چكيده لاتين
Today, many issues, including environmental issues, have led to a lot of effort by researchers to separate gaseous pollutants using different methods. Membrane technology is one of these methods. In recent years, in many computational and experimental researches, the design of suitable membranes for gas separation has been considered due to lower energy consumption and higher performance. Various studies have been conducted on graphene membranes in order to use them in the separation and better selectivity of gases. In this research, a nano-membrane with a graphene sheet was designed, and the separation of carbon dioxide, oxygen and methane gases was investigated using the computational method of molecular dynamics simulation. In order to design a suitable membrane, we create holes in the membrane and investigate the effect of hole radius, hole location, membrane orientation, number of membranes, and the effect of temperature on the separation of gases used in the simulation. It was observed that by increasing the radius of the holes, after balancing the system at a temperature of 300 K and applying a pressure of 5000 pascal on the piston, the gas permeability increases. In addition, by increasing the number of membranes to two membranes with a layer distance of 3.5 angstroms, we investigated the effect of displacement distance of two holes in the membranes. The obtained results show that the performance of gas separation is improved by increasing the number of membranes. Also, in the displacement distance of 0 angstroms, the best efficiency is related to the membrane with a cavity radius of 4.0 angstroms, and in the displacement distance of 1.5 angstroms, it corresponds to the membrane with a cavity radius of 4.5 angstroms. By changing the orientation of the membrane from the z direction to the y direction, the oxygen gas separation process has a better performance. In investigating the effect of temperature change, we changed the temperature of a number of systems from 300 K to 270 and 330 K and noticed a decrease in separation performance at these temperatures. Therefore, in general, it can be said that the best temperature for separation is observed at 300 K.
