Regenerating deuterium absorption of Ti_(36)Zr_(40)Ni_(20)Pd_4 icosahedral quasicrystal

Ti/Zr-based icosahedral quasicrystals are a kind of promising hydrogen storage ma- terials, however their absorption regeneration after oxidation-poisoning has been scarcely studied. This work is intended to investigate the deuterium-storage re- generation of a suction-cast Ti36Zr40Ni20Pd4 quasicrystal. It was found that only through hot vacuuming the quasicrystal could be refreshed from air-flow poisoning to absorb deuterium in two cycles. During the first absorption course, a pregnancy period was observed before the real deuterium uptake while deuterium was loaded rapidly during the second one. The deuterium concentration in the alloy can reach 0.011 mol.D2/（g.M） （corresponding to a hydrogen mass percent of 2.2%. D2 and M denote molecular deuterium and the metallic alloy）. But the loaded deuterium was very difficult to release completely even by eight-stage desorption at different tem- peratures. After the second desorption, the quasicrystal phase remained in a small volume, as though the desorption temperature was beyond the crystallization temperature of the quasicrystal. This probably is attributed to the solution function of residual deuterium in the alloy.

Absorption and recovery of n-hexane in aqueous solutions of fluorocarbon surfactants

n-Hexane is widely used in industrial production as an organic solvent. As an industrial exhaust gas, the contribution of n-hexane to air pollution and damage to human health are attracting increasing attention. In the present study, aqueous solutions of two fluorocarbon surfactants（FSN100 and FSO100） were investigated for their properties of solubilization and dynamic absorption of n-hexane, as well as their capacity for regeneration and n-hexane recovery by thermal distillation. The results show that the two fluorocarbon surfactants enhance dissolution and absorption of n-hexane, and their effectiveness is closely related to their concentrations in solution. For low concentration solutions（0.01%–0.30%）, the partition coefficient decreases dramatically and the saturation capacity increases significantly with increasing concentration, but the changes for both are more modest when the concentration is over 0.30%. The FSO100 solution presents a smaller partition coefficient and a greater saturation capacity than the FSN100 solution at the same concentration,indicating a stronger solubilization for n-hexane. Thermal distillation is a feasible method to recover n-hexane from these absorption solutions, and to regenerate them. With 90 sec heating at 80–85°C, the recovery of n-hexane ranges between 81% and 85%, and the regenerated absorption solution maintains its original performance during reuse. This study provides basic information on two fluorocarbon surfactants for application in the treatment of industrial n-hexane waste gases.