玉米芯生物质灰的物理化学特性

Physicochemical Characteristics of Corn Cob Biomass Ash

采用X射线荧光光谱、X射线衍射、扫描电镜、粒度分析等实验方法研究了不同灰化温度(600℃和815℃)下制得的玉米芯灰的理化特性.利用马弗炉灼烧实验考察了灰化温度和保温时间对灰分量的影响,并通过扫描电镜-能谱联用技术对生物质气化站现场采集的玉米芯灰的灰成分和灰形态进行了分析.研究发现,灰化温度对灰粒度、灰分量、灰成分、灰形态和物相变化均有明显影响,但对积灰结渣特性影响不明显;灰的主要组成元素为钾和氯,玉米芯热解气化排放钾的主要形式是氯化钾;灰表面的形态各异,600℃灰化时形成絮状的大颗粒,815℃时灰表面发生软化熔融,絮状物减少.该研究可为生物质燃料经热化学转化后的燃气净化及生物质灰的综合利用提供指导.

The physicochemical characteristics of corn cob ash obtained at different ashing temperatures （600 ℃ and 815 ℃ ） were studied with X-ray fluorescence spectrometry, X-ray diffraction, scanning electronic microscopy and experiment was adopted to study the influence of grading analysis. Muffle furnace burning ashing temperature and holding time on ash content. The ash composition and morphology of the fly ash samples collected from biomass gasification station were analyzed by using scanning electron microscopy （SEM） and energy disperse X-ray microanalysis （EDX）. The results indicated that ashing temperature has a remarkable effect on the ash granularity, content, composition, morphology and phase composition, but has no obvious effects on the fouling and slagging characteristics. The main component elements of ash are potassium and chlorine, which means that the major existent form of potassium is potassium chloride in the pyrolysis and gasification process of corn cob. The morphology of ash surface is in different shapes. Flocculent large particles were formed at the ashing temperature of 600 ℃, while the ash surface happens to soften and fuse, and the flocculent particles decreases at 815 ℃. Above research results can provide guidance not only for the purification of gas obtained from the thermal chemical conversion of biomass fuel, but also for the comprehensive utilization of biomass ash.