| 摘要 |
<p>1435965 Separation of olefin polymers NATIONAL PETRO-CHEMICALS CORP 1 May 1973 [1 May 1972] 20670/73 Heading C3P An olefin is polymerized by producing a slurry of the solid olefin polymer in a liquid diluent within a polymerization zone, passing the product slurry directly to a separation zone, removing from the separation zone an overflow stream concentrated in the liquid diluent and an underflow stream concentrated in the solid polymer, taking off a portion of the underflow stream for recovery of the solid polymer, combining the overflow stream with the residual portion of the underflow stream, and recycling the resulting mixture to the polymerization zone. A pressure gradient may be maintained in the polymerization zone between the region from which the polymer slurry is removed and that to which the recycle mixture is returned, the pressure gradient providing the motive force for the feed to the separation zone and the recycle therefrom. The separation zone suitably comprises a cyclone separator. The product slurry may be produced in a continuous loop reaction zone. The preferred polymerization is that of ethylene in the presence of chromium oxide, organometallic or other catalyst systems.</p> |
