Adsorption properties of environmentally friendly insulating medium C4F7N and its common decomposition products in NaA, NaZSM‐5, and NaX molecular sieves

Abstract

Abstract Selecting suitable materials to adsorb the C4F7N mixtures decomposition products could not only keep the stable operation of the environmentally friendly insulating gas switch cabinet, but also ensure the safety of operation and maintenance personnel. It is necessary to study the interaction of three types of molecular sieves with the C4F7N mixture and its decomposition products, which could provide a theoretical basis for the selection of adsorbents in the C4F7N gas switch cabinet. In this research, the molecular dynamics simulation was used to study the C4F7N‐CO2 mixture and its ten kinds of decomposition products CO, CF4, C2F6, C3F6, C3F8, CF3H, CF3CN, C2F5CN, C2N2, and COF2 in three molecular sieves adsorption process (NaA, NaZSM‐5, and NaX). The gas concentration distribution curve and interaction energy parameters were obtained by simulation. The interaction energies of C3F8 in NaA, C4F7N in NaZSM‐5, and C3F6 in NaX molecular sieve are the largest, which are −368.35 kJ/mol, −174.93 kJ/mol, and −340.09 kJ/mol respectively. Then, the theoretical results were verified by the fluorocarbon gases adsorption experiment. The adsorption performance of three molecular sieves for all gases was obtained by combining the experimental results and dynamics parameters. The adsorption rate of the NaA molecular sieve for fluorocarbon gas is less than 35%, and its adsorption performance for all gases is weak. NaZSM‐5 and NaX molecular sieves show excellent adsorption performance for C3F6 and C3F8, and the adsorption rates are over 70%. NaZSM‐5 molecular sieve shows good adsorption capacity for CF3CN, C2F6, C2N2, C3F6, C3F8, C4F7N, and C2F5CN. NaX molecular sieve shows good adsorption capacity for C3F6, C3F8, C4F7N, and C2F5CN. Both of them have the potential to be used as adsorbents in environmental protection insulated gas switch cabinet.