[20p-A401-1~10] The Utilization of Plasma Science for Realizing a Circular-Economy

2:05 PM - 2:35 PM JST(5:05 AM - 5:35 AM UTC)

[20p-A401-3] Plasma Technology for Sustainable Nitrogen Recycling

〇Hyun-Ha Kim¹, Ayman AA¹ (1.AIST)

Keywords:

spark plasma,nitrogen fixation

Plasma nitrogen fixation is one of the promising processes for electricity-driven valuable compounds which is also referred to as power-to-X (X = H₂, NH₃, NOx, alcohols, etc) processes. Haber-Bosch process has been the key technology of nitrogen fixation over 100 years, which is also representative chemical processing based on high temperature and high pressure. In this work, we aimed to present a deep understanding of NO_x formation by nonthermal plasma and to unveil the most crucial parameters to reduce energy cost. To this end, NOx formation in DBD and spark discharge reactors was investigated under various operating conditions. Rotational and vibrational temperatures were estimated using optical emission spectroscopy and theoretical fitting. The spark discharge is more efficient due to its ability to generate more vibrational excitation, which is pivotal to reduce the energy cost. Moreover, the proper design of the plasma reactor to provide larger plasma-air processing is important. Meanwhile, the gas flow rate and temperature have an influence on the selectivity and no effect on reducing the energy cost, as the energy cost follows the energy density.