Nippon Petrochemicals Company, Limited

Yoshihisa Yamaguchi

Kunimichi Kubo

Mamoru Yoshikawa

Motokazu Watanabe

Masatoshi Morikawa

Shinjiro Suga

Masahiro Niwa

Eiko Kobayashi

Yasuhiko Sano

Akira Sano

Makoto Jimbo

Hideto Kitada

Ken-ichi Uenishi

Yuji Sugano

In the polymerization of olefins with a vapor phase fluidized bed reactor, the improvement comprises the steps of feeding seed polymer particles and the reaction is then started after feeding an organoaluminum compound on a prescribed basis, thereby avoiding the formation of sheet-like polymer in the initial period of the reaction and the lowering of the bulk density of the product polymer.

Method of vapor phase polymerization of olefins

In the preparation of polyolefin in a vapor phase polymerization using catalysts comprising a solid catalyst component containing titanium and/or vanadium; and magnesium and an organoaluminum compound, when the reaction is stopped for a certain period of time, the restarting of reaction is possible by feeding in the first place an organoaluminum compound into the reaction system with retaining of polymer particles in the reactor.

Method for operating reactor for polymerizing olefins

In the polymerization of olefins using a catalyst comprising an organoaluminum compound and solid catalyst components containing titanium and/or vanadium; and magnesium in a vapor phase fluidized bed, the formation of sheet-like polymer and other abnormal conditions in the initial stage of the polymerization are avoided by means of previous drying of the reactor by feeding an organoaluminum compound prior to the feeding of seed polymer, the quantity of said organoaluminum compound being calculated by the following equation (I):

Method for drying vapor phase reaction system

A process for producing polyolefin with a vapor-phase fluidized-bed reactor, wherein the reaction is started after filling the reactor with particles which contain moisture and/or molecular oxygen and can form a fluidized bed in order to prevent the formation of molten resin which is liable to occur at the start of the reaction and to attain a smooth operation of the reactor.

Method for producing polyolefin

A process for feeding a powder catalyst with a gas intermittently to a high-pressure fluidized bed reactor for the vapor phase polymerization of olefin, wherein the cross section of a catalyst feed pipe is reduced midway through the pipe to thereby make continual catalyst feeding possible and prevent the formation of a lump polymer.

Process for feeding catalyst to fluidized bed for vapor phase

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Kawasaki, Japan

Yoshihisa Yamaguchi