Department of Environmental Engineering, Faculty of Engineering, Democritus University of Thrace, 67100, Xanthi, Greece.
Department of Mineral Resources Engineering, University of Western Macedonia, 50100, Kozani, Greece.
Environ Sci Pollut Res Int. 2022 Jun;29(28):42647-42663. doi: 10.1007/s11356-021-18225-4. Epub 2022 Jan 28.
Biomass combustion generates considerable amounts of ash that are related to slagging/fouling problems in combustors. Numerous indices have been proposed in the literature for the evaluation of slagging/fouling tendencies. This paper is focused on the characterization of various biomass ashes in terms of their slagging/fouling tendency. For this purpose, the chemical composition of ash samples from fourteen solid biofuels (and a lignite sample as a reference) was analyzed by scanning electron microscope, energy-dispersive spectroscopy, ion chromatography and elemental analysis. Modification/normalization of the available ash indices was performed by taking into account not only the chemical composition of the ash but also the Gross Calorific Value of the fuels and the amount of the produced ash. Two versatile tools were developed, a total Ash Quality Index (tAQI) and an Ash Quality Label (AQL), in order to express the information derived from various indices with a single number or letter. The modified indices result in different characterization from the unmodified ones and lead to a more objective/fair evaluation of the slagging/fouling tendency. The comparison of large number of indices of large number of samples is enabled via the tAQI and the AQL. Samples with a tAQL ≤ 1 belong to class 'A' (low slagging/fouling problems) while samples with a tAQL > 6 belong to class 'G' (extremely high tendency to slagging/fouling problems). The tAQI and AQL are a novel concept for the categorization and labeling of solid biofuels regarding their slagging/fouling tendency and could contribute to the waste/biomass residue market for energy proposes.
生物质燃烧会产生大量灰分，这些灰分与燃烧室内的结渣/积灰问题有关。文献中提出了许多指标来评估结渣/积灰的倾向。本文专注于各种生物质灰分的结渣/积灰倾向的特征描述。为此，通过扫描电子显微镜、能谱分析、离子色谱和元素分析对来自 14 种固体生物燃料（以及一种褐煤样本作为参考）的灰分样本的化学成分进行了分析。通过考虑灰分的化学成分、燃料的总热值和产生的灰分的量，对现有的灰分指数进行了修正/归一化。开发了两种通用工具，即总灰分质量指数（tAQI）和灰分质量标签（AQL），以便用单个数字或字母表示来自各种指数的信息。修正后的指数与未修正的指数有不同的特征，从而对结渣/积灰倾向进行更客观/公平的评估。通过 tAQI 和 AQL，可以对大量样本的大量指数进行比较。tAQL≤1 的样本属于 A 类（结渣/积灰问题低），而 tAQL>6 的样本属于 G 类（结渣/积灰问题极高）。tAQI 和 AQL 是一种针对固体生物燃料结渣/积灰倾向的分类和标记的新概念，可用于能源目的的废物/生物质残余物市场。
