刚玉床料对高钠煤循环流化床气化中钠迁移转化的影响  

The Influence of Corundum on Migration and Transformation of Sodium in High-Sodium Coal During Circulating Fluidized Bed Gasification

作　　者：齐晓宾 宋国良[1] 宋维健[1,2] 杨少波[1,2] 吕清刚[1] 

机构地区：[1]中国科学院工程热物理研究所,北京100190 [2]中国科学院大学,北京100049

出　　处：《工程热物理学报》2016年第10期2216-2224,共9页Journal of Engineering Thermophysics

基　　金：中国科学院战略性先导科技专项(A类;No.XDA07030100);国家国际科技合作专项(No.2014DFG61680)

摘　　要：选择刚玉作为床料,利用循环流化床对天池木垒煤进行了气化实验研究,研究了刚玉对失流的抑制作用、矿物元素在不同粒径颗粒中分布以及煤中Na经过气化反应后的迁移转化规律。研究结果表明,以刚玉作为床料会降低底渣表面包覆层黏性,避免颗粒聚团导致失流;在刚玉诱导下,煤中Al、Si、Ca、Fe、Na和Mg等绝大多数矿物质元素在底渣和循环灰中富集,并导致物料粒径不断增大;935℃床温下(以刚玉为床料),天池木垒煤中Na在底渣、飞灰和煤气中的分布率分别为39.6%、45.4%和15%,相对于以石英砂为床料的情形,刚玉有效抑制了Na的挥发,降低了尾部沾污发生的机率;在刚玉作用下,固留在底渣中的Na主要以NaAl_(11)17、NaAlSi_2O_6和NaAlSi_3O_8等形式存在,并且刚玉与煤中矿物质元素反应生成的物质具有较高的熔点,避免低温共熔现象发生。Gasification of Tianchimulei coal（TC） was conducted in a circulating fluidized bed with corundum as the bed material to investigate the role of corundum in controlling de-fluidization,the distribution of mineral elements in particles with different grain sizes and migration and transformation of sodium in coal during this process.The results show that the coating layer stickiness of bottom slag was decreased under the action of corundum,which avoided the occurrence of de-fluidization.Aluminum,silicon,calcium,iron,sodium and magnesium were enriched in bottom slag and circulating ash,leading to the size growth.At 935℃,corundum effectively restrained volatilization of sodium in TC,and the distribution ratios of sodium in bottom slag,fly ash and gas were 39.6%,45.4%and15%,respectively,which reduced the risk of fouling occurrence comparing to the case with quartz as bed material.Aluminum in corundum reacted with sodium in TC forming sodium aluminosilicates mainly in the form of NaAl（11）O（17）,NaAlSi2O6 and NaAlSi3O8.Aluminosilicates formed by reactions between corundum and mineral elements are of high melting temperatures,avoiding the formation of low-melting temperature eutectics.

关 键 词：刚玉 高钠煤 循环流化床 气化 钠 迁移转化 

分 类 号：TQ530.2[化学工程—煤化学工程]