Document 2JBvZL9YNw4oOLYGZn3j8kRrb

EPA's finding that the extremely low ID/F standards it set are achievable for the lime industry using untested ACI technology was unreasonable, and thus the technology should be deemed unavailable. Organic Hazardous Air Pollutant (olIAP) Emissions EPA has also set an extremely low standard for oIIAPs. Emission of these pollutants can vary widely, even in a single kiln, due to differences in the raw materials and fuels used. Even with very low emissions and acceptable risk with an ample margin of safety an unusual "spike" of one organic material could cause exceedance of the oIIAP standard even when treatment technology is in use. Regenerative Thermal Oxidation (RTO) is the control technology that EPA states would be used to control oITAP emissions. RTOs have not been installed on any lime kiln in the United States for oITAP control. RTOs have multiple technical issues which make their use impractical and technically infeasible. For example, sulfur dioxide (SO2 ) in the kiln exhaust may need to be removed by a wet scrubber to prevent oxidation of SO, to SO3 in the RID combustion chamber and creating acid mist and visible emissions. Most lime kilns do not currently utilize a wet scrubber. The normal maximum RTO operating temperature is between 1600 and 1700 degrees F. Thus, the flue gas from a lime kiln will need to be reheated following the cooling gas treatment for 171E described above. Given the need to scrub the exhaust gas to remove SO, before the RTO, a large amount of clean fossil fuel energy (e.g., natural gas) will be required to reach the R-I-0 minimum operating temperatures. Many lime plants may have insufficient or unavailable supplies of natural gas to support the use of an RTO. This will require adding infrastructure at additional and substantial cost. In some cases, new natural gas pipelines would need to be constructed and permitted, and casements obtained to bring the fuel to the lime plant across private or public lands or national forests. An R-I-0 will also require additional power demand and infrastructure that may not be available at a given lime plant. An RTO will also require permitting. Thus, at present, it has not been established that effective technology is available to implement the standards EPA set for oI IAPs. Hydrogen Chloride (HCI) To treat I IC1, EPA finds that lime plants will need to use dry sorbent injection (DSI), in which lime product is injected into the kiln gases to remove I ICI. While this technology has been used in other industries to treat HCI, prior to EPA's final rule it was not in use in the United States at any lime kiln. This means that EPA's projections of the feasibility and costs of using this technology were not based on data from lime kilns, and thus arc speculative.' 3 In its comments on EPA's proposed rule, NI,A pointed out that EPA should not attempt to set MACT floor standards where no sources were actually controlling for the pollutant in (continued .) 5 Sierra Club FOIA 2025-EPA-04883 ED_018388_00000249-00005 SC_EVERSPLIT0006021