【作者】 孔令学； 白进； 李文； 李怀柱； 白宗庆；

【Author】 KONG Lingxue;BAI Jin;LI Wen;LI Huaizhu;BAI Zongqing;State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences;

【机构】 中国科学院山西煤炭化学研究所,煤转化国家重点实验室；

【摘要】 由于原料良好的灵活性和高的效率,气流床气化技术已成为煤气化过程首选的气化工艺。为了增加气流床气化可用煤种的范围,石灰石常被用来作为助熔剂添加到原料煤中获得合适煤灰熔渣黏温特性的气化原料。实验研究了CaO对不同硅铝比（S/A）煤灰熔渣黏温特性的影响,并利用FactSage6.4计算了煤灰熔渣中固相含量和液相组成的改变。结果表明:当温度高于临界黏度温度（TCV）时,CaO的增加导致了煤灰熔渣中Si-O-Si的断裂和固相含量的降低,使得煤灰熔渣的黏度随着CaO含量的增加不断降低。TCV随着CaO含量的增加不断降低,但当CaO含量超过一定值时,TCV随着CaO含量的增加快速升高。另外,随着CaO含量的增加,煤灰熔渣由结晶渣逐渐转变为玻璃体渣,而在CaO含量较高时,煤灰熔渣又转化为结晶渣或塑性渣。FactSage计算表明TCV和煤灰熔渣类型随CaO含量的改变与熔渣中固相生成速率（r）密切相关。最大固相生成速率对应的温度(T_max)与TCV具有良好的线性关系（TCV=0.98Tmax+17.33）（图1）;当r大于0.25wt%/oC,煤灰熔渣为结晶渣或塑性渣（图2）。这些关系提供了一个有效的方法用于预测CaO含量对TCV及熔渣类型的影响。更多还原

【Abstract】 Entrained flow gasification is becoming the most promising gasification process due to its good flexibility of fuel feedstock and high efficiency. To increase the range of coals that can be processed in entrained flow slagging gasifiers, a common practice is to blend the feedstock with limestone to produce a feed with appropriate slag viscosity behavior. The effect of CaO on the viscositytemperature behavior of slag from coal with different silica/alumina ratio（S/A） was studied for using flux. FactS age 6.4 was used to calculate the amount of solid phase and compositional change of liquid phase in molten slag. The results shows that when temperature is above temperature of critical viscosity（TCV）, slag viscosity decreases with increasing CaO content due to breakage of Si-O-Si and decrease of amount of solid phase by Ca O. TCV also decreases with increasing Ca O content, while it sharply increases at higher Ca O content. Furthermore, slag changes from a plastic/crystalline slag into a glassy one with increasing CaO content, and a plastic/crystalline slag is shown at higher CaO content again. FactS age calculation reveals that TCV and type of slag are closely related with the rate of solid phase formation（r）. There is an apparent linear correlation and excellent agreement between TCV and temperature of maximum rate of solid phase formation(T_max)(TCV=0.98T_max+17.33). When r is over 0.25 wt%/oC, slag behaves as a plastic/crystaline slag. These correlations provide a useful method to predict the effect of Ca O on TCV and type of slag.更多还原