Chemical Engineering Department, New Mexico State University, Las Cruces, New Mexico 88003, USA.
Langmuir. 2010 Jun 1;26(11):8414-8. doi: 10.1021/la904857e.
Porous media were used to control the hydrogen clathrate particle size in order to accelerate its formation kinetics. Stoichiometric tetrahydrofuran-hydrogen binary clathrate hydrates with approximately 1 wt % hydrogen loading formed in the mesopores of four porous media with median pore diameters of 49, 65, 100, and 226 A at 270 K and hydrogen pressure of 65 bar. The minimum formation time for the tetrahydrofuran-hydrogen binary clathrate hydrates was 27 min in a porous medium with a median pore diameter of 49 A, which is 6-22 times faster than the tetrahydrofuran-hydrogen binary clathrate hydrates formed in the bulk ice. The clathrate formation time was found to increase with pore size of the porous media. A modified shrinking core kinetic model was used to calculate the diffusivity of hydrogen in the tetrahydrofuran-hydrogen binary clathrate hydrates. Hydrogen diffusivities in the tetrahydrofuran-hydrogen binary clathrate hydrates were found to be on the order of 10(-18)-10(-19) m(2)/s and decrease with increasing pore size or clathrate particle size.
多孔介质被用于控制氢笼形化合物颗粒的大小，以加速其成核动力学。在 270 K 和 65 巴的氢气压力下，四种中值孔径分别为 49、65、100 和 226 Å 的多孔介质中形成了具有约 1wt%氢气负载量的计量四氢呋喃-氢气二元笼形水合物。在中值孔径为 49 Å 的多孔介质中，四氢呋喃-氢气二元笼形水合物的最小形成时间为 27 分钟，这比在块状冰中形成的四氢呋喃-氢气二元笼形水合物快 6-22 倍。发现笼形物形成时间随多孔介质的孔径而增加。采用改进的收缩核动力学模型计算了氢在四氢呋喃-氢气二元笼形水合物中的扩散系数。发现氢在四氢呋喃-氢气二元笼形水合物中的扩散系数约为 10(-18)-10(-19) m(2)/s，并随孔径或笼形物颗粒尺寸的增大而减小。
