Method for purifying borazane

Patent metadata

Field	Value
Publication number	US-10144649-B2
Application number	US-201615759925-A
Country	US
Kind code	B2
Filing date	Sep 16, 2016
Priority date	Sep 18, 2015
Publication date	Dec 4, 2018
Grant date	Dec 4, 2018

Abstract

A method for purifying solid borazane (NH3BH3 (s)) includes a) bringing solid borazane (NH3BH3 (s)) containing impurities into contact with a stream of gaseous ammonia (NH3 (g)) to obtain, by selective liquefaction of the borazane, a liquid phase containing liquefied borazane and ammonia and a solid phase constituted of at least a part of the impurities, b) separating the liquid and solid phases for recovery of the liquid phase, on the one hand, and of the solid phase, on the other hand; c) removing the ammonia from the recovered liquid phase, this removal causing precipitation of the purified borazane (NH3BH3 (s′)); and d) recovering the purified precipitated borazane (NH3BH3 (s′)).

First claim

The invention claimed is:

1. A method for purifying solid borazane (NH 3 BH 3 (s) ) containing impurities, said method comprising:
a) bringing solid borazane (NH 3 BH 3 (s) ) containing impurities into contact with a stream of gaseous ammonia (NH 3 (g) ) to obtain, by selective liquefaction of the borazane, a liquid phase containing liquefied borazane and ammonia and a solid phase constituted of at least a part of said impurities;
b) separating said liquid and solid phases for recovery of said liquid phase, on the one hand, and of said solid phase, on the other hand;
c) removing the ammonia from said recovered liquid phase, the removal causing precipitation of the purified borazane (NH 3 BH 3 (s′) ); and
d) recovering said purified precipitated borazane (NH 3 BH 3 (s′) ).

2. The method as claimed in claim 1 , wherein it is performed at atmospheric pressure and at room temperature.

3. The method as claimed in claim 1 , wherein it is performed continuously.

4. The method as claimed in claim 1 , wherein said solid borazane (NH 3 BH 3 (s) ) is in dispersed form or in undispersed form.

5. The method as claimed in claim 1 , wherein the gaseous ammonia (NH 3 (g) ) is used in a gaseous ammonia/solid borazane mole ratio (R═NH 3 (g) /NH 3 BH 3 (s) ) of greater than 1.

6. The method as claimed in claim 1 , wherein the separation of the liquid and solid phases is performed by filtration or by centrifugation.

7. The method as claimed in claim 1 , wherein the ammonia is removed from said recovered liquid phase by evaporation.

8. The method as claimed in claim 1 , wherein said separation is performed on conclusion of said bringing into contact, after stopping said stream.

9. The method as claimed in claim 1 , wherein said separation is performed during said bringing into contact.

10. The method as claimed in claim 9 , wherein said solid borazane (NH 3 BH 3 (s) ), placed on a filter, is brought into contact with a stream of ammonia gas (NH 3 (g) ) and wherein the liquid phase generated is recovered below said filter whereas the solid phase is retained by said filter.

11. The method as claimed in claim 1 , wherein the gaseous ammonia (NH 3 (g) ) is used in a gaseous ammonia/solid borazane (R═NH 3 (g) /NH 3 BH 3 (s) ) mole ratio between 5 and 15.

12. The method as claimed in claim 6 , wherein the separation of the liquid and solid phases is performed by filtration.

Assignees

• Arianegroup Sas

Inventors

• Vandecandelaere Nicolas
• Dubois Valentin

Classifications

• C01B35/14

  Compounds containing boron and nitrogen, phosphorus, sulfur, selenium or tellurium · CPC title

• C01B35/146 Primary

  Compounds containing boron and nitrogen, e.g. borazoles (ammonium tetrafluoborates C01B35/063; ammonium borates C01B35/12) · CPC title

• C01P2002/86

  by NMR- or ESR-data · CPC title

• C01P2002/88

  by thermal analysis data, e.g. TGA, DTA, DSC · CPC title