SF₆ Recycling in Electric Power Equipment

Abstract

SF₆ has become a key insulation material in electric power transmission and distribution equipment. It allows to realize highly compact insulation and switching equipment which, due to its functional superiority, has replaced older insulation and switching technologies to a large extent. SF₆ has, however, recently been identified to be one of the strongest greenhouse gases. Unlike other substances with high environmental impact, SF₆ in electrical power equipment can not be substituted by an equivalent gas with better environmental performance. Although the SF₆ released hitherto does not contribute significantly to the greenhouse effect, concern remains about its long-term accumulation in the atmosphere as it has a long atmospheric lifetime. This makes it imperative to limit the application of SF₆ to closed systems and to reuse and recycle the gas systematically. in this contribution the basic concepts of handling and recycling the SF₆ in electric power equipment will be outlined based on a recently published committee document, the CIGRE SF₆ Recycling Guide. Major topics treated are the terminology used, the major SF₆ recycling fluxes, main features and performance characteristics of SF₆ reclaimers, quality control and categorization of used SF₆, basics features of handling SF₆ mixtures and environmentally correct final disposal of SF₆.