Technical Bulletin No. 0802: Effect of Stripper Off-Gas Burning on NOx Emissions

Tests were conducted to (1) determine the ammonia content of kraft pulp mill condensates sent to steam strippers; (2) quantify the efficiency of steam strippers in stripping condensate ammonia; (3) study the effect of burning stripper off-gases (SOGs) on NOx emissions from lime kilns, boilers, and thermal oxidizers; (4) correlate any NOx emission increases to the amount of ammonia present in SOGs and operating parameters such as combustion temperature and oxygen level in the combustion zone; and (5) measure NOx emissions from thermal oxidizers burning low volume, high concentration noncondensible gases (LVHC NCGs). The ammonia content of the condensates in the study ranged from 94 to 508 mg/L and ammonia was almost completely stripped from the condensates. However, the fraction of ammonia in SOGs that was oxidized to NOx ranged from 6.