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Five organic solvents, N-methyl-2-pyrrolidone (NMP), cyclohexanone (CYC), N,N-dimethyl­formamide (DMF), acetonitrile (ACN), and toluene (TOL) were used to treat Shenhua direct coal liquefaction residue (DCLR) by swelling processes. The treated residues were characterized by swelling degree (Q), SEM, FTIR, TG-DTG, and Py-GC/MS methods. The effect of swelling treatment on the swelling properties, surface morphology, functional group distribution, and pyrolysis performance of the residues was investigated. Swelling results showed that the swelling effect with different solvents on each residue was different and that the swelling degree of the residue treated by NMP was high, 2.4. Swelling treatment could significantly change the surface morphology and pore structure of DCLR, resulting in the increase of pores in the residue. FTIR spectra proposed that swelling treatment could effectively break the hydrogen bonds in residue and change the abundance of oxygen-containing functional groups. TG-DTG profiles demonstrated that the swelling procedure could increase the weight loss and pyrolysis rate of the residue, and the pyrolysis activation energy in high-temperature region (≥360 °C) was obviously reduced, while the energy in the low-temperature region (120–360 °C) was increased. Py-GC/MS proposed that the swelling pretreatment could change the pyrolysis product distribution of the residue, with the species of the products decreased, and that ketones and arenes compounds were the main products.

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Modified Ni-Al 2 O 3 catalysts with Ca, Co, and Ce species as promoters were prepared by the combustion method, and the structure, morphology, reduction characteristic, and CO 2 –CH 4 reforming of the catalysts were discussed by X-ray diffraction (XRD), H 2 -temperature-programmed reduction (H 2 -TPR), energy-dispersive X-ray (EDX) mapping, NH 3 -temperature-programmed desorption (NH 3 -TPD), N 2 adsorption–desorption, thermogravimetric-differential thermal analysis (TG-DTG), and temperature-programmed hydrogenation (TPH) methods. The crystal size of Ni on Ca-Ni-Al 2 O 3 was 16.97 nm, and the active component and additive were distributed well in the catalyst. Co-Ni-Al 2 O 3 presented a surface area of 65.70 m 2 ·g –1 and a pore diameter of 161.60 nm. Ce-Ni-Al 2 O 3 showed relatively stable nickel–aluminum spinel (NiAl 2 O 4 ), which could not be easily reduced to the active component Ni. Evaluation results demonstrated that the performance of the catalysts followed the order Co-Ni-Al 2 O 3 > Ca-Ni-Al 2 O 3 > Ni-Al 2 O 3 > Ce-Ni-Al 2 O 3 . Carbon deposition analysis showed that the carbon resistance of Ca-Ni-Al 2 O 3 was poor and graphitic carbon was generated on the catalyst. However, Ce-Ni-Al 2 O 3 showed less carbon deposition, which might have resulted from the lower activity of the catalyst.