Method for improving liquid yield in a delayed coking process

Abstract

A system and method for removing oil from the surface of coke left in refinery coke drums before it is cut out is disclosed. The process does not add time to the coking cycle, nor involve the addition of major equipment. A solvent is added to the stripping steam. The solvent could be either a hydrocarbon fraction such as a coker distillate, a light gas oil or another fraction having an end point below 450° C. The solvent-enhanced stripping steam becomes a very effective oil extraction vapor when injected into the coke drum.

1 . A process for removing residual liquid oil from a surface of coke in a vessel, said process comprising:
 (i) deriving steam from a steam source;   (ii) providing a hydrocarbon solvent;   (iii) delivering said steam into a coke drum containing said liquid oil on said surface of coke;   (iv) introducing a said hydrocarbon solvent into the steam being delivered; and   (v) removing said liquid oil in a vaporous effluent from said coke drum while the steam and hydrocarbon solvent are being delivered.