METHOD FOR ACTIVATION OF CHROMIUM CONTAINING CATALYST PRECURSOR FOR POLYMERIZATION AND THE RESULTING POLYMERIZATION CATALYST

• US 20130245209A1
• Filed: 11/29/2011
• Published: 09/19/2013
• Est. Priority Date: 11/30/2010
• Status: Active Application

• Current Assignee: Basell Polyolefine GmbH (Lyondellbasell Industries NV)
• Original Assignee: Basell Polyolefine GmbH (Lyondellbasell Industries NV)
• Inventors: De Lange, Paulus, Hecker, Manfred
• Granted Patent: US 10,253,113 B2
• Time in Patent Office: Days
• US Class Current: 526/106
• CPC Class Codes: B01J 2208/00212 Plates; Jackets; Cylinders
• CPC Class Codes: B01J 23/26 Chromium
• CPC Class Codes: B01J 38/32 Indirectly heating or cooling material within regeneration zone or prior to entry into regeneration zone
• CPC Class Codes: B01J 8/1836 Heating and cooling the reactor B01J8/42 takes precedence
• CPC Class Codes: B01J 8/22 gas being introduced into the liquid
• CPC Class Codes: C08F 10/00 Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
• CPC Class Codes: C08F 4/24 Oxides
• CPC Class Codes: Y02P 20/584 Recycling of catalysts

Abstract

Method for activation of chromium containing catalyst precursor for polymerization and improved polymerization catalyst resulting The instant invention relates to an activation of a polymerization catalyst precursor by heat treatment comprising a support material and a catalyst precursor deposited thereon in a fluidized bed activator and to the use of the activated polymerization catalyst in the manufacture of polyolefins. The Method is performed in a cylindrical activator (1) arranged vertically comprising tubular activator walls, a fluidization gas inlet (2) near the bottom, a fluidization gas outlet (3) near the top and a heat exchange jacket (4) outside the tubular activator walls, wherein the heating jacket covers the complete outer surface of the walls of the activator. The catalyst prepared by that method is improved with respect to its minor content of impurities and causes less interruptions during gas-phase polymerization or slurry polymerization either in stirred vessel or loop.

Claims

1. A method for the preparation of a Cr-containing polymerization catalyst comprising a fluidized-bed method for the activation of the chromium containing catalyst precursor by heat treatment, wherein the heat treatment is performed in an activator in the presence of oxygen at a temperature in the range of from 300 to 1000°

C. over a time period of from 0.5 to 48 h in an activator having an inner activator chamber surrounded by metallic walls, whereby the activator comprises on the outer surface of the walls a heating jacket covering the complete outer surface of the walls.

2. The method of claim 1, wherein the heating jacket is a double heating jacket.

3. The method of claim 1, wherein the supply of the heating medium to the heating jacket is arranged on top of the activator and the outlet of the heating medium is arranged downwards, near the bottom of the activator.

4. The method of claim 1, wherein air is used as an oxygen source to oxidize Cr(III) to Cr(VI).

5. The method of claim 1, wherein the heat treatment is performed in a cylindrical activator (1) arranged vertically comprising an inner activator chamber, tubular activator walls, a fluidization gas inlet (2) near the bottom, a fluidization gas outlet (3) near the top and a heat exchange jacket (4) outside the tubular activator walls covering the complete outer surface of the tubular actortor walls.

6. The method of claim 1 wherein the resulting chromium catalyst does not contain any impurities in the form of Cr₂O₃-particles.

7. The method of claim 6, wherein the catalyst is used in gas-phase polymerization or slurry polymerization in stirred vessel or loop.

8. The method of claim 6, further comprising the step of polymerizing olefins in gas-phase process or in slurry.

9. The method of claim 8, wherein the olefins comprise ethylene or propylene or butene or pentene or hexene including mixtures of these olefins.