Global-warming potential

Gas chromatography

Thermal decomposition

Chemistry

Ecology

Chromatography

ReaxFF

Sulfur hexafluoride

Greenhouse gas

Organic chemistry

Biology

Hydrogen bond

Molecule

Analytical Chemistry (journal)

Radical

Decomposition

Industrial & Engineering Chemistry Research

The insulation characteristics and decomposition components of C4F7N/N2 gas mixture, a potential substitute for SF6, were first explored by breakdown experiments/gas chromatography–mass spectrometer. The structural properties of C4F7N molecule and the decomposition mechanism of C4F7N/N2 gas mixture were analyzed based on the density functional theory calculation and ReaxFF molecular dynamics simulation. We found that C4F7N/N2 mixture has great self-recovery performance. The decomposition of C4F7N in a discharge mainly produces CF4, C2F6, C3F8, CF3CN, C2F4, C3F6, and C2F5CN, among which the relative content of C2F6, CF4, and CF3CN is higher. ReaxFF-MD simulations show that CF3, CN, F, and C3F7 are the four main free radicals produced by C4F7N. The decomposition characteristics of N2 are better than that of C4F7N. The addition of N2 has a certain buffering effect to avoid the massive decomposition of C4F7N. The global warming potential value of a gas mixture containing 20% C4F7N decreased by 94.32% compared with SF6. Relevant results not only reveal the decomposition characteristics of C4F7N/N2 mixture in a discharge comprehensively, but also provide a reference for engineering application and emission of a C4F7N/N2 gas mixture.

Decomposition Properties of C4F7N/N2 Gas Mixture: An Environmentally Friendly Gas to Replace SF6