Catalytic performance of nickel catalyst dispersed in emulsion for the co-liquefaction of lignite and heavy residue

A kind of nanoemulsion nickel catalyst was prepared for the application of co-liquefaction of lignite and heavy residue. The particle size and microstructures of dispersed phases in emulsion and the sulfurized product were characterized by dynamic light scattering and transmission electron microscope. Catalytic performances of prepared catalysts at different dosage were investigated and the microscopic features of solid residues with catalyst or not were compared. Experimental results showed the optimization mixing speed for emulsion nickel catalyst preparation was 2000 r/min, with an average diameter of 180 nm, and the active phases of prepared catalyst after sulfurization was Ni3S2. The emulsion nickel catalyst displayed a favorable catalytic activity, with a coal conversion efficiency of 93.7 % and an oil yield of 72.33 wt%. The fragmented shapes and lowed diameters of solid residue with prepared catalyst relative to no catalyst further displayed its significant roles in the inhibition of condensation reaction and coke formation.