The first type involves modification of the combustion process (staged combustion) and includes low-NOx burners (with and without overfire air [OFA]) and gas or coal reburning; these methodologies are described in this section. The second type of NOx reduction strategy involves postcombustion removal and includes selective noncatalytic NOx reduction (SNCR), selective catalytic reduction (SCR), and combined SO2/NOx removal.

EPCON retrofits