Mild hydrogenation pretreatment of FCC slurry oil for high-value-added utilization: Exploitable high-boiling components and carbonization discrepancy

In response to the enormous market demand for high-value-added carbonaceous materials and the urgent requirement of energy conservation and emission reduction, FCC slurry oil (SO) has drawn widespread attention in the preparation of these kinds of carbonaceous materials due to its abundant aromatic hydrocarbon contents. Distillation can be utilized as a pretreatment to efficiently remove the quinoline insoluble and other undesirable components in SO before carbonization. However, the distillate depth and yield are greatly restricted by the conspicuous coking phenomenon during thermal effect in the distillation. Mild hydrogenation coupled with distillation were adopted as the pretreatments before carbonization and effects of the hydrogenation on the distillation process were studied. Besides, transform patterns for the properties of sub-fractions in specimen before and after hydrogenation and resulted variations in carbonization performances were then systematically analyzed. Through hydrogenation, the distillation depth of hydrotreated SO (HSO) could be greatly improved to 530 degrees C with no significant coking phenomenon and the distillation yield was increased dramatically (from 38.4 wt% to 68.1 wt%). Especially, partial super high-boiling (above 530 degrees C) components in SO could be transformed into naphthenoaromatic structures by hydrogenation and acquired through distillation for further utilizations. Using anthracene as chemical probe, the hydrogen-donating abilities (HDAs) of specimens were detected, and results indicated the amounts of transferable hydrogen in HSO low-boiling and high-boiling sub-fractions were greatly increased compared with that of SO, which would provide the specimen with stronger stability in the thermal treatment and restrain the rapid coking. The carbonization performance varied with the properties of sub-fractions and a section of high-boiling components in SO was discovered to be exploitable through hydrogenation and demonstrated to be beneficial in the preparation of needle coke.

Automated summary

In response to the market demand for high-value-added carbonaceous materials and the need for energy conservation and emission reduction, the utilization of FCC slurry oil (SO) in the preparation of these materials has been studied. Mild hydrogenation coupled with distillation as a pretreatment method improves the depth and yield of distillation, and transforms certain high-boiling components into naphthenoaromatic structures that can be further utilized. The carbonization performance of the treated oil varies with its properties, and a section of high-boiling components is found to be exploitable for the preparation of needle coke.