SF6 gas – the seemingly perfect insulation gas
Unfortunately, in many cases there still are no alternatives for SF6 gas
SF6 gas seemed to be the perfect protection- an insulation gas for a long time. It is odorless, non-toxic, not inflammable, chemically very stable and since it is an inert gas, it displaces oxygen, which reduces the fire hazard. The disadvantage – SF6 gas has 24.300 times the greenhouse effect of CO2, which makes it the strongest known greenhouse gas. There is almost no SF6 gas present in nature and is produced by humans for technical use. Because it is so chemically stable, the energy needed to destroy the chemical bond is extremely high. If left intact, SF6 gas stays in the atmosphere for about 3.200 years.
The seemingly perfect SF6 gas has been used in tennis balls, insulation windows, Nike Air shoes and other everyday products in the past. Only when the effect of certain substances on our climate came into focus, the use of SF6 gas was prohibited for these kinds of products and was strongly limited to certain sectors. While SF6 gas was used for a wide variety of products in the past, a huge amount has gone into our atmosphere unhindered.
Through the legal requirements regarding SF6 gas, the handling is strongly regulated and only people with expert training are allowed to do so in Europe. Since the climate damaging effects of SF6 gas are so strong, it is essential to ensure that no gas escapes into the atmosphere when handling.
This is especially relevant in three areas:
Production of new gas
The production of new SF6 gas has a big negative impact on the environment. The production plants emit a significant amount of SF6 gas to the atmosphere due to their technical standards. There is also a big amount of emissions produced through the transport routes from the main production locations in South Korea, Russia and China to Europe.
Maintenance and handling of SF6 plants
It is technically impossible to evacuate or fill gas to and from SF6 plants without releasing at least a small amount of emissions. There are always minimal amounts of residual gas in pipes, valves or bottles, that can’t be caught fully. The emissions can be kept to a minimum through competent and cautious handling and proper technology within the plants. New concepts for plants allow for longer maintenance cycles, which reduce the need to remove SF6 gas from closed systems and refill them.
Disposal of SF6 gas after use
SF6 gas is a synthetic gas, that does not occur in nature. The technical advantage this chemical bond, consisting of one sulphur- and six fluoride atoms, brings turns out to be a big disadvantage when trying to dispose of it. Only a chemically and thermally very stable connection like SF6 is a good insolation medium. Up until now it is common to burn used and polluted SF6 gas with extremely high temperatures to break it down and make it lose it’s harmful properties. By treating polluted SF6 gas and reusing it, the wasteful use of high amounts of energy can be avoided. In the method we use, the small amount of pollution and decomposition products formed by the use of SF6 gas are removed and the gas can be reused as new gas would. This is recycling in the most literal sense of the word, since the substance is reused directly. This way there is no need for the production of new gas and huge amounts of energy are saved.
Of course, the ideal solution for us humans as well as our climate would be the invention of an alternative to SF6 gas so there would be no need to use it anymore – and there are many people working on finding a suitable alternative, but unfortunately at the moment, there is no proper alternative for the use of SF6 gas available in many sectors for various reasons. The problem is not limited to the lack of alternatives for SF6 gas in the worldwide electricity grids – the need for electricity among the population is increasing at an unprecedented rate through the intensive use of data, increasing electrification of vehicles, new data centers and higher performance in computers. This means our electricity grids need new SF6 gas plants. This makes it even more important to evacuate used gas emission free from old plants, treat it and reuse it in new plants without the need to produce new SF6 gas. This is the only way to keep emissions as low as possible and minimize the effect on our environment when handling SF6 gas.
