根据褐煤含水量高的特点,研究了水为溶剂下胜利褐煤的加氢液化行为,并与传统的四氢萘(THN)溶剂进行了比较。在380℃、THN为溶剂和H2气氛条件下,煤的液化转化率达到85.3%,其中油气产率和沥青质产率分别为73.2%和12.1%,液化过程中热解产生的自由基碎片是通过供氢溶剂获得活性氢,而非从气相的氢气中直接获得。相对于H2和N2气氛,在CO气氛下以水为溶剂进行的煤液化实验和胜利褐煤表现出优良的液化性能,液化转化率达到70.2%,其中油气产率58.1%,沥青质产率12.1%。在CO/H2O系统中,发生的水煤气变换反应(WGSR)能产生高活性氢,该活泼氢能与煤热解产生的自由基结合生成稳定的液化产物,从而提高了液化的转化率。实验结果表明,在CO气氛下以水为溶剂的液化工艺是可行的,是一种适合含水量较高的褐煤的直接液化工艺。
On the basis of high content of water in brown coal,the hydro-liquefaction behavior of Shengli(SL) coal under different atmospheres using water as solvent was preliminarily studied,comparing with the liquefaction using tetralin(THN) as solvent.In 380 ℃,H2/THN system,the conversion of SL coal gets to 85.3% with 73.2% oil+gas yield and 12.1% asphaltene yield.The active H stabbing residuals which come from the pyrolysis of the coal mainly comes from the hydrogen donor solvent,not directly from H2.In the liquefaction tests with water as solvent,the conversion was higher in CO atmosphere than that in H2 or N2 atmospheres,getting to 70.2% with 58.1% oil+gas yield and 12.1% asphaltene yield.In CO/H2O system,the water gas shift reaction(WGSR) produces high active H which can stab the residuals in order to improve the liquefaction conversion.The results indicate that the liquefaction process in CO/H2O is feasible for brown coal with high content of water.