摘要
为了考察预处理对褐煤后续热转化行为的影响,以内蒙古胜利褐煤为研究对象,分别在不同气氛和温度下对其进行热处理,并使用热重分析仪对预处理提质煤样进行CO2气氛下的热解气化研究。研究结果表明,在Ar,CO2气氛下热处理的褐煤表面的各类含氧官能团含量随其受热温度的升高逐渐减少,部分脂肪侧链断裂脱落,芳香氢有所增加;在空气气氛下热处理后,煤表面发生氧化,随着温度的升高,羟基减少,羧基、羰基以及醚键都逐渐增加,脂肪氢有所减少。在Ar,CO2气氛下预处理褐煤的热解、气化行为相差不大,而空气预处理后的褐煤有着较大的气化速率,最大气化速率温度也相应提前;预处理温度升高,会导致褐煤热解的起始温度推迟、热解速率减慢,以及在气化阶段最大失重率的略微增加。
In order to investigate the effects of pretreatment on further thermal conversion, a lignite from Shengli mine in China was used as an experimental coal sample and pretreated thermally under the conditions of various temperatures and gas medium in this study. The pyrolysis and gasification behaviors of pretreated lignite in CO2 were observed by using thermogravimetric analyzer and related with the structural changes of lignite before and after the pretreatment. The results show that various oxygen-containing groups and aliphatic-H decrease with increased temperature while aro- matic-H increased slightly in Ar and CO2. However, the oxygen-containing groups increase except for hydroxyl with the raised temperature due to the oxidation of lignite pretreated in air. Compared with lignite samples pretreated in Ar and CO2 with the similar pyrolysis and gasification reactivity, air-pretreated lignite has a higher gasification reaction rate and lower relevant temperature because of increasing reactive oxygen sites. As the pretreatment temperature rises, the initial temperature of pyrolysis delays, pyrolysis rate decreases and also the maximum loss of weight in gasification process increases slightly.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第2期463-469,共7页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2012CB214902)
国家国际科技合作专项资助项目(2013DFG61490)
关键词
褐煤
热处理
化学结构
热解
气化
lignite
thermal treatment
chemical structure
pyrolysis
gasification
