Investigation of Synthesis and Dielectric Properties of c-C4F8O With Its CO2/N2 Mixtures as SF6 Alternatives in Gas-Insulated Applications

The usage and emission of SF 6 has been regulated because of high Global Warming Potential (GWP) and long atmospheric lifetime as an insulator in high voltage power transmission equipment. This paper proposes c-C 4 F 8 O and its mixtures as a substitute for SF 6 with low GWP and superior insulation performance. c-C 4 F 8 O is synthesized by 1,4-diiodoperfluorobutane and fuming sulfuric acid with the yield of 55.7% under optimal conditions. The GWP of c-C 4 F 8 O is about one-third that of SF 6 and its dielectric strength is about 1.2–1.4 times that of SF 6 . CO 2 and N 2 are mixed with c-C 4 F 8 O to lower liquefaction temperature and GWP. The investigation of breakdown voltage and self-recoverability of gas mixtures has shown that the insulation performance and stability of c-C 4 F 8 O-N 2 is better than c-C 4 F 8 O-CO 2 mixtures. The decomposition process of c-C 4 F 8 O might produce some nonflammable or inexplosive by-products, such as C 2 F 4 , c-C 2 F 4 O, c-C 3 F 6 and CF 2 O simulated by Gaussian 09. The results indicate that c-C 4 F 8 O and N 2 mixtures have potential to replace SF 6 in electrical equipment.