Membrane Transport for Gas Separation

Gas separations through organic membranes have been investigated from last several years and presently it has been accepted for commercial applications. This chapter will focus on membrane based gas separation mechanism as well as its application. This chapter will cover ‘‘diffusivity controlled’’ and ‘‘solubility controlled’’ mechanism and choice of suitable polymers for different gas phase applications like acidic gas, C3+ hydrocarbon, nitrogen, water vapor and helium. Diffusivity controlled mechanism performs on free volume elements of the glassy polymers via hindrance of chain packing by functional groups and restricted by the permselectivity. Other mechanism performs on the basis of molecular structure with affinity towards the target molecule and follows enhanced solution-diffusion rout. Commercially available organic membrane materials for Carbon dioxide (CO2) removal are discussed along with process design. Membranes based separation process for heavy hydrocarbon recovery, nitrogen separation, helium separation and dehydration are less developed. This article will help us to focus on the future direction of those applications based on membrane technology. Keywords: Membrane, C3+ hydrocarbon, Diffusivity controlled, Solubility controlled, Selectivity, Permeability. *Corresponding author: E-mail address: c.bhatta@gmail.com (Chiranjib Bhattacharjee), Tel.: +91-9836402118.