Study on the production of low sulfur petroleum coke

High-quality low sulfur petroleum coke (LSPC) (sulfur content <0.5 wt.%) can be used to produce graphite electrode, which has high market demand and economic value. In this work, the sulfur distribution of delayed coking (DC) reaction of vacuum residue (VR) and ebullated-bed hydrotreating unconverted oil (UCO) was studied. The effects of different hydrotreating catalysts and different hydrotreating depths on the sulfur transfer of the coking reaction of UCO were investigated. The economic index of producing low sulfur petroleum coke was put forward, and the equation for predicting the sulfur content of petroleum coke was established. According to the economic index, it is suitable to use the catalyst with high desulfurization performance and low ring-opening performance to hydrogenate VR to produce LSPC. Meanwhile, it is not economical to adopt higher hydrogenation depth. According to the prediction equation, for UCO with a Conradson carbon residue (CCR) content of 25 wt.%, its sulfur content should be less than 0.25 wt% to produce high-quality low sulfur petroleum coke.