The release of water-bound and organic sodium from Loy Yang coal during the combustion of single particles in a flat flame
The release of water-bound and organic sodium from Loy Yang coal during the combustion of single particles in a flat flame
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DOI：
10.1016/j.combustflame.2010.10.024
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发表时间：
2011-06
影响因子：
4.4
通讯作者：
P. V. Eyk;P. Ashman;Z. Alwahabi;G. Nathan
中科院分区：
文献类型：
--
作者：
P. V. Eyk;P. Ashman;Z. Alwahabi;G. Nathan
采用定量平面激光诱导荧光（LIF）技术测量了在平坦火焰环境中燃烧的褐煤颗粒羽流中原子钠的浓度。采用机械/热表达法对一种原煤（LY-ROM）和两种Loy Yang褐煤（MTE1和MTE2）进行了处理，去除了一部分固有水分和伴随的溶解盐。通过应用化学平衡模型，在火焰中的适当位置，根据测量的原子钠浓度谱估计钠的总释放量。对于LY-ROM、MTE1和MTE2，脱挥发后钠释放总量占煤中初始钠的比例分别为80.9±19.5%、87.9±19.0%和93.0±28.0%。利用这些数据，可以推断出大约67%的水合钠和约100%的有机结合钠在脱挥发后被释放。此外，在目前的实验中，高达60%的总钠是在焦炭燃烧后，灰在扁平火焰中保留的时期释放的。提出了一种机制来解释这种观察，其中Na2O在灰与周围的水蒸气在高温下反应。
The concentration of atomic sodium in the plume of single brown-coal particles burning in a flat flame environment is measured using quantitative planar laser-induced fluorescence (LIF). A run-of-mine Loy Yang brown coal (LY-ROM) and two Loy Yang brown coals (MTE1 and MTE2) that were processed using Mechanical/Thermal Expression, which removed a fraction of the inherent moisture and concomitant dissolved salts, were investigated. By applying a chemical equilibrium model, at an appropriate location in the flame, the total sodium release is estimated from the measured atomic sodium concentration profile. For LY-ROM, MTE1 and MTE2 the total proportion of sodium release following devolatilisation, as a percentage of the initial sodium in the coals, was 80.9±19.5%, 87.9±19.0% and 93.0±28.0% respectively. Using this data, it is inferred that approximately 67% of water-bound sodium and approximately 100% of the organically-bound sodium is released following devolatilisation. Furthermore, in the present experiments up to 60% of the total sodium is released during the period in which the ash remains within the flat flame, following char combustion. A mechanism is proposed to explain this observation in which Na2O in the ash reacts with ambient water vapour at high temperature.