Abstract

As the world is shifting toward renewable energy, natural gas consumption has increased since it emits less carbon compared to coal and oil. To meet this increasing demand, natural gas industries are largely investing in upgrading gas processing infrastructure. Gas processing is required to eliminate impurities, primarily by using absorption, adsorption, and cryogenic processes. Conventionally, the natural gas is dehydrated by the glycol absorption unit, which has complex process and maintenance issues; hence, alternative technology needs to be developed.

Membrane technology may be a viable option for sour gas treatment, hydrocarbon dewpointing, and dehydration in natural gas treatment. The membrane process has a significant potential for gas dehydration as it is small, durable, energy-saving, and commercially marketable. In the case of natural gas dehydration, water vapor is separated from a mixture of methane, carbon dioxide, and heavy hydrocarbons. Although most polymeric membranes have a very high selectivity of water vapor over methane, recent research has proved that this specific membrane application is limited by methane loss due to mass transfer limitations. Therefore, intensive study for lab-scale membranes under a harsh processing environment is required to develop membrane materials for this application.

This work aims to develop a high-performance polymeric membrane for natural gas dehydration by enhancing gas separation properties of mechanically and thermally stable polymers blended with highly hydrophilic polymers. Dense films were fabricated with polymer blends and characterized by several techniques to understand the blending behaviors and the intrinsic gas separation properties. To further improve the performance for natural gas dehydration, thin-film composite membranes were fabricated and characterized with mixed gases, and their stability was evaluated under harsh stream conditions.