Coking behavior and mechanism of direct coal liquefaction residue in coking of coal blending
Coking behavior and mechanism of direct coal liquefaction residue in coking of coal blending
复制标题
煤直接液化残渣在配煤炼焦中的结焦行为及机理
DOI：
10.1016/j.fuel.2020.118488
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发表时间：
2020-11-15
期刊：
影响因子：
7.4
通讯作者：
Gao, Jinsheng
中科院分区：
文献类型：
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作者：
Chen, Zhihui;Wu, Youqing;Gao, Jinsheng
本研究首次将煤直接液化残渣（DCLR）与五种炼焦煤直接混合。研究了 DCLR 添加对焦炭质量的影响。还阐明了 DCLR 作为配煤粘合剂的结焦机理。结果表明，在配煤中添加5%和10%的DCLR，可分别减少高粘结性煤8%和13%，且不会造成冷机械强度的明显损害。与JM（焦煤）和FM（肥煤）沥青质相比，DCLR沥青质表现出明显的差异，其含有较高比例的芳香族C=C和脂肪族-CH2-官能团，可以间接增强配煤的粘结性，提高焦炭的冷机械强度，导致M-13的冷机械强度从90.31%提高到96.77%。 DCLR参与焦化的过程可以概括为两个阶段。首先，DCLR可以在煤热解初期（350-380℃）充分润湿煤颗粒表面，抑制煤颗粒中气体逸出，从而产生较高的内压。其次，在煤热解的关键阶段（380-450℃），内部气体突破化质层，将DCLR产生的粘性化质挤入煤颗粒之间的孔洞中，产生优质焦炭。
Direct coal liquefaction residue (DCLR) was directly blended with five coke-making coals for the first time in this study. The effect of DCLR addition on coke quality was investigated. The coking mechanism of DCLR as a binder in blending coals was also elucidated. Results showed that 5% and 10% DCLR addition to blending coal could reduce 8% and 13% high caking property coals respectively without causing any great impairment in cold mechanical strength. Compared with JM (coking coal) and FM (fat coal) asphaltenes, DCLR asphaltene exhibited obvious differences as it contained higher percentages of aromatic C=C and aliphatic -CH2- functional groups which could indirectly enhance the caking property of blending coal and improve the cold mechanical strength of coke resulting in cold mechanical strength M-13 increasing from 90.31% to 96.77%.The roles of DCLR participating in coking can be summarized in two stages. Firstly, DCLR can fully moisten the surface of coal particles in the early stage of coal pyrolysis (350-380 degrees C) and suppress the gas escaping from coal particles, resulting in a higher internal pressure. Secondly, internal gas breaks through the metaplast layer and squeezes the sticky metaplast produced by DCLR into holes between coal particles in the key stage of coal pyrolysis (380-450 degrees C), leading to high quality coke.