Abstract: The scheme of using the existing diesel hydrotreating unit to produce reformer feedstock was studied. The effects of different types of hydrotreating catalysts, hydrocracking catalysts and conversion rate on hydrocracking reaction of diesel oil were investigated, and the suitable hydrotreating and hydrocracking catalyst system was selected. It was found that under the same reaction conditions, Ni-Mo hydrotreating catalyst had better hydrodesulfurization, denitrification and aromatics saturation performance, and was more suitable as a refining catalyst for hydrocracking of diesel oil to produce reformer feedstock. In light oil hydrocracking catalyst system, the aromatics and aromatic potential content of naphtha fraction were the highest, and in major middle oil hydrocracking catalyst system, the cetane number of diesel oil is higher. The yield of naphtha was increased from 6.47% to 10.47%, and the  aromatic potential content of naphtha was increased from 44.5% to 47.9% in a 2.6 Mt/a hydrotreating unit of diesel oil, to achieve the goal of structural adjustment of raw materials for producing more reformer feedstock with high aromatic potential content.

Key words: blended diesel, reformer feedstock, catalyst grading system, hydrocracking