Co-carbonization effect of asphaltine and heavy oil in mesophase development

Asphaltine and heavy oil were extracted by the Soxhlet extraction method from the coliquefaction residue of coal and catalytic cracking slurry oil. The asphaltine was carbonized with different proportions of heavy oil to explore the co-carbonization effect for the sake of performance optimization of the mesophase products. Experimental results indicate that the H/C atomic ratio and alkyl group of polymerized samples gradually increase while insoluble content and softening point of polymerized samples gradually decrease as the percentage of heavy oil in the precursor blend increases. With about 20 wt% of heavy oil, a large number of orderly mesophase flow domains with low softening point (similar to 210 A degrees C) can be obtained and the polymerized sample yield reaches the maximum of 76.68 wt%. When the percentages of heavy oil are higher than about 20 wt%, the mesophase is insufficiently developed due to the higher H/C ratio, lower aromaticity, and molecular weight of raw materials. Moreover, when the percentage of heavy oil is about 80 wt%, discrete mesophase microspheres with relatively uniform size (similar to 9 mu m) and good sphericity can be generated. This work indicates that it is indispensable to adjust the ratio of asphaltine to heavy oil for effectively controlling the performance of mesophase.