| Summary: | 碩士 === 國立中央大學 === 材料科學與工程研究所 === 101 === In this research, the hydrogen storage alloys of tow-stage compresser are prepared by arc-melting. There are La0.6Ce0.4Ni5+x (x=0~3) serious alloys and Ti0.9Zr0.1Mn0.9-yCr0.9-yNi0.2+2y(y=0,0.1) serious alloys, which will be used in first-atage and second-stage hydrogen thermal compressers respectively. The results show up that the pressure of hydrogen gas can be compressed from 35atm to 400atm under 100℃.
The La-based hydrogen storage alloy be used in the first-stage hydrogen thermal compresser is La0.6Ce0.4Ni6. By the substitution of Ce, the volume of the crystal unit cell is shrinkaged. In addition to the boundary effect of extra Ni priciptation will lift the adsorption and desorption plateau powerfully. Through first-stage compression, the commercial hydrogen gas can be compressed from 35atm(20℃) to 120atm(100℃). This La0.6Ce0.4Ni6 alloy, used in the first-stage hydrogen compresser, has medium hydrogen-storage quantity(1.05wt%)、high desorption plateau(26atm) and low hystersis effect(0.34).
And the Ti-based hydrogen storage alloy used in the second-stage hydrogen thermal compresser is Ti0.9Zr0.1Mn0.8Cr0.8Ni0.4. By the Ni substitution of larger atoms such as Mn and Cr, the volume of the crystal unit cell will shrinkage lightly and lead the plateau pressure higher. The hydrogen gas produced from first-stage compresser can be compressed from 77atm(20℃) to 400atm(100℃). This Ti0.9Zr0.1Mn0.8Cr0.8Ni0.4 alloy has advantages such as high desorption plateau(42.81atm)、high compression ratio(5.3) and low hysteresis effect(0.32).
The two systems of alloys have their own characteristics and advantages, the La based alloys can adsorb hydrogen stably and quickly under low pressure, and desorb hydeogen more completely at high temperature, so that choose this serious alloys to be the material of first-stage hydrogen compresser. The Ti based alloys have high desorption plateau and small hysteresis, and suitable to adsorb hydrogen gas quickly under relative high pressure. In addition to shorten the hydration time of the second stage and improve the efficiency to supply 400atm high pressure hydrogen gas under 100℃.
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