A high-efficiency PPC synthesis device
By designing the first and second polymerization kettles in the PPC synthesis unit, and utilizing the atomized mixing of homogeneous catalyst and propylene oxide and the further reaction of heterogeneous catalyst, the problems of catalyst adhesion and multi-stage reaction towers were solved, and efficient synthesis of PPC was achieved.
Patent Information
- Application Number
- CN202211661854.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-12-23
- Publication Date
- 2025-09-12
- Estimated Expiration
- 2042-12-23
AI Technical Summary
In existing PPC synthesis technology, the adhesion of reactants on the catalyst surface leads to reduced catalytic efficiency, and the solution polymerization reaction requires multi-stage reaction towers, which has cumbersome steps and low polymerization efficiency, making it difficult to achieve efficient production.
An apparatus design including a first polymerization kettle, a second polymerization kettle, a sprayer, a mixing pump, a coaxial valve, and a three-way valve is adopted. Homogeneous catalyst A is mixed with propylene oxide, atomized, and reacts with carbon dioxide. Then, the mixture further reacts under the action of heterogeneous catalyst B. The reaction conditions are optimized by controlling the airflow and pressure.
The synthesis rate of PPC is accelerated, the synthesis rate of PPC is increased, the reaction steps are simplified, and the production efficiency is improved.
Smart Images
Figure CN116272691B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of PPC synthesis, in particular to a high-efficiency PPC synthesis device. Background Art
[0002] Carbon dioxide is one of the main gases that cause the greenhouse effect. The emission of large amounts of carbon dioxide has a great harm to the ecological environment. However, it is also a cheap and non-toxic chemical industrial raw material. It can be copolymerized with propylene oxide to form polypropylene carbonate (PPC). PPC is a biodegradable and environmentally friendly plastic. PPC has good ductility, elongation at break, and resistance to corrosion.
[0003] It is heat-resistant and impact-resistant, and has excellent biodegradability. It is one of the current low-carbon, environmentally friendly, biodegradable plastics. It is one of the few degradable plastics that can be stretched into films and is a high-performance degradable plastic. Under appropriate conditions, it can be buried underground and degraded by microorganisms. It is widely used in packaging films, foams, cable wrapping, etc.
[0004] The polymerization reaction of PPC includes bulk polymerization and solution polymerization. Bulk polymerization causes propylene oxide and carbon dioxide to spontaneously polymerize only under the action of a catalyst. The catalyst is generally a heterogeneous catalyst and is generally carried out in a reactor. Solution polymerization uses a solvent to dissolve the monomer and catalyst. The catalyst is generally a homogeneous catalyst and is generally carried out in a reaction tower. During bulk polymerization, as the reaction proceeds, the reactants on the catalyst surface will quickly generate PPC, which adheres to the catalyst surface, resulting in isolation between the catalyst and the reactants, reducing the catalytic efficiency, and thus making it difficult to produce PPC efficiently. Solution polymerization is to dissolve the catalyst in a solution. The reaction has two aspects: one is that the carbon dioxide in the solution reacts with propylene oxide to undergo a polymerization reaction; the other is that the carbon dioxide contacts the surface of the solution to undergo a polymerization reaction. Although this can improve the utilization rate of the catalyst, it requires a multi-stage reaction tower, which is cumbersome, slow in reaction time, and low in polymerization efficiency, making it unfavorable for large-scale production. Summary of the Invention
[0005] In order to solve the above-mentioned problems of slow reaction time and low PPC synthesis rate, the present invention provides a high-efficiency PPC synthesis device. By using the device of the present invention, carbon dioxide and propylene oxide can fully react under the action of a catalyst, thereby accelerating the synthesis rate of PPC and improving the synthesis rate of PPC.
