4 has a reaction pipe length-to-diameter ratio of 50:1. The rest are prepared and tested according to the methods of Example 2. The three products obtained are denoted as CK4-1, CK4-2, and CK4-3, and their performance parameters are shown in Table 6.

[0054] Comparative Example 5 Compared with device 1 in Example 1, the triangular holes in the dispersion sheet are arranged irregularly and are not arranged in a centrally symmetrical or axially symmetrical manner. The rest are prepared and tested according to the method of Example 1. The product obtained is denoted as CK5, and the performance parameters are shown in Table 6.

[0055] Comparative Example 6 Compared with device 1 in Example 1, the porosity of the dispersion sheet used is 30%, and the rest are prepared and tested according to the methods in Example 1. The resulting product is denoted as CK6, and the performance parameters are shown in Table 6.

[0056] Comparative Example 7 Compared with Example 1, the premixing unit uses a conventional stirring paddle instead of the continuous carbon dioxide bubbling method of the present invention for premixing. All other aspects refer to the preparation and testing methods of Example 1. The resulting product is denoted as CK7, and the performance parameters are shown in Table 6.

[0057] Table 6. Parameters of the succinic acid type polycarbonate polyether polyol products of Comparative Examples 1-7 In Comparative Example 1, due to the precipitation of succinic acid, the actual molecular weight of the synthesized product deviated significantly from the theoretical molecular weight, and this deviation was uncontrollable. The batch stability index was also too high, making this type unsuitable for the synthesis of succinic acid-based polycarbonate polyether polyols. In Comparative Example 2, although no succinic acid precipitated, propylene oxide vaporized and escaped from the reaction pipe due to the outlet at the other end, resulting in a reduction in propylene oxide. This led to lower ester content, a wider molecular weight distribution, and uncontrollable batch stability. In Comparative Examples 3 and 4, although the batch stability was less than 10, the ester content was low, and the molecular weight distribution was too wide. This was because insufficient CO2 content during the reaction process made explosive polymerization more likely. In Comparative Example 5, due to the irregular distribution of pores in the dispersion sheet, the falling material is not easily dispersed, resulting in less carbon dioxide absorption in the gas-liquid mixing heat conduction zone, more polyether formation, more heat release, faster reaction rate, and wider molecular weight distribution. In Comparative Example 6, the use of a lower porosity also resulted in insufficient dispersion of the liquid material in the gas-liquid mixing heat conduction zone, leading to less carbon dioxide absorption. Conversely, when the porosity is too high, the spacing between pores is too small, which also results in insufficient dispersion. In Comparative Example 7, the lack of 40°C carbon dioxide bubbling during premixing, relying solely on heat transfer from the reactor wall, reduces the dissolution rate of succinic acid. Furthermore, the uneven distribution of succinic acid in propylene oxide, coupled with the absence of bubbling at the beginning of the reaction, resulted in a low initial carbon dioxide content. All these factors combined led to a faster initial reaction rate, resulting in a higher molecular weight distribution.

[0058] Based on the above embodiments and comparative examples, it can be seen that the tubular reactor of the present invention uniformly mixes the raw materials in one go through the premixing unit. Combined with the tubular reactor structure design and parameter settings of the reaction unit, a one-time feeding production process for succinic acid-type polycarbonate polyether polyol is realized. Through the synergistic effect of process parameters such as the premixing method and corresponding specific tubular reactor features such as the shape of the dispersion sheet structure, pore distribution characteristics, and open porosity, the problems of wide molecular weight distribution, significantly larger molecular weight than the target value, and easy explosive polymerization of succinic acid-type polycarbonate polyether polyol in the prior art are solved. Unexpectedly, the molecular weight distribution of the prepared succinic acid-type polycarbonate polyether polyol is narrow, the difference between the actual product molecular weight and the target theoretical value is small, the molecular weight of the product is stable in different batches, the production process is safe, no explosive polymerization occurs, there is no scale-up effect, and it is suitable for large-scale industrial production.

