The invention relates to the technical field of
coal tar hydrogenation, and particularly discloses a deep
denitrification method for preparing light
fuel oil by
coal tar hydrogenation. The method comprises the following steps: carrying out
filtration,
dehydration, demetallization and deasphaltene pretreatment on
coal tar, and carrying out a first-stage
hydrogenation reaction in the presence of a conventional catalyst; feeding the mixture into a second hydrogenation reactor filled with an N-P co-doped ordered
mesoporous carbon loaded Zr < 3 + > doped Ni2P catalyst, and carrying out hydrocracking and
oxygen introduction assisted in-situ regeneration; and finally, carrying out deep adsorption through a
nitric acid modified ZSM-5 and aluminum
oxide composite adsorbent to obtain the light
fuel oil. According to the invention, a multi-stage synergistic process of step-by-step impregnation and in-situ regeneration of the catalyst and B-Si dual auxiliaries and deep
denitrification of the composite adsorbent is adopted, so that the hydrodenitrification activity and the catalyst stability are enhanced, the
total nitrogen content of the product is effectively reduced, and the yield of light fractions of
gasoline and diesel oil is improved. The method is high in
denitrification depth, long in catalyst service life, capable of achieving efficient
resource utilization of
coal tar and suitable for industrial production.