Polypropylene production process and production device

Abstract

The invention relates to a polypropylene production process and a polypropylene production device. The production process comprises the following steps: polymerizing liquid-phase propylene in a liquid-phase reaction system under the action of a catalyst; introducing a solid-liquid mixture generated by the polymerization reaction into a pressure separation system for solid-liquid separation under the condition of not carrying out other solid-liquid separation; feeding filtrate obtained by solid-liquid separation into a liquid-phase reaction system to be used as a propylene raw material; feedinga solid separated material obtained by the solid-liquid separation into a steaming system and a drying system for steaming liquid removal and drying to form homo-polypropylene powder. The productiondevice comprises the corresponding liquid phase reaction system, the pressure separation system, a propylene feeding system, the steaming system, the drying system and the like. The process and the production device have the advantages of being small in equipment number, short in flow and high in process operability, one-time investment of project construction is reduced, and meanwhile the problemof huge energy consumption caused by liquid phase reactor discharging gasification, flash evaporation, propylene recompression and condensation liquefaction in a traditional process is solved.

Description

technical field [0001] The invention provides a polypropylene production process based on liquid-phase bulk reaction and a corresponding production device, belonging to the technical field of olefin polymerization. Background technique [0002] Polypropylene is a thermoplastic synthetic resin with excellent performance, which has been widely used in various industrial and civilian plastic products such as injection molding, film blowing, coating, spinning, and modified engineering plastics. At present, the production process of polypropylene can be divided into solution method, slurry method, bulk method, gas phase method and bulk-gas phase combined process according to the polymerization type. Among them, the solution method and the slurry method have long process flow and high operating and investment costs. Since the 1980s, the new and rebuilt large-scale polypropylene plants basically no longer use this process. [0003] The bulk method (bulk-gas phase method) has a var...

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Problems solved by technology

[0009] 1) Unreacted liquid-phase propylene requires a large amount of steam tracing and cooling water to condense and liquefy in the above-mentioned cycle of gasification, flash evaporation, compression, and condensation, resulting in a large amount of public works consumption;

[0010] 2) The separation of propylene powder and gasified propylene gas requires multiple filters and separators, which not only results in high equipment investment costs, but also has a long process flow, which increases the unreliability of device operation;

[0011] 3) The compression of a large amount of circulating propylene gas requires a large compressor capacity and a high cost of equipment investment; at the same time, the compression of a large amount of propylene gas consumes a large amount of electric energy

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