Passivation of coker furnaces using combined mechanical and chemical means

A method comprising:

• displacing at least one cleaning pig in a coker furnace tubing;
• introducing a displacement fluid into the coker furnace tubing after the cleaning pig;
• introducing an inhibition composition into the coker furnace tubing after the displacement fluid, wherein the inhibition composition comprises a calcium or magnesium salt of dodecyl benzene sulfonate diluted in a hydrocarbon liquid;
• introducing a coker feed into the coker furnace tubing;
• and
• introducing an additional quantity of the calcium or magnesium salt of dodecyl benzene sulfonate into the feed intermittently.

A method comprising:

• displacing at least one cleaning pig in a coker furnace tubing;
• introducing a displacement fluid into the coker furnace tubing after the at least one cleaning pig;
• introducing an inhibition composition into the coker furnace tubing after the displacement fluid, wherein the inhibition composition has a pH from about 7.1 to about 8.0 and comprises a calcium or magnesium salt of dodecyl benzene sulfonate diluted in diesel in a volume ratio from about 3:7 to about 1:9;
• introducing a coker feed into the coker furnace tubing;
• and
• introducing an additional quantity of the calcium or magnesium salt of dodecyl benzene sulfonate in a concentration of from about 30 to about 75 ppm into the coker feed intermittently.