Abstract The impetus for clean energy utilization has increased acceptance of biomass as a co-fired fuel with coal, since it reduces carbon emissions. This work utilized time-resolved online LIBS measurement to investigate the release of potassium from oxyfuel co-combustion of fuels. A coal-biomass blended particle consisting of 20% biomass (energy basis) is set as a reference fuel, and its results are compared with native biomass and coal particles. As expected, the potassium release rate was highest with 100% biomass and decreased with reducing biomass content in the blend. Therefore, there are trade-offs associated with potassium-related deposition, fouling and corrosion of a boiler’s heat transfer surfaces when biomass and coal are co-fired compared with biomass alone. Analyses of particle size and surface temperature changes suggest that the evolution of potassium in the gas phase can be characterized by temperature evolution. The online measurement for a 20% blend indicates that about 80% of the releasable potassium is volatilized, mainly during the char combustion stage. The release kinetics model developed obeys an Arrhenius expression. The activation energy reported for a 20% fuel blend was 161.9 kJmol−1 K, and was much lower than that of 100% biomass, but higher than that of 100% coal.

中文翻译：

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使用激光诱导击穿光谱法测定生物质和煤富氧混合燃烧过程中的碱释放

摘要 由于生物质能减少碳排放，清洁能源利用的推动力使得人们越来越多地接受生物质作为与煤共燃的燃料。这项工作利用时间分辨在线 LIBS 测量来研究燃料混合燃烧中钾的释放。将含有 20% 生物质（能量基础）的煤生物质混合颗粒作为参考燃料，并将其结果与天然生物质和煤颗粒进行比较。正如预期的那样，100% 生物质的钾释放率最高，并随着混合物中生物质含量的降低而降低。因此，与单独使用生物质相比，当生物质和煤共同燃烧时，存在与钾相关的沉积、结垢和锅炉传热表面腐蚀相关的权衡。对颗粒大小和表面温度变化的分析表明，气相中钾的析出可以通过温度演化来表征。20% 混合物的在线测量表明，大约 80% 的可释放钾被挥发，主要是在炭燃烧阶段。开发的释放动力学模型遵循 Arrhenius 表达式。报告的 20% 燃料混合物的活化能为 161.9 kJmol-1 K，远低于 100% 生物质的活化能，但高于 100% 煤的活化能。