S082013 An investigation of nitrogen compounds formation mechanism in O_2/CO_2 coal combustion and application to ultra-low NOx emission

In this study, pulverized coal was combusted in air and O_2/CO_2 atmosphere, and characteristic of nitrogen compounds formation in fuel-rich condition was investigated. In O_2/CO_2 coal combustion, more NO was formed than in air combustion, contrastively less HCN was formed. Comparing the sum of NO and HCN, O_2/CO_2 coal combustion emitted less amount of nitrogen compounds in fuel-rich condition. HCN is expected to be oxidized in second stage of combustion and converted to NO. Finally, less amount of NO is expected to emit in O_2/CO_2 coal combustion because of less amount of nitrogen compounds.