(3bg) Membranes for Hydrogen Separation and Adsorbents for Sulfur Removal: Application to IGCC Plants

Meeting the world’s rising energy demands in ways that are sustainable and environmentally compatible highlights the importance of developing advanced energy efficient separation and emission control technologies. While membrane separation is widely considered as one of the most promising alternatives to conventional energy-intensive industrial separations, high cost and difficulties in scale-up constrain their commercial application for high-temperature separations. To address these issues, we recently demonstrated a new concept to synthesize zeolite membranes for hydrogen separation using layered (2D) zeolites. The fabrication method consists of exfoliation of lamellar zeolites to the constituent nanosheets and forming well-packed monolayers on porous substrates. The pores that are perpendicular to the monolayers selectively transport hydrogen through the membrane. The proposed approach lays the foundation for the fabrication of viable membranes using a range of layered zeolites. My other work focused on sulfur removal using solid sorbents. In this project, I investigated the synthesis of mixed metal oxides with high H₂S adsorption capacity.

These two projects aim to synergistically improve the economy of integrated gasification combined cycle with carbon capture and sequestration (IGCC/CCS) technology. IGCC/CCS is of particular interest to coproduce electricity, hydrogen, fuel, and chemicals with near-zero emissions. However, the challenge associated with CCS technology is to improve the economy of the process to close the cost gap between IGCC/CCS and conventional coal-fired power plants. The Department of Energy (DOE) has reported that by integrating warm-gas cleanup technologies into IGCC plants, an improvement of 8% in thermal efficiency over conventional cold-gas cleanup methods is achievable. In this context, two aspects of IGCC/CSS plants will be discussed that both aim to eliminate the energy penalty associated with carbon capture and sulfur removal: hydrogen purification using membranes at high temperatures and desulfurization of fuel gas using solid sorbents.