Claims

1. A tubular reaction apparatus for succinic acid-type polycarbonate polyether polyols, characterized in that, The tubular reaction device includes a premixing unit (001) and a reaction unit (002). The premixing unit is used to fully mix carbon dioxide with epoxy compound, succinic acid and DMC catalyst in a bubbling manner to obtain a premix. The premix is ​​fed into the reaction unit (002) in one go. The reaction unit (002) includes at least one tubular reactor (022). The tubular reactor (022) includes a dispersion plate (222) and a reaction pipe (223). The reaction pipe (223) includes a gas-liquid mixing heat conduction zone (2231) and a solid-liquid mixing zone (2232). The flow direction of the premix is ​​through the gas-liquid mixing heat conduction zone (2231) to the solid-liquid mixing zone (2232), and then back to the gas-liquid mixing heat conduction zone (2231) to complete the cycle. The dispersing plate (222) is used to control the flow rate and direction of materials in the reaction system, disperse and control the materials to be dispersed into liquid droplets in the gas-liquid mixing heat conduction zone (2231) for mass and heat transfer without contacting the pipe wall; the structure of the dispersing plate (222) is a circular porous structure, the holes are equilateral triangular holes, adjacent two triangular holes are centrally symmetrical in the same horizontal direction, and adjacent two triangular holes are axially symmetrical in the same direction perpendicular to the horizontal direction; the porosity of the dispersing plate (222) is 40%-60%; The solid-liquid mixing zone (2232) is used to realize the real-time mixing and polymerization reaction of DMC catalyst and epoxy compound; The tubular reactor (022) is also used to introduce supplemental pressurized carbon dioxide, the direction of which is opposite to the flow direction of the premix, to obtain the succinic acid type polycarbonate polyether polyol through a polymerization reaction. The gas-liquid mixing heat conduction zone (2231) of the reaction pipe (223) is designed to allow the material to reabsorb carbon dioxide and release heat, while preventing excessive atomization of the material that could cause solid evaporation and precipitation on the pipe wall, resulting in material imbalance. It consumes carbon dioxide while replenishing low-temperature carbon dioxide, thus forming a lower temperature zone in this area. The solid-liquid mixing zone (2232) of the reaction pipe (223) is designed to have a gradient increase in reaction temperature along the direction of material flow, with the temperature difference between the material at one end and the material at the other end not exceeding 10°C. The DMC catalyst is a mixed acid-modified zinc-cobalt bimetallic cyanide catalyst, wherein the catalyst contains only zinc and cobalt, excluding impurities. The catalyst is obtained by reacting water-soluble metal salts of zinc and cobalt in a water-soluble solvent, wherein the water-soluble metal salt of cobalt is a cyanide salt of cobalt. The catalyst is synthesized by modification with a mixed acid, which comprises at least one organic acid and at least one water-soluble inorganic acid. The water-soluble inorganic acid is selected from dilute sulfuric acid and dilute hydrochloric acid, and has a pH value between 0 and 5. The organic acid is selected from any one or more of succinic acid, glutaric acid, phthalic acid, iminodiacetic acid, pyromellitic acid, and butanetetracarboxylic acid, and the molar ratio of the water-soluble inorganic acid to the organic acid is 1:10 to 10:

1. The reaction unit (002) of the tubular reactor is composed of one or more tubular reactors (022) connected in parallel, and the liquid circulation path formed between each tubular reactor (022) and the connecting pipe (228) and the circulating pump (021) is the same; the ratio of the diameter of the dispersion plate (222) to the inner diameter of the reaction pipe (223) is 1:1; the volume of the gas-liquid mixing heat conduction zone (2231) occupies 20% ≤ V of each reaction pipe (223). 气液混合热传导区 <100%; the reaction pressure of the reaction unit (002) is 3-4 MPa; the reaction temperature of the solid-liquid mixing zone (2232) is 70-90℃.

2. The tubular reaction apparatus for succinic acid-type polycarbonate polyether polyols according to claim 1, characterized in that, The reaction pipeline (223) is equipped with a temperature sensor inside and a density detector at the outlet. The jacket temperature is adjusted according to the material density and the internal temperature of the reactor to control the reaction rate.

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