(659c) Surface-Modified Nanocomposite Membranes for Separation of CO2 From Natural Gas

Removal of CO2 from natural gas is an important industrial process. Among the various techniques that can be applied for this process, membrane technology is an economically attractive and environmentally friendly option. Membrane processes are generally easy to operate and are portable making them suitable for offshore and remote-location applications. Polymeric membranes have typically been investigated for this application; however, one major disadvantage associated with pure polymeric membranes is that they are susceptible to plasticization effects which significantly reduces selectivity at higher feed pressures. An alternative to polymeric membranes is the formation of hybrid organic-inorganic membranes by surface-derivitization of ceramic membranes.

In this study commercially available 5 nm Membralox and 5nm Anodisc membranes were modified by attaching ethoxy and methoxy aminopropyl silanes to the porous surfaces of the inorganic membranes. Single gas and mixed gas permeation experiments were conducted to evaluate the performance of the modified membranes. Our results showed a significant increase in CO2/CH4 selectivity as compared to untreated membranes. This study provides useful answers in designing nanocomposite membranes by surface modification that provide both high selectivity and high permeability.