煤粉富氧燃烧烟气中飞灰固硫特性试验  

Experiment of sulfur retention characteristics of fly ash in pulverizedcoal oxy-fuel-firing flue gas

作　　者：张健[1] 曹瑞杰 ZHANG Jian;CAO Ruijie(School of Environment and Architecture Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;Shanghai Institute for Design and Research on Environmental Engineering,Shanghai 200232,China)

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]上海环境卫生工程设计院有限公司,上海200232

出　　处：《洁净煤技术》2023年第8期102-108,共7页Clean Coal Technology

基　　金：上海市浦江人才计划资助项目(16PJ1407800)。

摘　　要：富氧燃烧工艺的烟气中富含CO_(2),同时SO x浓度也有一定变化。研究了不同煤种飞灰在富氧燃烧烟气中的固硫机理。在高温沉降炉中,测试了6种典型煤粉飞灰在空气燃烧烟气和富氧燃烧烟气中的固硫过程,分析了影响因素。结果表明:烟煤灰样固硫量很少,与烟煤灰中缺少碱土金属(Ca、Mg)有关;褐煤飞灰固硫现象显著。褐煤灰在空气燃烧下的固硫率为43%,在富氧燃烧条件下灰固硫率提高至60%。在富氧气氛下,1000℃灰固硫速率明显高于800℃;飞灰固硫的温度窗口及反应效果与SO_(2)氧化生成SO_(3)的反应一致。灰中部分碱土金属会与Si、Al等结合,这部分碱土金属不具备固硫活性。SO_(3)生成与灰中Fe_(2)O_(3)催化、碱土金属固硫有关。发展富氧燃烧与Ca基干法脱硫的协同技术,对于实现炉内烟气的深度SO x减排有应用价值。During the oxy-fuel combustion,rich CO_(2) is produced in flue gas with varied SO_(x) concentration.In this paper,the characteristics of sulfur retention in fly ash from different coal in oxy-fuel combustion was studied.The SO x absorption in fly ashes of six coals was tested on the high-temperature drop-tube furnace,in which the flue gas atmosphere set for oxy-fuel or air burning.The influencing factors were analyzed.The results show that the sulfur retention amount is very low in bituminous coal ash,which is related to the lack of alkaline earth metal(Ca,Mg)in bituminous coal ash.However,the sulfur retention of lignite ash is significant.The fixed sulfur efficiency is about 43%for lignite ash after air-firing,as compared with 60%after its oxy-fuel combustion.The sulfur absorption rate is much higher in oxy-fuel flue gas in 1000℃rather than in 800℃.The temperature window and reaction effect of fly ash sulfur fixation are consistent with the reaction of SO_(2) oxidation to SO_(3).Some alkaline earth metals have combined with Si or Al,etc.,and these alkaline earth metals do not have sulfur fixation activity.SO_(3) formation is effected by both catalytic effect of Fe_(2)O_(3) and the sulfur-retention behavior in ash.Through both oxy-fuel combustion and dry scrubbing of Ca sorbent added together,it is promising to control SO x emission deeply in furnace.

关 键 词：富氧燃烧 褐煤 飞灰 固硫 硫氧化物 

分 类 号：TQ534[化学工程—煤化学工程] X51[环境科学与工程—环境工程]