Graphite production in two‐temperature non‐LTE plasmas of C4F7N and C5F10O mixed with CO2, N2, and O2 as eco‐friendly SF6 replacements: A numerical study

Many recent works have shown that C4F7N and C5F10O have a great potential to replace SF6 as a greenhouse gas. One of the biggest problems for their application is that condensed species (i.e., graphite) may be produced during gas discharges. However, all the previous works are performed under the assumption of local thermodynamic equilibrium (LTE). Therefore, this study investigates the departure of thermodynamic equilibrium and the corresponding effects on the graphite production in the plasmas of C4F7N, C5F10O, and their mixtures with CO2, N2, and O2, based on the two‐temperature (2T) non‐LTE plasma compositions calculated by the Gibbs free energy minimization. The results show that neglecting the nonequilibrium effect can lead to a very inaccurate description of graphite condensation in the above plasmas. The graphite production in non‐local thermodynamic equilibrium plasmas of eco‐friendly SF6 alternative gases is investigated numerically. It is found that neglecting the nonequilibrium effect can lead to a very inaccurate description of graphite condensation in the plasmas of C4F7N, C5F10O, and their mixtures.