No. 1 FCCU in Jinling Petrochemical Company was revamped in 2001 to increase the processing ratio of vacuum residue. It was found later that the coke yield was increased after the revamping.

The first ratio is the normal area of the heap (80 percent used for normal processing), and the second is what we have defined for the large objects (20 percent for large-object allocation).

Instead, it matches the ratio found when organic molecules have been through a few rounds of biochemical processing.