Process for the oligomerization of olefins employing a cleaning device

Patent metadata

Field	Value
Publication number	US-10370307-B2
Application number	US-201715850641-A
Country	US
Kind code	B2
Filing date	Dec 21, 2017
Priority date	Dec 22, 2016
Publication date	Aug 6, 2019
Grant date	Aug 6, 2019

Abstract

The invention concerns a process for the oligomerization of ethylene into alpha-olefins, comprising a step for the oligomerization of ethylene, a step for deactivation of the catalyst, a and step for separation of the products, the reactor being provided with a cooling loop (100, 101, 102) by means of which at least a portion of the reaction effluent is moved through at least two switchable heat exchangers, said heat exchangers being cleaned alternately by means of an integrated cleaning device.

First claim

The invention claimed is:

1. A process for oligomerization of ethylene into alpha-olefins, comprising:
oligomerizing the ethylene in a reaction section ( 1 ) comprising a reactor ( 10 ), in the presence of a catalyst, and optionally a diluent, to produce a reaction effluent,
deactivating the catalyst contained in the reaction effluent,
evaporating in an evaporation section ( 2 ) the reaction effluent in order to separate a portion of the reactant effluent from the deactivated catalyst, and
separating in a separation section ( 3 ) products contained in the reaction effluent,
said reactor being provided with at least one cooling loop ( 100 a/b , 101 a/b , 102 a/b ), by which reaction medium is caused to move through at least two switchable heat exchangers which are capable of being connected to the at least one cooling loop in a manner such that when at least one heat exchanger is operatively connected to the at least one cooling loop, the other heat exchanger is disconnected and undergoes cleaning by a cleaning device in which a cleaning solvent which is capable of cleaning said heat exchanger is caused to move in a loop of solvent of the cleaning device, the cleaning device comprising:
a cleaning solvent storage drum ( 40 );
a heat exchanger ( 43 ) heating the cleaning solvent to a temperature above 130° C. in a manner such as to allow the polymer deposited in the disconnected heat exchanger to be dissolved thereby producing a charged solvent; and
a recirculation pump ( 42 ) moving the cleaning solvent in the loop of solvent of the cleaning device through the cleaning solvent storage drum ( 40 ), the heat exchanger ( 43 ) and the disconnected heat exchanger which is to be cleaned,

wherein the process further comprises sending at least a portion of cleaning solvent obtained from the loop of solvent of the cleaning device to the evaporation section ( 2 ).

2. The process as claimed in claim 1 , in which the reaction effluent is moved in a heat exchanger ( 20 ) in which the reaction effluent is vaporized in the evaporation section ( 2 ).

3. The process as claimed in claim 1 , in which the unreacted ethylene separated in the separation section ( 3 ) is recycled to the reactor.

4. The process as claimed in claim 1 , in which the heat exchanger ( 43 ) heats the cleaning solvent to a temperature of more than 150° C. in a manner such as to dissolve polymer deposited in the disconnected heat exchanger.

5. The process as claimed in claim 1 , in which the charged solvent has a concentration of polymers and heavy oligomers less than 5% by weight with respect to the cleaning solvent.

6. The process as claimed in claim 1 , in which the cleaning solvent is a saturated hydrocarbon; unsaturated hydrocarbon; aromatic hydrocarbon; a gasoline, diesel or kerosene cut; or an isoparaffin; used alone or as a mixture.

7. The process as claimed in claim 1 , in which at least a portion of the cleaning solvent comes from the separation in the separation section ( 3 ).

8. The process as claimed in claim 1 , in which at least a portion of the cleaning solvent originates from heavier compound fractions and/or from an optional diluent separated from the separation section ( 3 ).

9. The process as claimed in claim 1 , in which a filter ( 39 ) is employed on the loop of solvent of the cleaning device for moving cleaning solvent ( 402 , 403 , 404 , 405 ).

10. The process as claimed in claim 1 in which, once the polymer has been dissolved in the cleaning solvent, at least a portion of charged cleaning solvent is depressurized and directed towards a partial vaporization step by means of a flash drum 46 , in order to produce at least one vapor phase 409 and at least one liquid phase 410 .

11. The process as claimed in claim 1 , in which the ethylene oligomerization process is a process for dimerization of ethylene to 1-butene.

12. The process as claimed in claim 1 , in which the ethylene oligomerization process is a process for the trimerization of ethylene to 1-hexene.

13. The process as claimed in claim 1 , in which the ethylene oligomerization process is a process for tetramerization of ethylene to 1-octene.

Assignees

• Axens
• Ifp Energies Now

Inventors

• Boutrot Catherine
• Janot Nicolas
• Liege Xavier
• Niderkorn Etienne
• Pigourier Jerome
• Vinel Daniel Jean
• Favre Frederic
• Magna Lionel

Classifications

• B01J2219/00252

  Formation of deposits other than coke · CPC title

• F28G9/00

  Cleaning by flushing or washing, e.g. with chemical solvents (appliances using jets of fluid for removing debris F28G1/16, F28G3/16) · CPC title

• C07C2531/38

  of titanium, zirconium or hafnium · CPC title

• B01J2219/00247

  Fouling of the reactor or the process equipment · CPC title

• C07C7/00

  Purification; Separation; Use of additives (working-up undefined gaseous mixtures obtained by cracking hydrocarbon oils C10G70/00) · CPC title