Custom Modeling and Economic Analysis of Ion Transport Membranes for Oxygen Separation from Air

There is a growing demand for high purity oxygen as a replacement for air in oxy-combustion and gasification processes. The motivation to switch from air to pure oxygen lies in the pure oxygen’s ability to reduce emissions as well as to offer higher combustion efficiency. Traditionally enriched oxygen production is achieved using Cryogenic Air Separation and Pressure Swing Adsorption technologies. However, emerging membrane technologies such as Ion Transport Membranes (ITM) have shown to have the potential to be economically superior to the traditional gas separation technologies, offering higher purity of the desired product as well as lower energy consumption rates¹. Also, certain Perovskite materials such as La_0.6Sr_0.4Co_0.8Fe_0.2O_3-a (LSCF) have exhibited excellent mixed ionic-electronic conducting properties, making them ideal to be used in the development of membranes to separate oxygen from nitrogen in air².

This research contributes a new equation-oriented simulation of a Mixed Conduction Ceramic Hollow Fiber Membrane ITM air separation unit (ASU) for economic evaluation. The ITM air separation unit was built in Aspen Custom Modeler (ACM), with its necessary equipment sized using Aspen Plus. The ITM ASU was designed to be incorporated into a 519 MWe Integrated Gasification Combined Cycle (IGCC) power plant with carbon capture. Data from IGCC and ITM simulations were gathered for the economic evaluation and to create an equation that relates the cost of ITM air separation to the amount of desired oxygen product. Different oxygen production rates were assessed so that the ITM can be applied to more processes other than IGCC plants. Discussions on the comparison of the potential economic viability of ITM-based ASU to conventional cryogenic ASU units will be performed considering techno-economic data from recent literature³.

References

1. Armstrong, P. A. (2005). ITM Oxygen: The New Oxygen Supply for the New IGCC Market. 33.
2. Chen, Z. C., Atkinson, A. A., & Guiliani, F. G. (2014). Mechanical Properties of La0.6Sr0.4Co0.2Fe0.8O3 Fuel Cell Electrodes (Thesis). https://arxiv.org/ftp/arxiv/papers/1502/1502.02149.pdf
3. James, R., Kearins, D., Turner, M., Woods, M., Kuehn, N.; Zoelle, A. (2019). Cost and Performance Baseline for Fossil Energy Plants Volume 1: Bituminous Coal and Natural Gas to Electricity. doi:10.2172/1569246