Process for the regeneration of an alkaline solution utilized in a process for the extraction of sulphur-containing compounds comprising a washing step

Patent metadata

Field	Value
Publication number	US-2018320089-A1
Application number	US-201815907927-A
Country	US
Kind code	A1
Filing date	Feb 28, 2018
Priority date	Mar 1, 2017
Publication date	Nov 8, 2018
Grant date	—

Abstract

The present invention relates to the field of the extraction of sulphur-containing compounds such as the mercaptans, COS or H 2 S from a hydrocarbon-containing cut. This selective extraction is carried out by bringing the hydrocarbon-containing cut in liquid phase into contact with an alkaline solution, for example soda. The process according to the invention is an improved process for the regeneration of the alkaline solution, making it possible to reduce the quantity of alkaline solution required in the regeneration section

First claim

1 ) Process for the regeneration of a used alkaline solution utilized in a unit for the extraction of the sulphur-containing compounds from a hydrocarbon-containing cut, comprising the following sequence of steps:
a) Sending the used alkaline solution ( 1 a ) into an oxidation reactor ( 4 ) in which it is brought into contact with an oxidizing agent ( 5 ) and a catalyst ( 3 ), said used alkaline solution being heated beforehand to a temperature comprised between 40° C. and 50° C. b) Sending the effluents ( 7 ) of the oxidation reactor ( 4 ) into a separator ( 8 ) from which a hydrocarbon phase rich in disulphides ( 10 ), and a partially regenerated alkaline solution ( 11 ) are extracted, c) Cooling the partially regenerated alkaline solution ( 11 ) originating from step b) to a temperature less than or equal to 45° C., d) Dividing the partially regenerated alkaline solution ( 15 ) cooled in step c) into two flows:
a flow constituting the excess of recirculated alkaline solution which is sent upstream ( 21 a ), or directly ( 22 a ), into the oxidation reactor ( 4 ), and which constitutes the cooling means used to control the rise in temperature of said reactor, and,
a flow ( 21 b ) or ( 22 b ) which continues the regeneration process,
e) Mixing the flow ( 21 b ) or ( 22 b ), originating from step d) with a hydrocarbon-containing cut without sulphur-containing compounds ( 16 ), f) Sending the mixture originating from step e) into a separator ( 18 ) from which a totally regenerated alkaline solution ( 19 ), and a hydrocarbon-containing cut partially enriched with disulphides ( 6 ) are extracted.

2 ) Process for the regeneration of a used alkaline solution according to claim 1 , in which the excess ( 21 a ) of recirculated alkaline solution is sent to the oxidation reactor ( 4 ), via the circuit upstream of said oxidation reactor ( 4 ), in a mixture with the used alkaline solution ( 1 a ).

3 ) Process for the regeneration of a used alkaline solution according to claim 1 , in which the excess ( 22 a ) of recirculated alkaline solution is sent to the oxidation reactor ( 4 ), directly to one or more points of said oxidation reactor ( 4 ).

4 ) Process for the regeneration of a used alkaline solution according to claim 3 , in which the point or points of introduction of the excess of recirculated alkaline solution into the oxidation reactor ( 4 ) are provided with a diffusion means or a mixing means.

5 ) Process for the regeneration of a used alkaline solution according to claim 3 , in which the point or points of introduction of the excess of recirculated alkaline solution into the oxidation reactor ( 4 ) are positioned so as to allow control of the rise in temperature of the oxidation reactor ( 4 ).

6 ) Process for the regeneration of a used alkaline solution according to claim 1 , in which the catalyst employed in the oxidation reactor ( 4 ) is of cobalt or vanadium phthalocyanines type.

7 ) Process for the regeneration of a used alkaline solution according to claim 1 , in which the catalyst employed in the oxidation reactor ( 4 ) is added to the alkaline solution at the inlet of the oxidation reactor ( 4 ), so as to achieve a concentration of catalyst in the alkaline solution comprised between 10 and 1,000 ppm by weight, preferentially between 10 and 500 ppm by weight.

8 ) Process for the regeneration of a used alkaline solution according to claim 1 , in which the oxidation reactor ( 4 ) is equipped with an additional cooling means ( 23 ).

9 ) Process for the regeneration of a used alkaline solution according to claim 1 , in which the excess of recirculated alkaline solution ( 21 a ) or ( 22 a ) is cooled to a temperature at least 5° C. less than that of the partially regenerated alkaline solution, before being sent to the oxidation reactor ( 4 ).

10 ) Process for the regeneration of a used alkaline solution according to claim 1 , in which the hydrocarbon-containing cut to be desulphurized can range from methane to kerosene.

11 ) Installation for the regeneration of a used alkaline solution utilized in a unit for the extraction of the sulphur-containing compounds from a hydrocarbon-containing cut, according to the invention, comprising at least:
an item of equipment ( 2 ) making it possible to heat the used alkaline solution, before its introduction into the oxidation reactor to a temperature comprised between 40° C. and 50° C., an oxidation reactor ( 4 ), in which the used alkaline solution is brought into contact with an oxidizing agent ( 5 ) and a catalyst ( 3 ), a separator ( 8 ) supplied with the effluent originating from the oxidation reactor ( 4 ), from which a hydrocarbon phase rich in disulphides ( 10 ), and a partially regenerated alkaline solution ( 11 ) are extracted, a cooling means ( 14 ) making it possible to cool the partially regenerated alkaline solution ( 11 ) originating from the separator ( 8 ) to a temperature less than or equal to 45° C., a means making it possible to divide the cooled partially regenerated alkaline solution ( 15 ) into two flows: a first flow constituting the excess of recirculated alkaline solution which is sent upstream ( 21 a ), or directly ( 22 a ), into the oxidation reactor ( 4 ), and, a second flow ( 21 b ) or ( 22 b ) which continues the regeneration process a cooling means constituted by the excess of recirculated alkaline solution which is sent upstream ( 21 a ), or directly ( 22 a ), into the oxidation reactor ( 4 ), a means of mixing the flow ( 21 b ) or ( 22 b ), with a hydrocarbon-containing cut without sulphur-containing compounds ( 16 ), a separator ( 18 ) supplied with the mixture, from which a totally regenerated alkaline solution ( 19 ), and a hydrocarbon-containing cut partially enriched with disulphides ( 6 ) are extracted.

12 ) Installation for the regeneration of used alkaline solution according to claim 11 , in which the oxidation reactor is equipped with an additional cooling means ( 23 ).

13 ) Installation for the regeneration of used alkaline solution according to claim 11 , in which an additional cooling means makes it possible to cool the excess of recirculated alkaline solution ( 21 a ) or ( 22 a ) to a temperature at least 5° C. less than that of the cooled partially regenerated alkaline solution ( 15 ).

Assignees

• Axens

Inventors

• Besnault Jean-Michel
• Ferrero Sebastien
• Do Mai Phuong

Classifications

• C10G53/04

  including at least one extraction step · CPC title

• C10G2300/202

  Heteroatoms content, i.e. S, N, O, P · CPC title

• B01D11/04 Primary

  of solutions which are liquid · CPC title

• B01D11/0492

  Applications, solvents used · CPC title

• C10G53/12

  including at least one alkaline treatment step · CPC title