Cracking and Hydrocracking

During cracking, larger molecules—those that boil above ~360°C (680°F)—are converted into naphthaNaphtha, keroseneKerosene, jet fuelJet fuel, dieselDiesel, heating oilsHeating oil, and light fuel oilsFuel oil. Cracking also generates light gases, LPGLiquified petroleum gas (LPG), and butanes. Light olefins (ethylene, propylene, and butenes) are produced byCracking, thermal thermal crackingThermal cracking, especially steam cracking, and catalytic crackingCracking, catalytic but not hydrocrackingHydrocracking. Thermal cracking has essentially been replaced by catalytic cracking. Catalysts used in catalytic cracking has been greatly improved in efficiency and size, which can be fluidized as fluid catalytic cracking (FCC). Hydrocracking achieves conversion with catalysts in the presence of excess hydrogen.  As with FCC, isoparaffins are produced preferentially.