Diffusion Analysis of Flue Gases Through Carbon Nanotube- and Graphene-Reinforced PEBAX Nanocomposite Membranes: A Molecular Dynamic Study †

Dependency on fossil fuels for global energy demand has led to an increase in the concentration of CO₂ in the atmosphere, thereby contributing to environmental challenges such as climate change, rise in atmospheric temperature, etc. Since the major contributions of CO₂ emissions are from industries, capturing CO₂ from post-combustion flue gas has become the focus of many research communities. As such, membrane-based carbon capture and storage (CCS) is an important pathway for controlling CO₂ emissions. However, performance validation for membrane separation is required to find the best composite material with a high diffusion rate. Hence, the objectives of this research included determining the performance of the nanocomposite membranes comprising polyether-block-amide (PEBAX) as a matrix and carbon nanotube (CNT) and armchair graphene as reinforcements as well as obtaining the flue gas diffusion rate using molecular dynamic (MD) analysis. Two different composition ratios of the flue gas with an equal ratio (1:1) and an actual post-combustion ratio were developed. The molecular dynamic simulation results obtained from LAMMPS and OVITO determined that graphene-based nanocomposites were better suited for the diffusion of the CO₂/N₂ and CO₂/N₂/O₂ flue gas compositions, and CNT-reinforced nanocomposite membranes performed better for the CO₂/O₂ flue gas blend.