Experimental Study of C4F7N and its Decomposed Products Adsorption on Gamma-Aluminum Oxide

摘要

Replacing SF6 in gas insulated high-voltage equipment is now a hot topic, and Heptafluoroisobutyronitrile (C3F7CN) has received extensive attention because of its excellent insulation performance and low GWP value. Whether activated alumina (γ-AI2O3), a common adsorbent in traditional SF6 based equipment, can be applied in C3F7CN based equipment, need to be discussed. In this work, the discharge experiment of C4F7N/N2 was carried out, and the result shows that the decomposition products mainly contained several fluorocarbon and fluorocarbon nitrogen, such as CF3CN, C2F5CN, CF4, C2F6, C3F8, C2F4, C3F6. Then, gas samples were collected after different times of discharge, and the gas adsorption experiments of these compounds by γ-AI2O3 was analyzed and calibrated by gas chromatography. The results show that the C3F7CN and its decomposed products which contain C=N exhibits obvious adsorption behavior, and γ-AI2O3 can be used for adsorbent toward compounds containing cyano-group in environmental insulation equipment using C3F7CN as medium.