Cracking

Cracking helps meet this demand by breaking large hydrocarbon molecules into smaller, more useful molecules. Unlike fractional distillation, cracking is a chemical reaction: bonds within molecules break and new substances form. It converts less useful feedstock into valuable fuels and materials for the chemical industry.

Cracking goes further: it breaks larger, saturated alkane molecules into smaller, more useful molecules. Some products are smaller alkanes; others are unsaturated hydrocarbons called alkenes, which contain a carbon–carbon double bond.