[0006] In order to achieve the above object, the technical solution used in the present invention is:
[0007] A high-efficiency PPC synthesis device comprises a first polymerization kettle (5), a second polymerization kettle (8), a sprayer (1), a mixing pump (2), a PPC kettle liquid collecting tank (11), a coaxial valve (3) and a three-way valve (4); the first polymerization kettle (5) is provided with a first feed port, a first air inlet and a first discharge port, the first feed port is connected outwardly to the coaxial valve (3), the sprayer (1) and the mixing pump (2), the first air inlet is connected outwardly to the three-way valve (4), the first polymerization kettle (5) is provided with a fan blade (7), and the first polymerization kettle stirring rod (6) is connected to the fan blade (7); the second polymerization kettle (8) is provided with a second air inlet, a catalyst feed port, a second feed port and a second discharge port, the second air inlet is connected outwardly to the three-way valve (4), the catalyst feed port is connected outwardly to the coaxial valve (3), the second polymerization kettle (8) is provided with a stirring paddle (10), the second polymerization kettle stirring rod (9) is connected to the fan blade (7), and the catalyst feed port is connected outwardly to the coaxial valve (3). The first polymerization kettle (5) and the second polymerization kettle (8) are connected to the stirring paddle (10), the second discharge port is connected to the PPC kettle liquid collecting tank (11) through the coaxial valve (3), and the first discharge port is connected to the second feed port; a motor is provided above the first polymerization kettle (5) and the second polymerization kettle (8), and the two motors are respectively connected downward to the first polymerization kettle stirring rod (6) and the second polymerization kettle stirring rod (9); the pressure in the second polymerization kettle (8) is set to be greater than the pressure in the first polymerization kettle (5); the mixing pump (2) is used to mix the propylene oxide and the catalyst A respectively input into the mixing pump (2) through the coaxial valve (3), the sprayer (1) is used to atomize the mixed liquid output by the mixing pump (2) and input it into the feed port one, the three-way valve (4) is used to respectively pass carbon dioxide into the air inlet one and the air inlet two, the catalyst feed port is used to input catalyst B, and the PPC kettle liquid collecting tank (11) is used to collect the PPC kettle liquid.
[0008] Preferably, the catalyst A is a homogeneous catalyst and is soluble in propylene oxide, and the catalyst B is a heterogeneous catalyst and is insoluble in propylene oxide.
[0009] Preferably, the motor is arranged to rotate in a direction such that the fan blade (7) generates an upward airflow.
[0010] Preferably, the feed port 1 and the air inlet 1 are located on the upper side of the first polymerization kettle (5), and the discharge port 1 is located on the lower side of the first polymerization kettle (5).
[0011] Preferably, the second air inlet, the catalyst feed port, and the second feed port are all located on the upper side of the second polymerization kettle (8), and the second discharge port is located on the lower side of the second polymerization kettle (8).
[0012] Preferably, a heating device is provided in the first polymerization kettle (5).
[0013] The advantages and beneficial effects of the present invention are:
[0014] In the first polymerization kettle, catalyst A is dissolved in propylene oxide and atomized to be fully mixed and reacted with carbon dioxide in the air, which increases the contact opportunities among carbon dioxide, catalyst and propylene oxide, thereby accelerating the synthesis rate of PPC. Catalyst B is added to the second polymerization kettle to catalyze the unreacted propylene oxide, and the pressure is increased to make it fully react, thereby improving the synthesis rate of PPC. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In order to more clearly describe the embodiments of the present invention, the accompanying drawings required for the embodiments are briefly introduced below.
[0016] Figure 1 Schematic diagram of the structure of a PPC synthesis device according to one embodiment of the present invention;
[0017] Figure numerals: 1, sprayer; 2, mixing pump; 3, coaxial valve; 4, three-way valve; 5, first polymerization kettle; 6, stirring rod of first polymerization kettle; 7, fan blade; 8, second polymerization kettle; 9, stirring rod of second polymerization kettle; 10, stirring paddle; 11, PPC kettle liquid collecting tank. DETAILED DESCRIPTION
[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0019] A high-efficiency PPC synthesis device, the specific structure is as follows:
[0020] like Figure 1 As shown, an embodiment of the present invention provides a high-efficiency PPC synthesis device, comprising a first polymerization kettle (5), a second polymerization kettle (8), a sprayer (1), a mixing pump (2), a PPC kettle liquid collection tank (11), a coaxial valve (3) and a three-way valve (4).
