4 Results and Discussion: Fluid Transport

4.1 Fluid Transport in HH Nanopores

In this section, we report on the hydrocarbon and water velocity profiles with different accelerations (0.0005, 0.001, and 0.002 nm/ps2) at 350 K and 400 atm. This would be analogous to imposing advective flow on the fluid confined within the pores. The velocity profile is obtained applying the bin method91which is shown in Supporting Information.
We present the water (Fig. 7a) and hydrocarbon (Fig. 7b) velocity profiles at 0.0005 nm/ps2 in the 5 nm HH nanopore. Because the hydrocarbon and water velocity profiles at the acceleration of 0.001 nm/ps2 and 0.002 nm/ps2show similar trends with that of 0.0005 nm/ps2, they are not shown here and provided in Fig.S4 in Supporting Information.
Fig. 7a indicates that the water velocity changes with increasing water concentration directly as a result of the growth in the thickness of the adsorbed layer of water as shown in Fig. 8. A thicker adsorbed layer impedes flow. At 100% water, we observe the classical parabolic signature of liquid flow in slit-pores.
Fig. 7b indicates that increasing water concentration promotes hydrocarbon flow up to a point. The initial increase has been attributed to the creation of smooth surfaces following adsorption of water69. Subsequent increases decrease the effective flow radius for hydrocarbon flow as shown in Fig. 8, leading to a decline of hydrocarbon velocity.