US Patent 12129365 Methods for operating polyethylene reactor systems

A method of operating a polyethylene reactor system includes feeding ethylene, an optional first comonomer, a diluent, and a chromium-based catalyst to a first polymerization reactor. The method further includes contacting ethylene and the comonomer with the catalyst in the first polymerization reactor to form a first product including a first polyethylene. The method further includes feeding the first product from the first polymerization reactor to a second polymerization reactor. The method further includes contacting ethylene and a second optional comonomer with catalyst from the first reactor in the second polymerization reactor to form a second product including the first polyethylene and a second polyethylene. The method further includes controlling one or both of a molecular weight or a breadth of molecular weight distribution of the second product by adjusting a rate of hydrogen fed to one or both of the first polymerization reactor or the second polymerization reactor.