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Sodium dodecyl sulfate (SDS) markedly improved tetrahydrofuran (THF) - assisted methane hydrate formation. Firstly, methane hydrate formation with different THF amount, 1, 3, and 5.56 mol%, was studied. SDS with 1, 4, and 8 mM was then investigated for its roles on the methane hydrate formation with and without THF. The experiments were conducted in a quiescent condition in a fixed volume crystallizer at 8 MPa and 4°C. The results showed that almost all studied THF and SDS concentrations enhanced the methane hydrate formation kinetics and methane consumption compared to that without the promoters, except 1 mol% THF. Although, with 1 mol% THF, there were no hydrates formed for 48 hours, the addition of just 1 mM SDS surprisingly promoted the hydrate formation with a significant increased in the kinetics. This prompts the use of methane hydrate technology for natural gas storage application with minimal promoters.

Hydrogen desorption/absorption of the LiBH 4 / MgH 2 mixture milled for 5 h was investigated with different initial pressures. The results showed that the initial pressure played an important role in the reversibility of the LiBH 4 /MgH 2 mixture. The stability of the hydrogen capacity in the subsequent desorption was improved with a higher initial pressure. A possible reason was from the increase in the formation of MgB 2 and the lower degree in the decomposition of both LiBH 4 to the amorphous phases of Li 2 B 12 H 12 and B; and MgH 2 to Mg, during the hydrogen desorption. However, the higher initial pressure increased the hydrogen desorption temperature. The desorption temperature was increased from 310°C for the sample decomposing under 0.1 MPa hydrogen pressure to 360°C for other cases. This may be due to the higher energy required to overcome the suppression of MgH 2 and LiBH 4 decomposition.

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