Energy-Distribution-Based Parameter Screening of Corona Discharge Reactors: Achieving Efficient Trimethylamine Removal With Minimal Ozone per Removal Unit

Volatile organic compounds (VOCs) tend to accumulate in the confined, humid environment of household refrigerators, posing health risks. Trimethylamine (TMA), an odorant generated from decaying meat, is designated as the indicator gas for deodorization performance by the Chinese national standard GB 21551.4-2010. Nonthermal corona discharge is effective in decomposing TMA but inevitably produces ozone, a byproduct whose emission varies with reactor configuration and operating conditions. To address this, a physics-informed, reduced-order descriptor based on the mean electron energy distribution in the discharge region is proposed to guide reactor design. A 2-D plasma calculation is used to obtain the mean electron energy distribution. Two energy thresholds are introduced to define an effective energy region$S_{1}$(where the mean electron energy exceeds the threshold relevant to TMA bond scission) and an excess energy region$S_{2}$(where the mean electron energy exceeds the threshold associated with ozone propensity). Their area ratio$\eta = S_{2}$/$S_{1}$is introduced as an indicator for ozone propensity. Numerical calculations are conducted for 120 configurations in wire-plate and needle-ring reactors to obtain$\eta $values. The selected configurations with stable corona discharge were tested for TMA degradation rates ($V_{1}$) and ozone generation rates ($V_{2}$), and a performance factor$\alpha = V_{2}$/$V_{1}$is defined. A strong correlation (adjusted$R^{2} =0.9682$) between$\eta $and$\alpha $supports the descriptor’s validity. Considering both calculation and experimental results, the wire-plate reactor outperforms the needle-ring reactor. The wire-plate reactor with 0.1-mm wire diameter, 10-mm gap, and 9-kV voltage achieves the lowest$\alpha $and$\eta $, identifying it as the optimal configuration. The proposed framework enables rapid, low-cost optimization of corona-discharge deodorization systems for confined spaces, such as household refrigerators.