Oxygen Selective Metal Organic Framework Adsorbents for High Efficiency Air Separation

While cryogenic ASU is the technology of choice to supply oxygen to large plants, they are very expensive and includes complex hardware that prevent to cost-effective scale down and use in small installations. At small scale, pressure swing adsorption (PSA) is widely used. PSA is based on the selective reversible adsorption of nitrogen (but not oxygen) onto molecular sieve sorbents. The conventional PSA process delivers an expensive product mainly due to the inefficiencies involved in the adsorption of the major component (nitrogen) from a high pressure air and its subsequent discharge at ambient pressure (most of the work input provided during compression is lost). Sandia National Laboratory researchers have recently developed a novel method to synthesize open pored metal organic frameworks (MOFs) which exhibit high selectivity for oxygen. Due to this highly selective to oxygen the separation process could be potentially significantly more energy efficient than conventional PSA process. TDA Research Inc. (TDA) proposes to further develop these new materials into manufacturable, highly effective adsorbents. We will also develop a highly efficient separation process based on their use supported by detailed engineering design and process simulations. In Phase I, we will synthesize the new MOFs at large-scale using high throughput commercial equipment. We will use low energy densification techniques to make pellets or granules while preserving the desired adsorptive properties. We will demonstrate the stable operation of the new material through many cycles under representative conditions. We will design and optimize a cycle sequence that will achieve both high product (oxygen) yield and purity. We will complete a techno-economic analysis to assess the economic merits of the new technology. Oxygen is a strategically important chemical, with a $3.8 billion market value in the U.S. It supports various industrial processes and enters into oxidative combination with many materials. The new technology has the potential to reduce the energy input required for the process by more than 2X, providing a low cost oxygen product.