Cracking

In [|petroleum geology] and [|chemistry], **cracking** is the process whereby complex [|organic] [|molecules] such as [|kerogens] or heavy [|hydrocarbons] are broken down into simpler molecules such as light hydrocarbons, by the breaking of [|carbon] -carbon [|bonds] in the precursors. The [|rate] of cracking and the end products are strongly dependent on the [|temperature] and presence of [|catalysts]. Cracking is the breakdown of a large [|alkane] into smaller, more useful [|alkanes] and [|alkenes]. Simply put, hydrocarbon cracking is the process of breaking long-chain hydrocarbons into short ones. More loosely, outside the field of petroleum chemistry, the term "cracking" is used to describe any type of splitting of molecules under the influence of heat, catalysts and solvents, such as in processes of [|destructive distillation] or [|pyrolysis]. There are different ways that cracking can occur. There is the process of fluid catalytic cracking, hydrocracking, and steam cracking. Fluid catalytic cracking is a commonly used process and was first used in around 1942. Hydrocracking started in 1920 and it is a catalytic cracking process assisted by the presence of an elevatedpartial pressure of hydrogen gas. Steam cracking is a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons

The term first came about in 1891.