Gas-Modified Pyrolysis Coke for in Situ Catalytic Cracking of Coal Tar

Modified pyrolysis coke can be used as a catalyst for tar cracking. In this paper, pyrolysis coke was used as a carrier for modification by using gases (H₂O, CO₂, and NH₃), and the optimal modified gas was selected. On the basis of this, pyrolysis coke with different modified flow rates, temperatures, and times were prepared to catalyze the cracking of tar. The effect of gas-modified pyrolysis coke on tar cracking products was studied. Also, pyrolysis coke was characterized by Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and scanning electron microscopy. The results show that the optimal gas is H₂O, and the optimal preparation conditions are 450 mL/min, 650 °C, and 60 min. The pyrolysis coke catalyst under the optimal conditions has the best cracking effect on tar. Also, the gas and tar yields have been further improved.