Noboru Tanikawa* and Kohei Urano**

* Tokyo Metropolitan Research Institute for Waste Management
** Laboratory of Safety and Environmental Engineering, Faculty of Engineering, Yokohama National University

+ Correspondence should be addressed to Noboru Tanikawa:
(2 Aomi, Koto-ku, Tokyo, 135 Japan)

Abstract

HCl and SO2 concentrations in flue gas from municipal waste incinerators were investigated for different removal equipment for HCl and SO2. The emitted and removed levels of HCl and SO2 from the municipal waste incinerators in the ward areas of Tokyo and throughout Japan were estimated. When the removal equipment was not used, the mean concentration of HCl ranged from 300 to 650 ppm. This range was dependent on the sorting and collection method of plastics in the waste, gas temperature control methods, and dust removal methods. The mean concentration of SO2 ranged from 44 to 63 ppm, and was dependent on dust removal methods. In the case where the calcium powder injection method and the electrostatic precipitator (EP) were adopted, the mean concentrations of HCl and SO2 ranged from 200 to 410 ppm, and 30 ppm, respectively. In the case where EP and a wet scrubber were adopted, the mean concentration of HCl ranged from 6 to 12 ppm, and the mean concentration of SO2 was about 2 ppm. In the ward areas of Tokyo, the amount of incinerated waste in 1994 increased by 1.4 times over that for 1980. However, the amount of HCl and SO2 that was emitted from municipal waste incinerators in 1994 was slightly higher than those in 1980 because of the adoption of removal equipments. In Japan overall, the emitted amount of HCl and SO2 from municipal waste incinerators in 1992 was estimated to be 9.1X104t/y and 1.8X104t/y, respectively. And the removed amount was estimated to be 7.6X104t/y and 2.0X104t/y, respectively.

Key words: municipal waste incineration, HCl, SO2, emission, flue gas treatment