Noboru Tanikawa* and Kohei Urano**

*Tokyo Metropolitan Research Institute for Public Cleansing
**Yokohama National University

+ Correspondence should be addressed to Noboru Tanigawa:
Tokyo Metropolitan Research Institute for Public Cleansing
(3 Yumenoshima, Koto-ku, Tokyo 136 Japan)

Abstract

Characteristics of continuous analyzers for SO2 in flue gas (SO2 analyzers) were investigated in municipal incinerators. The investigated SO2 analyzers were the non-dispersive infrared absorption (NDIR) type and ultraviolet absorption (UV) type. The reasons for the difference between the observed values of the SO2 analyzers by NDIR and UV were thought to be the influence of coexistent CO2 and H2O condensation efficiency. The reasons why the observed values of the SO2 analyzer by NDIR were different from the precipitation titration method in the range of about -5 ppm and +4 ppm, were thought to be as follows: the influence in CO2, the difference in H2O condensation efficiency, the difference of measured species in the two methods, and absorption loss of SO2 into the condensed water. Especially, it may be very influential that not only SO2 but also SO3 is measured by the precipitation titration method. The reasons why the observed values of the SO2 analyzer by UV were about 4 ppm smaller than the observed values of the precipitation method were thought to be as follows: the difference of measured species in the two methods, and absorption loss of SO2 into the condensed water.

Key words: SO2 analyzer, infrared absorption, ultraviolet absorption, precipitation titration, municipal incinerator