Coking

The figure provided here illustrates the block diagram of a coking process.

Coking is a severe method of thermal cracking used to upgrade heavy residuals into lighter products or distillates.

Coking produces straight-run gasoline (coker naphtha) and various middle-distillate fractions used as catalytic cracking feedstock. The process reduces the hydrogen content of the residue (coke) to a large extent and it becomes almost a pure form of hard carbon.

The two most common processes are delayed coking and continuous (contact or fluid) coking. Three typical types of coke are obtained (sponge coke, honeycomb coke, and needle coke) depending upon the reaction mechanism, time, temperature, and the crude feedstock.