Comparison of catalytic hydroliquefaction of Xiaolongtan lignite over FeS, FeS+S and SO42-/ZrO2

The catalytic hydroliquefaction of Xiaolongtan lignite (XL, a Chinese lignite) was investigated in a batch autoclave. The effects of reaction temperature, time and initial H2 pressure on the yields of gaseous and extractable portions (GEPs) were discussed. The catalytic activity of FeS+S was compared with that of FeS and SO42-/ZrO2, respectively. The results show that FeS+S is more active for XL hydroliquefaction than the other two catalysts and affords the highest gas and oil (G & O) yields in the three catalysts. The highest total yield of GEPs from XL hydroliquefaction gets to 90.0%, while total yield of G & O is 61.1% at 420 °C for 30 min over FeS+S. The assistant catalysis of the added sulfur was discussed. The structural features of asphaltenes and preasphaltenes were examined by elemental and FTIR analyses.