Engineer, model and supply new NOx reduction system

The Challenge

RJM was tasked to engineer, model, supply and start-up a NOx reduction system including burner modifications and an SNCR system to reduce NOx emissions by 53% to 0.20 lb/mmBtu, in order to meet Phase 1 RACT regulations.

The plant, owned and operated by Northeast Utilities, consisted of a 172 MW unit manufactured by Combustion Engineering, with a tangential twin furnace firing oil.

 RJM Solution

RJM performed burner modifications which included flame stabilizers and new fuel/air nozzles. Secondary airflow balancing was also done utilizing RJM’s ADA technology.

RJM also designed, modeled and supplied the major equipment, as well as optimising the commercial SNCR System. The NOxOut SNCR System included a common storage tank and circulation. The dual zone metering module was provided to meter the proper amount of chemical and dilution water to the system from 25% – 100% load. The unit has two levels of injectors with six wall injectors at the lower level and six wall injectors at the upper level.

Results

NOx reductions of 20% were achieved reducing NOx emissions to 0.20 lb/mmBtu at full load conditions. Ammonia slip measurements were less than 5 ppm as measured at the air heater inlet. NOx emissions were reduced by a total of 53% with the combination of burner modifications and the SNCR System.