Innovation in sodium borohydride production process from borosilicate glass with sodium under hydrogen atmosphere: “high pressure process”

This paper presents a new process for producing sodium borohydride ( NaBH 4 ) , which can be used as a hydrogen storage medium. The process is based on the conversion reaction of borosilicate glass at temperatures between about 400 and 500 ∘ C under high hydrogen pressure of 22 atm . For this purpose, borax ( Na 2 B 4 O 7 ) is sintered with quartz powder ( SiO 2 ) to obtain borosilicate glass then heated with metallic sodium (Na) under high hydrogen pressure. Furthermore, a study of the hydrogenation characteristics of borosilicate glass has been made using change in hydrogen pressure drop as function of reaction time in the process. It is concluded that the required hydrogenation time is 70 min at 475 ∘ C under 22 atm of hydrogen pressure for production of NaBH 4 with excellent yield.