Catalytic hydroconversion of extraction portion from coal tar residue to clean liquid fuel over a Ni based ZSM-5/PC derived from coal gasification fine slag

The efficient utilization of industrial solid waste not only reduces environmental pollution, but also increases economic benefit. In this study, a Ni-based ZSM-5 zeolite/porous carbon composite (Ni10%@ZSM-5/PC) was prepared from coal gasification fine slag and used for upgrading petroleum ether-extractable portion (PEEP) from coal tar residue. PEEP yield is 70.1%. According to the detection with a gas chromatograph/mass spectrometer, PEEP mainly contains O-containing organic compounds (37.0%), arenes (32.0%), chain alkanes (27.2%), alkenes (1.8%), N-containing organic compounds (0.8%), and S-containing organic compounds (1.0%). The catalytic hydroconversion (CHC) of PEEP was carried out at 160 oC for 24 h under 5 MPa initial hydrogen pressure. The resulting refined oil (PEEPC) is mainly composed of chain alkanes (45.1%), cyclanes (33.7%), hydroarenes (16.9%), and alkenes (4.4%). Hierarchical porous zeolite-PC with strong B acid sites and uniformly dispersed Ni nanoparticles (NNPs) in Ni10%@ZSM-5/PC play important roles in aromatic ring (AR) hydrogenation and heteroatom removal. According to the CHC of benzyloxybenzene (BOB) with >C-O- bridged bonds and ARs, it was speculated that Ni10%@ZSM-5/PC can activate H2 to diatomic active hydrogen (H···H) with NNPs and release proton hydrogen (H+) from HZSM-5/PC, further promoting >C-O- cleavage and AR hydrogenation.