Release and transformation of chlorine and potassium during pyrolysis of KCl doped biomass
Release and transformation of chlorine and potassium during pyrolysis of KCl doped biomass
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DOI：
10.1016/j.fuel.2017.02.046
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发表时间：
2017-06
期刊：
影响因子：
7.4
通讯作者：
Yang Wang;Hao Wu;Z. Sárossy;C. Dong;P. Glarborg
中科院分区：
文献类型：
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作者：
Yang Wang;Hao Wu;Z. Sárossy;C. Dong;P. Glarborg
研究了生物质热解过程中CH3Cl的形成以及氯和钾的转化。模型生物质化合物（纤维素、木聚糖、木质素和果胶）和掺杂 KCl 的松木在 TGA 中以不同的加热速率（10–1000 °C/min）、温度（300–850 °C）和 KCl 含量（0–5 wt%）进行热解。收集挥发物并通过 GC-MS 分析 CH3Cl 浓度。通过ICP-OES分析固体残余物的总含量和水溶性K和Cl的含量。在 KCl 掺杂的松木、木质素和果胶样品的热解过程中形成了大量的 CH3Cl，相当于燃料氯的 20-50%，这表明这些生物质通过甲氧基对 KCl 具有甲基化能力。木质素和松木在掺杂高达约2%的KCl时可以提供甲氧基进行反应，而果胶的能力甚至更大。在所有样品的固体残留物中都发现了有机钾，进一步支持了 KCl 与生物质中有机基质之间发生反应。保温温度为 500 °C 时，加热速率从 10 °C/min 增加到 500 °C/min 显着降低了 KCl 掺杂木材/木质素/果胶中 CH3Cl 的产率，而在 1000 °C/min 时没有观察到进一步的降低效果。对于 500 °C/min 的加热速率，保温温度从 300 °C 增加到 850 °C 导致 CH3Cl 产率下降。
The formation of CH3Cl and the transformation of chlorine and potassium during pyrolysis of biomass were investigated. Model biomass compounds (cellulose, xylan, lignin and pectin) and pine wood doped with KCl were pyrolysed in a TGA at different heating rates (10–1000 °C/min), temperatures (300–850 °C), and KCl contents (0–5 wt%). The volatiles were collected and analyzed for CH3Cl concentration by GC–MS. The solid residue was analyzed by ICP-OES for the contents of total and water soluble K and Cl. Considerable amounts of CH3Cl, corresponding to 20–50% of the fuel chlorine, were formed in pyrolysis of KCl doped pine wood, lignin and pectin samples, suggesting a methylation ability of these biomass on KCl by their methoxyl groups. Lignin and pine wood could supply methoxyl groups for reaction with as much as about 2% KCl doping, and pectin had an even greater capacity. Organic K was found in the solid residue of all samples, further supporting the occurrence of reactions between KCl and the organic matrix in biomass. With a holding temperature of 500 °C, an increase of heating rate from 10 °C/min to 500 °C/min significantly reduced the yield of CH3Cl from KCl doped wood/lignin/pectin, while no further reduction effect was observed at 1000 °C/min. For a heating rate of 500 °C/min, an increase of holding temperature from 300 °C to 850 °C caused a decreased yield of CH3Cl.