Ammonia borane purification method
AssigneesBoroscience International, Inc., WeylChem Sustainable Materials, LLC
InventorsBernard Franklin Spielvogel, Kevin Joel Drost
Life of this patent
Estimating the term…
Abstract
A method of purifying ammonia borane is provided whereby crude ammonia borane is dissolved in a basic aqueous solution, the solution is heated to decompose and precipitate impurities found in the crude ammonia borane, and the impurities are separated by filtration. The aqueous solution containing dissolved ammonia borane is then cooled to a temperature of from 10° C. to −10° C., to precipitate the ammonia borane, which is recovered and dried to yield a high-purity product.
Claims32
A method of purifying crude ammonia borane, comprising the steps of:
- (a) forming an aqueous solution of crude ammonia borane in a basic aqueous solvent;
- (b) heating the aqueous solution to decompose and precipitate impurities present in the crude ammonia borane;
- (c) separating the precipitated impurities from the aqueous solution;
- (d) cooling the aqueous solution to decrease the solubility of the ammonia borane in the basic aqueous solvent, whereby a portion of ammonia borane is no longer dissolved in the basic aqueous solvent;
- and
- (e) separating the aqueous solution from the portion of ammonia borane that is no longer dissolved in the basic aqueous solvent.
A method of purifying crude ammonia borane, comprising the steps of:
- (a) dissolving crude ammonia borane in a basic aqueous solvent to form an aqueous solution;
- (b) heating the aqueous solution to decompose and precipitate impurities present in the crude ammonia borane;
- (c) separating the precipitated impurities from the aqueous solution;
- (d) cooling the aqueous solution to decrease the solubility of the ammonia borane in the basic aqueous solvent, whereby a portion of ammonia borane is precipitated;
- and
- (e) separating the aqueous solution from the portion of ammonia borane that has precipitated.
A method of purifying crude ammonia borane, comprising the steps of:
- (a) forming an aqueous solution of crude ammonia borane in a basic aqueous solvent by adding the basic aqueous solvent to a solution of the crude ammonia borane in an organic liquid, whereby the formation of the aqueous solution is conducted at a temperature at which the solubility of the ammonia borane is greater in the basic aqueous solvent than in the organic liquid, and wherein the basic aqueous solvent and the organic liquid form a two-phase system;
- (b) heating the aqueous solution to decompose and precipitate impurities present in the crude ammonia borane;
- (c) separating the precipitated impurities from the aqueous solution and organic liquid;
- (d) cooling the aqueous solution and organic liquid to decrease the solubility of the ammonia borane in the basic aqueous solvent, whereby a portion of the ammonia borane is caused to partition back into the organic liquid;
- (e) separating the aqueous solution from the organic liquid;
- and
- (f) evaporating the organic liquid to recover ammonia borane.
Dependencies are inferred from the claim text.