Process for production of sodium borohydride from sodium aluminum hydride with recycle of byproducts
A process for production of sodium borohydride. The process comprises the steps of: (a) combining a boric acid ester, B(OR) 3 and sodium aluminum hydride to produce sodium borohydride and Al(OR) 3 ; and (b) combining Al(OR) 3 and sulfuric acid to produce alum and ROH.
1. A process for production of sodium borohydride; said process comprising steps of:
(a) combining a boric acid ester precursor and an alcohol, ROH; wherein R represents alkyl having at least three carbon atoms, aryl or aralkyl; to produce a boric acid ester, B(OR) 3 ;
(b) combining sodium, aluminum and hydrogen to produce sodium aluminum hydride;
(c) combining the boric acid ester and the sodium aluminum hydride to produce sodium borohydride and Al(OR) 3 and separating sodium borohydride and Al(OR) 3 by dissolving Al(OR) 3 in a hydrocarbon solvent; and
(d) combining the Al(OR) 3 produced in step (c) and sulfuric acid to produce alum and ROH; wherein ROH produced in step (d) is recycled to step (a).
2. The process of claim 1 in which R is phenyl.