Synergistic effect of blast furnace slag on the pyrolysis process of oil-rich coal, tar product distribution and kinetic analysis

Low-rank coal is used as raw material, solid waste blast furnace slag (BFS) rich in metal oxides is selected as catalyst. Co-pyrolysis experiment is carried out and explore the influence of different BFS particle size and doping amount on coal pyrolysis. The catalyst is characterized by FT-IR, XRD, TG, and the contribution degree and mechanism of BFS to the increase of oil-rich kerosene products are clarified. The results show that BFS exhibits good activity. When the added amount of BFS is 9%, the tar yield is as high as 14.65%. When the particle size is 2–5 mm, the tar yield is 14.1%. Adding BFS catalyst can improve the tar yield. By controlling the particle size and addition amount, the composition of the tar can be adjusted to achieve directional pyrolysis. According to coal kinetic analysis, when the temperature is 350–600℃, the overall activation energy in the pyrolysis process is the highest, and the first reaction is the most active.