Characteristics of continuous analyzers for nitrous oxide in flue gas from municipal incinerators

Abstract The accuracy of data obtained with a continuous N 2 O spectrophotometric analyzer, is compared with data from a laboratory gas chromatograph for emissions of N 2 O, a global greenhouse gas, from municipal incinerators. Associated CO 2 interfered with the determination by the N 2 O analyzers in the range ±1 ppm. The differences between the measured values by the N 2 O analyzer and the gas chromatograph depended on the level of interference from CO 2 . We confirm that the N 2 O analyzers are useful for the continuous determination of N 2 O in the flue gas from municipal incinerators if their characteristics are previously understood. The concentration of N 2 O in the flue gas from the municipal incinerators always varied in the range from a few ppm to ∼ 20 ppm. The concentration of N 2 O decreased when the concentration of NO x increased and increased when the concentration of NO x decreased. The ratio of N 2 O/NO x was in the range from ∼ 0.02 to 0.16 and increased with a decrease of NO x . The formation of N 2 O in the munieipal incinerator was considered to be dependent on the content of nitrogen in the waste and independent of the incineration temperature. Little N 2 O was formed by the TiO 2 -V 2 O 5 catalyst used for NO x reduction in the incineration facility although the formation of N 2 O in the laboratory has been reported.