湿氧化和热处理对煤基活性炭吸附SO_2的影响  

Effect of wet oxidation and heat-treatment on the SO_2 adsorption capacity for coal-based activated carbon

作　　者：单晓梅[1] 张文辉[2] 杜铭华[2] 朱书全[1] 

机构地区：[1]中国矿业大学(北京)化学与环境工程学院,北京100083 [2]煤炭科学研究总院北京煤化工研究分院,北京100013

出　　处：《煤炭学报》2004年第2期208-212,共5页Journal of China Coal Society

基　　金：国家"863"计划项目:可资源化烟气脱硫技术(2001AA527010-01)

摘　　要：HNO3和(NH4)2S2O8氧化改性煤基活性炭,通过热重分析确定最佳热处理温度,考察孔隙和表面含氧基团种类及不同温度热分解产生活性位对SO2吸附性能的影响.研究表明,氧化处理对SO2吸附影响不大.虽然氧化生成表面含氧基团增加了活性炭的表面极性,但活性炭表面酸性基团的增加不利于SO2吸附.而氧化样品在950℃高温处理后对SO2的吸附增加显著,且HNO3氧化样品热处理后吸附能力大于(NH4)2S2O8氧化和原样品的热处理后的吸附能力.由关联含氧基团的类型及热处理温度可发现,因HNO3氧化比(NH4)2S2O8氧化生成了较多的酚羟基,其热分解留下的活性位增强了对SO2的吸附,但这些活性位并没有因吸附SO2而消耗掉,样品解析后对SO2的可逆吸附量达98%以上.Coal-based activated carbon oxidized by HNO_(3) and (NH_(4))_(2)S_(2)O_(8) and followed by heating at the appropriate temperature based on TGA analysis were studied to investigate the relationship among the capacity of adsorption SO_(2),textural characteristic, surface chemistry.The results showed that oxide treatment has little influence on SO_(2) adsorption capacity, though the large quantity surface oxygenated groups increase surface polarity, the large quantity surface oxygenated groups increased surface acidity inhibite adsorption of SO_(2).950 ℃ heating treatment resultes in the uptake of SO_(2) increasing obviously especially on HNO_(3) oxidized carbons.As HNO_(3) oxidized increasing the large quantity surface function phenol compared with(NH_(4))_(2)S_(2)O_(8) oxidized,its decomposition leads to new active sites formation, this markedly promotes adsorption of SO_2.This adsorption is almost 98% reversible and therefore physical adsorption can't consume these active sites.

关 键 词：活性炭 氧化改性 热处理 SO2 

分 类 号：TQ424.1[化学工程]