Olefin polymerization apparatus and process for its production
By employing a gas-liquid distributor and a fast-switching valve design in the olefin polymerization reactor, molecular-level mixing is achieved, solving the problem of poor mixing effect in multiple reactors in the prior art, and improving polymer performance and production efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- WANHUA CHEM GRP CO LTD
- Filing Date
- 2024-01-15
- Publication Date
- 2026-07-10
AI Technical Summary
Existing olefin polymerization processes cannot achieve molecular-level mixing of different phases, resulting in limited mechanical and optical properties of the polymers, and require multiple reactors to produce impact-resistant products.
By employing a specially structured gas-liquid distributor and a fast-switching valve design, molecular-level mixing of olefins is achieved within the reactor. The "U"-shaped structure and guide vane design of the gas-liquid distributor ensure uniform mixing of raw materials, and the fast-switching valve enables rapid replacement of different raw materials. A vertical stirred bed reactor with jacketed cooling is used, combined with online chromatographic detection and hydrogen regulation to optimize reaction conditions.
Achieving molecular-level mixing of multiple polymers within a single reactor enhances the mechanical and optical properties of the product, simplifies the production process, and improves production efficiency.
Smart Images
Figure CN117899789B_ABST
Abstract
Claims
1. An olefin polymerization reaction apparatus, characterized in that, It includes a reactor, in which a stirrer is provided. A polymerization monomer feed inlet is provided on the side wall of the reactor, and a discharge outlet for polymerized powder is provided at the bottom of the reactor. A gas-liquid distributor is provided inside the reactor. The gas-liquid distributor has a "return" - shaped structure. After the raw materials at the reactor feed inlet enter, they pass through the gas-liquid distributor and enter the interior of the reactor for reaction. The gas-liquid distributor includes an L-shaped feed channel, a gas-liquid distribution chamber, and a discharge channel. A guiding vane is provided at the end of the discharge channel. The angle between the guiding vane and the vertical direction is less than the angle of repose of the powder, so that the powder cannot pass through the gas-liquid distributor reversely.
2. The reaction apparatus according to claim 1, characterized in that, The angle between the guiding vane and the vertical direction is 15 - 25°.
3. The reaction apparatus according to claim 2, characterized in that, The angle between the guiding vane and the vertical direction is 15 - 20°.
4. The reaction apparatus according to claim 1, characterized in that, The reaction raw materials enter the reactor from the polymerization monomer feed inlet and then enter the gas-liquid reactor along the feed channel of the gas-liquid distributor. They are mixed in the gas-liquid distribution chamber and discharged from the gas-liquid distributor through the discharge channel and the guiding vane. The gas and liquid are discharged along the guiding vane. The angle between the guiding vane and the tangent direction of the reactor cross-section is 15 - 65°. Among them, the angle between the discharge direction of the gas-liquid distributor and the tangent direction of the stirring direction is less than 90°.
5. The reaction apparatus according to claim 4, characterized in that, The inclined angle between the guiding vane and the tangent direction of the reactor cross-section is 25 - 45°.
6. The reaction apparatus according to claim 1, characterized in that, The spacing L0 between the guiding vanes of the "return" - shaped gas-liquid distributor is 1.5 - 3.0 cm.
7. The reaction apparatus according to claim 6, characterized in that, The spacing L0 between the guiding vanes of the "return" - shaped gas-liquid distributor is 2.0 - 2.5 cm.
8. The reaction apparatus according to claim 1, characterized in that, The spacing L1 between the feed channels of the "return" - shaped gas-liquid distributor is 1.5 - 4.0 cm.
9. The reaction apparatus according to claim 8, characterized in that, The spacing L1 between the feed channels of the "return" - shaped gas-liquid distributor is 2.0 - 3.0 cm.
10. The reaction apparatus according to claim 1, characterized in that, The width spacing L3 of the gas-liquid distributor is 2.0 - 6.0 cm.
11. The reaction apparatus according to claim 10, characterized in that, The width spacing L3 of the gas-liquid distributor is 3.0 - 5.0 cm.
12. The reaction apparatus according to claim 1, characterized in that, The gas-liquid distributors are combined together through grid plates.
13. The reaction apparatus according to claim 1, characterized in that, A plurality of the gas-liquid distributors are provided and distributed inside the reactor, being concentric circles with the reactor.
14. The reaction apparatus according to claim 1, characterized in that, A gas-liquid distributor is also provided at the bottom of the reactor, which is in a conical distribution. The included angle between it and the gas-liquid distributor distributed on the reactor cylinder is 125 - 165°.
15. The reaction apparatus according to claim 14, characterized in that, A gas-liquid distributor is also provided at the bottom of the reactor, which is in a conical distribution. The included angle between it and the gas-liquid distributor distributed on the reactor cylinder is 135 - 155°.
16. The reaction apparatus according to claim 1, characterized in that, The reactor feed inlet is connected to the raw material tank through a feed pipe and a quick-switching valve.
17. The reaction apparatus according to claim 1, characterized in that, The reactor is a vertical stirred-bed reactor with jacket cooling water, and the length-diameter ratio is controlled at 8:1 - 14:
1.
18. The reaction apparatus according to claim 17, characterized in that, The reactor is a vertical stirred-bed reactor with jacket cooling water, and the length-diameter ratio is 10:1 - 12:
1.
19. The reaction apparatus according to claim 1, characterized in that, The bulk density of the powder in the reactor during fluidization is 320 - 400 kg / m³.
20. The reaction apparatus according to claim 19, characterized in that, The rotational speed of the stirrer is controlled at 15 - 20 rpm.
21. The reaction apparatus according to claim 1, characterized in that, The olefin polymerization reaction equipment further includes a cyclone separator, a stripping tower, an olefin separator, and a raw material tank. A gas phase outlet is provided at the top of the reactor. The gas phase outlet is connected to the cyclone separator. The bottom of the cyclone separator is connected to the reactor to discharge the unreacted gas phase polymerization monomer. The fine powder entrained in the gas falls back to the reactor through the bottom of the cyclone separator. The gas discharged from the cyclone separator enters the stripping tower after heat exchange through a heat exchanger.
22. An olefin polymerization process using the reaction equipment described in any one of claims 1-21, wherein a catalyst, a co-catalyst, a solvent, and an optional external electron donor are added to the reactor, and then hydrogen is introduced to add the raw material olefin into the reactor from the monomer feed port of the reactor. The olefin is fully mixed by a gas-liquid distributor before entering the reactor for reaction. When the reaction is completed and the raw material needs to be switched, different raw material gases are quickly switched by a fast switching valve.