Method for preparing lithium bis(fluorosulphonyl)imide salt

Patent metadata

Field	Value
Publication number	US-11261087-B2
Application number	US-201917056781-A
Country	US
Kind code	B2
Filing date	May 21, 2019
Priority date	May 23, 2018
Publication date	Mar 1, 2022
Grant date	Mar 1, 2022

Abstract

A method for preparing Cl—SO2NHSO2Cl including a step of chlorinating sulphamic acid with at least one chlorinating agent and at least one sulphur-containing agent, the method resulting in a flow F1, preferably liquid, including Cl—SO2NHSO2Cl and a gas stream F2 including HCl and SO2, the method including a step a) of treating the gas stream F2. Also, a method for preparing LiFSl including the abovementioned method for preparing Cl—SO2NHSO2Cl.

First claim

The invention claimed is:

1. A process for the preparation of Cl—SO 2 NHSO 2 Cl comprising a stage of chlorination of sulfamic acid with at least one chlorinating agent and at least one sulfur-containing agent, said process resulting in a stream F1 comprising Cl—SO 2 NHSO 2 Cl and a gas stream F2 comprising HCl and SO 2 , said process comprising a stage a) of treatment of the gas stream F2.

2. The process as claimed in claim 1 , in which stage a) of treatment of the gas stream F2 comprises a stage of bringing said stream F2 into contact with an alkaline aqueous solution, and/or a stage of bringing said stream F2 into contact with a hydrogen peroxide solution, and/or a stage of separation of HCl and SO 2 contained in said stream F2, and/or a stage of absorption of HCl contained in said gas stream F2 in an aqueous solution, and/or a stage of absorption of SO 2 contained in said gas stream F2 in a concentrated sulfuric acid solution.

3. The process as claimed in claim 1 , in which the gas stream F2 comprises:
more than 20% by weight of HCl, with respect to the total weight of said stream F2; and/or
more than 30% by weight of SO 2 , with respect to the total weight of said stream F2.

4. The process as claimed in claim 1 , in which stage a) of treatment of the gas stream F2 comprises i) bringing the gas stream F2 into contact with an alkaline aqueous solution.

5. The process as claimed in claim 1 , in which stage a) of treatment of the gas stream F2 comprises ii) bringing the gas stream F2 into contact with a hydrogen peroxide solution.

6. The process as claimed in claim 5 , in which stage ii) of bringing the gas stream F2 into contact with a hydrogen peroxide solution makes it possible to form and to recover:
a gas stream G2 comprising water and optionally one or more inert gas(es); and
an acid stream L2 comprising water, HCl and H 2 SO 4 .

7. The process as claimed in claim 6 , comprising an additional stage ii-1) of treatment of the stream L2 which comprises bringing said stream L2 into contact with an alkaline aqueous solution, or an additional stage ii-2) of separation of HCl and of H 2 SO 4 contained in the stream L2 in order to form and to recover a stream F3 comprising HCl and a stream F′3 comprising H 2 SO 4 .

8. The process as claimed in claim 1 , in which stage a) of treatment of the gas stream F2 comprises:
iii) an optional stage of compression of said gas stream F2,
iv) a stage of separation of HCl and SO 2 contained in said gas stream F2 resulting in a stream G4 comprising HCl and in a stream F4 comprising SO 2 , it being possible for said stream F4 to be a liquid or gas stream.

9. The process as claimed in claim 8 , in which stage a) comprises an additional stage v) of treatment of the gas stream G4, and/or an additional stage vi) of treatment of the stream F4.

10. The process as claimed in claim 9 , in which said stage v) comprises:
v-1) an optional stage of purification of said gas stream G4,
v-2) a stage of absorption of the hydrochloric acid contained in said gas stream G4 in an aqueous solution, making it possible to form and to recover an aqueous hydrochloric acid solution L5.

11. The process as claimed in claim 9 , in which:
when the stream F4 is a liquid stream, in particular when stage iv) is a separation by distillation, the treatment stage vi) comprises vi-1) bringing said liquid stream F4 into contact with an alkaline aqueous solution, resulting in a gas stream G6 comprising water and optionally one or more inert gas(es) and in an alkaline stream L6 comprising water, chloride ions and sulfite ions;
when the stream F4 is a gas stream, the treatment stage vi) comprises:
vi-2) bringing said gas stream F4 into contact with an alkaline aqueous solution;
or
vi-3) bringing the gas stream F4 into contact with a hydrogen peroxide solution;
or
vi-4) the oxidation of the gas stream F4 in the presence of oxygen in order to form a stream F5 comprising SO 3 , optionally followed;
by a stage vi-4- a ) of absorption of SO 3 contained in said stream F5 in a concentrated sulfuric acid solution, making it possible to form and to recover a gas stream G9, comprising water and optionally one or more inert gas(es), and an oleum L9;
then optionally a stage vi-4- b ) of dilution of the oleum L9 in water, in order to form an aqueous solution L10.

12. The process as claimed in claim 1 , in which stage a) of treatment of the gas stream F2 comprises:
vii) a stage of absorption of the hydrochloric acid contained in said gas stream F2 in an aqueous solution, making it possible to form and to recover a hydrochloric acid solution L11 and a gas stream G11 comprising SO 2 , water and optionally one or more inert gases;
or
x) a stage of absorption of SO 2 contained in said gas stream F2 in a concentrated sulfuric acid solution, making it possible to form and to recover a gas stream G12 comprising HCl and optionally one or more inert gas(es) and a stream L12 comprising water, H 2 SO 4 and SO 2 .

13. The process as claimed in claim 12 , in stage a) of treatment of the gas stream F2 comprises:
a stage viii), subsequent to stage vii), comprising the purification of the solution L11; and
an optional stage ix) of drying the gas stream G11, for example carried out in the presence of calcium sulfate, sodium sulfate, magnesium sulfate, calcium chloride, calcium carbonate, silica gel or molecular sieve.

14. The process as claimed in claim 12 , in which stream L12 is:
subjected, at least partially, to a heating stage, making it possible to form and to recover a gas stream G13 comprising SO 2 and a stream L13 comprising H 2 SO 4 ;
and/or
subjected, at least partially, to a stage of bringing into contact with a hydrogen peroxide solution.

15. The process as claimed in claim 1 , in which the chlorination stage is carried out:
at a temperature of between 30° C. and 150° C.; and/or
with a reaction time of between 1 hour and 7 days; and/or
at a pressure of between 1 bar abs and 20 bar abs.

16. The process as claimed in claim 1 , in which:
the sulfur-containing agent is chosen from the group consisting of chlorosulfonic acid (ClSO 3 H), sulfuric acid, oleum and their mixtures; and/or
the chlorinating agent is chosen from the group consisting of thionyl chloride (SOCl 2 ), oxalyl chloride (COCl) 2 , phosphorus pentachloride (PCl 5 ), phosphonyl trichloride (PCl 3 ), phosphoryl trichloride (POCl 3 ) and their mixtures.

17. A process for the preparation of the lithium salt of bis(fluorosulfonyl)imide comprising the process for the preparation of Cl—SO 2 —NH—SO 2 —Cl as defined according to claim 1 .

Assignees

• Arkema France

Inventors

• Leduc Philippe
• Deur-Bert Dominique

Classifications

• C01B21/093 Primary

  containing also one or more sulfur atoms · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M10/0568

  characterised by the solutes · CPC title

• B01D2251/502

  Hydrochloric acid · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title