Molecular simulations of supercritical fluid permeation through disordered microporous carbons.
نویسندگان
چکیده
Fluid transport through microporous carbon-based materials is inherent in numerous applications, ranging from gas separation by carbon molecular sieves to natural gas production from coal seams and gas shales. The present study investigates the steady-state permeation of supercritical methane in response to a constant cross-membrane pressure drop. We performed dual control volume grand canonical molecular dynamics (DCV-GCMD) simulations to mimic the conditions of actual permeation experiments. To overcome arbitrary assumptions regarding the investigated porous structures, the membranes were modeled after the CS1000a and CS1000 molecular models, which are representative of real microporous carbon materials. When adsorption-induced molecular trapping (AIMT) mechanisms are negligible, we show that the permeability of the microporous material, although not significantly sensitive to the pressure gradient, monotonically decreases with temperature and reservoir pressures, consistent with diffusion theory. However, when AIMT occurs, the permeability increases with temperature in agreement with experimental data found in the literature.
منابع مشابه
In Silico Determination of Gas Permeabilities by Non-Equilibrium Molecular Dynamics: CO2 and He through PIM-1
We study the permeation dynamics of helium and carbon dioxide through an atomistically detailed model of a polymer of intrinsic microporosity, PIM-1, via non-equilibrium molecular dynamics (NEMD) simulations. This work presents the first explicit molecular modeling of gas permeation through a high free-volume polymer sample, and it demonstrates how permeability and solubility can be obtained co...
متن کاملApplicability of molecular simulations for modelling the adsorption of the greenhouse gas CF4 on carbons.
Tetrafluoromethane, CF(4), is a powerful greenhouse gas, and the possibility of storing it in microporous carbon has been widely studied. In this paper we show, for the first time, that the results of molecular simulations can be very helpful in the study of CF(4) adsorption. Moreover, experimental data fit to the results collected from simulations. We explain the meaning of the empirical param...
متن کاملAdsorption-induced deformation of microporous carbons: pore size distribution effect.
We present a thermodynamic model of adsorption-induced deformation of microporous carbons. The model represents the carbon structure as a macroscopically isotropic disordered three-dimensional medium composed of stacks of slit-shaped pores of different sizes embedded in an incompressible amorphous matrix. Adsorption stress in pores is calculated by means of Monte Carlo simulations. The proposed...
متن کاملThe adsorption behaviour of CH4 on microporous carbons: effects of surface heterogeneity.
The effects of chemical and structural surface heterogeneity on the CH4 adsorption behaviour on microporous carbons have been investigated using a hybrid theoretical approach, including the use of density functional theory (DFT), molecular dynamics (MD), and grand canonical Monte Carlo (GCMC) simulations. Bader charge analysis is first performed to analyze the surface atomic partial charges. Th...
متن کاملMolecular Dynamics Simulation on Permeation of Acetone/Nitrogen Mixed Gas through Al2O3 Microporous Membranes
In this work, molecular dynamics (MD) was performed to simulate the dynamic processes of 1:4 acetone/nitrogen permeating through different Al2O3 membranes by Materials Studio 2.2 software package. Three modeling systems were constructed applying different modeling box lengths as well as different hollow size and texture of Al2O3 membranes to compare different permeation behaviors. In each syste...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Langmuir : the ACS journal of surfaces and colloids
دوره 29 32 شماره
صفحات -
تاریخ انتشار 2013