Performance evaluation of nonthermal plasma carbon dioxide reduction to fuel with dielectric barrier discharge

Abstract

Carbon dioxide captured from the atmosphere can be reduced to carbon monoxide, which can then be used as a fuel or material for conversion to organic compounds and for gas synthesis. However, currently, this energy source has low efficiency and its use is impractical because of the relatively low atmospheric CO₂ concentration, which disperses input energy. Therefore, it is important to concentrate atmospheric CO₂ during pretreatment. In this study, a plasma reactor is partially filled with an adsorbent and atmospheric air is allowed to flow into the reactor after the removal of water vapor using a condenser and silica gel to adsorb atmospheric CO₂ (i.e., the adsorption process). During desorption and reduction, nonthermal plasma flow is generated via dielectric barrier discharge, while nitrogen is flowed into the reactor to reduce atmospheric CO₂ (i.e., the desorption–reduction process). As a result, the CO₂ concentration reaches 545 ppm in 230 min during the adsorption process and 5519 ppm in 12 min during the desorption–reduction process. The CO concentration increases to 60 ppm in 12 min during the desorption–reduction process. The conversion and energy efficiencies are 1.1 % and 1.9 × 10⁻² %, respectively. The introduction of the adsorption process not only increases the concentrates CO₂ but also decreases the concentration of water vapor in the reactor and generates more CO, thereby increasing the energy efficiency. Therefore, the introduction of an adsorption process is extremely important for improving the concentration and reduction of CO₂.