LNEG, Estrada do Paço do Lumiar, 22, 1649-032 Lisboa, Portugal.
Waste Manag. 2012 Apr;32(4):769-79. doi: 10.1016/j.wasman.2011.08.021. Epub 2011 Oct 1.
This paper presents the study of the combustion of char residues produced during co-gasification of coal with pine with the aim of characterizing them for their potential use for energy. These residues are generally rich in carbon with the presence of other elements, with particular concern for heavy metals and pollutant precursors, depending on the original fuel used. The evaluation of environmental toxicity of the char residues was performed through application of different leaching tests (EN12457-2, US EPA-1311 TCLP and EA NEN 7371:2004). The results showed that the residues present quite low toxicity for some of pollutants. However, depending on the fuel used, possible presence of other pollutants may bring environmental risks. The utilization of these char residues for energy was in this study evaluated, by burning them as a first step pre-treatment prior to landfilling. The thermo-gravimetric analysis and ash fusibility studies revealed an adequate thermochemical behavior, without presenting any major operational risks. Fluidized bed combustion was applied to char residues. Above 700°C, very high carbon conversion ratios were obtained and it seemed that the thermal oxidation of char residues was easier than that of the coals. It was found that the char tendency for releasing SO(2) during its oxidation was lower than for the parent coal, while for NO(X) emissions, the trend was observed to increase NO(X) formation. However, for both pollutants the same control techniques might be applied during char combustion, as for coal. Furthermore, the leachability of ashes resulting from the combustion of char residues appeared to be lower than those produced from direct coal combustion.
本文研究了煤与松木共气化过程中产生的炭残馀物的燃烧特性，旨在对其进行特性分析，以确定其在能源方面的潜在用途。这些残渣通常富含碳，同时存在其他元素，特别是重金属和污染物前体，这取决于所使用的原始燃料。通过应用不同的浸出试验（EN12457-2、US EPA-1311TCLP 和 EA NEN 7371:2004）对炭残馀物的环境毒性进行了评估。结果表明，对于某些污染物，残渣的毒性相当低。然而，根据所使用的燃料，可能存在其他污染物会带来环境风险。在这项研究中，这些炭残馀物被用作能源进行了评估，首先在进行土地填埋之前进行燃烧预处理。热重分析和灰熔融性研究表明，其具有适当的热化学行为，不存在任何重大操作风险。流化床燃烧被应用于炭残馀物。在 700°C 以上，获得了非常高的碳转化率，而且似乎炭残馀物的热氧化比煤更容易。发现炭残馀物在氧化过程中释放 SO(2)的趋势比母体煤低，而对于 NO(X)排放，观察到形成 NO(X)的趋势增加。然而，对于这两种污染物，在炭燃烧期间可以应用相同的控制技术，就像煤一样。此外，炭残馀物燃烧产生的灰分的浸出率似乎低于直接燃煤产生的灰分。
