Coking and Visbreaking

Coking is a process for thermally cracking large molecules in residual oils into lower-boiling molecules, leaving behind the excess carbon in the form of petroleum coke—a coal-like material. Three major coking processes are delay coking, fluid coking and Flexicoking. Only coke from delay coking can be sold as commercial products. Coking is also a primary method of converting extra heavy oils and bitumenBitumen into synthetic crude oilsSynthetic crude oil (syncrudes). The primary purpose of visbreaking is not for conversion, but to reduce the viscosity and pour point of fuel oil. The two main types of visbreaking are coiled (short-contact) and soaker.