(396d) Novel Double Salt Membranes for Warm Syngas CO2/H2 Separation

Membrane-based technology has shown advantages over other systems for warm syngas CO₂/H₂ separation due to its low capital investment, high process flexibility, energy efficiency, and ease of operation. When a CO₂-selective membrane is used, its benefits also include: (1) the generation of high purity H₂ on the high-pressure feed side, thus eliminating the recompression of H₂ for downstream use, and (2) lower membrane area can be used as compared to a H₂-selective membrane, thus saving capital cost. However, there has thus far been few membrane developed for practical use for CO₂/H₂ separation in the temperature range of 300-400C due to the limitations of existing membrane materials. MgO-based double salt crystals (e.g. Na₂MgCO₃), promoted by NaNO₃,  show high CO₂ adsorption capacity and fast adsorption-desorption cycling properties at the above-mentioned temperature range by pressure swing and can potentially be developed as a CO₂-selective membrane. In this talk, we will present our recent progress on the development of double salt membranes for warm syngas CO₂/H₂ separation. This presentation will provide systematic discussion on impacts of both membrane composition and membrane separation conditions, such as temperature, feed pressure, and water steam content, on the membrane separation performances.  The membrane separation mechanism will be discussed as well.