鸡粪对小麦秸秆燃烧过程中结渣影响的机理  

Mechanism of the effect of chicken manure on slagging during the combustion of wheat straw

作　　者：杨自强 李风海 马名杰 赵薇 刘雪飞 YANG Ziqiang;LI Fenghai;MA Mingjie;ZHAO Wei;LIU Xuefei(School of Chemistry and Chemical Engineering,Henan Polytechnical University,Jiaozuo 454000,China;School of Chemistry and Chemical Engineering,Heze University,Heze 274000,China)

机构地区：[1]河南理工大学化学化工学院,河南焦作454000 [2]菏泽学院化学化工学院,山东菏泽274000

出　　处：《煤炭学报》2023年第6期2378-2387,共10页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(21875059);山东省自然科学基金资助项目(2018MB034)。

摘　　要：双碳背景下,生物质作为煤炭资源的可替代清洁能源,其高效利用成为目前研究的热点。通常生物质的碱金属和碱土金属质量分数较高,在燃烧过程中易造成结渣、堵渣问题。为此,在对小麦秸秆(XM)燃烧过程中灰熔融温度(AFT)及其结渣机理的研究基础上,借助X射线衍射仪(XRD)、共聚焦拉曼光谱仪(Raman)、扫描电子显微镜(SEM)等方法,结合FactSage热力学软件计算氧化性气氛下随鸡粪(JF)的加入小麦秸秆灰熔融过程中矿物质迁移转化行为。研究结果表明:当添加的鸡粪质量分数>15%时,变形温度(DT)>1000℃,满足流化床运行要求。随着鸡粪质量分数的增加,镁黄长石(Ca_(2)MgSi_(2)O_(7))和镁硅钙石(Ca3MgSi_(2)O_(8))等高熔点(MP)长石类矿物质的生成是XM四种特征温度升高的主要原因。从硅酸盐角度分析,鸡粪的加入促使灰样中桥氧键以及硅酸盐聚合度增加,导致混合灰样的AFT升高。根据灰渣的组成和灰熔融特性,并借助SEM对灰渣表面微观形貌进行观察,发现随着鸡粪质量分数的增加,950℃时灰渣表面由紧密光滑变为疏松多孔且粗糙,极大程度缓解了生物质结渣、烧结等问题。结合热力学软件FactSage计算不同温度下矿物质组成和液相质量分数,发现加入鸡粪提高了液相总质量分数。高熔点矿物质发生低温共熔现象,导致FT升高范围小于DT。鉴于以上结论,通过实验和热力学计算对生物质燃烧过程中的AFT变化和结渣机理进行研究,以期为生物质能源的规模化应用提供数据支持。Under the carbon neutral and carbon peak background,biomass can be used as an alternative clean energy source for coal resources,its efficient utilization has become a hot issue in current research.Biomass usually has a high content of alkali metals and alkaline earth metals,which can easily cause slagging and slag blocking during the combustion process.Therefore,in this study,the ash fusion temperature(AFT)and its slagging mechanism during biomass combustion were investigated,using experimental characterization methods such as X-ray diffraction(XRD),confocal Raman spectroscopy(Raman),scanning electron microscopy(SEM),and thermodynamic software FactSage,the migration and transformation behavior of minerals during the melting process of XM ash with the addition of chicken manure in an oxidizing atmosphere was modeled.The results showed that when more than 15%JF was added,the deformation temperature(DT)was more than 1000℃,which met the requirements of fluidized bed operation.With the increase of JF content,the formation of high melting point(MP)feldspar-like minerals such as akermanite(Ca_(2)MgSi_(2)O_(7))and merwinite(Ca3MgSi_(2)O_(8))was the main reason for the increase of four characteristic temperatures of XM.From the perspective of silicate,the addition of JF increases the bridging oxygen bonds and the degree of polymerization of silicate in the ash sample,increasing the AFT of the mixed ash sample.According to the slag composition and ash melting characteristics,and by observing the microscopic morphology of the ash surface with the aid of SEM,with the increase of JF content,the ash surface changed from compact and smooth to porous and rough at 950℃,greatly alleviating the problems of biomass slagging and sintering.Using the thermodynamic software FactSage to calculate the mineral composition and liquid con-tent at different temperatures,it was found that adding JF increased the total liquid phase content.The phenomenon of low temperature co-melting occured in high MP minerals resulting in a smaller incre

关 键 词：生物质 鸡粪 燃烧 灰熔融特性 结渣机理 

分 类 号：TK62[动力工程及工程热物理—生物能]