Exploration and practice of producing low-sulfur petroleum coke in high-sulfur crude oil refineries

Objective The aim is to optimize the process flow of a high-sulfur crude oil refinery to produce low-sulfur petroleum coke.

Method By analyzing the process flow of petroleum coke production in a refinery, as well as the law of sulfur content data in delayed coking mixed feedstock and coke, the feasibility of producing low-sulfur petroleum coke was explored by optimizing the delayed coking mixed feedstock and petroleum coke production process flow and verified by industrial practice.

Result There was an obvious positive correlation between the sulfur content in delayed coking mixed feedstock and the sulfur content in petroleum coke, forming an empirical formula to predict the sulfur content in petroleum coke, which was verified to align with recent sulfur content in petroleum coke. By using the empirical formula, the residue hydrotreating-delayed coking combination process was an effective way to solve the problem of producing low-sulfur petroleum coke under the current conditions of processing high-sulfur crude oil, and it was capable of producing only 3^# petroleum coke when processing 20 wt% vacuum residue. When only catalytic cracking slurry and desulfurization residue were processed, 2^# petroleum coke could be produced by adjusting the ratio of feedstock.

Conclusion According to the feedstock ratio in the residue hydrotreating-delayed coking combination process scheme, the delayed coking unit of this refinery successfully produced 2B^# petroleum coke under the condition of processing high-sulfur crude oil, which confirmed the feasibility of the production scheme.