  Efficient and sustainable techniques for separating water-methanol mixtures
are in high demand in the industry. Recent studies have revealed that membranes
and 2D materials could achieve such separation. In our research, we explore the
impact of a nanoconfining graphene slit-pore on the dynamics and structure of
water-methanol mixtures. By Molecular Dynamics simulations of a coarse-grained
model for water mixtures containing up to 25% methanol, we show that, for
appropriate pore sizes, water tends to occupy the center of the pore. In
contrast, methanol's apolar moiety accumulates near the hydrophobic walls.
Additionally, modifying the pore's width leads to a non-monotonic change in the
diffusivity of each component. However, water always diffuses faster than
methanol, implying that it should be possible to identify an optimal
configuration for water-methanol separation based on physical mechanisms. Our
calculations indicate that one of the more effective pore sizes, 12.5{\AA}, is
also mechanically stable, minimizing the energy cost of a possible filtering
membrane.
