In the past three decades, the amount of CO2 (greenhouse gas) in the Earth's atmosphere has increased by 18% and is believed to be a significant factor in global climate change [1]. It is therefore prudent to 1) reduce CO2 emissions to the atmosphere from power generation and 2) sequester the currently high levels of CO2 in a secure storage environment. Figure 1 shows a schematic of a concept capable of meeting both goals. A key part of this process is the separation of CO2 from the reformed fuel (pre-combustion), where it is advantageous to maintain a high temperature and pressure of the reformed fuel, minimizing inefficiencies from heat loss and compression of CO2 exhaust for sequestration, respectively [2]. These constraints require a membrane capable of intermediate temperature operation at high pressure, with tolerance to the reducing environment. In this collaborative work with Assoc. Professor Fujikawa in the CO2 separation and concentration division, we are investigating thin oxide proton conducting membranes deposited on porous supports using spin-on techniques. The thin film morphology reduces transport barriers to hydrogen permeation. New materials are being investigated using advanced characterization techniques such as impedance spectroscopy and permeation measurements aided by mass spectrometry.
1. http://www.esrl.noaa.gov/gmd/ccgg/trends/
2. J. Ciferno et al., "DOE/NETL Carbon dioxide capture and storage RD and D Roadmap," National Energy Technology Laboratory Report, Dec. (2010).
