Process for improving the polymerization of ethylene and one or more optional comonomer(s) in a polymerization loop reactor

摘要

The present invention relates to a process for improving the polymerization of ethylene and one or more optional co-monomer(s) in a polymerization loop reactor characterized in that said process comprises the step of controlling the hydrogen/monomer ratio along the path of the reactor by multiple, spatially separated, feeding of hydrogen along the path of the loop reactor. In particular, the invention provides a process for controlling, and preferably narrowing, the molecular weight distribution of the produced polymer particles. In another aspect, the invention relates to a polymerization loop reactor suitable for the polymerization process of ethylene and an optional olefin co-monomer, wherein the molecular weight distribution of the produced ethylene polymer can be controlled.

主权项

1. A double loop reactor system comprising:
a first loop reactor and a second loop reactor in series having a flow path for a polymer slurry, wherein the polymer slurry comprises monomer, one or more optional co-monomers, a polymerization catalyst, liquid diluent and solid ethylene polymer particles; multiple feedings for feeding hydrogen into the double loop reactor, which are positioned spatially separated along a path of the double loop reactor, wherein the location of the multiple feedings for feeding hydrogen are chosen by a function of hydrogen/monomer ratio; a pump suitable for maintaining the polymer slurry in circulation in said reactor; one or more controllers adapted to control a hydrogen:monomer along the flow path by feeding hydrogen into the multiple feedings for feed hydrogen and reducing the variation in the hydrogen:monomer ratio between the ratio at the double loop reactor inlet and at the double loop reactor outlet to a variation that is lower than 40%; one or more settling legs connected to the pipes of the double loop reactor for settling of polymer slurry; and one or more lines for discharging settled polymer slurry out of the double loop reactor.