Polyether polyol synthesizer
By installing a mixing reactor on the polyether polyol reactor, the Venturi effect makes the starting agent fully contact with the epoxy compound, solving the problems of difficulty in causing reaction and high reaction pressure, and achieving the effect of shortening reaction time and improving production efficiency.
Patent Information
- Application Number
- CN202510141932.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-09
- Publication Date
- 2025-03-28
AI Technical Summary
In the existing polyether polyol synthesis process, it causes difficulty in reaction and high reaction pressure, resulting in low production efficiency and safety hazards.
A mixing reactor is installed on a reactor of polyether polyol, and the starting agent is circulated through the Venturi effect and fully contacted with the epoxy compound in the mixing reactor, shortening the reaction time and reducing the reaction pressure.
It effectively shortens the polymerization reaction time, improves production efficiency, reduces the pressure in the reactor, and improves the safety production coefficient.
Smart Images
Figure CN119701843A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a polyether polyol synthesis device, and in particular to a mixing reactor installed on a polyether polyol production reactor, so that a polyether polyol liquid initiator is fully in contact with propylene oxide, effectively solving the problems of difficult initiation reaction and high reaction pressure, while effectively shortening the polymerization reaction time and improving production efficiency. Background Art
[0002] Polyether polyol is an organic polymer, which is obtained by initiation reaction, addition polymerization reaction and aging reaction of initiator (compound containing active hydrogen group) and ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO) etc. in the presence of catalyst. The largest polyether production is to use glycerol (propylene glycol) as initiator and epoxide (generally P0 and EO are used together). By changing the feeding method of P0 and EO (mixed or separate), the feeding ratio, the feeding order and other conditions, various general polyether polyols are produced. Polyether polyol series products are mainly used for the preparation of rigid polyurethane foam plastics, and are widely used in refrigerators, freezers, refrigerated trucks, insulation boards, pipe insulation and other fields.
[0003] At present, the commonly used catalysts for polyether polyols include potassium hydroxide, bimetallic catalysts, phosphazene catalysts, etc. Among them, bimetallic catalysts and phosphazene catalysts cannot be used in the polymerization reaction of small molecule initiators. Potassium hydroxide can be used as a catalyst for the polymerization reaction of small molecule initiators, but potassium hydroxide needs to be firstly reacted with the small molecule initiator through reduced pressure dehydration to prepare potassium alcoholate, and then the potassium alcoholate is polymerized with the epoxy compound to prepare polyether polyols. However, there are difficulties in initiating the reaction during the reaction of potassium alcoholate with the epoxy compound, which makes the epoxy compound gasified in the reactor, reduces the contact efficiency between the initiator and the epoxy compound, and causes the pressure in the reactor to be too high, which poses a safety hazard. In the face of the above problems, most companies choose to reduce the feeding rate of the epoxy compound and extend the process operation of initiation reaction time for production, but the above process operation has the problems of low efficiency, energy waste, poor economic benefits, etc. Therefore, a new polyether polyol synthesis device is proposed. Summary of the invention
[0004] The object of the present invention is to provide a reaction device for polyether polyols, wherein a mixing reactor is installed on a reactor for producing polyether polyols, wherein a feed port of the mixing reactor is connected to a discharge port of a circulating pump, and a discharge port of the mixing reactor is connected to the reactor. A gas phase port of the mixing reactor is connected to a gas phase pipe of the reactor, and a discharge port of the feed pipe of the mixing reactor is lower than the level of the gas phase port.
[0005] The mixing reactor of the present invention is designed according to the Venturi principle and is a pipeline type mixing reaction device. The initiator is transported into the mixing reactor through a circulation pump and refluxed into the reactor through the outlet of the mixing reactor under its own gravity. During the process of the initiator being transported and flowing out of the mixer, the mixer is in a negative pressure state, and the gas phase epoxy compound is sucked into the mixing reactor from the top of the reactor through a gas phase pipe to complete initiation and polymerization reaction with the initiator. During the aging process, the reactor discharge port, the reactor gas phase pipe and the mixing reactor discharge port valve are in a closed state.
[0006] The working principle of the polyether polyol production unit:
[0007] After the epoxy compound enters the reactor through the feed pipeline, a small part directly initiates the reaction with potassium alcohol, and most of it is vaporized and escapes the initiator solution to the top of the reactor. The initiator is externally circulated through a circulation pump, enters from the feed port at the top of the mixing reactor, and then returns to the reactor from the lower discharge port. During the initiator circulation process, due to the Venturi effect, the unreacted epoxy compound at the top of the reactor is sucked into the mixing reactor through the gas phase pipe, and is mixed and contacted with the circulating initiator again to complete the initiation and polymerization reaction, thereby shortening the reaction time and reducing the pressure of the reactor.
[0008] The beneficial effects of the present invention are as follows: (1) compared with a conventional reactor, a reactor equipped with a mixing reactor does not need to reduce the feeding rate of the epoxy compound during the initiation process, thereby shortening the initiation reaction time and improving production efficiency; (2) after the mixing reactor is installed, the interior of the reactor always maintains a slightly negative pressure state during the initiator circulation process, which is beneficial to the absorption of the epoxy compound and increases the contact effect between the initiator and the epoxy compound, thereby facilitating the reactor to maintain a relatively low pressure during the initiation and polymerization process, reducing the risk of overpressure during the synthesis process, and improving the safety factor of production. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 This is a schematic diagram of the structure of a polyether polyol production device.
