In this presentation, we provide an overview of an ambitious project to store renewable energy through electrochemical synthesis of ammonia. The joint project between the Colorado School of Mines (Golden, CO) and FuelCell Energy, Inc. (Danbury, CT) is supported through the U.S. Department of Energy ARPA-E ‘REFUEL’ program. The research and development team seeks to harness the unique properties of proton-conducting ceramics to activate chemical and electrochemical reactions for efficient and cost-effective synthesis of ammonia.
The system concept is shown in Figure 1; renewable electricity is used to drive electrolysis of the H2O feedstock to form hydrogen. This electrochemically produced hydrogen then reacts with nitrogen over a proprietary catalyst (Starfire Energy, LLC, Golden, CO) to form ammonia. In addition to converting electricity into a commodity chemical, the system can be operated ‘in reverse,’ where ammonia fuel is electrochemically oxidized within the protonic-ceramic device to produce electricity.
The program is centered on scale up and advancement of proton-conducting ceramics, an exciting new class of materials that are now emerging from research laboratories to address societal challenges in electricity generation, energy storage, and fuels synthesis. We are exploring the promise of the technology through a number of parallel efforts. Through materials development, we seek to improve the electrochemical performance of the protonic-ceramic electrolyzer / fuel cell. We are developing pilot-scale manufacturing processes to build larger-area protonic-ceramic devices, and integrating these devices into higher-capacity, multi-cell stacks. This stack development brings questions regarding protonic-ceramic materials stability in the presence of metallic stack components, current collectors, and seals. We are developing electrochemical and catalytic models to advance our fundamental understanding of the ammonia-synthesis process. Further, we apply techno-economic models to explore the value proposition of electrochemical ammonia synthesis, and expose the key underlying cost drivers.
We will present an overview of this REFUEL program and recent results in this talk. The information, data, or work presented herein was funded in part by the Advanced Research Projects Agency-Energy (ARPA-E), U.S. Department of Energy, under Award Number DE-AR0000808. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.
Figure 1: Electrochemical ammonia-synthesis system.