Process for the oligomerization of olefins employing a cleaning device

Patent metadata

Field	Value
Publication number	US-2018179122-A1
Application number	US-201715850641-A
Country	US
Kind code	A1
Filing date	Dec 21, 2017
Priority date	Dec 22, 2016
Publication date	Jun 28, 2018
Grant date	—

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

1 . A process for the oligomerization of ethylene into alpha-olefins, comprising:
a step for oligomerization of the ethylene in a reaction section ( 1 ) comprising a reactor ( 10 ), in the presence of a catalyst, and optionally a diluent, a step for deactivation of the catalyst contained in the reaction effluent, a step for evaporation of the products contained in the reaction effluent in order to separate them from the deactivated catalyst, carried out in an evaporation section ( 2 ), a step for separation of the products contained in the reaction effluent 103 in a separation section ( 3 ),
said reactor being provided with at least one cooling loop ( 100 a/b , 101 a/b , 102 a/b ), by means of which the reaction medium is caused to move through at least two switchable heat exchangers which are capable of being connected to at least one cooling loop in a manner such that when at least one heat exchanger is operatively connected to at least one cooling loop, the other disconnected heat exchanger undergoes a step for cleaning by means of a cleaning device in which a solvent which is capable of cleaning said heat exchanger is caused to move in a loop, the cleaning device comprising:
a storage drum ( 40 ) for the cleaning solvent,
a heat exchanger ( 43 ) for 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;
a recirculation pump ( 42 ) for moving the cleaning solvent in a loop in the cleaning device between the cleaning solvent storage drum ( 40 ), the heat exchanger ( 43 ) for the cleaning solvent and the disconnected heat exchanger which is to be cleaned.

2 . The process as claimed in claim 1 , in which at least a portion of the cleaning solvent obtained from the solvent loop of the cleaning device ( 406 ) is sent to the product evaporation step in the evaporation section ( 2 ).

3 . The process as claimed in claim 1 , in which the reaction medium ( 103 ) is moved in a heat exchanger ( 20 ) in which it is vaporized in the evaporation section ( 2 ).

4 . The process as claimed in claim 1 , in which the unreacted ethylene separated in the separation step in the separation section ( 3 ) is recycled to the reactor (stream 306 ).

5 . 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 the polymer deposited in the disconnected heat exchanger.

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

7 . The process as claimed in claim 1 , in which the cleaning solvent is selected from saturated hydrocarbons; unsaturated hydrocarbons; aromatic hydrocarbons; a gasoline, diesel or kerosene cut; and isoparaffins; used alone or as a mixture.

8 . The process as claimed in claim 1 , in which at least a portion of the cleaning solvent comes from the step for separation in the separation section ( 3 ) (stream 305 ).

9 . 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 step.

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

11 . The process as claimed in claim 1 , in which, once the polymer has been dissolved in the cleaning solvent, at least a portion of the 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 vapour phase 409 and at least one liquid phase 410 .

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

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

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

15 . A facility comprising:
a reaction section ( 1 ) comprising a reactor ( 10 ), a section ( 2 ) for evaporation of the reaction effluent, a separation section ( 3 ),
said reactor being provided with at least one cooling loop ( 100 a/b , 101 a/b , 102 a/b ) by means of which at least one reaction medium is caused to move through at least two switchable heat exchangers which are capable of being connected to at least one cooling loop in a manner such that when at least one heat exchanger is operatively connected to at least one cooling loop, the other disconnected heat exchanger undergoes a step for cleaning by means of a cleaning device in which a solvent which is capable of cleaning said heat exchanger is caused to move in a loop, the cleaning device comprising:
a storage drum ( 40 ) for the cleaning solvent,
a heat exchanger ( 43 ) for 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;
a recirculation pump ( 42 ) for moving the cleaning solvent in a loop in the cleaning device between the cleaning solvent storage drum ( 40 ), the heat exchanger ( 43 ) for the cleaning solvent and the disconnected heat exchanger which is to be cleaned.

16 . A facility as claimed in claim 15 , in which the cleaning device is connected to the evaporation section ( 2 ) via at least one conduit which may be used to send at least a portion of the cleaning solvent to said section ( 2 ) for evaporation of the reaction effluent.

Assignees

• Axens
• Ifp Energies Now

Inventors

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

Classifications

• C07C2/30

  containing metal-to-carbon bond; Metal hydrides · CPC title

• B01J2231/20

  Olefin oligomerisation or telomerisation · CPC title

• B01J2219/00103

  in a heat exchanger separate from the reactor · CPC title

• F28D2021/0022

  for chemical reactors · CPC title

• C07C2/08 Primary

  Catalytic processes · CPC title