摘要
根据褐煤含水量高的特点,研究了以水为溶剂,不同气氛条件下小龙潭褐煤的液化行为。结果表明,小龙潭褐煤具有较好的液化活性,在420℃,H2气氛下以四氢萘为溶剂时煤的液化转化率可达到94.5%。煤液化过程中,稳定热解产生的自由基活性氢主要来自于供氢溶剂,而气相H2不具活性,不能直接为液化过程提供活性氢。当以水为溶剂取代四氢萘进行褐煤直接液化时,相对于H2和N2气氛,CO气氛下表现出较好的液化性能。这表明发生了水煤气变换反应并生成了活性氢,该活性氢可以使得煤热解产生的自由基稳定,生成低分子的液化产物,提高了液化转化率。由于在较低的CO初压下反应生成的活性氢数量有限,因而液化转化率不高。实验表明,以水为溶剂在CO气氛下进行褐煤的液化是一种新的褐煤直接液化技术。
The liquefaction properties and mechanism of Xiaolongtan （XLT） lignite were studied. On the basis of high content of water in lignite, the liquefaction behavior of XLT lignite under different atmospheres using water as solvent was preliminarily probed. The results show that XLT lignite has a good liquefaction activity, and its liquefaction conversion gets to 94.5% at 420℃, H2 atmosphere, and tetralin （THN） used as solvent. During coal liquefaction, the active H stabilizing free radicals formed during coal pyrolysis is mainly from hydrogen donor solvent. H2 gas has no hydrogenation activity, and it can not directly provide active H for coal liquefaction. When water is used as solvent instead of THN in liquefaction of XLT lignite, high liquefaction conversion occurs under CO atmosphere compared to H2 or N2 atmosphere. This suggests that the water gas shift reaction produces active H under CO atmosphere. The active H stabilizes the free radicals formed from coal pyrolysis to form lower molecular weight liquefaction products, and therefore, increasing liquefaction conversion. Because of the low primary pressure of CO in the experiment, the active H formed from the water gas Shift reaction is limited. Thus, the liquefaction conversion of XLT lignite is not high when water is used as solvent. But our preliminary study shows that it is a new lignite liquefaction technology using water as solvent under CO atmosphere and has remarkable market value and utilization prospects.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2009年第3期257-261,共5页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(20676001,20776001)
国家高技术研究发展计划(863计划,2006AA05Z314,2007AA06Z113)
安徽省国际科技合作项目(07080703001)
关键词
直接液化
供氢溶剂
CO气氛
褐煤
direct liquefaction
hydrogen donating solvent
CO atmosphere
lignite
