How is coke made?

Coke, also known as petroleum coke or petcoke, is a solid carbonaceous material derived from the refining of crude oil. Here is a general overview of how coke is made:

1. Crude Oil Distillation:

- Crude oil, which is a naturally occurring mixture of hydrocarbons, is heated in a distillation column.

- Different components of the crude oil vaporize at different temperatures and are separated into various fractions, including naphtha, gasoline, diesel, and heavier fractions.

2. Cracking:

- Heavier fractions, such as vacuum residue or gas oil, undergo a cracking process to break down large hydrocarbon molecules into smaller and more valuable molecules.

- This can be done through thermal cracking, where high temperatures are used to break the bonds, or catalytic cracking, which involves the use of catalysts to facilitate the process.

3. Coking:

- The cracked products from the cracking process are then directed to a coking unit.

- In a delayed coker, the feedstock is heated in a coking drum under high pressure to promote the formation of coke.

- As the hydrocarbons vaporize, the heavier molecules condense and accumulate on the walls of the drum, gradually forming a solid coke.

4. Cooling and Extraction:

- Once the coking process is complete, the coke drum is cooled to solidify the coke further.

- The solidified coke is then cut into large pieces using high-pressure water jets or mechanical cutting tools.

- The coke pieces are then extracted from the drum and sent for further processing or storage.

5. Calcination:

- In some cases, the coke may undergo calcination, which involves heating it in a controlled atmosphere to remove volatile matter and moisture.

- Calcination improves the coke's quality and makes it more suitable for specific applications.

The resulting coke is a highly carbonized material with a high fixed carbon content and low volatility. It is commonly used as a fuel source in various industries, including power generation, cement manufacturing, and metallurgy. Additionally, coke is used as a raw material in the production of steel and other ferrous alloys.