Greenhouse gas HFC-23: Abatement of emissions is achievable
Novel measuring method for gas emissions Greenhouse gas HFC-23: Abatement of emissions is achievable Researchers from Empa, the University of Bristol and the Netherlands Organization for Applied Scientific Research (TNO) have investigated
Hydrofluorocarbons (HFCs) are potent greenhouse gases (GHGs). The most potent of these compounds is trifluoromethane, also known as HFC-23. One kilogram of HFC-23 in the atmosphere contributes as much to the greenhouse effect as 12,000 kilograms of CO₂. It takes around 200 years for the gas to break down in the atmosphere. For this reason, more than 150 countries have committed to significantly reducing their emissions of HFC-23 as part of the Kigali Amendment to the Montreal Protocol.
The main source of HFC-23 is the industrial production of certain coolants and of polytetrafluoroethylene (PTFE), better known as Teflon. HFC-23 is a by-product of the synthesis of a precursor to Teflon. Since 2020, all Teflon manufacturers are obligated to destroy the climate-damaging gas. According to the reports of the individual countries, this is happening: On paper, global emissions of HFC-23 for the year 2020 were only 2,000 tons. The actual global emissions, which have been determined in numerous studies, show a different picture: In 2020 alone, around 16,000 tons of the GHG were released into the atmosphere.
Accurate measurements thanks to tracer gas
Why this discrepancy? To answer this question, researchers from Empa, the University of Bristol and the Netherlands Organization for Applied Scientific Research (TNO) took a close look at HFC-23 emissions from a Teflon factory in the Netherlands. They have just published their latest findings in the journal Nature.
In order to record the factory's emissions as comprehensively and accurately as possible, the researchers used a novel method. They released a tracer gas right next to the factory: a non-toxic gas that does not occur in the atmosphere and decomposes within just a few weeks. At a distance of around 25 kilometers, they measured the concentrations of HFC-23 and other by-products of Teflon manufacture – and also the concentration of the tracer. "Since we knew exactly how much tracer we had released and how much of it arrived at the measuring point, we were able to calculate the emissions of HFC-23 and other gases," says first author Dominique Rust, who worked on the project as part of her doctorate at Empa.
The factory utilizes abatement measures to curb its HFC-23 emissions; the gas is burned off before it can escape. But the new study shows: "The emissions we measured were higher than the ones the factory reported", explains Empa researcher Martin Vollmer. "However, the amount emitted is still low, showing that the abatement measures work well." Co-author Kieran Stanley from the University of Bristol agrees: "These results are really encouraging. They show that abatement measures for plants producing fluoropolymers like Teflon can significantly reduce emissions of this highly potent GHG." And Empa researcher Stefan Reimann adds: "If all factories had emissions similar to the one we measured, we could prevent global HFC-23 emissions corresponding to almost 20% of CO₂ emissions from global air traffic."
Verification and compliance
So if the abatement measures are effective, how can the high readings in the atmosphere be explained? "We must assume that the measures reported by the countries do not correspond to reality everywhere," says Martin Vollmer. The authors of the study call on countries to have their Teflon factories independently audited. "Such independent verification of GHG emissions from the production of fluoropolymers and coolants are needed to help close the gaps in our understanding of emission sources and check that countries are fully compliant under different international climate and environment agreements," adds Stanley. "The collaboration with the Teflon manufacturer and the Dutch authorities was key to the success of our study," says Rust, who is now a research associate at the University of Bristol.
The tracer method developed by the researchers would be suitable for independent audits of factories and industrial areas – also for other gases, the scientists are convinced. Empa researchers are already planning another study in South Korea in October, in which they want to use the tracer method to determine the emissions of halogenated substances in the South Korean capital Seoul. "At the Cabauw measuring station, TNO will extend the monitoring of the GHG’s in the context of the European ICOS infrastructure with continuous monitoring of halogenated substances. This allows us to track the location and determine the emission of the sources of halogenated substances that were found to pass by the station during this experiment," adds TNO researcher Arnoud Frumau.
