热解气氛对准东煤中钠行为的影响及半焦结渣特性研究  

Effect of pyrolysis atmosphere on sodium behavior in Zhundong coal and study on slagging characteristics of char

作　　者：吕柯键 骆仲泱 方梦祥[1] 陈屹 岑建孟[1] LU Ke-jian;LUO Zhong-yang;FANG Meng-xiang;CHEN Yi;CEN Jian-meng(State Key Laboratory of Clean Energy Utilization,Zhejiang University,Hangzhou,310027,China)

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《能源工程》2022年第6期1-8,共8页Energy Engineering

基　　金：国家重点研发计划项目(2019YFE0100100-05);中央高校基本科研业务费专项资金资助项目(2021FZZX003-01-02)。

摘　　要：碱金属热解预处理是一种控制高碱煤燃烧灰问题的新思路,结合实验室煤炭分级转化多联产系统的实际热解气氛,利用水平管式炉对准东大成煤进行N_(2)、H_(2)、CH_(4)、CO_(2)及煤气气氛热解实验,探究热解气氛对钠迁移转化的影响。结果表明:与N2气氛相比,多联产气氛热解时钠释放量显著增加,发达的孔隙结构有利于钠的释放。N_(2)气氛热解半焦中被包覆的水溶钠占原煤总水溶钠的40%以上,通过孔结构表征推断中孔段堵塞是造成碳包覆的主要原因。多联产气氛下被包覆的水溶钠含量大幅减少,进而促进了钠释放以及钠长石(NaAlSi_(3)O_(8))、霞石(NaAlSiO_(4))等高熔点硅铝酸盐的生成,有利于碱金属热解预处理。利用结渣指数及灰熔点对比了原煤及煤气气氛热解半焦的结渣特性,证明热解预处理能有效降低煤焦的结渣倾向。Alkali metal pyrolysis pretreatment is a new idea to control the ash problem of high alkali coal.Combined with the pyrolysis atmosphere in coal polygeneration system of Zhejiang University,the pyrolysis experiments of N_(2),H_(2),CH_(4),CO_(2)and gas atmosphere were carried out in a tubular furnace to explore the effect of pyrolysis atmosphere on sodium behaviour.Compared with N2atmosphere,the release of sodium during pyrolysis in polygeneration atmosphere is significantly increased,and the developed pore structure is conducive to the release of sodium.The engulfed water-soluble sodium in N_(2)atmosphere pyrolysis char accounts for more than 40% of the total water-soluble sodium of raw coal.Based on the characterization of pore structure,it is inferred that the blockage of mesoporous section is the main reason for carbon engulfment.The content of engulfed water-soluble sodium under polygeneration atmosphere is greatly reduced,which promotes the release of sodium and the formation of high melting point aluminosilicates such as albite and nepheline,which is conducive to the pyrolysis pretreatment of alkali metals.The slagging characteristics of char and raw coal are compared by slagging index and ash melting point.It is proved that pyrolysis pretreatment can effectively alleviate the slagging tendency.

关 键 词：准东煤 热解 气氛 钠迁移转化 结渣特性 

分 类 号：TK01[动力工程及工程热物理]