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Asphaltene-based carbon fiber, needle coke, and porous carbon nanosheets were synthesized using the extracted asphaltene from coal-heavy oil co-refining residue. Asphaltene with high average molecular weight and aromaticity is considered proper to be polymerized or crosslinked, and is a high-performing precursor to synthesize carbon materials. It can be transferred into pitch after pyrocondensation polymerization; the resultant asphaltenebased carbon fiber with a tensile strength of 0.92 GPa was obtained via spinning, preoxidization, and carbonization. While high graphitized needle coke was formed when asphaltene underwent thermal polycondensation, delayed coking, and carbonization, it provided a facile route to produce needle coke from asphaltene. A porous carbon nanosheet with a high surface area of 1717 m 2 /g and pore volume of 0.94 cm 3 /g was synthesized using asphaltene as carbon precursor, melamine as nitrogen resource, and molten salt as template; the porous carbon nanosheet showed high CO 2 adsorption amount and outstanding adsorption selectivity for CO 2 -N 2 and CO 2 -CH 4 . It indicated that asphaltene was an excellent precursor to prepare functional carbon materials for its adjustable molecular weight distribution, high aromaticity, controllable thermal condensation, and easy graphitization. It provided an effective strategy to tailor solid residue from coal and heavy oil co-refining and developed directional conversion or utilization of asphaltene.

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A high yield spinnable pitch for isotropic pitch-based carbon fiber was successfully prepared by air oxidation polycondensation of asphaltene with styrene-ethylene-butylene-styrene. The effects of reaction temperature and time, added styreneethylene-butylene-styrene amount on the composition and spinning properties of resultant pitches were investigated. The resultant pitch with a concentrated molecular weight distribution of 300-700 Da was prepared at 340°C for 3 h under air blowing with 5% styrene-ethylene-butylene-styrene, moreover, its more alkyl structure (mainly methylene), lower apparent viscosity above the softening point, and good spinnability endowed the resultant pitches more prone to oxygen crosslinking during the stabilization process. The average tensile strength of resultant pitch-based carbon fibers was over 800 MPa after carbonization at 1000°C for 10 min. It provided a simple method to adjust the spinnable pitch for pitch-based carbon fiber preparation.

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