Process for preparing low malodor dimethyl sulfoxide

1 . A process for removing dimethyl sulfide from liquid dimethyl sulfoxide comprising:

(a) providing liquid dimethyl sulfoxide comprising dimethyl sulfide; and

(b) treating the liquid dimethyl sulfoxide with a flow of one or more gases so as to reduce the concentration of dimethyl sulfide originally present in the liquid dimethyl sulfoxide before treatment.

2 . The process according to claim 1 , wherein the gas is chosen from nitrogen, helium, argon, carbon dioxide, air, a C 1 -C 5 alkane, and mixtures thereof.

3 . The process according to claim 1 , wherein the gas is introduced into the liquid dimethyl sulfoxide at a temperature of from about 18.6° C. to about 100° C.

4 . The process according to claim 1 , wherein the concentration of dimethyl sulfide is reduced by at least about 50% of the original concentration present in the dimethyl sulfoxide.

5 . The process according to claim 1 , wherein the concentration of dimethyl sulfide is reduced by at least about 99% of the original concentration present in the dimethyl sulfoxide.

6 . The process according to claim 1 , wherein the concentration of dimethyl sulfide present after treatment is an amount less than or equal to about 20 ppm.

7 . The process according to claim 1 , wherein the concentration of dimethyl sulfide present after treatment is an amount less than or equal to about 1 ppm.

8 . The process according to claim 1 , wherein the concentration of dimethyl sulfide present after treatment is an amount less than or equal to about 0.1 ppm.

9 . The process according to claim 1 , wherein after treatment the dimethyl sulfide is at a level that is undetectable.

10 . The process according to claim 1 , wherein the gas is introduced with a sparger.

11 . The process according to claim 1 , wherein the dimethyl sulfide is removed in a continuous process.

12 . The process according to claim 1 , wherein the dimethyl sulfide is removed in a batch process.

13 . The process according to claim 1 , wherein the liquid dimethyl sulfoxide has an initial purity of greater than or equal to about 96%.

14 . A process for removing dimethyl sulfide from dimethyl sulfoxide, comprising the following steps, conducted in any order or simultaneously:

a) contacting liquid dimethyl sulfoxide comprising dimethyl sulfide with stream of a gas; and

b) heating the liquid dimethyl sulfoxide to a temperature of from about 30° C. to about 50° C.;

for a time sufficient to produce treated dimethyl sulfoxide having a concentration of dimethyl sulfide of less than about or equal to about 2 ppm.

15 . A process for deodorizing dimethyl sulfoxide comprising:

(a) providing liquid dimethyl sulfoxide comprising one or more volatile organic compounds; and

(b) introducing into the liquid dimethyl sulfoxide a flow of one or more gases so as to reduce the concentration of one or more volatile organic compounds in the dimethyl sulfoxide by at least about 50% as compared to the concentration of the one or more volatile organic compounds originally present in the liquid dimethyl sulfoxide before treatment.

16 . The process according to claim 15 , wherein the gas is chosen from nitrogen, helium, argon, carbon dioxide, air, a C 1 -C 5 alkane, and mixtures thereof.

17 . The process according to claim 15 , wherein the gas is nitrogen.

18 . The process according to claim 15 , wherein the gas is introduced into the liquid dimethyl sulfoxide at a temperature of from about 18.6° C. to about 100° C.

19 . The process according to claim 15 , wherein the concentration of the volatile organic compounds is reduced by at least about 99% of the original concentration present in the dimethyl sulfoxide.

20 . The process according to claim 15 , wherein the concentration of volatile organic compounds present after treatment is an amount less than or equal to about 2 ppm.

21 . The process according to claim 15 , wherein the liquid dimethyl sulfoxide has an initial purity of greater than or equal to about 96%.

22 . The process according to claim 15 , wherein the volatile organic compounds are chosen from hydrogen sulfide, dimethyl sulfide, crotyl mercaptan, ethyl mercaptan, ethyl methyl sulfide, dimethyl disulfide, or bis(methylthio)methane.

23 . The process according to claim 15 , wherein one of the malodorous compounds is methyl mercaptan.

24 . A process for deodorizing dimethyl sulfoxide comprising (a) initially providing liquid dimethyl sulfoxide comprising one or more malodorous compounds for treatment, and (b) introducing into the liquid dimethyl sulfoxide a flow of one or more gases non-reactive with the dimethyl sulfoxide, so as to reduce the concentration of one or more of the malodorous compounds in the dimethyl sulfoxide by at least about 50% as compared to the concentration of the one or more malodorous compounds originally present in the liquid dimethyl sulfoxide before treatment.

25 . A process for removing dimethyl sulfide from dimethyl sulfoxide, comprising the following steps, conducted in any order or simultaneously:

a) contacting liquid dimethyl sulfoxide comprising dimethyl sulfide with a stream of a non-reactive gas; and

b) heating the liquid dimethyl sulfoxide to a temperature of from about 30° C. to about 50° C.;

for a time sufficient to produce treated dimethyl sulfoxide having a concentration of dimethyl sulfide of less than about or equal to about 2 ppm.