Adsorbed $CO_2$ Dissociation Using Argon and Helium Nonthermal Plasma Flows

In recent years, global warming has become a worldwide problem. Carbon dioxide (CO2) is one of the primary substances causing global warming, and its emission should be reduced. A promising technology is the conversion of CO2 to carbon monoxide (CO) using plasma treatment, so that the CO itself or its conversion to methane can be used as fuel for combustion engines. In this article, a CO2 dissociation or reduction treatment system using an adsorbent and nonthermal plasma (NTP) flow is investigated. To improve the conversion efficiency, the conversion efficiency for Ar or He plasma is evaluated. In the physical adsorption process, ∼10% CO2 gas with a flow rate of 10 L/min is prepared, and then, it is introduced into the flow channel; CO2 is adsorbed by the adsorbent. After the adsorption process, the circulation flow channel is set, and then, the Ar or He NTP flow is generated with a blower. As a result, the adsorbed CO2 is desorbed with CO2 concentrations of 20% and 23% by the Ar NTP flow and the He NTP flow, respectively. The CO2 conversion efficiency reaches 21%, and the energy efficiencies reach 13% and 10% with plasma in the cases using the Ar and He NTP flows, respectively. The energy efficiency with regard to CO is better with the Ar plasma, but more atomic carbon can be generated using the He plasma.