Waste water combustion in laboratory swirl burners—II. No formation from dissolved N-compounds

Abstract

In a series of three papers we report on laboratory experiments on waste water combustion with dissolved N- and S-compounds sprayed into a confined swirl flame. The aims are to measure the NO formation under various operating conditions and to study the interactions of NO and SO 2 formation in flames with water injection. In the first paper of this series we report on the experimental equipment, the diagnostics and the burning conditions applied to study the waste water combustion in two different laboratory burners. In the present paper the results obtained from dissolved N-containing chemical compounds [CH 3NH 2, C 2H 7NO, C 6H 11NO, CO(NH 2) 2 and C 2H 6N 2O] sprayed into the flame are presented. The NO formation resulting from water-borne as well as gaseous N-compounds was measured. The conversion rate depends mainly on the flame properties (temperature, equivalence ratio, and residence time) and not significantly on the chemical structure of the chemicals used. It is possible to summarize parts of the experimental results by applying the semi-empirical theory of Fenimore, developed to describe the fuel-N problem in laminar flat flames. It seems to be important 6the Arrhenius-type temperature dependence of the measured NO max values is comparable to Fenimore's results down to temperatures of about 1500 K. At lower temperatures the values obtained seem to be nearly independent of temperature and the equivalence ratio.