Objective In response to the challenge of high-quality crude oil shortage, solvent deasphalting technology is innovated to fully tap into the potential value of heavy crude oil and enhance the overall utilization efficiency of crude oil.

Method In the solvent deasphalting system, a laboratory-synthesized modifier was used to treat coking feedstock oil, and experimental research on solvent deasphalting of the modified feedstock oil was carried out. The modification effects of different modifier dosages, modification temperature and modification time on coking feedstock oil were compared, and the effects of the solvent-to-oil mass ratio (hereinafter referred to as solvent-to-oil ratio), extraction temperature and ultrasonic extraction time on the deasphalting effect of modified feedstock oil were investigated.

Result When the mass fraction of the modifier in the coking feedstock oil was 0.4%, the modification temperature was 80 ℃, and the modification time was 60 min, 58.62% of the resins and all the asphaltene in the coking feedstock oil underwent a modification reaction. This reaction formed alkane solvent-insoluble substances with higher relative molecular mass and stronger polarity, while the proportion of ideal components (saturates and aromatics) remained unchanged. In the deasphalting stage, with n-heptane as the solvent, under the conditions of solvent-to-oil ratio of 2.0∶1, extraction temperature of 50 ℃, and an ultrasonic extraction time of 10 min, the mass yield of deasphalted oil (DAO) reached 75.85%, the mass yield of deoiled asphalt (DOA) was 24.15%, and the asphaltene removal rate achieved 100%.

Conclusion The modifier exhibits a modification effect on the coking feedstock oil, which can reduce the solvent-to-oil ratio and improve the efficiency of solvent deasphalting.