Cheng Xu, Li Zhigang, He Ya-Ling
Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong
Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University Xi'an Shaanxi 710049 PR China
RSC Adv. 2020 Oct 12;10(61):37507-37514. doi: 10.1039/d0ra07506j. eCollection 2020 Oct 7.
In this work, the effects of external pressure on the release of methane through zeolite nanochannels are studied through molecular dynamics (MD) simulations. The release percentage of methane under three types of pressure loadings with various strengths and frequencies are obtained. Specifically, constant, sawtooth-shaped, and sinusoidal pressures are examined. As the pressure strength is increased, it is found that the release percentage first decreases and then increases significantly before finally approaching a constant. At sufficiently high pressures, the release percentage of methane under constant external pressure is about 65%, while it reaches over 90% for sawtooth-shaped and sinusoidal pressures. The loading frequency for periodic external pressures appears to be unimportant compared with the effect of the pressure strength. Theoretical predictions of the release percentage are made on the basis of the kinetic energy of methane molecules and the energy barrier inside the nanochannels, which are in good agreement with MD simulations.
在这项工作中，通过分子动力学（MD）模拟研究了外部压力对甲烷通过沸石纳米通道释放的影响。获得了在三种不同强度和频率的压力载荷下甲烷的释放百分比。具体而言，研究了恒定压力、锯齿形压力和正弦压力。随着压力强度的增加，发现释放百分比首先下降，然后显著增加，最终趋于恒定。在足够高的压力下，恒定外部压力下甲烷的释放百分比约为65%，而锯齿形和正弦压力下则超过90%。与压力强度的影响相比，周期性外部压力的加载频率似乎并不重要。基于甲烷分子的动能和纳米通道内部的能垒对释放百分比进行了理论预测，结果与分子动力学模拟结果吻合良好。
