Greenhouse gases (GHG) are gases that trap heat in the atmosphere. There are gases that are found naturally in the atmosphere, others that are enhanced through human intervention, and a third group that are those synthesized by man and that only exist due to an industrial process.
Within this third group, Fluorinated gases are potent, synthetic greenhouse gases that are emitted in various industrial processes.. Fluorinated gases are used, among other applications, as refrigerants, as fire extinguishing agents, solvents and for the manufacture of insulating foams. Among them we can find Hydrofluorocarbons (HFC), Perfluorocarbons (PFC) and Sulfur hexafluoride (SF6).
These gases are usually emitted in small quantities and are known as gases with high Global Warming Potential (GWP), because they can heat the air much more than the same amount of CO2.
The three GHG incidence factors
The effect of each gas on global warming depends on these three factors:
Concentration: is the abundance of a given gas in the air. GHG concentrations are usually measured in parts per millionapproximately equivalent to that of a drop of water diluted in 50 liters of liquid.
Permanence: GHGs can remain in the atmosphere for different periods, from a few to a few thousand years. And because all of these gases remain in the atmosphere long enough to mix well, their concentration in the atmosphere is approximately the same around the world, regardless of the source of the emissions.
Warming potential: a measure of how destructive a GHG is.. Today, refrigerants are typically thousands of times more polluting than carbon dioxide (CO2). Each GHG has its Global Warming Potential (GWP). Gases with a higher GWP absorb more energy per kilogram than those with a lower GWP and therefore contribute more to Earth’s warming.
The powerful and harmful SF6
Among the synthetic fluorinated compounds, sulfur hexafluoride or SF6, stands out for being the most powerful of all GHGs.
SF6 is an inert, non-toxic and colorless gas that is widely used in the electrical industry. Low cost, this GHG is used as a high-efficiency insulating material in medium and high voltage electrical installations.such as power plants and wind turbines to prevent short circuits and fires.
But the biggest problem with this gas is that It has a greater global warming potential than any other known substance. According to the National Atmospheric Emissions Inventory of the United Kingdom, SF6 has a GWP of 22,800.
This indicates that one ton of this GHG is equivalent to 22,800 tons of CO2an amount similar to that 17,500 people would emit during a round-trip economy class flight from London to New York. On the other hand, SF6 is capable of remaining within the Earth’s atmosphere for more than 1,000 years, which implies a catastrophic risk for our planet.
The SF6 paradox
SF6 emissions in Europe and most of the planet have maintained their levels, but those in China have almost doubled in the last 10 years. This is because the ways in which electricity is generated are changing: coal plants are being replaced by other options that combine wind, solar and gas energy to varying degrees.
These new systems require many more connections to the electrical grid, with the consequent use of switches and other mechanisms to prevent accidents. AND the vast majority of these safety devices use SF6 as an insulator to avoid them.
The number of wind farms and solar farms requiring more SF6 safety devices is growing at a rapid pacesince this gas is an economical, reliable option that requires little maintenance.
Since SF6 is a synthetic gas, it cannot be absorbed naturally like CO2. It must then be captured and deliberately destroyed to minimize its environmental impact. But since there are no restrictions on its use, except for voluntary commitments, it is used indiscriminately, being SF6 concentrations in the atmosphere that are 10 times higher than those officially declared by the countries.
The paradox then is that, to combat climate change through renewable energy, we use the most powerful greenhouse gas ever created, in an unprecedented climate feedback loop.
Although new regulations on fluorinated gases came into force last month that toughen the progressive elimination of these powerful gases by 2050 in the European Union, the truth is that In much of the planet, SF6 will continue to be used, warming the atmosphere for centuries..
