Project Overview
NTH met with representatives of Indeck-Niles, LLC to discuss air permitting requirements for a new natural gas combined-cycle electric baseload plant. The new power plant consisted of two natural gas-fired CTGs, two HRSGs equipped with natural gas-fired duct burners, one steam turbine generator, and ancillary equipment. NTH developed air emission estimates for several operational scenarios, including various equipment manufacturers and ambient conditions, baseload operation, and startup and shutdown.
The permit application also included a detailed review of applicable state and federal air quality regulations, an extensive air pollution control technology evaluation, and an ambient impact analysis.
Project Scope
As part of air pollution control technology evaluation, NTH performed an in-depth review of NOx, CO, and VOC BACT limits and averaging periods on the combined-cycle CTGs to allow for optimal operational flexibility and ensure future compliance both various operating conditions. We reviewed SCR and oxidation catalyst performance at numerous similar sources nationwide, in support of proposed BACT limitations, which were accepted by EGLE. NTH also provided theoretical cost information for PM, SO2, and CO2 control technology on natural gas CTGs at the request of EGLE, although there is no current application of these controls on gas CTGs.
Finally, NTH performed an ambient impact analysis to demonstrate compliance with air quality standards and increments using computational models through the use of accepted guidance and methodology. NTH also developed an assessment for secondary formation of PM2.5 and ozone emissions and an additional impact analysis.
During biweekly calls, NTH worked closely with EGLE during permit review to allow for timely permit approval. NTH provided feedback to EGLE on draft permit conditions regarding regulatory consistency and operational flexibility. Within a few weeks after the close of the public comment period, MDEQ issued the permit with insignificant changes.
In 2022, NTH assisted Indeck with various changes to the construction permit, including removal of requirement for continuous emissions monitoring systems (CEMS) at the auxiliary boiler, and adjusting the capacities (heat input or horsepower) of the auxiliary boiler, fuel heaters, and emergency engine. The permit application included a full re-review of the PSD requirements, including BACT for each unit and comprehensive dispersion modeling.
Client Benefit
NTH’s experience in air permitting for power generation includes an in-depth understanding of operational complexities, permit flexibility to ensure future compliance, and proper implementation of applicable air permitting analyses, regulations, and accepted guidance. NTH negotiated removal of the NOx CEMS for the auxiliary boiler, saving Indeck costs associated with operations and maintenance, as well as emissions testing and reporting requirements.
