Patent ID: 8450435
Filing Date: 2013-05-28
Classification: C08F

Abstract:
1. A method to reduce the rate of fouling of the heat exchangers in a gas phase reactor system at a temperature from 75° C. to 110° C. and a pressure less than 500 psi (3,447 kPa) in the presence of a gaseous feed consisting of a monomer feed consisting of from 80 to 100 weight % of ethylene and from 0 to 20 weight % of a C 4-6 alpha olefin; nitrogen; and hydrogen so that the reactor system does not need to be brought down for cleaning more frequently than 24 months consisting of: i) continuously operating the reactor in condensed mode at condensable alkane levels not less than 13 weight % based on the weight of the recycle stream; ii) using a Zielgler Natta catalyst having a productivity of greater than 1,500 grams of polymer per gram of catalyst (g/g) under standard commercial plant operations to produce an ethylene hexene copolymer having an MI of 1 and a density of 0.918 said catalyst prepared by contacting at a temperature from 0° C. to 100° C. a silica support having a particle size from 10 to 150 microns and a surface area greater than 250 m iii) controlling the feed of a co-catalyst of the formula the formula R