Processes for synthesizing borohydride compounds

• US 20030003038A1
• Filed: 04/12/2001
• Published: 01/02/2003
• Est. Priority Date: 04/12/2001
• Status: Active Grant

• Current Assignee: Millennium Cell Inc.
• Original Assignee: Millennium Cell Inc.
• Inventors: Kelly, Michael T., Wu, Ying, Amendola, Steven C.
• Granted Patent: US 6,524,542 B2
• Time in Patent Office: Days
• US Class Current: 423/286
• CPC Class Codes: C01B 6/13 Addition complexes of monoborane or diborane, e.g. with phosphine, arsine or hydrazine
• CPC Class Codes: C01B 6/19 Preparation from other compounds of boron
• CPC Class Codes: C01B 6/21 Preparation of borohydrides of alkali metals, alkaline earth metals, magnesium or beryllium; Addition complexes thereof, e.g. LiBH4.2N2H4, NaB2H7
• CPC Class Codes: F17C 11/005 for hydrogen
• CPC Class Codes: Y02P 20/582 Recycling of unreacted starting or intermediate materials

Abstract

Pocesses for synthesizing borohydride compounds with reduced energy requirements are disclosed.

Claims

1. A process for producing borohydride compounds, which comprises:

(A) reacting carbon dioxide and water with a metaborate compound of formula YBO₂, where Y is a monovalent cationic moiety, thereby providing YHCO₃ and B₂O₃;

(B) converting the YHCO₃ into Y₂O, carbon dioxide, and water;

(C) reacting the B₂O₃ with carbon and a halide compound of formula X₂ to obtain BX₃ and carbon monoxide, wherein X is selected from the group consisting of F, Cl, Br, I, and At;

(D) reacting the BX₃ with hydrogen to obtain B₂H₆ and HX; and

(E) reacting the Y₂O with B₂H₆ to obtain YBH₄ and YBO₂,

2. The process according to claim 1, wherein Y is selected from the group consisting of the alkali metals, pseudo-alkali metals, an ammonium ion, quaternary amines of formula NR₄⁺, and a mixture thereof, and wherein R is independently hydrogen, straight or branched C₁ to C₄ alkyl group, or a mixture thereof.

3. The process according to claim 2, wherein Y is selected from the group consisting of Li, Na, K, Rb, Cs, Fr, NH₄⁺, Tl, and quaternary amines of formula NR₄⁺, wherein R is independently selected from hydrogen and straight or branched C₁ to C₄ alkyl group.

4. The process according to claim 3, wherein Y is selected from the group consisting of Na, Li, and K.

5. The process according to claim 1, wherein the BX₃ of step (D) is hydrogenated with an aldehyde selected from the group consisting of formaldehyde, benzaldehyde, acetaldehyde, and mixtures thereof.

6. The process according to claim 1, wherein the YBO₂ produced in step (E) is recycled for use in step (A).

7. The process according to claim 1, wherein the carbon dioxide produced in step (B) is recycled for use in step (A).

8. The process according to claim 1, wherein the water produced in step (B) is recycled for use in step (A).

18. The process according to claim 1, wherein the BX₃ of step (D) is reacted with a silicon hydride to obtain diborane and SiX₄.

20. A borohydride compound obtained by the process according to claim 1.

9. A process for producing borohydride compounds, which comprises:

(A) reacting carbon dioxide and water with a metaborate compound of formula YBO₂, where Y is a monovalent cationic moiety, thereby providing YHCO₃ and B₂O₃;

(B) converting the YHCO₃ into Y₂CO₃, carbon dioxide, and water;

(C) reacting the B₂O₃ with elemental carbon and an X-containing compound of formula X₂ to obtain BX₃ and carbon monoxide, wherein X is selected from the group consisting of F, Cl, Br, I, and At;

(D) reacting the BX₃ with hydrogen to obtain B₂H₆ and HX; and

(E) reacting the Y₂CO₃ with B₂H₆ to obtain YBH₄, YBO₂, and carbon dioxide.

10. The process according to claim 9, wherein Y is selected from the group consisting of the alkali metals, pseudo-alkali metals, an ammonium ion, quaternary amines of formula NR₄⁺, and a mixture thereof, R is independently hydrogen, straight or branched C₁ to C₄ alkyl group, or a mixture thereof.

11. The process according to claim 9, wherein Y is selected from the group consisting of Li, Na, K, Rb, Cs, Fr, NH₄⁺, Tl, and quaternary amines of formula NR₄⁺, wherein R is independently selected from hydrogen and straight or branched C₁ to C₄ alkyl group.

12. The process according to claim 9, wherein Y is selected from the group consisting of Na, Li, and K.

13. The process according to claim 9, wherein the BX₃ of step (D) is hydrogenated with an aldehyde.

14. The process according to claim 13, wherein the aldehyde is selected from the group consisting of formaldehyde, benzaldehyde, acetaldehyde, and mixtures thereof.

15. The process according to claim 9, wherein the YBO₂ produced in step (E) is recycled for use in step (A).

16. The process according to claim 9, wherein the carbon produced in steps (B) and (E) is recycled for use in step (A).

17. The process according to claim 9, wherein the water produced in step (B) is recycled for use in step (A).

19. The process according to claim 9, wherein the BX₃ of step (D) is reacted with a silicon hydride to obtain diborane and SiX₄.

21. A borohydride compound obtained by the process according to claim 9.