Sulfur hexafluoride (SF6) is an inert gas with high stability at room temperature and pressure. It is colorless, tasteless, odorless, non-toxic, and non-flammable. Due to its excellent insulation and arc-extinguishing properties, it has been successfully used in high-voltage electrical equipment since the 1960s, ushering in a major revolution in high-voltage electrical equipment. Entering the 21st century, the global power market has seen widespread adoption of fully enclosed switchgear, with voltage levels continuously rising, and the volume of sulfur hexafluoride gas charged has also increased significantly.
According to statistics, the domestic power industry’s annual demand for the gas is approximately 8,000 tons. Based on a 10% annual waste rate, this would result in emissions equivalent to 20 million tons of CO2 gas. With the rapid development of the power industry and improvements in technological equipment, demand for the gas is expected to rise rapidly.
Sulfur hexafluoride gas readily decomposes with oxygen and moisture under the action of an electric arc, producing a number of toxic, harmful, and corrosive substances, including sulfur tetrafluoride, hydrofluoric acid, and sulfur dioxide. These decomposition products pose varying degrees of risk to high-voltage equipment and personnel.
Sulfur hexafluoride (SF6) is also a significant greenhouse gas. Its single molecule has a greenhouse effect 23,900 times greater than that of CO2, making it one of the six greenhouse gases banned under the Kyoto Protocol.
Although my country has issued a series of standards and regulations regarding the production, management, and use of SF6, such as the “Guidelines for the Management and Testing of SF6 Gas in Electrical Equipment,” the “Guidelines for Seal Testing of SF6 Gas in High-Voltage Switchgear,” and the “Safety Protection Guidelines for Personnel Operating, Testing, and Maintenance of SF6 Electrical Equipment,” the indiscriminate release of SF6 during maintenance is common due to a lack of understanding of its greenhouse effects among maintenance personnel, a lack of on-site purification and treatment equipment, and chaotic management of SF6 use.
It is reported that while currently available recycling and recharging equipment boasts purification capabilities, it suffers from slow recovery speeds, significant gas loss, oil content, poor gas quality assurance, and storage in warehouses where it cannot be properly handled. At the same time, my country’s standards for recycled gas are much stricter than international ones. Therefore, recycled gas cannot be directly recycled into electrical equipment. It must undergo rigorous treatment and testing to meet standards before it can be reused.
It is understood that the purification and treatment center project, equipped with a miniaturized gas treatment system and testing room, can meet the development needs of my country’s power market and achieve true recycling of sulfur hexafluoride gas.
Post time: Aug-14-2025