Creative Approach, Thoughtful Analysis Saves Two Coal Plants

“Neundorfer combined its analytical process with its application experience to identify low-cost approaches that would achieve MATS compliance.”

When the plant’s initial assessment indicated MATS compliance would require high-cost upgrades, the future of two plants was uncertain. By modeling improvements over the entire process, Neundorfer identified a low-cost compliance program that would ensure these plants continue to meet their operational goals long into the future.

A large Midwestern utility was in the midst of a dilemma. They were struggling to figure out how to keep two coal-fired power plants economically viable while meeting upcoming Mercury Air Toxics Standard (MATS) requirements. Though not the largest in their fleet, these plants were essential as they possessed great flexibility and reliability in power production.

The company had a plethora of options, yet it became evident that there were only two viable paths: convert to natural gas or invest in new air pollution control equipment. Natural gas was abundant but the cost of infrastructure improvements took this option off the table.  If the plants continued to burn coal, meeting the new MATS PM and Mercury emissions limits seemed to require expensive new air pollution control equipment.

Determined to find a solution that kept the plants viable, Neundorfer studied the operation of the boilers and precipitators to determine if there was an alternative, low-cost approach that would achieve MATS compliance. Neundorfer combined its analytical process with its application experience to uncover the possibilities.

Neundorfer’s process involved looking at boiler, precipitator and emissions operating data and utilizing computer-aided performance modeling tools. Their main focus was to identify the variables that influenced performance, and how. Upon completion of the analysis, stakeholders from the plants and corporate offices reviewed the data with Neundorfer to determine the most cost-effective approach. In the end, modifications were selected, a schedule was developed, and budgets were drafted.

Neundorfer used its in-house gas flow and fluid dynamics modeling capabilities to help evaluate improvement options. The solutions focused on improving the areas of each unit that would yield the best performance, concentrating on optimizing corona power input, reducing the re-entrainment of fly ash and optimizing gas flow velocity. This approach allowed Neundorfer to ensure that the long-term reliability and sustainability of key components were addressed in the solution.

Mercury capture was another factor that garnered serious consideration. Existing flue gas conditioning systems were successful at improving the ability of the precipitators to collect fly ash, however, they hampered the ability of the carbon injection systems to remove mercury. There was some concern that a proprietary chemical injection would be necessary to modify resistivity. Yet, once the solution was implemented, the chemical was not needed in one unit, and the other two units required much less of the chemical than anticipated. As a result, the units achieved a substantial reduction in operating costs.

Recognizing that meeting compliance doesn’t end with the completion of a project, the customer and Neundorfer implemented a program aimed at assisting plants to manage and optimize their upgraded systems. The program created a partnership with key operating personnel and combined automatic transfer of real-time, key operating parameters with an analytical process consisting of computer modeling and technical resources.

The program has been extremely successful in keeping the plants operating well below their required limits and has given them the power to react quickly to developments that would have otherwise caused operational issues in the past. Furthermore, the two plants remain a part of the economic fabric of their communities, providing jobs and reliable electricity.