Improvement of ash flow properties of low-rank coal for entrained flow gasifier
Improvement of ash flow properties of low-rank coal for entrained flow gasifier
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DOI：
10.1016/j.fuel.2013.12.001
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发表时间：
2014-03
期刊：
影响因子：
7.4
通讯作者：
Lingxue Kong;J. Bai;Zongqing Bai;Zhenxing Guo;W. Li
中科院分区：
文献类型：
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作者：
Lingxue Kong;J. Bai;Zongqing Bai;Zhenxing Guo;W. Li
为了满足气流床气化炉的排渣要求，采用添加耐火材料高岭土和高SiO2、Al 2 O3含量的煤来改善低阶煤的熔融温度和粘度等灰流特性。FACTsage软件包用于预测作为温度的函数的固相和矿物的比例。X射线衍射（XRD）分析进行，以确定在灰中的主要晶相。结果表明，添加高岭石后灰熔融温度的变化规律与添加高SiO2和Al 2 O3含量煤后的变化规律相似。随着高岭石添加量的增加和高SiO2、Al 2 O3含量煤的增加，煤的热稳定性先降低，然后降低，达到最小值后又升高。灰成分在伪三元相图中的位置和灰中矿物的变化可以用来解释添加高岭石或高SiO2和Al 2 O3含量煤的低阶煤的灰熔融温度的变化。高SiO2和Al 2 O3含量的高岭石和煤的加入量越大，炉渣的粘度也越大。SiO2-Al 2 O3-“FeO”-CaO-MgO系统对温度漂移的敏感性随高岭石添加量和煤中SiO2、Al 2 O3含量的增加而降低，而随高岭石添加量和煤中SiO2、Al 2 O3含量的增加而降低。同时，配煤方式具有较大的出钢温度范围，对改善气流床气化炉灰流特性效果较好。
In order to meet the demand of slagging for entrained flow gasifier, addition of refractory agent kaolinite and coal with high SiO2and Al2O3contents was applied to improve ash flow properties of low-rank coal including fusion temperature and viscosity. The FACTsage software package was used to predict proportion of solid phase and minerals as a function of temperature. X-ray diffraction (XRD) analysis was carried out to identify the major crystalline phases in ash. The results show that the variation of ash fusion temperatures (AFTs) with addition of kaolinite is similar to that with addition of coal with high SiO2and Al2O3contents. It first decreases with increasing amount of kaolinite addition and coal with high SiO2and Al2O3contents, and then decreases and reaches a minimum value before increasing again. The location of ash composition in pseudoternary phase diagram and mineral changes in ash can be used to explain the variation of ash fusion temperatures of low-rank coal with addition of kaolinite or coal with high SiO2and Al2O3contents. Viscosity of slag also increases with increasing additions of kaolinite and coal with high SiO2and Al2O3contents. The sensitivity of slag viscosity to temperature excursion decreases with increasing of kaolinite addition and coal with high SiO2and Al2O3contents, because the sensitivity of the SiO2–Al2O3–‘FeO’–CaO–MgO system to temperature excursions decreases with increasing kaolinite addition and coal with high SiO2and Al2O3contents. Meanwhile, coal blending method has a larger tapping temperature range and shows a better effect on improving ash flow properties for entrained flow gasifier.