摘要
通过固定床程序升温汞脱附试验系统对所选高硫煤泥中汞排放特性进行在线监测,并利用热重分析仪对煤泥热解和燃烧特性进行研究,结合试验所得热解和燃烧特性参数,采用分布活化能模型,进行动力学分析。结果表明:煤泥的热解和燃烧过程可分为3个阶段,非等温条件下,随着升温速率增加,热解过程在高温区发生,最大失重率提升,对应峰值温度偏移,产生热滞后,利于挥发分析出;在煤泥热解过程中少量氧气的参与,抑制挥发分的析出,在7%O_(2)条件下综合热解特性参数值D最大。热解性能随CO_(2)浓度升高而得到改善;煤泥燃烧性能随升温速率的增加而得到加强,其活化能随转化率变化呈现"U"型趋势分布;煤泥中无机汞化合物主要为HgCl_(2)、α-HgS、HgSO_(4)以及硅铝酸盐类结合汞,总汞释放主要范围对应200~600℃;煤泥中汞释放量随O_(2)浓度增大,CO_(2)气氛条件下,随着CO_(2)浓度增加,总汞释放量逐渐增大。
On-line monitoring of mercury emission characteristics from coal slime was carried out by afixed bed temperature programmed mercury desorption test system, and pyrolysis and combustioncharacteristics of high sulfur coal slime were studied by thermogravimetric analyzer. Combined with thepyrolysis and combustion characteristic parameters obtained from the experiment, the kinetic analysis wascarried out by using the distributed activation energy model. The results show that the pyrolysis andcombustion process of coal slime can be divided into three stages. Under non-isothermal conditions, withthe increase of heating rate, the pyrolysis process occurs in the high temperature region, and the maximumweight loss rate increases. The corresponding peak temperature shifts, resulting in thermal hysteresis,which is conducive to the precipitation of volatiles;The participation of a small amount of oxygen in thepyrolysis process of coal slime inhibits the precipitation of volatiles, and the comprehensive pyrolysischaracteristic parameter D is the largest under the condition of 7% O_(2). Pyrolysis performance improvedwith increasing CO_(2) concentration;The combustion performance of coal slime is strengthened with the increase of heating rate, and the activation energy shows a ‘U’ trend distribution with the change ofconversion rate;Inorganic mercury compounds in coal slime are mainly HgCl_(2) α -HgS, HgSO_(4) andsilicoaluminate bound mercury, and the total mercury release ranges from 200°C to 600°C;The release ofmercury in coal slime increased with the increase of O_(2) concentration. Under CO_(2) atmosphere, the totalmercury release gradually increased with the increase of CO_(2) concentration.
作者
郭晋荣
程鹏
贾里
郭婧楠
王彦霖
张永强
乔晓磊
樊保国
GUO Jinrong;CHENG Peng;JIA Li;GUO Jingnan;WANG Yanlin;ZHANG Yongqiang;QIAO Xiaolei;FAN Baoguo(College of Electrical and Power Engineering,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China)
出处
《化工进展》
EI
CAS
CSCD
北大核心
2021年第S02期411-420,共10页
Chemical Industry and Engineering Progress
基金
国家自然科学基金(U1510129,U1910214)
山西省高等学校科技创新项目(2020L0073)。
关键词
煤泥
固定床
燃烧
反应动力学
脱附
汞排放
coal slime
fixed-bed
combustion
reaction kinetics
desorption
mercury emissions
