(30b) Hydrogen Storage Via Sodium Borohydride/Metaborate Recycling

A patent-pending process will allow us to perform low-cost recycling of sodium metaborate into sodium borohydride by adding four moles of hydrogen gas per each mole of sodium metaborate. This process permits us to avoid the high cost associated with the Brown-Schlessinger process. In our process, the primary cost is the cost of producing hydrogen via electrolysis of water using photovoltaic electricity, which is the primary business of 21-Century Silicon, Inc.

Thirteen metallic catalysts are able to produce sodium borohydride from sodium metaborate and hydrogen. Only 321 KJ/mol of endothermic change of Gibb's free energy occurs. The reaction is carried out using high pressure plasma. Water formed during the reaction is captured by metallic oxides to suppress the reverse reaction. Vacuum distillation of sodium borohydride is carried out afterwards.