Abstract:

The influence of cycle ratio on product distribution and properties of delayed coking process of Tahe atmospheric residue (Tahe AR) was studied in a pilot plant designed by R&D Center of Engineering and Technology of Sinopec Engineering (Group) Co., LTD. The results show that when the cycle ratio decreases from 0.92 to 0.39, the yields of gas and coke are reduced 1.71 and 2.57 percent points, however the yield of liquid product increases 4.17 percent points that benefit from the yield of coker gas oil (CGO) which increases 8.97 percent points. The reduction of the cycle ratio results in poor quality of CGO. Its density increases from 0.918 0 g/cm3 to 0.938 3 g/cm3, carbon residue enhances from 0.03% to 0.25%, and the temperature of 95% of vacuum distillation increases from 390 ℃ to 463 ℃. The CGO can be used as a component of mixed feed for hydrotreating process, though the difficulty of hydrotreating is enhanced.

Key words: Tahe atmospheric residue, delayed coking, recycle ratio, liquid yield, coker gas oil