灰化温度对生物质灰特征的影响

Effect of ashing temperature on the characteristics of biomass ash

针对我国在进行生物质灰分分析时采用煤质分析标准的现状,对八种生物质分别在高温(GB T212-2001中规定的温度,820℃)和低温(ASTM E870 82(1998修正)中规定的温度,600℃)下进行了灰化,测定了灰分量,并利用EDX SEM对灰成分和形态进行了分析。结果显示,灰化温度对灰分量、灰成分和灰形态均有明显的影响,因此在生物质灰分性质分析时宜采用低温灰化的方法。

In utilization of biomass, it is very important for an exact determination of ash characteristics. However, there are no specific standards for biomass-ash analysis in China. The standards for coal-ash analysis are usually used to determine the property of ash in biomass. For a better understanding to the effects of different analysis methods on the results, 8 biomasses including wood dust, cornstalk, corn cob, rice shell, soybean stem, cotton stem, bark and leaf, were ashed at low temperature (corresponding to the temperature required in the standard of ASTM/E 870-82, amended in 1998) and at high temperature (corresponding to the temperature required in the standard of GB/T212-2001). The contents of ash were measured and the composition and morphology of the ash were analyzed using EDX-SEM. The results reveal that ashing temperature has a remarkable effect on the ash content, composition and morphology. Thus it is better to use low temperature ashing method for an exact determination of ash property. A proposal that the standards of biomass quality analysis should be established as soon as possible in China is put forward.