生物质气化站玉米芯飞灰的特性及其综合利用  

Ash properties and integrated uses of corncob fly ash from biomass gasification station

作　　者：姚锡文[1] 许开立[1] 

机构地区：[1]东北大学资源与土木工程学院,沈阳110819

出　　处：《农业工程学报》2015年第20期218-224,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：农业部农村能源综合建设项目(2015-36);辽宁省自然科学基金资助项目(2013020137)

摘　　要：作为玉米生产加工过程的农业废弃物,玉米芯的产量巨大,生物质气化工业利用玉米芯原料制备生物质燃气的过程中将产生大量的玉米芯灰。为了全面认识这些废弃玉米芯灰的灰特性及可能的应用,通过激光粒度分析、X射线荧光(X-ray fluorescence,XRF)、X射线衍射(X-ray diffraction,XRD)、热重和差热分析(thermal gravimetric and differential thermal analysis,TG-DTA)、扫描电镜(scanning electron microscopy,SEM)、能谱分析(energy dispersive X-ray,EDX)等方法对其进行深入研究。结果表明:玉米芯灰的粒度较小且分布不均,平均粒径为12.96μm;灰的元素组成中K和Si所占的比重最大;富含K、Ca、S和Cl等元素使玉米芯灰可用作土壤改良剂,而且灰中大量的Si O2和Al2O3使其可以用来制备抗压强度较高的水泥混凝土;灰中存在多种含钾元素的KHCO3、KAl Si O4、KAl Si2O6、KCl和K2SO4等结晶相矿物成分;灰粒的形状极不规则,树枝状的团聚灰渣具有丰富的空隙,易逐级吸附小颗粒,灰粒表面存在大量弱粘结的絮状物,断面多为孔状结构;熔融灰粒表面存在富钾现象,且多以KCl形式存在;飞灰的热解具有分段机制,加热到1 200℃时,其总失重和最大失重速率均随着氧气浓度的升高而增加;氮气中620℃的吸热峰是由KCl熔融吸热所致,而有氧气氛中在630℃处的放热峰则是未燃尽的残碳继续燃烧或有机物分解放热所致。Globally, biomass resources regarded as a green renewable energy has the potential of being more important in the future, which attract worldwide attention regarding their renewable nature, carbon dioxide-neutral characteristics, and world-wide availability. Consequently, many countries are putting great emphasis on the exploration of bio-energy, and the techniques used are various such as combustion, gasification, pyrolysis, hydrogen production, and so on. As a by-product generated from the processing of corn, the production of corncob（CC） is rather abundant, and reaches up to 3.87 million tons per year in China. The biomass gasification industries make use of CC residues as raw materials for producing biomass fuel gas. However, the gasification generates tons of corncob ash（CCA） everyday, which is requiring daily disposal properly. Herein this study is focused on the preliminary properties of waste CCA to analyze how it could be transformed into eco-friendly value added products. For a broad awareness of properties and possible utilizations of these waste CCA, some techniques were used such as laser particle size analyzer（LPSA）, X-ray fluorescence（XRF）, X-ray diffraction（XRD）, thermal gravimetric and differential thermal analysis（TG-DTA）, scanning electron microscopy（SEM） coupled with energy dispersive X-ray（EDX）. The results showed that the granularity distribution of CCA powders was very homogeneous, and the particle size analysis showed a mean diameter of 12.96 μm and a medium diameter of 10.23 μm. The elemental composition revealed that potassium and silicon were the most abundant elements. Being rich in potassium, calcium, sulfates and chlorine made CCA suitable for using as soil amendment and the high content of combined SiO 2 and Al2O3 made it possible to be used a pozzolan in blended cement concrete. The XRD spectrogram indicated the presence of several crystalline phases in CCA. Many crystalline phase minerals containing potassium in the ash present in forms of KHCO3,

关 键 词：生物质 气化 碱金属 玉米芯灰 灰特性 结渣 

分 类 号：TK6[动力工程及工程热物理—生物能]