Study on In Situ Catalytic Cracking of Coal Tar by Plasma Preparation of the Pyrolysis Coke Catalyst

A two-stage pyrolysis fixed bed was used, and the vapor-modified pyrolysis coke was used as a carrier. A ZHPC catalyst was prepared by plasma calcination. Gas-phase tar produced by the pyrolysis of raw coal was subjected to in situ catalytic cracking to improve tar and gas yield. The effects of plasma calcination power, calcination time, and ZnO loading on in situ cracked products were studied. The prepared catalyst was characterized by X-ray electron spectroscopy, X-ray diffraction, Brunauer-Emmett-Teller, and scanning electron microscopy. The results showed that (1) compared with traditional catalysts, the catalyst prepared by plasma has better performance; (2) the optimal calcination time of the ZHPC catalyst is 5 min, calcination power is 60 W, and ZnO loading is 10%; (3) compared with raw coal pyrolysis, the optimal ZHPC catalyst on in situ catalytic cracking tar, gas yield increased by 66.16%; the cracking rate of tar increased by 54.46%, and the content of light components increased to 60.7%; (4) in situ catalytic cracking of tar with the optimal PC, the light tar has been greatly improved, in which the light oil, phenol oil, naphthalene oil, and wash oil have increased by 93.04, 126.31, 257.28, and 108.08%, respectively. The anthracene oil and asphalt have decreased by 26.98 and 58.71%; the tar cracking rate has increased.