Liquefaction of Hongliulin coal asphaltenes and conversion of oxygenic structure

Abstract

Based on the multistage liquefaction process, asphaltene was prepared from Hongliulin coal and deeply liquefied with Ni-Co-Mo, Co-Mo, and Fe2O3 catalysts. The yields of each component were obtained. Ultimate analysis, FT-IR and XPS was used to investigate the conversion of oxygenic structure. The results showed that the ability to catalyze asphaltene conversion was ranked as Ni-Co-Mo > Co-Mo > Fe2O3 in the range of 440–480 °C. The highest oil yield was 44.31% at 470 °C with Ni-Co-Mo catalyst. Ni-Co-Mo catalyst could effectively increase the H/C ratio and reduce the oxygen content of asphaltene, which had a strong correlation with the trend of oil yield. The main forms organic oxygen in remaining asphaltene after liquefaction were C = O, C-O and COO and the contents decreased sequentially. Ni-Co-Mo could catalyze the cleavage of C = O significantly to form a large amount of C-O and improve the oil yield after 460 °C. The C-O content was about 34% in remaining asphaltene, which was mainly a relatively stable aromatic ether structure and was not susceptible to hydrocracking reactions.