准东高钠煤热解过程中钠的迁移特性实验研究

针对新疆准东煤田高钠煤(简称准东高钠煤)在发电锅炉燃烧时遇到结渣黏污严重的问题,基于立式管式炉热解,利用电感耦合等离子体-原子发射光谱(ICP-AES)、X射线衍射(XRD)以及扫描电镜-能谱(SEM-EDX)等检测手段,分析了准东高钠煤在不同热解温度下碱金属钠的析出特性、赋存形态以及热解半焦的微观形貌.利用Fact sage 6.1化学热力学平衡计算软件分析了碱金属的析出形式.结果表明,准东高钠煤中的碱金属钠在热解过程中有部分析出,开始的析出温度为600 ℃,当热解温度达900 ℃时,碱金属钠的析出率为40.2%;碱金属钠在热解过程中主要以NaCl的形式析出;热解温度低于900 ℃时,没有熔融态物质生成.

Experimental study on alkali metal transformation during high-sodium Zhundong coal pyrolysis

The alkali metal transformation during high-sodium Zhundong coal pyrolysis was investigated in a vertical tubular furnace reactor. The release characteristics, modes of occurrence of Na, the microstructure of char samples after pyrolysis at different temperatures were examined by using inductive coupled plasma equipped with atomic emission spectrometer(ICP-AES), X-ray diffractometry (XRD) and scanning electron microscopy with an energy dispersive X-ray spectrometer(SEM-EDX), respectively. Meanwhile, the release forms of alkali metal from coal were simulated by Fact sage 6.1. The results show that a part of sodium in high-sodium coal is released during pyrolysis, starting to release at 600 ℃ and reaching to 40.2% of release at 900 ℃. It is concluded that Na in the coal is released as NaCl, and no molten matter is found when the pyrolysis temperature is below 900 ℃.