ENABLING GASEOUS AMMONIA USE IN A COMPRESSION IGNITION RESEARCH ENGINE

With regulations imposing tighter restrictions on carbon emissions, it is crucial to explore the use of carbon-free fuels. Ammonia, NH₃, is increasingly being perceived as a dominant hydrogen carrier candidate fuel due to its efficient hydrogen atom arrangement, ease of storage, and for already having an extensive transportation network as the second most traded chemical in the world. There are, however, challenges that still need to be overcome to accommodate the use of gaseous ammonia in a traditional internal combustion engine. To this purpose, a thermodynamic analysis of the heat and mass transfer processes that occur during the withdrawal of the fuel from a compressed gas state is presented to aid in the design of research fueling systems. Moreover, other safety precautions must be taken, including the use of specialized personal protective equipment (PPE) due to the high toxicity of ammonia at relatively low ambient concentrations. The selection of appropriate equipment for the safe handling and use of ammonia in a laboratory setting is detailed, including ammonia-compatible hardware and instrumentation as well as necessary safety considerations inclusive of components such as the pressure regulator, flow meter, thermal generation device to prevent fuel system freezing, and consideration for a HORIBA MEXA 7100 style exhaust gas analyzer. The goal if this work is to provide an overview of the challenges regarding the usage of ammonia as a fuel, as well as guidance on the design process and equipment selection for research engine applications.