Study On The Effect And Mechanism Of Additives In Residue Hydroprocessing

Surfactant additives in the residue systems can play an effect of enhancing asphaltene stability, thus increase the system stability. Recent surfactant researches are focus on effect of its types and functional groups on dispersion of asphaltene and system stability. In this paper, some of the surfactants were added into reaction system, to investigate the effect of additives and its mechanism in residue hydroprocessing.The additives of different properties lead to a different results. DBSA with acidic functional groups has a best effect, followed by oleic acid. The light oil yield and residue conversion rate has increased despite the coke yield increased too. TBC with acidic functional groups and Fatty Amine with basic functional groups in the reaction have little positive effect. Polysorbate-80 with neutral groups, its coke yield increased slightly, the light oil yield and residue conversion rate decreased. The DASI reaction, although the residue conversion rate decreased slightly, the yield of light oil has little changes, and coke yield decrease a lot.The results of reactions under different operating conditions show the adaptability of additives on the operating conditions. Under different reaction temperature, initial hydrogen pressure and reaction time, the variation trend of residue conversion and the yield of each components of the reaction with additive are consistent with the reaction without additive. Higher reaction temperature and longer reaction time is not suitable for the effect of DBSA, and changes in initial hydrogen pressure have no significant effect.By increasing the stability of asphaltene, additives can improve the stability of the system to avoid heavy components accumulating too fast. Thus the addition of additives leads to a certain extent increasing of the light components. Asphaltene has relatively large structural change before and after hydroprocess. Compare with the reaction without additive, the asphaltene structural units of reaction with additive is smaller, asphaltene association degree is higher. Because of this, the light oil yield and residue conversion of reaction with additives is higher than the reaction without additives.