Patent ID: 8344078

Claim:
A method of producing a polyolefin, comprising: providing a feed comprising a diluent and a first monomer to a first polymerization reactor; polymerizing the first monomer in the first polymerization reactor to form a first polyolefin in a first slurry; discharging a transfer slurry comprising the first polyolefin and the diluent continuously from the first polymerization reactor to a second polymerization reactor; polymerizing a second monomer in the second polymerization reactor to form a second polyolefin in a second slurry; discharging the second slurry from the second polymerization reactor; and controlling a pressure in the first polymerization reactor and a pressure in the second polymerization reactor by modulating only continuous take-off of the second slurry from the second polymerization reactor along with the feed into the first polymerization reactor.