[0021] The first polymerization kettle (5) is provided with a feed port 1, an air inlet 1 and a discharge port 1. The feed port 1 is connected outwardly to a coaxial valve (3), a sprayer (1) and a mixing pump (2) in sequence. The air inlet 1 is connected outwardly to a three-way valve (4). A fan blade (7) is provided in the first polymerization kettle (5), and a stirring rod (6) of the first polymerization kettle is connected to the fan blade (7).
[0022] The second polymerization kettle (8) is provided with an air inlet 2, a catalyst feed port, a feed port 2, and a discharge port 2. The air inlet 2 is externally connected to a three-way valve (4), and the catalyst feed port is externally connected to a coaxial valve (3). A stirring paddle (10) is provided in the second polymerization kettle (8). The stirring rod (9) of the second polymerization kettle is connected to the stirring paddle (10). The discharge port 2 is connected to a PPC kettle liquid collection tank (11) via a coaxial valve (3). The discharge port 1 is connected to the feed port 2.
[0023] Motors are provided above the first polymerization kettle (5) and the second polymerization kettle (8), and the two motors are respectively connected downward to the stirring rod (6) of the first polymerization kettle and the stirring rod (9) of the second polymerization kettle.
[0024] The mixing pump (2) is used to mix the propylene oxide and catalyst A respectively input into the mixing pump (2) through the coaxial valve (3). The sprayer (1) is used to atomize the mixed liquid output from the mixing pump (2) and input it into the feed port 1 (the "atomized liquid" referred to below refers to the liquid input into the feed port 1 here). The three-way valve (4) is used to respectively introduce carbon dioxide into the air inlet 1 and the air inlet 2. The catalyst feed port is used to input catalyst B. The PPC kettle liquid collection tank (11) is used to collect the PPC kettle liquid.
[0025] Preferably, the catalyst A is a homogeneous catalyst, which can be dissolved in propylene oxide, and the catalyst B is a heterogeneous catalyst, which is insoluble in propylene oxide. Homogeneous catalysis is that the catalyst can dissolve with the reactants, and the two are in the same phase, and there is no phase boundary to carry out the reaction. The catalyst that can play a catalytic role is called a homogeneous catalyst. The homogeneous catalyst active center is relatively uniform, highly active, highly selective, with fewer side reactions, and a fast reaction rate. Heterogeneous catalysis is that the catalyst is immiscible with the reactants and there is a phase boundary. This catalyst is called a heterogeneous catalyst. The crystal form and active site distribution of heterogeneous catalysts are difficult to control, and are often accompanied by more polyether by-products and a wider molecular weight distribution, resulting in relatively unstable product quality, but low price, suitable for industrial production.
[0026] Preferably, the direction of rotation of the motor is set so that the fan blades generate an upward airflow to prevent the atomized liquid from falling; preferably, the feed port 1 and the air inlet 1 are located on the upper side of the first polymerization kettle (5), and the discharge port 1 is located on the lower side of the first polymerization kettle (5); preferably, the air inlet 2, the catalyst feed port, and the feed port 2 are all located on the upper side of the second polymerization kettle (8), and the discharge port 2 is located on the lower side of the second polymerization kettle (8).
[0027] Based on the above structure, the process of introducing carbon dioxide is as follows: in the first polymerization kettle (5), the atomized liquid is introduced first, and then the carbon dioxide is introduced; in the second polymerization kettle (8), the reaction liquid and catalyst B in the first reaction kettle (5) are introduced first, and then the carbon dioxide is introduced.
