Process for the production of hydrogen peroxide

1. Process for the production of hydrogen peroxide comprising a liquid-liquid extraction step, said extraction step comprising contacting an organic feed solution containing hydrogen peroxide with an extraction solvent comprising less than about 30 wt % of water to achieve extraction of hydrogen peroxide to said extraction solvent and obtaining an extract containing hydrogen peroxide.

2. Process as claimed in claim 1 , wherein the density of the extraction solvent is from about 950 to about 1800 kg/m 3 .

3. Process as claimed in claim 1 , wherein log K ow at 25° C. and atmospheric pressure for the non-aqueous part of the extraction solvent is below 0.

4. Process as claimed in claim 1 , wherein the vapour pressure of non-aqueous part of the extraction solvent at 50° C. is below about 10 kPa.

5. Process as claimed in claim 1 , wherein the extraction solvent comprises an at least partially organic salt comprising at least one kind of organic cation and/or organic anion.

6. Process as claimed in claim 5 , wherein the content of at least partially organic salt in the extraction solvent is from about 50 wt % to 100 wt %.

7. Process as claimed in claim 5 , wherein the at least partially organic salt comprises a cation selected from the group consisting of 1-alkyl-3-methyl imidiazolium, 1,2,3-trimethyl imidazolium, 1-methyl imidazolium, N-alkylpyridinium, N-butyl pyridinum, pyrrolidinium, guanidinium, alkyl guanidinium, isouronium, tetramethyl isothiouronium, PR 4 + , SR 3 + , NR 4 + , and mixtures thereof, R being, independently of each other, optionally substituted alkyl, alkenyl or aryl, or hydrogen.

8. Process as claimed in claim 5 , wherein the at least partially organic salt comprises an anion selected from the group consisting of hexafluorophosphate, tetrafluoroborate, fluorosulphonate, hexafluoroantimonate hexafluoroarsenate, chloroaluminate, bromoaluminate, bis(trifluoromethylsulphonyl)imide, tris(trifluoromethylsulphonyl)methide, tricyanomethide, dicyanamide, nonafluorobutanesulphonate, trifluoromethane sulphonate, 2,2,2-trifluororethanesulphonate, nitrate, sulphate, hydrogen sulphate, phosphate, RPO 4 2− , R 2 PO 4− , R 2 PO 2 − , perchlorate, actetate, alkylsulphonate, bis(2-ethylhexyl)sodium sulphosuccinate, diethyleneglycolmonomethylethersulphate, alkyloligoethersultfate, pivalate, tetraalkylborate, propionate, succinate, saccharinate, glycolate, stearate, lactate, malate, tartrate, citrate, ascorbate, glutamate, benzoate, salicylate, methanesulphonate, toluenesulphonate, and mixtures thereof, R being, independently of each other, optionally substituted alkyl, alkenyl or aryl, or hydrogen.

9. Process as claimed in claim 7 , wherein the at least partially organic salt is selected from the group consisting of 1-methylimidazolium hydrogen sulphate, 1-ethyl-3-methylimidazolium trifluoromethane sulphonate, tetramethyl isothiouronium trifluoro methane sulphonate, choline saccharinate, and mixtures thereof.

10. Process as claimed in claim 1 , wherein the extraction solvent comprises a dendrimeric structure.

11. Process as claimed in claim 1 , wherein the process further comprises a step of recovery of hydrogen peroxide from the extract.

12. Process as claimed in claim 11 , wherein hydrogen peroxide is recovered from the extract by evaporation.

13. Process for the production of hydrogen peroxide comprising the steps of hydrogenating quinones in a working solution, oxidising hydrogenated quinones in said working solution to obtain hydrogen peroxide, and extracting hydrogen peroxide from said working solution, said extraction being a liquid-liquid extraction step and step comprising contacting the working solution containing hydrogen peroxide with an extraction solvent comprising less than about 30 wt % of water to achieve extraction of hydrogen peroxide to said extraction solvent and obtaining an extract containing hydrogen peroxide.

14. Process as claimed in claim 13 , wherein the density of the extraction solvent is from about 950 to about 1800 kg/m 3 .

15. Process as claimed in claim 13 , wherein log K ow at 25° C. and atmospheric pressure for the non-aqueous part of the extraction solvent is below 0.

16. Process as claimed in claim 13 , wherein the vapour pressure of non-aqueous part of the extraction solvent at 50° C. is below about 10 kPa.

17. Process as claimed in claim 13 , wherein the extraction solvent comprises an at least partially organic salt comprising at least one kind of organic cation and/or organic anion.

18. Process as claimed in claim 17 , wherein the content of at least partially organic salt in the extraction solvent is from about 50 wt % to 100 wt %.

19. Process as claimed in claim 17 , wherein the at least partially organic salt comprises a cation selected from the group consisting of 1-alkyl-3-methyl imidiazolium, 1,2,3-trimethyl imidazolium, 1-methyl imidazolium, N-alkylpyridinium, N-butyl pyridinium, pyrrolidinium, guanidinium, alkyl guanidinium, isouronium, tetramethyl isothiouronium, PR 4 + , SR 3 + , NR 4 + , and mixtures thereof, R being, independently of each other, optionally substituted alkyl, alkenyl or aryl, or hydrogen.

20. Process as claimed in claim 17 , wherein the at least partially organic salt comprises an anion selected from the group consisting of hexafluorophosphate, tetrafluoroborate, fluorosulphonate, hexafluoroantimonate hexafluoroarsenate, chloroaluminate, bromoaluminate, bis(trifluoromethylsulphonyl)imide, tris(trifluoromethylsulphonyl)methide, tricyanomethide, dicyanamide, nonafluorobutanesulphonate, trifluoromethane sulphonate, 2,2,2-trifluororethanesulphonate, nitrate, sulphate, hydrogen sulphate, phosphate, RPO 4 2− , R2PO 4 − , R 2 PO 2 − , perchlorate, actetate, alkylsulphonate, bis(2-ethylhexyl)sodium sulphosuccinate, diethyleneglycolmonomethylethersulphate, alkyloligoethersultfate, pivalate, tetraalkylborate, propionate, succinate, saccharinate, glycolate, stearate, lactate, malate, tartrate, citrate, ascorbate, glutamate, benzoate, salicylate, methanesulphonate, toluenesulphonate, and mixtures thereof, R being, independently of each other, optionally substituted alkyl, alkenyl or aryl, or hydrogen.

21. Process as claimed in claim 19 , wherein the at least partially organic salt is selected from the group consisting of 1-methylimidazolium hydrogen sulphate, 1-ethyl-3-methylimidazolium trifluoromethane sulphonate, tetramethyl isothiouronium trifluoro methane sulphonate, choline saccharinate, and mixtures thereof.

22. Process as claimed in claim 20 , wherein the at least partially organic salt is selected from the group consisting of 1-methylimidazolium hydrogen sulphate, 1-ethyl-3-methylimidazolium trifluoromethane sulphonate, tetramethyl isothiouronium trifluoro methane sulphonate, choline saccharinate, and mixtures thereof.

23. Process as claimed in claim 13 , wherein the extraction solvent comprises a dendrimeric structure.

24. Process as claimed in claim 13 , wherein the process further comprises a step of recovery of hydrogen peroxide from the extract.

25. Process as claimed in claim 13 , wherein hydrogen peroxide is recovered from the extract by evaporation.