Synthesis of sodium aluminum hydride

In a process for the preparation of sodium aluminum tetrahydride wherein reaction is effected among sodium, aluminum and hydrogen at an elevated temperature and pressure in a glycol dialkyl ether reaction medium in which the sodium aluminum tetrahydride is soluble and wherein the reaction is performed in a semi-continuous manner whereby in successive runs the reaction is initiated by use of an aluminum-containing heel from the prior run, the improvement wherein the ether reaction medium employed in at least the initial run initially contains up to 3 mole percent of water or up to 10 mole percent of an alcohol or both sufficient to promote initiation of the reaction so as to significantly shorten the induction period that would otherwise be experienced under the same conditions when using said liquid reaction medium in pre-dried, alcohol-free form.

In a process for the preparation of sodium aluminum tetrahydride wherein reaction is effected among sodium, aluminum and hydrogen at an elevated temperature and pressure in a liquid glycol dialkyl ether reaction medium in which the sodium aluminum tetrahydride is soluble and wherein the reaction is performed in a semi-continuous manner whereby in successive runs the reaction is initiated by use of an aluminum-containing heel from the prior run, the improvement wherein the ether reaction medium employed in the initial run and in at least some of the successive runs initially contains up to 3 mole percent of water or up to 10 mole percent of an alcohol or both sufficient to promote initiation of the reaction so as to significantly shorten the induction period that would otherwise be experienced under the same conditions when using said liquid reaction medium in pre-dried, alcohol-free form.

In a process for the preparation of sodium aluminum tetrahydride by reaction of sodium, aluminum and hydrogen at an elevated temperature and pressure in a liquid reaction medium, the improvement wherein the liquid reaction medium is a glycol dialkyl ether and initially contains up to 10 mole percent of isopropanol sufficient to promote initiation of the reaction so as to significantly shorten the induction period that would otherwise be experienced under the same conditions when using said liquid reaction medium in pre-dried, alcohol-free form.