Kenji Yasuda*, Michimasa Takahashi*, Iwao Yajima* and Mikihiro Kaneko*

*Environmental Research Center of Kanagawa Prefecture

+ Correspondence should be addressed to Kenji Yasuda:
(842 Shimojuku, Nakahara, Hiratsuka 254 Japan)

Abstract

N2O formation and emission behaviors under various conditions as a result of combustion experiments of sewage sludge were examined. As a result of this research, it was ascertained that nitrous oxide was mainly formed by both homogeneous reactions through NCH/NCO and heterogeneous reactions from the direct conversion of char-nitrogen. Maximum N2O formation occurred around 700*C[Celsius degeree]. At a temperature higher than 800*C[Celsius degeree], the destruction of N2O rapidly occurred with regard to temperature and gas residence time. Following, the emission behaviors of N2O from sewage sludge incinerators were measured. The process of N2O formation as a result of these measurements could be confirmed. It was suggested that the direct conversion of char-nitrogen may play a major role in N2O formation with regard to sewage sludge incinerators.

Key words: nitrous oxide, emission behavior, formation, destruction, sludge incineration