Nanocrystalline MgH2 and MgH2-based composites with 25%(mass fraction) of Al, Ca, or CaH2 as an individual additive respectively were prepared by ball milling. The crystallite size and morphology of the as-milled po...Nanocrystalline MgH2 and MgH2-based composites with 25%(mass fraction) of Al, Ca, or CaH2 as an individual additive respectively were prepared by ball milling. The crystallite size and morphology of the as-milled powders were characterized and their hydrolysis behaviours were investigated in comparison with commercial polycrystalline MgH2. The results show that the crystallite size of both MgH2 and MgH2-based composites is reduced to less than 13nm after milling for 15h. Due to its enhanced specific surface area and unique nanocrystalline structure, the as-milled MgH2 shows much better hydrolysis kinetics than the commercial polycrystalline MgH2, with the hydrolysed fraction upon hydrolysing for 70min enhances from 7.5% to about 25%. As compared with the as-milled MgH2, the MgH2-based composites with either CaH2 or Ca as an additive present further greatly improved hydrolysis kinetics, with the hydrolysed fraction for 80min achieving about 76% and 62% respectively. However, the addition of Al doesn’t show any positive effect on the improvement of the hydrolysis kinetics of MgH2.展开更多
The best mix scenario by renewable energy and fossil fuel with or without CCS(Carbon Dioxide Capture and Storage) would be a solution to compromise Greenhouse Gases emission issue caused by carbon dioxide(CO2),and dep...The best mix scenario by renewable energy and fossil fuel with or without CCS(Carbon Dioxide Capture and Storage) would be a solution to compromise Greenhouse Gases emission issue caused by carbon dioxide(CO2),and depletion of crude oil and natural gas reserves.As fossil fuel with pre-combustion CCS means hydrogen manufacturing and also hydrogen can be produced via electrolysis with renewable energy,it is desirable to establish transportation and storage systems of hydrogen as a clean energy.In this paper a vision on Hydrogen Supply Chain by Organic Chemical Hydride(OCH) Method as well as comparison of CCS configuration are discussed.展开更多
文摘Nanocrystalline MgH2 and MgH2-based composites with 25%(mass fraction) of Al, Ca, or CaH2 as an individual additive respectively were prepared by ball milling. The crystallite size and morphology of the as-milled powders were characterized and their hydrolysis behaviours were investigated in comparison with commercial polycrystalline MgH2. The results show that the crystallite size of both MgH2 and MgH2-based composites is reduced to less than 13nm after milling for 15h. Due to its enhanced specific surface area and unique nanocrystalline structure, the as-milled MgH2 shows much better hydrolysis kinetics than the commercial polycrystalline MgH2, with the hydrolysed fraction upon hydrolysing for 70min enhances from 7.5% to about 25%. As compared with the as-milled MgH2, the MgH2-based composites with either CaH2 or Ca as an additive present further greatly improved hydrolysis kinetics, with the hydrolysed fraction for 80min achieving about 76% and 62% respectively. However, the addition of Al doesn’t show any positive effect on the improvement of the hydrolysis kinetics of MgH2.
文摘The best mix scenario by renewable energy and fossil fuel with or without CCS(Carbon Dioxide Capture and Storage) would be a solution to compromise Greenhouse Gases emission issue caused by carbon dioxide(CO2),and depletion of crude oil and natural gas reserves.As fossil fuel with pre-combustion CCS means hydrogen manufacturing and also hydrogen can be produced via electrolysis with renewable energy,it is desirable to establish transportation and storage systems of hydrogen as a clean energy.In this paper a vision on Hydrogen Supply Chain by Organic Chemical Hydride(OCH) Method as well as comparison of CCS configuration are discussed.