煤气化飞灰流态化改性与再气化特性试验研究  

Experimental study on fluidized modification and regasification of gasification fly ash

作　　者：梁晨 褚福浩 任强强[1,2] 王小芳 LIANG Chen;CHU Fuhao;REN Qiangqiang;WANG Xiaofang(Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China)

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

出　　处：《洁净煤技术》2021年第3期116-122,共7页Clean Coal Technology

基　　金：国家自然科学基金资助项目(U1810127)。

摘　　要：随着煤化工技术的兴起,煤气化飞灰的资源化处理成为急需解决的“卡脖子”问题。利用商业流化床气化飞灰在15 kg/h改性气化试验台上进行试验,研究了流态化改性对气化飞灰形貌特性和灰熔融特性的影响以及改性飞灰的再气化特性。结果表明:利用流化态改性可实现气化飞灰在1200℃下的再气化。气化飞灰经流态化改性后,由于热破碎和残炭的气化反应具有清理孔隙和促进孔隙生成作用,使颗粒总孔体积和比表面积升高,同时改性气化剂水蒸气和氧气浓度的增加会进一步促进改性飞灰孔隙特性的改善。另一方面气化飞灰经流态化改性后,灰分矿物质中高熔点组分陨硫钙石转化为熔点较低的硬石膏,使灰熔融温度降低,灰分黏温曲线更平缓,临界黏度温度降低。在改性飞灰的再气化过程中,与900℃流态化改性过程相比,在下行气化炉1200℃,通过水煤气反应改性飞灰明显气化,有效气CO+H2产率达0.29 m^(3)/kg,系统碳转化率达71.2%。With the rise of coal chemical technology,the resource treatment of coal gasification fly ash has become an urgent problem.The gasification fly ash from commercial fluidized bed gasifier was tested on 15 kg/h modified gasification test rig to study the effects of fluidization modification on the morphological properties and ash fusibility of gasification fly ash and the regasification characters of modified fly ash.The results show that the regasification of gasification fly ash at 1200℃can be achieved by fluidized modification.After the fluidized modification,the total pore volume and specific surface area of fly ash are improved because the crack and gasification reactions of residual carbon have the effect of cleaning and promoting the formation of pores.The pore characteristics of modified fly ash can be further improved with the increase of steam and oxygen concentration of modification gasifying agent.On the other hand,after the fluidized modification of gasification fly ash,due to the transformation of high melting point component of the ash minerals into anhydrite with low melting point,the ash fusion temperatures of gasification fly ash decrease,the viscosity-temperature curve becomes smoother and the temperature of critical viscosity reduces.Compared with the fluidized modification at 900℃,the modified fly ash is obviously gasified by water gas reaction in the down-flow gasifier at 1200℃,and the yield of effective gas CO+H2 increases to 0.29 m^(3)/kg and the system carbon conversion increases to 71.2%.

关 键 词：气化飞灰 流态化改性 灰熔融特性 再气化利用 

分 类 号：TQ536.4[化学工程—煤化学工程]