(585p) Adaptive Test Bed for Anhydrous Ammonia-Based Energy Systems

Proof-of-concept requires bench-top testing of material coupons and working fluids. Engineering development, including hardware design and fabrication, system integration, and scale-up testing can be even more difficult. The authors have designed a platform―or test bed―for developmental testing of subsystems and components of anhydrous ammonia-based energy systems.

We refer to our concept as a composite ammonia flow battery (CAFB). It consists of the following subsystems: wind turbines, power conditioning, ammonia synthesis unit, ammonia storage, system data acquisition and control (SCADA), and output. If the end product is electricity, the output subsystem can be either a fuel cell or a motor-generator; no additional subsystem is required if the system output is to be liquid fuel or fertilizer. Numerous options exist for the synthesizer―for example Haber-Bosch, molten salt, polymer-electrolyte membrane, solid oxide, non-thermal plasma reactor, or others. For long-term testing an air separation unit and electrolyzer could be incorporated in the synthesis subsystem; but short-term tests could operate on simulated external power and bottled gases. The storage subsystem could be refrigerated; but because NH₃ is readily stored with no losses at ambient temperature and 8-10 atm, the latter is more attractive for energy systems. The output subsystem could include a splitter to reduce NH₃ to H₂ and N₂ and the H₂ fed to a hydrogen fuel cell. However, recent progress toward developing a direct ammonia fuel cell (DAFC) indicates that the splitter may become unnecessary.

We have developed an algorithm for predicting full or partial system efficiency from measured performance of the subsystems and components; and we are configuring the whole system so that it can be packaged in a CONEX container for transportation to a field test site (e.g., a wind farm).