Process for the preparation of ethylene homopolymers or copolymers
AssigneeBasell Polyolefine GmbH
InventorsChristoph Wolf, Dieter Littmann, Michael Deuerling, Andre-Armand Finette, Danir Khayrullin, Juergen Mohrbutter
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Abstract
A process for the preparation of ethylene homopolymers or copolymers in a facility having a high-pressure tubular reactor and a preheater, wherein a reaction fluid introduced into the reactor at a reactor inlet is heated in the preheater and the average velocity of the reaction fluid in the preheater is lower than the average velocity of the reaction fluid in the tubular reactor and the ratio of the average velocity in the tubular reactor to the average velocity of the reaction fluid in the preheater is in the range from 1.5 to 5.
Claims20
A process for the preparation of ethylene homopolymers or copolymers in a facility
- having i) a high-pressure tubular reactor used in a continuous flow mode with a reaction fluid comprising ethylene being introduced into the reactor at a reactor inlet and polymer leaving the reactor at a reactor outlet and ii) a preheater having an inlet and an outlet, comprising the steps of:
- a) compressing the reaction fluid to an elevated pressure;
- b) heating at least a portion of the reaction fluid in the preheater;
- c) introducing the reaction fluid heated in step b) into the reactor at the reactor inlet;
- and
- d) polymerizing the reaction fluid at the elevated pressure in the presence of free-radical polymerization initiators in the reactor, thereby yielding a polymer selected from the group consisting of ethylene homopolymers and ethylene copolymers,
- wherein the average velocity of the reaction fluid at the outlet of the preheater is lower than the average velocity of the reaction fluid in the tubular reactor at the reactor inlet and the ratio of the average velocity of the reaction fluid in the tubular reactor at the reactor inlet to the average velocity of the reaction fluid in the preheater at the outlet of the preheater is in the range from 1.5 to 5.
A process for the preparation of ethylene homopolymers or copolymers in a facility having i) a high-pressure tubular reactor used in a continuous flow mode with a reaction fluid comprising ethylene being introduced into the reactor at a reactor inlet and polymer leaving the reactor at a reactor outlet and ii) a preheater having an inlet, an outlet, a first preheater unit is arranged on a first branch line, and a second preheater unit is arranged on a second branch line, comprising the steps of:
- a′) providing a first flow of compressed reaction fluid comprising a first portion of the reaction fluid and providing a second flow of compressed reaction fluid comprising a second portion of the reaction fluid by, in any order, compressing the reaction fluid to an elevated pressure and splitting at least a portion of a single flow of the reaction fluid into the first flow and the second flow of compressed reaction fluid;
- b′) conducting the first flow of the first portion of the reaction fluid through the first preheater unit and heating the first portion of the reaction fluid in the first preheater unit, and conducting the second flow of the second portion of the reaction fluid through the second preheater unit and heating the second portion of the reaction fluid in the second preheater unit;
- c′) combining the first and second portion of the reaction fluid by recombining the first flow and the second flow of the reaction fluid and introducing the recombined flow of the reaction fluid heated in step b′) into the reactor at the reactor inlet;
- and
- d′) polymerizing the reaction fluid at the elevated pressure in the presence of free-radical polymerization initiators in the reactor, thereby yielding a polymer selected from the group consisting of ethylene homopolymers and ethylene copolymers, wherein the average velocity of the reaction fluid at the outlet of the preheater is lower than the average velocity of the reaction fluid in the tubular reactor at the reactor inlet and the ratio of the average velocity of the reaction fluid in the tubular reactor at the reactor inlet to the average velocity of the reaction fluid in the preheater at the outlet of the preheater is in the range from 1.5 to 5.
Dependencies are inferred from the claim text.