In-Cylinder Ammonia Production Using Internal Combustion Engine Enabled by a Low Temperature Plasma

Around 353 billion cubic feet of gases were flared in the U.S. in 2016. At 2 $/MCF, the value of these flared gases is equivalent to $706 Million of lost income. Flaring these gases resulted in emitting 26 Million Metric tons of CO2. Plasma Energy Innovation LLC., an MIT spinoff, will develop a novel, ultra-compact and low cost gas to liquids mini-plant using modified automotive internal combustion engines as small scale chemical reactors and compressors. Using a mass produced product- internal combustion engines in place of custom made chemical process equipment enables significant cost reductions. The plant, located near the wellhead, will process natural gas that would otherwise be flared into ammonia, a high value chemical that can be transported to market. Two process steps, performed in two different engines, are to be employed in the plant. The goal of this program is to investigate the second engine, where the produced gases are compressed and converted into ammonia. Ammonia synthesis is achieved on a high surface area, open-cell alumina foam impregnated with a catalyst placed inside the piston bowl. The synthesis process is assisted by a non-thermal plasma generated in cylinder when the piston is near top-dead center. Non-thermal plasma processes at atmospheric pressures have been explored as an alternative to the conventional Haber Bosch ammonia synthesis. From a materials standpoint, the plasma has the potential of healing catalyst defects and activating the catalyst. Plasma treated catalysts have also shown greater tolerance against poisoning. This is especially important in this application where the reactant stream will contain not only N2 and H2, but also CO2 and possibly also CO and H2O which are temporary poisons for most catalysts. During Phase I, Plasma Energy Innovation will 1) demonstrate a proof of concept engine that can synthesize ammonia from nitrogen and hydrogen using plasma catalysis at high pressure and 2) perform a techno-economics analysis of a system integrating the engine reactor into a compact gas to chemicals plant to be placed near the wellhead.