Journal
Nature
Method of Research
Experimental study
Subject of Research
Not applicable
Article Title
Effective realization of abatement measures can reduce HFC-23 emissions
Article Publication Date
21-Aug-2024
Pioneering study shows effective regulation and monitoring is key to tackling emissions of a super-greenhouse gas
image:
The measurements of HFC-23 and other by-products of Teflon manufacture, and of the emitted tracer gas were carried out at the Cabauw tall tower in the Netherlands. The 213-meter mast, as pictured, is operated by the Royal Netherlands Meteorological Institute (KNMI).
view moreCredit: ICOS RI
New research has revealed factories globally are not properly destroying one of the most potent greenhouse gases emitted from the production of fluoropolymers like Teflon, and refrigerants.
The study investigated a known disparity between real and reported emissions of this gas, prompting calls for more countries to sign up to official agreements to limit emissions and for their Teflon factories to be independently audited to ensure compliance.
The study, published today in the journal Nature, scrutinised emissions of one of the most potent hydrofluorocarbon (HFC) greenhouse gases called trifluoromethane, also known as HFC-23. Its main source is as a by-product in the industrial production of certain refrigerants and Teflon, which is used in products such as nonstick cookware. More than 150 countries have pledged to significantly reduce their HFC-23 emissions as part of the Kigali Amendment to the Montreal Protocol.
Since 2020, all Teflon manufacturers are obligated to destroy the strong greenhouse gas. According to the reports of the individual countries producing these products, this is happening. On paper the global annual emissions of HFC-23 were only 2,000 tons in 2020 but the actual global emissions, shown in numerous studies, uncover a different picture. In 2020 alone, around 16,000 tons of the greenhouse gas were found to be released into the atmosphere.
To unravel this discrepancy, researchers from the University of Bristol in the UK, Empa in Switzerland, and the Netherlands Organisation for Applied Scientific Research compared HFC-23 levels reported by individual countries with actual levels emitted from a Teflon factory in the Netherlands. To record the emissions as comprehensively and accurately as possible, a novel technique was used. This involved releasing a tracer directly next to the factory: a non-toxic gas that does not occur in the atmosphere and decomposes within a few weeks. At a distance of around 25 kilometres, they then measured the concentrations of HFC-23 and other by-products of Teflon manufacture – and also the concentration of the tracer.
First author Dr Dominique Rust, a Research Associate at the University of Bristol, said: “Since we knew exactly how much tracer we had released and how much of it arrived at the measuring point, we were able to calculate the emissions of HFC-23 and other gases.”
Results showed that even though estimated emissions are higher than those reported by the factory, measures to curb HFC-23 levels are largely effective.
Dr Rust, who worked on the study as part of her doctorate at Empa, the Swiss Federal Laboratories for Materials Science and Technology, added: “The collaboration with the Teflon manufacturer and the Dutch authorities was key to understanding the real picture.”
Co-author Dr Martin Vollmer, Researcher at Empa, said: “We suspect higher actual readings in the global atmosphere are explained by some countries underreporting emissions, resulting in this disconnect. One explanation is that abatement technologies aren’t as effectively implemented globally as at the factory we investigated."
The researchers are calling for factories to be independently audited. This independent verification of greenhouse gas emissions from the production of fluoropolymers and refrigerants would help close gaps in understanding the emission sources and check that countries are fully compliant under different international climate and environment agreements.
Co-author Dr Kieran Stanley, Senior Research Fellow at the University of Bristol, said: "Studies like this can help us to independently verify reported declines in emissions from fluorochemical plants and ensure that countries are reaching their obligations under the Kigali Amendment to the Montreal Protocol.
"These results are therefore really encouraging and show that abatement of emissions from fluorochemical plants producing fluoropolymers like Teflon can significantly reduce emissions of a highly potent greenhouse gas.”
The researchers are now planning another study in South Korea in October which will involve using the tracer method to determine the emissions of other halogenated substances in the capital city Seoul.
The measurements of HFC-23 and other by-products of Teflon manufacture, and of the emitted tracer gas were carried out at the Cabauw tall tower in the Netherlands. The 213-meter mast, as pictured, is operated by the Royal Netherlands Meteorological Institute (KNMI).
Credit
ICOS RI
Journal
Nature
Subject of Research
People
Article Title
'Effective realization of abatement measures can reduce HFC-23 emissions'
Article Publication Date
21-Aug-2024
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