Conversions of fuel-N, volatile-N, and char-N to NO and N_2O during combustion of a single coal particle in O_2/N_2 and O_2/H_2O at low temperature  

作　　者：Yuan Li Hao Zhou Ning Li Runchao Qiu Kefa Cen 

机构地区：[1]State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University

出　　处：《Chinese Journal of Chemical Engineering》2018年第9期1967-1977,共11页中国化学工程学报（英文版）

基　　金：Supported by the National Basic Research Program of China(2015CB251501);the Innovative Research Groups of the National Natural Science Foundation of China(51621005)

摘　　要：Oxy-steam combustion is a promising next-generation combustion technology.Conversions of fuel-N,volatile-N,and char-N to NO and N2O during combustion of a single coal particle in O2/N2and O2/H2O were studied in a tube reactor at low temperature.In O2/N2,NO reaches the maximum value in the devolatilization stage and N2O reaches the maximum value in the char combustion stage.In O2/H2O,both NO and N2O reach the maximum values in the char combustion stage.The total conversion ratios of fuel-N to NO and N2O in O2/N2are obviously higher than those in O2/H2O,due to the reduction of H2O on NO and N2O.Temperature changes the trade-off between NO and N2O.In O2/N2and O2/H2O,the conversion ratios of fuel-N,volatile-N,and char-N to NO increase with increasing temperature,and those to N2O show the opposite trends.The conversion ratios of fuel-N,volatile-N,and char-N to NO reach the maximum values at 〈O2〉=30 vol%in O2/N2.In O2/H2O,the conversion ratios of fuel-N and char-N to NO reach the maximum values at 〈O2〉=30 vol%,and the conversion ratio of volatile-N to NO shows a slightly increasing trend with increasing oxygen concentration.The conversion ratios of fuel-N,volatile-N,and char-N to N2O decrease with increasing oxygen concentration in both atmospheres.A higher coal rank has higher conversion ratios of fuel-N to NO and N2O.Anthracite coal exhibits the highest conversion ratios of fuel-N,volatile-N,and char-N to NO and N2O in both atmospheres.This work is to develop efficient ways to understand and control NO and N2O emissions for a clean and sustainable atmosphere.Oxy-steam combustion is a promising next-generation combustion technology.Conversions of fuel-N,volatile-N,and char-N to NO and N_2O during combustion of a single coal particle in O_2/N_2and O_2/H_2O were studied in a tube reactor at low temperature.In O_2/N_2,NO reaches the maximum value in the devolatilization stage and N_2O reaches the maximum value in the char combustion stage.In O_2/H_2O,both NO and N_2O reach the maximum values in the char combustion stage.The total conversion ratios of fuel-N to NO and N_2O in O_2/N_2are obviously higher than those in O_2/H_2O,due to the reduction of H_2O on NO and N_2O.Temperature changes the trade-off between NO and N_2O.In O_2/N_2and O_2/H_2O,the conversion ratios of fuel-N,volatile-N,and char-N to NO increase with increasing temperature,and those to N_2O show the opposite trends.The conversion ratios of fuel-N,volatile-N,and char-N to NO reach the maximum values at b O_2N=30 vol%in O_2/N_2.In O_2/H_2O,the conversion ratios of fuel-N and char-N to NO reach the maximum values at b O_2N=30 vol%,and the conversion ratio of volatile-N to NO shows a slightly increasing trend with increasing oxygen concentration.The conversion ratios of fuel-N,volatile-N,and char-N to N_2O decrease with increasing oxygen concentration in both atmospheres.A higher coal rank has higher conversion ratios of fuel-N to NO and N_2O.Anthracite coal exhibits the highest conversion ratios of fuel-N,volatile-N,and char-N to NO and N_2O in both atmospheres.This work is to develop efficient ways to understand and control NO and N_2O emissions for a clean and sustainable atmosphere.

关 键 词：NO N2O Single coal particle O2/N2 O2/H2O Low temperature 

分 类 号：X701[环境科学与工程—环境工程] TQ038[化学工程]