Carbon Monoxide Emissions from Chlorine Dioxide Bleaching, 1997 Environmental Conference Proceedings

Carbon monoxide (CO) is generated as a by-product of pulp bleaching with chlorine dioxide (C1O2 ). As C1O2 is substituted for chlorine (Cl,), CO emissions may increase in quantities sufficient to trigger Prevention of Significant Deterioration (PSD) permitting requirements.

Rayonier’s Jesup, Georgia, mill plans to increase the use of C1O2 in the first stage of a CEDED bleaching sequence. As a result of the concern for increased CO emissions, a testing program was conducted to monitor total bleach plant CO emissions with varying levels of C1O2 substitution and operating parameters in the first stage.

Test results indicated that total bleach plant CO emissions do not increase linearly with increased C1O2 usage in the first stage, but CO reaches a maximum rate. The chemistry and the kinetics of CO generation is not well understood; however, the data indicate that increasing C102 substitution in the first stage may shift the location of CO generation without significantly increasing total CO emissions. As a result of the evaluation program, it was possible to avoid PSD permitting for any potential increases in C1O2 substitution.