Control of HFC-23 Emissions
Hydrofluorocarbon (HFC)-23 is a potent greenhouse gas with a 100-year global warming potential (GWP) of 14,800. While there are limited instances where HFC-23 is captured, purified, and used for commercial purposes, the majority of HFC-23 is unintentionally created as a byproduct during the production of certain fluorinated compounds, including hydrochlorofluorocarbon (HCFC)-22. While HCFC-22 is an ozone-depleting substance that has been phased out domestically under the Clean Air Act in line with the international phaseout occurring under the Montreal Protocol on Substances that Deplete the Ozone Layer, it can still be produced for use as a feedstock to make other chemicals, such as low-GWP hydrofluoroolefins (HFOs). These HFOs can be used in many of the same applications as high-GWP HFCs, so transitioning to them can reduce emissions of greenhouse gases.
Unless sold for a consumptive use, controlled, or captured and destroyed, such creation of HFC-23 is ultimately vented to the atmosphere where it contributes to climate change. HFC-23 is not an air toxic and does not pose a direct risk to local communities, but climate change does threaten the public health of the U.S. population and especially those that may be vulnerable based on their characteristics or circumstances (see sections III and IV of 86 FR 55116, October 5, 2021).
EPA established requirements for all entities producing HFC-23 to control these emissions (40 CFR 84.27). Specifically, EPA requires under 40 CFR 84.27 that no later than October 1, 2022, no more than 0.1 percent of HFC-23 created on a facility line may be emitted (including any HFC-23 emissions during transportation to and destruction at a different facility), as compared to the amount of chemical intentionally produced on the line. EPA estimates that from 2022 through 2050 these HFC-23 emission control requirements will have abated cumulative emissions of more than 7,000 metric tons of HFC-23 or more than 3.7 million metric tons of carbon dioxide equivalent annually, and result in net present cumulative benefits of $6.4 billion in 2020 dollars at a three percent discount rate (see Regulatory Impact Analysis for Phasing Down Production and Consumption of Hydrofluorocarbons (HFCs)). EPA also established a provision that allows chemical producers to request up to two six-month extensions of the compliance date.
One entity, Chemours Company FC, LLC, timely requested a six-month extension for its production facility in Louisville, Kentucky, due in part to supply chain difficulties that delayed acquisition of the necessary equipment to control HFC-23 emissions. EPA acknowledges that the primary purpose of the extension is to allow time to measure, validate, and optimize the effectiveness of the process change at the Chemours Louisville Works facility and that Chemours expects to complete this validation by the end of the year. The Agency granted this extension with the understanding that Chemours will have all necessary equipment onsite, operational, and effective by October 1, 2022, and will be running that equipment from that date onwards. With this understanding and our review of the submitted information, EPA has granted the request to extend the compliance date for HFC-23 emission control requirements at Chemours Louisville Works to April 1, 2023.
EPA is monitoring the facility’s progress on meeting the emission control requirements and intends to post status updates to this website as information becomes available for public release. This will help ensure interested stakeholders are aware of the facility’s current status and progress toward meeting the HFC-23 emission limit.
Requests for extension: 1
- Chemours Louisville Works
- Request for six-month extension granted
- New compliance date is April 1, 2023
- Federal Register Notice
- Letter granting the extension (pdf)
To view the public docket on http://www.regulations.gov, search for Docket ID number EPA-HQ-OAR-2022-0755.
Update from November 2022 meeting with Chemours:
Chemours confirmed in a meeting with EPA on November 22, 2022, that the HFC-23 control equipment continue to perform as expected and that progress is being made in validating compliance calculations. In November 2022, Chemours shipped its first railcar of AIM-regulated captured HFC-23 for off-site destruction and in early January 2023 should be able to verify whether the HFC-23 emission controls meet the regulatory requirements.
Update from October 2022 meeting:
Chemours confirmed in a meeting with EPA on October 21, 2022, that its Chemours Louisville facility has all the necessary HFC-23 control equipment onsite, operational, and effective, and continues to run the control equipment. In particular, the capture system is operational and off-site destruction is expected to begin later in calendar year 2022. Process data monitoring indicates that the system is performing as expected to meet the emission standard under 40 CFR 84.27. Monitoring remains ongoing as Chemours continues its system and data validation and optimization process, which will also include an overall compliance calculation that relies on summary data of ongoing site operations and destruction efficiency at the site performing the HFC-23 destruction, once volume levels have been met for shipping of the captured HFC-23. Chemours states that it remains confident in meeting or exceeding the 0.1% emission standard upon validation.