Sulfur hexafluoride is a colorless, odorless, non-toxic gas with excellent insulating properties. Due to its high insulation strength, excellent arc extinguishing performance, cooling characteristics, non-flammability, and thermal stability, sulfur hexafluoride equipment is widely used in power transmission systems.

  However, sulfur hexafluoride gas is a greenhouse gas and has the potential to contribute to global warming.

  Sulfur hexafluoride electrical equipment has been widely used in substations since 1993. After 10 years of use, this equipment undergoes major overhauls. Traditionally, the gas is directly released into the atmosphere, causing environmental pollution.

  As an industrial gas, sulfur hexafluoride is an excellent insulating gas for electrical equipment. However, as one of the six greenhouse gases, it is calculated that sulfur hexafluoride gas is 23,900 times more damaging to the ozone layer than carbon dioxide. Moreover, sulfur hexafluoride gas can persist in the atmosphere for up to 3,400 years, causing long-term damage to the ozone layer.

  With the promotion of new technologies and the application of new equipment and materials, sulfur hexafluoride equipment has been widely used in power systems due to its safety, reliability, ease of maintenance, and long service life. It plays an important role in the safe, economical, and stable operation of power systems.

  Frontline operators and maintenance personnel have gained a deeper understanding of the characteristics, uses, hazards of sulfur hexafluoride gas, and how to take preventive measures during daily contact. They have developed new ideas for the recovery of sulfur hexafluoride gas and can correctly use protective clothing, gas masks, and other protective equipment. They are also able to implement relevant safety measures more standardized during operations and maintenance.

  Currently, the world emits approximately 21 billion tons of carbon dioxide gas annually, while the annual emission of sulfur hexafluoride gas into the atmosphere is equivalent to 1.25 billion tons of carbon dioxide gas.

  For a considerable period in the future, it is necessary to reduce the use of sulfur hexafluoride gas and explore safer alternative gases.

  Therefore, reducing sulfur hexafluoride gas emissions is one of the important measures for building a green power grid, promoting clean development of the power grid, and controlling global climate warming. Currently, technologies using nitrogen or nitrogen-oxygen mixtures or dry air as the main insulating medium to replace sulfur hexafluoride gas insulation materials have emerged. However, these are mostly applied research or improvements of existing technologies, and their environmental benefits or theoretical social efficiency improvements are not clear. At this stage, they are more of a demonstration and an attempt at new technological approaches.