PRODUCTION, HYDROLYSIS AND APPLICATIONS OF SODIUM BOROHYDRIDE

Abstract

In this study, technologically and economically more effective sodium borohydride (SBH) synthesis process in a single step without using expensive sodium metal from anhydrous borax was developed. In a autoclave type fixed bed reactor (V=1000cm(3)), the effect of process parameters including reaction temperature, reaction time and hydrogen pressure on SBH efficiency was investigated. Optimum synthesis conditions were stated as T=550-560 degrees C, P-H2=40-50 bar and t=4-6 hours. In these conditions, the production efficiency of SBH was found to be 85-90% by mole and 97-99 % in purity. It was observed that SBH efficiency depends on synthesis conditions whereas its purity is not. Besides, technological principles of process were developed. Different effective homogeneous and inexpensive heterogeneous catalysts without using Pt, Ru, etc. for the hydrolysis of SBH were developed. Homogeneous (liquid) catalysts were more active compared to solid catalysts at the same conditions. The effects of temperature, concentrations of both SBH and NaOH on hydrolysis reaction were studied. Different principles for SBH hydrolysis were investigated to apply for fuel cells