Multilayer Polymeric Composite Membrane for Gas Separation

Gas separation is the process of separating primary gaseous components from the composition of air. The separated primary gaseous components are essential for many industrial purposes such as chemical, medical, aeronautical, food processing industries. Oxygen enriched air plays a crucial role in the fuel combustion process and medical applications. Membrane technology emerges in the field of gas separation due to its inherent multidirectional characteristics. The multilayer composite polymeric membrane has been developed using electrospun web, nonwoven substrate and casting polymer solution to improve the permeability and selectivity of oxygen gas molecule from the gas mixture. This membrane also consists of polyethylene glycol (PEG) and SiO₂ nanoparticles which are used to improve the permeability and selectivity of oxygen molecules. Box- Behnken design has been wielded for the membrane construction by three independent variables such as volume of electrospinning solution (mL), Casting Solution (mL) and PEG concentration (%). Oxygen separation is carried out using the gas separation unit and it is constructed based on the principle of air separation. To analyze the performance of the developed membrane, the purity of oxygen from the composite membrane is estimated by a GC-MS. Mass per unit area and thickness of all membrane samples has been tested. From the results, the electrospun web thickness and casting solution concentration directly influence the oxygen purity and air separation rate. SiO₂ nanoparticles are added to the casting solution and the electrospun web. The presence of SiO₂ in the top and bottom layer of the membrane is used to attract the O₂ molecules. Maximum oxygen purity was obtained from the membrane which has an electrospun web with 6mL and 30% casting solution with 2% PEG. From this flat sheet composite membrane, the purity range of oxygen is 42.2% with moderate permeability flux.