Hydrogen Production And Application Technology Of Micro Hydrogen Generator Based On NaBH₄ Hydrolysis

With the rapid development of human society,the world’s demand for energy continues to grow.The primary energy used by humans has shifted from non-renewable energy such as fossil fuels to renewable energy such as solar energy and wind power.However,these renewable energy sources usually lack the means of conversion,storage,and recovery.As the secondary energy,hydrogen energy provides an efficient way for the conversion and storage of primary energy,chemical energy,and electricity.With the study of hydrogen energy in recent years,the storage and rapid release of hydrogen energy has also become a star subject.As a way of chemical hydrogen storage,sodium borohydride(Na BH4)has received extensive attention due to its high hydrogen storage,easy hydrogen release,and relatively stable chemical properties.Based on the theory of Na BH4 hydrolysis,the catalyst for Na BH4 hydrolysis was prepared.The hydrogen generation and purification system is designed and its hydrogen production efficiency and purity were investigated.Finally,it was applied to the 50-80 W class integrated fuel cell system for application.In this dissertation,firstly,from the principle of hydrolysis of Na BH4,a catalyst for the hydrolysis of Na BH4 alkaline solution was prepared.The catalyst was prepared by the method of impregnation and reduction.The amorphous Co-B-P was an effective catalytic component,and the foam nickel was used as the substrate.This article also conducted a preliminary test on the catalytic efficiency of different loadings of Co-BP/Foam Ni catalysts.When catalyzed by 15wt% Na BH4 solution,the catalyst with a loading rate of 43% has a maximum catalytic rate of 240 ml/min per square centimeter(Reaction temperature 75 °C).After that,the structure design and performance of the hydrogen generation and purification system were investigated.Structurally,the hydrogen generator is a gasliquid separation structure inside and outside chamber,and the purification device is a reflux pipe,heat sink,reflux pipe,absorber four-level structure.In terms of performance,the hydrogen generator can be loaded with 66cm2 of the above-mentioned catalyst with a loading rate of 43%.The catalytic conversion is over 85% for 15 wt% Na BH4 solution with flow rate not exceeding 6 ml/min and supply a continuous hydrogen rate of 1800 ml/min.The catalyst is used for 40 times and the load rate is still above 35%.The cooling device of the purification device can condense more than 90% of the alkalicontaining vapor,and rely on the periodic reflux of hydrogen pressure,the consumption of the absorbent is up to 5g/hour.The impurities in the hydrogen are completely removed.Hydrogen can be used by the fuel cell system for a long time.Finally,this paper designs the control of the miniaturized fuel cell system,and applies the above-mentioned hydrogen generator to perform a comprehensive performance test.The optimum working pressure of the fuel cell is 50-70 k Pa.The working temperature should not exceed 50°C for a long time.The fuel cell system has a net weight of 2.2kg,a maximum output power of 82 W,a corresponding output voltage of 12 V,an energy density of up to 353Wh/kg,and no significant degradation in performance during 9 hours of continuous work.A fuel cell system integration of more than 50 W has been finished and it has practical application value.