What is the principle otto -Hoffman carbonisation process?

The Otto-Hoffmann carbonization process is a method used to convert coal into coke by heating it in the absence of air, typically in a vertical chamber. This process involves the thermal decomposition of coal at high temperatures, which drives off volatile substances and leaves behind solid carbon. The resulting coke is porous and has a high carbon content, making it valuable for use in steel production and other industrial applications. Additionally, the process allows for the recovery of by-products like coal gas and tar, which can be utilized in various chemical processes.