Polypropylene Process by Mitsui Chemicals, Inc.

To produce polypropylene (PP) including homopolymer, random copolymer and impact copolymer.

Polypropylene Process by Mitsui Chemicals, Inc.

The process, with a combination of the most advanced high-yield and high-stereospecificity catalyst, is a nonsolvent, nondeashing process. It eliminates atactic polymers and catalyst residue removal. The process can produce various grades of PP with outstanding product quality. Polymer yields of 20,000 kg/kg to 100,000 kg/kg of supported catalyst are obtained, and the total isotactic index of polymer can reach 98% to 99%.

With new catalysts based on di-ether technology (fifth-generation catalyst, RK-Catalyst and RH-Catalyst), the process can produce wider melt index ranged polymers due to the high hydrogen response of RK/RH-Catalyst.

The reactor polymer has narrow and controlled particle size distribution that stabilizes plant operation and also permits easy shipment as powder. Due to the proprietary design of gas-phase reactor, no fouling is observed during the operation, and, consequently, reactor cleaning after producing impact copolymer is not required. In addition, the combination of the flexibility of the gas-phase reactor and high-performance catalysts allow processing impact copolymer with high ethylene content.

In the process, homopolymer and random copolymer polymerization occurs in the loop-type reactor (1). For impact copolymer production, copolymerization is performed in a gas-phase reactor (2) after homopolymerization. The polymer is discharged from a gas-phase reactor and transferred to the separator (3). Unreacted gas accompanying the polymer is removed by the separator and recycled to the reactor system. The polymer powder is then transferred to the dryer system (4) where remaining propylene is removed and recovered. The dry powder is pelletized by the pelletizing system (5) along with required stabilizers.

Products: The process can produce a broad range of polypropylene polymers, including homopolymer, random copolymer and impact copolymer, which become high-quality grades that can cover various applications.

Licensor: Mitsui Chemicals, Inc.

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