Role of iron-based catalysts in reducing NO_(x) emissions from coal combustion  

作　　者：Yuehua Liu Lili Chen Shoujun Liu Song Yang Ju Shangguan 

机构地区：[1]State Key Laboratory of Clean and Efficient Coal Utilization,Taiyuan University of Technology,Taiyuan 030024,China [2]Shanxi Engineering Center of Civil Clean Fuel,Taiyuan University of Technology,Taiyuan 030024,China [3]College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan 030024,China

出　　处：《Chinese Journal of Chemical Engineering》2023年第7期1-8,共8页中国化学工程学报（英文版）

基　　金：supported by National Natural Science Foundation of China(21878210);Shanxi Provincial Science and Technology Achievement Transformation Guidance Special Program of China(202104021301052);Shanxi Province Patent Transformation Special Program Project(202202054).

摘　　要：Nitrogen oxide(NO_(x))pollutants emitted from coal combustion are attracting growing public concern.While the traditional technologies of reducing NO_(x) were mainly focused on terminal treatment,and the research on source treatment is limited.This paper proposes a new coal combustion strategy that significantly reduces NO_(x) emissions during coal combustion.This strategy has two important advantages in reducing NO_(x) emissions.First,by introducing iron-based catalyst at the source,which will catalyze the conversion of coke nitrogen to volatile nitrogen during the pyrolysis process,thereby greatly reducing the coke nitrogen content.The second is de-NO_(x) process by a redox reaction between NO_(x) and reducing agents(coke,HCN,NH_(3),etc.)that occurred during coke combustion.Compared to direct combustion of coal,coke prepared by adding iron-based catalyst has 46.1% reduction in NO_(x) emissions.To determine the effect of iron-based additives on de-NO_(x) performance,demineralized coal(de-coal)was prepared to eliminate the effect of iron-based minerals in coal ash.The effects of iron compounds,additive dosages,and combustion temperatures on de-NO_(x) efficiency are systematically studied.The results revealed that the NO_(x) emission of the coke generated by pyrolysis of de-coal loaded with 3%(mass)Fe_(2)O_(3) decreases to 27.3% at combustion temperature of 900℃.Two main reasons for lower NO_(x) emissions were deduced:(1)During the catalytic coal pyrolysis stage,the nitrogen content in the coke decreases with the release of volatile nitrogen.(2)Part of the NO_(x) emitted during the coke combustion was converted into N_(2) for the catalytic effect of the Fe-based catalysts.It is of great practical value and scientific significance to the comprehensive treatment and the clean utilization process of coal.

关 键 词：NO_(x) Coal combustion Coal pyrolysis Fe2O3 catalyst 

分 类 号：TQ536[化学工程—煤化学工程] X701[环境科学与工程—环境工程] TQ426