Flow properties of ash and slag under co-gasification of coal and extract residue of direct coal liquefaction residue
Flow properties of ash and slag under co-gasification of coal and extract residue of direct coal liquefaction residue
复制标题
DOI：
10.1016/j.fuel.2019.116850
复制
发表时间：
2020-03
期刊：
影响因子：
7.4
通讯作者：
Xiaoyang Cao;B. Peng;Lingxue Kong;J. Bai;Zefeng Ge;Huai-zhu Li;Zhen Liu;Ziyang Feng;Dapeng Bi;Zongqing Bai;A. Szlęk;W. Li
中科院分区：
文献类型：
--
作者：
Xiaoyang Cao;B. Peng;Lingxue Kong;J. Bai;Zefeng Ge;Huai-zhu Li;Zhen Liu;Ziyang Feng;Dapeng Bi;Zongqing Bai;A. Szlęk;W. Li
煤直接液化残渣的有效利用是制约煤直接液化效率的瓶颈。ER与煤的共气化是ER大规模利用的一条很有前途的途径。原料的流动特性包括灰熔融性和炉渣粘度是气化过程的重要参数。为了优化ER与煤的共气化，研究了气化条件下ER与煤的灰熔融性和炉渣粘度行为。结果表明，由于ER中钙、铁含量较高，随着ER掺量的增加，共混物的灰熔融温度降低。掺灰中石英和钙长石的含量随掺灰比的增加而降低。随着ER掺量的增加，炉渣的高温粘度也降低。ER中高含量的钙和铁导致Si-O结构的破坏和[AlO 4]5-向[AlO 6]9-的转化，从而降低炉渣的聚合度。此外，当ER掺量增加到25%时，由于冷却过程中钙长石的形成，炉渣呈现结晶渣的行为。对于气流床气化，添加ER可有效降低气化炉操作温度，提高气化效率，避免出渣问题。最佳ER添加量为10- 20%，出钢温度为1258-1575 °C。
Efficient utilization of the extraction residue (ER) of direct coal liquefaction residue is a bottle neck for the efficiency of direct coal liquefaction process. The co-gasification of the ER and coal is a promising way for large-scale utilization of ER. Flow properties of the feedstock including ash fusibility and slag viscosity are important parameters for the gasification process. To optimize co-gasification of the ER and coal, the ash fusibility and slag viscosity behavior of ER and coal under gasification conditions were studied. The results show that the ash fusion temperatures (AFTs) of the blending were lowered with the increasing blending ratio of ER due to the high content of calcium and iron in ER. The content of quartz and anorthite in the blended ashes decreased with the increasing ER blending ratio. The slag viscosities at high temperatures also decreased as the blending ratio of ER increased. The high content of calcium and iron in ER resulted in the decrease in the slag polymerization degree because of the break of Si-O structure and transformation from [AlO4]5−to [AlO6]9−. Besides, the slag presented the behavior of a crystalline slag when the ER blending ratio was increased up to 25% for the formation of anorthite during cooling. For the entrained flow gasification, the ER addition can effectively lower the operation temperature of the gasifiers, improve the gasification efficiency and avoid the slag tapping problems. The optimal ER addition should be in the range of 10–20%, and the corresponding tapping temperature was 1258–1575 °C.