Primary Products Ingredients Americas LLC (d/b/a Primient) owns and operates a wet corn milling plant in Lafayette, Indiana. Primient operates two natural gas-fired stationary turbines ? designated as LA-84 and LA-85 ? both which utilize lean premix combustion technology. Neither turbine is equipped with an oxidation catalyst.
Primient is subject to the National Emission Standards for Hazardous Air Pollutants for Stationary Turbines (NESHAP YYYY), which establishes a formaldehyde emission limit of 91 parts per billion volume (ppbv). Compliance with this standard must be demonstrated through annual formaldehyde emission testing and continuous parameter monitoring. Facilities that do not utilize an oxidation catalyst with their turbines are required to petition the Administrator to propose an alternative parameter monitoring approach.
On August 23, 2022, Primient submitted its initial petition for alternative operating limits to the EPA. Following subsequent discussions, revised petitions were submitted on January 9, 2023, and again on September 7, 2023. To support the petition, formaldehyde emission testing was conducted on LA-84 on August 22, 2023. The testing aimed to demonstrate that the turbine could operate within the proposed load range of 0% and 100% while remaining in compliance with the formaldehyde emission standard. During the test, six sets of two 30-minute sampling runs were performed at turbine loads of 50%, 60%, 65%, 70%, and 85%. All sets, except one conduct