[0028] The boiling point of propylene oxide is 34.23 °C. In the first polymerization kettle (5), atomized liquid and carbon dioxide are mixed and reacted in the air. In order to prevent the atomized liquid from condensing, a heating device is set in the first polymerization kettle (5), and the temperature is controlled in the range of 60 °C~70 °C. The pressure can be set to 0.5 MPa. This mixing increases the contact opportunity between the reactants and the catalyst, which accelerates the reaction rate. The reaction time can be set to 1 h. The second polymerization kettle (8) is under the action of catalyst B to make the unreacted propylene oxide fully react with carbon dioxide. The pressure needs to be increased. The pressure in the second polymerization kettle (8) is set to be greater than the pressure in the first polymerization kettle (5). The pressure can be set to 4 MPa and the reaction time is 4 h.
[0029] The application of the present invention is not limited to this embodiment. As long as ordinary technicians in this field make simple replacements, changes and modifications based on the basic concept of the present invention without creative ideas, they should be considered as within the scope of protection of the present invention.
Claims
1. A high-efficiency PPC synthesis device, characterized by: The invention comprises a first polymerization kettle (5), a second polymerization kettle (8), a sprayer (1), a mixing pump (2), a PPC kettle liquid collecting tank (11), a coaxial valve (3) and a three-way valve (4); the first polymerization kettle (5) is provided with a first feed port, a first air inlet and a first discharge port, the first feed port is connected outwardly to the coaxial valve (3), the sprayer (1) and the mixing pump (2), the first air inlet is connected outwardly to the three-way valve (4), the first polymerization kettle (5) is provided with a fan blade (7), and the first polymerization kettle stirring rod (6) is connected to the fan blade (7); the second polymerization kettle (8) is provided with a second air inlet, a catalyst feed port, a second feed port and a second discharge port, the second air inlet is connected outwardly to the three-way valve (4), the catalyst feed port is connected outwardly to the coaxial valve (3), the second polymerization kettle (8) is provided with a stirring paddle (10), the second polymerization kettle stirring rod (9) is connected to the stirring paddle (10), and the stirring paddle (10) is connected to the stirring paddle (10). ), the discharge port 2 is connected to the PPC kettle liquid collecting tank (11) through the coaxial valve (3), and the discharge port 1 is connected to the feed port 2; a motor is provided above the first polymerization kettle (5) and the second polymerization kettle (8), and the two motors are respectively connected downward to the first polymerization kettle stirring rod (6) and the second polymerization kettle stirring rod (9); the pressure in the second polymerization kettle (8) is set to be greater than the pressure in the first polymerization kettle (5); the mixing pump (2) is used to mix the propylene oxide and the catalyst A respectively input into the mixing pump (2) through the coaxial valve (3), the sprayer (1) is used to atomize the mixed liquid output by the mixing pump (2) and input it into the feed port 1, the three-way valve (4) is used to respectively pass carbon dioxide into the air inlet 1 and the air inlet 2, the catalyst feed port is used to input catalyst B, and the PPC kettle liquid collecting tank (11) is used to collect the PPC kettle liquid.
2. A high-efficiency PPC synthesis device according to claim 1, characterized in that: The catalyst A is a homogeneous catalyst and is soluble in propylene oxide, while the catalyst B is a heterogeneous catalyst and is insoluble in propylene oxide.
3. A high-efficiency PPC synthesis device according to claim 1, characterized in that: The motor is arranged to rotate in a direction such that the fan blades (7) generate an upward airflow.
4. The high-efficiency PPC synthesis device according to claim 1, characterized in that: The feed port 1 and the air inlet 1 are located on the upper side of the first polymerization kettle (5), and the discharge port 1 is located on the lower side of the first polymerization kettle (5).
5. The high-efficiency PPC synthesis device according to claim 1, characterized in that: The second air inlet, the catalyst feed port, and the second feed port are all located on the upper side of the second polymerization kettle (8), and the second discharge port is located on the lower side of the second polymerization kettle (8).
6. A high-efficiency PPC synthesis device according to claim 1, characterized in that: A heating device is provided in the first polymerization kettle (5).
Citation Information
Patent Citations
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