Integrated processes for producing bis(fluorosulfonyl) imide
A process for producing bis(fluorosulfonyl) imide includes providing a solution comprising fluorosulfonic acid and urea, the solution maintained at a solution temperature from about 0° C. to about 70° C.; reacting the solution in the presence of a reaction medium at a reaction temperature from 80° C. to about 170° C. to produce a product stream including bis(fluorosulfonyl) imide, ammonium fluorosulfate and the reaction medium; separating the ammonium fluorosulfate from the product stream to produce an intermediate product stream; and separating the intermediate product stream into a concentrated product stream and a first recycle stream, the concentrated product stream including a higher concentration of bis(fluorosulfonyl) imide than the first recycle stream.
1 . A process for producing bis(fluorosulfonyl) imide, the process comprising:
providing a solution comprising fluorosulfonic acid and urea, the solution maintained at a solution temperature from about 20° C. to about 50° C. and at a mole ratio of fluorosulfonic acid to urea of at least 2.5;
reacting the solution in the presence of a reaction medium at a reaction temperature from about 100° C. to about 150° C. to produce a product stream including bis(fluorosulfonyl) imide, ammonium fluorosulfate and the reaction medium;
separating the ammonium fluorosulfate from the product stream to produce an intermediate product stream; and
separating the intermediate product stream into a concentrated product stream comprising bis(fluorosulfonyl) imide and a first recycle stream, the concentrated product stream including a higher concentration of bis(fluorosulfonyl) imide than the first recycle stream.
2 . The process of claim 1 , further comprising recycling the first recycle stream back to the reacting step.
3 . The process of claim 2 , wherein the process is a continuous process.
4 . The process of claim 1 , further comprising recycling the first recycle stream to a storage tank.
5 . The process of claim 4 , wherein the process is a semi-batch process.
6 . The process of claim 1 , wherein the reaction medium includes fluorosulfonic acid.
7 . The process of claim 1 , wherein a concentration of bis(fluorosulfonyl) imide in the first recycle stream is less than 50 wt. % of the first recycle stream.
8 . The process of claim 1 , wherein in the providing step, the solution comprising fluorosulfonic acid and urea is formed by mixing the urea and the fluorosulfonic acid together at the solution temperature.
9 . The process of claim 8 , wherein in the providing step, the solution comprising fluorosulfonic acid and urea is formed by mixing the fluorosulfonic acid and the urea together at a mole ratio of from about 2.5:1 to about 3.0:1.
10 . The process of claim 1 , wherein separating the intermediate product stream into the concentrated product stream and the first recycle stream includes distilling the product stream.
11 . The process of claim 1 , wherein separating the ammonium fluorosulfate from the product stream includes evaporating the product stream to form the intermediate product stream.
12 . The process of claim 1 , further comprising:
separating the concentrated product stream comprising bis(fluorosulfonyl) imide into a further concentrated product stream comprising bis(fluorosulfonyl) imide and a second recycle stream, the further concentrated product stream including a higher concentration of bis(fluorosulfonyl) imide than the second recycle stream.
13 . The process of claim 1 , wherein in the providing step, the solution is maintained at a solution temperature from about 30° C. to about 50° C.
14 . The process of claim 1 , wherein in the providing step, the mole ratio of fluorosulfonic acid to urea is at least 2.7.
15 . The process of claim 1 , wherein in the providing step, the mole ratio of fluorosulfonic acid to urea is at least 2.8.
16 . The process of claim 1 , wherein the reacting step is conducted at a reaction temperature from about 110° C. to about 140° C.
17 . The process of claim 1 , wherein the reacting step is conducted at a reaction temperature from about 120° C. to about 130° C.
18 . The process of claim 7 , wherein a concentration of bis(fluorosulfonyl) imide in the first recycle stream is less than 30 wt. % of the first recycle stream.
19 . The process of claim 7 , wherein a concentration of bis(fluorosulfonyl) imide in the first recycle stream is less than 10 wt. % of the first recycle stream.
20 . The process of claim 7 , wherein a concentration of bis(fluorosulfonyl) imide in the first recycle stream is less than 5 wt. % of the first recycle stream.