摘要
采用XPS对六枝(Liuzhi)和合肥(Zunyi)原煤及其固定床热解半焦表面的含碳官能团和硫迁移行为进行了研究。在氮气气氛下,在400℃～700℃合肥煤焦表面O=C-O,C-H和C-C含量与原煤相比,呈现下降趋势,而C=O和O-C-O、C-O含量却呈现增加趋势;六枝煤焦表面的O=C-O、C=O和O-C-O、C-O含量的变化规律与合肥煤相似,而C-H和C-C含量的变化却与合肥煤相反。在氢气气氛下,合肥煤焦表面不仅O=C-O含量与原煤相比下降,而且C=O和O-C-O、C-O含量也下降,但C-H和C-C含量却增加;六枝煤除了C=O和O-C-O含量下降外,其他官能团的变化与其在氮气气氛下相似。两种煤焦表面S/C比在氮气气氛下随着温度的升高而升高,氢气气氛下在400℃～600℃随着温度的升高却下降,700℃又显著升高。这说明在热解过程中硫在两种气氛下都能从体相向表面迁移,但是氢气能够和含硫自由基反应,所以氢气气氛下煤焦表面的S/C比率低于其氮气气氛下的。
Two Chinese coals,Liuzhi（LZ） and Zunyi（ZY）,were pyrolyzed in a fixed bed reactor under N2 and H2 atmospheres from 400 ℃ to 700 ℃.X-ray Photoelectron Spectroscopy（XPS） was used to study the changes of carbon-containing groups and sulfur transformation on the surface of coals and their chars.Under N2 atmosphere,on the ZY chars surface,the contents of O=C-O,C-H or C-C groups have a decreasing trend and the one of C=O or O-C-O,C-O is increasing compared with that of raw coal at all temperatures.For LZ coal,the changes of O=C-O,C=O or O-C-O,C-O contents are similar to ZY coal,however the one of C-H and C-C content is contrary to that of ZY coal.Under H2 atmosphere,for ZY coal,not only O=C-O content,but also C=O and O-C-O,C-O contents have a decreasing trend,while C-H and C-C contents increase compared with raw coal;for LZ coal,except for C=O and O-C-O content has a decreasing trend,and other carbonyl groups have the same trend as that under N2 atmosphere.And for these coals,with the temperature increasing,the S/C ratio on the char surface increases under N2 atmosphere,however the one decreases at the temperatures from 400 ℃ to 600 ℃ and increases much at 700 ℃ under H2 atmosphere.This indicates that under both atmospheres,sulfur can transfer from inner to the surface during pyrolysis,but hydrogen can react with sulfur-containing radicals,so the S/C is lower than that under nitrogen.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2011年第2期81-84,共4页
Journal of Fuel Chemistry and Technology
基金
The PH.D Project of Natural Science Foundation of Inner Mongolia(2009BS0606)
the Key Project of Natural Science Foundation of China(21006042)
关键词
含碳官能团
硫迁移
热解
XPS
carbonyl group
sulfur transformation
pyrolysis
XPS
