摘要
利用固定床反应系统模拟活性焦烟气脱硫及再生过程,进行了10次循环的脱硫再生实验,测定、计算了活性焦硫容;借助XPS和SEM表征再生前后活性焦的表面化学及形貌,测定了活性焦77 K下N2的吸附/解吸等温线,并解析获得了活性焦的BET比表面积和孔容。结果表明,循环脱硫再生过程中活性焦的比表面积和孔容呈上升趋势,分别由312.3 m2/g和0.147 9 cm3/g增加至441.4 m2/g和0.203 0 cm3/g,与此同时表面O元素含量由15.63%逐渐增加至19.09%;随着孔容、比表面积、表面O含量的增加,活性焦的硫容由最初的101.29 mg/g下降至22.56 mg/g,前6个循环活性焦硫容与其表面O含量呈逆向相关关系。表面酸性的增强抑制了SO2在活性焦催化活性位的化学吸附,导致脱硫性能降低。
The experiments of desulfurization-regeneration（D-R） with commercial activated coke on a fixed-bed reac-tor in the simulated flue gas were conducted for ten cycles. The desulfurization capability of the activated coke was de-termined and calculated. Surface chemistry and morphology of the activated coke before and after regeneration werecharacterized by XPS（X-ray Photoelectron Spectroscopy） and SEM（Scanning Electronic Microscopy）,respectively.Adsorption / desorption isotherm of nitrogen at 77 K of the activated coke was plotted,and thus the BET specific areaand pore volume of the activated coke were obtained. Results show that with the proceeding of D-R cycle the BET spe-cific area and pore volume of the activated coke are on a rising trend,increasing from 312. 3 to 441. 4 m2/ g and from0. 147 9 to 0. 203 0 cm3/ g,respectively,meanwhile a gradual increase of oxygen content from 15. 63% to 19. 09% onsurface of the activated coke can be observed;an unfavorable decrease of the desulfurization capability from 101. 29 to22. 56 mg / g accompanied the increase of pore volume,BET specific area and surface oxygen content. During the firstsix D-R cycles there is an inverse relationship between the desulfurization capabilities and surface oxygen content onthe surface of the activated coke. It is the enhancement of acidity of surface that inhabits SO2 chemisorptions on the ac-tive sites,which results in the progressive loss of desulfurization ability.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2016年第3期751-759,共9页
Journal of China Coal Society
基金
煤炭科学技术研究院科技发展基金资助项目(2014JC01)
国家科技重大专项资助项目(2011ZX05041-004)
关键词
活性焦
脱硫
再生
孔结构
表面性质
activated coke
desulfurization
regeneration
pore structure
surface characteristics
