What Is a Needle Coke?

Needle coke is used to make graphite electrodes.

Petroleum coke is a carbon-based solid manufactured at oil refinery coker units. The end product is a relatively pure collection of carbon that is resold as fuel or used in the manufacture of dry cells.

Acicular Coke

Acicular coke is highly crystalline, marketable coke derived from sweet crude oil, which is more commonly referred to as needle coke. The name itself is derived from the physical shape of the substance's grain structure. The solid is streaked in appearance, and breaks into needles.

Uses

Needle coke is highly prized within the steel and aluminum industries. It is used to produce graphite electrodes, which are used in furnaces. As electrodes are replaced on a regular basis, the value of this commodity increases, especially as the supply of sweet crude oil diminishes.

Production

Decant oil is preheated, separated, then reheated to induce an endothermic reaction during the coking process. The resulting green coke is dried using superhot gasses, which reduces the volatile matter and hardens the coke. Water blasted into the drying drum cuts, or removes, the coke.

References

• Sea Drift Coke: Process Description
• Asbury Carbons: Calcined Needle Coke
• IUPAC: Needle Coke