Properties of semi-coke from co-pyrolysis of lignite and direct liquefaction residue of Shendong coal

In order to make use of coal direct liquefaction residue efficiently, co-pyrolysis of Hulunbuir lignite and direct liquefaction residue (DLR) of Shendong coal were conducted in a fixed bed reactor under atmospheric pressure. The physicochemical properties of co-pyrolysis semi-coke were analyzed by scanning electron microscope, nitrogen adsorption-desorption, X-ray diffraction, Raman spectroscopy and thermogravimetric analyzer. The results show that DLR semi-coke and lignite semi-coke are cohered each other, because the DLR is softened and melted during co-pyrolysis. The specific surface area and pore volume of co-pyrolysis semi-coke decrease. Characterization of both XRD and Raman spectroscopy indicate that the order degree of co-pyrolysis semi-coke increases with the addition of DLR. Compared with the lignite semi-coke, the CO₂ gasification reactivity of co-pyrolysis semi-coke decreases.