Both a system and method for cleaning a low pressure separation vessel of a high pressure polyethylene polymerization plant are provided. The system includes a polytetrafluoroethylene lining that covers the interior surfaces of the vessel, and a cover mounting assembly including an annular clamp for detachably mounting a cover over the vessel. The mounting assembly includes a clamp actuator for quickly securing and releasing the cover with respect to a top rim of the vessel. The vessel is drained of liquid polyethylene and allowed to cool to ambient temperature, thus creating a frozen skin of polyethylene around the interior surfaces of the vessel. The clamp actuator releases the cover. The polyethylene skin is peeled off the interior sides the vessel and gathered up at the top to form a neck, thus peeling the polyethylene skin away from the polytetrafluoroethylene lining along with any degraded polymers or other impurities that have accumulated on the interior surfaces of the vessel.

The present disclosure relates to a continuous process for the preparation of ethylene homopolymers or ethylene copolymers comprising polymerizing ethylene or copolymerizing ethylene and one or more other olefins in the presence of a chromium catalyst in a gas-phase polymerization reactor which is equipped with a cycle gas line for withdrawing reactor gas from the reactor, leading the reactor gas through a heat-exchanger for cooling and feeding the reactor gas back to the reactor, wherein the polymerization is carried out at a temperature from 30? C. to 130? C. and a pressure of from 0.1 to 10 MPa and an aliphatic carboxylic acid ester having from 8 to 24 carbon atoms is added.

The present disclosure relates to a continuous process for the preparation of ethylene homopolymers or ethylene copolymers comprising polymerizing ethylene or copolymerizing ethylene and one or more other olefins in the presence of a chromium catalyst in a gas-phase polymerization reactor which is equipped with a cycle gas line for withdrawing reactor gas from the reactor, leading the reactor gas through a heat-exchanger for cooling and feeding the reactor gas back to the reactor, wherein the polymerization is carried out at a temperature from 30? C. to 130? C. and a pressure of from 0.1 to 10 MPa and an aliphatic carboxylic acid ester having from 8 to 24 carbon atoms is added.

The present technology relates to a method of introducing a supported antistatic compound that does not comprise a transition-metal-based catalyst component for use in an olefin polymerization reactor. In some embodiments, the methods disclosed herein avoid the formation of polymer agglomerates in the reactor and minimize potentially negative effects on catalyst yield.

The present technology relates to a method of introducing a supported antistatic compound that does not comprise a transition-metal-based catalyst component for use in an olefin polymerization reactor. In some embodiments, the methods disclosed herein avoid the formation of polymer agglomerates in the reactor and minimize potentially negative effects on catalyst yield.

The present disclosure relates to a continuous process for the preparation of ethylene homopolymers or ethylene copolymers comprising polymerizing ethylene or copolymerizing ethylene and one or more other olefins in the presence of a chromium catalyst in a gas-phase polymerization reactor which is equipped with a cycle gas line for withdrawing reactor gas from the reactor, leading the reactor gas through a heat-exchanger for cooling and feeding the reactor gas back to the reactor, wherein the polymerization is carried out at a temperature from 30 C. to 130 C. and a pressure of from 0.1 to 10 MPa and an aliphatic carboxylic acid ester having from 8 to 24 carbon atoms is added.

The present disclosure relates to a continuous process for the preparation of ethylene homopolymers or ethylene copolymers comprising polymerizing ethylene or copolymerizing ethylene and one or more other olefins in the presence of a chromium catalyst in a gas-phase polymerization reactor which is equipped with a cycle gas line for withdrawing reactor gas from the reactor, leading the reactor gas through a heat-exchanger for cooling and feeding the reactor gas back to the reactor, wherein the polymerization is carried out at a temperature from 30 C. to 130 C. and a pressure of from 0.1 to 10 MPa and an aliphatic carboxylic acid ester having from 8 to 24 carbon atoms is added.

In the high pressure polymerization of ethylene homopolymers or copolymers, conditions in the high pressure recycle system may lead to the build-up of low molecular weight oligomers and waxes. Sequentially draining knock-out pots, located downstream of a high pressure separator, at regular intervals can reduce the build-up of low molecular weight oligomers and waxes during the high pressure polymerization of alpha olefins.

In the high pressure polymerization of ethylene homopolymers or copolymers, conditions in the high pressure recycle system may lead to the build-up of low molecular weight oligomers and waxes. Sequentially draining knock-out pots, located downstream of a high pressure separator, at regular intervals can reduce the build-up of low molecular weight oligomers and waxes during the high pressure polymerization of alpha olefins.

Polymerization process for the polymerization of monomer in a polymerization system having at least one component attached thereto which component is flushed with a flush medium which enters the polymerization system. Initially, the component is flushed with a first flush medium, and subsequently the component is flushed with a second flush medium.