Abstract: By analyzing the properties of the feedstock, main operating conditions and product properties in the later stage of residue oil hydroprocessing, the desulfurization rules and sulfur distribution during the hydrogenation process were explored. The results show that the sulfur in the mercaptans and sulfides of the light fractions (≤ 350 ℃) of the feedstock is relatively easy to remove, and the remaining refractory benzothiophene and dibenzothiophene are in the hydroprocessed heavy oil. The heavy fractions (>350℃) of the feedstock contain a large amount of thiophene and cyclic sulfide sulfur compounds, and the hydroprocessed heavy oil heavy fractions are mainly dibenzothiophene sulfides with an equivalent double bond number greater than or equal to 9. The mercaptans and thiophenes containing long-chain alkane structures have low conversion rates due to large steric hindrance. Increasing the cycloalkane substituents can reduce the steric hindrance and increase the conversion of the corresponding sulfur compounds. When the number of rings (cycloalkanes and aromatics) of the sulfur compounds increases to five or more, the conversion rate of the sulfur compounds begins to decrease significantly due to the internal diffusion effect.

Key words: residue hydrotreating, desulfurization, sulfur distribution, sulfur conversion