Petroleum Coke: Crude Oil Residue Coked in a Delayed Coker and Calcined

Petroleum coke is the solid carbon left from the heaviest part of crude oil. A refinery distils crude oil, then distils the residue again under vacuum, heats what is still left to about 480–505 °C and lets it crack in a coke drum. The drum fills with green coke in 12 to 24 hours; it is cut out with a water jet and calcined in a rotary kiln. Calcined coke feeds synthetic graphite and carbon anodes. The picture: our diagram of the route from crude oil to calcined coke.

متقدم

A day per coke drum

التعليمات

Distil the crude oil

Distil crude oil in an atmospheric column, slightly above atmospheric pressure. Draw off the lighter cuts, among them naphtha (boiling between about 30 and 200 °C), and keep the residue from the bottom, which boils above 370–380 °C.

المواد لهذه الخطوة:

النفط الخام1 t

الأدوات المطلوبة:

عمود التقطير الجوي

Distil the residue under vacuum

Distil that residue again at 10–40 mmHg absolute so it stays below 370–380 °C. The heavy bottoms left are the vacuum residue.

الأدوات المطلوبة:

عمود التقطير بالتفريغ

مضخة تفريغ

Heat and fill the coke drum

Pump the vacuum residue through the coker furnace to about 480–505 °C, with steam in the tubes, into a coke drum. It cracks there: gas oil and lighter parts leave as vapour and coke builds up in the drum, which fills in 12 to 24 hours.

الأدوات المطلوبة:

وحدة التكويك المتأخر

ماء

Quench and cut out

Switch the feed to the second drum. Steam out the full drum, fill it with water, wait several hours and drain it. Cut the coke out with a high-pressure water jet. This is green coke.

الأدوات المطلوبة:

وحدة التكويك المتأخر

ماء