Ammonia Generation Using Electric Discharge Plasma Generated in Steam
K. Yamasaki1, H. Hayashi1, M. Kuzumoto2, H. Kurita1, K. Takashima1, and A. Mizuno1
1Department of Environmental and Life Sciences, Toyohashi University of Technology, Japan
2Power Electronics Technology Laboratory, Advanced Technology R&D Center, Mitsubishi Electric Corporation, Japan
Abstract- Steam, nitrogen, and atmospheric pressure discharge plasma were combined to generate ammonia for on-board NOX (nitrogen oxides) reduction via SCR. Steam and nitrogen were treated under the discharge plasma generated by a packed bed reactor. We examined the optimum condition for the ammonia generation. Furthermore, five catalysts (Al2O3, BaTiO3, TiO2, CeO2, Al2O3) and CO (carbon monoxide) addition were examined to improve the energy efficiency for the ammonia generation. As a result, ammonia was detected in the treated gas when TiO2, CeO2 and Ru-Al2O3 were used. And NH4+ was detected in the cooled steam for all catalysts. Ru-Al2O3 showed the highest ammonia production, the energy efficiency. Furthermore, CO addition improved the energy efficiency in ammonia production when TiO2, CeO2, and Ru-Al2O3 were used. CO addition was also effective in reducing NOX generation when TiO2, CeO2, and Ru-Al2O3 were used. Ru-Al2O3 with CO addition showed the highest energy efficiency and the lowest NOX generation. From these result, it was suggested Ru-Al2O3 is best for ammonia generation and CO addition is also effective to improve the energy efficiency, and to reduce the NOX generation.
Keywords- Plasma, steam, ammonia, catalyst