[0011] In the figure: 1. Motor; 2. Feed pipeline; 3. Stirring shaft; 4. Reactor; 5. Paddle; 6. Reactor discharge port; 7. Mixing reactor feed port; 8. Mixing reactor; 9. Mixing reactor feed pipe; 10. Mixing reactor discharge port; 11. Mixing reactor gas phase port; 12 Reactor gas phase pipe; 13. Circulation pump. DETAILED DESCRIPTION
[0013] Example 1
[0014] Feeding: Add 460g sorbitol, 160g glycerol and 9g potassium hydroxide into the reactor, and perform nitrogen leak test and replacement on the reactor.
[0015] Preparation of potassium alcoholate: After nitrogen replacement, the temperature was raised to 105°C and dehydrated at -0.095 MPa for 2 hours to prepare potassium alcoholate.
[0016] Initiate reaction: cool to 85°C and start feeding propylene oxide. Maintain reactor pressure at 0.25 MPa during feeding. Feeding time is 1 hour. During the initiation of reaction, keep reactor outlet valve, mixing reactor outlet valve, reactor gas phase pipe valve in open state and circulation pump in on state.
[0017] Polymerization reaction: After the initiation reaction is completed, the material temperature is raised to 110°C and propylene oxide is started to be fed. The reactor pressure is maintained at 0.25Mpa. The feeding time is 6 hours. The reactor outlet valve, the mixing reactor outlet valve, and the reactor gas phase pipe valve are kept open throughout the process, and the circulation pump is turned on.
[0018] Ripening reaction: After the polymerization reaction is completed, the material is heated to 120°C and matured for 2 hours. The discharge valve of the reactor, the discharge valve of the mixing reactor, the gas phase pipe valve of the reactor are closed, and the circulation pump is shut down.
[0019] Post-treatment: adding phosphoric acid to neutralize the matured material, adding an adsorbent to adsorb potassium dihydrogen phosphate, filtering, and drying to obtain polyether polyol.
[0020] Comparative Example 1
[0021] Feeding: Add 460g sorbitol, 160g glycerol and 9g potassium hydroxide into the reactor, and perform nitrogen leak test and replacement on the reactor.
[0022] Preparation of potassium alcoholate: After nitrogen replacement, the temperature was raised to 105°C and dehydrated at -0.095 MPa for 2 hours to prepare potassium alcoholate.
[0023] Initiate the reaction: cool to 85°C and start feeding propylene oxide. During the feeding process, maintain the reactor pressure at 0.25 MPa. The feeding time is 1.5 hours.
[0024] Polymerization reaction: After the initiation reaction was completed, the material temperature was raised to 110°C and propylene oxide was started to be fed. The pressure of the reactor was maintained at 0.25 MPa and the feeding time was 7.5 hours.
[0025] Ripening reaction: After the polymerization reaction is completed, the material is heated to 120°C and ripened for 2 hours.
[0026] Post-treatment: adding phosphoric acid to neutralize the matured material, adding an adsorbent to adsorb potassium dihydrogen phosphate, filtering, and drying to obtain polyether polyol.
[0027] It can be seen from the comparative examples and the embodiments that the time required for synthesizing polyether polyols by using the equipment of the present invention is shortened from 9 hours in the traditional synthesis reactor to 7 hours, and the synthesis efficiency is increased by 22%.
Claims
1. A polyether polyol production device, comprising a kettle body (4), a motor (1) installed above the kettle body, and a stirring shaft (3) connected to the motor, the stirring shaft extending into the interior of the kettle body, a stirring paddle (5) installed at the bottom of the stirring shaft, a liquid raw material feed pipeline (2) at the top of one side of the kettle body, a discharge port (6) at the bottom of the reactor, the discharge port is connected to the feed port of a circulation pump (13), the discharge port of the circulation pump is connected to the feed port (7) at the top of a mixing reactor (8), the discharge port (10) at the bottom of the mixing reactor is connected to the reactor body, the reactor is provided with a gas phase pipe (12) connected to the gas phase air inlet (11) of the mixing reactor, and the height of the discharge port (9) of the feed pipe of the mixing reactor is lower than the horizontal height of the air inlet (11).
2. The production device of polyether polyol according to claim 1, characterized in that: The liquid feed pipeline (2) is mainly used for feeding liquid raw materials such as sorbitol, glycerol, propylene glycol, diethylene glycol, ethylene oxide, and propylene oxide.
3. The production device of polyether polyol according to claim 1, characterized in that: The discharge port (6) at the bottom of the reactor, the discharge port (9) at the bottom of the mixing reactor and the gas phase pipe (12) are provided with valves respectively. The valves are in an open state during the initiation of the reaction and the synthesis process, and are in a closed state during the later maturation process.
4. The production device of polyether polyol according to claim 1, characterized in that: The discharge port (6) at the bottom of the reactor is connected to the feed port (7) at the top of the mixing reactor via a circulation pump (13).
5. The production device of polyether polyol according to claim 1, characterized in that: The mixing reactor (8) is designed according to the Venturi principle and is a tubular reactor. The mixing reactor (8) is provided with a feed port (7) at the top, a discharge port (10) at the bottom, an air inlet pipe (11) at the side, and a feed pipe (9) inserted into the mixing reactor. The discharge port of the feed pipe (9) is lower than the level of the air inlet (11).
6. The production device of polyether polyol according to claim 1, characterized in that: The gas phase pipe (12) is connected to the gas inlet pipe (11) of the mixing reactor (8).