Process for the purification of a mixture comprising N-alkyl-hydroxylammonium salts

Patent metadata

Field	Value
Publication number	US-12398091-B2
Application number	US-202017781405-A
Country	US
Kind code	B2
Filing date	Nov 23, 2020
Priority date	Dec 2, 2019
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

The present invention relates to a process for purification of a mixture comprising water, N-alkyl-hydroxylammonium salts and some byproducts wherein from the mixture water and byproducts are distilled off until the purity of N-alkyl-hydroxylammonium salts in the residue is 95% or higher and additionally keeping the water content during and after the distillation≥40 wt.-% according to the residue.

First claim

The invention claimed is:

1. Process for the purification of a mixture comprising three compounds:
a) water,
b) 1 to 60 wt.-% of N-alkyl hydroxylammonium salt of formula I and

wherein:
R1, R2, R3 each independently are selected from the group of H, methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-butyl and tert-butyl,
X is selected from Cl, SO 4 , PO 4 , CH 3 COO, (COO) 2 ,
n dependent of the valence of X in water is a natural number selected from the group of 1, 2 and 3 and

c) byproducts
wherein the process comprises the following steps:
I) putting the mixture into a purification apparatus,
II) bringing the mixture in contact with steam
III) removing a composition comprising water vapor and the byproducts in c) by distillation until the purity of the compound of formula I in b), in the residue is 95% or greater wherein the amount of water in the residue remains during and after the distillation≥40 wt. %.

2. The process according to claim 1 , wherein the purification apparatus is a packed column as it is used for a continuous reverse flow stripping process.

3. The process according to claim 1 , wherein the purification apparatus is a distillation apparatus.

4. The process according to claim 3 , wherein the purification apparatus is a steam distillation apparatus.

5. The process according to claim 1 , wherein water is added either before step II) and/or during and/or after distillation of step III).

6. The process according to a claim 5 , wherein the water that is added during the distillation of step III) in a steam distillation apparatus or in the packed column as it is used for continuous reverse flow stripping process is added as steam.

7. The process according to claim 5 , wherein the water that is added during the distillation of step III) in a distillation apparatus is added according to the following steps:
i) stopping the distillation,
ii) adding the water in liquid form to the residue and
iii) starting the distillation again.

8. The process according to claim 1 , wherein the distillation temperature during step III) is in the range of 10 to 100° C. and the pressure is in the range of 1 to 1000 mbar.

9. The process according to claim 1 , wherein the composition distilled off in step III) comprises more than 50 wt. % of water.

10. The process according to claim 1 , wherein X is Cl and n is 1.

11. The process according to a claim 1 , wherein R 1 is ≠R 2 and R 3 is H.

12. The process according to claim 1 , wherein R 1 is methyl, R 2 and R 3 are H, X is Cl and n is 1.

13. The process according to claim 1 , wherein none of R 1 , R 2 and R 3 is H.

Assignees

• Basf Se

Inventors

• Mormul Jaroslaw Michael
• Kolassa Dieter
• Riedel Dominic
• Teles Joaquim Henrique
• Altenhoff Ansgar Gereon
• Dehn Richard
• Oechsle Peter

Classifications

• C07C209/84 Primary

  Purification · CPC title

• C07C239/10 Primary

  having nitrogen atoms of hydroxylamino groups further bound to carbon atoms of unsubstituted hydrocarbon radicals or of hydrocarbon radicals substituted by halogen atoms or by nitro or nitroso groups · CPC title