Patent ID: 8058368
Filing Date: 2011-11-15
Classification: B01J,C08F

Abstract:
1. A method for gas-phase polymerization of alpha-olefin comprising the steps of: supplying circulation gas including one or more alpha-olefins and inert gas into a polymerization reactor; polymerizing the alpha-olefin to polyolefin in two separated polymerization areas in the polymerization reactor; and discharging produced polyolefin from the polymerization reactor, wherein, in the polymerization reactor, a fluidized bed where the alpha-olefin is polymerized is divided into the two polymerization areas by a draft tube, and an inside of the draft tube forms a riser where growing polyolefin polymers move up in fast fluidization, and an outside of the draft tube forms an annulus where the polyolefin polymers passing the riser move down by gravity, and the riser and the annulus are connected by a penetration hole formed in the lower part of the draft tube, and the polyolefin polymers passing the annulus are introduced to a lower part of the riser again through the penetration hole, so that the polyolefin polymers are polymerized during circulating between the riser and the annulus.